The Hardware And Software Design Of Phase Laser Ranging System Based On "double Sending And Single Receiving" Mode

The Laser ranging is one of the core technologies of current smart devices.With the continuous advancement of technology and industrial informationization,it is becoming a key technical bottleneck restricting the development of fields such as map mapping,automatic driving,and robot positioning.To further improve the ranging accuracy,optimize the circuit structure,and reduce the design difficulty and design cost,this subject has developed a highprecision and low-cost laser ranging system which is based on the the "double sending and single receiving " detection mode.The main research includes as follows:(1)Designed a dual-optical path detection technology scheme based on the "double sending and single receiving" mode,established a mathematical model between the distance to be measured and the phase difference in this mode,and given the principles of multiple measuring rulers selection and measuring rulers Fusion method.(2)Completed the design of the corresponding circuit module,including high-frequency signal generation circuit(maximum output 200 MHz),LC resonance frequency selection circuit,APD drive power supply(adjustable range 22 V ? 178 V,maximum ripple 15.6 m V),MFB filtering Circuits and so on.The design method of low-noise transimpedance amplifier circuit based on T-network is given.The relationship between noise gain and the stability of TIA circuit and its corresponding stability compensation measures are analyzed.It is proposed to improve the sampling rate of ADC to simplify Filter design method.(3)The software control program of the upper computer is written,including the spectrum analysis based on all-phase FFT,the sampling program of ADC time-sharing in the " double sending and single receiving " mode,and the control program of each module.The phase measurement accuracy of FFT and all-phase FFT at different sampling rates and different sampling points are compared.The phase measurement performance of ApFFT is simulated and tested under different SNR.Introducing the method of the second homologous reference signal to realize the phase difference measurement between the two time-shared sampling signals can effectively reduce the sampling error and improve the phase measurement accuracy.(4)Complete the overall PCB drawing and circuit test of the system,and analyze the measurement results and error factors.The experimental results show that the highest ranging accuracy of the system can reach ± 2mm.