The traditional pulse laser ranging system based on the measurement of time of flight often ignores the nonlinear influence of the intensity of the echo light power on the range error of the receiver system. Based on the transistor model (Gummel-Poon model), this paper makes a systematic modeling of the pulsed laser range finding receiver system. By means of computer aided analysis, the relationship between the input current waveform and the leading edge of the response pulse of the receiving system is analyzed. And thus, the relationship model of the echo light power and front of response echo pulse is derived in the paper. Based on the above model and by involving the method of differential threshold time discrimination, the walking error in the laser ranging system is corrected. Finally, the experimental results show that this method can effectively correct the nonlinear error caused by the fluctuation of the echo power and improve the accuracy of the ranging system.
This paper first introduces the basic principle of the four quadrant detector, and a set of laser positioning experiment system is built based on the four quadrant detector. Four quadrant laser positioning system in the actual application, not only exist interference of background light and detector dark current noise, and the influence of random noise, system stability, spot equivalent error can’t be ignored, so it is very important to system calibration and correction. This paper analyzes the various factors of system positioning error, and then propose an algorithm for correcting the system error, the results of simulation and experiment show that the modified algorithm can improve the effect of system error on positioning and improve the positioning accuracy.