Motor drive apparatus and electric power steering apparatus
US7187154B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Apr 27, 2005 |
| Grant date | Mar 6, 2007 |
| Priority date | — |
| Expiry date | Apr 27, 2025 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB62D5/046
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
The present invention provides a motor drive apparatus capable of calculating an angular velocity and a rotation angle accurately in the entire rotation velocity range of a motor using a cheap Hall sensor having an inferior accuracy without using an expensive resolver having a high accuracy. The present invention includes a first angular velocity calculating means for calculating the angular velocity based on the back-EMF of the motor when it rotates at low speeds and a second angular velocity calculating means for calculating the angular velocity based on a signal from the Hall sensor when it rotates at high speeds. According to the present invention, the angular velocity and rotation angle can be calculated accurately in the entire rotation speed range using the Hall sensor under hybrid usage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.