Phase-responsive angular tracking device
US4857926A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 25, 1987 |
| Grant date | Aug 15, 1989 |
| Priority date | — |
| Expiry date | Aug 25, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/208
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus for generating phase modulated angular positional signals in digital form. A phase tracking loop receives a phase modulated signal from the rotor of a resolver whose stator windings are excited in quadrature. The phase output of the resolver is proportional to the angular displacement of the rotor. Signals for exciting the stator windings of the resolver are applied in phase quadrature to a phase detector to develop an analog error signal when combined with the rotor output signal. The analog phase error signal provides an output indicative of the angular displacement of the rotor. The error signal is applied to a voltage controlled oscillator, converted to digital form, and combined with the excitation signals in a closed loop to force the error signal to a null, whereupon the indicated digital output angle is in coincidence with the angular displacement of the rotor shaft.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.