The Design And Implementation Of A Vehicle Active Safety Pre-warning System

The development of transportation industry in our country is promoted by the acceleration of highway construction and the rapid growth of the car ownership, at the meantime, a lot of traffic accidents are caused and many casualties and huge economic losses are brought. Therefore it is very important how to apply the prevention measures about security early warning technology adhering to the "science and technology make security, public safety"idea to effectively reduce auto accidents in current times cars have being become very popular. Right now, the attention of the domestic and overseas scholars has been drawn to the research on the vehicle active safety system. With the comprehensive analysis of a large number of traffic accidents, the accidents are mainly consisted of crash, scratch, pendant and flat tire. But the accidents caused by collision and flat tire account for85%of the all traffic accidents, so the studies on the tire pressure detection and the rear-end collision warning of the paper is of great significance.The main research contents and academic achievements of the paper are as follows:(1) The overall design of the car active safety system, including function design and structure design, is completed. The chief functions of the system cover tire pressure detection and the rear-end collision warning, and the system structure is divided into tire pressure detection module and the central information processing system. The tire parameters, such as the tire pressure, are monitored by the tire pressure detection module, at the same time, the tire’s malfunction alarm and the rear-end collision danger alarm are completed by the central information processing system.(2) The design of the tire pressure detection has been realized from hardware and software. With depending on the degree of actual parameters, such as the inflation pressure, temperature and acceleration etc, deviate from the normal, the abnormal tire pressure warning is implemented. In addition the service life of the module is increased through the solved key technology of the low power design.(3) The mathematical module of the rear-end collision danger alarm has been established, and the algorithm of the mathematical module has been given. The traditional ranging method is fundamentally got rid in algorithm. The dangerous degree is predicted in the current driving environment, based on meta-analyses of the relative velocity, acceleration and relative distance which are got from GPS and transferred from vehicle to vehicle by ZigBee.(4) The central information processing system realizes sharing the car’s information of tire pressure detection parameters and the running slate received by the embedded micro-controller processor. The central system achieve communication among vehicles which includes the speed, acceleration, course, positioning coordinates, lane changing of cars, Therefore, hardware resource is saved, and the cost and complexity of the system is reduced.(5) The software design, which includes the tire pressure detection software, the central processing unit software and the other, is finished,(6) The simulation of the rear-end collision module is realized by software and the collision pre-warning is still effectively completed under the extreme conditions. The correctness of the data transmission among the key modules is confirmed by the module performance tests completed. The requirements of automobile active safety pre-warning system are met by the system.The automobile active safety system, the paper designs, has some innovations, such as low power, the single unclosed loop antenna, the information of driving parameter sharing among cars and the safety distance in the rear-end collision warning module between two vehicles. The system can increase the driver’s perception and effective help drivers to reduce traffic accidents.