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    • 专利摘要:
    - A method for determining the absolute angular position of a crankshaft target of a heat engine, the target having a plurality of teeth, wherein is acquired by means of a sensor at least one signal representing the passage of each tooth in front of said sensor in function of time. The following steps are then performed: i. during an operating phase of the motor, the absolute angular position is generated from the signal and the period of a tooth; ii. during a stopping phase of the motor, when the determination of the period is no longer possible, the number of the tooth passing in front of the sensor is continuously determined; and iii. during a motor restart phase, the so-called tooth number is used to decrease the duration of cycle synchronization time.
    公开号:FR3018856A1
    申请号:FR1452384
    申请日:2014-03-21
    公开日:2015-09-25
    发明作者:Thierry Lepage；Farid Tahiri
    申请人:IFP Energies Nouvelles IFPEN；Scaleo Chip SA；
    IPC主号:
    专利说明:

    [0001] The present invention relates to the field of motor control and synchronous data acquisition with the revolution of the engine crankshaft. More particularly, the invention relates to the field of angular prediction methods for determining the precise geometrical position of the crankshaft.
    [0002] The invention can find applications in engine design laboratories to assist in the design of automotive engine control systems. It can also be integrated into engine control systems within a production vehicle. During the operating cycle of an internal combustion engine, many actions must be synchronized to the geometrical position of the crankshaft. This is the case of the control of the fuel injection, the control of the spark plugs, and the management of the distribution members. The control of actuators such as fuel injectors or ignition coils must be at particular angular positions of the engine cycle.
    [0003] The industrialization, more and more frequently on a production vehicle, of processing algorithms for optimizing engine performance requires the acquisition of signals on precise angular windows, as well as measuring the instantaneous speed of the engine. . For example, it is necessary to know the angular position of the crankshaft and its instantaneous speed, in the context of control systems for optimizing the operating point of an internal combustion engine by the processing, in real time, of parameters. significant of its operation, such as the pressure in the various combustion chambers at a series of successive instants of each combustion cycle. To perform these various actions, a motor is equipped with a computer which must have precise information on the position of the crankshaft. To meet these needs, the crankshaft is equipped with a toothed wheel and a sensor that detects the passage of teeth in order to inform the computer in charge of controlling the control organs and / or control. This gear is called a "motor target".
    [0004] The latter is a disc usually placed at the flywheel. Teeth are machined on the periphery of this disc in a regular manner. To ensure round synchronization, it is common to create a singularity by deleting one or more teeth. These teeth are called "missing teeth". A target very often encountered in Europe has 58 teeth on its periphery. It is in fact a regular machining of 60 teeth, each having a width of 6 ° V and a singularity defined by the absence of 2 teeth. This topology is commonly called 58X or 60-2. To generalize, we can consider that a crankshaft target can have several singularities on its periphery. The interval between each singularity being named sector. Each sector consists of a series of regular teeth followed by a singularity of n teeth. We can express the target in the form: p * (m - n) with - p: Number of sectors per engine revolution where the geometry (mn) is defined - m: Number of regular teeth that would comprise the sector without singularity - n: Number of missing teeth on the sector (size of singularity) To use the example of target 58X, it is defined as "1 * (60 - 2)". However, in order to use a motor target, it is necessary to be able to position a tooth numbered 1 with a perfectly known position, that is to say that one must be able, from the sensor signal, to determine the precise moment when a particular tooth (tooth 1) passes in front of the sensor. The detection of the singularity characterized, as described above, by the absence of one or more teeth, makes it possible to have an absolute reference, thus indicating the precise position of the crankshaft. By definition, tooth 1 can be attached as the one following the two missing teeth. The motor targets are associated with a sensor which is intended to detect the passage of the teeth. This signal delivered by this sensor is analog in the case of a variable reluctance sensor and must be conditioned to be operated. The result of this conditioning is a signal (CS) in which a rising or falling edge is the reflection of the middle of a tooth. In the case of a hall sensor, the delivered digital signal can be directly exploited. It is precisely on the detection of this rising or falling edge that the computers are based to synchronize the operation of the engine. In addition to information from an instrumented sensor on the camshaft (AAC), the exact knowledge of the geometrical position of the crankshaft makes it possible to precisely position the injection and / or injection windows on a motor cycle. ignition for each of the cylinders. However, the control of the actuators of the thermal engines requires an angular resolution of the order of 0.1 °, thus much higher than that obtained by the raw signal (CS) delivered by the crankshaft sensor (6 ° for a target of type 1 * ( 60-2)). To obtain high resolution information on the angular position of the crankshaft target, it is known to interpolate the raw signal (CS) to increase the angular resolution. The method used consists in using a digital PLL ("phase-locked loop", also called a phase-locked loop) whose operating period is programmed equal to the period of the tooth fraction to be generated. The latter is obtained by dividing the period of a tooth that is to be interpolated, by the number of tooth fractions that it is desired to generate. One is led to make a fractional division and to manage by successive accumulations the fractional parts in order not to lose in precision. Also known, for example that described in French Patent Application No. 13/61854, a method for determining the instantaneous angular position of a crankshaft target overcoming these problems. During this process, the angular resolution of the signal is increased by means of interpolation and a high resolution signal is generated representing the passage of tooth fractions past the sensor as a function of time. Figure 1 shows the different synchronization phases of such a system.
