SYSTEM AND METHOD FOR FLIGHT CONTROL OF AN AIRCRAFT WITH A ROTATING SAILING SYSTEM WHILE TAKING A TR

专利摘要:
The present invention relates to a method and a flight control system (1) for rotary wing aircraft (10). A first mode of operation of said method makes it possible, when the longitudinal speed Ux of said aircraft (10) is greater than a first threshold speed Vseuil1, to perform a flight with a course of flight relative to the ground, the flight instructions of a pilot automatic (15) being a ground road angle TKsol, a forward speed Va, a slope P and a heading Ψ. A second mode of operation makes it possible, when said longitudinal speed Ux is less than a second threshold speed Vseuil2, to perform a flight with heading stability, said flight instructions being said longitudinal speed Ux, a lateral speed VY, a vertical speed Wz and said heading Ψ.
公开号:FR3023017A1
申请号:FR1401474
申请日:2014-06-30
公开日:2016-01-01
发明作者:Lavergne Marc Salesse
申请人:Airbus Helicopters SAS；
IPC主号:

专利说明:

[0001] BACKGROUND OF THE INVENTION The present invention is in the field of flight control systems for rotary wing aircraft, and more particularly for aircraft flight control systems and methods for controlling the flight of a rotary wing aircraft in course of flight or course keeping. assistance with the use of such flight controls such as an autopilot. The present invention relates to a method for controlling the flight of a rotary wing aircraft in course of flight or heading stability according to its longitudinal travel speed thus forming a "full envelope" flight control method, that is, that is, covering both low-speed, high-altitude and high-speed flight phases near the ground. The present invention also relates to a flight control system 15 of a rotary wing aircraft in course of flight or course keeping according to its longitudinal travel speed. Rotary wing aircraft are flying aircraft that are distinguished primarily from other powered aircraft by their ability to evolve both in high speed cruise flight and low speed or hover flight. Such capacity is provided by the operation of at least one main rotor with substantially vertical axis of rotation equipping the aircraft. This main rotor is a rotary wing providing lift or even propulsion of the aircraft. The behavior of the aircraft with rotary wing in flight can be modified from a variation of the cyclic pitch and / or the collective pitch of the blades of the rotary wing. A variation of the cyclic pitch of the blades induces a modification of the behavior of the aircraft in attitude, and more particularly in pitch and / or roll. A variation of the collective pitch of the blades induces a modification of the behavior of the aircraft in lift, which can generate displacements particularly along a substantially vertical axis, but also along its axes of pitch and roll according to the attitude of the aircraft. The rotary wing aircraft is also operable in a yaw on itself, from the operation of a yaw anti-torque device. For example, such an anti-torque device is formed of a tail rotor with a substantially horizontal axis of rotation located at the rear of the aircraft. Such a rear rotor has several blades, generally only the collective pitch is variable although the cyclic pitch can also be variable. A rotary wing aircraft generally comprises a single main rotor and a rear anti-torque rotor. However, a rotary wing aircraft may also comprise two main counter-rotating rotors, for example in tandem or coaxial, no anti-torque device then being necessary. In addition, a hybrid helicopter is a rotary wing aircraft comprising at least one main rotor, mainly providing its lift and, to a lesser extent, its propulsion, and at least one specific propulsion means such as a propulsion propeller. Such a hybrid helicopter can cover great distances and evolve with a high forward speed. The anti-torque device of this hybrid helicopter can be formed by at least one propellant propeller. Such a propeller propeller has several blades, generally only the collective pitch is variable. In addition, a rotary wing aircraft may comprise aerodynamic elements such as empennages or even wings in the case of hybrid helicopters in particular. These aerodynamic elements may include moving parts and participate in the maneuverability of the aircraft and in particular during cruising flight at high forward speeds.
[0002] A variation of the flight behavior of the rotary wing aircraft can then be made from a modification of different flight parameters of the aircraft. These different flight parameters concern in particular the cyclic and / or collective pitch values of the main rotors as well as the collective pitch value of the anti-torque rotor and / or the propulsion means and the possible aerodynamic elements. Such a modification of these flight parameters can be carried out according to various control modes. According to a manual control mode, the pilot of the rotary wing aircraft has control levers manually driven by this pilot of the aircraft to operate a variation of these flight parameters including cyclic and / or collective pitch of the blades different rotors via kinematic chains of manual control. The notion of manual is to be considered in opposition to the concept of automatic, without prejudging the means used by man to maneuver the aircraft, rudder, joystick or handle in particular. According to one embodiment of a manual control mode, the control levers are engaged on respective chains with mechanical transmission remote forces, allowing the pilot of the rotary wing aircraft to mechanically maneuver the blades from the control levers, either directly or via servo controls. According to another embodiment of a manual control mode, a drive of a control lever by the pilot is generating electrical activation signals of at least one blade servo control. According to an automated control mode, an autopilot generates control commands for these flight parameters and in particular a variation of the pitch of the blades of the different rotors via automated control kinematic chains. When the autopilot is activated, the control commands are substituted for the command commands generated by the pilot directly from the control levers to activate the servocontrols. The autopilot makes it possible to maintain a stable progression of the rotary wing aircraft according to previously memorized flight instructions. An actual state of progress of the aircraft is evaluated by the autopilot at a given time with respect to various information provided by the aircraft instrumentation. From a difference detected by the autopilot between the flight instructions and the actual state of progress of the aircraft, the autopilot intervenes on the flight behavior of the rotary wing aircraft via one or more flight parameters to restore its actual progress status in accordance with the flight instructions. The activation of the autopilot is controlled by the pilot of the rotary wing aircraft from one or more specific control buttons. According to a stabilization mode implemented by the autopilot, an initial attitude of attitude keeping of the aircraft with rotary wing is for example defined with respect to the state of progress of the aircraft evaluated from the automatic driver activation 30. The stabilization mode provides a stabilization of the aircraft by attitude correction of the aircraft by means of the autopilot compared to the initial setpoint. According to a particular mode of piloting by transparency, the pilot can possibly intervene temporarily on the behavior of the aircraft by means of the control levers, by surpassing the control commands generated by the autopilot. The initial flight instructions are fixed, a possible temporary intervention of the pilot on the behavior of the aircraft does not induce modification of the initial flight instructions. It is also known to correct a flight setpoint such as a trim hold setpoint according to the actual progress state of the rotary wing aircraft at the end of a pilot action on the control levers. . It is still known to allow the pilot of the aircraft to correct a set attitude setpoint by varying the value of this setpoint by incrementing, through one or more dedicated control organs. For example, two control devices generally designated by the term "beep" are used.
[0003] For example, such control members can be positioned respectively on a collective pitch control lever generally called a "handle" and a cyclic pitch control lever. FR1347243 discloses a transparency control device for a pilot action with either a return to the initial flight instructions after stopping the action of the pilot and is a record of new flight instructions taking into account this action of the pilot. Also known is document FR2991664, which describes an automated piloting assistance system making it possible to hold a flight parameter on an axis of progression of the aircraft while taking into account the action of the pilot of the aircraft on at least one aircraft. another axis via flight control levers during operation of the autopilot of the aircraft. Different guidance modes are likely to be selected by the pilot favoring for example a holding in vertical speed or advancement or cap, incidence or slope behavior. In addition, document US5001646 describes an automated control system allowing the pilot to act on the progression of the aircraft via a control member provided with four axes. The pilot can then control the longitudinal, lateral and vertical accelerations of the aircraft as well as its angular velocity while maintaining, on the one hand, at a low speed of advancement, a speed relative to the ground independently of the course followed and on the other hand, at high speed, a coordinated turn and a slope. The stabilization of the rotary wing aircraft is provided from basic modes, according to which the autopilot is for example generating a stability increase by damping the angular movements of the aircraft, or even holding plates or cap. The basic modes provide piloting comfort for the pilot of the rotary wing aircraft, but do not correct any deviations from the speed or position of the aircraft desired by the pilot. It has therefore been proposed to associate the basic modes of the higher modes of operation to cancel any deviations of position, speed and / or acceleration of the aircraft from the values desired by the pilot. These desired values are entered as flight instructions which the higher modes of the autopilot use to bring and maintain the aircraft at the desired position, speed and / or acceleration. The aircraft stabilization operation provided by the base modes is performed quickly by the autopilot, while the recovery operation of the position, speed and / or acceleration of the wing aircraft rotating is then performed more slowly by the higher modes. Document WO95 / 34029, for example, is known which describes an aircraft flight control system making it possible to stabilize the speeds of the aircraft by controlling the commands according to the yaw, roll and pitch axes as well as the lift while maintaining a constant course. The autopilot is still likely to provide advanced guidance assistance functions for the rotary wing aircraft. The potentialities offered by the higher modes are incidentally exploited to provide such assistance. The modes of execution of the advanced functions fall under predefined functionalities of the autopilot, with regard to a set trajectory that the aircraft must follow. In fact, the operation of such higher modes of autopilot is designed for IFR operations designating in English "Instruments Flight Rules", that is to say for a piloting that can be carried out only with the aid of flight instruments and can then be realized with an external vision of the degraded aircraft, or no external vision. In contrast, visual piloting is performed according to VFR operations designating in English "Visual Flight Rules". The English expression "piloting eyes-out" is also used and means that the pilot is piloting the aircraft by looking outside the aircraft and not only using the instruments and flight assistance. .
[0004] The set trajectory is for example exploited with regard to a flight mission previously determined by the pilot of the rotary wing aircraft or in the approach phase of a known and spotted site. Such a site is notably equipped with means providing interactivity between the site and the autopilot, such as radio navigation beacons. In the absence of such interactive equipment, the location of the site is performed by the pilot of the aircraft in manual mode, then, the pilot of the aircraft activates the desired advanced function.
[0005] The operating modes of the autopilot allow automated assistance steering steering correction of attitude of the rotary wing aircraft in the cruising flight phase, high forward speeds and a position of the aircraft away from the ground. During the cruise flight phase, the environment of the aircraft is normally cleared and the pilot of the aircraft is exempted from a sustained intervention on the maneuvering of the aircraft. Such a sustained intervention exemption is also likely to be provided near the ground in known environment by the implementation of an advanced function of the autopilot, such as for an approach phase of an airstrip. known and / or equipped with means for locating its environment. Similarly, during an approach phase of an intervention site, including at low speeds, perfectly known, identified and identified by the autopilot, the activation of an advanced function is made possible to guide the rotary wing aircraft following the corresponding reference trajectory. In addition, the autopilot controls, as a man piloting the aircraft, traditionally the longitudinal, lateral and vertical speeds of the aircraft respectively by the longitudinal cyclic pitch, the lateral cyclic pitch and the collective pitch of the main rotor, the pitch collective anti-torque rotor controlling the orientation of the aircraft around its yaw axis. These longitudinal, lateral and vertical speeds are defined in a reference linked to the aircraft whose axes are formed by the longitudinal, lateral and vertical directions of the aircraft. In addition, an autopilot may also allow the aircraft to make coordinated turns. A coordinated bend is a bend made without drifting the aircraft with respect to the path of the turn relative to the ground, it is then a ground coordination, or without lateral load factor, it s' then acts of an air coordination. In the case of ground coordination, a turn is coordinated with the ground. The aircraft has no drift vis-à-vis the ground, and can accurately track a path on the ground. Such a coordinated turn with respect to the ground is preferably used at low speed and low altitude in order to move safely near the terrain or buildings, the nose of the aircraft generally remaining aligned with the ground track.
