The Control Strategy Of The Rear-wheel Independent Driving Electric Formula Racing Car

The Formula Student China(FSC)originated from the Formula SAE(FSAE)in the United States.It is based on the mechanical,electrical and other courses learned by students in daily life,and aimed at cultivating automobile talents and increasing their practical experience.In order to adapt to the development of new energy industry and the rise of electric vehicles,the Formula Student electric China(FSEC)was officially held in 2013.As the core of a racing car,the control strategy of the whole car has a direct impact on the race results.Therefore,the research on the control strategy of the whole car is of great importance.In this paper,the rear-wheel independently driven electric formula racing car,the racing vehicle of north China university of technology in 2018,is taken as the research object to conduct relevant research on its vehicle control strategy.Firstly,this paper adopts Carsim software for vehicle modeling and verifies the rationality of its equation vehicle design through basic simulation.Secondly,the rear-wheel independent drive vehicle control scheme is analyzed,which can be divided into three aspects:Traction Control System,Electronic Differential System and Braking Energy Recovery System.The traction control strategy is adopted in the Traction Control System,and the slip ratio is controlled within a reasonable range by combining with pavement identification.The feed-forward control is adopted in the electronic differential control strategy to reasonably allocate the torque of left and right wheels,and the electronic stability control strategy is adopted to modify the feed-forward control by introducing yaw velocity as feedback quantity,so as to ensure the stability of the vehicle in emergencies.To simplify the algorithm,this paper proposes a torque differential control strategy based on yaw Angle,which is directly introduced into the control as a control quantity.Through the analysis of three common control strategies of electric vehicles,the Braking Energy Recovery control strategy can guarantee that the vehicle will convert its kinetic energy into electrical energy to achieve the purpose of energy saving when braking.Then,by using the joint simulation of Matlab and Carsim,the reliability of its three-direction control strategy is verified.Finally,the vehicle electronic control system of the formula car is constructed,and the safety circuit is designed and analyzed from the perspective of safety to ensure the safety of the driver,and the detection and protection circuit is described.The feasibility of the vehicle control strategy was verified by the no-load experiment.The stability of the vehicle control strategy was verified by the running test of the two drivers.And the energy recovery was basically consistent with the expectation by comparing the energy consumption.