Method and device for controlling driving dynamics

• US 6,865,461 B2
• Filed: 03/17/2003
• Issued: 03/08/2005
• Est. Priority Date: 03/15/2002
• Status: Active Grant

• Current Assignee: Volkswagen AG
• Original Assignee: Volkswagen AG
• Inventors: Neef, Barbara, Berkner, Stefan, Duda, Holger
• Primary Examiner(s): Beaulieu, Yonel
• Application Number:
  US10/390,852
• Publication Number:
  US 20040007412A1
• Time in Patent Office: 722 Days
• Field of Search: 701/41, 280/5.5, 280/5.51, 477/1, 180/6.2
• US Class Current: 701/41
• CPC Class Codes: B60G 2400/204 Vehicle speed
• CPC Class Codes: B60G 2400/41 Steering angle
• CPC Class Codes: B60G 2600/02 Retarders, delaying means, dead zones, threshold values, cut-off frequency, timer interruption
• CPC Class Codes: B60G 2600/1873 Model Following
• CPC Class Codes: B60G 2800/70 Estimating or calculating vehicle parameters or state variables
• CPC Class Codes: B60G 2800/702 Improving accuracy of a sensor signal
• CPC Class Codes: B60G 2800/96 ASC - Assisted or power Steering control
• CPC Class Codes: B60G 2800/962 Four-wheel steering
• CPC Class Codes: B60T 2230/02 Side slip angle, attitude angle, floating angle, drift angle
• CPC Class Codes: B60T 2260/02 Active Steering, Steer-by-Wire
• CPC Class Codes: B60T 2260/022 Rear-wheel steering; Four-wheel steering
• CPC Class Codes: B60T 2270/86 Optimizing braking by using ESP vehicle or tire model
• CPC Class Codes: B60W 2050/0031 Mathematical model of the vehicle
• CPC Class Codes: B60W 2050/0052 Filtering, filters
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2520/14 Yaw
• CPC Class Codes: B60W 2540/18 Steering angle
• CPC Class Codes: B62D 6/04 responsive only to forces disturbing the intended course of the vehicle, e.g. forces acting transversely to the direction of vehicle travel
• 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
• CPC Class Codes: G05B 17/02 electric

Abstract

In a method and device for controlling driving dynamics, at least one steering action at a vehicle axle being controlled, a driving-dynamics setpoint, which is described by at least a yaw-dynamics setpoint, being ascertained, a steering-angle precontrol value being determined on the basis of the driving-dynamics setpoint, using a model of the controlled system, the driving state, which is described by at least the yaw rate, being ascertained, at least one steering-angle correction value being ascertained, based on the deviation of the actual yaw rate from a setpoint yaw rate, and the steering action being defined by the steering-angle precontrol value and the at least one steering-angle correction value.

Claims

1. A method for controlling driving dynamics, comprising:

controlling at least one steering action of a vehicle axle;

ascertaining a driving-dynamics setpoint described by at least a yaw-dynamics setpoint;

determining a steering-angle precontrol value in accordance with the driving-dynamics setpoint using a model of a controlled system;

ascertaining a driving state at least described by a yaw rate;

determining at least one steering-angle correction value in accordance with a deviation of the yaw rate from a setpoint yaw rate; and

defining the steering action in accordance with the steering-angle precontrol value and the at least one steering-angle correction value.

2. The method according to claim 1, wherein the driving-dynamics setpoint ascertaining step includes calculating the driving-dynamics setpoint as a function of a predetermined steering angle and a current vehicle speed using the model of the controlled system.

3. The method according to claim 1, wherein the steering-angle precontrol determining step includes an inversion of the controlled system.

4. The method according to claim 3, wherein the model of the controlled system includes a linear, single-track model without consideration of dynamic tire effects.

5. The method according to claim 3, wherein the model of the controlled system includes a linear, single-track model including dynamic tire effects.

6. The method according to claim 1, further comprising:

providing a steering action at at least two vehicle axes, the driving-dynamics setpoint including at least the yaw-dynamics setpoint and a sideslip-angle dynamics setpoint, a description of the driving state including at least a sideslip angle and a yaw rate; and

determining a second steering-angle correction value in accordance with a deviation of the sideslip angle from a setpoint sideslip angle.

7. The method according to claim 6, further comprising determining the sideslip angle including calculation of a first sideslip angle by solving at least one of a linear and a linearized, first-order differential equation, calculation of a second sideslip angle by solving a nonlinear, first-order differential equation and fusion of the calculated first sideslip angle and second sideslip angle to form an estimated value.

8. The method according to claim 7, wherein the fusion includes a weighted addition.

9. The method according to claim 7, wherein the nonlinear differential equation is solved in the sideslip angle determining step by numerical integration, the nonlinear differential equation expanded by at least a filter term.

10. A device for controlling the driving dynamics of a vehicle, comprising:

control elements configured to perform a steering action at at least one axle;

a first processing unit configured to ascertain a driving-dynamics setpoint at least described by a yaw-dynamics setpoint;

a second processing unit configured to calculate a steering-angle precontrol value in accordance with the driving-dynamics setpoint and a model of a controlled system;

a driving-state monitor configured to ascertain a driving state at least described by a yaw rate;

a control unit configured to ascertain at least one steering-angle correction value adapted to control yaw dynamics in accordance with a deviation of the yaw rate from a setpoint yaw rate; and

a third processing unit configured to define the steering action in accordance with the steering-angle precontrol value and the at least one steering-angle correction value.

11. The device according to claim 10, wherein the first processing unit is configured to calculate the driving-dynamics setpoint as a function of a given steering angle and a current vehicle speed in accordance with a desired model of the controlled system.

12. The device according to claim 10, wherein the second processing unit is configured to invert the controlled system.

13. The device according to claim 12, wherein each of the first processing unit and the second processing unit is configured to model the controlled system as a linear, single-track model without consideration of dynamic tire effects.

14. The device according to claim 12, wherein each of the first processing unit and the second processing unit is configured to model the controlled system as a linear, single-track model including dynamic tire effects.

15. The device according to claim 10, wherein the vehicle includes control elements configured to perform steering action at at least two vehicle axes, the first processing unit configured to ascertain at least the yaw-dynamics setpoint and a sideslip-angle dynamics setpoint, the driving-state monitor configured to ascertain at least one sideslip angle and the yaw rate, the control unit configured to ascertain a second steering-angle correction value in accordance with a deviation of the sideslip angle from a setpoint sideslip angle.

16. The device according to claim 15, wherein the driving-state monitor is configure to perform a sideslip-angle estimation including a calculation of a first sideslip angle by solving at least one of a linear and a linearized, first-order differential equation, a calculation of a second sideslip angle by solving a nonlinear, first-order differential equation and a fusion of the calculated first and second sideslip angles to form an estimated value.

17. The device according to claim 16, wherein the fusion includes a weighted addition.

18. The device according to claim 16, wherein the driving-state monitor is configured to solve the nonlinear differential equation by numerical integration, the nonlinear differential equation expanded by at least a filter term.

19. A device for controlling driving dynamics of a vehicle, comprising:

means for performing a steering action at at least one axle;

means for ascertaining a driving-dynamics setpoint at least described by a yaw-dynamics setpoint;

means for calculating a steering-angle precontrol value in accordance with the driving-dynamics setpoint and in accordance with a model of a controlled system;

means for ascertaining a driving state at least described by a yaw rate;

means for ascertaining at least one steering-angle correction value for controlling yaw dynamics in accordance with a deviation of the yaw rate from a setpoint yaw rate; and

means for defining the steering action in accordance with the steering-angle precontrol value and the at least one steering-angle correction value.