A NON-TIME BASED STRATEGY FOR THE COORDINATED MOTION CONTROL OF HYDRAULIC ACTUATORS

Despite the extensive research concerning the motion control of a hydraulic systems, the coordinated motion (synchronized motion) of multi-axis hydraulic systems is still an open and challenging field. In such a frame, this paper presents an innovative non-time based control strategy for the coordinated motion control of multi-axis hydraulic systems. The proposed approach, named DRSC (Delayed Reference Synchronization Control) allows achieving the coordinated motion by delaying the position reference of each actuator on the basis of an action reference parameter, which plays therefore the role of a delayed time. Such a scalar variable is computed on the fly on the basis of a properly defined equivalent elastic error, which is in turn a function of the state of the system and of the position measurements. The theory developed is demonstrated through numerical simulations by applying it to the path tracking control of a two-axis hydraulic system.