Hardware-in-loop System’s Simulation Based On Vehicle Steering-by-Wire Platform

The vehicle Steering by Wire (SBW) system is seemed as the revolutionaryachievement of steering system and received more attention by a lot of researchconstructions and famous automotive manufacturers around the world. The defects ofdivisibility and stability which are caused by the mechanical connection in thetraditional steering system have been solved by SBW system. Because SBW systemlaunches the command of steering by the electronic signal and possesses the functionof motor drive to steering. Moreover, the humanization requirement of rational feelingfrom steering wheel feedback is satisfied by the SBW system. In this paper, therelevant problems of SBW system was analyzed and resolved via the simulationexperiments which were supported by the SBW system experiment platform.Firstly, the hardware platform was established by the components of SBWsystem. The transmission mechanism, the actuating mechanism and the experimentaltable were designed. And then the appropriative electromotors, sensors had beenchosen by the relevant state parameters which were measured by the SBW platformand vehicle model. In order to content with the requirement of data transmissionbetween the vehicle model and hardware platform, the simulation platform wasestablished that based on Carsim-RT. And the data of system was collected andcontrolled through the LabVIEW platform. The equipment of data collection and thecomputing unit was chosen by the communication protocol and computing speed,allowed the experiment to test the SBW system control algorithm.Secondly, the tire and the vehicle model were constructed through the systemdynamic equation. And the steering wheel and steering system model wereconstructed on the grounds of SBW system hardware. The steering ratio can beadjusted actively through the state estimation of vehicle driving, so the conditionswhich included the constant of yaw rate gain and the constant of lateral accelerationwere utilized as the prerequisite to eatable the ideal ratio model.Thirdly, an adaptive sliding mode controller is designed based on the theory ofsliding mode control. The controller input is defined as the weighted combination ofyaw rate and sideslip angle errors, and the desired front wheel angle is calculated asthe output. The simulation results show that the controller can improve the handlingstability and divisibility for SBW system.Finally, considering the difference between the SBW system and traditional steering system, in order to satisfy the driver’s need, the PID fuzzy controller wasapplied to adjust the torque of steering wheel when the feeling of steering wassimulated. And then through the analysis of ideal steering wheel torque the fuzzycontroller was established and confirmed by the SBW platform. The simulation resultsshow that the controller can improve the handling characteristic for SBW system andrealize the ideal steering for the driver.