    [0005] A) tooth synchronization phase: During this phase, we typically measure three consecutive periods (teeth) to be certain not to be on a singularity. B) Sector synchronization phase: During this phase, we try to detect the singularity C) Phase synchronization cycle: During this phase, we try to detect a known profile on the target camshaft. D) Synchronized system As this figure illustrates, the total duration of the synchronization phase is dependent on the number of sectors of the crankshaft target, the number of profiles that can be identified on the target camshaft and the condition engine stop: number of teeth between the stop position and the first singularity of the crankshaft target. For a 58X target and a single crankshaft target, this can be up to two engine revolutions. The measurement of the period of the crankshaft teeth is the main source of information of such a system. During the engine stop phase, when the engine speed decreases, the tooth period increases to exceed the measurement capabilities of the system causing a desynchronization of the system and forcing a complete synchronization at each engine start.
    [0006] The object of the invention relates to a method for determining the absolute angular position of a crankshaft target of a heat engine, making it possible to overcome this problem. The method includes a step for optimizing the synchronization phase. To do this, the number of the tooth passing in front of the sensor is continuously determined during a stopping phase of the motor. This information is then directly used at startup to synchronize the system. This step significantly reduces the duration of the synchronization phase. This can be an important factor for "Stop & Start" type applications for which a quick restart of the motor is desired, since they involve frequent stopping and restarting phases of the engine. The invention relates to a method for determining the absolute angular position of a crankshaft target of a heat engine, the target having a plurality of teeth, in which at least one signal is acquired by means of a sensor. representing the passage of each tooth in front of said sensor as a function of time, characterized in that i. during a running phase of the motor: a period of a tooth is determined; increasing the angular resolution of said signal by generating over the period a high resolution signal representing the passage of fractions of the tooth in front of said sensor as a function of time; the absolute angular position is generated from said signal and said period; ii. during a stopping phase of the motor, when the determination of the period is no longer possible, the number of the tooth passing in front of the sensor is continuously determined; and iii. during a restart phase of the motor, said tooth number is used to reduce the cycle synchronization time. In step i, the absolute angular position can be generated by performing the following steps: a. determining the position of at least one missing tooth on the target from said high resolution signal; b. determining the position of at least one sector from the position of said missing tooth; c. the sector of which the position is determined is identified among the sectors of the target, as well as the revolution number of the cycle by means of a counter synchronization mechanism. In step i, the period of the tooth, from a period of the previous tooth or from an internal measurement, or information from an external device can be determined. The number of the identified tooth can be initialized by determining the position of at least one missing tooth on the target from said high resolution signal during a first engine start phase. In step iii, the absolute angular position can be generated by performing the following steps: a- a tooth synchronization is performed (3- the sector and revolution number of the cycle is identified from the number of the tooth identified with step ii.
    [0007] Before step a: it is possible to determine the position of at least one missing tooth on the target from said high resolution signal, and a second tooth number is deduced therefrom compared to the number of the tooth identified. in step ii; if said tooth numbers are not identical, the second tooth number can be used, then the value of the current tooth number is initialized. In addition, a signal indicating the direction of rotation of the sensor can be used to determine the number of the tooth passing in front of the sensor during the stopping phase of the motor.
    [0008] The angular resolution of said signal can be increased by interpolating the signal on each tooth period using the Bresenham algorithm. The acquired signal may be the signal measured in real time by a crankshaft sensor with a hall effect. Other features and advantages of the method according to the invention will appear on reading the following description of nonlimiting examples of embodiments, with reference to the appended figures and described below. Brief presentation of the figures Figure 1 shows the different synchronization steps of a method according to the prior art. Figure 2 shows a block diagram of the method according to the invention. Figure 3A illustrates the crankshaft signal obtained from the output of a crankshaft sensor for a target 58X (the x-axis representing time, and the y-axis representing the amplitude of the sensor signal).
    [0009] FIG. 3B is a zoom of the dotted rectangle of FIG. 3A, and further illustrates a high resolution signal (TOP FTTH), as well as the instantaneous angular position (POS CYCLE FTTH) in the form of an angle between 0 and 719. °. A resolution of the high resolution signal was set at 1 ° to make the figure readable.
