Shape Center Timing And Time Measurement Technology Of Pulsed Laser Radar Echo Signals

With the development of electronics technology and laser technology,lidar has been rapidly developed and widely used.Today,lidar has been used in various fields such as the military,scientific research,and enterprises.In recent years,with the rise of drones,robots,and traffic safety,lidar has shown broad application prospects.The most basic function of lidar is ranging,and the key factor that affects the accuracy of ranging is the accuracy of flight time.The measurement of flight time requires accurate timing.The traditional time identification method will be affected by noise,rising edges,pulse width and other factors the effect of measurement results in a large measurement error,which affects the measurement accuracy of time.Thanks to the rapid development of high-speed AD technology,lidar full-wave echo signal detection has attracted attention due to its ability to obtain the overall data of the echo waveform.Among them,the waveform centroid method is widely used.This algorithm can use multi-point information to fully Considering the echo shape,the theoretical accuracy is higher.This paper proposes a laser pulse centroid timing algorithm based on slope selection and intensity weighting.This algorithm can adaptively select the waveform data that meets the requirements by calculating the slope,combined with the intensityweighted centroid timing algorithm to calculate the centroid of the lidar echo waveform.The characteristics of the laser pulse echo are analyzed,and the target echo broadening and distortion caused by the target surface slope,active area and reflectance are discussed.Several typical target echo waveforms are given.After analyzing the echo characteristics,an empirical model of short-pulse lidar emission signals and echo signals was established,the parameters required for the simulation were set,and the echo pulses were filtered.After this method and several common Lidar echo pulse timing methods are compared under different SNR simulations.Simulation results show that compared with other algorithms,the algorithm proposed in this paper has better calculation accuracy and stability,can effectively deal with clutter interference,and has stronger robustness.Finally,the error caused by the total time is discussed through the algorithm in this paper.The timing error caused by the signal-to-noise ratio and distance,the time measurement error caused by the sampling rate and quantization accuracy of the ADC,and the cumulative error caused by the clock are carried out under different conditions.Simulation and analysis.