[0006] In the case of air coordination, a turn is coordinated with respect to the air. The aircraft has no drift with respect to the air and thus privileges the comfort of the occupants and minimizes the skidding of the aircraft. Such a coordinated turn with respect to the air is preferably used in cruising flight, that is to say at high speed and high altitude and far from any obstacle. US5213283 discloses a control system for performing a coordinated turn. This control system automatically provides a yaw control command in response to a pilot roll command from the pilot of the aircraft when performing such a coordinated turn, thereby reducing the pilot load. In addition, WO2012 / 134447 discloses an aircraft flight control system for performing a coordinated turn throughout the flight range, minimizing the pilot workload. This control system uses high speed on the one hand changes of inclination of the aircraft to control the course and a lateral acceleration and on the other hand the speed relative to the air of the aircraft to fly 10 course, making a coordinated turn relative to the air. At low speed, the control system uses the aircraft's skid angle to maintain the heading aligned with the flight path of the aircraft, thereby achieving a coordinated turn relative to the ground. In a transition zone between these two flight domains, the aircraft's skid angle and lateral acceleration are used to maintain the aircraft in a coordinated turn. In addition, the rotary wing aircraft are powered aircraft intended to be able to operate under various and sometimes difficult conditions, both in terms of the atmospheric conditions, such as the presence of a strong wind and variable visibility conditions, that flight conditions, such as at low speeds or hovering, or the environment, such as close to any unknown or poorly known soil. In difficult flight conditions, unexpected factors are likely to be taken into account by the pilot of the rotary wing aircraft. The operation by the pilot of the aircraft of automated assistance to maneuver the aircraft in such difficult flight conditions is therefore difficult or impossible. For example, when the aircraft is close to the ground, a possible modification of its behavior must be quickly made. The operating modes of the autopilot make it difficult to quickly change a trajectory to be followed by the aircraft by operating an advanced function implementing the higher modes of operation of the autopilot. In fact, during such difficult flight conditions, the use of an IFR control can be dangerous and visual piloting is preferred, the pilot can however use certain instruments and / or assistance of the aircraft. These include visual flight conditions under VMC conditions corresponding to the English acronym "Visual Meteorological Conditions" or in degraded visibility conditions DVE corresponding to the English acronym "Degraded Visual Environment". The pilot may then need to frequently adjust the speed and / or trajectory of the aircraft in order to avoid possible obstacles and to get closer to its objectives, for example in the event of a strong side wind. The document FR2777535 describes a flight control system of an aircraft allowing in particular to control the lateral speed with respect to the ground while keeping a constant course in order to compensate for example a strong side wind. This control system also makes it possible to maintain the direction of the speed of the aircraft, and therefore its trajectory, constant during a modification of its heading and / or its longitudinal speed.
[0007] Moreover, document WO2012 / 134460 describes a flight control system of an aircraft making it possible to maintain a constant trajectory with respect to the ground during a rotation of course at low speed. The control system acts on the pitch and roll controls to maintain this trajectory, the pilot being able to engage a rotation of the aircraft at any time via these commands.
[0008] Similarly, the document WO2012 / 096668 describes an aircraft flight control system making it possible to control the vertical speed of the aircraft, its slope relative to the ground and / or a height with respect to the ground according to its speed of flight. advancement. Below a predetermined forward speed threshold, corresponding to a flight situation close to a hover, the flight control system makes it possible to maintain a height relative to the ground. Above this predetermined forward speed threshold, the flight control system then makes it possible to maintain a vertical speed of the aircraft or a slope relative to the ground. In addition, the document FR2814433 describes a flight control device of an aircraft whose action on a control member may have different effects depending on the speed of translation of the aircraft. Thus, if this translation speed of the aircraft is less than or equal to a predetermined threshold, an action on this control member acts directly on this translational speed. On the other hand, if this speed of translation of the aircraft is greater than this predetermined threshold, an action on this control member acts, for example, on the acceleration in translation of the aircraft or on its angular velocity. Finally, the document W02013 / 012408 describes a flight control system of an aircraft making it possible to automatically hijack the aircraft from a forward flight as well as holding in position. hovering. The subject of the present invention is therefore a flight control method as well as a flight control system making it possible to achieve a trajectory hold or a heading hold of a rotary wing aircraft according to its longitudinal speed U x while overcoming the limitations mentioned above. According to the invention, a method for controlling the flight or course keeping of a rotary wing aircraft is intended for a rotary wing aircraft comprising at least one control member, provided jointly with several axes of rotation. mobility A, B, C, D, and an autopilot generating control commands according to predefined modes of operation and according to flight instructions.
[0009] The aircraft is characterized by three privileged directions, a longitudinal direction X extending from the front of the aircraft towards the rear of the aircraft, a direction of elevation Z extending from bottom to top perpendicular to the longitudinal direction X and a transverse direction Y extending from right to left perpendicular to the longitudinal directions X and elevation Z. The longitudinal direction X is the roll axis of the aircraft, the transverse direction Y is its pitch axis and the elevation direction Z is its yaw axis. The aircraft comprises at least one rotary wing, provided with several main blades whose collective pitch and the cyclic pitch are variable around a pitch axis, allowing the aircraft to make rotational movements around these directions X , Y, Z and translation along the X, Y, Z directions. The autopilot control commands can cause these movements of the aircraft in rotation and / or in translation with respect to the X, Y, Z directions. The flight control method is remarkable in that on the one hand a first operating mode of the control members and the autopilot is applied when the longitudinal speed Ux of the aircraft is greater than a first threshold speed Vseuill , the autopilot then allowing the aircraft to perform a flight with a course of flight relative to the ground, the flight instructions of the autopilot being a ground ground angle TKsol, the forward speed Va, a slope P, and a course y, and secondly a second mode of operation of the control members and the autopilot when the longitudinal speed Ux is less than a second threshold speed VseuiI2, the autopilot then allowing the aircraft to perform a flight with course keeping, the flight instructions of the autopilot being the longitudinal velocity Ux, a lateral velocity Vy, a vertical velocity Wz and a heading tp. The longitudinal speed Ux of the aircraft is a projection of the forward speed Va of the aircraft on the longitudinal direction X.
[0010] The rotary wing aircraft comprising at least one rotary wing with a substantially vertical axis of rotation, that is to say parallel to the elevation direction Z, can be constructed according to several architectures. The aircraft comprises for example a single rotary wing formed by a main rotor providing lift and propulsion of the aircraft and an anti-torque rear rotor with substantially horizontal axis of rotation, that is to say parallel to the direction Y. This rear anti-torque rotor also allows maneuvers around the yaw axis. In another example, the aircraft comprises two rotary wings formed by two main rotors contrarotating which are tandem or coaxial. The aircraft may also include at least one rotary wing, such as a main rotor, mainly providing lift for the aircraft and one or more propeller propellers with substantially horizontal axes of rotation, that is to say parallel to the longitudinal direction X, ensuring his propulsion. Such an aircraft then constitutes a hybrid helicopter. In addition, a rotary wing aircraft may include aerodynamic elements such as empennages or wings in the case of hybrid helicopters in particular. These aerodynamic elements may include moving parts to facilitate the maneuverability of the aircraft especially during a cruising flight. Whatever the architecture of the aircraft, the pilot of the aircraft can modify the flight behavior of the aircraft by acting on one or more control levers causing a variation of the cyclic pitch and / or collective pitch of the blades. main members of each rotary wing and a control means such as a rudder causing a variation of the collective pitch of the secondary blades of a rear rotor or such a joystick causing a variation of the collective pitch of the secondary blades of at least one propeller propeller . Similarly, the pilot of the aircraft can also cause a displacement of the moving parts of the aerodynamic elements possibly present on the aircraft in order to modify the flight behavior of the aircraft. In addition, the autopilot can also modify the flight behavior of the aircraft through the commands he commands and according to the flight instructions, causing a variation of the cyclic pitch and / or the collective pitch of the aircraft. main blades of each rotary wing, a variation of the collective pitch of the secondary blades of a rear rotor or at least one propeller propeller as well as a displacement of the moving parts of the aerodynamic elements possibly present. These variations of pitch and these displacements of moving parts make it possible to generate rotations and / or translations of the aircraft with respect to these X, Y, Z directions or variations of its angular and / or linear speeds with respect to these same directions X, Y, Z. These rotations and translations of the aircraft occur according to a reference linked to the aircraft and formed by the directions X, Y, Z. The aircraft generally moves along a trajectory Ts., Determined with respect to the ground in order to reach a ground objective such as an airstrip. It is considered that the aircraft is moving along a trajectory Ts., When its center of gravity follows this trajectory Ts01. In fact, this trajectory Ts., Is defined in a terrestrial geographical reference, that is to say fixed with respect to the terrestrial globe, in which the aircraft is mobile. This terrestrial geographical landmark is for example formed from the cardinal points, for example by the north and east directions and by a vertical direction such as that of the Earth's gravity. The flight of an aircraft according to this trajectory Ts., Can be characterized, according to a first type of characterization, by a ground road angle TKs., Taken with respect to the direction of magnetic north or of geographic north, in a plane horizontal of this terrestrial geographical reference point, a forward speed Va, a slope P and a heading (p The forward speed Va of the aircraft is its speed along the direction of this trajectory Ts01. can be the speed of advance of the aircraft relative to the ground or the speed of advancement of the aircraft relative to the air.The speed of advance of the aircraft from the ground is generally used as forward speed Va during flights at low altitudes, that is to say the aircraft being close to obstacles such as terrain and buildings The speed of movement of the aircraft relative to the air as for it is used as speed of progression Va essentially during the cruising flights at high altitudes, that is to say the aircraft being away from any obstacle. The slope P of the aircraft is the angle formed by the longitudinal direction X of the aircraft relative to a horizontal orientation of the terrestrial reference in which the trajectory Ts01 is defined, that is to say with respect to a plane perpendicular to the vertical direction formed by the direction of Earth's gravity. The heading (y of the aircraft is the angle formed by the projection in the horizontal plane of the terrestrial reference of the longitudinal direction X of the aircraft and the direction of the north, thus, when the heading tp and the driving angle TKsol ground are equal, the nose of the aircraft points on the trajectory Ts01.Thus, the longitudinal direction X is then aligned on this trajectory Ts01.In the opposite case, the nose of the aircraft is not on this track. trajectory Ts01 and this trajectory Ts01 is not then aligned in the longitudinal direction X, a rotary wing aircraft having the distinction of being able to advance in all directions independently of its longitudinal direction X.
[0011] The flight of an aircraft along this trajectory Ts01 can also be characterized, according to a second type of characterization, by a speed along the three preferred directions X, Y, Z of the aircraft, that is to say a longitudinal speed Ux in the longitudinal direction X, a lateral velocity Vy in the transverse direction Y and a vertical velocity Wz in the elevation direction Z as well as by the heading tp. These longitudinal speeds Ux, lateral Vy and vertical Wz are the components according to these three preferred directions X, Y, Z of the aircraft of the speed of advance of the aircraft and preferably the speed of advance of the aircraft. compared to the ground.
[0012] This second type of characterization of the trajectory Tsol is directly related to the displacement capabilities of an aircraft in rotation around the X, Y, Z directions and in translation along the X, Y, Z directions. Indeed, a rotary wing aircraft generally comprises at least one first control lever, also called handle, for modifying the cyclic pitch of a main rotor and a second control lever for modifying the collective pitch of this main rotor. . This first control lever has two axes of mobility and thus makes it possible to simultaneously control rotational movements of the aircraft around the longitudinal X and transverse Y directions and, consequently, to act on the longitudinal Ux and lateral Vy velocities of the aircraft. The second control lever comprises a single axis of mobility and makes it possible to control the translational movements of the aircraft in the direction of elevation Z and, consequently, to act on the vertical speed Wz of the aircraft. In addition, such a rotary wing aircraft generally comprises a rudder for controlling an anti-torque device, for example by modifying the collective pitch of an anti-torque rear rotor, and thus to control the yaw angle of the aircraft and, consequently, his course there. Such an aircraft can also have, when it comprises aerodynamic elements provided with moving parts, control means making it possible to control the movement of these moving parts and consequently to modify the plates of the aircraft in order to act on the longitudinal velocities Ux, lateral Vy and vertical Wz of the aircraft. The displacement of these moving parts can also be coupled to the first and second levers. This second type of characterization of the trajectory Ts01 is particularly adapted to the flight of the aircraft at a very low speed of advancement by guaranteeing the cap of the aircraft to be held in order to evolve with constant exposure to the wind and to minimize the modification of the visual references of the pilot of the aircraft. This second type of characterization of the Tsol trajectory can in particular be used in particular cases such as maintaining a hovering position or moving around a hovering position or a winching from a boat which advanced. Indeed, the direct control of the longitudinal velocity Ux, lateral Vy and vertical Wz of the aircraft without changing the heading y of the aircraft makes it possible to fly close to a winching or landing objective and to easily adjust the position of the apparatus with respect to such an objective, for example by a lateral or vertical displacement. The independent modification of the course allows it to choose a heading giving a desired exposure of the aircraft to the wind or the desired visibility of the objective and then maintain this heading ip during subsequent speed adjustments. The first type of characterization of the Tsol trajectory is more suitable for high altitude cruising flight by guaranteeing a Ts01 trajectory keeping in order to directly modify the TKsol road angle irrespective of the forward speed Va and the slope P, or only this forward speed Va or the slope P. Indeed, in this case, in response to an action around the roll axis controlled by the pilot of the aircraft, the nose of the aircraft rotates in order to try to remain aligned with the Tsol trajectory followed by the aircraft, thus facilitating the tracking of this trajectory Ts01, but limiting or even canceling the discomfort created by the roll tilt of the aircraft. However, this first type of characterization of the trajectory Ts01 can also be used during a low-altitude flight in order to approach an objective such as a landing ground along this trajectory Ts01.
