Test And Simulation Research Of Four Wheel Steering Sample Vehicle Driven By Hub Motors

The vehicle driven by hub motor has great potential in power control,spatial layout,energy saving and body state observation,which is an important development direction of electric vehicles.Safety is the primary performance requirement of vehicles.The research on the motion law of vehicles on special roads such as curves and ramps has guiding significance for vehicle safety control.Therefore,this paper mainly carried out the following research work:(1)The performance test and output torque fusion estimation model of hub motor are established: the test platform of hub motor is built,the measurement and control software based on LabVIEW is developed,and the quasi-static performance tests of four hub motors used in the sample vehicle test are carried out.In order to obtain the moment of inertia of the hub motor,a method of measuring the moment of inertia of the hub motor with "acceleration drag method" is proposed.According to the test data of each motor under the quasi-static condition,the neural network estimation model of the quasi-static output torque of each motor is trained.On this basis,the dynamic model of the hub motor is combined,and the fusion estimation model of the output torque of the hub motor is established It is verified by experiments;(2)The establishment of the joint simulation model of the whole vehicle: Based on the force analysis of the rolling motion of the vehicle on the ramp,the ramp resistance fluctuation model is derived.On this basis,the combined simulation model of 4WID/4WS sample vehicle is established by using CarSim and MATLAB/Simulink;(3)Ramp rotation test and simulation analysis of the test vehicle: the steady-state rotation test of the vehicle is carried out by using 4WID/4WS electric vehicle developed in the laboratory.The test results show that the dynamic parameters of the vehicle fluctuate obviously.In order to solve this problem,the simulation model is used to carry out the simulation study,and the analysis shows that the fluctuation of ramp resistance and vehicle inertia force are the main factors that cause the fluctuation of vehicle dynamics parameters.In addition,the deviation between the front wheel angle of the simulation model and the actual angle also causes some errors.On this basis,the influence of slope and centrifugal force on vehicle stability is simulated.