Driving control device and methods for vehicle

• US 6,539,298 B2
• Filed: 02/25/2002
• Issued: 03/25/2003
• Est. Priority Date: 02/28/2001
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Hattori, Yoshikazu, Inagaki, Shoji
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): Marc-Coleman, Marthe Y.
• Application Number:
  US10/080,667
• Publication Number:
  US 20020147532A1
• Time in Patent Office: 393 Days
• Field of Search: 701/70, 701/83, 701/84, 701/82, 701/41, 701/87, 701/53, 477/34, 477/115, 477/107
• US Class Current: 701/70
• CPC Class Codes: B60G 17/0195 characterised by the regulation being combined with other vehicle control systems conjoint control of vehicle sub-units including control of suspension systems B60W10/22
• CPC Class Codes: B60G 2400/104 lateral or transversal with regard to vehicle
• CPC Class Codes: B60G 2400/106 longitudinal with regard to vehicle, e.g. braking
• CPC Class Codes: B60G 2400/34 Accelerator pedal position
• CPC Class Codes: B60G 2400/38 Speed of engine rotation
• CPC Class Codes: B60G 2400/39 Brake pedal position
• CPC Class Codes: B60G 2400/41 Steering angle
• CPC Class Codes: B60G 2800/18 Starting, accelerating
• CPC Class Codes: B60G 2800/22 Braking, stopping
• CPC Class Codes: B60G 2800/24 Steering, cornering
• CPC Class Codes: B60G 2800/96 ASC - Assisted or power Steering control
• CPC Class Codes: B60G 2800/97 Engine Management System [EMS]
• CPC Class Codes: B60T 2260/02 Active Steering, Steer-by-Wire
• CPC Class Codes: B60T 8/17552 responsive to the tire sideslip angle or the vehicle body slip angle
• CPC Class Codes: B60W 2710/18 Braking system
• CPC Class Codes: B60W 2710/20 Steering systems
• CPC Class Codes: B60W 2720/14 Yaw
• CPC Class Codes: B62D 6/002 computing target steering angles for front or rear wheels B62D7/159 takes precedence
• CPC Class Codes: B62D 7/159 characterised by computing methods or stabilisation processes or systems, e.g. responding to yaw rate, lateral wind, load, road condition

Abstract

A driving control device and methods including controllers for independently controlling a steering angle, and braking and driving force of each wheel. The device includes detectors that detect driver input including a steering operation amount, a driving force operation amount, and a braking force operation amount. Moreover, the device includes calculators that calculate a vehicle target longitudinal and lateral force, and a vehicle target yaw moment based on the inputs by the driver, a target generating force of each wheel based on the detected amounts, and a target steering angle and target braking and driving torque of each wheel based on the target generating force of each wheel. Finally, a controller controls the device so that a steering angle and the braking and driving torque of each wheel are determined to be the target steering angle and the target braking and driving torque.

Claims

1. A driving control device for a vehicle comprising:

a first controller that controls a steering angle of each wheel;

a second controller that controls a braking and driving force of each wheel;

a first detector that detects a steering operation amount by a driver of the vehicle;

a second detector that detects a driving operation amount by the driver;

a third detector that detects a braking operation amount by the driver;

a first calculator that calculates a vehicle target longitudinal force, a vehicle target lateral force, and a vehicle target yaw moment based on the detected steering operation amount, the detected driving force operation amount, and the detected braking force operation amount;

a second calculator that calculates a target generating force of each wheel based on the target longitudinal force, the target lateral force, and the target yaw moment;

a third calculator that calculates a target steering angle and target braking and driving torque based on the target generating force of each wheel; and

a third controller that controls the first and second controllers so that a steering angle and the braking and driving torque of each wheel are determined to be the target steering angle and the target braking and driving torque respectively.

2. The driving control device according to claim 1, wherein the second calculator determines a direction and a strength of the vehicle target generating force of each wheel so that a direction of a resultant force of the target generating force of each wheel matches a direction of a resultant force of the vehicle target lateral force and the vehicle target longitudinal force, and so that the vehicle target longitudinal force, the vehicle target lateral force, and the vehicle target yaw moment are achieved by the resultant force of the target generating force of each wheel.

