• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The invention relates to a servo-control method of a power steering device (1) comprising an assistance motor (2) and a driving wheel (3), in the course of which a flying torque setpoint is generated. (T3_set), we measure the effective flywheel torque (T3_meas) which is actually exerted by the driver on the driving wheel (3), the difference, known as the "flywheel torque error" (ΔT3), is determined between the torque setpoint flywheel (T3_set) and the actual flywheel torque (T3_meas), and then generates a motor torque setpoint (T2_set) for the assistance motor (2), starting on the one hand with a first filtered proportional component (CPF), obtained by filtering by means of a phase advance filter (15) the flywheel torque error (ΔT3) weighted by a first assist gain (KP), and secondly by a second return component derivative (CD), obtained by calculating the time derivative of the actual flying torque (d (T3_meas) / dt) and weighting said derivative by a second derivative gain (KD).
    公开号:FR3037671A1
    申请号:FR1555640
    申请日:2015-06-19
    公开日:2016-12-23
    发明作者:Pascal Moulaire；Herve Peltier；Arnaud Thiery；Tahar Slama
    申请人:JTEKT Europe SAS；
    IPC主号:
    专利说明:

    [0001] BACKGROUND OF THE INVENTION The present invention relates to servo control methods for managing a power steering device. The present invention more particularly relates to a control method which uses the steering wheel torque, that is to say the torque exerted by the driver on the steering wheel, as a controlled variable. Processes are already known in which one defines, according to the dynamic situation of the vehicle (speed, lateral acceleration, etc.) and the configuration of the steering device (steering angle, angular speed of rotation of the steering wheel, etc.). ), a flying torque setpoint, which is compared to the measurement of the actual flying torque, actually exerted by the driver on the steering wheel at the moment considered, in order to then determine a motor torque setpoint that is applied an assistance motor for said assistance motor to act on the steering mechanism so that the actual flying torque, felt by the driver, follows said steering torque setpoint. Generally, the engine torque setpoint is obtained proportionally, by multiplying the difference between the flying torque setpoint (which may, in certain assistance configurations, be zero) and the actual flying torque, that is, tell the flying torque error, by a predetermined assistance gain. A first difficulty, when implementing such a servocontrol, 25 is the setting of the value of the assistance gain. Indeed, to ensure a comfortable handling, especially when the vehicle is stopped (for example when the driver makes a significant turn to leave a parking lot) or when the vehicle is traveling at low speed, so that the resistance that the steering mechanism, and more particularly the tires, oppose the steering maneuver is relatively high, it is preferable to provide a high assistance gain, which allows the assistance engine to deliver a high torque without the driver has to exert a significant torque on the steering wheel. However, to guarantee the stability of the control of the steering, and thus in particular to avoid the appearance of oscillations of the steering wheel, it is on the contrary necessary to limit the gain of assistance, that is to say to maintain said assist gain below 3037671 2 of a maximum allowable value which corresponds to a sufficient gain margin (in the sense of the Nyquist criterion). Moreover, the mechanical part of the steering device is subjected to various physical phenomena, in particular friction phenomena (dry and / or viscous) or inertial phenomena related to the mass of the various constituent members of said mechanical part (shaft of assistance engine, rack, steering wheel, wheels, etc.). However, these different phenomena can have adverse effects in terms of feeling at the wheel, that is to say, the way the driver perceives, through the steering wheel, the behavior of the direction, and therefore more generally how the driver intuitively feels and interprets the vehicle's behavior. In particular, the friction and the inertia may for example give the feeling that the steering does not react when a steering maneuver is started, that is to say when the driver starts to turn the steering wheel, giving This gives the driver an impression of heaviness and lack of responsiveness. Conversely, as soon as the driver reaches the steering wheel, sufficient effort to overcome the static dry friction, the steering can relax suddenly. This abrupt detachment effect (also called "stick slip") provides an unpleasant sensation of jerky driving. Such a sudden detachment effect is particularly noticeable during "zeroing out", that is to say when the driver begins to turn the steering wheel (to the left or right respectively) from a position angularly of substantially centered origin, so as to move the steering device from a zero steering angle, which typically corresponds to a straight line trajectory, to a non-zero steering angle, which corresponds to a curved trajectory, or during the steering reversals, that is to say when the driver reverses the direction of rotation of the steering wheel (to go from a right turn to a left turn, or vice versa). To limit such effects, it is conceivable to use, during the determination of the motor torque setpoint, a flywheel derivative return, that is to say a feedback branch which measures the actual flying torque, i.e. the value of the steering wheel torque actually exerted by the driver on the steering