Research On Full Speed Adaptive Cruise Control System Of Pure Electric Vehicle

With the promotion of energy saving and environmental protection and the rise of intelligent upsurge,the development of advanced driver assistance system for electric vehicle has been paid more and more attention.At present,the adaptive cruise of electric vehicles has many impact places that work speed is limited,tracking and anti-interference ability is poor,and it can not fully adapt to the complex and changeable driving environment.Therefore,it is of great significance to study the response of adaptive cruise control system on full speed and external disturbance conditions.This paper studies the switching and execution strategies of pure electric vehicle ACC on different working modes.The longitudinal control method based on quadratic optimization and model predictive control theory are used to simulate on the different driving conditions,and the effectiveness of the control strategy and algorithm is verified.This paper selects vehicle speed as the controlled object,and the longitudinal dynamic model and the three-phase AC induction motor model are established respectively.The direct torque control method is used to realize the rapid tracking of the desired speed and torque.In order to obtain the reference trajectory of the driving distance,a driving distance strategy based on the variable distance and the emergency braking safety distance theory is proposed.The simulation analysis for different spacing strategies verifies that the spacing strategy considering the road utilization and safety has stronger flexibility,and is more suitable for multi-road driving environment.In this paper,the three cases of function switching,driving and braking control and active intervention are analyzed and processed.The switching and intervention control strategies based on threshold logic judgment,and the power output control strategy considering the mechanical and regenerative braking torque distribution are established.The adaptive cruise control system based on adaptive fuzzy PID and model predictive control algorithm is studied.The simulation and comparison of MATLAB / Simulink on cruise conditions are carried out on the two control algorithms.The simulation results show that compared with adaptive fuzzy PID control,the model predictive control reduces adjustment time by 46.7%,the overshoot of the speed adjustment by 87.5% and the overshoot of the acceleration adjustment by 100%.The simulation results of model prediction control show that the model predictive control can meet the control requirements of full-speed range,and guarantee the global performance of the system on different following working conditions.The advantage of model predictive control in the case of multi-variable and multi-constrained complex control system is obvious.In order to further verify and explain the effect of control,the pedal opening and torque changes during the driving process are simulated by MATLAB / Simulink and Carsim.The validity of the adaptive cruise control strategy and algorithm is verified,which can effectively control the longitudinal Driving.