Electric power steering system
US7481294B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 26, 2005 |
| Grant date | Jan 27, 2009 |
| Priority date | — |
| Expiry date | Feb 24, 2027 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB62D15/0245
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
The CPU calculates axial force matching external force that acts on a rack bar by combining steering torque MT that acts on a steering shaft with assist torque AT generated by an electric motor. The CPU then determines whether a vehicle is running straight based on a steering angle θ, a vehicle speed V, and the axial force F. Thus, even in a state where a control steering angle midpoint is deviated and a driver applies torque so as to return a turning position of a steering wheel to a neutral position, whether the vehicle is running straight can be accurately determined by making a determination by using the axial force F that acts on the rack bar. The CPU can set a considerably accurate control steering angle midpoint by calculating a smoothed steering angle midpoint by using an instantaneous steering angle midpoint in an accurately determined straight-running state.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.