Car control method and car control apparatus

• US 7,423,393 B2
• Filed: 05/06/2003
• Issued: 09/09/2008
• Est. Priority Date: 05/07/2002
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Bridgestone
• Original Assignee: Kabushiki Kaisha Bridgestone
• Inventors: Wakao, Yasumichi, Akutagawa, Keizo
• Primary Examiner(s): Leykin; Rita
• Application Number:
  US10/512,429
• Publication Number:
  US 20050274560A1
• Time in Patent Office: 1,953 Days
• Field of Search: 318650-652, 318371-375, 318432-434
• US Class Current: 318/371
• CPC Class Codes: B60L 15/20 for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 2220/46 Wheel motors, i.e. motor connected to only one wheel
• CPC Class Codes: B60L 3/102 of individual wheels
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

A car control apparatus including a wheel sensor, wheel torque calculating means for calculating wheel torque from the wheel speed, drive force detecting means for detecting drive force generated by an electric motor, car body drive force calculating means for calculating car body drive force from the above drive force and wheel torque, car body drive force fluctuating component extracting means for extracting multiple frequency band fluctuating components of the car body drive force, and drive or braking force control unit for controlling the running state of a car.

Claims

1. A car control method comprising the steps of:

detecting drive force and wheel torque to be applied to each drive wheel;

calculating car body drive force by subtracting the wheel torque from the drive force;

extracting at least one frequency band fluctuating component of the calculated car body drive force; and

driving or braking the wheel or providing vibration to the wheel based on the extracted fluctuating component of the car body drive force to control the running state of the car.

2. The car control method according to claim 1, wherein multiple frequency band fluctuating components of the calculated car body drive force are extracted to control drive or braking force to be applied to the drive wheel based on the extracted fluctuating components of car body drive force.

3. The car control method according to claim 1 or 2, wherein drive force to be applied to the output shaft of the drive wheel is detected, and fluctuating components including at least a frequency band of 10 Hz to 1 kHz are extracted from car body drive force calculated from the drive force and wheel torque.

4. The car control method according to claim 1 or 2, wherein drive or braking force generated by a motor for driving or braking the drive wheel is detected, and fluctuating components including at least a frequency band of 10 Hz to 10 kHz are extracted from car body drive force calculated from the drive or braking force and wheel torque.

5. The car control method according to claim 3, wherein a 10 Hz to 200 Hz fluctuating component out of the fluctuating components of the car body drive force is extracted to suppress a change in the car body drive force.

6. The car control method according to claim 5, wherein a 30 to 100 Hz fluctuating component out of the fluctuating components of the car body drive force is extracted to suppress a change in the car body drive force.

7. The car control method according to claim 1, wherein left and right drive wheels are controlled independently.

8. The car control method according to claim 7, wherein the left and right drive wheels are controlled independently based on a change in steering properties.

9. The car control method according to claim 1, wherein the running state of the car is controlled based on a vertical load applied to each tire.

26. The car control method according to claim 4, wherein a 10 Hz to 200 Hz fluctuating component out of the fluctuating components of the car body drive force is extracted to suppress a change in the car body drive force.

10. A car control apparatus comprising:

means of detecting the wheel speed of each drive wheel;

means of calculating wheel torque from the detected wheel speed;

means of detecting drive force applied to the drive wheel;

means of calculating car body drive force by subtracting the wheel torque from the drive force;

means of extracting at least one frequency band fluctuating component from the calculated car body drive force; and

running state control means for controlling the running state of a car based on the extracted fluctuating component of the car body drive force.

11. The car control apparatus according to claim 10, wherein drive or braking force generated by a motor for driving or braking the drive wheel is detected to detect drive or braking force applied to the drive wheel.

12. The car control apparatus according to claim 10 or 11, wherein the running state control means has means of driving or braking the wheel based on the extracted fluctuating component of the car body drive force.

13. The car control apparatus according to claim 12, wherein means of calculating the speed difference between the car body speed and the wheel speed by extracting a 0.2 Hz to 100 Hz frequency band fluctuating component of the car body drive force is provided to drive or brake the wheel based on the calculated speed difference.

14. The car control apparatus according to claim 10, wherein left and right drive wheels are controlled independently.

15. The car control apparatus according to claim 14, wherein means of extracting 10 Hz or lower frequency band fluctuating components of the car body drive forces of the left and right drive wheels are provided to control the left and right drive wheels independently based on the respective extracted fluctuating components.

16. The car control apparatus according to claim 15 which comprises means of detecting the steering angle of a steering system, means of detecting the yaw rate of the car body, means of detecting a change in steering properties from the detected steering angle and yaw rate and judging the instability of the car body and which drives or brakes one or both of a drive wheel on the inner side of turning and a drive wheel on the outer side of turning according to the change in steering properties when it is judged that the car body is unstable.

17. The car control apparatus according to claim 10, wherein the running state control means has means of applying vibration to the tire based on the extracted fluctuating component of the car body drive force.

18. The car control apparatus according to claim 17, wherein means of calculating disturbance applied to the tire by extracting a 10 Hz to 10 kHz frequency band fluctuating component of the car body drive force is provided to apply vibration to the tire based on the calculated disturbance.

19. The car control apparatus according to claim 18, wherein a 10 Hz to 200 Hz frequency band fluctuating component out of the fluctuating components of the car body drive force is extracted to suppress a change in the car body drive force.

20. The car control apparatus according to claim 19, wherein a 30 Hz to 100 Hz frequency band fluctuating component out of the fluctuating components of the car body drive force is extracted to suppress a change in the car body drive force.

21. The car control apparatus according to claim 10, wherein means of detecting a vertical load applied to the tire is provided to control the running state of the car based on the detected vertical load.

22. The car control apparatus according to claim 21 which further comprises means of detecting the displacement of a suspension, means of detecting the normal acceleration of the wheel and means of calculating the vertical load from the detected displacement of the suspension and the normal acceleration of the wheel.

23. The car control apparatus according to claim 14, wherein the motor is an in-wheel motor for driving the wheel with an electric motor attached to the wheel.

24. The car control apparatus according to claim 23, wherein the motor is a gearless direct drive in-wheel motor.

25. The car control apparatus according to claim 24, wherein the motor is attached to one or both of a portion below the car spring and the car body through a buffer member or buffer device.

27. The car control apparatus according to claim 11, wherein left and right drive wheels are controlled independently.

28. The car control apparatus according to claim 12, wherein left and right drive wheels are controlled independently.

29. The car control apparatus according to claim 13, wherein left and right drive wheels are controlled independently.