Research On The Short Distance And High Accuracy Pulsed Laser Finder

Compared with laser phase-shift ranging,pulsed laser ranging which is system simple,far measurement range and fast speed,in addition, near measurement by widely used in the production and life, so the topic choose pulsed ranging as research content. In this thesis, we research and development a new short range and high precision pulsed laser finder based on the pulsed laser ranging system's each core module by depth analysis and circuit optimization. It is characterized by relatively high-accuracy, easy to use, low cost and on eye safety.This paper does deep study of pulsed laser measuring system, mainly including the laser emitting circuit, the laser receiving circuit, the high-precision time measurement circuit. The pulse circuit was designed using 74LS123 and LM555 integrated chip design in the emitting part, the pulse can be r continuously adjustable in the frequency range of 0.5 kHz-1 kHz and 10-500μs delays. In the receiver circuit analyzed and study for the signal of receiving amplification, filtering, shaping and time identify and made some improvements on the circuit, Constant fraction and peak discrimination circuits are designed to solve the problem of low precision existing in the pulsed laser ranging system comparing to the traditional time discrimination circuit, pulse time of flight measurement accuracy directly affects the overall measurement of the pulsed ranging system accuracy, so high-precision measurement of the timing chip TDC-GP2 is used in precision timing circuits, it not only makes the circuit structure become simple but also improve accuracy. Within 300 meters, the system of measurement error can be reduced to centimeter level by optimize the pulsed laser ranging system of each important circuit, to improve the precision in the measurements of pulsed laser ranging.