CN111094041A

CN111094041A - Method and system for compensating irregularities of a heat engine by means of a rotating electrical machine

Info

Publication number: CN111094041A
Application number: CN201880060044.XA
Authority: CN
Inventors: P.蒂塞兰德; A.施米特; J-C.马特; M.保罗; J.劳帕; M.马扎林
Original assignee: Valeo Equipements Electriques Moteur SAS
Current assignee: Valeo Equipements Electriques Moteur SAS
Priority date: 2017-08-04
Filing date: 2018-07-27
Publication date: 2020-05-01
Also published as: EP3661783A1; FR3069829B1; FR3069829A1; WO2019025306A1

Abstract

The invention mainly relates to a method for compensating the aperiodic behaviour of a motor vehicle heat engine (12), the heat engine (12) belonging to a drive train (10), characterized in that it comprises: -a step of measuring a physical parameter related to the rotation of the crankshaft of the heat engine (12); -performing the step of measuring a physical parameter by means of a sensor (27, 27') located between the mechanical damper (20) and the heat engine (12); -a step of determining from the measured physical parameter the torque variation associated with the aperiodic behaviour of the heat engine (12) taking into account the transfer function induced by the mechanical damper (20); -a step of subtracting the torque variation from a reference torque setpoint (Cref) of the rotating electrical machine (17) to determine a control torque setpoint (Cref'); -a step (106) of operating the rotating electrical machine (17) to obtain a control torque setpoint (Cref').

Description

Method and system for compensating irregularities of a heat engine by means of a rotating electrical machine

Technical Field

The invention relates to a method and a system for compensating irregularities of a heat engine by means of a rotating electrical machine.

Background

The traction chain of a motor vehicle comprises, in a known manner, a heat engine coupled to a gearbox by means of a clutch. The gear box is mechanically connected with the wheels through differential gears. Typically, the crankshaft of the heat engine is connected to a mechanical damper and then to a clutch to transfer energy to the wheels through a gearbox.

In addition, a rotating electrical machine may be implanted in the traction chain to improve the energy balance of the vehicle. The electric machine may be operated in a motor mode to ensure traction of the vehicle, either alone or in combination with the heat engine, to provide assistance in traction. The electric machine may also be operated in a generator mode to provide energy to a battery of the vehicle and/or to a charge coupled to the power grid.

In operation, the torque of the heat engine fluctuates due to the detonation and compression of fuel within the cylinders. These fluctuations in torque result in significant changes in speed, which are damped by the inertia present on the heat engine shaft. However, despite the presence of the damper placed on the crankshaft of the heat engine, the variations are still large, causing vibrations and design constraints of the mechanical parts.

Disclosure of Invention

The object of the present invention is to eliminate this drawback at least partially by exploiting the presence of a rotating electric machine located downstream of the mechanical damper.

To this end, the subject of the invention is a method for compensating for irregularities of a heat engine of a motor vehicle, wherein the heat engine belongs to a traction chain comprising:

-a mechanical damper;

-a rotating electrical machine;

-a gearbox comprising at least one clutch,

characterized in that the method comprises:

-a step of measuring a physical parameter related to the rotation of the output shaft of the heat engine;

-performing the step of measuring a physical parameter by means of a sensor arranged between the mechanical damper and the heat engine;

-a step of determining the torque variation associated with the irregularities of the heat engine from the measured physical parameter, taking into account the transfer function caused by the mechanical damper;

-a step of subtracting the torque variation from a reference torque setpoint of the rotating electrical machine to determine a control torque setpoint;

-a step of controlling the rotating electric machine to obtain a control torque setpoint.

The invention thus makes it possible to reduce the torque variations of the heat engine thanks to a rotating electrical machine that, in addition to its conventional motor and generator functions, performs the function of compensating for irregularities by drawing or supplying current from or to the battery of the vehicle. The invention thus makes it possible to greatly reduce irregularities of the heat engine.

The step of controlling the rotating electrical machine to obtain a control torque setpoint makes it possible to compensate for at least part of the residual irregularities generated by the mechanical damper and entering the gearbox through the clutch.

According to an embodiment, the step of determining the torque variation associated with the irregularity takes into account a transfer function caused only by the mechanical damper.

According to an embodiment, the step of determining the torque variation associated with the irregularity comprises the step of applying a filter to the measurement signal of the physical parameter, the filter being representative of the irregularity of the heat engine damped by the mechanical damper.

