Brushless motor speed control system
US9190940B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 6, 2009 |
| Grant date | Nov 17, 2015 |
| Priority date | — |
| Expiry date | Jan 23, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P2209/07
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
This system provides a wide range of smooth and precisely controlled low and high speeds for pan-tilt-zoom surveillance cameras, in which a brushless motor is controlled by a Microcontroller in a low speed mode by sinusoidal synchronous commutation, in a high speed mode by block commutation, and in a transition phase from the low speed mode to the high speed mode by modulating integrated pulse-width modulation (PWM) square waves with sine waves. PID and lookup table registers are used by a microcontroller for a smooth transition from high speed mode to low speed mode, and from low speed mode to high speed mode, phase locking a sine position during transitions, in order to give a surveillance camera an ability to quickly move from one target to another at up to 100 degrees per second yet track objects that are moving very slowly.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.