    [0010] Figure 4 depicts the method for determining the instantaneous angular position of a crankshaft target of a heat engine. Figure 5 shows the principle of detection of a missing tooth. Figure 6 shows the principle of detecting two missing teeth. Figure 7 describes in detail the target reconstruction module.
    [0011] Figure 8 shows, on a particular case of AAC signal, the synchronization principle to obtain the sector number and the revolution number. FIG. 9 shows the gain obtained over the synchronization time with respect to FIG. 1: The overall system is completely synchronized as soon as the tooth synchronization is completed, typically obtained after three crankshaft teeth (phases B and C are no longer required). Figure 10 shows how, from the 'Cur Tooth num' value which continues to evolve during the engine stop phase, the system is able to fully synchronize as soon as it has synchronized tooth .
    [0012] The same references are used on each figure and throughout the description. DETAILED DESCRIPTION OF THE PROCESS Referring now to FIG. 2 which describes the method according to the invention for determining the absolute angular position of a crankshaft target of a heat engine, the target comprising several teeth. One calls instantaneous angular position, the angle between a fixed reference on the crankshaft target (tooth n ° 1 for example) and a fixed reference mark outside the target (crankshaft sensor), at a time t. This method comprises the following steps: 1. at least one raw signal is acquired by means of a sensor, representing the passage of each tooth in front of the sensor as a function of time; 2. the absolute angular position of the target is determined during a running phase of the engine; 3. the number of the tooth passing in front of the sensor is continuously determined during a stopping phase of the motor; and 4. the absolute angular position of the target is determined during a restart phase of the engine. 1. Acquisition of a raw signal from a tooth-passing sensor During this step, at least one signal (OS) representing the passage of each tooth in front of the sensor is acquired in real time by means of a sensor. function 5 of the time. To do this, it is common to exploit the information from a sensor placed on the flywheel called crankshaft sensor. Crankshaft signal is the signal obtained from the output of a crankshaft sensor and caused by the passage of the teeth of the crankshaft target in front of this sensor. The crankshaft sensor is generally of the variable reluctance or hall effect type. It is placed near a crankshaft target whose evolution it will follow. The signal (OS) issuing from such a sensor is represented in FIGS. 3A and 3B, in the case of a target 58X. A rising or falling edge of the crankshaft signal is the reflection of a tooth. It is precisely on the detection of this rising or falling edge that the computers are based to synchronize the operation of the motor. The first rising edge that follows the singularity therefore indicates the middle of the first tooth (tooth numbered 1) for a variable reluctance sensor or the beginning of the first tooth (tooth numbered 1) for a hall effect sensor of the crankshaft target. The second forehead naturally corresponds to the second tooth and so on until the 581st tooth. 2. Determination of the absolute angular position of the target, during a phase of engine operation. This step is performed when the engine is running, that is to say outside the stopping phases and the restarting phases. This step comprises the following steps: a period of a tooth is determined; increasing the angular resolution of said signal by generating over the period a high resolution signal representing the passage of fractions of the tooth 30 in front of said sensor as a function of time; the absolute angular position is generated from said signal and said period; With reference to FIG. 2, this step can be performed by at least three modules: a module "Teeth Module" responsible for filtering the crankshaft signal, measuring the period of the teeth, creating a high-resolution signal representing each fraction of tooth and ensure the detection of missing teeth and indirectly the detection of singularity. a module "Target Module" responsible for reconstructing the absolute angular position of the crankshaft target according to the mechanical parameters thereof. It relies for this information from the module "Teeth Module" and a cycle synchronization information from the module "Cam Module". This last information can also come from a dedicated algorithm when the engine is not equipped with a camshaft. a module "Cam Module" responsible for identifying particular profiles of the camshaft signal on angular windows of the sector of the crankshaft target for transmitting synchronization information to the module "Target Module".
    [0013] An example of a method for performing this step 2 of the method according to the invention is described below with reference to FIG. 4. Increasing the angular resolution of the raw signal (SHR) During this step, the angular resolution is increased of the raw signal (CS). To do this, we interpolate the raw signal (CS) on each tooth period using the Bresenham algorithm. The period of tooth (or tooth duration) is the period of time between the detection of two consecutive teeth. In this way, a high resolution signal (TOP FTTH) 20 representing the passage of tooth fractions in front of the sensor as a function of time is generated by interpolation. A tooth fraction is represented by the period of a pulse of the high resolution signal obtained from the crankshaft signal. From information on the period of the tooth to be considered, we try to generate events corresponding to fractions of teeth (ftth). The number of tooth fractions to be generated per tooth period is a parameter defining the desired resolution for the high resolution signal. The number of fractions thus makes it possible to adjust the resolution according to the profile of the crankshaft target. For example, for a target 1 * (60-2), one can choose to generate 60 tooth fractions per tooth to have a resolution of 0.1 °. The origin of the period information may be directly derived from the measurement of the period of the previous tooth or may be the result of a calculation seeking to correct defects in tooth machining or motor acyclism. To generate a high resolution signal, representative of tooth fractions (ftth), pulses are generated from the raw signal for each tooth fraction (see FIG. 3B). To do this, one relies on the Bresenham algorithm which was originally used to draw line segments on a computer screen or an image calculated for printing.
