Apparatus and method for producing a desired return torque in a vehicle power steering system having a rotational steering position sensor
US6050360A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 24, 1998 |
| Grant date | Apr 18, 2000 |
| Priority date | — |
| Expiry date | Jun 24, 2018 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB62D15/0245
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A vehicle power steering system has a steering shaft with a rotational position sensor providing signal rollover so that each sensor output indicates a plurality of potential absolute steering positions separated from each other by multiples of a rollover angle. Upon each initiation of vehicle operation, the system selects, as an unadjusted steering position, one of the plurality of absolute steering positions corresponding to an initial sensor output; and the system repeatedly updates the unadjusted steering position in response to sensor output changes, including sensed rollover events. The system repeatedly tests a set of revolution offsets with the updated unadjusted steering position and excludes any which indicate an out-of-range absolute steering position. The final remaining revolution offset is latched as the correct value. Preferably, a temporary value of revolution offset used with the unadjusted position during the testing provides a return or centering torque of zero; and, once the final value is latched, the temporary value is walked incrementally toward the final value, when the return torque value is in the correct centering direction, to avoid a sudden increase in …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.