DATA-DRIVEN CONTROL OF HYDRAULIC SERVO ACTUATOR BASED ON ADAPTIVE DYNAMIC PROGRAMMING

The hydraulic servo actuators (HSA) are often used in the indus -try in tasks that request great powers, high accuracy and dynamic motion. It is well known that HSA is a highly complex nonlinear system, and that the system parameters cannot be accurately determined due to various uncer-tainties, inability to measure some parameters, and disturbances. This paper considers control problem of the HSA with unknown dynamics, based on adap-tive dynamic programming via output feedback. Due to increasing practical application of the control algorithm, a linear discrete model of HSA is con -sidered and an online learning data-driven controller is used, which is based on measured input and output data instead of unmeasurable states and un-known system parameters. Hence, the ADP based data-driven controller in this paper requires neither the knowledge of the HSA dynamics nor exosystem dynamics. The convergence of the ADP based control algorithm is also the-oretically shown. Simulation results verify the feasibility and effectiveness of the proposed approach in solving the optimal control problem of HSA.