wheel, and calculates the time derivative of this actual steering torque, so as to allow the in consideration of this derivative, weighted by a derivative gain, during the development of the motor torque setpoint. However, the introduction of a derivative feedback in the servo control loop of the steering device can also be a source of instability. In particular, the assistance gain and the derivative gain both of which affect the overall stability conditions of the servo-control, these two parameters are in practice interdependent, so that the setting of the derivative gain can not be realized. only in a conditioned range and limited by the value of the assistance gain, and vice versa. In such a configuration, and in view of the need to maintain at any time a margin of gain sufficient to guarantee the stability of the servocontrol, it is therefore not possible, for example, to maximize the derivative gain and to take full advantage of benefit of the improvement of feeling provided by the action of the return of derivative, nor, conversely, of maximizing the gain of assistance to optimize the action of the engine of assistance and thus the efficiency and the comfort of the assistance during management maneuvers. The objects assigned to the invention therefore aim to improve the known power steering servo-control methods so as to be able to reconcile effective and powerful assistance, a faithful and comfortable feeling of steering behavior, as well as excellent stability. enslavement. The objects assigned to the invention are achieved by means of a servo-control method of a power steering device comprising an assistance motor and a driving wheel on which a driver can exercise a force, said "torque steering wheel, said method comprising a step (a) for defining a flying torque setpoint, during which a flying torque setpoint representative of a flying torque value that one wishes to reach is generated, a step (b) effective flywheel torque measurement, during which the value, called the "actual flying torque", of the steering wheel torque actually exerted by the driver on the steering wheel is measured, a step (c) of comparison with the 30 course of which is determined the difference, called "flywheel torque error", between the flywheel setpoint and the actual flywheel torque, a step (d) of torque torque setpoint determination during which one generates a a motor torque setpoint which is intended to be applied to the assist motor so that the assisting motor can act to reduce the flywheel torque error, said method being characterized in that, in the course of step (d) of determining the motor torque setpoint, the motor torque setpoint is generated from a first component, referred to as "filtered proportional component", obtained by filtering by a filter in advance phase the flywheel torque error weighted by a first gain called "assistance gain", and secondly a second component, called "derivative return component", obtained by calculating the time derivative of the torque effective flywheel and weighting said time derivative of the effective flywheel torque by a second gain called "derivative gain". Advantageously, the joint use of a proportional component filtered by a phase advance filter and a derivative feedback component makes it possible to base the overall stability of the servocontrol on the phase-advance filter 10, although that it becomes possible to adjust very freely, in an almost independent way, and in particular to increase up to high values, each of the assistance and derivative gains, so as to be able to benefit fully and simultaneously on the one hand of the amplification function of the motor setpoint, and thus of the amplification of the maneuvering force of the direction, provided by the assistance gain, and on the other hand of the improvement (smoothing) function the feeling of the behavior of the direction, provided by the gain of derivative. Indeed, since the stability of the servo is guaranteed by the presence of the phase advance filter, which completes the proportional action of the assistance gain, then the stability of the servo, for a given assistance gain , is almost no longer dependent on the choice of the value of the derivative gain, so that the setting of the derivative gain, and thus the quality of the improvement of the feeling, is de-correlated with the stability adjustment. The invention thus makes it possible to separate the adjustment function of the stability, which is provided by the phase advance filtering, from the feel adjustment function, which is based on the choice of the derivative gain. Consequently, since the setting of the derivative gain no longer interferes with the adjustment of the stability of the servo-control, and in particular with the adjustment of the low-frequency stability (typically below 25 Hz), it is possible, in all circumstances, to adjust and evolve freely over time the derivative gain, 30 in order to optimize the feeling of the behavior of the direction, while remaining free of the choice and the evolution in the time of the gain of assistance, which allows to adapt and optimize at any time the degree of assistance provided by the assistance engine. The respective settings of the stability, by the phase advance filter, of the 35 degree (intensity) of the assistance, by the assistance gain, and the feeling of the behavior of the direction, by the derivative gain, Thus, they are simplified and optimized thanks to the decoupling of these settings obtained by the presence of the phase advance filter. Other objects, features and advantages of the invention will appear in more detail