Motor-driven power steering system having a stable output torque
US4614248A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 8, 1984 |
| Grant date | Sep 30, 1986 |
| Priority date | — |
| Expiry date | Aug 8, 2004 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB62D5/0463
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
An electric motor driven power steering system is provided. The motor is prevented from operating at low torque command levels. After a first predetermined level of command torque is reached, the motor is controlled to generate torque at a predetermined rate less than the torque actually commanded by the vehicle driver. After a second predetermined level of commanded torque is reached, the motor is controlled to generate torque in accordance with the level of torque command. Thus, the phenomenon known as "hunting" and instability of the system at low torque levels are virtually eliminated. The system operates smoothly over its full range of operation and is not affected by rough road surface conditions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.