According to one embodiment, a filter representing the irregularities of the damping of the heat engine by the mechanical damper is determined from the entire kinematic chain.

According to an embodiment, the filter representing the damping irregularity takes into account the inertial load applied to the mechanical damper, such as the weight of the rotating machine and the damper.

According to an embodiment, the method comprises, before the step of applying a filter representing the damping, a step of eliminating successive components of the measurement signal of the physical parameter.

According to an embodiment, the method comprises the step of inverting the measurement signal of the physical parameter, successive components of the measurement signal of the physical parameter having been eliminated.

According to an embodiment, the physical parameter measured is torque.

According to an embodiment, the physical parameter measured is the rotational speed. In this case, the method further includes a phase correction step to convert the rotational speed into torque.

According to an embodiment, the rotating electrical machine is arranged between a clutch and a mechanical damper of the gearbox.

According to an embodiment, the rotary electric machine is arranged between two clutches to allow an electric drive mode and a thermal drive mode of the motor vehicle.

The invention also relates to a system for compensating for irregularities of a heat engine of a motor vehicle, wherein the heat engine belongs to a traction chain comprising:

-a mechanical damper;

-a rotating electrical machine;

-a gearbox comprising at least one clutch,

characterized in that the system comprises:

-a sensor for measuring a physical parameter related to the rotation of the crankshaft of the heat engine, wherein the measuring sensor is arranged between the mechanical damper and the heat engine;

-means for determining from the measured physical parameter a torque variation related to irregularities of the heat engine;

-means for subtracting the torque variation from a reference torque setpoint of the rotating electrical machine to determine a control torque setpoint;

-means for controlling the rotating electric machine to obtain a control torque setpoint.

The invention will be better understood by reading the following description and by referring to the accompanying drawings. These drawings are provided by way of illustration only and in no way limit the invention.

Drawings

Fig. 1a and 1b are schematic diagrams showing two embodiments of a traction chain for a motor vehicle with which the method for compensating for irregularities of a heat engine according to the invention is implemented;

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

FIG. 2b is a diagram of the steps of a method according to the invention implemented with the system for compensating for irregularities in FIG. 2 a;

FIG. 3a is a schematic view of a second embodiment of a system for compensating for irregularities in a heat engine according to the present invention;

fig. 3b is a diagram of the steps of a method according to the invention implemented with the system for compensating irregularities in fig. 3 a.

The same, similar or analogous elements remain the same reference numbers in the various figures.

Detailed Description

Fig. 1a and 1b show a traction chain 10 implanted on an assembly 11 of a motor vehicle.

The traction chain 10 comprises a heat engine 12 and a gearbox 13, the gearbox 13 being provided with an input shaft 13.1 and an output shaft 13.2 connected to the wheels via a differential gear 16. The clutch K1 is interposed between the heat engine 12 and the input shaft 13.1 of the gearbox 13.

A rotary electric machine 17 of the reversible type is provided between the clutch K1 and the heat engine 12. More specifically, the electric machine 17 is disposed between the clutch K1 and the mechanical damper 20 fitted on the crankshaft of the heat engine 12.

The electric machine 17 can operate in generator mode during a regenerative braking phase supplying current on the network, for example to charge a battery (not shown) and/or to supply current to a load, and in motor mode to assist the heat engine 12 and, where applicable, to open the clutch K0 to ensure electric drive of the vehicle, as shown in fig. 1 b.

Advantageously, as shown in fig. 2a and 3a, the mechanical damper 20, the electric motor 17 and the clutch K1 are housed in a single casing 21.

The optional rotating electrical machine 24 may be coupled to the heat engine 12 by a face on an accessory facade (facade) belt. The means 25 for transmitting motion between the heat engine 12 and the electric machine 24 may comprise, for example, a belt cooperating with pulleys supported by the crankshaft and by the shaft of the electric machine 24, respectively. The electric machine 24, which is commonly known as an alternator-starter, may be operated in a generator mode to charge the vehicle's battery, and in a motor mode to ensure that the heat engine 12 is started when the vehicle is stopped or during a transition from an electric drive mode to a thermal drive mode.

The motor 17 preferably has an operating voltage of 48V. As a variant, the motor 17 may have an operating voltage comprised in the range 48V and 350V. The motor 24 has an operating voltage of 12V, 24V or 48V. The

electric machines

17, 24 may each be of the synchronous type with permanent magnets and synchronous with a wound rotor, for example. An asynchronous motor may be used.