on reading the description which follows, as well as with the aid of the accompanying drawings, provided for purely illustrative and non-limiting purposes, among which: FIG. 1 illustrates, in a schematic view, the implementation of a servo-control method according to the invention within a power steering device. FIGS. 2A and 2B illustrate the Bode diagrams, respectively the gain diagram and the phase diagram, of phase advance filters that can be used by the method according to the invention. The invention relates to a method for controlling a power steering device 1. As illustrated in FIG. 1, the power steering device 1 comprises an assistance motor 2 as well as a steering wheel 3. on which a driver can exert a force, and more particularly a couple, said "flying couple" T3. The power steering device 1 preferably also comprises, in a manner known per se, a rack 4, which is slidably mounted in a steering casing 20 fixed to the chassis of the vehicle. The rack is connected, respectively by a left steering rod 5 and a straight steering rod 6, to a left steering wheel 7 and to a right steering wheel 8, so that the displacement of the rack 4 in translation causes the modification of the steering angle (yaw orientation) of said steerable wheels 7, 8. The steering wheel 3 is preferably fixed on one end of a steering column 10, the other end of which is provided with a pinion gear. 11 which meshes with the rack 4. The assistance motor 2 is preferably an electric motor with two directions of operation, for example a "brushless" motor. The assistance motor 2 is arranged so as to exert an assistance effort, and more particularly a support torque T2, on the rack 4, by means of any suitable transmission mechanism. For this purpose, the assistance motor 2 can for example be engaged on the steering column 10, by means of a gearbox 12, such as a gearbox 3037671 6 with a tangential wheel and worm gear, for to form a so-called "single-pinion" mechanism, as shown in FIG. 1. According to an embodiment variant, not shown, the motor can come into direct engagement with the rack 4, for example by means of a ball screw. or 5 by means of a secondary gear, distinct from the drive gear 11 fixed on the steering column 10, in a so-called "double gear" mechanism. Of course, the method according to the invention is applicable to any type of power steering 1, irrespective of the drive configuration of the rack 4 by the assistance motor 2, and more generally whatever the configuration of the rack. mechanism enabling the assistance motor 2 to modify the orientation of the steered wheels 7, 8. According to the invention, said method comprises a step (a) of defining a flying torque setpoint, during which a steering torque setpoint T3_set which is representative of a flying torque value that one wishes to achieve. The size enslaved by the method is indeed the flying torque T3. According to a first particularly simplified implementation possibility, called "passive conventional servocontrol", the step (a) of defining a flying torque setpoint will be implemented, in a unique and prior manner, during a setting. from the factory, or even during the computer coding of the program corresponding to the servo-control method. The flying torque setpoint T3_set will then be fixed, and arbitrarily chosen to be zero. However, according to a second possibility of implementation, particularly preferred, called "active servocontrol", the step (a) of setting a flying torque setpoint will be repeated periodically, automatically, to allow cooling and the evolution of the flying torque setpoint T3_set over time, depending on the vehicle's life situations. According to this second possibility of implementation, and as shown in FIG. 1, the flying torque setpoint will be generated, in real time, by a flying torque setpoint generator module 13, according to predefined assistance laws. , which can typically be in the form of maps, or maps, which associate with each life situation of the vehicle a flying torque setpoint T3_set which corresponds to the steering wheel torque T3 which should be felt at the moment considered. - of said life situation of the vehicle ..
    [0002] For this purpose, the torque reference generator module 13 uses, on the one hand, "vehicle data" representative of the dynamic situation of the vehicle at the instant in question, such as the longitudinal speed of said vehicle. lateral acceleration of said vehicle, etc., and on the other hand, "direction data", representative of the configuration of the steering device 1 at the moment considered, such as the steering angle, the speed of rotation of the steering wheel, pipe 5 T3, etc., data from which said generator module 13 determines the flying torque setpoint T3_set. The method also comprises a step (b) for measuring the actual flying torque, during which the value, called the "actual flying torque" T3_meas, of the steering wheel torque actually exerted by the driver on the steering wheel 10 is measured. For this purpose, it will be possible to use any suitable torque sensor 14, and for example a magnetic torque sensor, measuring the torsional elastic deformations of a torsion bar interposed between an upstream portion of the steering column 10, which carries the steering wheel 3, and a downstream portion of the steering column 10, which carries the driving pinion 11. The method then also comprises a step (c) of comparison during which the difference, called " "Flying torque error" AT3, between the flywheel setpoint T3_set and the actual flying torque T3_meas: AT3 = T3_set - T3_meas (or conversely, according to the signed sign convention).