3. The driving control device according to claim 2, wherein the second calculator further comprises a fourth calculator that calculates a first target generating force of each wheel for achieving the vehicle target lateral force and a vehicle target longitudinal force without giving the target yaw moment to a vehicle, and a fifth calculator that calculates a second target generating force of each wheel for achieving only the target yaw moment and calculates the target generating force of each wheel as a total of the first target generating force and the second target generating force.

4. The driving control device according to claim 3, wherein the vehicle comprises right and left front wheels and right and left rear wheels, the second calculator further comprises a fourth controller that obtains a vertical load of each wheel, the fourth calculator calculates the first target generating force of each wheel by distributing the resultant force of the vehicle target longitudinal force and the vehicle target lateral force to each wheel proportional to the vertical load of each wheel, and the fifth calculator further comprises a fifth controller that calculates a yaw moment generating force of front wheels as a total of a force which is to be generated by the right and left front wheels for achieving only the target yaw moment based on a direction of the resultant force of the vehicle target lateral force and the vehicle target longitudinal force and the target yaw moment, and for calculating a yaw moment generating force of the rear wheels which has a predetermined relationship relative to the yaw moment generating force of the front wheels as a total of a force which is to be generated by the right and left rear wheels, and a sixth controller that calculates the second target generating force of each wheel by distributing the yaw moment generating force of the front wheel to the right and left front wheels being proportional to the vertical load of right and left front wheels, and by distributing the yaw moment generating force of the rear wheel to the right and left rear wheels proportional to the vertical load of right and left rear wheels.

5. The driving control device according to claim 4, wherein the yaw moment generating force of the front wheel and the yaw moment generating force of the rear wheel are the same value.

6. The driving control device according to claim 4, wherein a distance between a center of a gravity of the vehicle and a front wheel axle in a vehicle longitudinal direction is determined to be Lf, and a distance between the center of the gravity of the vehicle and a rear wheel axle in vehicle longitudinal direction is determined to be Lr, wherein a ratio of the yaw moment generating force of the front wheels relative to the yaw moment generating force of the rear wheels corresponds to Lr/Lf.

7. The driving control device according to claim 4, wherein the fourth controller that obtains the vertical load of each wheel calculates the vertical load of each wheel based on a mass of the vehicle, a vehicle longitudinal acceleration, and a vehicle lateral acceleration.

8. The driving control device according to claim 3, wherein the second calculator further comprises a sixth calculator that obtains the vertical load of each wheel, the second calculator calculates the first target generating force of each wheel by distributing the resultant force of the vehicle target longitudinal force and the vehicle target lateral force being proportional to the vertical load of each wheel, the third calculator specifies a wheel which is appropriate for effectively generating the second target generating force based on the vehicle target longitudinal force and the vehicle target lateral force, and a seventh calculator that calculates the second target generating force as a force which is vertical to the first target generating force regarding the specified wheel, the second calculator further determines the target generating force of the specified wheel to the resultant force of the first target generating force and the second target generating force, determines the target generating force of the wheel which is not specified to the corresponding first target generating force, and corrects the strength of the target generating force of the wheel which is not specified and the target generating force of the specified wheel so that the resultant force of the target generating force of the specified wheel and the target generating force of the wheel which is not specified achieves the vehicle target lateral force and the vehicle target longitudinal force.

9. The driving control device according to claim 8, wherein the third calculator specifies one of the right and left wheels which has a longer arm length of the yaw moment around the center of the gravity of the vehicle by the second target generating force as a wheel appropriate for effectively generating the second target generating force.

10. The driving control device according to claim 8, wherein the vehicle is a four-wheel vehicle having right and left-front wheels and right and left-rear wheels, and the third calculator specifies two wheels, front-left wheel and rear-right wheel or front-right wheel and rear-left wheel, based on a direction of the vehicle target longitudinal force and the vehicle target lateral force when the target longitudinal force of the vehicle and the vehicle target lateral force are not zero.

11. The driving control device according to claim 10, wherein the fifth calculator that calculates the second target generating force corrects the strength of the second target generating force to be the first target generating force of the wheel when the calculated second target generating force is greater than the first target generating force of the specified wheel.

12. The driving control device according to claim 8, wherein the vehicle is a four-wheel vehicle having right and left-front wheels and right and left-rear wheels, and the third calculator specifies all wheels when either one or both of the vehicle target longitudinal force and the vehicle target lateral force are zero.

13. The driving control device according to claim 12, wherein the fifth calculator that calculates the second target generating force corrects the strength of the second target generating force to be the strength of the first target generating force when the strength of the calculated second target generating force is greater than the first target generating force of the specified wheel.

