Research On Design And Simulation Analysis Of Vehicle Adaptive Cruise Control System

Vehicle adaptive cruise control system(ACC)is an advanced assistant driving system(ADAS)developed on the traditional cruise system.The core function of ACC system is to control the movement of the vehicle according to the motion state of the front vehicle.When the vehicle,pedestrians or obstacles of the front vehicle affect the running state of the vehicle,ACC system will control the vehicle to maintain a safe driving distance.When the moving state of vehicles,pedestrians or obstacles of the front vehicle has no influence or danger on the moving state of the vehicle,the function of constant speed driving can be realized.The main research contents of this paper include:(1)CarSim software was used to build the longitudinal dynamics model of the vehicle,and the vehicle braking/drive switching strategy was designed to prevent frequent switching between braking and driving during vehicle movement.The lower layer controller of vehicle ACC system,which includes the inverse longitudinal dynamics model of vehicle drive system and braking system,is designed,and the simulation model of the lower layer controller of vehicle ACC system is built in matlab/Simulink environment.(2)In the calculation of the vehicle safety distance,the variable headway safety distance model and the variable headway safety distance model considering the acceleration of the front vehicle are adopted,and the safety,follow-up and comfort of the vehicle during driving are considered.The two safety clearance models were simulated and analyzed in five typical pavement conditions of ACC system.(3)Classical PID control algorithm,single neuron neural network PID control algorithm and RBF neural network PID control algorithm are used to design the upper controller of the vehicle ACC system distance control mode.And under five typical working conditions,the vehicle ACC system distance control mode using three control algorithms was simulated,and the simulation results were carried out from the perspectives of vehicle safety,car following,comfort and economy comparative analysis.(4)The classic PID control algorithm and fuzzy adaptive PID control algorithm are used to design the upper controller of the vehicle ACC system constant speed mode.And under the typical working conditions of the three vehicle ACC system constant speed modes,the designed vehicle ACC system constant speed mode is simulated separately,and the simulation results are compared and analyzed from the perspective of system response speed and stability.(5)A switching strategy between the vehicle ACC system spacing control mode and the fixed speed mode is designed.In four typical operating modes of the mode switching,the safety,comfort and economy of the vehicle when the vehicle ACC system is switched between modes.This paper analyzes and compares the designed mode switching strategies.