FR3072145A1 - METHOD FOR COMPENSATING ACYCLISMS OF A THERMAL MOTOR USING A ROTATING ELECTRIC MACHINE - Google Patents

Abstract

The invention relates mainly to a method for compensating the acyclisms of a motor vehicle engine (12) comprising: - a step of measuring an angular position of the shaft (17.3) or the rotor (17.2) by means of a sensor (27) implanted between the mechanical damper (20) and the gearbox (13) at the location where the rotor (17.2) of the rotary electric machine (17) is arranged, - a determination step , from the measured angular position of the shaft (17.3) or the rotor (17.2), a torque variation related to the acyclism of the heat engine, - a step of subtraction or addition, depending on the sign of this torque variation, of this torque variation at a reference torque setpoint (Cref) of the rotating electrical machine (17), to determine a control torque setpoint (Cref), a control step of the rotary electric machine (17) for obtaining the control torque setpoint.

Description

METHOD FOR COMPENSATING ACYCLISMS OF A HEAT ENGINE BY MEANS OF A ROTATING ELECTRIC MACHINE

The present invention relates to a method of compensating for acyclisms of the heat engine by means of a rotary electric machine.

In a manner known per se, a motor vehicle traction chain comprises a heat engine coupled to a gearbox by means of a clutch. The gearbox is mechanically connected to the wheels via a differential. Generally, the engine crankshaft is connected to a mechanical damper and then to the clutch to transmit energy to the wheels through the gearbox.

In addition, a rotating electric machine can be installed in the traction chain to improve the vehicle's energy balance. This electric machine is capable of operating in engine mode to provide traction for the vehicle alone or in combination with the heat engine to provide traction assistance. This machine is also capable of operating in generator mode to supply energy to the vehicle battery and / or to the loads coupled to the electrical network.

The heat engine, when running, exhibits torque fluctuations due to explosions and compression of the fuel in the cylinders. These torque fluctuations result in significant variations in speed which are damped by the inertia present on the shaft of the heat engine. Nevertheless, the variations remain significant, causing vibrations and design constraints for the mechanical parts, despite the presence of the damper placed on the crankshaft of the heat engine.

The object of the invention is to overcome, at least in part, this drawback by taking advantage of the presence of the rotating electric machine placed downstream of the mechanical damper.

To this end, the subject of the invention is a method of compensating for acyclisms in a heat engine of a motor vehicle, the heat engine belonging to a traction chain comprising:

- a mechanical shock absorber,

- a rotating electric machine comprising a rotor mounted on a shaft and a stator,

- at least one clutch, and

- a gearbox, characterized in that said method comprises:

a step of measuring an angular position of the shaft or of the rotor by means of a sensor located between the mechanical damper and the gearbox at the place where the rotor of the rotary electric machine is arranged,

a step of determining, from the measured angular position of the shaft or of the rotor, a variation in torque linked to the acyclism of the heat engine,

a step of subtraction or addition, as a function of the sign of this variation in torque, of this variation in torque to a reference torque setpoint of the rotary electric machine, in order to determine a control torque setpoint,

- a step of piloting the rotating electrical machine to obtain the command torque command.

According to one implementation, the step of determining the torque variation comprises a step of selecting the torque variations, then a step of synchronous demodulation of a speed variation linked to the acyclism to obtain a continuous component of the acyclism by filtering the high image frequency.

According to one implementation, the step of determining the torque variation also comprises a step of slaving the DC component to a reference value, for example equal to zero.

According to one implementation, said method comprises a step of correcting a component obtained after slaving.

According to one implementation, the step of determining the torque variation comprises a step of re-modulation of the DC component, before performing the step of subtracting or adding the signal obtained to the torque setpoint of reference.

According to one implementation, said method further comprises an optional phase correction and / or gain correction of the signal obtained after remodulation.

According to one implementation, the step of determining the torque variation linked to the acyclism includes a step of transforming the measured angular position of the rotor or of the shaft by a transformation system operating at K times the speed of rotation of the rotor or of the shaft to obtain two quadrature output signals of which only the DC component is preserved by filtering, K being equal to the number of explosions in the cylinders per revolution of the crankshaft.