14. The driving control device according to claim 1, wherein the third calculator comprises a seventh calculator that calculates a target traveling direction angle of a grounding point of each wheel relative to the vehicle longitudinal direction, an eighth calculator that calculates a target vertical load of each wheel, a ninth calculator that calculates a target wheel longitudinal force and a target wheel lateral force at a wheel coordinates of each wheel based on the target generating force and a previous target angle, a tenth calculator that calculates a target slip angle of each wheel as a total of the previous target steering angle and the target traveling direction angle at grounding point of each wheel, an eleventh calculator that calculates a target slip ratio and a lateral force predicted value of each wheel based on the target wheel longitudinal force of each wheel, the target slip angle of each wheel, and the target vertical load of each wheel, and a twelfth calculator that calculates a target steering angle and a target rotation torque of each wheel based on the target wheel longitudinal force of each wheel, the target wheel lateral force of each wheel, the lateral force predicted value of each wheel, and the target slip ratio of each wheel.

15. The driving control device according to claim 14, wherein the twelfth calculator that calculates the target steering angle and the target rotation torque of each wheel determines the target steering angle of each wheel to be the previous target steering angle when a deviation between the target wheel lateral force and the lateral force predicted value is less than a predetermined value, and calculates a target steering angle correction amount based on the deviation between the target wheel lateral force and the lateral force predicted value, and determines the target steering angle of each wheel to be a value that the previous target steering value is corrected with the target steering angle correction amount when the deviation between the target wheel lateral force and the lateral force predicted value is greater than the predetermined value.

16. The driving control device according to claim 15, wherein the twelfth calculator that calculates the target steering angle and the target rotation torque of each wheel calculates a target steering angle correction amount as a value proportional to the deviation between the target wheel lateral force and the lateral force predicted value.

17. The driving control device according to claim 14, wherein the vehicle comprises a power source and a drivetrain for transmitting a driving torque of the power source to each wheel with a predetermined distribution ratio, the second controller comprises a seventh controller that controls the driving force of all wheels by controlling the driving torque of the power source, and an eighth controller which is capable of independently controlling the braking force of each wheel, and the third calculator calculates the target driving torque of the power source based on a maximum value on driving side in the target rotation torque of each wheel and calculates the target braking force control amount based on the target rotation torque of other wheels and the maximum value regarding the other wheels other than the wheel having the maximum target rotation torque.

18. The driving control device according to claim 14, wherein the twelfth calculator that calculates the target steering angle and the target rotation torque of the wheel calculates a correction amount of the target steering angle of each wheel based on the target wheel lateral force and the lateral force predicted value of each wheel, and calculates the target steering angle of each wheel as a total of the previous target steering angle and the correction amount of the target steering angle.

19. The driving control device according to claim 14, wherein the twelfth calculator that calculates the target steering angle and the target rotation torque of each wheel calculates the target wheel acceleration of each wheel based on the target slip ratio of each wheel, and calculates a target rotation torque of each wheel as a total of a second target rotation torque based on the target wheel acceleration of each wheel and a first rotation torque based on the target wheel longitudinal force of each wheel.

20. The driving control device according to claim 1, wherein the first calculator calculates a vehicle target longitudinal acceleration, a vehicle target lateral acceleration, and a vehicle target yaw rate based on the steering operation amount, the driving force operation amount, and the braking force operation amount by the driver and calculates the vehicle target longitudinal force, the vehicle target lateral force, and the vehicle target yaw moment based on the vehicle target longitudinal acceleration, the vehicle target lateral acceleration, and the vehicle target yaw rate respectively.

21. The driving control device according to claim 1, wherein the second controller comprises a seventh controller and an eighth controller.

22. The driving control device according to claim 21, wherein the seventh controller controls the driving force of all wheels, and the eighth controller is capable of independently controlling the braking force of each wheel.

23. The driving control device according to claim 21, wherein the seventh controller is capable of independently controlling the driving force of each wheel, and the eighth controller is capable of independently controlling the braking force of each wheel.

24. The driving control device according to claim 1, wherein the vehicle corresponds to a four-wheel vehicle having right and left-front wheels and right and left-rear wheels.

