Research On The Short Distance High Accuracy Of Pulsed Laser Range Finder

Short distance measurement is widely used in the production and life, compared with laser phase-shift ranging, pulsed laser ranging has the advantages of system simple, large measurement range and fast speed, so the topic choose pulsed ranging as research content. In this thesis, the new short range high precision of pulsed laser range finder was researched and developed base on the pulsed laser ranging system's each core module by depth analysis and optimization. It is characterized by high-accuracy, easy to use and low cost.The paper had been done deep study of pulsed laser measuring system, mainly including the laser emitting circuit, the laser receiving module and the high-precision time measurement circuit. The narrow pulse generating circuit was designed using 74LS123 and LM555 integrated chip design in the emitting part, the pulse could be continuously adjustable in the frequency range of 0.5 kHz-1kHz and 10～500μs delays. In the receiving module analyzed and study for the signal of echo amplification, filtering, shaping and time identify circuits, cutting-edge moment discrimination circuits are designed to reduce the error of due to amplitude random jitter by comparison and selection the existing time discrimination circuit. Pulse time of flight measurement accuracy directly affects the whole measurement of the pulsed laser ranging system accuracy, so high-precision timing chip TDC-GP2 is used measurement pulsed time of flight in the high-precision timing circuits. It not only makes the circuit structure become simple but also improve accuracy. By taking these measures improved the accuracy of the conventional pulsed laser ranging system.