According to one implementation, the transformation system implements a transformation of temporal references, for example a transformation of Park or sin / cos.

According to one implementation, said method includes a step of filtering each output signal from the transformation system to isolate a DC component.

According to one implementation, said method comprises a step of slaving each continuous component to a reference value, for example equal to zero.

According to one implementation, said method comprises a step of correcting each filtered signal, in particular by means of a corrector, for example of the Proportional or Proportional-lntégral type.

According to one implementation, said method comprises a step of reverse transformation of time marks for each filtered signal, the signal coming from a sum or addition of the signals of the inverse transform operation being added or subtracted from the torque setpoint of reference.

According to one implementation, said method comprises an optional preliminary step of phase and / or gain correction of the signal resulting from the combination of the signals of the inverse transform operation.

According to one implementation, the steps of the method, in particular the steps of transformation, filtering, servo-control and reverse transformation, are implemented in parallel for different harmonics of the couple linked to acyclism,

and said method also comprises a step of sum or addition of the signals processed for these different harmonics to obtain a resulting signal,

- Said resulting signal being added to or subtracted from the reference torque setpoint.

According to one implementation, the rotary electric machine is disposed between the clutch and the heat engine.

According to one implementation, the rotary electric machine is disposed between two clutches so as to allow an electric rolling mode and a thermal rolling mode of the motor vehicle.

The subject of the invention is also a system for compensating acyclisms of a heat engine of a motor vehicle, the heat engine belonging to a traction chain comprising:

- a mechanical shock absorber,

- a rotating electric machine comprising a rotor mounted on a shaft and a stator,

- at least one clutch, and

- a gearbox, characterized in that said method comprises:

- a sensor for measuring an angular position of the shaft or of the rotor installed between the mechanical damper and the gearbox at the place where the rotor of the rotary electric machine is arranged,

means for determining, from the measured angular position of the shaft or of the rotor, a variation in torque linked to the acyclism of the heat engine,

means of subtraction or addition, as a function of the sign of this variation in torque, of this variation in torque to a reference torque setpoint of the rotary electric machine, to determine a control torque setpoint,

- means for controlling the rotating electric machine to obtain the command torque command.

The invention will be better understood on reading the description which follows and on examining the figures which accompany it. These figures are given only by way of illustration but in no way limit the invention.

Figures 1a and 1b are schematic representations illustrating two embodiments of a traction chain for a motor vehicle with which is implemented the method of compensating acyclisms of the heat engine according to the present invention;

FIG. 2a is a schematic representation of a first embodiment of a system for compensating acyclisms of the heat engine according to the present invention;

FIG. 2b is a diagram of the steps of the method according to the invention implemented with the acyclism compensation system of FIG. 2a;

FIG. 3a is a schematic representation of a second embodiment of a functional block according to the invention making it possible to determine the variations in torque linked to the acyclism of the heat engine;

FIG. 3b is a diagram of the steps of the method according to the invention implemented with the acyclism compensation system according to the invention integrating the functional block of FIG. 3a;

FIGS. 4a and 4b illustrate a parallel implementation of the method according to the invention for different harmonics of the torque linked to the acyclism respectively without and with the use of a pendular device for damping acyclisms.

Identical, similar, or analogous elements retain the same reference from one figure to another.

FIGS. 1a and 1b show a traction chain 10 installed on a train 11 of a motor vehicle.

This traction chain 10 comprises a heat engine 12 and a gearbox 13 provided with at least one input shaft 13.1 and an output shaft 13.2 connected to the wheels by means of a differential 16. A clutch K1 is interposed between the heat engine 12 and the input shaft 13.1 of the gearbox 13.

A rotary electrical machine 17 of reversible type is disposed between the clutch K1 and the heat engine 12. More specifically, this electrical machine 17 is disposed between the clutch K1 and a mechanical damper 20 mounted on the crankshaft of the heat engine 12.