    [0003] It will be noted that, by simple representation convention, in FIG. 1, the actual flying pair T3_meas is assigned a positive sign, whereas the flying torque setpoint T3_set is (implicitly) assigned the opposite sign, that is, that is to say, a negative sign (so that we pose here, formally: AT3 = T3_meas - T3_set). Of course, it could be conversely, without departing from the scope of the invention.
    [0004] The method then comprises a step (d) for determining the engine torque setpoint during which an engine torque setpoint T2_set is generated which is intended to be applied to the assistance engine 2 so that the engine of the engine assistance 2 can act to reduce the AT3 flying torque error.
    [0005] In other words, in application of the engine torque setpoint T2_set, the assistance motor 2 will deliver an assist torque T2 which will make it possible to converge the actual steering torque T3_meas to the target value that constitutes the setpoint of Flying torque T3_set, which will reduce the AT3 torque error (ie bring it closer to zero).
    [0006] According to the invention, during the step (d) of determining the motor torque setpoint, the motor torque setpoint T2_set is generated from: a first component, referred to as "component" filtered proportional ratio »CpF, obtained by filtering by a phase-advance filter 15 the flywheel torque error AT3 weighted by a first gain called" assistance gain "Kp, and on the other hand a second component, so-called "Derivative return component" CD, obtained by calculating the time derivative (first) of the effective flying torque: d (T3_meas) / dt, and weighting said time derivative of the actual flying torque by a second gain called "derivative gain" KD.
    [0007] The assistance gain Kp, which here corresponds to a (proportional) amplification coefficient of the torque error AT3, may advantageously be provided by an appropriate mapping, and may if necessary evolve in real time, so as to to adapt to each situation of life of the vehicle the dosage of the assistance, and in particular the degree of amplification of the torque error AT3 and thus the final intensity of the assist torque T2 delivered by the assistance engine 2 The setting (the choice) of the assistance gain Kp will therefore make it possible to define the desired level of assistance, ie to quantify the degree of intervention of the assistance motor 2 (with respect to the manual effort T3 exerted by the driver) in the global action (manual and motorized) of maneuver of the direction 1.
    [0008] Similarly, the derivative gain KD will, by a proportional action on the value of the time derivative of the actual flying torque d (T3_meas) / dt, define the feeling of the behavior of the steering, and more particularly to choose the degree smoothing the feeling of management behavior.
    [0009] Said derivative gain KD may also be defined by appropriate mapping, and be able to evolve over time, depending on the life situation of the vehicle. Although it is not excluded to use, according to the configuration and the programming convention adopted to implement the method, a unit gain gain Kp or a unity derivative gain KD, said gains Kp, KD will be preferably non-unitary, and advantageously adjustable according to the needs, and in particular according to the life situation of the vehicle. Furthermore, it will be noted that the servocontrol proposed by the invention, and in particular the joint use of a derivative feedback component CD and a phase advance filter applied to the AT3 flying torque error. , as described above, is equally applicable to passive conventional servocontrol, in which the flywheel setpoint T3_set is fixed and zero (and therefore the steering torque error AT3 simply equal to the value measured effective flywheel torque T3_meas), only active servo, in which is determined in real time a flying torque set T3_set evolutionary (and most often non-zero).
    [0010] In the case of passive conventional servocontrol, in the absence of a setpoint (non-zero) of flywheel torque T3_set, the invention will simply be to use together on the one hand a derivative return component CD as described herein below. above, calculated from the derivative of the effective flywheel torque T3_meas, and secondly a phase advance filter 15 applied to a simply and directly proportional value (via the assistance gain Kp) to the measured value of the torque effective flywheel T3_meas. In other words, the passive conventional servo-control, particularly simplified, will calculate the filtered proportional component CpF only from the return that constitutes the measurement of the actual flying torque T3_meas. In any case, and in particular that one is in the presence of a fixed and zero flying torque setpoint T3_set, or on the contrary in the presence of a variable and (potentially) non-zero variable torque setpoint, the use of a phase advance filter 15 associated with the flywheel torque error AT3 and a branching module 16 providing a derivative return of the effective flywheel torque T3_meas makes it possible, as indicated above, to on the one hand, to cumulate the beneficial effects of a freely chosen amplification of assistance (by the filtered proportional component CpF), and in particular of a significant amplification of the assistance, on the other hand a level of feeling of the behavior 25 direction 1 which will be freely chosen (by the derived component CD), and in particular that will be effectively smoothed to limit or even "erase", saccades and other impressions of gravity or delays, while ensuring the stab itity, and in particular the low frequency stability of the servocontrol (thanks to the phase advance filter 15).
