Closed-loop control for trailer sway mitigation

• US 8,740,317 B2
• Filed: 08/11/2006
• Issued: 06/03/2014
• Est. Priority Date: 08/11/2006
• Status: Active Grant

• Current Assignee: Robert Bosch Corporation (Robert Bosch GmbH), Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Wu, Hsien-cheng, Nardi, Flavio, Chen, Jin-Jae, Hartman, Eric
• Primary Examiner(s): MOMPER, ANNA M
• Application Number:
  US11/503,875
• Publication Number:
  US 20080036296A1
• Time in Patent Office: 2,853 Days
• Field of Search: 303/7, 303/123, 303/140, 303146-147, 701/83
• US Class Current: 303/123
• CPC Class Codes: B60T 2230/06 Tractor-trailer swaying
• CPC Class Codes: B60T 8/1708 for lorries or tractor-trailer combinations
• CPC Class Codes: B60T 8/1755 Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve road vehicle drive control systems for control of driving stability otherwise than by controlling a particular sub-unit B60W30/02
• CPC Class Codes: B60W 2050/0009 Proportional differential [PD] controller
• CPC Class Codes: B60W 2050/001 Proportional integral [PI] controller
• CPC Class Codes: B60W 2050/0011 Proportional Integral Differential [PID] controller
• CPC Class Codes: B60W 2050/0031 Mathematical model of the vehicle
• CPC Class Codes: B60W 2050/0052 Filtering, filters
• CPC Class Codes: B60W 2300/14 Tractor-trailers, i.e. combinations of a towing vehicle and one or more towed vehicles, e.g. caravans; Road trains
• CPC Class Codes: B60W 2520/125 Lateral acceleration
• CPC Class Codes: B60W 2520/14 Yaw
• CPC Class Codes: B60W 2520/22 Articulation angle, e.g. between tractor and trailer
• CPC Class Codes: B60W 2520/28 Wheel speed
• CPC Class Codes: B60W 2540/18 Steering angle
• CPC Class Codes: B60W 2720/14 Yaw
• CPC Class Codes: B60W 40/11 Pitch movement
• CPC Class Codes: B60W 40/112 Roll movement
• CPC Class Codes: B60W 40/114 Yaw movement
• CPC Class Codes: B60W 50/0097 Predicting future conditions
• CPC Class Codes: B60W 50/06 Improving the dynamic response of the control system, e.g. improving the speed of regulation or avoiding hunting or overshoot

Abstract

A method, and a system using the method, of controlling a towing vehicle that is connected to a vehicle trailer. The method includes sensing a set of vehicle targets and a set of vehicle conditions in response to the set of vehicle targets. The method also includes determining a plurality of differences between the set of vehicle targets and the set of vehicle conditions, determining a trend of the plurality of differences, generating at least one of a symmetric signal and an asymmetric signal based on the trend, and actuating a vehicle system with the at least one of a symmetric signal and an asymmetric signal.

Claims

1. A method of controlling a towing vehicle connected to a vehicle trailer, the method comprising:

determining a set of vehicle targets for the towing vehicle, the set of vehicle targets including a plurality of target values each corresponding to a different one of a plurality of vehicle sensors positioned on the towing vehicle;

sensing a set of vehicle conditions indicative of movements exhibited by the towing vehicle caused by the vehicle trailer, the set of vehicle conditions including a plurality of condition values each sensed by a different one of the plurality of vehicle sensors;

determining a plurality of differences between the set of vehicle targets and the set of vehicle conditions;

determining a trend of the plurality of differences;

determining, by a symmetric braking control system, a symmetric force to apply to the vehicle based at least in part on the set of vehicle targets and the set of vehicle conditions;

determining, by an asymmetric braking control system, an asymmetric force to apply to the vehicle based at least in part on the set of vehicle targets and the set of vehicle conditions;

selecting between the symmetric control system and the asymmetric control system based on the trend; and

actuating a vehicle system according to the selected symmetric control system or the asymmetric control system to apply the symmetric force or the asymmetric force to the towing vehicle to decrease the plurality of differences.

2. The method of claim 1, wherein determining a trend of the plurality of differences comprises:

determining a rate of change of the plurality of differences as compared to a previous plurality of differences;

indicating the trend to be increasing when the rate of change comprises a positive value; and

indicating the trend to be decreasing when the rate of change comprises a negative value.

3. The method of claim 1, wherein determining a trend of the plurality of differences comprises:

determining a peak value from a previous plurality of differences;

indicating the trend to be increasing when one of the plurality of differences is above the peak value; and

indicating the trend to be decreasing when all of the plurality of differences are less than the peak value.

4. The method of claim 1, wherein selecting between the symmetric control system and the asymmetric control system comprises:

selecting the asymmetric control system when the trend indicates increasing differences, between the set of vehicle targets and the set of vehicle conditions; and

selecting the symmetric control system when the trend indicates decreasing differences between the set of vehicle targets and the set of vehicle conditions.

5. The method of claim 1, wherein actuating a vehicle system comprises applying at least one of a symmetric braking and an asymmetric braking based on the selected control system.

6. The method of claim 1, further comprising band-pass filtering the plurality of differences, and wherein determining a trend comprises determining a trend of the plurality of filtered differences.

7. The method of claim 1, wherein actuating a vehicle system comprises generating at least one of a symmetric torque and an asymmetric torque based on the selected control system.

