Improvement Of Frequency Modulated Continuous Wave Laser Ranging System And Research On Its Coordinate Measurement

The frequency modulated continuous wave laser ranging is a stable beat frequency signal formed by the frequency linearly modulated transmitting signal and the echo signal,and then the frequency information of the beat frequency signal is extracted to calculate the target distance information to be measured.Compared with other laser ranging methods,this method has higher ranging accuracy and resolution,larger ranging range,and can achieve non-contact and non-cooperative target measurement,so it is subject to large-scale measurement.A wide range of applications.At present,how to improve the ranging accuracy and resolution of the ranging system is one of the important research directions in the field of laser ranging.The main work of this paper is as follows:1.The measurement principle of frequency modulated continuous wave laser ranging technology is studied.The influence of the tuning nonlinearity of the laser on the ranging accuracy and resolution is analyzed.A double interference optical path frequency modulation continuous wave laser ranging system is built and used based on the extreme value.The frequency sampling method of the point corrects the tuning nonlinearity of the laser.On this basis,the influence of the resampling clock signal noise problem on the dual optical path FMCW laser ranging system is studied.2.A new equal-frequency subdivision resampling method is proposed to increase the system ranging range.At the same time,the required auxiliary fiber length can be reduced while the distance to be measured is constant.And aiming at the problem that the existing frequency extraction algorithm is not accurate or the calculation amount is too large,an equal optical frequency phase frequency measurement algorithm is proposed.In order to prove that the algorithm can meet the requirements of real-time high-precision measurement,through experiments,the algorithm is compared with several commonly used algorithms.3.Aiming at the Doppler effect introduced by the vibration of the measured target,a Doppler effect compensation correction method based on single-frequency laser is proposed.This method introduces a single-frequency laser as the auxiliary laser to detect the vibration on-line and measure the waveform.The signal is used to compensate the Doppler effect introduced by the vibration in the swept interference ranging.The simulation and experimental results show that the method can effectively eliminate the influence of the Doppler effect on the signal spectrum.And combining the high-precision two-dimensional turntable,the corresponding spherical coordinate system is established according to the turntable,and the three-dimensional coordinate measurement function is realized,and the standard spherical surface is measured in real time.