Research On Economical Adaptive Cruise Control Strategy For Electric Vehicles

To address the worldwide energy shortage and concerns over traffic safety,various countries and car manufacturers are adopting the trend of producing intelligent and electric vehicles,and intensive research is underway on support technologies.ACC system can recognize the vehicle ahead and keep the following cruise within a safe distance on the basis of constant speed cruise.While the development and research of this system has gained significant attention,there is currently a lack of research on its application in pure electric vehicles,additionally,the control strategy utilized by conventional fuel vehicles poses difficulties in being directly implemented.Therefore,it is highly significant to research the utilization of ACC system in solely electric vehicles.This paper will study the adaptive cruise system of pure electric vehicles,and propose a control strategy of eco-ACC system based on MPC theory.The major components are:(1)A control architecture for the adaptive cruise system is developed using the hierarchical theory;For the system operation mode,two modes of operation for the system are identified.And the strategy can automatically switch the vehicle control mode under specific conditions,enabling the vehicle to better adapt to specific road and traffic conditions under different driving conditions.It also proposed to facilitate the transition between these two modes.To account for electric vehicles,an analysis of pure electric vehicles is conducted and a vehicle model is developed based on their specific characteristics.(2)A longitudinal inverse dynamic model has been established in this article.Including the brake force model and the driving force model;Design drive/brake switching strategy to prevent the system from switching control mode frequently during the control process;A lower controller based on PID algorithm which is to compute the appropriate torque for either driving or braking of a given vehicle,and adjust the acceleration of the vehicle by controlling the driving torque or braking pressure of the vehicle to achieve stable following of the expected acceleration of the vehicle.(3)Based on the fixed headway algorithm,the safety headway model and the longitudinal car-following kinematics model of the workshop are established.On this basis,the ACC upper controller based on the MPC algorithm is established,and the control requirements are analyzed and the objective function is established;The linear combination weighting method based on entropy is used to determine the weight coefficients of the following,economic and comfort indicators,and the performance indicators.In the last resort,it is converted into a quadratic programming problem.(4)Built an ACC vehicle hardware in the loop experimental platform for simulation and analysis of control strategies,four typical road conditions are designed for different conditions in the car-following process to test the control strategy.The results demonstrate that the strategy proffered in this article get good performance in control process.