System and Method for Controlling Vehicle

• US 20090037069A1
• Filed: 06/06/2007
• Published: 02/05/2009
• Est. Priority Date: 06/07/2006
• Status: Active Grant

• Current Assignee: Advics Company Limited (Aisin Corp.), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Inoue, Gen, Ishida, Yasuhito
• Granted Patent: US 8,510,011 B2
• Time in Patent Office: Days
• US Class Current: 701/94
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/184 with wheel brakes
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2552/15 Road slope, i.e. the inclination of a road segment in the longitudinal direction
• CPC Class Codes: B60W 2710/0644 Engine speed
• CPC Class Codes: B60W 2710/105 Output torque
• CPC Class Codes: B60W 2720/10 Longitudinal speed
• CPC Class Codes: B60W 2720/28 Wheel speed
• CPC Class Codes: B60W 2720/30 Wheel torque
• CPC Class Codes: B60W 30/143 Speed control B60W30/16 takes precedence

Abstract

A system for controlling a vehicle that controls driving force and braking force such that a vehicle speed is maintained at a target vehicle speed. More specifically, when the vehicle speed exceeds the target vehicle speed, the system for controlling a vehicle maintains the driving force at or above a predetermined value, and applies braking force to the vehicle such that the vehicle speed is maintained at the target vehicle speed. This provides the vehicle with sufficient driving force for uphill driving following the downhill driving, and thus to travel uphill without significant speed loss. In other words, the vehicle ascends the uphill road smoothly at an approximately constant speed.

Claims

1. A system for controlling a vehicle comprising:

a control unit that maintains driving force applied to the vehicle at or above a predetermined value when a vehicle speed exceeds a target vehicle speed and that applies a braking force to the vehicle such that the vehicle speed is maintained at the target vehicle speed.

2. The system for controlling a vehicle according to claim 1, wherein the control unit maintains the driving force applied by the driving force control unit at a first driving force that is a level such that at least the vehicle maintains the same position on an uphill incline without applying the brake force.

3. The system for controlling a vehicle according to claim 2, wherein the control unit maintains the driving force applied by the driving force control unit at a sum of the first driving force and a second driving force determined based on the target vehicle speed.

4. The system for controlling a vehicle according to claim 2, further comprising:

a sensor for detecting gradient of a slope on which the vehicle travels,

wherein the driving force, such that the vehicle travels with no braking force applied, is determined based on the gradient of the slope detected by the sensor.

5. The system for controlling a vehicle according to claim 3, wherein the driving force is calculated in accordance with the relationship between a current engine speed and a target engine speed, the target engine speed being obtained from the target vehicle speed.

6. The system for controlling a vehicle according to claim 1, wherein when a wheel speed exceeds a target wheel speed, the control unit applies the braking force to the wheel whose speed exceeds the target wheel speed.

7. The system for controlling a vehicle according to claim 6, wherein when the wheel speed exceeds the target wheel speed by at least a prescribed amount, the control unit applies the braking force to the wheels.

8. The system for controlling a vehicle according to claim 6, wherein the target wheel speed is determined based on the lower of either the vehicle speed or the target vehicle speed.

9. A method for controlling a vehicle comprising:

maintaining driving force applied to the vehicle at or above a predetermined value when a vehicle speed exceeds a target vehicle speed; and

applying braking force to the vehicle such that the vehicle speed is maintained at the target vehicle speed.

10. The method for controlling a vehicle according to claim 9, wherein the driving force is maintained at a first driving force that is a level such that at least the vehicle maintains the same position on an uphill incline without applying the brake force.

11. The method for controlling a vehicle according to claim 10, wherein the driving force is maintained at a sum of the first driving force and a second driving force determined based on the target vehicle speed.

12. The method for controlling a vehicle according to claim 10, further comprising:

detecting a gradient of a slope on which the vehicle travels,

wherein the first driving force is determined based on the gradient of the slope detected by the sensor.

13. The method for controlling a vehicle according to claim 11, wherein the driving force, determined based on the target vehicle speed, is calculated in accordance with the relationship between a current engine speed and a target engine speed, wherein the target engine speed is obtained from the target vehicle speed.

14. The method for controlling a vehicle according to claim 9, wherein when a wheel speed exceeds a target wheel speed, the braking force is applied to the wheel whose speed exceeds the target wheel speed.

15. The method for controlling a vehicle according to claim 14, wherein when the wheel speed exceeds the target wheel speed by at least a prescribed amount, the braking force is applied to the wheel.

16. The method for controlling a vehicle according to claim 14, wherein the target wheel speed is determined based on the lower of either the vehicle speed or the target vehicle speed.

17. (canceled)