    [0014] After some optimizations to remove the fractional numbers difficult to treat simply, one arrives at: Initial conditions: y = 0; error = -X for each increment along the x-axis error = error + 2 * Y if error> 0 then y = y + 1 error = error - 2X end if end for When setting X, the period of the tooth on which to generate the tooth fractions, and Y the number of tooth fractions to be generated, and by applying this algorithm, Y representative pulses of tooth fractions are generated during the period X.
    [0015] An advantage of this algorithm is to be able to carry out a high-resolution signal generation process by consuming few resources in a program logic, an asic or a SoC. The period X of the tooth n can be determined from the period of the previous tooth n-1, or from an internal measurement, or from information from an external device. Determination (DetPOS) of the instantaneous angular position of the target. This step is performed by the module named "Target Module". During this step, the instantaneous angular position (POS CYCLE FTTH) of the target is determined by means of said high resolution signal (TOP FTTH). Firstly, to determine the angular position of the crankshaft target, at least one missing tooth (POSDM) is detected. To do this, one counts the number of pulses generated since the last detection of teeth, and one fixes a threshold of number of pulses. Thus, when the number of pulses generated since the last tooth detection is greater than a given threshold, then a missing tooth is detected. Thanks to the high resolution signal (TOP FTTH) thus generated, it is possible to follow the width of the current tooth. Indeed, from the period of the tooth (X) pulses 35 are generated in a regular manner. At each beginning of the tooth, a first decounter (dcnt iftth) is loaded with the number of tooth fractions to be generated. During tooth n + 1, pulses are generated by using the period measured on tooth n. If the speed of the motor is constant and perfectly regular, the down-counter reaches 0 when the new tooth is detected. In case of deceleration or acceleration, the period of the tooth n + 1 is different from that of the tooth n (higher in case of deceleration, lower in case of acceleration). In these cases, the down-counter does not reach O. For an acceleration, the up-down value is positive. For a deceleration, it is negative (the down-counter is signed, it can process the negative numbers). Figure 5 shows the principle of detection of a missing tooth. The top line shows the position of the teeth (TTH). The next line shows the value of the decounter (dcnt iftth), from 0 to 60 fractions of teeth, as a function of time. The bottom line indicates the presence (1) or not (0) of a missing tooth (MISSING TTH). In principle, the decounter (dcnt iftth) continues to decrement until a new tooth has been detected. On the front of tooth # 3, the module starts the generation of tooth fractions taking as reference the last period measured: the period t2. At the end of this time and failing to detect tooth # 4, the countdown continues to decrement. The value provided by this down counter is followed, and when this value reaches a threshold (missing tth thr) that can be set to the equivalent of a half-tooth in negative, we consider that we are in the presence a missing tooth. The decounter (dcnt iftth) is reloaded with the number of tooth fractions to be generated on a tooth, which makes the value of the tooth positive. When tooth # 5 is detected, the system resumes a normal cycle. The period t taken into account as a time base is the average of t3 'and t4'. Figure 6 presents the principle of detection of two missing teeth. The top line shows the position of the teeth (TTH). The next line shows the value of the decounter (dcnt iftth), from 0 to 60 fractions of teeth, as a function of time. The bottom line indicates the presence (1) or not (0) of a missing tooth (MISSING TTH). The detection mechanism of the missing first tooth is similar to what has been presented previously. On the other hand, if tooth 5 is not detected, and as for the first missing tooth, the down-counter (dcnt iftth) continues to decrement until it reaches the threshold equivalent to a negative half-tooth again. It is considered that there is a new missing tooth and the counting device (dcnt iftth) is reloaded again. When tooth # 6 is detected, the module resumes a normal cycle. The period t taken into account as a time base is the average of the pseudo periods t3 ', t4' and t5 '. This mechanism can thus detect other missing consecutive teeth.
    [0016] Thus, the method is capable of detecting a series of missing teeth. By comparing an internal counter of missing teeth with a defined parameter, it is easy to point out the detection of the singularity. This mechanism can also detect any missing tooth or group of missing teeth. The origin of missing teeth may be voluntary: removal of one or more teeth on the target defining a singularity useful for the identification of the first tooth (tooth1), or involuntary: loss of the signal on at least one tooth due to a defect on the measurement chain (target, sensor, formatting). It is common to hide the crankshaft signal for a certain time to protect against external disturbances. In particular, in the case of variable reluctance sensors, parasitic detections may occur on the other edge of the signal. With the proposed method, the generation of the masking time is simply obtained by a comparator placed on the output of the down-counter (dcnt iftth).
