Research On The Returnability Of Steering System

The steering performance of a car is good or bad can be evaluated with a lot of characteristic parameters,Where in the returnability is one of them,which plays a vital role in the vehicle safety and handing stability.This article is based on the mechanism of mechanical steering system aligning torque generated as the research base,and then to take an Electric Power Steering System(EPS)as the research object and study its power characteristics under different conditions,and finally to establish return-to-center control model that meets the operational requirements of the driver.(1)Three typical models are chosen to compare on the basis of aligning torque at home and abroad.According to the simulation results to find a method to choose the aligning torque foundation model of EPS.(2)The EPS working principle and classification are described.And a foreign-type electric power steering system structure torque sensors,motors and accessories of the composition,functions and features are discussed,and the circuit diagram of the electric power steering system is drawn,then based on the circuit diagram to build the steering system test bench.(3)The test bench is used to do the assist characteristics test,and the motor assist characteristic curve is got at different speeds and different steering wheel torques.And based on these curves to find a mathematical model of motor torque changing with speed and steering wheel torque(4)Aligning torque model and motor mathematical model are used to establish the assist control model of EPS,and based on the aligning torque equilibrium equation to establish return-to-center control model of EPS.The return-to-center control model for joint simulation to get steering return-to-center characteristic curve which verifies the validity of established return-to-center control model.