[0013] On the other hand, the first type of characterization of the trajectory Ts01 is not related directly and simply to the displacement capabilities of the aircraft. Indeed, when the pilot wants to modify one or more parameters of this first type of characterization of the trajectory Tsol, it can not act directly on the ground road angle TKsoi, the forward speed Va, the slope P and the cap y. The pilot must in fact generally act simultaneously on several flight parameters among the collective and cyclic pitch of the main blades of at least one main rotor and possibly the collective pitch of a rear rotor or at least one propeller or the propeller. moving at least one moving part of aerodynamic elements. Moreover, it is almost impossible for the pilot, by manually acting on the flight parameters, to modify only one of these parameters of the trajectory Ts., Without at least one other parameter of the trajectory Ts01 being modified. In addition, according to the architecture of the rotary wing aircraft, it is possible to modify at least one of these parameters of the trajectory Ts01 by acting indifferently on several flight parameters of the aircraft.
[0014] For example, the forward speed Va of a hybrid helicopter can be modified by acting either on the propellers or on the main rotor. On the other hand, if the heading y of this aircraft is different from its ground ground angle TKsol, the single action on the propeller propellers or the main rotor will change the forward speed Va, but also the ground road angle TKsoi. Thus, the flight of an aircraft along a path Ts01 can be characterized by these two types of characterization, either by a ground road angle TKsoi, a forward speed Va, a slope P, and a course y, or by a longitudinal velocity Ux, a lateral velocity Vy, a vertical velocity Wz and a course y.
[0015] The flight control method according to the invention makes it possible to switch between a first mode of operation of the control members and the automatic pilot according to the first type of characterization of the trajectory Ts01 and a second mode of operation of the control members and the autopilot according to the second type of characterization of the trajectory Ts01 as a function of the longitudinal velocity Ux of the aircraft. This second operating mode of the control members and the autopilot is thus used for low forward speeds Va, the first operating mode being used at higher forward speeds Va. Thus, when the longitudinal velocity Ux is greater than the first threshold velocity Vseuill, the autopilot enables the aircraft to fly with a flight attitude relative to the ground, the flight instructions of the autopilot being the angle ground road TKsoi, forward speed Va, slope P and heading tp. On the other hand, when this longitudinal speed Ux is lower than the second threshold speed VseuiI2, the autopilot then allows the aircraft to make a flight with a heading hold, the flight instructions of the autopilot being the longitudinal speed Ux, the lateral velocity Vy, the vertical velocity Wz and the cape tp. However, the evolution of the aircraft along a slope P only makes sense from a certain forward speed of the order of 25 knots (20 knots). In fact, when the forward speed of the aircraft is lower than a third threshold speed Vseuil3 typically equal to 20kt, but in the range of speed of a course of flight, the piloting of the aircraft can be achieved by replacing the flight instruction corresponding to the slope P by a flight instruction corresponding to the vertical speed Wz.
[0016] In addition, the switching between the first and the second operating mode of the control members and the autopilot is with respect to a hysteresis threshold according to the threshold speeds Vseuill and VseuiI2, the first threshold speed Vseudi being greater than the second speed. threshold VseujI2. The term "hysteresis threshold" is understood to mean a threshold set whose activation setpoint for a system is different from its stopping setpoint. Such a hysteresis threshold consists of a different high threshold and a lower threshold. The presence of these two thresholds essentially prevents too many activations or too many consecutive stops. In the case of the method according to the invention, the high threshold is the first threshold speed Vseuill and the low threshold is the second threshold speed VseujI2- Thus, the first operating mode of the control members and the autopilot is engaged as soon as the longitudinal speed Ux exceeds the first threshold speed Vseuill and remains engaged as long as the longitudinal speed Ux is greater than or equal to the second threshold speed Vseud2. Similarly, the second operating mode of the control members and the autopilot is engaged as soon as the longitudinal speed Ux becomes lower than the second threshold speed Vseuil2 and remains engaged as long as the longitudinal speed Ux is less than or equal to the first threshold speed Vseudi. In addition, the threshold speeds Vseudi and VseuiI2 may be a function of the flight conditions of the aircraft, essentially of the longitudinal velocity of the relative wind experienced by the aircraft as well as the lateral speed Vy of the aircraft. Indeed, according to the longitudinal velocity of the relative wind experienced by the aircraft, the nose of the aircraft can be aligned with the trajectory Ts01 of the aircraft or be closer to the wind direction. For example, at low longitudinal speed Ux, a pilot will preferably maintain the alignment of the nose of the aircraft on the wind direction in strong winds rather than crosswind. Conversely, for the same longitudinal speed Ux low, this pilot will align the nose of the aircraft in the trajectory Ts01 of the aircraft when the wind is weak and keep the nose in the direction of the wind in strong winds. Making these thresholds dependent on the projection of the wind on the longitudinal axis of the aircraft thus allows to get closer to what a pilot does naturally. The longitudinal velocity of the relative wind experienced by the aircraft is understood to mean a projection on the longitudinal direction X of the velocity of this relative wind experienced by the aircraft. By convention, it is considered that a longitudinal velocity of the relative wind experienced by the aircraft is positive when the aircraft is subjected to headwind and such a longitudinal wind speed is negative when the aircraft is subjected to downwind. For example, with a headwind speed of less than 20 knots (20 kt), the first threshold speed Vseuiii is equal to 5 kt and the second threshold speed Vseuil2 is equal to 7 kt. For a headwind with a speed of between 20 kt and 40 kt, the first threshold speed Vseuiii is equal to 8 kt and the second threshold speed Vseuil2 is equal to 10 kt. In addition, if the lateral speed Vy of the aircraft is less than or equal to 20 kt, no multiplying coefficient is applied to the threshold velocities Vseuiii and Vseuil2. On the other hand, if this lateral velocity Vy of the aircraft is greater than 20 kt, a multiplying coefficient can be applied to the threshold velocities Vseuill and Vseuil2. This multiplier coefficient may for example be equal to 1.5 when the lateral speed Vy reaches 40 kt.
[0017] The flight control method according to the invention is engaged by pilot action on an activation means, for example by a simple support or a double press on a dedicated button. Furthermore, a pilot may need to manually adjust this trajectory Ts., Both during a cruise flight and a low-altitude flight in order to get closer to its objectives depending on the environment and / or climatic conditions. In particular during a visual flight and at low altitude, the pilot can adjust this trajectory Ts01 to fly near buildings or reliefs being for example subjected to a strong wind, such as a side wind, which can influence on the maneuvers of the aircraft. Advantageously, the flight control method according to the invention enables the pilot to act directly and independently on the parameters characterizing the trajectory Ts01 by transparency via control elements in order to modify these parameters characterizing the trajectory Ts01. In this way, during this first operating mode of the control members and the autopilot, it is possible to control by transparency the parameters of the trajectory Ts01 according to the first type of characterization of this trajectory Ts01 so that said aircraft follows a new trajectory. Tsoln. It is thus possible to control, by transparency, a change in the forward speed Va, independently of the ground road angle TKsol and of the slope P or of the vertical speed Wz, if necessary, by a first action with respect to a first axis A of mobility of a control member and via the autopilot. Similarly, it is possible to control, by transparency, a modification of the ground road angle TKsol, independently of the forward speed Va and the slope P or of the vertical speed Wz, if appropriate, by a second action with respect to a second axis B of mobility of a control member and through said autopilot and a modification of the slope P or the vertical speed Wz if necessary, regardless of the forward speed Va and the ground road angle TKsni, by a third action with respect to a third axis C of mobility of a control member and via said autopilot. Thus, an action on a control member with respect to at least three of the mobility axes A, B, C, D makes it possible, by means of the autopilot which acts on the different flight parameters, to modify respectively and independently the forward speed Va, the ground road angle TKs01 and the slope P, or the vertical speed Wz, if any, of the path Ts01. Such action with respect to one of these mobility axes A, B, C then modifies the flight instructions supplied to the autopilot which generates control commands in order to carry out the pilot's request. For this purpose, the autopilot can act on one or more flight parameters of the aircraft, such as the collective and cyclic pitch of the main blades of a main rotor, the collective pitch of the secondary blades of a tail rotor, or else at least one propellant propeller or the displacements of the moving parts of the aerodynamic elements possibly present on the aircraft, in order to obtain this modification of a single parameter of the trajectory Tsni according to the first type of characterization. Following each pilot action on at least one control member with respect to the mobility axes A, B, C, D, the aircraft evolves according to a new path Tsoln, characterized, according to the first type of characterization, by a new angle TKsoln ground road, a new forward speed Van, a new slope or a new vertical speed Wzn if any, and / or a new heading tone. In fact, the flight instructions of the autopilot are aligned, during this first operating mode of the control members and the autopilot and during each action of the pilot on a control member, on the parameters of the new trajectory. Tsoln. By flight instruction alignment is meant the parameters of the new Tsoln trajectory the fact that the initial flight instructions are modified to take values corresponding to this new trajectory Tsoln, these flight instructions then being the new ground angle TKsoln, the new forward speed Van, the new slope Pn, or the new vertical speed Wzn if necessary, and / or the new course tpn so that the aircraft follows through the autopilot this new trajectory Tsoln. Thus, the flight control method according to the invention enables the pilot to modify the trajectory Ts., Followed by the aircraft by acting directly on the parameters of the trajectory Tsol in course of flight according to the first type of characterization and to allow autopilot to automatically follow the new trajectory Tsoln chosen by the pilot. In addition, an action of the pilot with respect to a fourth mobility axis D of a control member also makes it possible to modify a parameter of the trajectory Tsol of the aircraft. For example, the cap tp may be modified by an action with respect to this fourth axis of mobility D. Moreover, this cap tp may be modified directly by the pilot of the aircraft by an action on the pedals traditionally present on a aircraft. In addition, this cap 4m has no effect on the trajectory Tsol followed by the aircraft and, consequently, on the direction of advancement of the aircraft as part of this first mode of operation in uniform. trajectory, the direction of the trajectory Ts01 being defined by the ground road angle TKsot. Consequently, an action of the pilot with respect to a fourth mobility axis D of a control member may make it possible to modify another parameter of this trajectory Ts, of the aircraft. Preferably, an action of the pilot with respect to this fourth mobility axis D makes it possible to modify the ground road angle TKsol, the pilot thus having two possibilities to modify this ground road angle TKsol by means of two axes of mobility B, D.
[0018] As a result, the flight instructions of the autopilot are aligned on the parameter of the trajectory Ts.1 which has been modified by this action of the pilot on a control member with respect to this fourth mobility axis D so that the aircraft follows via the autopilot the new trajectory Tsoln.
[0019] Advantageously, the use of these two axes of mobility B, D to act on the sole ground TKsol road angle allows the pilot to give it more flexibility to modify this TKsol ground road angle for example by one or the other. other of these hands and thus facilitate the sequence of maneuvers and / or modifications of these parameters of the trajectory Tsol of the aircraft. However, the course y can be changed without direct action of the pilot on this course y when the driver acts on a controller to change the ground road angle TKsoi or the forward speed Va.