    [0017] To obtain an absolute position, the engine cycle is reconstructed from the high resolution signal (TOP FTTH). To do this, and when the target consists of m teeth and n singularities, the interval between two singularities defining a sector, the following steps are performed: i. determining the position of at least one missing tooth on the target from the high resolution signal (POSDM); ii. determining the position of at least one sector from the position of this missing tooth (POSSECT); iii. the sector whose position has been determined, as well as the revolution number of the cycle, are identified among the n sectors by means of a synchronization mechanism (SYNC). This mechanism can exploit the signal of a sensor placed on one of the camshafts. The synchronization of the angular position on the engine cycle comprises the following steps (FIG. 1): i. Tooth synchronization As soon as the motor starts rotating, measure the period of each tooth (TTH PERIOD). In order to reject the probability of "falling" on a singularity (SING) during this step, we take into account several consecutive periods. Then, at least one singularity (SING) is detected, that is to say one or more missing teeth. ii. Sector synchronization The singularity is characterized by a longer period between two consecutive teeth (typically, the triple when one has two missing teeth). Once the singularity is detected, we have information on the angular position of a sector, but if there are several sectors on the cycle, which is generally the case, we do not know which sector we are on. At this stage, one is able to provide a valid "sector_pos" information, representing the absolute angular position of the engine on a sector. This information can be used for detection of the target camshaft (AAC). iii. Cycle synchronization Cycle synchronization consists of identifying the number of the sector and revolution on which one is located. For this purpose, additional information is required from the camshaft detection or software control when the engine is not equipped with a camshaft sensor. After cycle synchronization, it is able to provide a valid "cycle_pos" information, representing the absolute angular position of the engine on a cycle. Figure 1 shows the different stages of synchronization: - A: Synchronization phase tooth (Tooth Syncho) - B: Synchronization phase sector (Sector Syncho) - C: Synchronization phase cycle (Syncho cycle) - D: synchronized system High at the bottom of FIG. 1 are represented: TTH: the position of the teeth of the TOP THTH target: the high resolution signal generated according to the invention SECTOR POS: the angular position on a sector SECTOR VALID: a signal indicating to other modules that the signal SECTOR POS is valid and therefore exploitable CAMSHAFT SYN: a signal symbolizing the moment of synchronization cycle CYCLE POS: the angular position on the cycle CYCLE VALID: a signal indicating to other modules that the signal CYCLE POS is valid thus exploitable The symbol R means "representative" and therefore the signal is usable by other modules. The symbol NR means "unrepresentative" and therefore the signal is not exploitable. The engine cycle is reconstructed by means of a cascade of counters each managing an element of the cycle: an engine cycle is constituted by a number of engine revolutions, each of them consisting of a number of sectors, each of which consists of of a number of teeth, each consisting of a number of tooth fractions, each of which consists of a number of sub-fractions of teeth. All these counters are forced to their initial conditions, as long as the first singularity has not been detected during the sector synchronization phase, the detection of the singularity intervening on the detection of the front of the first tooth which follows the singularity . This front serves as an absolute reference to the angular position (the 0 of the angular position).
    [0018] Referring now to FIG. 7: a counter "cnt iffth" is incremented at each pulse "top iftth" delivered by the block "iftth gen". Modulo the interpolated value of ftth, it delivers a pulse "top ftth". A counter "cnt ftth" increments all "top ftth". Modulo nb ftth_per tth (number of tooth fractions per tooth), it delivers a pulse "top-tth" all the teeth.
    [0019] A counter "cnt tth" increments all "top tth". Modulo nb tth_per sec (number of teeth per sector, it delivers a pulse "top dry" all the sectors.) A counter "cnt sect" is incremented all the "dry top" Modulo "nb dry per rev", it delivers a pulse "top rev" all engine revs A "cnt rev" counter is incremented every revolution, it manages the lap number on the engine cycle, a configuration linked to the engine type (4 times / 2 times) and the target type (number of sectors per revolution, number of teeth per sector, number of tooth fractions per tooth) defines the increment limits of these counters, their size is defined by the range of application that is The counter "cnt sec ftth" is incremented at each "top ftth" event, it delivers the angular position of the motor to a sector and is reset at each "top-sect" event. The counter "cnt cycle ftth" is incremented with each event of "top ftth" It delivers the angular position of the engine on a complete cycle and it is reset at every "reset rev" event. Its output represents the instantaneous absolute angular position of the motor. The counter "tth nr" is incremented on each event of "top tth". It delivers the number of the tooth on a complete cycle ("tth number"). It is reset at each "reset rev" event. Released at the moment of detection of the singularity, the counters "cnt iftth", "cnt ftth", "cnt tth" and "cnt sect ftth" make it possible to follow the angular position with respect to a sector. This information, directly provided by "cnt sec ftth" is exploited by a module (CAM) processing the camshaft signal in order to deliver a cycle synchronization.