The electric machine 17 is able to operate in a generator mode during a regenerative braking phase delivering current on the network for example to recharge a battery (not shown) as well as in a motor mode to assist the heat engine 12 and, if necessary with the KO clutch open to ensure electric rolling of the vehicle, as shown in FIG. 1 b.

Advantageously, as shown in FIG. 2a, the mechanical damper 20, the electric machine 17, as well as the clutch K1 are contained in the same housing 21.

As shown in FIGS. 1a and 1b, an optional rotary electrical machine 24 can be coupled to the heat engine 12 via the front face, on the accessory front belt. The movement transmission device 25 between the heat engine 12 and the electric machine 24 may for example comprise a belt cooperating with pulleys carried respectively by the crankshaft and the shaft of the machine 24. This electric machine 24, commonly called alternately starter, is capable of operating in a generator mode to recharge the vehicle battery as well as in an engine mode to ensure starting of the thermal engine 12 while the vehicle is stopped or during a transition from a mode of electric driving towards a thermal driving mode.

The electric machine 17 has an operating voltage between 48 Volts and 300 Volts. The electric machine 24 has an operating voltage between 12 Volts and 48 Volts. According to one embodiment, the electric machine 17 is of the 48 Volts or 300 Volts type, and the electric machine 24 is of the 12 Volts or 48 Volts type. The electrical machines 17, 24 may respectively, for example, be machines of the synchronous type with permanent magnets, and / or synchronous with a wound rotor.

In the embodiment of Figure 1b, use is made of the second clutch KO. The electric machine 17 is mounted between the first clutch K1 and the second clutch KO. Thus, in an electrical operating mode, the clutch KO is open while K1 is closed. In a thermal operating mode, the two clutches KO and K1 are closed.

There is described below, with reference to FIGS. 2a and 2b, a first implementation of the system and of the method for compensating for acyclisms of the heat engine 12 according to the invention.

A sensor 27 ensures, in a step 100, a measurement Mes_pos of an angular position of the shaft 17.3 or of the rotor 17.2. The sensor 27 is installed between the mechanical damper 20 and the gearbox 13 at the place where the rotor 17.2 of the electric machine 17 is arranged.

In a step 101, the functional block 28 then determines, from the measured angular position Mes_pos of the shaft 17.3 or of the rotor 17.2, the variation in torque linked to the acyclism of the heat engine 12.

To this end, the module 29 ensures, in a step 102, a selection of the torque variations then a synchronous demodulation of a speed variation linked to the acyclism to obtain a continuous component of the acyclism by filtering a high image frequency using filter 30.

In a step 103, the module 31 enslaves the DC component to a reference value R, for example equal to zero.

In a step 104, the component originating from the module 31 is corrected by a corrector module 32, for example of the Proportional-lntégral type.

The module 33 performs, in a step 105, a re-modulation of the DC component.

In a step 106, the signal obtained after re-modulation can be corrected in phase and / or in gain respectively via the modules 35.1 and 35.2.

In a step 107, this variation in torque is subtracted or added, depending on its sign, using a module 34, to a reference torque setpoint Cref of the rotary electric machine 17, to determine a setpoint of Cref control torque which incorporates the torque variation to be applied to compensate for the acyclism of the heat engine 12.

The rotary electrical machine 17 is then controlled, in step 108, to obtain the Cref command torque setpoint.

To this end, the Cref command torque setpoint is applied in a conventional torque control chain 36 of the electric machine 17. This chain 36 includes a comparator 37 for comparing the Cref input command torque signal with the output signal of a model 38 of the rotary electrical machine 17. This model 38 is related to power modules 39 of a transistor rectifier bridge also having an inverter function for injecting currents into the phase windings of the stator 17.1 in order to obtain the desired command torque setpoint Cref on the shaft 17.3 on which the rotor 17.2 of the machine is mounted 17. The output signal from the comparator 37 is advantageously corrected using a corrector 42, for example of the PI (Proportional-lntégral) type.

