Research On Road Feel Simulation And Steering Ratio Characteristics For Steer-by-wire System

The structure and control mode of automobile have been changed by X-by-wire,which promote the integration,lightweighting,networking and intelligence of automobile greatly.Steer-by-wire system is a new type of steering system appears after the electronic power steering system.It breaks the shackles of mechanical structure of the conventional steering system,and more energy-efficient,environmentally-friendly and efficient,which is consistent with the demands of ‘Made in China 2025' times development.Therefore,research and development of steer-by-wire system will have great theoretical significance and value in engineering application.This paper has launched some research which mainly focuses on the issue that road feel needs to be simulated in steer-by-wire system.Firstly,the structure and working principle of steer-by-wire system are introduced.Establishing the whole vehicle model and the steer-by-wire system dynamics model through CarSim software and MATLAB/Simulink software,which lays a foundation for researching the control strategy and simulation analysis following.Secondly,this paper studies the control strategy of road feel simulation.Proposing a steering effort model bases on analyzing the influence factors of steering effort characteristics.And then doing parameter identification of the model using the test data of driver's preferred steering effort.The single neuron self-adaptive PID algorithm is adopted to control the road feel motor,and verifying the effectiveness of the proposed steering effort model through simulation analysis.Besides,this paper also studies the variable steering ratio of steer-by-wire system.Designing the variable steering ratio bases on the constant yaw rate gain of vehicle,and doing simulation analysis.Lastly,the circuit and program of road feel controller are designed according to the functional requirements of road feel simulation control system.Then processing and building the hardware-in-the-loop simulation platform to verify the effectiveness of the designed road feel simulation controller and control strategy.And simulation tests are carried out under different conditions.The test results show that the proposed road feel simulation method can driver with good road feel.