    [0020] The cycle synchronization applies to the counters "cnt sect", "cnt rev" and "cnt cycle ftth". It is signaled by a pulse "sync cycle" accompanied by the update variables of these counters (dry cycle, rev cycle, cycle cycle ftth). This information is generated by the CAM module following the detection of a particular profile on the camshaft signal (AAC signal) to identify the sector number and the current revolution. The principle of this identification is described below. To synchronize on an engine cycle with more than one sector, additional information is used. This information consists of three signals: a synchronization request signal. a signal indicating which cycle revolution to synchronize. a signal indicating which sector to synchronize. All of these signals can be provided by a system using the AAC signal such as the CAM module, or by another system capable of providing this information following the analysis of particular phenomena on the engine cycle.
    [0021] From the knowledge of the relative position of the camshaft with respect to the angular reference coming from the crankshaft, and by exploiting the sector position ("pos sector ftth"), an analysis window is generated (time or angular ) during which an attempt is made to identify a particular profile of the AAC signal. A profile makes it possible to identify in a unique way on an engine cycle the position on which one is located (sector and revolution). A profile is composed of a series of AAC signal fronts. The detection parameters are multiple. One can for example have a profile of the type: series of n consecutive fronts (amounts or descendants), the first of which is a rising edge; series of n consecutive fronts (amounts or descendants), the first of which is a falling edge; series of n front amounts; series of n descending fronts; state of the signal during the window.
    [0022] The parameters of a profile are: type of detection; number of fronts expected in the window; type of the first edge or state of the expected signal; The sector number corresponding to the profile; The revolution number corresponding to the profile; Depending on the constitution of the crankshaft and camshaft targets, it is possible to define several different profiles. The detection of one of them during the analysis window causes the generation of a synchronization request accompanied by the parameters of angular position (sector and revolution number) of the profile concerned.
    [0023] FIG. 8 shows, on a particular case of AAC signal, the operating principle assuming that there is a crankshaft target having only one sector per engine revolution. An analysis window is defined by its beginning (B) and its end (E) with respect to the angular position of the sector.
    [0024] The configuration of a first profile (profile 0) is: one is interested in all the fronts of the signal, the first is "rising edge" and one has two fronts during the window. The configuration of a second profile (profile 1) is: one is interested in all the fronts of the signal, the first is "rising edge" and one has a front during the window. Other available profiles are not used.
    [0025] The detection of the profile 0 at the end of the first window and the detection of the profile 1 at the end of the second, are two sources of information making it possible to synchronize as soon as possible the complete system on a motor cycle. 3. Continuous determination of the number of the tooth passing in front of the sensor during a stopping phase of the motor This step is represented by the module named "Track Module" in the figures. It is carried out during a stopping phase of the engine, when the determination of the period is no longer possible. In fact, the measurement of the period of the crankshaft teeth is the main source of information for determining the angular position of a target. However, during the stopping phase of the engine, when the engine speed decreases, the tooth period increases to exceed the measurement capabilities of the system causing a desynchronization of the system and forcing a complete synchronization at each engine start. According to the invention, during this phase of absence of value over the period of the teeth, the number of the tooth ("Cur tooth num") passing in front of the sensor is continuously determined by means of a crankshaft effect sensor. lobby. This type of sensor is able to detect each tooth of the crankshaft target, even at very low rotational speeds. This makes it possible to follow the evolution of the angular position during the stopping of the engine. This step can be schematized by a counter which, knowing the characteristics of the crankshaft target, counts the teeth it detects, and is able to provide the number of the current tooth. Initializing the current tooth number After switching on the ECU, it is necessary to initialize the current tooth number managed by the "Track Module" module. To perform this initialization, two strategies can be used: reading in non-volatile memory the data that was saved before the previous power failure; Make a first start using a standard synchronization and communicate to the module "Track Module" the number of the tooth on which it must wedge itself. The default of the first strategy is that it must be able to perform the first initialization (factory initialization) and that there is no guarantee that one does not have a motor rotation while the system is no longer powered, when a mechanical maintenance intervention in particular. The defect of the second strategy is that the first synchronization, after power up, can not be optimized. However, it is fully operational during frequent reboots for Stop & Start applications. Thus, according to the second strategy, at power up, the value of 20 "Cur tooth Num" is not relevant and the module "Track Module" is not able to provide additional information to the module "Target Module". The system thus goes through a complete synchronization phase. Once this is done, the module "Target Module" initializes the value "Cur tooth num" of the module "Track Module". This initialization can be done once, or regularly until the module "Target Module" considers it is operational. This regular update ensures that both modules are in phase. To manage the case where the engine rotates in the opposite direction when, practically stopped, it arrives on a cylinder compression point which tends to turn it in the opposite direction, it is possible to use a mechanical brake mechanism acting on the flywheel 30 during the stopping phase of the engine. This ensures that the motor will not turn in the opposite direction. In this case, the module "Track Module" can work with a standard sensor type effect hall. However, some equipment manufacturers begin to propose sensors providing information on the direction of rotation of the engine in addition to the "tooth" information. Thus, according to one embodiment, a signal (TEETH DIR) indicating the direction is also used. rotation of the sensor to determine the number of the tooth passing in front of the sensor during the stopping phase of the motor.
