FR3006651A1 - METHOD FOR TORQUE CONTROL OF A MOTOR VEHICLE MOTOR DURING AN ANTI-SKATING REGULATION - Google Patents

Abstract

The invention relates mainly to a method for controlling a motor vehicle engine by a torque (Cm) determined in particular from a preventive torque (Cp) obtained by filtering a reference torque (Cc) translating a desire to accelerate the driver. According to the invention, in the case of an anti-slip regulation phase during which an anti-slip pair (Casr) takes precedence over the preventive torque (Cp) so as to limit a loss of adhesion of driving wheels, said method comprises the step of taking into account said antiskid torque (Casr) at the end of said antiskid regulation phase to develop said preventive torque (Cp) following a deceleration request of the vehicle from the driver.

Description

The invention relates to a method for controlling a motor vehicle engine in a phase during a single phase of a motor vehicle engine during a phase. anti-skid control system. The invention applies to the field of control control of vehicles equipped with a gasoline or diesel powertrain (GMP) with a manual gearbox (BVM), automated (BVA), controlled (BVMP) or double clutch (DCT). Such vehicles are equipped with a computer to automatically adapt the operating point of each of the vehicle components, in particular the engine, to meet the will of the driver in terms of requested torque. To obtain optimum driving pleasure, the computer uses two types of torque filtering requested by the driver using a preventive approval module and a curative approval module. The preventive approval module thus ensures a filtering of the target torque corresponding to the will of the driver in order to pass the engine games by limiting the jolts of the drive chain as much as possible. The term "engine games" is the phenomenon of torsion of the transmission elements between the moment when the heat engine lands on its holds and the moment when the engine drives the vehicle. The engine sets thus correspond to the applied torque for which neither the engine nor the wheel train with each other during a transient phase of acceleration. The curative amenity module can mitigate any oscillations of the engine speed resulting from the passage of engine games. For this purpose, it generates a torque in phase opposition with the engine speed. During a deceleration, the preventive approval ensures the filtering during the passage of the engine games according to two thresholds called threshold of entry and exit threshold of the games. However, during an anti-slip regulation phase during which an anti-slip pair called ASR torque for "Acceleration Slip Regulation" is generated so as to limit a loss of traction of the wheels motor control is sequenced in such a way that the Casr anti-slip pair has priority and imposes its engine torque in order to secure the vehicle. Thus, as seen in Figure 1, when the control phase is triggered at time t0, the engine torque Cm shown in broken lines follows the Casr torque setpoint. Once the driver decelerates at time t1 (the setpoint torque Cc is then 0), there is an observable TCAN delay between times t1 and t2 of the order of a few tens of milliseconds corresponding to the time that the corrector electronic trajectory receives the information position zero acceleration pedal and returns a torque of traction control Casr null. Thus, after this delay TCAN, the regulation phase being completed, the preventive pair Cp is applied again and this without transition. However, the preventive approval being calibrated in a manner so as to avoid pumping the turbo or to cover the discharge noise of the discharge valve for example, the preventive torque Cp is often greater than the torque of Casr slip in regulation output. As a result, the transition of the engine torque Cm on the preventive torque Cp will tend to cause a flight engine speed Wm after the time t2 may cause a sliding of the wheels, which represents a security risk. The invention aims to effectively overcome this disadvantage by providing a method of controlling a thermal engine of a motor vehicle by a particular torque from a preventive torque obtained by filtering a torque setpoint translating a desire for acceleration of the driver, characterized in that, in the event of an anti-slip regulation phase during which an anti-slip pair has priority over the preventive torque so as to limit a loss of traction wheel adhesion, said method comprises the step of taking into account said anti-slip pair at the end of said antiskid regulation phase to develop said preventive torque following a request for deceleration of the vehicle of the driver's share. The invention thus ensures the continuity of the engine torque and allows a fast and safe deceleration of the vehicle from the release of the foot of the accelerator. In other words, the invention avoids degrading driving pleasure by untimely acceleration and thus to ensure safety on board the vehicle. It is also noted that the invention does not require any additional cost insofar as its implementation relies on a software adaptation of existing computers. According to one embodiment, the method comprises the step of resetting the preventive torque to a value of the antiskid torque at the end of the antiskid regulation phase. Preferably, the implementation of said method is authorized if at least one of these three activation conditions is validated: the antiskid torque is less than a calibrated threshold for confirmation of entry into the anti-skid regulation phase, - the position of the accelerator pedal is less than a calibrated threshold for confirmation that the driver is raised, - a setpoint torque has reached a couple of engine losses to a calibrated deviation for confirmation of a deceleration request. According to one embodiment, the threshold of the antiskid torque is of the order of 20 N.m. In one implementation, a confirmation delay of the activation conditions is inserted to establish a communication between a motor computer and an electronic trajectory corrector computer. According to one embodiment, the method comprises the step of taking the minimum between the preventive torque and the anti-slip pair to ensure a priority to the anti-slip pair during the control phase of the invention. traction. According to one embodiment, out of anti-slip regulation phase, the anti-slip pair has a high value so as not to have priority over the preventive torque. According to one embodiment, the target torque is determined from an engine speed, a gear ratio engaged, and a position of an acceleration pedal actuated by the