Frequency division multiplexing type paralleling laser length measuring instrument

Abstract

A frequency-division multiplex-typed concurrent laser length-measuring instrument relates to the technical field of a laser length-measuring method, a three-dimensional measuring method and a laser three-dimensional imaging method. The length-measuring instrument uses a novel method of multi-channel frequency-division multiplexing modulation and synchronous phase detection concurrent length-measuring, uses DDS technique to realize the multi-channel laser frequency-division multiplexing sine modulation, uses a FFT calculating method to conduct the phase detection of the multi-channel synthetic signals, and then gains the distances of each point. The invention has the advantages that: the length-measuring instrument makes full use of the frequency-division concurrent multi-channeled modulation, adopts a single-channeled photoelectric receiver to receive the multi-channel diffusely reflected laser modulation signals, and uses DSP high-speed digital Fourier transforming technology to realize the synthetic digital phase-detecting function of multi-channel signals, thus the concurrent phase-detection length-measuring by multi-channel laser is realized, and the speed and efficiency of the length-measuring is greatly improved.

Description

technical field [0001] The invention relates to the technical field of a laser length measurement method, a three-dimensional measurement method and a laser three-dimensional imaging method, in particular to a frequency division multiplexing type parallel laser length measuring instrument. Background technique [0002] The existing phase laser length measuring instrument mainly uses the control and processing unit to control the Direct Digital Synthesizer (DirectDigital Synthesizer; DDS) to generate a laser modulation signal. The light reaches the same photoelectric receiver and is mixed with the local oscillator signal generated by DDS to obtain a ranging signal with a sine wave phase delay. After passing through the phase detector circuit, the phase difference of the laser at the measured point is obtained, so as to measure the round-trip of the laser. Time, and further calculate the distance between the measured point and the rangefinder. [0003] The disadvantages of th...

AI Technical Summary

Problems solved by technology

[0003] The disadvantages of the above-mentioned phase laser length measuring instruments are: single-beam emission and single-beam reception are adopted, the measurement speed is slow, and the accuracy of phase detection is low; If the time-division multiplexing technology is used to realize the time-sharing work of multiple length measuring instruments, the measurement system will be large in size, high in power consumption, and complex in system, which cannot meet the requirements of three-dimensional measurement

Images