Control device for an electric motor of a traction chain, associated method and vehicle

Abstract

A control device for an electric motor of a powertrain (4) of an electric or hybrid motor vehicle is proposed. The device comprises: - first determination means (11) configured to determine a correction torque (Tcorr), - second determination means (14) configured to determine a corrected control torque setpoint (Tcons-corr) of the electric motor from a control torque setpoint (Tcons) of the electric motor and the correction torque (Tcorr), and - control means (15) configured to control the electric motor from the corrected control torque setpoint (Tcons-corr). The first determination means (11) are configured to determine the correction torque (Tcorr) from an estimation of the rotational speed (ωm) of the electric motor to attenuate or eliminate oscillations of a torque delivered by the powertrain (4) to move the vehicle (1).Figure for abstract: Fig 3.

Description

Title of the invention: Control device for an electric motor of a traction chain, associated method and vehicle

[0001] The present invention relates to the control of electric motors for the propulsion of electric or hybrid vehicles.

[0002] The present invention relates more particularly to a method for controlling an electric motor of a powertrain of an electric or hybrid vehicle, a control device for such an electric motor, and an electric or hybrid motor vehicle comprising such a device.

[0003] An electric or hybrid motor vehicle comprises a powertrain generally comprising an electric motor, a reducer, a transmission shaft and wheels connected to the ends of the transmission shaft.

[0004] The electric motor drives the drive shaft via the reducer to drive the vehicle wheels and move the vehicle.

[0005] The electric motor is controlled according to a torque instruction delivered for example by a vehicle pedal.

[0006] The electric motor transmits a mechanical torque to the wheels via the reducer and the transmission shaft, the value of the delivered torque being determined from the torque setpoint.

[0007] However, the electric motor, the reducer, the transmission shaft and the wheels have inertial, stiffness, damping and non-linearity components.

[0008] These components determine the dynamic behavior of the drive train and disrupt the application of engine torque to the wheels.

[0009] When an acceleration or deceleration torque instruction is transmitted to the electric motor, the requested torque is not transmitted immediately to the wheels.

[0010] The drive train behaves like an oscillating system so that the torque delivered to the wheels oscillates strongly when the torque delivered by the electric motor varies and gradually diminishes to disappear.

[0011] The oscillations of the torque delivered to the wheels are felt by the occupants of the vehicle and cause inconvenience.

[0012] It is known to reduce oscillations by correcting the torque setpoint from a measurement of the engine rotation speed (or the vehicle speed). More precisely, it is proposed to derive the engine rotation speed twice to extract only the annoying oscillations, to multiply the engine rotation speed derived twice by a coefficient and finally to subtract the result from a setpoint of torque. This solution is suitable for oscillations occurring in vehicles with internal combustion engines. This solution is not fast enough to deal with oscillations within an electric or hybrid vehicle. Also, this solution has the disadvantage of being late compared to oscillations that it cannot anticipate.

[0013] Reference may also be made to document WO 2012 / 011521 which proposes using a direct corrector and a feedback corrector. The direct corrector in this document filters variations in the torque setpoint in order to avoid over-exciting the frequencies in the resonance zone of the powertrain. The feedback corrector reduces oscillations by modifying the gain and phase of the frequency response of the powertrain in the resonance zone.

[0014] Document FR3000854 proposes injecting the torque setpoint as requested by the driver at the input of the feedback corrector, the corrector comprising a pure delay so that the torque setpoint as requested by the driver is applied at the input of the corrector and not an setpoint obtained after the feedback loop.

[0015] These methods compensate for oscillations in the torque delivered by the drive train.

[0016] The known methods reduce the oscillations when the oscillations are detected so that the methods are not effective when the oscillations occur and for a time necessary for the torque correction loops to establish.

[0017] Furthermore, the implementation of the known methods requires knowing the rotation speed of the electric motor with high precision and a high response time to obtain effective oscillation correction.

[0018] The aim of the invention is to overcome all or part of these drawbacks.

