Laser-based measurement system
US4895440A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 22, 1988 |
| Grant date | Jan 23, 1990 |
| Priority date | — |
| Expiry date | Aug 22, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S17/14
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A laser beam three dimensional position measurement system includes a laser transmitter mounted at a stationary reference position at a work site and a receiver mounted on a mobile machine at the site. The transmitter produces a laser reference plane by sweeping a laser beam about the transmitter. The receiver includes a retroreflector which intercepts and reflects laser energy back to the transmitter when the laser beam sweeps past the retroreflector. The system also includes at the transmitter a circuit composed of a photodetector, timer, clock and counter. The photodetector senses laser energy reflected back to the transmitter from the retroreflector. The timer modulates the laser beam produced by the transmitter in response to detection of the beam. The counter is connected to the clock and timer, and is enabled by the timer to start counting electrical pulses received from the clock when the beam is modulated. The counter is disabled to stop counting electrical pulses when the modulation is detected. The number of pulses counted by the counter is indicative of the range of the receiver from the transmitter. The orientation of the beam relative to a fixed reference axis at the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.