[0020] For example, during particular flight conditions, especially in strong winds, certain limit angles between the longitudinal direction X and the Tsol trajectory can lead to an uncomfortable flight for the occupants or even dangerous. In particular, an alignment of the longitudinal direction X of the aircraft and its trajectory Ts01 in case of strong lateral wind can lead to such a flight. In fact, in these particular flight conditions, the course y can be modified by the autopilot during variations of the ground road angle TKs01 or of the forward speed Va in order to avoid reaching such speeds. limit angles. As a result, the flight instructions of the autopilot are aligned with the parameter of the trajectory Ts01 that has been modified by this action of the pilot, that is to say the new ground angle TKsnin 10 or the new speed of Van advance and the new cap yin so that the aircraft follows through the autopilot the new trajectory Ts0In obtained. Likewise, a modification of the heading y controlled by the pilot, for example by transparency via a rudder of the aircraft, may lead to a modification of the ground road angle TKs01 by the autopilot in order to avoid reaching these limits. Here again, the flight instructions of the autopilot are aligned with the new heading tpn of the new trajectory Ts0In and possibly with the new ground road angle TKsoln so that the aircraft tracks, via the autopilot, the new trajectory Tsoln obtained. . Of course, the pilot can also, according to this second mode of operation, act simultaneously on several mobility axes A, B, C, D, the autopilot generating control commands in order to modify the parameters of the Tscii trajectory requested by the pilot without modifying the other parameters of this trajectory Ts01.
[0021] Furthermore, during the second operating mode of the control members and the autopilot, the parameters of the trajectory Ts0 can be controlled independently and by transparency, according to the second type of characterization of this trajectory Ts01 so that said aircraft follows a new Tsoln trajectory. It is thus possible to control by transparency a modification of the longitudinal speed Ux by a first action with respect to a first axis A of mobility of a control member and via the automatic pilot. Similarly, it is possible to control by transparency a modification of the lateral speed Vy by a second action with respect to a second axis B of mobility of a control member and by means of said autopilot as well as a modification of the speed vertical Wz by a third action with respect to a third axis C mobility of a control member and through said autopilot. In addition, a pilot action with respect to a fourth mobility axis D of a control member makes it possible to modify the heading tp of the aircraft which has a direct effect on the direction of advance of the aircraft in the case of course keeping, contrary to the course keeping. Indeed, the directions X, Y, Z and, consequently, the longitudinal velocities Ux, lateral Vy and vertical Wz are related to the aircraft. In fact, with each modification of the heading y, these directions X, Y, Z are modified vis-à-vis a terrestrial reference and, consequently, the directions of longitudinal speeds Ux, lateral Vy and vertical Wz also change. Thus, an action on a control member with respect to the mobility axes A, B, C, D makes it possible, by means of the automatic pilot 30 which acts on the various flight parameters, to modify the longitudinal speeds Ux respectively and independently. , lateral Vy and vertical Wz as well as the cap t. Such action with respect to one of these mobility axes A, B, C, D then modifies the flight instructions supplied to the autopilot, which generates control commands in order to carry out the pilot's request. Following each pilot action on at least one control member with respect to the mobility axes A, B, C, D, the aircraft evolves according to a new trajectory Tsoln, characterized, according to the second type of characterization, by new speeds. longitudinal Uxn, lateral Vyn and vertical Wz, and / or a new cap gin. In fact, the flight instructions of the autopilot can be aligned, during this second operating mode of the control members and the autopilot and during each action of the pilot on a control member, on the parameters of the new trajectory Tsoln, that is to say the new longitudinal velocities Uxn, lateral Vyn and vertical Wzn and / or the new heading tpn so that the aircraft follows through the autopilot this new trajectory Tsoln.
[0022] However, a systematic synchronization of the flight instructions of the autopilot on the new longitudinal velocities Uxn, lateral Vyn and vertical Wzn following a pilot action on at least one control member with respect to the mobility axes A, B, C, D can lead to a dangerous flight situation depending on the environment in which the aircraft is, especially when the aircraft is moving near buildings or relief. In fact, different synchronization conditions can be taken into account to perform this synchronization of the flight instructions of the autopilot.
[0023] According to first synchronization conditions, these flight instructions are aligned respectively and independently on the new longitudinal velocities Uxn and lateral Vyn if this new longitudinal velocity Uxn is greater than a fourth threshold velocity Vseuig and if this new lateral velocity Vyn has an absolute value less than a fifth threshold speed Vseuil5- In this case, the fourth threshold speed Vseuii4 is for example equal to 0 kt, while avoiding one of the flight instructions is a longitudinal speed Ux negative causing a displacement of the aircraft to the back, that is to say with a significantly reduced visibility. This fourth threshold speed Vseulla may also be equal to -10 kt, thus avoiding that one of the flight instructions is a too long negative longitudinal speed Ux resulting in a rapid movement of the aircraft towards the rear. Similarly, the new lateral speed Vyn becomes one of the flight instructions if it does not generate a lateral displacement of the aircraft too fast. The fifth threshold speed Vseuil5 is for example equal to 45 kt. According to second synchronization conditions, these flight instructions are respectively aligned and independently on the new longitudinal speed Uxn if this new longitudinal speed Uxn is greater than a fourth threshold speed Vseuil4 and on the new lateral speed Vyn after a specific action of a pilot of the aircraft. This action of the pilot is for example the pressing of a synchronization button of the new lateral speed Vy of the aircraft. According to these second synchronization conditions, the pilot chooses whether the new lateral speed Vyn must be one of the flight instructions. On the other hand, whatever the synchronization conditions, if the new longitudinal velocity Uxn is lower than a fourth threshold velocity Vseuig, the flight instruction corresponding to the longitudinal velocity Ux is aligned with this fourth threshold velocity VseuiI4. new lateral velocity Vyn has an absolute value greater than the fifth threshold velocity VseuiI5, the flight instruction corresponding to the lateral velocity Vy is aligned with this fifth threshold velocity Vseui15. The flight instruction corresponding to the vertical speed Wz of the aircraft is generally zero in the case of a heading flight. Indeed, such a flight is generally held at low altitude and the aircraft operates in such an environment in automatic flight with a constant altitude relative to the ground, that is to say with a vertical speed Wz zero. In fact, after an action by the pilot which has generated a modification of this vertical speed Wz, this flight instruction corresponding to the vertical speed Wz remains generally unchanged and therefore zero. However, if this action of the pilot causes the aircraft to evolve with a new vertical speed Wzn significant and greater than a sixth threshold speed Vseuil6 and the pilot does not reduce this new vertical speed Wzn, we can deduce 20 the wish of the pilot to evolve now with this new vertical speed Wzn. In this case, these flight instructions can be aligned with the new vertical speed Wzn which is greater than the sixth threshold speed Vseuil6. For example, the sixth threshold speed Vseuil6 is 500 feet per minute (500ft / min). On the other hand, when the new vertical speed Wzn of the aircraft is negative, the flight instruction corresponding to this vertical speed Wz can remain zero, in particular in order to avoid the risk of a loss of lift of the main rotor of the aircraft in 30 through a mass of air previously stirred by the main rotor. However, this risk of loss of lift occurring for vertical speeds Wz less than -500 ft / min, the flight instruction corresponding to the vertical speed Wz of the aircraft can be aligned with the new vertical speed Wzn when this new vertical speed Wzn is in a range of negative vertical speeds Wz greater than or equal to -500ft / min. For example, this range of vertical speeds Wz has a lower limit of -500 ft / min and an upper limit of -300 ft / min.
[0024] Furthermore, manually maintaining an aircraft at zero speed, whether it is the longitudinal speed Ux, the lateral speed Vy and / or the vertical speed Wz, requires a workload of the driver all the higher. the external conditions are unfavorable, such as poor visibility or the presence of turbulence, for example. These external conditions can go so far as to make this task impossible, for example in the event of complete loss of visibility due to the presence of a cloud of sand, dust or snow raised by the blast of the main rotor.
[0025] In fact, it can be considered that, if an absolute value of the new longitudinal speed Uxn and / or the new lateral speed Vyn is low and lower than a seventh threshold speed VseuiI7, the pilot wishes to maintain this new speed zero and the setpoint of corresponding flight must be void. This seventh threshold speed Vseut17 is for example equal to 1 kt. For example, when the longitudinal velocity Ux and lateral velocity Vy are lower than this seventh threshold velocity Vseu117, the aircraft is in a flight situation close to a hover, the flight control system then makes it possible to hold a fixed position by ground ratio.
[0026] On the other hand, autopilot flight instructions are always aligned with the new heading tpn. Thus, the flight control method according to the invention allows the pilot to modify the trajectory Ts01 followed by the aircraft by acting directly on the parameters of the trajectory Ts01 in course of course according to the second type of characterization and to allow the pilot automatically follow the new Tsoln trajectory chosen by the pilot. Of course, the pilot can also, according to this second mode of operation, act simultaneously on several mobility axes A, B, C, D, the autopilot generating control commands in order to modify the parameters of the trajectory Ts01 requested by the pilot without modifying the other parameters of this trajectory Ts.1.
[0027] Advantageously, the flight control method according to the invention thus makes it possible to ensure, according to the longitudinal speed Ux of the aircraft, an automatic flight allowing steering by transparency according to a trajectory or course. Whatever the mode of operation of the control members and the autopilot, the first and second control levers may be used as respectively the first and second control members, the first control member then having the first axis A of mobility and the second mobility axis B, the second control member having the third mobility axis C. These first and second levers thus make it possible to steer the aircraft in trajectory keeping according to the trajectory or to fly in accordance with the method according to the invention and via the autopilot.
[0028] However, such a particular use of the control levers is not suitable for a sudden maneuver of the aircraft in order, for example, to avoid an obstacle located on the trajectory Ts01 of the aircraft or close to it. Indeed, the first and second control levers do not allow in this particular use to quickly achieve a vertical or lateral displacement of the aircraft. A sudden obstacle avoidance maneuver is generally performed only by rotating about the pitch axis, i.e., through the first control lever to effect vertical movement. But this maneuver around the pitch axis, obtained by a variation of longitudinal cyclic pitch, may be accompanied by an action of the pilot on the second control lever thus also causing a variation of the collective pitch. In fact, a sudden action of the pilot on at least one of the first and second control levers, and preferably only the first control lever, causes a deactivation of the holding of the setpoint of the slope P or the vertical speed Wz if necessary via the autopilot in course of flight. In this way, the pilot can control the longitudinal cyclic pitch to act on the aircraft in rotation about the pitch axis and possibly the collective pitch to act on the aircraft in translation in the direction of elevation Z and thus perform the necessary avoidance maneuver. However, during flight phases close to a hover, it is not necessary to identify a sudden action of the pilot on one of the control levers. Indeed, the assignment of the actions to the first and second control levers is unambiguous, a longitudinal action on the first control lever essentially affecting the longitudinal speed of the aircraft and an action on the second control lever essentially affects its speed. vertical. The pilot can then perform an avoidance maneuver if necessary. For example, following the detection of such a sudden action of the pilot and switching to a mode of operation of transparency control, this pilot can control by transparency the pitch of the aircraft through the first control lever to cause rotational movements of the aircraft around the transverse direction Y. The slope P is then no longer considered as a flight instruction in course of flight and therefore not controlled by the autopilot so as not to to oppose the avoidance maneuver. In addition, the collective pitch remains constant except action by transparency of the pilot on the second control lever to cause translational movements of the aircraft in the direction of elevation Z. By brutal action is meant a large amplitude action pilot of the aircraft on one of the two control levers. Indeed, such a large-amplitude action can be considered as a request to avoid an obstacle on the part of the pilot, steering or trajectory control being carried out by movements of small amplitude so to obtain modifications of the trajectory Tsol. Moreover, the flight control system according to the invention may comprise control members dedicated to steering by transparency of the aircraft in course of course or in course keeping according to the trajectory Tsol by means of the method according to the invention. the invention and the autopilot. The flight control system according to the invention may for example comprise a first control member positioned on the first control lever and a second control member positioned on the second control lever. The first control member comprises the first mobility axis A and the second mobility axis B while the second control member comprises the third mobility axis C and optionally the fourth mobility axis D. The flight control system thus comprises two control members jointly forming at least three mobility axes A, B, C or even four mobility axes A, B, C, D. A first control member is provided with two mobility axes A, B and a second control member is provided with one or two mobility axes C, D. Such control members are generally calibrated and thus control movements of the aircraft accurate and predetermined. Thus, regardless of the operating mode of the control members and the autopilot, when the pilot acts on one of the control members by exerting a pulse or a long support with respect to a mobility axis A, B, C, D, a variation of one of the parameters of the trajectory Ts01 by a predetermined value is carried out. Such control devices are often referred to by the English language term "beeps". For example, it is considered that there is a long press on a control member as soon as this support is maintained for a period of at least one second (1 s). A pulse on this control member then corresponds to a support for a shorter time. For example, when the aircraft is moving in course of flight, during a long press on a control member relative to the mobility axis A, the aircraft accelerates or decelerates by 1.5 knots per second (1.5 kt / s). ) on the Tsol trajectory as long as this long support is maintained. Then, when this control member is released by the pilot relative to the mobility axis A, the autopilot aligns these flight instructions on the new forward speed Van of the aircraft, stabilizing this new forward speed. Van of the aircraft by canceling the acceleration or deceleration present at the moment the pilot releases this long support on the control member. Similarly, during a long press on a control member with respect to the mobility axis B or D, the ground plane angle TKsol of the aircraft varies at the rate of typically 3 degrees per second (3). ° / s) as long as this long support is maintained. Then, when this control member is released by the pilot relative to the mobility axis B or D, the autopilot aligns these flight instructions on the new taxi ground angle TKsnin of the aircraft to follow a new trajectory Tsoi .
