Detection of the angular position of the rotor of a brush motor without using sensors
US8169178B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 29, 2009 |
| Grant date | May 1, 2012 |
| Priority date | — |
| Expiry date | Oct 18, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P7/0094
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method of detecting an angular position of a rotor of a motor includes detecting switching ripple peaks and armature current disturbance peaks using a peak detector configured to generate a square wave having edges coinciding with detected peaks. The method further includes filtering the square wave in a time domain by generating an integration ramp, toward a set value, of an estimated ripple frequency for an interval of time based on the estimated ripple frequency. An enablement range is established to reset the integration ramp by setting a threshold below and above the set value and a time window centered on an end time of each period of the estimated ripple frequency. The method further includes resetting the integration ramp, and updating the estimated ripple frequency based upon a period determined by a time of the resetting, if an edge of the square wave is within the time window.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.