    [0026] To do this we can use a bidirectional crankshaft sensor. This type of sensor is able to detect each tooth of the crankshaft target, even at very low rotational speeds, but also to indicate the direction of motor rotation. This makes it possible to follow the evolution of the angular position during the stopping of the engine. 4. Determination of the absolute angular position of the target during a restart phase of the engine. This step is carried out during the restart phase of the engine: it is considered that the "Track Module" module is initialized. In order to obtain an absolute position, the engine cycle is reconstructed from the high-resolution signal (TOP FTTH), and synchronization of the angular position is carried out on the engine cycle. Synchronization this time includes the following steps: i. Synchronization tooth As soon as the motor starts to rotate, the period of each tooth 15 (TTH PERIOD) is measured. In order to reject the probability of "falling" on a singularity (SING) during this step, we take into account several consecutive periods. ii. Sector synchronization This step is not necessary because the number of the tooth identified in step 3 is used in the next step. Iii. Cycle synchronization Cycle synchronization consists of identifying the position on the sector, the number of the sector and revolution on which one is located. For this purpose, the number of the tooth identified in step 3 is used. After cycle synchronization, it is possible to provide a valid "cycle_pos" information, representing the absolute angular position of the motor 25 over one cycle. iv. Verifying cycle synchronization The standard synchronization mechanism is used to verify that the fast synchronization step has been performed correctly. In case of non-compliance, it is considered that the fast synchronization has not been correctly performed and a standard synchronization is performed to reset the system. Examples: FIG. 9 shows the gain obtained on the synchronization time with respect to FIG. 1: The overall system is fully synchronized at the end of the tooth synchronization, typically obtained after three crankshaft teeth (phases B and C are no longer needed). Figure 10 shows how, from the value "Cur Tooth num" which continues to evolve during the engine stop phase, the system is able to synchronize completely as soon as it has synchronized tooth The different steps are: X: Stop phase with synchronized system Y: Stop phase with desynchronised system, we continue to follow tooth position Z: Motor stopped A: Synchronization phase tooth D: Synchronized system10
    权利要求:
    Claims (9)
    [0001]
    REVENDICATIONS1. Method for determining the absolute angular position of a crankshaft target of a heat engine, the target having a plurality of teeth, in which at least one signal is acquired by means of a sensor representing the passage of each tooth in front of said sensor in function time, characterized in that: i. during a running phase of the motor: a period of a tooth is determined; increasing the angular resolution of said signal by generating over the period a high resolution signal representing the passage of fractions of the tooth in front of said sensor as a function of time; the absolute angular position is generated from said signal and said period; ii. during a stopping phase of the motor, when the determination of the period is no longer possible, the number of the tooth passing in front of the sensor is continuously determined; and iii. during a restart phase of the motor, said tooth number is used to reduce the cycle synchronization time.
    [0002]
    2. Method according to claim 1, wherein in step i, the absolute angular position is generated by performing the following steps: a. determining the position of at least one missing tooth on the target from said high resolution signal; b. determining the position of at least one sector from the position of said missing tooth; c. the sector of which the position is determined is identified among the sectors of the target, as well as the revolution number of the cycle by means of a counter synchronization mechanism.
    [0003]
    3. Method according to one of the preceding claims, wherein in step i, the period of the tooth is determined, from a period of the previous tooth or from an internal measurement, or from a information from an external device.
    [0004]
    4. Method according to one of the preceding claims, wherein the number of the identified tooth is initialized by determining the position of at least one missing tooth on the target from said high resolution signal during a first start phase of the engine.
    [0005]
    5. Method according to one of the preceding claims, wherein in step iii, the absolute angular position is generated, by performing the following steps: a- a synchronization is done dent13- one identifies the sector number and revolution of the cycle from the number of the tooth identified in step ii.