There is described below, with reference to FIGS. 3a and 3b, a second implementation of the system and of the method for compensating for acyclisms of the heat engine 12 according to the invention.

As before, a sensor 27 ensures, in a step 200, a measurement Mes_pos of an angular position of the shaft 17.3 or of the rotor 17.2. The sensor 27 is located between the mechanical damper 20 and the gearbox 13 at the place where the rotor 17.2 of the electric machine is arranged.

In a step 201, the functional block 28 then determines, from the measured angular position Mes_pos of the shaft 17.3 or of the rotor 17.2, the variation in torque linked to the acyclism of the heat engine 12.

To this end, in a step 202, the system 45 ensures a transformation of the measured angular position of the rotor 17.2 or of the shaft 17.3 by a transformation system operating at K times the speed of rotation Θ of the rotor 17.2 or of the tree 17.3 to obtain two output signals xD and xQ in quadrature of which only the DC component is preserved by filtering. It is specified that K is equal to the number of explosions in the cylinders per revolution of the crankshaft.

In other words, K corresponds to the acyclism present on the crankshaft of the heat engine 12. We will use K = 2 for a 4-cylinder heat engine, K = 1.5 for a 3-cylinder heat engine, and K = 3 for a heat engine with 6 cylinders, etc.

Advantageously, the transformation system 45 implements a transformation of time marks, for example a Park or sin / cos transformation.

In a step 203, a module 46 filters each output signal from the transformation system 45 to isolate a DC component.

In a step 204, the module 47 enslaves each continuous component to a reference value R, for example equal to zero.

In a step 205, each filtered signal is corrected, in particular by means of a corrector 48, for example of the proportional or proportional integral type.

In a step 206, the system 49 ensures a reverse transformation of time marks for each filtered signal.

In a step 207, the module 50 performs a sum or addition of the signals of the inverse transform operation to obtain a signal corresponding to the variation in torque.

Optionally, in a step 208, the signal resulting from the combination of the signals of the inverse transform operation can be corrected in phase and / or in gain respectively via the modules 35.1 and 35.2 (cf. FIG. 2a).

In a step 209, the signal corresponding to the torque variation is subtracted or added, depending on its sign, using a module 34, to a reference torque setpoint Cref of the rotary electric machine 17, for determine a Cref command torque setpoint which incorporates the torque variation to be applied to compensate for the acyclism of the heat engine 12.

The rotary electrical machine 17 is then controlled, in step 210, to obtain the Cref command torque setpoint.

To this end, the Cref command torque setpoint is applied in a conventional torque control chain 36 of the electric machine 17. This chain 36 includes a comparator 37 for comparing the Cref input command torque signal with the output signal of a model 38 of the rotary electrical machine 17. This model 38 is related to power modules 39 of a transistor rectifier bridge also having an inverter function for injecting currents into the phase windings of the stator 17.1 in order to obtain the desired command torque setpoint Cref on the shaft 17.3 on which the rotor 17.2 of the machine is mounted 17. The comparator output signal 37 is advantageously corrected using a corrector 42, for example of the PI (Proportional-lntégral) type.

As illustrated in FIG. 4a, the steps of the method, in particular the steps of transformation, filtering, servo-control and reverse transformation carried out by the functional blocks 28, are implemented in parallel for different harmonics of the torque linked to the irregular. To this end, the corresponding transformation system 45 operates at 2.N.K times the speed of rotation Θ of the rotor 17.2 or of the shaft 17.3, N being the rank of the harmonic processed.

The module 50 then provides a sum or addition of the signals processed for these different harmonics to obtain a resulting signal.

The resulting signal is added to or subtracted from the reference torque setpoint, as previously explained.

In the case where a pendulum device is used to filter the acyclisms 5 of the heat engine, it is possible to remove the block ensuring the filtering of the harmonics of rank 1 (already filtered by the pendulum device), as illustrated by the figure 4b.

Of course, the foregoing description has been given by way of example only and does not limit the scope of the invention, from which one would not depart by replacing the various elements with any other equivalent.