In the embodiment of fig. 1b, a second clutch K0 is used. The motor 17 is fitted between the first clutch K1 and the second clutch K0. Thus, in the electric operating mode, the clutch K0 is open and K1 is closed. In the hot operating mode, both clutches K0 and K1 are closed.

With reference to fig. 2a and 2b, a description of a first embodiment of a system and method for compensating for irregularities of a heat engine 12 according to the present invention is provided below.

In step 100, a torque meter type sensor 27 disposed between the mechanical damper 20 and the heat engine 12 ensures that the torque of the crankshaft of the heat engine 12 is measured. The torque measurement signal obtained has a reference S _ C.

Then, in step 101, the torque variation associated with the irregularity of the heat engine 12 is determined from the measured torque.

To this end, in step 102, the continuous component of the torque signal S _ C is eliminated by the module 29.

In step 103, the output signal S _ C' of the module 29 for eliminating the continuous component is inverted and comprises a gain that can be unified by the module 30.

Then, in step 104, the filter 33 is applied to the signal obtained from the inverter module 30. This filter 33 represents the damping of the kinematic chain, i.e. the damping of irregularities of the heat engine 12 by the mechanical damper 20. This filter 33 takes into account, among other things, the inertial loads imposed on the damper, such as the weight of the motor 17 and the damper 20.

In step 105, this torque variation is combined with the reference torque setpoint Cref of the rotary electric machine 17 by means of the adder 34 to determine a control torque setpoint Cref', which integrates the torque variation to be applied to compensate for the irregularities of the heat engine 12. The use of adder 34 is specified here because signal S _ C' has been previously inverted by module 30. As a variant, in a strictly equivalent way, it is possible to eliminate the inverter module 30 and to subtract the torque variation associated with the irregularity from the reference torque Cref using the comparator module.

The rotating electrical machine 17 is then controlled in step 106 to obtain a control torque setpoint Cref'.

For this purpose, a control torque setpoint Cref' is applied in the chain 36 for the conventional torque control of the electric machine 17. The chain 36 comprises a comparator 37 to compare the input control torque signal Cref' with the output signal of a model 38 of the rotating electric machine 17. This model 38 is associated with a power module 39 with a rectifier bridge of transistors, also having an inverter function, to inject a current into the phase windings of the stator 17.1 in order to obtain the desired control torque setpoint Cref' on the shaft on which the rotor 17.2 of the electric machine 17 is assembled. The output signal of the comparator 37 is advantageously corrected by a corrector 42, for example of the PI (proportional-integral) or P (proportional) type.

With reference to fig. 3a and 3b, a description of a first embodiment of a system and method for compensating for irregularities of a heat engine 12 according to the present invention is provided below. The obtained speed measurement signal has a reference S _ V.

In step 100, a speed sensor 27' disposed between the mechanical damper 20 and the heat engine 12 ensures that the rotational speed of the crankshaft of the heat engine 12 is measured.

Then, in step 101, the torque variation associated with the irregularity of the heat engine 12 is determined from the measured rotational speed.

To this end, in step 102, the continuous component of the speed signal S _ V is eliminated by the module 29.

In step 103, the output signal S _ V' of the module 29 for eliminating the continuous component is inverted by the module 30.

Then, in step 104, the filter 33 is applied to the signal obtained from the inverter module 30. This filter 33 represents the damping of irregularities of the heat engine 12 by the mechanical damper 20. This filter 33 takes into account in particular the inertial loads applied to the damper, for example by the weight of the motor 17 and the damper 20.

In step 105, the signal obtained from the filter 33 is phase corrected via the module 41 in order to convert the rotation speed into a torque variation associated with an irregularity. In this case, the applied phase shift is 90 °.

In step 106, this torque variation is combined by the adder 34 with the reference torque setpoint Cref 'of the rotating electrical machine 17 to determine a control torque setpoint Cref', which incorporates the variable torque to be applied to compensate for irregularities of the heat engine 12. The use of adder 34 is specified here because signal S _ C' has been previously inverted by module 30. As a variant, in a strictly equivalent way, it is possible to eliminate the inverter module 30 and to subtract the torque variation associated with the irregularity from the reference torque Cref using the comparator module.

