Electromagnetic actuator system using stepper motor with closed loop position sensing, electronic commutation and dynamic position and anomaly correction
US4618808A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 30, 1985 |
| Grant date | Oct 21, 1986 |
| Priority date | — |
| Expiry date | Jan 30, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P8/22
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Using as an actuator a stepper motor operated in a position-sensed closed loop mode via an electronic commutator by position and anomaly corrected motion control signals provided by a programmable logic array and by a microprocessor, provides a precision power positioner. The correct enabling of the motor coils, based on position sensing of the motor phase, using electronic commutation for the stepper motor, transforms the problem of enabling coil selection to the programmable logic array, which by its logic provides a simplified operating control as a function of present armature position feedback, and by a microprocessor corrects for anomalies such as temperature rise, square-law, and phase increase as a function of position desired and present armature position feedback signals, and thus provides high positional accuracy, high speed and force (torque) control independent of the motor cardinal step positions. A standard three phase magnetic resistor sensor is used both to sense the motor phase and to feed back the motor position to the microprocessor for calculation of corrections; actual control of the stepper motor is communicated as a single amplitude modulated control signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.