03 汽车防撞控制系统（03 automotive anti-collision control system）.doc

03 汽车防撞控制系统（03 automotive anti-collision control system） This article is contributed by xudong078 Ppt documents may experience poor browsing on the WAP side. It is recommended that you first select TXT, or download the source file to the local view. Vehicle anti-collision control system Current running state 1., high speed, 2. speed, 1. vehicles, 2. vehicles, 3. long highway, 3. long highway, 4. drivers mental pressure, 4. drivers mental pressure. Conclusion: the rate of rear end crash is high Requirements for automatic collision avoidance systems Requirements: 1., environmental monitoring 2. anti collision determination 3. vehicle control core two, anti-collision radar: Determination of the safety distance in the car; three, several major methods: ultrasonic ranging; laser ranging; radar ranging; System composition of collision module First, car ultrasonic, radar, reversing collision Taking advantage of the reflection characteristics of an ultrasonic wave the time difference between the emitted and received reflected waves T, S=CT/2:C is the sound velocity and is related to temperature (C is considered constant here); T is the time Low frequency modulation transmitting circuit Clock circuit, bistable circuit, accepting circuit Counter display circuit The relation between sonic speed and temperature Temperature -30, -20, -10 0 (DEG) 102030 Sonic 313319325332338344, 349 (m/s) The principle of ultrasonic sensors Structure of ultrasonic sensor Piezoelectric ceramic wafer Ultrasonic sensor detecting method A molding connector of the ultrasonic transducer. The two power lines; a double line (signal line) the working voltage: 12V; switching threshold is lower than 1.5V, the control unit sends the excitation signal sensor. The measuring range: 0.25 ~ 1.5m Nissan car ultrasonic radar reversing collision avoidance system Range adjustment radar Two 、 laser ranging anti-collision control system 1 、 laser warning device for preventing rear end collision The device structure com