Research On Control Method Of Automobile Active Collision Avoidance Control System

In recent years,with the development of information science and technology,the active safety equipment has become a hotspot in research of active safety at home and abroad.Active collision avoidance control system as the initiative safety equipment,its development and the core is the control method.This paper focuses on analyzing and design active collision avoidance control method in vehicle longitudinal control system,including the safety distance model,control strategy of collision avoidance,vehicle dynamics system modeling and up-down controller design and so on.The main content of the research are as follows:(1)The safety distance model is the basis of active collision avoidance control system.After reading and analysis a large number of related literature which belong home or abroad,analyzing and comparing the three kinds of classical safety distance model,this paper determined the safety distance model mainly based on the threshold speed dividing safety distance model into high speed and low speed.In high speed,the active collision avoidance control system using the based on the braking process safety distance model.And in lower speed,the safety distance model chooses the based on headway safety distance model.(2)Designed collision avoidance control strategy based on the new model of the safe distance and the danger coefficient.The danger coefficient are introduced to determine the safety status of the vehicle.In generally,people would set the driver reaction time and road adhesion coefficient a fixed value in a certain range in safety distance model.In this paper,in order to improve the precision of the safety distance model,the safety distance model based on fuzzy mathematics theory is introduced into the determine method of driver reaction time and the identification model of tire-road friction coefficient.(3)Each component and the key parameters of the system were analyzed and modeled.On the basis of the principle of vehicle dynamics and automatic control of vehicle dynamics,seting the safety distance model?the driver reaction time model and the up-down controller model.(4)Design the collision avoidance control system function.Firstly the adaptive cruise control system is designed to reduce driver fatigue strength.In low speed condition,adaptive cruise control system can satisfy the movement which two cars keep the space driving,but if the ahead vehicle emergency braking condition,the application of this control algorithm can't completely avoid collision.So in this paper,aiming at the condition of the ahead vehicle emergency braking,studying on the safety distance model?collision avoidance control strategy and up-down controller to design collision avoidance control system.(5)The typical working condition is adopted to check the control method of collision avoidance system.In CarSim and Simulink to build the simulation model,for dry asphalt pavement?wet asphalt pavement?snow road and the working condition of high speed,verified the validity of the control method for collision avoidance control system.And analyzed and comprised the traditional braking process and the headway safety distance model designing the collision avoidance control system to validate the superiority of collision avoidance system control method in this paper.The simulation experiment results show that the design of the vehicle longitudinal active collision avoidance control method,for dry asphalt pavement?wet asphalt pavement ?snow road and the working condition of high speed,having a good control effect and achieving the function of emergency collision avoidance.At the same time,contrasted with the braking process and the headway safety distance model designed the collision avoidance control system,in this paper's collision avoidance control method in addition to help to improve the utilization rate of road traffic,also can better control the vehicle avoidance time and the distance of two cars.Designing the vehicle longitudinal active collision avoidance system provides a new way of thinking,also for the subsequent research laid a theoretical foundation.