[0019] The subject of the invention is a method for controlling an electric motor of a powertrain of an electric or hybrid motor vehicle.

[0020] The method comprises:

[0021] - a determination of a correction torque,

[0022] - a determination of a corrected control torque setpoint of the motor electric from an electric motor control torque setpoint and correction torque, and

[0023] - a control of the electric motor from the control torque setpoint corrected.

[0024] The correction torque is determined from an estimate of the rotational speed of the electric motor to attenuate or eliminate oscillations of a torque delivered by the drive train to move the vehicle.

[0025] Advantageously, the drive train comprises drive wheels of the motor vehicle, the electric motor driving the drive wheels of the motor vehicle, the estimation of the rotation speed of the electric motor includes:

[0026] - a determination of the rotational speed of the wheels of the motor vehicle, and

[0027] - determining the estimate of the rotation speed of the electric motor at from a model of the powertrain having input parameters including the rotation speed of the wheels of the motor vehicle and the corrected control torque setpoint controlling the electric motor.

[0028] Preferably, the determination of the correction torque comprises:

[0029] - a determination of the rotation speed of the electric motor,

[0030] - a determination of the difference between the estimate of the rotation speed of the electric motor and the rotation speed of the electric motor,

[0031] - a determination of a driving state of the vehicle among an acceleration state or a state of deceleration of the motor vehicle from the control torque setpoint of the electric motor,

[0032] - a determination of a correction value equal to the multiplication of the difference by a gain, the value of the gain being chosen according to the driving condition of the vehicle, and

[0033] - a limit of the correction value between a predetermined lower limit and a predetermined upper bound, the bounded correction value being equal to the correction torque.

[0034] Advantageously, the rotation speed of the electric motor is determined from the rotation speed of the wheels of the motor vehicle.

[0035] A control device is also proposed for an electric motor of a powertrain of an electric or hybrid motor vehicle.

[0036] The device comprises:

[0037] - first determination means configured to determine a pair of correction,

[0038] - second determination means configured to determine a setpoint corrected control torque of the electric motor from a control torque setpoint of the electric motor and the correction torque, and

[0039] - control means configured to control the electric motor from of the corrected control torque instruction.

[0040] The first determination means are configured to determine the correction torque from an estimation of the rotational speed of the electric motor to attenuate or eliminate oscillations of a torque delivered by the drive train to move the vehicle.

[0041] Preferably, the powertrain comprises drive wheels of the motor vehicle, the electric motor being configured to drive the drive wheels of the motor vehicle, the first determining means comprise means for estimating the rotation speed of the electric motor, the estimation means being configured to:

[0042] - implement a model of the powertrain having input parameters comprising the rotation speed of the wheels of the motor vehicle and the corrected control torque setpoint controlling the electric motor, and

[0043] - determine the estimate of the rotation speed of the electric motor from the implementation of the powertrain model.

[0044] Advantageously, the powertrain further comprises a gearbox and a transmission shaft, the drive wheels being arranged at the ends of the transmission shaft, the engine being configured to drive the transmission shaft via the gearbox, and

[0045] the model of the traction chain includes:

[0046] - a first inertia modeling the electric motor,

[0047] - a second inertia modeling the drive wheels,

[0048] - a game,

[0049] - a transformation ratio modeling the gearbox, and

[0050] - a stiffness coefficient and a damping coefficient modeling the shaft of transmission.

[0051] Preferably, the first determination means comprise means for developing the correction torque configured to:

[0052] - determine the difference between the estimate of the engine rotation speed electric and the rotation speed of the electric motor,

[0053] - determining a driving state of the vehicle from among an acceleration state or a state of deceleration of the motor vehicle from the electric motor control torque setpoint,

[0054] - determine a correction value equal to the multiplication of the difference by a gain, the value of the gain being chosen according to the driving condition of the vehicle, and

[0055] - limit the correction value between a predetermined lower limit and a limit predetermined upper limit, the bounded correction value being equal to the correction torque.