[0029] Finally, following an impulse on a control member with respect to the mobility axis C, the slope P of the aircraft varies by a value of 0.1% of slope with each pulse and this slope P varies with a speed of 0.3% of slope per second (0.3% / s) during a long press on this control member as long as this long support is maintained. Then, following each pulse or when this control member is released by the pilot relative to the mobility axis C, the autopilot aligns these flight instructions on the new slope Pn of the aircraft to follow a new trajectory TS01.
[0030] In addition, the rate of variation of the slope P may also be variable in order to take account, for example, of an objective altitude or an objective stopping point of the aircraft. Moreover, a variation of the slope P modifies this objective altitude or this objective stopping point and, consequently, the distance up to this objective altitude or this objective stopping point. The rate of variation of the slope P is, for example, proportional to the inverse of the square of the speed of advance of the aircraft for significant forward speeds. However, below a third threshold speed VseuiI3, the evolution of the aircraft according to a slope P having no direction, the piloting of the aircraft can be carried out according to flight instructions including a speed reference vertical Wz. Therefore, an action on a control member with respect to the mobility axis C changes the vertical speed Wz of the aircraft. In fact, during a long press on a control member with respect to the mobility axis C, the aircraft flying at a forward speed below this third threshold speed Vseu03, the aircraft accelerates or decelerates vertically. for example 150 feet per minute (150 ft / min) as long as this long support is maintained. Then, when this control member is released by the pilot relative to the mobility axis C, the autopilot generally aligns these flight instructions on the new vertical speed Wz. On the other hand, when the aircraft is operating according to the second mode of operation of the control members and the autopilot of the method according to the invention, the effects of these control members may be different. Indeed, when the aircraft evolves in heading behavior, during a long press on a control member relative to the mobility axis A, the aircraft accelerates or decelerates longitudinally typically 1.5 kt / s as long as this long support is maintained. Then, when this control member is released by the pilot relative to the mobility axis A, the autopilot aligns these flight instructions on the new longitudinal speed Uxn of the aircraft. Similarly, during a long press on a control member 30 relative to the mobility axis B, the aircraft accelerates or decelerates laterally typically 1.5 kt / s as long as this support is maintained. Then, when this control member is released by the pilot relative to the mobility axis B, the autopilot aligns these flight instructions on the new lateral speed Vy of the aircraft according to the first or second synchronization conditions. In addition, during a long press on a control member relative to the mobility axis C, the aircraft accelerates or decelerates vertically 150 feet per minute (150 ft / min) as long as this support is maintained. Then, when this control member is released by the pilot with respect to the mobility axis C, the autopilot generally keeps unchanged the initial flight instructions corresponding to the vertical speed Wz, that is to say a zero value. thus ensuring altitude hold.
[0031] Furthermore, during a long press on a control member relative to the mobility axis D, the aircraft rotates about its yaw axis with an angular velocity of 3 degrees per second (3 ° / s). If this long support is maintained for more than three seconds, the aircraft then rotates around its yaw axis with an angular speed of 10 ° / s as long as this support is maintained. Then, when this control member is released by the pilot relative to the mobility axis D, the autopilot aligns these flight instructions on the new heading tp of the aircraft. In addition, when the aircraft is hovering, a pulse on a control member relative to the mobility axis A causes a longitudinal displacement of the aircraft of 1 meter (1 m). Similarly, a pulse on a control member with respect to the mobility axis B causes a longitudinal displacement of the aircraft of 1 m and a pulse on a control member with respect to the mobility axis C causes a displacement vertical of the aircraft 1 foot (1 ft).
[0032] The flight instructions of the autopilot whether in course of keeping or heading are generally constant as the pilot does not act on a controller. However, these flight instructions can be variable in the context of a particular mode of operation of the method according to the invention and for the purpose of hovering the aircraft to a stop position S determined during the commitment of this particular mode of operation. During this particular mode of operation of the method according to the invention, the pilot can act on each control member with respect to the mobility axes A, B, C, D in order to modify at least one parameter of the trajectory Ts01. As a result, new flight instructions of the autopilot are aligned, which are also variable in order to achieve a stationary flight of the aircraft to a new stop position Sn determined from the stop position S determined during the engagement of this particular mode of operation and the actions of the pilot on the control organs. The stop position S as well as the new stop position Sn 20 can be displayed on a display means in order to inform the pilot thereof. The present invention also relates to a flight control system in course of flight or to a heading of a rotary wing aircraft, this flight control system comprising at least one control member, jointly provided with several axes. mobility A, B, C, D, and an autopilot generating control commands according to predefined modes of operation and according to flight instructions. The flight control system of the aircraft may also comprise a first control lever for modifying the cyclic pitch of the main blades of a main rotor of the aircraft and a second control lever for modifying the collective pitch of the aircraft. main blades of this main rotor. This first control lever comprises two axes of mobility and in particular makes it possible to control the rotational movements of the aircraft around the longitudinal X and transverse Y directions. The second control lever comprises a single mobility axis and in particular makes it possible to control movements. of translation of the aircraft in the direction of elevation Z.
[0033] The flight control system can thus implement the flight control method in course of keeping or heading behavior described above. The invention and its advantages will appear in more detail in the context of the description which follows with exemplary embodiments given by way of illustration with reference to the appended figures which represent: FIG. 1, an aircraft equipped with flight control according to FIG. FIG. 2 is a diagram showing the ground plane angle and the heading of the aircraft; FIGS. 3 and 4 are two detailed views of control levers of a rotary wing aircraft. The elements present in several separate figures are assigned a single reference.
[0034] In FIG. 1, an aircraft 10 is shown, this aircraft 10 comprising a main rotor 11 positioned above a fuselage 13 and an anti-torque rear rotor 12 positioned at the rear end of a tail boom 14. aircraft 10 also comprises a dashboard 5, a seat 20 on which can sit a pilot of the aircraft 10, an autopilot 15 and manual control means, consisting in particular of two control levers 21,22 and a rudder 23.
[0035] In addition, an X, Y, Z mark is attached to this aircraft 10, and more particularly to its center of gravity. The longitudinal direction X extends from the front of the aircraft 10 towards the rear of the aircraft 10, the elevation direction Z extends from bottom to top perpendicular to the longitudinal direction X, the transverse direction Y extending from right to left perpendicular to the longitudinal X and elevation Z directions. The longitudinal direction X is the roll axis of the aircraft 10, the transverse direction Y is its pitch axis and the elevation direction Z is its yaw axis.
[0036] The main rotor 11 has a substantially vertical axis of rotation, that is to say parallel to the elevation direction Z, and is provided with three main blades 111,112,113 whose collective and cyclic pitch are variable and controllable by the intermediate control levers 21,22 and the autopilot 15. Similarly, the rear rotor 12 has a substantially horizontal axis of rotation, that is to say parallel to the transverse direction Y, and is provided with four secondary blades 121,122,123,124 whose collective pitch is variable and controllable via the rudder 23 and the autopilot 15.
[0037] More precisely, the first control lever 21 is movable around the longitudinal and transverse directions X, Y and drives the cyclic pitch of the main blades 111, 112, 113 via a first drive kinematic chain 24. The second control lever 22 is as for him mobile around the transverse direction Y and pilot the collective pitch of the main blades 111,112,113 by means of a second kinematic control chain 25. In fact, an action on this first control lever 21 then makes it possible to control rotational movements of the aircraft 10 around the longitudinal X and transverse directions Y and an action on this second control lever then makes it possible to control the translational movements of the aircraft 10 in the direction of elevation Z. Similarly, the The rudder 23 drives the collective pitch of the secondary blades 121, 122, 123, 124 through a third drive kinematic chain 26. In fact, a tion on this rudder 23 then allows to control rotational movements of the aircraft 10 around its yaw axis. These drive kinematic chains 24,25,26 for actuating the different blades and can be for example 15 composed by fully mechanical links between the manual control means 21,22,23 and the blades. These drive kinematic chains 24,25,26 can also be composed by mechanical links associated with hydraulic means of action or electrical connections associated with such hydraulic means of action. In addition, the autopilot 15 makes it possible to control the collective and cyclic pitch of the main blades 111, 112, 113 as well as the collective pitch of the secondary blades 121, 122, 123, 124 by acting respectively on these control kinematic chains 24, 25, 26. In fact, the autopilot 15 then makes it possible to control the rotational movements of the aircraft 10 around the longitudinal X and transverse Y directions and the translation movements of the aircraft 10 in the Z elevation direction as well as the movements of the aircraft. rotation of the aircraft 10 about its yaw axis.
[0038] Figures 3 and 4 show in more detail the gripping area respectively of the first and second control levers 21,22. The gripping zone of each control lever 21, 22 comprises in particular a control member 31, 31 and a push button 33. Each control member 31, 32 is movable around two specific mobility axes A, B, C, D. A first control member 31 present on the first control lever 21 and shown in Figure 3 is movable around the two mobility axes A, B. Similarly, a second control member 32 present on the second control lever 22 and shown in Figure 4 is movable around the two mobility axes C, D. A flight control system 1 is formed by the manual control means 21,22,23, the control members 31,32, the push button 33, the autopilot 15 and the control kinematic chains 24,25,26 . The aircraft 10 can fly along a trajectory Ts01 with respect to the ground, this trajectory Ts01 being determined relative to the ground and defined in a terrestrial geographical reference, for example determined by the cardinal points and the direction of the Earth's gravity. A flight of an aircraft 10 along this trajectory Ts01 can be characterized according to two types of characterization by different parameters of this trajectory Tsol. According to a first type of characterization, a flight of an aircraft 10 according to the trajectory Ts., Is characterized by a ground road angle TKsol between the direction of the trajectory Tsol and the direction of the north in a horizontal plane of this geographical landmark. a forward speed Va of the aircraft 10, a slope 30 P formed by the angle between the longitudinal direction X of the aircraft 10 and the horizontal orientation of the terrestrial reference and a course y which is the angle formed by the projection in a horizontal plane of the terrestrial reference of the longitudinal direction X of the aircraft 10 and the north direction.
