A Robust Controller Design for Electric Power Steering System Based on PI Current Loop

This paper investigates the robust controller of an electric power steering system. The design methods of the robust Hinfin mixed sensitivity controller are researched by the transfer functions model of EPS system, based on the classical PI current loop. The theoretical analysis and simulation experiments indicate that the proposed controller can improve the capability of low frequency noise enhancement and high frequency enervation in wide frequency band from the road, attenuate noise of torque sensor, exhibit good robust performances in assist tracking and anti-disturbance, and greatly improve the returnability, driver´s steering feel, handling characteristic.