Computer generated cavity length control with automatic gain control for ring laser gyros
US5074664A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 11, 1991 |
| Grant date | Dec 24, 1991 |
| Priority date | — |
| Expiry date | Jan 11, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01C19/665
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A ring laser gyro having a ring laser that preferably has four legs and four corner mirrors. At least one of the corner mirror is partly transmissive, and the transmitted beam is sensed and converted into a digital signal. The digital signal is fed back in two computer loops to at least one digital-to-analog converter, and thence to a transducer which drives at least one corner mirror inward and outward. One of the computer loops includes a stepped demodulator having four steps per cycle. The steps have voltages at the operating voltage of the transducer, that voltage plus an increment, the operating voltage, and that voltage less a decrement. The first loop sends an operating voltage to the digital-to-analog converters. The second loop demodulates the beam signal at a second harmonic of the demodulation of the first loop to produce a voltage signal which controls the amplitude of dithering of the movable mirrors. A stepped modulator, in synchronism with the demodulator of the first loop, delivers a modulation signal to the digital-to-analog converters to step the movable mirrors. The operating voltage moves the mirrors into a position wherein the laser cavity operates at its inten…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.