Electric power steering apparatus
US5912539A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 30, 1997 |
| Grant date | Jun 15, 1999 |
| Priority date | — |
| Expiry date | Dec 30, 2017 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB62D5/049
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
An electric power steering apparatus includes a judgment unit which passes a judgment that a condition, in which an offset signal indicative of the offset between a target current signal and a motor current signal, or a drive control signal used for controlling an electric motor is greater than a threshold, has continued for an allowable time. Based on this judgment, a forced drive control unit forcibly drives the electric motor. A fault judgment unit monitors the motor current in all times and judges a current detecting unit to be at fault if the motor current does not vary even though the electric motor is drive forcibly. Thus, even when a failure in the current detecting unit occurs during movement of a motor vehicle, such failure can reliably be detected. Additionally, since the judgment is performed after the electric motor is driven forcibly, misjudgment does not occur even when the judgement at the judgment unit results from continuous application of abrupt manual steering operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.