METHOD FOR OPERATING AN ELECTRICAL POWER STEERING MECHANISM

• US 20140214277A1
• Filed: 06/28/2012
• Published: 07/31/2014
• Est. Priority Date: 09/14/2011
• Status: Active Grant

• Current Assignee: Robert Bosch Automotive Steering GmbH (Robert Bosch GmbH)
• Original Assignee: ZF Lenksysteme GmbH (Robert Bosch GmbH)
• Inventors: Brenner, Peter
• Granted Patent: US 9,221,492 B2
• Time in Patent Office: Days
• US Class Current: 701/41
• CPC Class Codes: B62D 5/0484 for reaction to failures, e.g. limp home
• CPC Class Codes: B62D 5/049 detecting sensor failures
• CPC Class Codes: G06F 11/0796 Safety measures, i.e. ensuring safe condition in the event of error, e.g. for controlling element
• CPC Class Codes: G06F 11/1487 using N-version programming
• CPC Class Codes: G06F 11/1641 where the comparison is not performed by the redundant processing components
• CPC Class Codes: G06F 11/165 with continued operation after detection of the error

Abstract

A computer and function architecture for operating an electrical power-assisted steering system, comprises a control path and a monitoring path that has a diverse design in relation thereto and which are processed basically parallel to each other in each case on two associated cores of a redundant microcomputer, and arithmetic differences that occur within the control path or the monitoring path are detected at the functional level by way of a comparator, and the results of individual computing steps are detected at the granular level by way of a core comparator, and as a result of a detected difference of the comparator at the functional level, a transition is made into an emergency operating mode in the event that the core comparator has not diagnosed an arithmetic error, so as to ensure further availability of at least some of the steering assistance function or of the steering functions over at least a certain time period.

Claims

1. A computer and function architecture for operating an electrical power-assisted steering system, comprising a control path and a monitoring path that has a diverse design in relation thereto are processed basically parallel to each other in each case on two associated cores of a redundant microcomputer, and arithmetic differences that occur within the control path or the monitoring path are detected at the functional level by way of a comparator, and the results of individual computing steps are detected at the granular level by way of a core comparator), and as a result of a detected difference of the comparator at the functional level, a transition is made into an emergency operating mode in the event that the core comparator has not diagnosed an arithmetic error, so as to ensure further availability of at least some of the steering assistance function or of the steering functions over at least a certain time period.

2. The computer and function architecture for controlling an electrical power-assisted or servo steering system according to claim 1, wherein the emergency operating mode is implemented by way of a dedicated emergency operating program.

3. The computer and function architecture for controlling an electrical power-assisted or servo steering system according to claim 1, wherein the emergency operating mode operates according to one of the strategies listed below:

steering assistance is limited to a value that is designed to be reduced as compared to a normal value;

or

steering assistance is limited to a value that is designed to be reduced as compared to a normal value, wherein the reduction is made as a function of the situation and/or in a time-controlled manner by way of a ramp;

or

steering assistance is reduced to the value zero, wherein the reduction is made as a function of the situation and/or in a time-controlled manner by way of a ramp.

4. A control device, or combined engine/control device unit, comprising a computer and function architecture according to claim 1.

5. A power-assisted steering system, comprising a control device or a combined engine/control device unit, according to claim 4.