    [0006]
    The method of claim 5 wherein prior to step a: determining the position of at least one missing tooth on the target from said high resolution signal, and deriving a second number of teeth therefrom. compare to the number of the tooth identified in step ii; if said tooth numbers are not identical, the second tooth number is used, then the value of the current tooth number is initialized.
    [0007]
    7. Method according to one of the preceding claims, wherein is further used a signal indicating the direction of rotation of the sensor to determine the number of the tooth passing in front of the sensor during the stopping phase of the engine.
    [0008]
    The method according to one of the preceding claims, wherein the angular resolution of said signal is increased by interpolating the signal on each tooth period by means of the Bresenham algorithm.
    [0009]
    9. Method according to one of the preceding claims, wherein the acquired signal is the signal measured in real time by a crank sensor hall effect.
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    同族专利:
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    FR3018856B1|2016-07-08|
    US9658082B2|2017-05-23|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    DE4230616A1|1992-09-12|1994-03-17|Bosch Gmbh Robert|Device for recognizing the position of at least one shaft having a reference mark|
    US6499342B1|2000-09-05|2002-12-31|Ford Global Technologies, Inc.|Method of determining the stopping position of an internal combustion engine|
    DE10237221A1|2001-08-22|2003-03-27|Avl List Gmbh|Method and device for providing a crank angle-based signal method|
    DE102004049578A1|2004-10-12|2006-04-13|Robert Bosch Gmbh|Starting method for internal combustion engine involves regulating direction and angle of rotation of crankshaft based on signal levels stored in non-volatile memory|
    FR2937684A1|2008-10-29|2010-04-30|Continental Automotive France|False teeth period determining method for crankshaft of internal combustion engine, involves estimating period of false teeth by adding corrective term function of difference between periods of two row teeth, to period of one of row teeth|US20170299467A1|2014-10-23|2017-10-19|Scania Cv Ab|Device for detecting speed of a rotatable element, method and vehicle|JPS5436961A|1977-08-29|1979-03-19|Nissan Motor|Angleeoffrotation detector|
    US4235101A|1978-11-29|1980-11-25|The Bendix Corporation|Adjustable engine crankshaft position sensor with preadvance timing signal capability and method of varying engine timing|
    US4409548A|1981-07-06|1983-10-11|Ford Motor Company|Piezoelectric apparatus for generating electrically distinguishable bipolar signals|
    US4814704A|1987-04-08|1989-03-21|Motorola, Inc.|Rotor position indicator with correction for apparant acceleration and deceleration|
    US4782692A|1987-09-14|1988-11-08|General Motors Corporation|Engine crankshaft position sensor|
    AUPN667595A0|1995-11-20|1995-12-14|Orbital Engine Company Proprietary Limited|Electronic position and speed sensing device|
    US6172500B1|1998-06-23|2001-01-09|Honeywell International Inc|Target design for geartooth sensor with minimal number of unique segments combined in nonrepeating fashion|
    US6752009B2|2001-08-03|2004-06-22|General Motors Corporation|Encoded crank position sensor|US9973195B2|2015-04-08|2018-05-15|Infineon Technologies Ag|Local phase detection in realigned oscillator|
    FR3045725A1|2015-12-17|2017-06-23|Continental Automotive France|EXACT SYNCHRONIZATION METHOD|
    US10184860B2|2016-04-08|2019-01-22|Infineon Technologies Ag|Control system for power train control|
    JP2020172890A|2019-04-10|2020-10-22|トヨタ自動車株式会社|Control device of internal combustion engine|
    CN111775958B|2020-06-30|2021-09-03|东风商用车有限公司|Method for diagnosing loss of crankshaft signal and camshaft signal of engine|
    法律状态:
    2015-01-22| PLFP| Fee payment|Year of fee payment: 2 |
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    2016-08-05| TQ| Partial transmission of property|Owner name: IFP ENERGIES NOUVELLES, FR Effective date: 20160630 Owner name: SILICON MOBILITY, FR Effective date: 20160630 Owner name: SCALEO CHIP, FR Effective date: 20160630 |
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    优先权:
    申请号 | 申请日 | 专利标题
    FR1452384A|FR3018856B1|2014-03-21|2014-03-21|METHOD FOR DETERMINING THE INSTANTANEOUS ANGULAR POSITION OF AN OPTIMIZED CRANKSCRIPT TARGET FOR STARTING THE ENGINE|FR1452384A| FR3018856B1|2014-03-21|2014-03-21|METHOD FOR DETERMINING THE INSTANTANEOUS ANGULAR POSITION OF AN OPTIMIZED CRANKSCRIPT TARGET FOR STARTING THE ENGINE|
    US14/660,238| US9658082B2|2014-03-21|2015-03-17|Method of determining the instantaneous angular position of a crankshaft target optimized for starting the engine|
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