Stepper motor gauge calibration by AC feedback
US5783939A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 26, 1996 |
| Grant date | Jul 21, 1998 |
| Priority date | — |
| Expiry date | Jul 26, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P8/22
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A high frequency AC probe signal is applied to one coil of a stepper motor to induce a signal on the other coil. The induced signal varies in amplitude according to rotor position. The stepper motor is driven by a microprocessor in microsteps. The position of a mechanical stop is determined by monitoring the induced signal while driving the rotor to the stop. When the induced signal no longer changes in amplitude the number of the last microstep yielding movement is recorded as the rotor position corresponding to the stop position. Also by measuring the induced signal at each microstep over a whole rotor rotation and the signal when the rotor stops, a more precise value of the stop position is determined by interpolation. Alternatively, the flip back position of the gauge and thus the stop position is determined on the basis of the induced signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.