Dual mode servo
US4574227A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 14, 1983 |
| Grant date | Mar 4, 1986 |
| Priority date | — |
| Expiry date | Nov 14, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05B2219/42171
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A dual mode, digital servo positioning system controls servo motor current by a processor-generated current control set point in conjunction with velocity feedback. When the motor has advanced to the vicinity of a target position, the processor opens the velocity feedback loop and reduces servo amplifier gain, such that the set point controls motor current without velocity feedback. This open loop condition provides a springy servo response that eliminates oscillation due to small deviations from target position caused by electronic drift or gravity. Position information is provided to the processor by means of quadrature encoded tachometer pulses from the motor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.