Research on Control of Active Optimal Load Sensing Electro-Hydrostatic Actuator

Electro-Hydrostatic Actuator (EHA) is an actuator of the power by wire (PBW) actuation system applied to more/all electrical aircraft (MEA/AEA), which is helpful to improve the reliability and efficiency of EHA in aircraft. EHA is highly integrated local closed hydrostatic system without external pipeline, therefore when working at low speed and high load, the heat generated by the motor is difficult to be conducted and dissipated rapidly resulting in rapid temperature rise. Active optimal load sensing EHA (AOLS-EHA) is a typical double inputs and single output system, in which the displacement of the variable pump is adjusted by controlling the load pressure. In this paper, on the basis of the optimal control algorithm, the heat value of the motor is taken as optimal performance index, the motor speed is controlled actively and the displacement of variable pump is matched with load, causing the AOLS-EHA to control pump discharge pressure with optimal load sensing. A specific nonlinear state equation of AOLS-EHA is built in this paper. The result of simulation shows that AOLS-EHA is feasible and the heating of motor can he effectively reduced while dynamic performance of the system is not reduced significantly.