    [0011] As such, it will be noted that the mechanical part of the steering device 1, which comprises in particular the various components that are the steering wheel 3, the steering column 10, the torsion bar of the torque sensor 14 inserted on said column 10, the drive pinion 11, the rack 4, the steering rods 5, 6 and the guide wheels 7, 8 can be broadly likened to a mass-spring system or mass-spring-damper.
    [0012] In particular, the spring effect may be derived from the intrinsic elasticity of the mechanical members, and in particular easily deformable mechanical members such as the torsion bar of the torque sensor 14 or the tires which equip the wheels 7, 8.
    [0013] However, such a mass-spring system (or mass-spring-damper) has (at least) a fundamental frequency (resonance frequency) fo, in practice typically between 12 Hz and 20 Hz. In this low frequency domain ( here less than 25 Hz, or even 22 Hz, and more particularly less than or equal to 20 Hz), it is therefore necessary to define the (overall) gain of the servocontrol so that there is no risk of falling into an unstable (oscillating) mode when the steering mechanism 1 is excited. For this purpose, it is therefore necessary to preserve, regardless of the assistance gain Kp, a gain margin (value of gain it It would be necessary to add to bring the system to the limit of sufficient stability, that is to say graphically a sufficient distance between the place of Nyquist (representation, in the complex plane, of the transfer function of the servocontrol in open loop) and the coordinate point (-1, 0). This is the role filled by the phase advance filter 15. The phase advance filter 15 can be of any suitable type, provided that said filter 15 can give the signal it processes (here the torque error steering wheel weighted by the assistance gain) a phase advance, that is to say, apply a positive phase shift Acp. Preferably, the phase advance filter is a first order filter.
    [0014] Such a choice makes it possible to carry out a simple, fast filtering that is not very greedy in computing resources, and which nevertheless makes it possible to efficiently ensure a sufficient stability, by compensating in particular the destabilizing effects of an increase in the assistance gain Kp. Of course, the phase advance filter 15 may be chosen of any order n equal to or greater than 1, and for example form a filter of the second or third order. Whatever the order n retained, the phase shift (maximum) Acp thus obtained by a phase advance filter of order n, that is to say in this case the phase advance Acp (maximum) and introduced, will be + n * 90 degrees, as shown in particular in Figure 2B.
    [0015] Likewise, the gain maximum G (dB) of amplification of said phase advance filter 15 will be + n * 20 dB. Preferably, the phase advance filter 15 is in the form: H (s) - 1+ Ti.s 1 + T2 .s 5 with: = 11 (2.7-c.fi), where f1 represents a first frequency cutoff, T2 = 11 (2.7-c.f2), where f2 represents a second cutoff frequency (higher than the first cutoff frequency f1), s is the Laplace operator.
    [0016] Such a filter 15 corresponds to the diagrams illustrated in FIGS. 2A and 2B. It advantageously offers, between the cutoff frequencies f1, f2, a phase advance plateau Acp = + n * 90 degrees, as well as a gain ramp (which starts at the first cut-off frequency f1 and which then peaks at 15 ° C. asymptotically from, and beyond, the second cutoff frequency f2). Such a filter 15 advantageously makes it possible to define, in a simple and inexpensive way in computing resources, the interval [f1; f2] wherein said filter actively advances the phase, and therefore actively acts to stabilize the servo. In practice, the cut-off frequencies f1, f2 will preferably be chosen so as to frame the fundamental frequency fo of the steering mechanism. As an indication, the first cutoff frequency fi. (minimum) may be substantially equal to 6 Hz, while the second cutoff frequency f2 (maximum) may be substantially equal to 22 Hz. Preferably, the phase advance filter 15 having at least a first cutoff frequency f1 , and preferably a first and a second cut-off frequency f1, f2, the cut-off frequency, and preferably the cut-off frequencies f1, f2, is adjusted as a function of the longitudinal speed Vvehic of the vehicle which is equipped with the steering device assisted 1, as shown in Figure 1.
    [0017] It can thus be advantageously taken into account that the stability margin (typically the gain margin) can be different at standstill (zero Vvehic speed) and while driving (non-zero Vvehic speed). Indeed, for example, the elasticity of the tire can intervene more significantly in rolling than at rest, and thus change the fundamental frequency fo of the steering mechanism.