[0056] Advantageously, the device further comprises third determination means configured to determine the rotation speed of the electric motor from the rotation speed of the wheels of the motor vehicle.

[0057] An electric or hybrid motor vehicle is also proposed comprising a powertrain comprising an electric motor, and a control device as defined previously and connected to the electric motor.

[0058] Other aims, characteristics and advantages of the invention will appear on reading the following description, given solely by way of non-limiting example, and made in reference to the attached drawings in which:

[0059] [Fig.l]

[0060] schematically illustrates an example of a motor vehicle according to the invention;

[0061] [Fig.2]

[0062] schematically illustrates an example of a traction chain according to the invention;

[0063] [Fig.3]

[0064] schematically illustrates an example of a closed control loop implemented by a control device according to the invention;

[0065] [Fig.4]

[0066] schematically illustrates an example of a model of the traction chain according to the invention, and

[0067] [Fig.5]

[0068] schematically illustrates one embodiment of development means according to the invention.

[0069] [Fig.l] schematically illustrates an example of an electric or hybrid motor vehicle 1.

[0070] The vehicle 1 comprises drive wheels 2 driven by a traction chain 4 to move the vehicle 1.

[0071] The drive train 4 comprises an electric motor 5.

[0072] The vehicle 1 further comprises a control device 6, a human-machine interface 7 and a battery 8.

[0073] The human-machine interface 7 comprises, for example, a pedal operated by the driver of the vehicle 1 to deliver a torque instruction Tcons.

[0074] The battery 8 is connected to the control device 6 to power the electric motor 5.

[0075] The control device 6 is capable of controlling the electric motor 5 so that the electric motor 5 powered by the battery 8 delivers a mechanical torque Tm to drive the drive wheels 2, the mechanical torque being determined from the setpoint torque Tcons.

[0076] The drive wheels 2 driven by the electric motor 5 are capable of delivering a mechanical torque Tl to move the vehicle 1.

[0077] [Fig.2] schematically illustrates an example of the traction chain 4.

[0078] The drive train 4 comprises the drive wheels 2, the electric motor 5, a gearbox 9 having a transmission ratio i and a transmission shaft 10 connected to the gearbox 9.

[0079] The driving wheels 2 are arranged at the ends of the transmission shaft 10.

[0080] A rotor shaft of the electric motor 5 is connected to an input shaft of the gearbox speed 9 so that the mechanical torque Tm delivered by the electric motor 5 multiplied by the transmission ratio i is transmitted to the drive wheels 2 by through the drive shaft 10.

[0081] The control device 6 comprises first determination means 11 capable of determining a correction torque Tcorr to attenuate vibrations generated by the traction chain 4.

[0082] The first determination means 11 comprise means 12 for estimating the rotation speed of the electric motor 5 and means 13 for developing the correction torque Tcorr.

[0083] The control device 6 further comprises second determination means 14 capable of determining a corrected control torque setpoint Tcons-corr of the electric motor 5 from the torque setpoint Tcons and the correction torque Tcorr.

[0084] The control device 6 comprises control means 15 capable of controlling the electric motor 5 from the corrected control torque setpoint Tcons-corr and third determination means 16 capable of determining the rotation speed of the electric motor 5 from the rotation speed of the wheels of the motor vehicle 1, for example from the rotation speed of the drive wheels 2.

[0085] The control means 15 comprise, for example, a computer.

[0086] [Fig. 3] illustrates an example of a closed control loop 17 implemented by the control device 6.

[0087] The regulation loop 17 comprises the first determination means 11 comprising the estimation means 12 of the rotation speed of the electric motor 5, the means 13 of developing the correction torque Tcorr, the second determination means 14, the third determination means 16, and a system 18 comprising the control means 15 and the traction chain 4.

