Robust Position Tracking for Electro-Hydraulic Drives Based on Generalized Feedforward Compensation Approach

This paper presents the development of a robust tracking control concept based on accurate feedforward compensation of hydraulic valve-cylinder drives. The proposed feedforward gain is obtained by use of a generalized description of the valve flow that takes into account any asymmetry of valves and/or cylinders, not assuming these asymmetries to be matched, and utilizes pressure measurements. Hence the proposed compensator is generally applicable to any such drive. Simulations show that the proposed compensator poses superior performance and robustness when subjected to strong perturbations in supply pressure and coulomb friction, compared with a conventional constant gain type feedforward compensator.