Application of Singular Perturbation Theory to Hydraulic Pump Controlled Systems

In this paper, we use singular perturbation theory to simplify control designs for hydraulic systems and to make designs more feasible for engineering practice. The paper presents the derivations, simulations and experimental tests of control laws for a hydraulic displacement-controlled actuator. Analyses of applied conditions and stability proofs are provided. The developed control design procedure is simplified and is robust to variations in the bulk modulus. The proposed design is simulated with cases of different control input models. Experiments are conducted on a novel hydraulic circuit. The results show that position tracking error exponentially decays and control efforts are dominated by low-frequency signals.