    [0018] Similarly, the need for assistance in the maneuver of the direction 1 is more important in the case of parking (speed substantially zero), or low speed traffic (typically between 0 and 50 km / h). ) that it is at a higher speed. There will therefore be a tendency to increase the low speed Kp assist gain, especially as the Vvehic speed approaches zero, which will have an adverse effect on the stability, and as such will require more compensation. 15). More particularly, the first cut-off frequency f1 being strictly less than the second cut-off frequency f2, it is possible to increase the first cut-off frequency f1 and / or to decrease the second cut-off frequency f2. when the longitudinal velocity of the vehicle Vvehic increases, so as to reduce the interval [f1; f2] between the first cutoff frequency f1 and the second cutoff frequency f2. Thus, it will be possible to reduce the frequency interval [f1; f2] corresponding (substantially) to the width of the phase advance plate Acp when the speed of the vehicle Vvehic increases, especially when the vehicle goes from a stopping situation (zero speed) to a rolling situation (speed not zero), and / or when the vehicle speed Vvehic increases in a low speed range, typically between 0 km / h and 50 km / h.
    [0019] On the other hand, the interval [f1; f2] when the speed of the vehicle decreases, especially when said speed falls below 50 km / h, and in particular when said speed is canceled. Preferably, when changing the width of the interval [f1; f2], it remains substantially centered on the same central frequency, constant, equal to 25 1/2 (f1 + f2), said central frequency possibly corresponding to the fundamental frequency fo of the steering mechanism when the vehicle is at shutdown. Furthermore, preferably, when calculating the derivative feedback component CD, a low-pass filter 17 is applied in order to reduce the digital noise (of high frequency).
    [0020] Said low-pass filter 17 will preferably be applied after weighting by the derivative coefficient Kip, which weighting itself follows the bypass module 16, as illustrated in FIG. 1. The low-pass filter 17 Preferably, it will have a cut-off frequency fc of between 150 Hz and 200 Hz, in particular if the sampling frequency at which the servo cooling takes place, and in particular the refreshing of the measurement of the actual flying torque T3_meas and the calculation of the derivative of said effective flying torque is substantially equal to 1 kHz, which corresponds to a sampling period of one millisecond. Thanks to said low-pass filter 17, digital noise with a frequency higher than said cut-off frequency fc can be eliminated.
    [0021] It will be noted that during step (d) of determining the motor torque setpoint, the algebraic sum of the filtered proportional component CpF and the derivative feedback component CD is preferably produced. Although other forms of combination of these components CpF, CD are conceivable, the algebraic sum has the advantage of a great simplicity. The filtered proportional component CpF and the derivative return component CD, as well as their algebraic sum, are homogeneous with a torque setpoint T2_set. If necessary, said algebraic sum of the filtered proportional components CpF and derivative feedback CD can be used as such as torque setpoint T2_set. However, according to one possible variant of implementation, it is also possible to add, to said algebraic sum, filtered proportional components CpF and derivative derivative CD, other corrective components, such as an anticipation component. and / or a compensation component, to form, in fine, the engine torque setpoint T2_set which is then applied to the assistance engine 2. An "anticipation component", also called "pre-positioning component", is a corrective component, of the offset type, which is introduced immediately into the motor torque setpoint T2_set, typically to increase the magnitude of said engine torque setpoint T2_set, when it is known in advance, even before applying to the assistance motor 2 the motor torque setpoint T2_set, that the steering system will behave exactly as one would like it to behave.
    [0022] By way of example, if one observes systematically the appearance of a non-zero static error whose value is known, the anticipation component will make it possible to increase the algebraic sum of the filtered proportional component CpF and the CD derivative return component of an (offset) value corresponding to said static error.
    [0023] For example, a "compensation component" may be intended to compensate for the effects of dry friction or the effects of the inertia of the steering mechanism. In the case of dry friction, an estimated value of said friction may be calculated by any appropriate means, and then a friction compensation component whose value will correspond to said estimated value of the friction. In the case of inertia, which tends to induce a delay in the reaction of the system, it will be possible for example to calculate an inertia compensation component whose value will be equal to the product of a gain (called "derivative gain"). second "), representative of the inertia, by the second time derivative of the angular position of the steering wheel (that is to say the angular acceleration of the steering wheel). Of course, the invention also relates as such to a servo control module 20 for a power steering device 1 comprising a torque steering setpoint generator module T3_set, a modulus (sensor) 14 for measuring the actual flywheel torque T3_meas , an amplification module 21 making it possible to generate the filtered proportional component CpF from the flying torque error AT3, and a derivative return module 22 making it possible to generate the derivative return component CD from the actual flying torque T3_meas measured.
