Study On The Portable Pulse Laser Range Detection System

With the development of laser technology,Laser ranging becomes a new precise measurement technology,and is extensively used in the military and civil field for its high accuracy.The laser range finder is divided into pulse and phase two types at present.The phase measurement technology is mature with high precision and is adopted mostly nowadays,but the phase range-measuring circuit is complex and hard to realize.Pulse Laser Range Finder(PLRF) has many advantages,such as compactness,facilities of signal process,the real-time measurement and huge development potential.For limit of the time measurement precision,this method is not suitable for the short range and high accuracy measurement system.This paper introduced a laser ranging system and mainly discussed the solutions to the key problem of short time interval measurement with high precision.High integration and advanced time-to-digital chip(TDC)measurement system scheme was employed,and on the basis of analyzing the performance of LD,the pulse constant current supply was designed in this paper. Besides,an effective design scheme of the reverse bias voltage and temperature compensating circuit was proposed based on the comprehensive analyses of the performance of APD,the design of time measurement cell via MCU was presented.Theoretically,the simulation testing showed that the measuring range is 0.5-270m.Lots of researches have done as follow:(1)On the basis of comparing the existing laser ranging technology,and studying the theory and design method of the time-of-flight(TOF)measurement,a TDC pulse range measuring system is proposed.(2)On the basis of analyzing the performance of LD,the pulse constant current supply is designed to make sure that the LD can produce the qualified pulse laser.(3)In the system high speed PD and APD are used for transferring the pulse laser to weak electrical current.A design of the bias voltage and temperature control system circuit is proposed on the basis of analyzing the performance of APD.The voltage stability adapt to the APD.(4)By through study the theory and design method of the TOF measurement,the time measurement cell based on the chip of ADμC812 and TDC-GP2 is designed and it can improvement the precision of time measurement is low in PLRF.