Robust Stability and Performance Investigation of Electrohydraulic Steering Control System

Abstract

The article introduces a robust stability and robust performance investigation of two embedded systems for control of electrohydraulic power steering in mobile machinery . They are based on advanced control techniques - linear-quadratic Gaussian (LQG) controller and H-infinity controller . The synthesis of the two controllers is performed via experimentally estimated SIMO state space model. The 30% input multiplicative uncertainty is introduced in estimated model. In this manner, a dead-band of proportional spool valve position is taken into account. This dead-band is constructively implemented to provide safety requirements of electrohydraulic steering. The robust stability and robust performance analysis are done by determining a structured singular value (μ) of the both closed-loop control systems, which are represented in M-Δ structure. The workability of the both systems are verified through simulation and real world experiments on laboratory test rig.