    [0024] The amplification module 21 advantageously forms a first branch, called a "proportional branch", which comprises a first weighting module 23 in which the flywheel torque error AT3 is multiplied by an assistance gain Kp, so that obtain a gross proportional component, as well as a phase advance filter applied to said raw proportional component so as to obtain a filtered proportional component CpF. The derivative return module 22 forms a second branch, called a "derivative return branch", distinct from the first proportional branch, and which successively comprises a bypass module 16 which calculates the first time derivative of the actual flying torque. d (T3_meas) / dt, a second weighting module 24, which multiplies the first time derivative of the actual steering wheel torque by the derivative gain KD, and a low-pass filter 17 which eliminates the digital noise. The two branches 21, 22 then meet (by their respective downstream portions, that is to say in particular downstream of the phase-advance filter 15 for the first proportional branch 21, and downstream of the branching module 16, and more particularly downstream of the low-pass filter 17, for the second derived return branch 22) in an algebraic sum, which combines the filtered proportional components CpF and derivative feedback CD, and serves as a basis for the instruction motor torque T2_set. Any module 16, 20, 21, 22, 23, 24 and any filter 15, 17 mentioned above, and in particular the control module 20 as a whole, the phase advance filter 15, the bypass module 16 and more generally the derivative return module 22, can be realized by any appropriate computer, computer, electronic card or programmable logic controller, the structure of the modules and filters can be physical, and defined by the wiring of the electronic components, 10 and / or virtual, and obtained by computer programming. The invention is of course in no way limited to the aforementioned embodiments, the person skilled in the art being able in particular to isolate or combine freely between them one and / or the other of the characteristics described in the foregoing. or substitute equivalents for them.
    [0025] In particular, it is not excluded to modify the order of application of the assistance gain Kp and the phase advance filter 15 within the proportional branch 21, or the order of application of the derivation 16, the derivative gain KD and the low-pass filter 17 within the derivative return branch 22. 20
    权利要求:
    Claims (7)
    [0001]
    REVENDICATIONS1. A method of servoing a power steering device (1) comprising an assistance motor (2) and a driving wheel (3) on which a driver can exercise a force, said "flying torque" (T3) , said method 5 comprising a step (a) of defining a flying torque setpoint, during which a flying torque setpoint (T3_set) representative of a flying torque value which one wishes to achieve is generated, a step (b) for measuring the actual flying torque, during which the value, called the "actual flying torque" (T3_meas), of the steering wheel torque actually exerted by the driver on the steering wheel (3) is measured, a comparison step (c) during which the difference, called the "flying torque error" (AT3), is determined between the flying torque set point (T3_set) and the actual flying torque (T3_meas), a step (d) engine torque setpoint determination during which one generates a a motor torque setpoint (T2_set) which is intended to be applied to the assistance motor (2) so that the assistance motor can act to reduce the flywheel torque error (AT3), said method being characterized in that, in the step (d) of determining the engine torque setpoint, the engine torque setpoint (T2_set) is generated from a part of a first component, referred to as "filtered proportional component" (CpF), obtained by filtering by a phase-advance filter (15) 20 the flywheel torque error (AT3) weighted by a first gain called "assistance gain" (Kp), and on the other hand a second component, called "derivative return component" (CD), obtained by calculating the time derivative of the actual flying torque (d (T3_meas) / dt) and weighting said time derivative of the actual flying torque by a second gain said "Derivative gain" (KD). 25
    [0002]
    The method of claim 1 wherein the phase advance filter (15) is a first order filter.
    [0003]
    3. Method according to claim 1 or 2 characterized in that the 1 + T phase advance filter is in the form: H (s) = s with: T = 1 / (2.iz.f), where f1 represents a first cutoff frequency T2 = 11 (2.7-c.f2), where f2 represents a second cutoff frequency s is the Laplace operator.
    [0004]
    4. Method according to one of the preceding claims, characterized in that the phase-advance filter (15) having at least a first cut-off frequency (f1), and preferably a first and a second cut-off frequency (f1). , 1 + T2 .s 3037671 17 f2), the cutoff frequency, and preferably the cut-off frequencies, is adjusted as a function of the longitudinal speed (Vvehic) of the vehicle equipped with the power steering device (1).