driver. According to one embodiment, the torque for the control of the heat engine is determined also taking into account a correction torque in phase opposition with the engine speed to mitigate a possible oscillation regime. The invention will be better understood on reading the description which follows and the examination of the figures that accompany it. These figures are given for illustrative but not limiting of the invention. FIG. 1, already described, shows graphical representations of the various torques and the engine speed that can be observed during the implementation of a method according to the state of the art; [0023] Figure 2 shows a schematic representation of a management system of the torque control of a heat engine according to the invention; Figure 3 shows a diagram of the steps of the torque control process of a heat engine during an antiskid phase according to the invention implemented with the system of Figure 2; Figure 4 shows graphical representations of the various torques and engine speed observable during the implementation of the method according to the invention. Identical, similar or similar elements retain the same reference from one figure to another. Figure 2 shows a system 1 for managing the torque control of a heat engine according to the invention. This system 1 comprises a module 2 for interpreting the driver's will, as well as a module 3 for preventive approval, and an electronic trajectory corrector 4 of the ESP type (for "Electronic Stability Program" in English) in relation to on the one hand with the module 3 of preventive approval and on the other hand with a module 5 of curative approval able to generate the final torque Cm sent to the engine. The system 1 is integrated in a motor computer with the exception of the electronic trajectory controller 4 integrated in another computer. More specifically, with reference to Figure 3, the module 2 determines in a step 101 a torque Cc, said torque setpoint, from the engine speed Wm, gear ratio R engaged, and the position P of the accelerator pedal operated by the driver to retranscribe the driver's will. The setpoint torque Cc is then filtered in a step 102 using the preventive authorization module 3 to generate a preventive torque Cp making it possible to limit the jolts in a zone of passage of the engine games to the maximum extent. . The electronic trajectory controller 4 then coordinates the preventive torque Cp with the anti-slip pair Casr in a step 103 by taking the minimum of the two pairs to secure the vehicle. This coordinated pair is translated, in a step 104, into a given torque Ci taking into account the engine losses. Thus, the torque indicated is equal to the sum of the coordinated torque and a torque Cpm of motor losses: Ci = min (Cp, Casr) + Cpm [0031] The torque Cpm of motor losses is the torque required for the motor to make advance the vehicle. This torque Cpm of engine losses takes into account in particular the engine friction as well as the losses related to accessories such as the alternator. The curative amenity module 5 monitors the evolution of the engine speed Wm and attenuates the possible speed oscillation by generating, in a step 105, a correction torque Ccor in phase opposition with the engine speed Wm. [5] 0033] The resulting torque is the final torque Cm sent to the engine in a step 106 and converted into control of the various members, such as for example a quantity of fuel to be injected into the cylinders of the engine. As seen in Figure 4, when anti-slip regulation is activated at time tO, the engine torque Cm shown in broken lines follows the Casr torque setpoint during step 201 Once the driver decelerates at time t1 by releasing the accelerator pedal (the setpoint torque Cc then becomes zero), there is a TCAN delay between times t1 and t2 of the order of a few tens of seconds. milliseconds corresponding to the time that the electronic trajectory corrector 4 receives in particular the zero acceleration pedal position information by the engine computer and returns a zero Casr torque. Once the foot survey detected and the TCAN delay taken into account, the preventive pair Cp is reset in a step 202 at time t2 on the value of the anti-slip pair Casr (see zone Z on Figure 4) so that the engine torque Cm continues to decrease gradually after the antiskid regulation phase. The invention thus enables the vehicle to decelerate as soon as the foot of the accelerator pedal is released, which avoids the jump of the preventive torque Cp and the corresponding flight of the engine speed Wm. A gain G in brio and in safety compared to the method of the state of the art generating the preventive torque shown in phantom. To avoid the risk of false detections, the strategy is activated, that is to say that the preventive torque Cp will be correlated to the Casr control torque, when the following three activation conditions are validated in the step 200: - The torque Casr is lower than a calibrated threshold If for confirmation in the entry of the anti-skid regulation phase. In fact, on dry ground or more generally outside anti-slip regulation phase, the Casr couple has a high value so as not to be a priority in the torque structure. When the electronic trajectory controller 4 detects a wheel slip, the Casr torque becomes a priority and drives the engine with a low torque, which is lower than the previously calibrated threshold of, for example, approximately 20N.m. - The P position of the accelerator pedal is less than a calibrated threshold S2 to confirm that the driver is raised foot. - The setpoint torque Cc has reached the motor loss pair within a calibrated range to confirm that the driver is requesting deceleration. Since the trajectory correction function is embedded in a computer other than the engine computer, a confirmation delay of the activation conditions is inserted to allow communication between the computers and to avoid loss of tasks. . This delay corresponds to the TCAN delay associated with the analog / digital conversion and the transmission of the various parameters (accelerator pedal position and values of the various torques) from the engine computer to the electronic trajectory corrector 4. [0038] It is clear that the person skilled in the art may make modifications to the management system of the torque control of a heat engine and the corresponding motor control method previously described without departing from the scope of the invention. Thus, in particular, it will be possible to activate the control strategy of the engine if at least one of the three aforementioned conditions is verified.