[0088] The second determination means 14 comprise, for example, a comparator 19 comprising a first input 19a receiving the torque setpoint Tcons, a second input 19b receiving the correction torque Tcorr and an output 19c delivering the corrected control torque setpoint Tcons-corr equal to the difference between the torque setpoint Tcons and the corrected control torque setpoint Tcons-corr, the corrected control torque setpoint Tcons-corr being delivered to the control means 15 of the system 18.

[0089] The estimation means 12 comprise a first input 12a connected to the output 19c of the comparator 19 delivering the corrected control torque setpoint, a second input 12b receiving the rotation speed of the wheels of the vehicle 1 delivered at the output of the system 18. The speed of the wheels is for example measured by a speed sensor.

[0090] The estimation means 12 further comprise an output 12c delivering an es- Timing of the rotation speed of the electric motor 5.

[0091] The estimation means 12 implement a model MODEL of the drive train 4 having input parameters comprising the rotation speed of the wheels of the vehicle 1 delivered on the second input 12b and the corrected control torque setpoint Tcons-corr delivered on the first input 12a to determine an estimate of the rotation speed of the electric motor 5.

[0092] The estimation means 12 comprise for example a processing unit 20 capable of implementing the model MODEL detailed below.

[0093] The processing means 13 comprise a first input 13a connected to the output 12c of the estimation means 12, a second input 13b, a third input 13c receiving information representative of an acceleration or deceleration instruction of the vehicle determined for example from the actuation of the pedal, and an output 13d connected to the second input 19b of the comparator 19, the output 13d delivering the correction torque Tcorr.

[0094] The information representative of an acceleration or deceleration instruction is for example a square wave signal, the rising edge of the signal and the high logic state of the square wave being representative of the acceleration instruction, and the falling edge of the signal and the low logic state of the square wave being representative of the deceleration instruction.

[0095] The processing means 13 comprise, for example, a corrector 21 capable of determining the correction torque Tcorr from the speed estimate provided by the estimation means 12, the measured rotation speed of the electric motor 5 delivered to the second input 13b and the information delivered to the third input 13c.

[0096] The processing means 13 are capable of determining a driving state of the vehicle 1 from among an acceleration state or a deceleration state of the motor vehicle 1.

[0097] The third determination means 16 comprise an input 16a receiving the rotation speed of the wheels of the vehicle 1 delivered at the output of the system 18 and an output 16b connected to the second input 13b of the processing means 13.

[0098] The third determining means 16 determine and deliver to the output 16b the measured rotational speed of the engine 5 by multiplying the rotational speed of the wheels of the vehicle 1 by the transmission ratio i of the gearbox 9.

[0099] The first determination means 11 determine the correction torque Tcorr from an estimate of the rotation speed of the electric motor 5.

[0100] The estimation of the rotation speed of the electric motor 5 is determined by the estimation means 12 of the first determination means 11.

[0101] [Fig.4] schematically illustrates an example of the MODEL model of the traction chain 4.

[0102] The MODEL model includes a first inertia Jm modeling the engine electric 5, the transformation ratio i modeling the gearbox 9, a stiffness coefficient k in Nmrad 1 and a damping coefficient c in Nmrad '.s modeling the transmission shaft 10, a clearance J modeling the clearance in the traction chain 4 generating a delay in the transmission of the torque from the electric machine 5 to the drive wheels 2, and a second inertia Jw modeling the drive wheels 2.

[0103] We note:

[0104] Tm the mechanical torque generated by the electric machine 5 on the input shaft of the gearbox 9,

[0105] Ti: the torque transmitted by the drive wheels 2,

[0106] 0m: the rotation angle of the rotor of the electric motor 5,

[0107] com: the rotation speed of the rotor of the electric motor 5,

[0108] 0W: the rotation angle of the wheels 2 of the vehicle 1,

[0109] cow: the rotation speed of the wheels 2 of the vehicle 1,

[0110] a: the maximum value of the play angle J in the traction chain 4,

[0111] 0b: the angle of the game J varying between - a and +a.

