Research On Control Strategy Of Four-wheel Hub Motor Intelligent Car

In recent years,the world has faced serious problems of air pollution and energy security.Therefore,electric vehicles are increasingly attracting attention from companies,universities and research institutions around the world.The hub motor is a new type of electric vehicle driven by a hub motor,especially the four-wheel independent technology helps to improve the car's movement.The control system is one of the key systems for driving an electric car with a hub motor.This paper chooses to study the smart car control strategy of four-wheel hub motor.The main research contents are as follows:1)First,establish a dynamic model of 7 degrees of freedom,build a tire model,and build a DC motor model.Use this feature of Simulink to set up the car simulation model.Then,the simulation of the design parameters is verified.2)The control system is one of the important systems of the car.For the electronic differential,the speed is used,and the Ackermann model is used as the algorithm.The hub motor,controller uses a dual closed loop controller.Next,an electronic differential model and a brushless DC motor control model are established in Simulink.Link the model for simulation.The electronic differential and the electronic-free differential contrast simulation was carried out.The simulation results show that the car is more stable through the electronic differential,the turning radius is smaller,and the wheel slip is much smaller.Simultaneously perform vehicle performance simulation.3)Design from the simulation result parameters and according to the design requirements,working principle and control strategy.Convert from 3D models to 2D CAD drawings,sequential frame processing,drive system and steering system design and installation.According to the vehicle power,the hub motor,stepper motor and battery matching are selected.The host computer controls the 4-wheel drive motor and the steering motor through the Arduino controller.The angle sensor and the speed sensor are used to feedback the motor speed and steering angle in real time,and then assembled into a complete vehicle.4)This article uses Labview and Arduino to control and program on Labview software.Speed and control performance testing is tested by experiment.The experimental results show that the minimum turning radius is equal to 2.2 meters through the differential car,and the vehicle climbs the slope and reaches the maximum angle of 25 degrees.The experimental results are almost identical to the simulation results and meet the design requirements.