Algorithm Analysis And Simulation Of Electric Power Steering

In recent years,Electric Power Steering System(EPS)is developing faster and faster.Its market and application prospect are also more widely,and it has become a hot issue of car's steering technology research in modern society.EPS is saving and environmentally friendly.More and more,it can resolve the conflicts between "light" and "spirit" in car's steering technology better than mechanical steering system and hydraulic steering system.So,it is good for improving the car's driving safety and handling stability.The research status of EPS at home and abroad was studied through reading a large number of references.In order to analysis the EPS better,its structure and working principle was studied and its dynamic equation was built.The multi-body dynamics model of a vehicle was built by ADAMS/car.Then it's handling and stability was verified through suitable system parameters.According to the need to select and determine the use of characteristic curve,namely linear dynamical characteristics curve.The control simulation model of EPS was built through Matlab/Simulink.The assist characteristic curve model,motor model and PID control models were included in the model.The target current value was chosen according to torque and speed based on the assist characteristic curve model.Then the error between target current value and actual current value was tracked.The error was adjusted in real time,so that the ideal power torque can be exported by power motor.The best steering can also be obtained at the same time.The traditional PID control method and fuzzy PID control method were chosen in simulation analysis.The typical operating conditions such as low back positive,serpentine crossing and angular pulse were studied in simulation experiment.The experiment shows that the vehicle which is equipped with EPS is of good handling stability and driving safety.The EPS not only make the vehicle turn light but also improve the turning performance.Both traditional PID and fuzzy PID can achieve a good control effect in control process.But more can highlight the real-time fuzzy PID adjustment,better adaptability.