Furthermore, the various features, variants, and / or embodiments of the present invention can be combined with one another in various combinations, insofar as they are not incompatible or mutually exclusive of one another.

Claims (11)

1. Method for compensating acyclisms of a heat engine (12) of a motor vehicle, the heat engine (12) belonging to a traction chain (10) comprising: - a mechanical damper (20), - a rotary electrical machine (17) comprising a rotor (17.2) mounted on a shaft (17.3) and a stator (17.1), - at least one clutch (KO, K1), and - a gearbox (13), characterized in that said method comprises: a step of measuring (100, 200) an angular position of the shaft (17.3) or of the rotor (17.2) by means of a sensor (27) installed between the mechanical damper (20) and the gearbox gears (13) at the place where the rotor (17.2) of the rotary electric machine (17) is arranged, a step of determining (101, 201), from the angular position measured (Mes_pos) of the shaft (17.3) or of the rotor (17.2), of a variation in torque linked to the acyclism of the heat engine, a step of subtraction or addition (107, 209), as a function of the sign of this variation in torque, of this variation in torque to a reference torque setpoint (Cref) of the rotary electric machine (17), for determine a command torque setpoint (Cref), - A piloting step (108, 210) of the rotary electric machine (17) to obtain the command torque command. 2. Method according to claim 1, characterized in that the step of determining (101) the torque variation comprises a step (102) of selecting the torque variations, then a step of synchronous demodulation of a speed variation linked to acyclism to obtain a continuous component of acyclism by filtering a high image frequency. 3. Method according to claim 2, characterized in that the step of determining (101) of the torque variation further comprises a step (103) of slaving of the DC component to a reference value, for example equal to zero. 4. Method according to claim 3, characterized in that it comprises a correction step (104) of a component obtained after slaving. 5. Method according to claim 3 or 4, characterized in that the step of determining (101) of the torque variation comprises a step of remodulation (105) of the continuous component, before carrying out the step of subtraction or adding the signal obtained to the reference torque setpoint. 6. Method according to claim 5, characterized in that it further comprises an optional step (106) of phase correction and / or gain of the signal obtained after re-modulation. 7. Method according to claim 1, characterized in that the step of determining (201) of the torque variation linked to the acyclism includes a step (202) of transformation of the measured angular position of the rotor or of the shaft by a transformation system (45) operating at K times the rotational speed of the rotor (17.2) or of the shaft (17.3) to obtain two quadrature output signals (xD, xQ) of which only the continuous component is kept by filtering, K being equal to the number of explosions in the cylinders per revolution of the crankshaft. 8. Method according to any one of claims 1 to 7, characterized in that the rotary electric machine (17) is disposed between the clutch (K1) and the heat engine. 9. Method according to any one of claims 1 to 7, characterized in that the rotary electric machine (17) is arranged between two clutches (KO, K1) so as to allow an electric rolling mode and a thermal rolling mode of the motor vehicle. 10. A system for compensating acyclisms of a heat engine (12) of a motor vehicle, the heat engine (12) belonging to a traction chain (10) comprising: - a mechanical damper (20), - a rotary electrical machine (17) comprising a rotor (17.2) mounted on a shaft (17.3) and a stator (17.1), - at least one clutch (KO, K1), and - a gearbox (13), 5 characterized in that said method comprises: - a sensor (27) for measuring (100, 200) an angular position of the shaft (17.3) or of the rotor (17.2) installed between the mechanical damper (20) and the gearbox (13) at the place where the rotor (17.2) of the rotary electric machine (17) is arranged, îo - determination means (29-33; 45-49), from the measured angular position (Mes_pos) of the shaft ( 17.3) or of the rotor (17.2), of a torque variation linked to the acyclism of the heat engine, - Subtraction or addition means (34), as a function of the sign of this variation in torque, of this variation in torque at a setpoint of 15 reference torque (Cref) of the rotary electrical machine (17), to determine a command torque setpoint (Cref), - control means (36, 37, 38, 39, 42) of the rotary electric machine (17) to obtain the command torque command (Cref).