Control of an Axial Piston Pump using a Single-Stage Electrohydraulic Servovalve

Optimal control theory is applied to the design of a pressure regulator for an axial piston pump and single-stage electrohydraulic valve combination. The control valve has been modeled and an optimal control law has been formulated. The time response curves due to a step input in flow rate and in current input to the servovalve have been obtained for the open loop and for the optimal control system. The results have been compared to those in which the supply valve to the swashplate actuators was not modeled. Controlled system modeling of the servovalve significantly improves the system´s response frequency and pressure peaks.