METHOD AND DEVICE FOR THE COMPENSATION OF STEERING WHEEL ROTARY OSCILLATIONS IN A STEERING SYSTEM

• US 20130124048A1
• Filed: 01/07/2013
• Published: 05/16/2013
• Est. Priority Date: 07/12/2010
• Status: Active Grant

• Current Assignee: Robert Bosch Automotive Steering GmbH (Robert Bosch GmbH)
• Original Assignee: Stefan Gruener
• Inventors: GRUENER, Stefan, Nierobisch, Thomas
• Granted Patent: US 9,002,583 B2
• Time in Patent Office: Days
• US Class Current: 701/42
• CPC Class Codes: B62D 5/0472 for damping vibrations
• CPC Class Codes: B62D 6/00 Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits means for initiating a change in direction B62D1/00; steering valves B62D5/06; combined with means for inclining the vehicle body or wheels on bends B62D9/00

Abstract

A torque actuator is regulated so as to permit an activation of the torque actuator such that steering wheel rotary oscillations that occur can be compensated. For this purpose, in one embodiment, a torsion bar torque is detected. A compensation torque is determined as a function of the detected torsion bar torque by means of a variable-frequency disturbance variable and state variable calculator. The compensation torque or a signal corresponding to the compensation torque is then taken into consideration during activation of the torque actuator.

Claims

1. A method for the compensation of steering wheel rotary oscillations during operation of a steering system in a vehicle, said steering system comprising an activatable torque actuator, wherein a current torsion bar torque is determined, a compensation torque is determined as a function of the current torsion bar torque, and the torque actuator is activated as a function of the compensation torque, wherein the torsion bar torque or a variable formed as a function of the torsion bar torque is fed to a variable-frequency disturbance variable and state variable calculator which contains a model of a sinusoidal disturbance and a model of the transmission behavior from a torque of the torque actuator and the compensation torque is determined by means of the variable-frequency disturbance variable and state variable calculator using the model of the disturbance.

2. The method according to claim 1, wherein, by means of the variable-frequency disturbance variable and state variable calculator, an amplitude and a phase of the steering wheel rotary oscillation are taken into account when determining the compensation torque.

3. The method according to claim 1, wherein a component of the steering wheel rotary oscillations that has already been compensated is to into account when determining the compensation torque.

4. The method according to claim 3, wherein the compensation torque is fed back to the variable-frequency disturbance variable and state variable calculator.

6. The method according to claim 1, wherein the model describes the transmission behavior at least in the frequency range relevant to the steering wheel rotary oscillations with regard to the amplitude response and with regard to the phase response.

7. The method according to claim 1, wherein the compensation torque is determined only if the existence of a steering wheel rotary oscillation is deduced by means of a testing process.

8. The method according to claim 7, wherein the existence of a steering wheel rotary oscillation is deduced if a vehicle speed, a wheel speed or a variable correlating with the wheel speed is within a predefinable range and the steering system is being operated at least substantially in a straight-ahead position.

9. The method according to claim 7, wherein the testing process comprises the evaluation of a current amplitude of the torsion bar torque, the amplitude preferably being determined by means of an estimating process.

10. The method according to claim 1, wherein the detected torsion bar torque is filtered and the filtered torsion bar torque is fed to the variable-frequency disturbance variable and state variable calculator to determine the compensation torque.

11. The method according to claim 10, wherein a variable bandpass filter is used as the filter, an excitation frequency is formed as a function of a vehicle speed, a wheel speed or a variable correlating with the wheel speed, and a center frequency of the variable bandpass filter is selected as a function of the excitation frequency.

12. The method according to claim 1, wherein the variable-frequency disturbance variable and state variable calculator is parameterized with regard to at least one variable and an adaptation of at least one function of the variable-frequency disturbance variable and state variable calculator in order to compensate deviations in series production and/or in order to compensate an aging of the steering system is performed by modifying the at least one parameter.

13. The method according to claim 12, wherein the at least one parameter is modified as a function of a determined compensation quality.

14. The method according to claim 13, wherein the compensation quality can be determined by evaluating an amplitude of a remaining residual oscillation in the torsion bar torque.

15. The method according to claim 1, wherein the adaptation of the variable-frequency disturbance variable and state variable calculator comprises at least an adaptation of the model of the transmission behavior.

16. The method according to claim 1, wherein the variable-frequency disturbance variable and state variable calculator is configured as an inseparable module which determines the compensation torque as a function of the torsion bar torque, wherein the variable-frequency disturbance variable and state variable calculator comprises in particular the model of the transmission behavior.

18. The device according to claim 17, wherein the device comprises means for carrying out a method according to claim 1.

5. (canceled)

17. A device for the compensation of steering wheel rotary oscillations during operation of a steering system in a vehicle, wherein the steering system (t) comprises an activatable torque actuator and means for determining a current torsion bar torque, and wherein the device comprises means for determining a compensation torque as a function of the current torsion bar torque and means for activating the torque actuator as a function of the compensation torque, wherein the device comprises a variable-frequency disturbance variable and state variable calculator, wherein the variable-frequency disturbance variable and state variable calculator, which contains a model of a sinusoidal disturbance and a model of the transmission behavior from a torque of the torque actuator, is designed to determine, using the model of the disturbance the compensation torque as a function of the torsion bar torque or of a variable formed as a function of the torsion bar torque.