[0112] The MODEL model is governed by the following equations.

[0113] When 0b is equal to a or - a: [°! 14 1 J = T„ - 4 »„ - 4 u>„ +1 + f œ,„ + H < 1 )

[0115] 1 ¢.+fw„, -ke„- cum -kO^T^)

[0116] When 0b is equal to a:

[0117] f)h = min^ K0m + - a\v - ~ 9b) 0)

[0118] When 0b is equal to - a:

[0119] éb = maX(O,~j0m + ]wm-~0w- <vw-^eb) (4)

[0120] When 0b is between a and - a:

[0121] Jmœm = Tm (5)

[0122] = -Ti (6) [°123] Ôb = ^m +} œm- -œw4 3h (7)

[0124] In the preceding equations, X is the time derivative operator.

[0125] The inertias J and J are known.

[0126] The stiffness coefficient k and the damping coefficient c modeling the transmission shaft 10, and the play angle in the traction chain 4 are for example determined from tests carried out on the traction chain 4.

[0127] [Fig.5] schematically illustrates an example of embodiment of the development means 13.

[0128] The development means 13 comprise two comparators 25, 26, a filter 27, a multiplier 28, three selection devices 29, 30, 31, a first device of rising edge detection 32, a second falling edge detection device 33, two timers 34, 35 and two limiting devices 36, 37.

[0129] Each selection device 29, 30, 31 comprises a control input 29a, 30a, 31a, a first input 29b, 30b, 31b, a second input 29c, 30c, 31c and an output 29d, 30d, 31d. Depending on the value received on the control input 29a, 30a, 31a, the output 29d, 30d, 31d is connected to the first input 29b, 30b, 31b or to the second input 29c, 30c, 31c.

[0130] A first input 25a of a first comparator 25 is connected to the first input 13a of the processing means 13 and a second input 25b of the first comparator 25 is connected to the second input 13b of the processing means 13.

[0131] The first comparator 25 comprises an output 25c delivering the difference between the values ​​received on the first and second inputs 25a, 25b.

[0132] The filter 27 comprises an input 27a connected to the output 25c of the first comparator 25 and an output 27b connected to a first input 28a of the multiplier 28.

[0133] Filter 27 is for example a high-pass filter or a phase advance filter. It corrects the dynamics of the signal received at its input 27a.

[0134] As a variant, the processing means 13 do not include the filter 27, the output 25c of the first comparator 25 being connected directly to the first input 28a of the multiplier 28.

[0135] The control input 29a of a first selection device 29 is connected to the third input 13c of the processing means 13, the first input 29b of said device is connected to a first gain, for example equal to -1, and the second input 29c of said device is connected to a first gain, for example equal to 1.

[0136] The output 29d of the first selection device 29 is connected to a second input 28b of the multiplier 28.

[0137] An output 28c of the multiplier 28 is connected to the first input 30b of a second selection device 30 and the first input 31b of the third selection device 31.

[0138] The multiplier 28 delivers on its output 28c the product of the signal received on its first input 28a by the signal received on its second input 28b.

[0139] The second input 30c, 31c of the second and third selection devices 30, 31 is connected to a gain, for example zero.

[0140] An input 32a of the first detection device 32 is connected to the third input 13c of the processing means 13 and an output 32b of said device is connected to the control input 30a of the second selection device 30 via a first time delay 34.

[0141] An input 33a of the second detection device 33 is connected to the third input 13c of the processing means 13 and an output 33b of said device is connected to the input of command 31a of the third selection 31 via the second time delay 35.

[0142] The output 30d of the second selection device 30 is connected to an input 36a of a first limiting device 36.

[0143] An output 36b of the first limiting device 36 is connected to a first input 26a of the second comparator 26.

[0144] The output 31d of the third selection device 31 is connected to an input 37a of the second limiting device 37.

[0145] An output 37b of the second limiting device 37 is connected to a second input 26b of the second comparator 26.

