Research On Short-range Auto Laser Anti-collision Radar

With the rapid improvement of living standards, auto has gradually become anessential transportation means in human life. However, when people enjoy in theconvenient transportation, people also pay a heavy price in life and property securityrespect. Therefore, in order to avoid or reduce the incidence of traffic accidents, the autolaser anti-collision radar emerged at the right moment. The study of this techniquestarted earlier in foreign countries, and it has been gaining popularity in the imports ofhigh-end cars. In comparison with abroad, domestic research on the laser anti-collisionradar had a rather late start. As a consequence, applying the mature technology in thedomestically made models will take a while. This paper aims at the research of autolaser anti-collision radar, quickening the pace of the technology applying in thedomestically made models. And then improve the overall automotive safetyperformance. Ultimately, achieve the goal of lower traffic accident rates.Based on the pulse laser ranging principle and the high precision time to digitalconversion chip named TDC-GP21which is made by ACAM, the paper aims atstudying auto laser anti-collision radar. And it can detect the distance, relative velocityand relative position between car and obstacles for close distance and low speed movingvehicles. The present paper propose the whole design schemes of auto laser anti-collision radar with orientation recognition, and have accomplished hardware andsoftware design, production of PCB and debugging for the various subsystems. Theconcrete content includes: laser emission and MOSFET driving circuit module, laserreceiver and its voltage bias circuit module, a weak signal conditioning module, highprecision time interval measurement module, overall system controlling and dataprocessing through the software programming, etc.Laser transmitter mainly provides light source in certain optical band for laserreceiver. For driving laser transmitter to lasing, design the MOSFET driving circuit.And the narrower the pulse which drives laser, the greater the transmission power ofsignal light. The feature is beneficial to improve the accuracy of laser ranging.Laser receiver circuit is designed for receiving the weak light signal which isthrough diffuse reflection, and then it converts the weak light signal into current signal.Make use of this kind of transform, to provide supports for follow-up signalconditioning circuit. Avalanche photodiode, also called APD, is chosen to be laserreceiver. Hence, high voltage bias circuit which match with the APD have to bedesigned to ensure APD can operate normally. Weak electrical signal conditioningcircuit module is used for the switch from current signal to voltage signal, and thenamplify the voltage signal to provide supports for the flight time measurement module. Finally, make use of the STC89C58to realize the overall control of the circuit,including: communication with the TDC-GP21, providing driving signal for lasertransmitter, serial communication with PC and the error compensation of test data, etc.