Design of a Robust Adaptive Controller for a Hydraulic Press and Experimental Validation

This article aims to illustrate the design and validation of an adaptive controller developed for a hydraulic press. The controller architecture relies on an inner/outer loop structure, with an outer loop devoted to the control of the mechanical part and the inner one of the hydraulic subsystem. Moreover, adaptive laws aiming to estimate/compensate for external forces and disturbances that occur during the pressing phase and for leakage flow in the piston are present. This second estimate is used to maintain the performances acceptable in a wide set of operative conditions and for predictive maintenance. By using singular perturbation arguments, we show robustness to slowly increasing leakage gains, a typical situation in a real-world application. The control scheme is validated both on a simulative Simscape model and the real hydraulic axis.