Study On Estimating The State Of Driving Safety In True Environment And Rear-end Collision Warning System

This thesis has analyzed systematically the circumstances of road traffic safety and the current situation of the research on the safety technology of automobile all over the world. It has also made an analysis on the research, applications and the existing problems in active automobile safety technology fields, and pointed out the significance to estimate the state of driving safety in complicated environment and to study a suit of Rear-end Collision Warning and Auto-Breaking System.The theories of man-machine system and security assessment are applied synthetically in this thesis. Aiming at driving safety state, the paper sets up a complicated estimating index system from three basic elements of driving safety—person, vehicle, environmental effect; makes use of the way of analytical hierarchy process to establish weight modulus of various indexes and constructs a complete model to evaluate driving safety state with the method of wielding linearity weighted.According to the model of estimating safe running state on vehicle, a counting model of the safety distance between two cars on expressways in practical situation is studied and established. Based on this model, the design of the system of anti-collision and auto-breaking is presented: using laser radar to measure the distance of own car to frontal car, collecting the information of driving circumstances with several sensors, and analyzing and judging all of such information using a Single Chip Microcomputer of 8 bit MCS-51 series which is the controlling center of the system. When the following distance is less than the safety following distance, and there is a hidden trouble of rear-end collision accident, an alarm will ring to the driver until the auto-breaking is taken.The research in this paper can bring an effective way to decrease the occurrence of rear-end collision accidents on expressways and improve the traffic efficiency. It can also provide theoretical support and specific ways for the further research of this project.