[0039] The forward speed Va of the aircraft 10 is the speed of the aircraft 10 along the direction of this trajectory Tsol, this speed being adjustable relative to the ground or relative to the air. According to a second type of characterization, a flight of an aircraft 10 according to the trajectory Ts., Is characterized by a longitudinal velocity Ux in the longitudinal direction X, a lateral velocity Vy in the transverse direction Y and a vertical velocity WZ in the direction elevation Z as well as by course tp. These longitudinal speeds Ux, lateral Vy and vertical Wz are respectively a component of the forward speed Va of the aircraft 10 according to the three preferred directions X, Y, Z of the aircraft 10. FIG. a horizontal plane of this terrestrial reference of a trajectory Ts.1. The longitudinal and transverse directions X, Y of the aircraft 10 are also represented as well as the directions N, W of a terrestrial geographical reference. The heading qi is thus represented between the longitudinal direction X of the aircraft 10 and the north N direction. The ground road angle TKsol is represented between the direction of the Tsol trajectory and the north N direction. It can be seen that the heading q.i is different from the ground road angle TKsoi. As a result, the nose and the tail beam 14 of the aircraft 10 being aligned in the longitudinal direction X are not aligned with the trajectory Ts01. Similarly, the forward speed Va is aligned with the trajectory Ts.1 and is not parallel to the longitudinal direction X. In addition, the longitudinal velocity Ux and lateral velocity Vy respectively are projections of the forward speed Va of the aircraft, and preferably the speed of advance of the aircraft relative to the ground, in the longitudinal X and transverse directions Y. The vertical speed Wz and the slope P are not shown in this FIG. 2, which is located in a horizontal plane of the terrestrial reference, and therefore perpendicular to the elevation direction Z. The aircraft 10 generally moves along a trajectory Ts., in order to reach a ground objective such as an airstrip. However, the pilot may need to modify one or more parameters of this trajectory Ts01, for example to slow down, to avoid an obstacle not listed in a database of the aircraft 10 or simply to change course. Such modifications are particularly necessary during a visual flight and at low altitude and according to the environment and / or climatic conditions.
[0040] However, according to the flight conditions of the aircraft 10 and in particular its longitudinal speed Ux, the maneuvers made by the pilot are different. Indeed, when the aircraft 10 is moving at a low longitudinal speed Ux, the piloting of the aircraft 10 is generally performed in course keeping, the pilot acting on the parameters of the trajectory Tso, according to the second type of characterization. In this case, the pilot directly controls the longitudinal velocity Ux, lateral Vy and vertical Wz as well as the cap LI, of the aircraft 10 in order, for example, to move at a very low longitudinal velocity Ux and at low altitude near buildings.
[0041] On the other hand, when the aircraft 10 is moving at a greater longitudinal speed Ux, the piloting of the aircraft 10 is generally carried out in course of flight, the pilot acting on the parameters of the trajectory Ts01 according to the first type of characterization. In this case, the pilot prefers to directly control the forward speed Va of the aircraft 10 according to the trajectory Ts01, in order to slow down or accelerate the aircraft 10, and the ground road angle TKsol, in order to modify this trajectory Ts01, as well as the slope P and possibly the cap tp.
[0042] However, the evolution of the aircraft 10 along a slope P only makes sense after a certain forward speed of the order of 20 knots (20 kt). In fact, when the forward speed Va of the aircraft 10 is lower than a third threshold speed Vseu13, but in the range of speed of a course of flight, the pilot of the aircraft 10 controls the vertical speed Wz of the aircraft 10 in replacement of the slope P. In fact, the flight instruction according to the slope P is replaced by a flight instruction according to the vertical speed Wz of the aircraft 10. A flight control method in course of flight or heading allows to switch according to the longitudinal velocity Ux of the aircraft 10 between a first operating mode of the control members 31,32 and the autopilot 15 according to the first type of characterization of the trajectory Ts01 and a second mode operating the control members 31,32 and the autopilot 15 according to the second type of characterization of the trajectory Ts01. This second mode of operation of the control members 31,32 and the autopilot 15 is thus used for low forward speeds Va, the first operating mode being used at higher forward speeds Va.
[0043] Thus, during this first mode of operation of the control members 31,32 and the autopilot 15, the automatic pilot 15 allows the aircraft 10 to perform a flight with a flight path with respect to the ground, the flight instructions the autopilot 15 being the ground road angle TKsol, the forward speed Va, the slope P or the vertical speed Wz if necessary and the heading tp. However, during this second mode of operation of the control members 31,32 and the autopilot 15, the autopilot 15 allows the aircraft 10 to perform a flight with a heading behavior, the flight instructions of the autopilot 15 being the longitudinal velocity Ux, the lateral velocity Vy, the vertical velocity Wz and the course tu. The flight control system 1 makes it possible to implement this flight control method in course of keeping or course keeping. This flight control method in course of keeping or course holding is engaged via the button 33, for example by a simple support or a double pilot support on the button 33. The switch between the first and the second mode of operation of the control members 31,32 and the autopilot 15 is with respect to a hysteresis threshold in Vseuill and Vseuit2 threshold speeds, the first threshold speed Vseuill being greater than the second threshold speed Vseuii2. In fact, the first operating mode of the control members 31,32 and the automatic pilot 15 is engaged as soon as the longitudinal speed Ux exceeds the first threshold speed Vseuill and remains engaged as long as the longitudinal speed Ux is greater than or equal to the second threshold speed Vseui12. Similarly, the second operating mode of the control members 31,32 and the automatic pilot 15 is engaged as soon as the longitudinal speed Ux becomes lower than the second threshold speed Vseuil2 and remains engaged as long as the longitudinal speed Ux is less than or equal to the first threshold speed Vseuill- The threshold speeds Vseuiti and Vseuil2 can be a function of the flight conditions of the aircraft 10, essentially of the speed and the direction of the wind as well as the lateral speed Vy of the aircraft 10. during these two modes of operation of the control members 31,32 and the autopilot 15, transparency control is possible in order to adjust the trajectory Ts01. Thus, the pilot can directly control a modification of one or more parameters of the path Tsol via control members 31, 32 and via the autopilot 15. This flight control method allows, at the during this first operating mode of the control members 31,32 and the autopilot 15, to ensure a Ts01 trajectory holding by changing the forward speed Va, the ground road angle TKsol, the slope P or well the vertical speed Wz if necessary and possibly the course y via the autopilot 15 which acts on the various flight parameters.
[0044] Similarly, this flight control method allows, during this second mode of operation of the control members 31,32 and the autopilot 15, to ensure a course of behavior by changing the longitudinal speed Ux, the lateral speed Vy , the vertical speed Wz and the heading tp via the autopilot 15 which acts on the various flight parameters. In fact, each action of the pilot on a member of the control members 31,32 with respect to a mobility axis A, B, C, D modifies, via the automatic pilot 15, one of the parameters of the trajectory Ts01.
[0045] Thus, in flight behavior, a pilot action on a member of the control members 31,32 with respect to the axis A, B, C of mobility respectively modifies the forward speed Va, the ground road angle TKsoi , the slope P or the vertical speed Wz if necessary. In addition, the ground road angle TKsol can also be modified by a pilot action on a member of the control members 31,32 with respect to the axis D of mobility. The course y may in turn be modified by a pilot action on the rudder 23. On the other hand, in course of course, a pilot action on a member of the control members 31,32 with respect to the axis A, B, C, D of mobility respectively modifies the longitudinal speed Ux, the lateral speed Vy, the vertical speed Wz and the course LIJ- Of course, the pilot can act simultaneously on one or both of the control members 31,32 and by report to several 15 axes of mobility A, B, C, D, in order to modify several parameters of the trajectory Ts01. The autopilot 15 takes into account the actions of the pilot on the control members 31,32, modifies his flight instructions according to these actions and then generates control commands in order to modify the pitch of the main rotor blades 111,112,113 of the main rotor 11 and possibly the pitch of the secondary blades 121,122,123,124 of the rear rotor 12. The aircraft 10 then follows a new trajectory Tsoln, one or more parameters have been modified as requested by the pilot, these modified parameters being the new flight instructions of the In fact, during each pilot action on one of the control members 31,32, new flight instructions of the autopilot 15 can be aligned with the parameters of the new Tsoln trajectory, that is to say a new ground angle TKsoin, a new forward speed Van, a new slope Pn or a new vertical speed Wzn if necessary and / or a new at the heading Ln during the first mode of operation of the control members 31,32 and the autopilot 15, and a new longitudinal speed Uxn, a new lateral speed Vyn, a new vertical speed Wzn and / or a new course yin during the second mode of operation of the control members 31,32 and the autopilot 15. However, in the course of heading maintenance, synchronization conditions can be taken into account to align these new flight instructions to avoid generating potentially dangerous flight situations for the aircraft 10 which generally operates at low altitudes and near buildings and terrain.
[0046] According to first synchronization conditions, these flight instructions are aligned respectively and independently on the new longitudinal velocities Uxr, and lateral Vyn if this new longitudinal velocity Uxn is greater than a fourth threshold velocity Vseuil4 and if this new lateral velocity Vyn has a value absolute lower than a fifth threshold speed Vseuii5- According to second synchronization conditions, these flight instructions are respectively aligned and independently on the new longitudinal speed Uxn if this new longitudinal speed Uxn is greater than a fourth threshold speed Vseuil4 and on the new speed lateral Vyn after a specific action of a pilot of the aircraft 10. This action of the pilot is for example the pressing of a synchronization button of the new lateral speed Vy of the aircraft 10. According to these second synchronization conditions, the pilot chooses whether the new lateral speed Vyn must be one of the flight instructions.
[0047] On the other hand, whatever the synchronization conditions, if the new longitudinal velocity Uxn is lower than a fourth threshold velocity Vseuita, the flight instruction corresponding to the longitudinal velocity Ux is aligned with this fourth threshold velocity Vseuila. Similarly, if the new lateral speed Vyn has an absolute value greater than the fifth threshold speed VseuiI5, the flight instruction corresponding to the lateral speed Vy is aligned with this fifth threshold speed Vseui15.
[0048] The flight instruction corresponding to the vertical speed Wz of the aircraft 10 is generally zero in the case of a heading flight. Indeed, such a flight is generally held at low altitude and the aircraft 10 evolves in such an environment in automatic flight with a constant altitude relative to the ground, that is to say with a vertical speed Wz zero. In fact, after a pilot action that has generated a change in this vertical speed Wz, this flight instruction corresponding to the vertical speed Wz remains generally unchanged and therefore zero. However, if this action of the pilot causes the aircraft 10 to evolve with a new vertical speed Wzn large and greater than a sixth threshold speed Vseuii6 and the pilot does not reduce this new vertical speed Wzn, we can deduce the wish of the pilot to evolve now with this new vertical speed Wzn. In this case, these flight instructions can be aligned with the new vertical speed Wzn which is greater than the sixth threshold speed Vseui16. On the other hand, when the new vertical speed Wzn of the aircraft is negative, the flight instruction corresponding to this vertical speed Wz can remain zero, in particular in order to avoid a dangerous flight situation for the aircraft 10 or be aligned with the new vertical speed Wzn when this new vertical speed Wzn is within a range of vertical speeds Wz negative greater than or equal to -500 ft / min. Moreover, if an absolute value of the new longitudinal speed Ux and / or the new lateral speed Vy is low and lower than a seventh threshold speed VseuiI7, the pilot wishes to maintain this new speed zero and the corresponding flight instruction must be zero. . On the other hand, the flight instructions of the autopilot are always aligned with the new heading Ln. In addition, the first control lever 21 can be used as the first control member 31 and the second control lever 22 is used as the second control member 32. However, such particular use of the control levers 21 , 22 is not adapted to urgently perform a sudden maneuver of the aircraft 10 in order, for example, to avoid an obstacle in the path Ts01 or close to it. Indeed, the first and second control levers 21,22 20 then do not allow to quickly achieve a vertical or lateral displacement of the aircraft 10. In fact, holding the setpoint of the slope P or the vertical speed Wz if appropriate via the autopilot 15 is deactivated as soon as a sudden action of the pilot 25 on the first control lever 21 is detected. As a result, the pilot can control the longitudinal cyclic pitch in order to act on the aircraft in rotation about the pitch axis and possibly the collective pitch in order to act on the aircraft in translation according to the invention. 1 7 55 direction of elevation Z and thus perform the necessary avoidance maneuver. The flight instructions of the autopilot 15 whether in course of flight or in heading are generally constant as long as the pilot does not act on a control member 31,32. However, these flight instructions can be variable in the context of a particular mode of operation of the course or course keeping method, with the aim of hovering the aircraft 10 to a position 10 of S stop determined during the engagement of this particular mode of operation. During this particular mode of operation, the pilot can act on each control member 31,32 with respect to the mobility axes A, B, C, D in order to modify at least one parameter 15 of the trajectory Ts01. As a result, new flight instructions of the autopilot are aligned, which are also variable in order to hover the aircraft 10 to a new stop position Sn determined from the stop position S determined during the engagement of this particular mode of operation and the actions of the pilot on the control members 31,32. Naturally, the present invention is subject to many variations as to its implementation. Although several embodiments have been described, it is well understood that it is not conceivable to exhaustively identify all possible modes. It is of course conceivable to replace a means described by equivalent means without departing from the scope of the present invention. In particular, the aircraft 10 equipped with this flight control system 30 is not limited to the aircraft 10 shown in FIG.
[0049] This aircraft 10 may for example have two main rotors or be a hybrid helicopter. In addition, the number of main blades 111,112,113 of a main rotor 11 and the number of secondary blades 121,122,123,124 of a rear rotor 12 are not limited to the example of aircraft 10 shown in FIG. 11 or a rear rotor 12 may indeed have two, three, four, five blades or more than five blades.