8. A system for controlling a towing vehicle connected to a vehicle trailer, the system comprising:

a plurality of sensors positioned on the towing vehicle configured to sense a set of vehicle conditions indicative of movements exhibited by the towing vehicle caused by the vehicle trailer, the set of vehicle conditions including a plurality of condition values each sensed by a different one of the plurality of vehicle sensors;

a comparator configured to determine a plurality of differences between the set of vehicle conditions and a set of vehicle targets, the set of vehicle targets including a plurality of target values each corresponding to a different one of the plurality of vehicle sensors;

a trend module configured to determine a trend of the plurality of differences;

a symmetric control system configured to determine a symmetric force to apply to the vehicle based at least in part on the set of vehicle targets and the set of vehicle conditions;

an asymmetric control system configured to determine an asymmetric force to apply to the vehicle based at least in part on the set of vehicle targets and the set of vehicle conditions;

a switch configured to select between the symmetric control system and the asymmetric control system based on the trend; and

a vehicle system configured to be actuated by the selected control system to apply the symmetric force or the asymmetric force to the towing vehicle.

9. The system of claim 8, wherein the trend comprises a rate of change of the plurality of differences, and wherein the system is further configured to indicate the trend to be increasing when the rate of change comprises a positive value, and to indicate the trend to be decreasing when the rate of change comprises a negative value.

10. The system of claim 8, wherein the trend module comprises a peak seeker configured to determine a peak value of the plurality of differences, and wherein the controller is further configured to indicate the trend to be increasing when one of the plurality of differences is above a previously determined peak value, and to indicate the trend to be decreasing when all of the plurality of differences are less than the previously determined peak value.

11. The system of claim 8, wherein the switch is further configured to select the asymmetric control system when the trend indicates increasing differences between the set of vehicle conditions and the set of vehicle targets, and to select the symmetric control system when the trend indicates decreasing differences between the set of vehicle conditions and the set of vehicle targets.

12. The system of claim 8, wherein the vehicle system comprises a hydraulic braking system, and wherein the hydraulic braking system is configured to apply symmetric braking or asymmetric braking based on the selected control system.

13. The system of claim 8, further comprising a band-pass filter configured to filter the plurality of differences, and wherein the system is further configured to determine the trend of the plurality of differences based on the plurality of filtered differences.

14. The system of claim 8, wherein the vehicle system comprises a hydraulic system, and wherein the hydraulic system is configured to generate symmetric torque or asymmetric torque for the towing vehicle based on the selected control system.

15. A method of controlling a towing vehicle connected to a vehicle trailer, the method comprising:

determining a set of vehicle targets for the towing vehicle, the set of vehicle targets including a plurality of target values each corresponding to a different one of a plurality of vehicle sensors positioned on the towing vehicle;

sensing a set of vehicle conditions indicative of movements exhibited by the towing vehicle caused by the vehicle trailer, the set of vehicle conditions including a plurality of condition values each sensed by a different one of the plurality of vehicle sensors;

determining a plurality of differences between the set of vehicle targets and the set of vehicle conditions;

determining a trend of the plurality of differences;

determining a switching signal based on the trend; and

selectively applying either symmetric braking or asymmetric braking based on the switching signal to decrease the plurality of differences.

16. The method of claim 15, further comprising determining a model of the towing vehicle based on a plurality of dynamics, wherein the model comprises at least one of a proportional-integral-derivative (“

PID”

) controller model, a proportional controller model, a proportional-derivative (“

PD”

) controller model, a proportional-integral (“

PI”

) controller model, a filtering model, a trend model, a comparison model, and a peak seeking model.

17. The method of claim 16, further comprising:

determining a plurality of differences between the set of vehicle targets and the set of vehicle conditions with the comparison model;

determining a peak value of the plurality of differences with the peak seeking model;

filtering the plurality of differences with the filtering model;

determining the trend of the plurality of differences with the trend model; and

determining the switching signal with one of the PID controller model, the proportional controller model, the PD controller model, and the PI controller model.

18. The method of claim 16, wherein the plurality of dynamics of the towing vehicle comprise a wheel speed, a steering angle, a yaw rate, a body slip angle, a lateral acceleration, a front wheel torque, and a rear wheel torque.

19. The method of claim 15, further comprising:

determining a peak value from a previous plurality of differences;

indicating an increasing trend when one of the plurality of differences is above the peak value; and

indicating a decreasing trend when all of the plurality of differences are less than the peak value.

20. The method of claim 19, wherein determining the switching signal comprises:

generating an asymmetric signal when the trend comprises an increasing trend; and

generating a symmetric signal when the trend comprises a decreasing trend.

21. The method of claim 15, further comprising:

determining a rate of change of the plurality of differences;

indicating an increasing trend when the rate of change comprises a positive value; and

indicating a decreasing trend when the rate of change comprises a negative value.

22. The method of claim 15, wherein selectively applying at least one of a symmetric braking and an asymmetric braking comprises generating at least one of a symmetric torque and an asymmetric torque.

23. The method of claim 15, further comprising

determining, by a symmetric braking control system, a symmetric force to apply to the vehicle based at least in part on the set of vehicle targets and the set of vehicle conditions;

and

determining, by an asymmetric braking control system, an asymmetric force to apply to the vehicle based at least in part on the set of vehicle targets and the set of vehicle conditions,

wherein determining a switching signal based on the trend includes determining a switching signal that switches between the symmetric braking control system and the asymmetric braking control system, and

wherein selectively applying either symmetric braking or asymmetric braking includes controlling a vehicle system according to either the symmetric braking control system or the asymmetric braking control system based on the switching signal.

24. The method of claim 23, wherein the symmetric braking control system is a first proportional-integral-derivative (“

PID”

) controller and the asymmetric braking control system is a second proportional-integral-derivative (“

PID”

) controller.