25. A driving control method for a vehicle comprising:

detecting a steering operation amount by a driver of the vehicle;

detecting a driving operation amount by the driver;

detecting a braking operation amount by the driver, calculating a vehicle target longitudinal force, a vehicle target lateral force, and a vehicle target yaw moment based on the detected steering operation amount, the detected driving force operation amount, and the detected braking force operation amount;

calculating a target generating force of each wheel based on the target longitudinal force, the target lateral force, and the target yaw moment;

calculating a target steering angle and target braking and driving torque based on the target generating force of each wheel; and

controlling a steering angle and the braking and driving torque of each wheel of the vehicle to be the target steering angle and the target braking and driving torque respectively.

26. The driving control method according to claim 25, further comprising:

determining a direction and a strength of the vehicle target generating force of each wheel so that a direction of a resultant force of the target generating force of each wheel matches a direction of a resultant force of the vehicle target lateral force and the vehicle target longitudinal force, and so that the vehicle target longitudinal force, the vehicle target lateral force, and the vehicle target yaw moment are achieved by the resultant force of the target generating force of each wheel.

27. The driving control method according to claim 26, further comprising:

calculating a first target generating force of each wheel for achieving the vehicle target lateral force and a vehicle target longitudinal force without giving the target yaw moment to a vehicle;

calculating a second target generating force of each wheel for achieving only the target yaw moment; and

calculating the target generating force of each wheel as a total of the first target generating force and the second target generating force.

28. The driving control method according to claim 27, wherein the vehicle comprises right and left front wheels and right and left rear wheels, further comprising:

obtaining a vertical load of each wheel;

calculating the first target generating force of each wheel by distributing the resultant force of the vehicle target longitudinal force and the vehicle target lateral force to each wheel proportional to the vertical load of each wheel;

calculating a yaw moment generating force of front wheels as a total of a force which is to be generated by the right and left front wheels for achieving only the target yaw moment based on a direction of the resultant force of the vehicle target lateral force and the vehicle target longitudinal force and the target yaw moment;

calculating a yaw moment generating force of the rear wheels which has a predetermined relationship relative to the yaw moment generating force of the front wheels as a total of a force which is to be generated by the right and left rear wheels;

calculating the second target generating force of each wheel by distributing the yaw moment generating force of the front wheel to the right and left front wheels being proportional to the vertical load of right and left front wheels; and

distributing the yaw moment generating force of the rear wheel to the right, left rear wheels proportional to the vertical load of right and left rear wheels.

29. The driving control method according to claim 28, wherein the yaw moment generating force of the front wheel and the yaw moment generating force of the rear wheel are the same value.

30. The driving control method according to claim 28, wherein a distance between a center of a gravity of the vehicle and a front wheel axle in a vehicle longitudinal direction is determined to be Lf, a distance between the center of the gravity of the vehicle and a rear wheel axle in vehicle longitudinal direction is determined to be Lr, and a ratio of the yaw moment generating force of the front wheels relative to the yaw moment generating force of the rear wheels corresponds to Lr/Lf.

31. The driving control device according to claim 28, further comprising obtaining the vertical load of each wheel by calculating the vertical load of each wheel based on a mass of the vehicle, a vehicle longitudinal acceleration, and a vehicle lateral acceleration.

32. The driving control method according to claim 27, further comprising:

obtaining the vertical load of each wheel;

calculating the first target generating force of each wheel by distributing the resultant force of the vehicle target longitudinal force and the vehicle target lateral force being proportional to the vertical load of each wheel;

specifying a wheel which is appropriate for effectively generating the second target generating force based on the vehicle target longitudinal force and the vehicle target lateral force;

calculating the second target generating force as a force which is vertical to the first target generating force regarding the specified wheel;

determining the target generating force of the specified wheel to the resultant force of the first target generating force and the second target generating force;

determining the target generating force of the wheel which is not specified to the corresponding first target generating force; and

correcting the strength of the target generating force of the wheel which is not specified and the target generating force of the specified wheel so that the resultant force of the target generating force of the specified wheel and the target generating force of the wheel which is not specified achieves the vehicle target lateral force and the vehicle target longitudinal force.

33. The driving control method according to claim 32, further comprising specifying one of the right and left wheels which has a longer arm length of the yaw moment around the center of the gravity of the vehicle by the second target generating force as a wheel appropriate for effectively generating the second target generating force.