权利要求:
Claims (18)
[0001]
REVENDICATIONS1. A flight control method for a rotary wing aircraft (10), said aircraft (10) following a trajectory Ts01 with respect to the ground with a forward speed Va, a longitudinal direction X extending from the rear of said aircraft ( 10) towards the front of said aircraft (10), a direction of elevation Z extending from bottom to top perpendicular to said longitudinal direction X and a transverse direction Y extending from left to right perpendicular to said longitudinal directions X and d elevation Z, said aircraft (10) comprising: - at least one rotary wing (11) provided with several main blades (111, 112, 111) whose collective pitch and cyclic pitch are variable about a pitch axis, said aircraft (10 ) being able to perform rotational movements about said X, Y, Z directions and translation along said X, Y, Z directions; - an automatic pilot (15) generating control commands according to predefined modes of operation; and flight instructions, said control commands being able to cause said movements of said aircraft (10) in rotation and / or in translation with respect to said directions X, Y, Z, and - a flight control system (10) comprising at least one control member (31,32) jointly provided with several mobility axes A, B, C, D, characterized in that - a first operating mode of said control members (31,32) and said pilot is applied automatically (15) when the longitudinal speed Ux of said aircraft (10) is greater than a first threshold speed Vseuill, said longitudinal speed Ux being a projection of said forward speed Va on said longitudinal direction X, said automatic pilot (15) then said aircraft (10) making a flight with a course of flight relative to the ground, said flight instructions of said autopilot (15) being a ground road angle TKsol, said forward speed Va, a slope P and u n cap y, and - a second mode of operation of said control members (31,32) and said autopilot (15) when said longitudinal speed Ux is lower than a second threshold speed VseuiI2, said autopilot (15) allowing then said aircraft (10) to perform a flight with heading behavior, the flight instructions of said autopilot (15) being said longitudinal velocity Ux, a lateral velocity VY, a vertical velocity Wz and said heading
[0002]
2. A flight control method for a rotary wing aircraft (10) according to claim 1, characterized in that - said first mode of operation of said control members (31,32) and said autopilot (15) remains engaged so much said longitudinal velocity Ux is greater than or equal to said second threshold velocity Vseu112, and - said second operating mode of said control members (31,32) and said autopilot (15) remains engaged as long as said longitudinal velocity Ux is lower or equal to said first threshold speed Vseuiii.
[0003]
3. Flight control method for rotary wing aircraft (10) according to any one of claims 1 to 2, characterized in that during said first mode of operation of said control members (31,32) and said pilot automatic (15), - it is possible to control by transparency, so that said aircraft (10) follows a new path Tsoin, a modification of: o said forward speed Va by a first action with respect to a first axis A mobility d a control member (31,32) and via said automatic pilot (15), o said ground road angle TKsol by a second action with respect to a second axis B of mobility of a control member (31). , 32) and via said autopilot (15), and / or o said slope P by a third action with respect to a third axis C of mobility of a control member (31,32) and by intermediate of said autopilot (15), and - said flight instructions of said pilot e automatic (15) on the parameters of said new trajectory Tsoln, said flight instructions being a new ground TKsoi road angle, a new forward speed Van, a new slope Pn and / or a new course L in order to follow by via said autopilot (15) said new Tsoln trajectory.
[0004]
4. A flight control method for a rotary wing aircraft (10) according to claim 3, characterized in that during said first mode of operation of said control members (31,32) and said autopilot, - one controls by transparency, so that said aircraft (10) follows a new path Tsoln, a modification of said ground road angle TKsol with respect to the ground by a fourth action 30 with respect to a fourth axis D of mobility of a control member (31, 32) and via said autopilot (15) and - said flight instructions said autopilot (15) on the parameters of said new trajectory Tsoln on a new ground TKsoln road angle in order to follow through said autopilot (15) said new trajectory Tsoln.
[0005]
5. A flight control method for a rotary wing aircraft (10) according to any one of claims 1 to 4, characterized in that during said second mode of operation of said control members (31,32) and said pilot automatic control (15), - it is controlled independently and by transparency, so that said aircraft (10) follows a new path Tsoin, a modification of: o said longitudinal speed Ux by a first action with respect to a first axis A mobility of a control member (31,32) and via said automatic pilot (15), o said lateral speed Vy by a second action with respect to a second axis B of mobility of a control member (31,32) and through said autopilot (15), and / or o said vertical speed Wz by a third action with respect to a third axis C of mobility of a control member (31, 32) and via said autopilot (15), and - one aligns said cons flights of said autopilot (15) on: o a new longitudinal velocity Uxn of said aircraft (10) if said new longitudinal velocity Ux ,, is greater than a fourth threshold velocity Vseut14 and o a new lateral velocity Vyn of said aircraft (10) if an absolute value of said new lateral speed Vyn is less than a fifth threshold speed Vseuii5.
[0006]
6. A flight control method for a rotary wing aircraft (10) according to any one of claims 1 to 4, characterized in that during said second mode of operation of said control members (31, 32) and said autopilot (15), - it is controlled independently and by transparency, so that said aircraft (10) follows a new path Tsoln, a modification of: 15 o said longitudinal speed Ux by a first action with respect to a first axis A mobility a member of the intermediate of said pilot control (31,32) and automatic (15), o said lateral speed Vy by a second action with respect to a second axis B of mobility of a control member (31). 32) and via said autopilot (15) and / or o said vertical speed Wz by a third action with respect to a third axis C of mobility of a control member (31, 32) and by via said autopilot (15), and - aligning the said flight instructions of said autopilot (15) on: o a new longitudinal velocity Uxn of said aircraft (10) if said new longitudinal velocity Uxn is greater than a fourth threshold velocity Vseu114 eto a new lateral velocity Vyn of said aircraft (10) after a specific action of a pilot of said aircraft (10).
[0007]
7. Flight control flight method for rotary wing aircraft (10) according to any one of claims 5 to 6, characterized in that during said second mode of operation of said control members (31,32) and said pilot automatically (15), said flight instructions of said autopilot (15) are aligned on a new vertical speed Wzn of said aircraft (10) if an absolute value of said new vertical speed Wzn is greater than a sixth threshold velocity Vseui16.
[0008]
8. A flight control method for a rotary wing aircraft (10) according to any one of claims 5 to 7, characterized in that during said second mode of operation of said control members (31,32) and said pilot automatic, - is controlled by transparency a change of course y by a fourth action with respect to a fourth axis D of mobility of a control member (31,32) and through said autopilot (15) independently of said speeds Ux, Vy, Wz and - said flight instruction of said autopilot (15) corresponding to said heading tp said aircraft (10) on a new cap wn.
[0009]
9. A flight control method for a rotary wing aircraft (10) according to any one of claims 5 to 8, characterized in that - if an absolute value of said new longitudinal speed U x n is less than a seventh threshold speed VseuiI7 , said flight record corresponding to said longitudinal velocity Ux is zero and - if an absolute value of said new lateral velocity Vy is lower than said seventh threshold velocity VseuiI7, said flight instruction corresponding to said lateral velocity Uy is zero.
[0010]
10. A flight control method for a rotary wing aircraft (10) according to any one of claims 3 to 9, characterized in that said aircraft comprising on the one hand a first control lever (21) for controlling rotational movements of said aircraft (10) about said longitudinal X and transverse directions Y and secondly a second control lever (22) for controlling translational movements of said aircraft (10) in said direction of elevation Z, - said first action is carried out with respect to said first mobility axis A and said second action with respect to said second mobility axis B via a first control member (31) which is said first control lever (21) and said third action is carried out with respect to said third mobility axis C and said fourth action with respect to said fourth mobility axis D via a second control member (32) which is st said second control lever (22).
[0011]
11. Flight control flight method for rotary wing aircraft (10) according to claim 10, characterized in that a sudden action on said first control lever (21) causes a deactivation of the holding of said setpoint of said slope P through said autopilot (15), said first control lever (21) then controlling rotational movements of said aircraft (10) about said longitudinal direction X and said second control lever (22) controlling translational movements said aircraft (10) in said elevation direction Z.
[0012]
12. A flight control method for a rotary wing aircraft (10) according to any one of claims 3 to 11, characterized in that said aircraft comprising on the one hand a first control lever (21) for controlling rotational movements of said aircraft (10) about said longitudinal X and transverse directions Y and secondly a second control lever (22) for controlling translational movements of said aircraft (10) in said direction of elevation Z said first action is carried out with respect to said first mobility axis A and said second action with respect to said second mobility axis B via a first control member (31) positioned on said first control lever ( 21) and said third action is effected with respect to said third mobility axis C via a second control member (32) positioned on said second control lever (22).
[0013]
13. A flight control method for a rotary wing aircraft (10) according to claim 12, characterized in that said fourth action is carried out with respect to said fourth mobility axis D via said second control member ( 32).
[0014]
14. A flight control method for a rotary wing aircraft (10) according to claim any one of claims 3 to 13, characterized in that said actions are carried out with respect to said axes A, B, C, D of mobility by means of controllers (31,32) calibrated and controlling precise movements of said aircraft (10).
[0015]
15. A flight control method for a rotary wing aircraft (10) according to any one of claims 1 to 14, characterized in that, if said forward speed Va is lower than a third threshold speed Vseui13, said slope P is replaced by said vertical speed W, as flight setpoint of said autopilot (15) during said first mode of operation of said control members (31,32) and said autopilot (15).
[0016]
16. A flight control method for a rotary wing aircraft (10) according to any one of claims 1 to 15, characterized in that said first and second threshold speeds Vseuill, VseuiI2 are a function of the longitudinal velocity of the relative wind undergone by said aircraft (10) as well as said lateral speed Vy.
[0017]
17. A flight control method for a rotary wing aircraft (10) according to any one of claims 1 to 16, characterized in that said flight instructions of said autopilot (15) may be variable in order to achieve a flight stationary of said aircraft (10) to a stop position S determined during the engagement of said hovering said aircraft (10).
[0018]
18. Flight control system (1) for a rotary wing aircraft (10), said aircraft (10) following a trajectory Ts., With respect to the ground with a forward speed Va, a longitudinal direction X extending from the rear of said aircraft (10) towards the front of said aircraft (10), a direction of elevation Z extending from bottom to top perpendicular to said longitudinal direction X and a transverse direction Y extending from left to right perpendicularly to said longitudinal directions X and elevation Z, - said aircraft (10) having at least one rotary wing (11) provided with several main blades (111,112,113) whose collective pitch and the cyclic pitch are variable around a pitch axis said aircraft (10) being capable of rotational movements about said X, Y, Z and translation directions along said X, Y, Z directions, said flight control system (1) having: o at least a control member (31,32) with a simultaneously with several mobility axes A, B, C, D, o an automatic pilot (15) generating control commands according to predefined modes of operation and according to flight instructions, said command commands being able to cause said movements of said aircraft (10) in rotation and / or in translation along said X, Y, Z directions, characterized in that said flight control system (1) implements the flight control method for rotary wing aircraft (10) according to any one of claims 1 to 17. -