[0146] Each limiting device 36, 37 delivers on its output 36b, 37b a limited value between a predetermined lower limit and a predetermined upper limit.

[0147] An output 26c of the second comparator 26 is connected to the output 13d of the processing means 13, said output delivering the difference between the signal received on the first input 26a and the signal received on the second input 26b.

[0148] Now, an example of a method for controlling the electric motor 5 implementing the control device 6 is described.

[0149] Upon receiving the torque setpoint Tcons, the second determination means 14 determine the corrected control torque setpoint Tcons-corr. The control means 15 control the electric motor 5 according to the corrected control torque setpoint Tcons-corr.

[0150] Furthermore, the first determination means 11 determine the correction torque Tcorr.

[0151] The estimation means 12 estimate the rotation speed of the electric motor 5.

[0152] The estimation means 12 implement the model MODEL having pa input meters including the wheel rotation speed and the corrected control torque setpoint Tcons-corr controlling the electric motor 5.

[0153] The estimation means 12 inject into the input of the MODEL model the corrected control torque setpoint Tcons-corr so that the mechanical torque Tm generated by the electric machine 5 is equal to the corrected control torque setpoint Tcons-corr and inject into the input of the MODEL model the rotation speed of the wheels measured for example by a speed sensor so that the rotation speed cow of the wheels of the MODEL model is equal to the measured wheel speed, then the estimation means 12 determine the rotation speed com of the electric motor 5 from the equations (1) to (7) of the MODEL model.

[0154] The rotation speed com determined from the model MODEL is the estimate of the rotation speed of the electric motor 5.

[0155] The first comparator 25 of the processing means 13 determines the difference between the estimation of the rotation speed of the electric motor 5 determined by the estimation means 12 and the rotation speed of the electric motor 5 determined by the third determination means 16. The difference determined by the first comparator 25 is filtered by the filter 27 and the filtered difference is delivered to the first input 28a of the multiplier 28.

[0156] Depending on the logical state of the information received on the third input 13c of the processing means 13, the first selection device 29 delivers on its output 29d the first gain (first input 29b) or the second gain (second input 29c).

[0157] If a rising edge is detected on the third input 13c of the processing means 13, the first detection device 32 triggers the first time delay 34 so that for a first predetermined duration starting from the detection of a rising edge, the first time delay 34 delivers a first control signal on the control input 30a of the second selection device 30.

[0158] As long as the first control signal is applied to the control input 30a of the second selection device 30, the signal received on the first input 30b of the second selection device 30 is transmitted to the input 35a of the first limiting device 36. The received signal is limited then transmitted to the first input 26a of the second comparator 26. If the first control signal is not applied to the control input 30a of the second selection device 30, the zero signal received on the second input 30c of the second selection device 30 is transmitted to the input 36a of the first limiting device 36 then to the first input 26a of the second comparator 26.

[0159] If a falling edge is detected on the third input 13c of the processing means 13, the second detection device 33 triggers the second time delay 35 so that for a second predetermined duration starting from the detection of a falling edge, the second time delay 35 delivers a second control signal on the control input 31a of the third selection device 31.

[0160] As long as the second control signal is applied to the control input 31a of the third selection device 31, the signal received on the first input 31b of the third selection device 31 is transmitted to the input 37a of the second limiting device 37. The received signal is limited then transmitted to the second input 26b of the second comparator 26. If the second control signal is not applied to the control input 31a of the third selection device 31, the zero signal received on the second input 31c of the third selection device 31 is transmitted to the input 36a of the second limiting device 37 then to the second input 26b of the second comparator 26.

[0161] The first predetermined duration is for example between 0.1 second and 1 second.

[0162] The second predetermined duration is for example between 0.1 second and 1 second.

[0163] The information representing acceleration or deceleration is the torque setpoint Tcons.

