Power steering apparatus
US7642738B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 28, 2007 |
| Grant date | Jan 5, 2010 |
| Priority date | — |
| Expiry date | Jun 30, 2028 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB62D5/0496
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A power steering apparatus includes an electric motor, a temperature sensor, and a control unit. The electric motor produces an assist steering effort in a steering system. The temperature sensor measures a temperature of a first portion subject to thermal influence of operation of the electric motor. The control unit determines an estimated temperature of a second portion in accordance with a value of a motor current, the second portion being subject to thermal influence of operation of the electric motor. The control unit determines a first upper limit value in accordance with the measured temperature; determines a second upper limit value in accordance with the estimated temperature; limit the motor current to a smaller one of the first and second upper limit values, when determining that the temperature sensor is normal; limit the motor current to the second upper limit value, when determining that the temperature sensor is abnormal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.