Apparatus and method for controlling an electric motor
US6448731B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 28, 2000 |
| Grant date | Sep 10, 2002 |
| Priority date | — |
| Expiry date | Jul 28, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P21/22
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
An electric assist steering system (10) includes a torque sensor (16) that provides an applied torque signal (24) indicative of applied steering torque. A motor position sensor (36) provides a motor position signal (40) indicative of the relative position between the rotor and the stator of an AC permanent magnet electric assist motor (22). A first controller (26) controls energization of the electric assist motor and a second controller (54) calculates a DQ vector value in response to applied steering torque and motor position. The second controller (54) also transforms the monitored motor current and position into DQ values. The second controller (54) compares the DQ values responsive to applied steering torque with the DQ value from monitored motor current and position. The electric assist motor (22) is disabled if the comparison indicates inconsistent results.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.