[0164] If the derivative of the torque setpoint Tcons is positive (vehicle acceleration state 1), the first selection device 29 delivers the first gain to the second input 28b of the multiplier 28 and the first detection device 32 detects a rising edge and triggers the first time delay 34. The second selection device 30 receives the first control signal of the first time delay 34 and delivers on its output 30d a correction value equal to the product of the first gain and the filtered difference delivered to the output 28c of the filter 28. The correction value is limited and then delivered to the output 26c of the second comparator 26, the correction value being equal to the correction torque Tcorr.

[0165] If the derivative of the torque setpoint Tcons is negative or zero (deceleration state of vehicle 1), the first selection device 29 delivers the second gain to the second input 28b of the multiplier 28 and the second detection device 33 detects a falling edge and triggers the second time delay 35.

[0166] The third selection device 31 receives the second control signal from the second time delay 35 and delivers on its output 31d a correction value equal to the product of the second gain and the filtered difference delivered on the output 28c of the filter 28. The correction value is limited then delivered on the output 26c of the second comparator 26, the correction value being equal to the correction torque Tcorr.

[0167] The processing means 13 determine the driving state of the vehicle 1 from among the acceleration state or the deceleration state of the vehicle 1 from the torque setpoint Tcons for controlling the electric motor 5 and determine the correction value equal to the multiplication of the difference by a gain, the value of the gain being chosen according to the driving state of the vehicle. If the vehicle accelerates, the value of said gain is equal to the first gain and if the vehicle decelerates, the value of said gain is equal to the second gain.

[0168] The second determining means 14 determine and update the corrected control torque setpoint Tcons-corr from the control torque setpoint Tcons and the correction torque Tcorr delivered by the output 26c of the second comparator 26 and the control means 15 control the electric motor 5 from the corrected control torque setpoint Tcons-corr. The comparator 19 of the second determining means 14 determine and deliver on the output 19c the corrected control torque setpoint Tcons-corr equal to the difference between the control torque setpoint Tcons delivered on the first input 19a and the correction torque Tcorr delivered on the second input 19b.

[0169] The correction torque Tcorr is determined from an estimate of the rotation speed of the electric motor 5 and makes it possible to attenuate or eliminate oscillations of the torque delivered by the drive train 4 to move the vehicle, the torque being the torque delivered by the drive wheels 2.

[0170] The method for controlling the electric motor 5 implements an estimation of the rotation speed of the electric motor 5 so that the control method does not require knowing the rotation speed of the electric motor making it possible to correct the torque setpoint controlling the electric motor 5 before the appearance of oscillations so that the oscillations generated are attenuated or eliminated unlike the methods known from the state of the art which seek to compensate for the oscillations of the torque when said oscillations are detected.

[0171] The method for controlling the electric motor 5 is effective as soon as a torque setpoint Tcons is generated, unlike the methods known from the state of the art which are effective after an initialization time necessary for the torque correction loops to be established, the initialization time starting when the oscillations appear.

[0172] The method for controlling the electric motor 5 preventatively corrects the oscillations.

Claims

Claims

1. Method for controlling an electric motor (5) of a powertrain (4) of an electric or hybrid motor vehicle (1), the method comprising: - a determination of a correction torque (Tcorr), - a determination of a control torque setpoint corrected (Tcons-corr) of the electric motor (5) from a torque setpoint (Tcons) for controlling the electric motor (5) and the correction torque, and - a control of the electric motor (5) from the corrected control torque setpoint, characterized in that - the correction torque (Tcorr) is determined from an estimate of the rotation speed (œm) of the electric motor (5) to attenuate or eliminate oscillations of a torque (Tl) delivered by the drive train (4) to move the vehicle (1).

2. Method according to claim 1, in which the powertrain (4) comprises drive wheels (2) of the motor vehicle, the electric motor (5) driving the drive wheels of the motor vehicle (1), the estimation of the rotational speed of the electric motor comprising: - a determination of the rotation speed (œw) of the wheels (2) of the motor vehicle, and - determining the estimate of the rotation speed (œm) of the electric motor (5) from a model of the drive train (4) having input parameters comprising the rotation speed (œw) of the wheels (2) of the motor vehicle and the corrected control torque setpoint (Tcons-corr) controlling the electric motor.