    [0005]
    5. Method according to claims 3 and 4 characterized in that, the first cutoff frequency (f1) being strictly less than the second cutoff frequency (f2), the first cutoff frequency (f1) and / or the the second cut-off frequency (f2) is decreased when the longitudinal speed (Vvehic) of the vehicle increases, so as to reduce the interval ([f1; f2]) between the first cutoff frequency and the second cutoff frequency.
    [0006]
    6. Method according to one of the preceding claims, characterized in that, in calculating the derivative feedback component (CD), a low-pass filter (17) is applied in order to reduce the digital noise.
    [0007]
    7. Method according to one of the preceding claims characterized in that, during step (d) of determining the motor torque setpoint (T2_set), the algebraic sum of the filtered proportional component (CpF) and the derivative return component (CD).
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    公开号 | 公开日
    US20180134309A1|2018-05-17|
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    EP3310640A1|2018-04-25|
    BR112017025889A2|2018-08-14|
    EP3310640B1|2020-08-26|
    CN107771146B|2020-07-31|
    FR3037671B1|2017-06-16|
    US10889319B2|2021-01-12|
    JP2018517604A|2018-07-05|
    CN107771146A|2018-03-06|
    JP6768003B2|2020-10-14|
    引用文献:
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    EP1714852A2|2005-04-18|2006-10-25|Jtekt Corporation|Electric power steering apparatus|
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    US20130311044A1|2011-03-29|2013-11-21|Jtekt Corporation|Electric power steering apparatus|
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    EP3378731B1|2017-03-20|2020-01-15|Volvo Car Corporation|Apparatus and method for driver activity dependentwheel angle controller|
    FR3071473B1|2017-09-25|2021-12-10|Jtekt Europe Sas|ADAPTATION OF A DERIVATIVE GAIN AS A FUNCTION OF THE FLYING TORQUE TO IMPROVE THE FEELING OF A POWER STEERING SYSTEM|
    FR3075154B1|2017-12-15|2019-11-22|Jtekt Europe|METHOD FOR MONITORING THE OPERATION OF AN ASSISTED STEERING SYSTEM|
    FR3075155B1|2017-12-20|2020-10-23|Jtekt Europe Sas|IMPROVEMENT OF THE FEELING OF A ROAD PROFILE BY VARIATION OF A GAIN ACCORDING TO VEHICLE SPEED AND FLYING TORQUE|
    CN109533013B|2018-11-30|2021-02-19|北京经纬恒润科技股份有限公司|Electric power steering system and friction compensation method and controller thereof|
    法律状态:
    2016-04-21| PLFP| Fee payment|Year of fee payment: 2 |
    2016-12-23| PLSC| Search report ready|Effective date: 20161223 |
    2017-04-21| PLFP| Fee payment|Year of fee payment: 3 |
    2018-04-27| PLFP| Fee payment|Year of fee payment: 4 |
    2020-04-29| PLFP| Fee payment|Year of fee payment: 6 |
    2021-03-25| PLFP| Fee payment|Year of fee payment: 7 |
    优先权:
    申请号 | 申请日 | 专利标题
    FR1555640A|FR3037671B1|2015-06-19|2015-06-19|USING A PHASE ADVANCE FILTER TO SEPARATE THE SPRING ADJUSTMENT FROM THE STEERING WHEEL ADJUSTING THE STABILITY OF AN ASSISTED STEERING CONTROL|FR1555640A| FR3037671B1|2015-06-19|2015-06-19|USING A PHASE ADVANCE FILTER TO SEPARATE THE SPRING ADJUSTMENT FROM THE STEERING WHEEL ADJUSTING THE STABILITY OF AN ASSISTED STEERING CONTROL|
    JP2017560536A| JP6768003B2|2015-06-19|2016-06-17|Use of phase lead filter to separate manual steering setting from power steering control stability setting|
    BR112017025889A| BR112017025889A2|2015-06-19|2016-06-17|using a phase advance filter to separate manual steering wheel adjustment from power steering stability control|
    CN201680035895.XA| CN107771146B|2015-06-19|2016-06-17|Using a phase lead filter to separate manual steering settings from power steering control stability settings|
    PCT/FR2016/051478| WO2016203171A1|2015-06-19|2016-06-17|Use of a phase-lead filter to separate the manual steering setting from the power steering control stability setting|
    EP16741086.9A| EP3310640B1|2015-06-19|2016-06-17|Use of a phase-lead filter to separate the setting of steering feel from the setting of control stability for a power steering|
    US15/574,537| US10889319B2|2015-06-19|2016-06-17|Use of a phase-lead filter to separate the manual steering setting from the power steering control stability setting|
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