Claims (9)

1. A method for controlling an engine of a motor vehicle by a torque (Cm) determined in particular from a preventive torque (Cp) obtained by filtering a set torque (Cc) reflecting a desire to driver acceleration, characterized in that, in the case of an anti-slip regulation phase (201) in which an anti-slip pair (Casr) takes precedence over the preventive torque (Cp) so as to to limit a loss of adhesion of driving wheels, said method comprises the step of taking into account said antiskid torque (Casr) at the end of said antiskid regulation phase to develop said preventive torque (Cp ) following a request for deceleration of the vehicle by the driver. 2. Method according to claim 1, characterized in that it comprises the step of resetting the preventive torque (Cp) to a value of the antiskid torque (Casr) at the end of the anti-slip regulation phase. -skating. 3. Method according to claim 1 or 2, characterized in that its implementation is authorized if at least one of these three activation conditions is validated (200): - the anti-slip pair (Casr) is lower at a calibrated threshold (S1) for confirmation of the entry into the antiskid regulation phase, - the position (P) of the accelerator pedal is less than a calibrated threshold (S2) for confirmation that the driver is a raised leg, - a setpoint torque (Cc) has reached a couple of motor losses (Cpm) to a calibrated deviation for confirmation of a deceleration request. 4. Method according to one of claims 1 to 3, characterized in that the threshold of the antiskid torque (S1) is of the order of 20 N.m. 5. Method according to one of claims 1 to 4, characterized in that a timer (TCAN) confirming the activation conditions is inserted to establish a communication between a motor computer and an electronic trajectory corrector calculator (4). ). 6. Method according to one of claims 1 to 5, characterized in that it comprises the step of taking the minimum between the preventive torque (Cp) and the anti-slip pair (Casr) to ensure a priority to anti-skid torque (Casr) during the anti-skid regulation phase. 7. The method as claimed in claim 6, characterized in that, outside the anti-slip regulation phase, the anti-slip pair (Casr) has a high value so as not to have priority over the preventive torque ( Pc). 8. Method according to one of claims 1 to 7, characterized in that the setpoint torque (Cc) is determined from an engine speed (Wm), gear ratio (R) engaged, and a position (P) of an accelerator pedal actuated by the driver. 9. Method according to one of claims 1 to 8, characterized in that the torque (Cm) for the control of the engine is determined also taking into account a correction torque (Ccor) in opposition to the phase motor (Wm) for attenuating an eventual oscillation.