Simulation Research On Auto Adaptive Cruise Control System

With the continuous development of China’s economy and the improvement of people’s living standards,the number of cars is increasing year by year,which brings convenience to people’s travel,but also brings some problems,such as the number of urban traffic accidents is increasing year by year,traffic congestion is becoming more and more serious.These are the problems that people are concerned about and urgently need to solve.The adaptive cruise system installed on the vehicle can actively control the throttle and brake,which can reduce the fatigue of the driver,thus reducing the probability of traffic accidents and reducing casualties and property losses.Therefore,it is necessary to study the adaptive cruise system.Firstly,on the basis of extensive literature review at home and abroad,the longitudinal dynamics model of the vehicle for adaptive cruise control is established in this paper,including engine model,hydraulic torque converter model,automatic transmission model,vehicle transmission,driving system and vehicle motion system model.At the same time,the actuator model and the safe distance model are established,and the distance model is compared and verified by simulation.Secondly,adaptive cruise control strategy is studied in this paper.Based on the fuzzy control theory,a fuzzy controller with speed difference and real-time vehicle distance difference as input and throttle opening and brake pressure as output is constructed,and its realization principle and method are analyzed in detail.Taking Matlab/Simulink as the platform,the control model of adaptive cruise control system is established,and the simulation verifies the rationality of the longitudinal dynamics model in various working conditions.Then,the longitudinal dynamics model of the vehicle is connected with the adaptive cruise controller,and the overall simulation model designed in this paper is constructed to realize the automatic control of throttle opening and brake pressure.Finally,Matlab/Simulink is used as the platform to simulate and analyze adaptive cruise control under different vehicle conditions.The speed change,distance change,accelerator pedal change and brake pressure change rules of ACC vehicles under uniform speed driving condition,deceleration driving condition,following driving condition,acceleration driving condition and mixed working condition were simulated respectively.Through the analysis of simulation results,it is proved that the ACC fuzzy control strategy proposed in this paper can reasonably control the vehicle under different working conditions,and the control accuracy is ideal.