Method and device for adapting the boost rate of a steering system of a motor vehicle during tire pressure loss

• US 20150251694A1
• Filed: 03/04/2015
• Published: 09/10/2015
• Est. Priority Date: 03/04/2014
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: WAGNER, Marcus
• Granted Patent: US 9,266,561 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B62D 15/026 combined with automatic distance control, i.e. electronic tow bar
• CPC Class Codes: B62D 5/008 Changing the transfer ratio between the steering wheel and the steering gear by variable supply of energy, e.g. by using a superposition gear
• CPC Class Codes: B62D 5/0481 monitoring the steering system, e.g. failures
• CPC Class Codes: B62D 5/0484 for reaction to failures, e.g. limp home
• CPC Class Codes: B62D 6/001 the torque NOT being among the input parameters
• CPC Class Codes: B62D 6/002 computing target steering angles for front or rear wheels B62D7/159 takes precedence

Abstract

A method for adapting the boost factor of a steering system of a motor vehicle during tire pressure loss, in which the occurrence of a tire pressure loss is ascertained, the intensity of the pressure loss exceeding a specified threshold value, and in the presence of a pressure loss exceeding the threshold value, the boost factor of the steering system is reduced.

Claims

1. A method for adapting a boost rate of a steering system of a motor vehicle during tire pressure loss, the method comprising:

ascertaining an occurrence of a tire pressure loss, wherein the intensity of the pressure loss exceeds a specified threshold value; and

reducing, if the pressure loss exceeds the threshold value, the boost factor of the steering system.

2. The method of claim 1, wherein the reduction over time of the boost factor takes place according to a specified function.

3. The method of claim 1, wherein the reduced boost factor is maintained during a time interval of specified length.

4. The method of claim 1, wherein the reduced boost factor is retained until a stable driving state of the motor vehicle is detected.

5. The method of claim 1, wherein the reduced boost factor is retained until the vehicle longitudinal speed falls below a specified threshold value.

6. The method of claim 3, wherein after the expiration of the time interval of specified length and the reaching of a stable driving state or the falling below a specified threshold value by the vehicle'"'"'s longitudinal speed, the boost factor is raised again over time according to a specified function.

7. The method of claim 6, wherein the value, raised again, of the boost factor is less than the standard value of the boost factor when there is no tire pressure loss present.

8. The method of claim 1, wherein the steering system is a power steering system or an active steering system.

9. The method of claim 1, wherein the threshold value for the pressure loss is selected to be so high that, when it is exceeded, a nearly pressure-less tire or a burst tire is present.

10. The method of claim 1, wherein the driver is informed on the reduction of the boost factor.

11. The method of claim 1, wherein the reduction over time of the boost factor takes place according to a specified function, which is a linear function.

12. A device for adapting a boost rate of a steering system of a motor vehicle during tire pressure loss, comprising:

an ascertaining arrangement to ascertain an occurrence of a tire pressure loss, wherein the intensity of the pressure loss exceeds a specified threshold value; and

a reducing arrangement to reduce, if the pressure loss exceeds the threshold value, the boost factor of the steering system.