Research On Vehicular Multi-objective Adaptive Cruise Control System Based On MPC Algorithm

As an important part of advanced driver assistance system,adaptive cruise control system(ACC),which can effectively reduce the operating intensity of drivers and improve the driving safety,has received extensive attention of automobile manufacturers and research institutions at home and abroad in recent years.Based on the hierarchical system architecture,the safe vehicle spacing distance mode,upper decision-making algorithm and lower control strategy of ACC system are designed in this thesis,and the model predictive control(MPC)algorithm is applied to take into account the performances of driving safety,car-following,passenger comfort and fuel economy in the process of driving.The multi-objective control method of adaptive cruise control system is studied.The main research contents of this thesis include:(1)Based on the hierarchical control scheme,the overall control scheme of ACC system is designed.The control algorithms of cruise control mode and following cruise control mode are studied,and the switching logic between the two modes is defined.At the same time,the safety distance model is designed.(2)The vehicle inverse longitudinal dynamics model,which can reflect the dynamic characteristics of the system,is built according to two kinds of working conditions of driving and braking,and the widely used switching strategy based on the threshold is adopted for the division of two kinds of working conditions.Then,on the basis of that,the feedforward and feedback control method used for the lower control strategy of ACC system is designed.(3)The upper decision-making algorithm of ACC system is designed based on MPC control method,the objective function and constraint conditions are established according to the optimization objectives of driving safety,car-following,passenger comfort and fuel economy,and finally converted to a quadratic programming problem with constraints.Meanwhile,a method of variable weight coefficient is designed based on the fuzzy control theory.(4)Based on the joint simulation platform of Simulink and Carsim,the simulation tests are conducted in five typical conditions including cruise control,following cruise control,cut-in and cut-out as well as emergency braking.The results show that the designed control algorithm has a good effect on all working conditions,and can take into account multiple control objectives in different scenarios.