Model-free sliding mode control for hydraulic actuators under high load

Despite the great potential of sliding mode controllers due to their inherent robustness properties, their utilization at the industrial level is still limited because of their complicated design and tuning. This study offers a Model-Free version of the well-established Super-Twisting algorithm for a class of electro-hydraulic systems, characterized by strong load forces. The design of a standard version of the controller is used as a starting point for its derivation, by matching the performance under certain hypotheses. The effectiveness of the solution is tested in simulation with an industrial case study, proving the effectiveness of the control action in a setup where realistic experimental conditions are utilized. The performance of the controller is evaluated under two tuning conditions, to assess the controller from both theoretical and practical perspectives, and its limits are explored.