The rotating electrical machine 17 is then controlled in step 107 to obtain a control torque setpoint Cref'.

For this purpose, a control torque setpoint Cref' is applied in a conventional torque control chain 36 of the electric machine 17. The chain 36 comprises a comparator 37 to compare the input control torque signal Cref' with the output signal of a model 38 of the rotating electric machine 17. This model 38 relates to a power module 39 with a rectifier bridge of transistors, also having an inverter function, to inject a current into the phase windings of the stator 17.1 to obtain the desired control torque setpoint Cref' on the shaft on which the rotor 17.2 of the electric machine 17 is fitted. The output signal of the comparator 37 is advantageously corrected by a corrector 42, for example of the PI (proportional-integral) or P (proportional) type.

It is to be understood that the above description has been provided by way of example only and is not limiting on the field of the invention, and that no deviation from the invention will be constituted by the replacement of different elements by any other equivalent.

In addition, different features, variations and/or embodiments of the present invention may be associated with each other according to various combinations, as long as they are not incompatible or mutually exclusive.

Claims

1. Method for compensating for irregularities of a heat engine (12) of a motor vehicle, wherein the heat engine (12) belongs to a traction chain (10), the traction chain (10) comprising:

-a mechanical damper (20);

-a rotating electrical machine (17);

-a gearbox (13) comprising at least one clutch (K1);

characterized in that the method comprises:

-a step (100) of measuring a physical parameter related to the rotation of the output shaft of the heat engine (12);

-performing the step of measuring a physical parameter by means of a sensor (27, 27') arranged between the mechanical damper (20) and the heat engine (12);

-a step (101) of determining from the measured physical parameter the torque variation related to the irregularities of the heat engine (12) taking into account the transfer function induced by the mechanical damper (20);

-a step (105) of subtracting the torque variation from a reference torque setpoint (Cref) of the rotating electrical machine (17) to determine a control torque setpoint (Cref');

-a step (106) of controlling the rotating electrical machine (17) to obtain a control torque setpoint (Cref').

2. A method according to claim 1, characterized in that the step (101) of determining the torque variation associated with said irregularity comprises the step (104) of applying a filter (33) to the measurement signal of the physical parameter, the filter (33) being representative of the irregularity of the heat engine (12) damped by the mechanical damper (20).

3. Method according to claim 2, characterized in that the filter (33) representing the damping of said irregularities takes into account the inertial load applied to the mechanical damper (20).

4. A method according to claim 2 or 3, characterized in that it comprises, before the step of applying a filter (33) representative of the damping, a step (102) of eliminating the continuous component of the measurement signal of the physical parameter.

5. A method according to claim 4, characterized in that the method comprises a step (103) of inverting the measurement signal of the physical parameter, successive components of the measurement signal of the physical parameter having been eliminated.

6. A method according to any of claims 1-5, characterized in that the measured physical parameter is torque.

7. A method according to any of claims 1 to 5, characterized in that the physical parameter measured is the rotational speed.

8. A method according to claim 7, characterized in that the method comprises a phase correction step (105) to convert the rotational speed into torque.

9. Method according to any of claims 1-8, characterized in that the rotating electrical machine (17) is arranged between the clutch (K1) of the gearbox (13) and the mechanical damper (20).

10. Method according to any one of claims 1 to 8, characterized in that the rotating electrical machine (17) is arranged between two clutches (K0, K1) to allow an electric drive mode and a thermal drive mode of the motor vehicle.

11. A system for compensating irregularities of a heat engine (12) of a motor vehicle, wherein the heat engine (12) belongs to a traction chain (10), the traction chain (10) comprising:

-a mechanical damper (20);

-a rotating electrical machine (17);

-a gearbox (13) comprising at least one clutch (K1),

characterized in that the system comprises:

-a sensor (27, 27') for measuring a physical parameter related to the rotation of the crankshaft of the heat engine (12), wherein said measuring sensor (27, 27') is arranged between the mechanical damper (20) and the heat engine (12);

-means (29, 30, 33) for determining from the measured physical parameter a torque variation related to irregularities of the heat engine (12);

-means (37) for subtracting the torque variation from a reference torque setpoint (Cref) of the rotating electrical machine (17) to determine a control torque setpoint (Cref);

-means (36, 37, 38, 39, 42) for controlling the rotating electrical machine (17) to obtain a control torque setpoint (Cref').