34. The driving control method according to claim 32, wherein the vehicle corresponds to a four-wheel vehicle having right and left-front wheels and right and left-rear wheels, further comprising specifying two wheels, front-left wheel and rear-right wheel or front-right wheel and rear-left wheel, based on a direction of the vehicle target longitudinal force and the vehicle target lateral force when the target longitudinal force of the vehicle and the vehicle target lateral force are not zero.

35. The driving control method according to claim 34, further comprising correcting the strength of the second target generating force to be the first target generating force of the wheel when the calculated second target generating force is greater than the first target generating force of the specified wheel.

36. The driving control method according to claim 32, wherein the vehicle corresponds to a four-wheel vehicle having right and left-front wheels and right and left-rear wheels, further comprising specifying all wheels when either one or both of the vehicle target longitudinal force and the vehicle target lateral force are zero.

37. The driving control method according to claim 36, further comprising correcting the strength of the second target generating force to be the strength of the first target generating force when the strength of the calculated second target generating force is greater than the first target generating force of the specified wheel.

38. The driving control method according to claim 25, further comprising:

calculating a target traveling direction angle of a grounding point of each wheel relative to the vehicle longitudinal direction;

calculating a target vertical load of each wheel;

calculating a target wheel longitudinal force and a target wheel lateral force at a wheel coordinates of each wheel based on the target generating force and a previous target angle;

calculating a target slip angle of each wheel as a total of the previous target steering angle and the target traveling direction angle at grounding point of each wheel;

calculating a target slip ratio and a lateral force predicted value of each wheel based on the target wheel longitudinal force of each wheel, the target slip angle of each wheel, and the target vertical load of each wheel; and

calculating a target steering angle and a target rotation torque of each wheel based on the target wheel longitudinal force of each wheel, the target wheel lateral force of each wheel, the lateral force predicted value of each wheel, and the target slip ratio of each wheel.

39. The driving control method according to claim 38, further comprising:

determining the target steering angle of each wheel to be the previous target steering angle when a deviation between the target wheel lateral force and the lateral force predicted value is less than a predetermined value;

calculating a target steering angle correction amount based on the deviation between the target wheel lateral force and the lateral force predicted value; and

determining the target steering angle of each wheel to be a value that the previous target steering value is corrected with the target steering angle correction amount when the deviation between the target wheel lateral force and the lateral force predicted value is greater than the predetermined value.

40. The driving control method according to claim 39, further comprising calculating a target steering angle correction amount as a value proportional to the deviation between the target wheel lateral force and the lateral force predicted value.

41. The driving control method according to claim 38, further comprising:

transmitting a driving torque of the power source to each wheel with a predetermined distribution ratio;

controlling the driving force of all wheels by controlling the driving torque of the power source;

controlling independently the braking force of each wheel;

calculating the target driving torque of the power source based on a maximum value on driving side in the target rotation torque of each wheel; and

calculating the target braking force control amount based on the target rotation torque of other wheels and the maximum value regarding the other wheels other than the wheel having the maximum target rotation torque.

42. The driving control method according to claim 38, further comprising calculating a correction amount of the target steering angle of each wheel based on the target wheel lateral force and the lateral force predicted value of each wheel, and calculating the target steering angle of each wheel as a total of the previous target steering angle and the correction amount of the target steering angle.

43. The driving control method according to claim 38, further comprising calculating the target wheel acceleration of each wheel based on the target slip ratio of each wheel, and calculating a target rotation torque of each wheel as a total of a second target rotation torque based on the target wheel acceleration of each wheel and a first rotation torque based on the target wheel longitudinal force of each wheel.

44. The driving control method according to claim 25, further comprising calculating a vehicle target longitudinal acceleration, a vehicle target lateral acceleration, and a vehicle target yaw rate based on the steering operation amount, the driving force operation amount, and the braking force operation amount by the driver and calculating the vehicle target longitudinal force, the vehicle target lateral force, and the vehicle target yaw moment based on the vehicle target longitudinal acceleration, the vehicle target lateral acceleration, and the vehicle target yaw rate respectively.

45. The driving control method according to claim 25, further comprising controlling the driving force of all wheels, and controlling independently the braking force of each wheel.

46. The driving control method according to claim 45, further comprising controlling independently the driving force of each wheel, and the braking force of each wheel.

47. The driving control method according to claim 25, wherein the vehicle corresponds to a four-wheel vehicle having right and left-front wheels and right and left-rear wheels.