Research On Key Technology Of Multi-pulse Accumulative Ranging Based On Zynq

Pulsed laser ranging is currently widely used,and can be used in environmental detection,satellite observation,unmanned driving,agriculture and forestry,etc.,and the anti-interference ability in the ranging process is very important.Poor weather conditions and complex environmental interference can easily cause false alarms and missed detections.In order to better improve the measurement accuracy,on the basis of not increasing the difficulty of hardware circuit design,this paper adopts the method of digital signal processing to improve the signal-to-noise ratio of the laser pulse echo signal.By adopting the multi-pulse dynamic accumulation algorithm and the wavelet threshold denoising algorithm,the anti-interference ability of the ranging system is enhanced,the quality of the echo signal is optimized,and the measurement accuracy is improved.This subject first studied the basic principles of laser ranging,analyzed the laser ranging equation and different types of errors,and calculated the signal-to-noise ratio required to meet the detection probability.The multi-pulse accumulation technology is emphatically studied,and the effectiveness of the method is verified through theoretical derivation and simulation.An improvement is proposed to solve the problem that the accumulation times are difficult to determine.The specific accumulation times are dynamically adjusted by measuring the signal-to-noise ratio of the initial echo,which is more adaptive than the fixed accumulation times.Secondly,the accumulated signal is subjected to secondary processing by wavelet threshold denoising,and db3 is selected as the wavelet basis function to decompose the signal in three layers,the threshold of each layer is dynamically set and the appropriate threshold function is selected to further remove the noise,which can be more accurate Determine the specific location of the echo pulse.In order to further improve the measurement accuracy,the multi-clock phase shift method is used,and the phase-locked loop is used to generate 8 45° phase-shifted 200M clocks with the same frequency.The time measurement resolution can reach 300ps,and the threshold is set at the half-width of the pulse signal The judgment ends the single ranging,and the error caused by the change of the signal amplitude is reduced.The Zynq development board is used to build the experimental platform transplant algorithm,and the ranging experiment is analyzed.The ranging result is transmitted to the DDR on the PS side through the DMA channel,which verifies the effectiveness of the digital processing algorithm proposed in this article and effectively improves the laser ranging system Detection ability and accuracy for low signal-to-noise ratio signals.