Research Of Vehicle Multi-Mode Adaptive Cruise Control System Based On Multi-Objective

With the development of automobile intelligence,Intelligent Driving Assistance System is popular.According to statistics,90% of the traffic accident is caused by the driver's improper operation and fatigue driving.Adaptive Cruise Control(ACC)system as an important branch of longitudinal control of Intelligent Driving Assistance System,can effectively reduce the driving burden of drivers and traffic accidents caused by human factors.Due to the complexity of the driving environment,the fixed parameters of the traditional single control mode cannot identify different driving environments online,and it is difficult to consider different performance indexes under different driving environments.Therefore,the multi-mode ACC system in this paper is studied.Firstly,the overall scheme of the system is designed based on the idea of hierarchical control,and the priority strategy of driver active intervention was determined.The main control algorithm of the system was determined by analyzing the target requirements of the upper and lower controllersSecond,for the lower controller.The throttle/brake switching strategy is realized based on the method of setting buffer zone.For the strong nonlinear characteristic of the actuator system,the feed-forward and adrc technology is applied to the design of the acceleration and braking actuators of the system.Compared with the traditional PID controller,the simulation results show that the adrc has strong anti-jamming ability.For the upper controller,In order to enhance the ACC vehicle's ability to judge and adapt to the motion state of the front vehicle,the ACC system is divided into six working modes: cruise control,approach to the front vehicle,steady-state follow,deceleration approach,strong deceleration and emergency braking,the switching strategy based on the principle of hybrid automata is designed in view of the obvious hybrid characteristic of the system.For the control algorithm of the mode,the cruise control mode considering the road environment factors comprehensively is realized by using the PID control principle.The following system was realized based on the model prediction principle,the control objectives of safety,dynamic tracking,ride comfort and fuel economy were comprehensively considered,and a relaxation vector was introduced to the system constraints to ensure the existence of feasible rolling optimization solutions.By adjusting the system constraint parameters under the quadratic programming optimization solution,the division of five working modes in the following system is realized.The following weight adjustment mechanism is designed in order to realize the online adjustment of the following weight in the model predictive control in the process of following the vehicles.Then,the prototype of control strategy is built in Simulink module,the vehicle dynamics model is built based on CarSim software,and the offline joint simulation platform was built.Then,the simulation results of the multi-mode upper controller in this paper is compared with the ordinary controller in a single mode.Secondly,the simulation results of the overall control strategy of ACC are analyzed under typical working conditions,the results show that the proposed control strategy is effective and robust.Finally,a real vehicle platform is built based on the modified test vehicle,the following driving condition is selected to carry out real vehicle verification for the upper controller of the system,the results show the accuracy of the upper control strategy.