Design and Control of Electric Power Assist Steering (epas) Electronic Control Unit (ecu)

The main focus of this paper is to review the most recent trends in the various control methodologies for the Electric power assist Steering (EPAS) ECU. It covers the various aspects of design, modeling, simulation, analysis and control. The EPAS controller drives the electric motor to provide the assist torque. Stability compensators are used to attenuate the torque ripples caused by the mechanical and electrical components. The control system must be stable and robust against modeling uncertainties. Most classical controllers employ multiple tuning parameters which are difficult to implement in real-time systems. Intelligent controllers employing yaw compensation and return compensation reduce the damping created by undesirable road conditions, high vehicle speed. The EPAS control system has multiple objectives requiring fine tuning of several parameters, hence it should be designed such that the unwanted disturbances created by the non-linear effects of friction, backlash and noise should be rejected enhancing system performance. The major purpose of this paper is to identify and address the challenges and critical issues involved in the processes of designing and testing the ECU.