Model-Based Control of a Pressure-Compensated Directional Valve With Significant Dead-Zone

Abstract

Hydraulic systems on mobile manipulators and industrial systems often come equipped with pressure-compensated proportional directional control valves with significant dead-zone. These kind of hydraulic valves are well suited for open-loop applications with an operator in control. However, designing closed-loop control for such systems is a challenging task. In this study, we propose a model-based control method for such valves to increase the performance of the current state-of-the-art in industrial robotic manipulator control. The proposed control method rigorously addresses the dynamics of a hydraulic manipulator system with dead-zone compensation for pressure-compensated directional control valves. The proposed method is evaluated with experiments on a commercial heavy-duty breaker boom with Sauer-Danfoss PVG 120 valves. The experimental results show accurate control of the manipulator despite the used slow-response load sensing valves.