Position Servo Control for Dual Piezoelectric Pumps-Based Electro-Hydrostatic Actuator with Active Rectification Valve

With the advantages of high integration, high precision, and fast response, piezoelectric material-based electro-hydrostatic actuators (PEHAs) have become the main development direction of power by wire. Most of the current research on PEHA focuses on the new structural design to achieve speed regulation and directional change. However, to ensure the maneuverability of the aircraft, advanced and effective position servo control is necessary. To realize the position servo control of PEHA, the position servo control methods of a dual piezoelectric pumps-based electro-hydrostatic actuator with an active rectification valve (DPEHA) were investigated in this paper. Based on the built mathematical model, the output flow characteristics of DPEHA were obtained. On this basis, three control methods, pure phase control, amplitude & phase control, and frequency & phase control are proposed and experimentally verified. The experimental results indicate that the control accuracy of pure phase control is better than that of amplitude & phase control and frequency & phase control. When tracking the target displacement with the peak-to-peak value of 4.8 mm and frequency of 0.6 Hz, the root mean square error of pure phase control is 0.07 mm, which is 46 % lower than that of amplitude & phase control and 67 % lower than that of frequency & phase control.