Eid S. Mohamed^1,, Saeed A. Albatlan²

With the continuous development of vehicle and electronic industry, Steering by Wire (SBW) is replacing the traditional steering device of vehicle. The SBW is reproducing realistic steering feel, improving the vehicle returnability and it reduces the oscillatory effect of the steering system when the vehicle passes through an uneven road. This paper aims to present an overview of the SBW with integrated hydraulic power steering (HPS) in commercial vehicle. The mathematical model has been used to evaluate the performance of SBW system by using Matlab/Simulink software package, a PID controller and Linear Quadratic Regulator (LQR) optimization techniques are employed to arrive at an optimal controller for the SBW to monitor the system dynamic behavior and stability characteristics. The test rig of SBW system showed a great benefit in modifying a conventional HPS system to be electronically SBW. Necessary sensors and actuators replaced the conventional steering wheel. A microprocessor and interfacing circuits are designed to active control of DC motor. Also a SBW should be considered as requirement for a DC motor actuator vehicle steer angle for operating at given desired reference value and a proper torque to boost undergoing for operating under different conditions. The steering response of practical tests depends upon uncertain quantities like front axle weight, damping and a varying friction condition. Experimental results of SBW show that high performance and robustness are achieved.

steering-by-wire, steering feeling, hydraulic power steering, steering torque, SBW dynamic model, a stability analysis of SBW, PID controller and LQR optimization techniques