3. Method according to claim 1 or 2, wherein the determination of the correction torque (Tcorr) comprises: electric (5), - a determination of the difference between the estimate of the rotational speed of the electric motor and the rotational speed (œm) of the electric motor (5), - a determination of a driving state of the vehicle among an acceleration state or a deceleration state of the motor vehicle (5) from the torque setpoint (Tcons) for controlling the electric motor, - a determination of a correction value equal to the multiplication of the difference by a gain, the value of the gain being chosen according to the driving state of the vehicle, and - a limitation of the correction value between a predetermined lower limit and a predetermined upper limit, the limited correction value being equal to the correction torque.

4. Method according to claim 3, wherein the rotational speed (œm) of the electric motor (5) is determined from the rotational speed (œw) of wheels (2) of the motor vehicle.

5. Control device (6) for an electric motor (5) of a powertrain (4) of an electric or hybrid motor vehicle (1), the device comprising: - first determination means (11) configured to determine a correction torque (Tcorr), - second determination means (14) configured to determine a corrected control torque setpoint (Tcons-corr) of the electric motor (5) from a control torque setpoint (Tcons) of the electric motor and the correction torque (Tcorr), and - control means (15) configured to control the electric motor (5) from the corrected control torque setpoint (Tcons-corr), characterized in that the first determination means (11) are configured to determine the correction torque (Tcorr) from an estimation of the rotation speed (œm) of the electric motor (5) for attenuate or eliminate oscillations of a torque (Tl) delivered by the drive train (4) to move the vehicle (1).

6. Device according to claim 5, wherein the powertrain (4) comprises drive wheels (2) of the motor vehicle (1), the electric motor (5) being configured to drive the drive wheels of the motor vehicle, the first determination means (11) comprising means (12) for estimating the rotational speed (œm) of the electric motor (5), the estimation means being configured to: - implement a model (MODEL) of the powertrain (4) having input parameters comprising the rotational speed (œw) of the wheels (2) of the motor vehicle and the corrected control torque setpoint (Tcons-corr) controlling the electric motor (5), and - determine the estimation of the rotational speed (œm) of the electric motor (5) from the implementation of the model of the powertrain (4).

7. Device according to claim 6, wherein the powertrain (4) further comprises a gearbox (9) and a transmission shaft (10), the drive wheels (2) being arranged at the ends of the transmission shaft, the motor (5) being configured to drive the transmission shaft via the gearbox, and the model of the powertrain comprising: - a first inertia (Jm) modeling the electric motor (5), - a second inertia (Jw) modeling the drive wheels (2), - a clearance (J), - a transformation ratio (i) modeling the gearbox (9), and - a stiffness coefficient (k) and a damping coefficient (c) modeling the transmission shaft (10).

8. Device according to any one of claims 5 to 7, in which the first determination means (11) comprise means (13) for developing the correction torque (Tcorr) configured to: rotation (œm) of the electric motor (5) and the rotation speed (œm) of the electric motor, - determining a driving state of the vehicle (1) from among an acceleration state or a deceleration state of the motor vehicle from the torque setpoint (Tcons) for controlling the electric motor, - determining a correction value equal to the multiplication of the difference by a gain, the value of the gain being chosen according to the driving state of the vehicle, and - limiting the correction value between a predetermined lower limit and a predetermined upper limit, the limited correction value being equal to the correction torque (Tcorr).

9. Device according to claim 8, further comprising third determination means (16) configured to determine the rotation speed (œm) of the electric motor (5) from the rotation speed of wheels (2) of the motor vehicle (1).

10. Electric or hybrid motor vehicle (1), comprising a powertrain (4) comprising an electric motor (5), and a control device (6) according to any one of claims 5 to 9 connected to the electric motor.

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