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同族专利:

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公开号 | 公开日

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FR3023017B1|2016-06-10|

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CA2895080C|2017-10-03|

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EP2963517B1|2017-03-15|

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US20150375850A1|2015-12-31|

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CA2895080A1|2015-08-24|

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IL239605A|2018-02-28|

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US9789953B2|2017-10-17|

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EP2963517A1|2016-01-06|

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法律状态:
2015-05-26| PLFP| Fee payment|Year of fee payment: 2 |

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2016-01-01| PLSC| Search report ready|Effective date: 20160101 |

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2016-06-27| PLFP| Fee payment|Year of fee payment: 3 |

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2017-06-21| PLFP| Fee payment|Year of fee payment: 4 |

优先权:

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申请号 | 申请日 | 专利标题

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FR1401474A|FR3023017B1|2014-06-30|2014-06-30|SYSTEM AND METHOD FOR FLIGHT CONTROL OF AN AIRCRAFT WITH A ROTATING SAILING SYSTEM WHILE TAKING A TRAJECTORY OR HOLDING A CAP, ACCORDING TO ITS SPEED OF PROGRESS|FR1401474A| FR3023017B1|2014-06-30|2014-06-30|SYSTEM AND METHOD FOR FLIGHT CONTROL OF AN AIRCRAFT WITH A ROTATING SAILING SYSTEM WHILE TAKING A TRAJECTORY OR HOLDING A CAP, ACCORDING TO ITS SPEED OF PROGRESS|

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EP15172652.8A| EP2963517B1|2014-06-30|2015-06-18|A flight control system and method for a rotary wing aircraft, enabling it to maintain either track or heading depending on its forward speed|

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CA2895080A| CA2895080C|2014-06-30|2015-06-19|Flight control system and method in directional stability or heading mode in a rotary wing aircraft based on its forward speed|

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IL239605A| IL239605A|2014-06-30|2015-06-23|Flight control system and method for a rotary wing aircraft, enabling it to maintain either track or heading depending on its forward speed|

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US14/750,731| US9789953B2|2014-06-30|2015-06-25|Flight control system and method for a rotary wing aircraft, enabling it to maintain either track or heading depending on its forward speed|