System and method for measuring angular position
US5596403A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 2, 1994 |
| Grant date | Jan 21, 1997 |
| Priority date | — |
| Expiry date | Dec 2, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01C1/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system for measuring relative angular position about a roll-axis, a yaw-axis, and a pitch-axis includes a source assembly and a receiver assembly. A source assembly emits a rotationally polarized carrier wave laser beam. A laser beam from a laser diode is directed through a linear polarizer and then through the center of a rotating half-wave plate. The plate is secured to a hollow shaft of an electric motor. The beam travels through the plate and through the hollow shaft. A reference signal corresponding to the rotational modulation imposed by the rotating plate is obtained using a flag which is secured to the shaft and positioned to actuate an optical encoder. After leaving the source assembly and reaching the receiver assembly, the beam travels through another linear polarizer, a neutral density filter, and an aplanatic achromatic lens to a two-dimensional position sensing detector. In response to the beam, the position sensing detector produces output signals that correspond to the position of the beam. The signals are routed to a microprocessor by way of additional electronics. The microprocessor also receives the reference signal from the optical encoder adjacent the rotatin…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.