Control system for a motor vehicle and method

Patent metadata

Field	Value
Publication number	US-10843570-B2
Application number	US-201615770599-A
Country	US
Kind code	B2
Filing date	Dec 9, 2016
Priority date	Dec 9, 2015
Publication date	Nov 24, 2020
Grant date	Nov 24, 2020

Abstract

A motor vehicle control system ( 210 C, 220 ) for controlling an electric propulsion motor ( 230 ) to drive a wheel ( 290 ) of the vehicle ( 200 ), the control system ( 210 C, 220 ) being configured to operate in one of a first mode and a second mode in dependence at least in part on an amount of slip experienced by at least one driven wheel ( 290 ), in the first mode the control system ( 210 C, 220 ) being configured to cause the at least one electric propulsion motor ( 230 ) to generate a predetermined amount of drive torque, in the second mode the control system ( 210 C, 220 ) being configured to cause the at least one electric propulsion motor ( 230 ) to rotate at a predetermined speed, wherein the control system ( 210 C, 220 ) is configured to operate in the first mode if the amount of slip experienced by the at least one driven wheel ( 290 ) is below a predetermined slip amount and to operate in the second mode if the amount of slip experienced by the at least one driven wheel ( 290 ) exceeds the predetermined slip amount.

First claim

The invention claimed is:

1. A motor vehicle control system for controlling at least one electric propulsion motor to drive a wheel of the vehicle, the control system configured to operate in one of a first mode and a second mode in dependence at least in part on an amount of slip experienced by at least one driven wheel,
wherein, in the first mode, the control system is configured to cause the at least one electric propulsion motor to generate a predetermined amount of drive torque,
wherein, in the second mode, the control system is configured to cause the at least one electric propulsion motor to rotate at a predetermined speed by controlling commutation of the motor so as to enforce a desired speed on rotation of a magnetic field of the motor, and
wherein the control system is configured to operate in the first mode if the amount of slip experienced by the at least one driven wheel is below a predetermined slip amount and to operate in the second mode if the amount of slip experienced by the at least one driven wheel exceeds the predetermined slip amount.

2. The control system according to claim 1 , wherein the at least one electric propulsion motor is a synchronous motor.

3. The control system according to claim 2 , wherein the at least one electric propulsion motor is a switched reluctance motor or a permanent magnet DC electric motor.

4. The control system according to claim 1 , wherein control of the at least one electric propulsion motor in the first mode is performed in dependence on an estimate of an angular position of a rotor of the at least one electric propulsion motor.

5. The control system according to claim 1 , wherein the control system is further configured to calculate the amount of slip experienced by the at least one driven wheel in dependence on a reference speed signal indicative of a speed of travel of the vehicle over ground and at least one driven wheel speed signal.

6. The control system according to claim 1 , wherein the control system is further configured to receive information indicative of a surface coefficient of friction between the at least one driven wheel and a driving surface, and wherein the control system is further configured to set the predetermined slip amount in dependence on the information indicative of the surface coefficient of friction.

7. The control system according to claim 6 , wherein the control system is further configured to receive information indicative of a driving mode in which the vehicle is being operated.

8. The control system according to claim 7 , wherein the control system is further configured to receive information indicative of a state of a user-operable driving mode control input for selecting a driving mode of the vehicle.

9. The control system according to claim 7 , wherein the driving mode is one of a plurality of control modes of at least one subsystem of the vehicle.

10. The control system according to claim 9 , wherein the control system is further configured to initiate control of the at least one subsystem of the vehicle in a selected one of the plurality of subsystem control modes, each of the subsystem control modes corresponding to one or more different driving surfaces.

11. The control system according to claim 1 , wherein the predetermined slip amount is calculated in dependence on whether the control system is causing a positive torque to be applied to the at least one driven wheel or a negative torque to be applied to the at least one driven wheel.

12. The control system according to claim 1 , wherein the predetermined slip amount is set to a first value if the control system is causing a positive torque to be applied to the at least one driven wheel and a second value if the control system is causing a negative torque to be applied to the at least one driven wheel.

13. The control system according to claim 1 , wherein the control system is further configured to control a plurality of electric propulsion motors each configured to drive a respective wheel of the vehicle.

14. The control system according to claim 1 , wherein the control system is further configured to determine that the amount of slip experienced by the at least one driven wheel exceeds the predetermined slip amount if a speed of the at least one driven wheel exceeds a speed indicated by a speed control signal.

15. A vehicle, comprising:
a plurality of wheels;
a powertrain to drive the plurality of wheels;
a braking system to brake the plurality of wheels; and
a control system, configured to operate in one of a first mode and a second mode in dependence at least in part on an amount of slip experienced by at least one of the wheels,
wherein, in the first mode, the control system is configured to cause the powertrain to generate a predetermined amount of drive torque,
wherein, in the second mode, the control system is configured to cause the powertrain to rotate at a predetermined speed by controlling commutation of a motor of the powertrain so as to enforce a desired speed on rotation of a magnetic field of the motor, and
wherein the control system is configured to operate in the first mode if the amount of slip experienced by at least one of the wheels is below a predetermined slip amount and to operate in the second mode if the amount of slip experienced by at least one of the wheels exceeds the predetermined slip amount.

16. A method of controlling an electric propulsion motor to drive at least one wheel of a vehicle, the method comprising:
causing a control system to operate in one of a first mode and a second mode in dependence at least in part on an amount of slip experienced by the at least one wheel,
whereby in the first mode the method comprises causing the electric propulsion motor to generate a predetermined amount of drive torque, and
in the second mode the method comprises causing the electric propulsion motor to rotate at a predetermined speed by controlling commutation of the electric propulsion motor so as to enforce a desired speed on a rotation of a magnetic field of the electric propulsion motor,
whereby the control system is configured to operate in the first mode if an amount of wheel slip is below a predetermined slip amount and to operate in the second mode if an amount of wheel slip exceeds the predetermined slip amount.

17. A non-transitory computer readable carrier medium carrying computer readable code that, when executed by one or more processors, causes the one or more processors to control a vehicle to carry out the method of claim 16 .

Assignees

• Jaguar Land Rover Ltd

Inventors

• Greenwood Jeremy
• Barber Phil

Classifications

• B60L2220/46

  Wheel motors, i.e. motor connected to only one wheel · CPC title

• B60L3/108

  whilst braking, i.e. ABS · CPC title

• B60L15/20 Primary

  for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed · CPC title

• B60L2240/465

  Slip · CPC title

• Y02T10/64

  Electric machine technologies in electromobility · CPC title