Simulation of Effect of Online Steering Ratio Calculating and Adjusting on Steering by Wire System 2019-01-0512
This paper aims to test the effects of variable transmission ratio on the steering performance of steering by wire(SBW) system with the method of Carsim and Simulink co-simulation. Firstly, an SBW model is built with components of the simscape library in Simulink, which consists of the online variable transmission ratio calculation model, the electric drive steering feel model, steering gear model and their PID control model. Then, this model is used to replace the steering system of Carsim vehicle model to achieve a new SBW vehicle model. Finally, the performance of this vehicle is simulated in double lane steering condition by setting the state of steering gear ratio into fixed value or online adjusting. The results indicate that the discrete control with the online steering ratio calculating and adjusting can reduce the lateral acceleration of the vehicle at the cost of the increase of the ascending of lateral displacement error.