Research On Technology Of High Precision Laser Ranging Signal Processing

Laser range finder is widely used in the field of measurement technology because of its high precision and long distance.At present,with the increasing demand for the distance measurement,such as civil,scientific research,military and other fields,how to obtain higher measurement accuracy under the premise of ensuring the measurement distance has become a hot research.At present,the method of pulse laser ranging which has the advantages of high measuring speed,wide measuring range and low precision is widely used in medium and long distance measurement.In the short distance measurement,the method of phase laser range measurement is adopted with the high measuring precision,low measuring efficiency and small range.Therefore,this thesis will carry on the concrete research and the related experiment on the two angles of the laser ranging precision and the extended phase laser ranging.First of all,the principle analysis,theoretical calculation,precision analysis and Experimental Research on the signal processing system of high precision pulse laser range finder are carried out.The key technologies,system construction and error analysis are analyzed.The design methods of time discrimination and time interval measurement are summarized,and the selection of the device,the structure of the circuit,and the precision analysis are completed.In this thesis,the experiment of the signal processing module of the pulse method.The two groups of signals are sent by the signal generator,and the time interval is measured.The error is analyzed by comparing the measured data.It can be found that the clock resolution of delay line interpolation is affected by temperature and voltage.Therefore,the time interval data of 200 ns are measured at time intervals,and the standard deviation of the time difference measurement is 180 ps.Which means that the measurement distance of 30 m,the measurement error of 2.7cm,to achieve a higher measurement accuracy.For the measurement distance of 30 m to 1.5km,the average measurement error is 3.1cm.On the basis of obtaining the high precision pulse laser ranging method,this thesis also presents a new method of pulse and phase.At the transmitter,the combined wave of the square wave and sine wave amplitude modulation simultaneously carries the flight time information and phase information.In the signal processing stage to pulse detection results as coarse scale ranging,phase ranging as a result of fine scale ranging,which makes the measurement of the composite ranging system has the advantages of accuracy and high phase method can realize long distance.In this thesis,the principle and theoretical calculation and precision analysis of the pulse and phase components are discussed.It is proved that the precision of pulse ranging can meet the requirements of the ranging system,and the design of the ranging system is completed.