Modeling and control of an electro-hydrostatic actuator

Advanced electro-hydrostatic actuators offer a high degree of maintainability and combat survivability of aircraft flight control systems, because all the components necessary to operate the actuator are collocated with the actuator. The quantitative feedback theory robust control method is used to design a controller for the actuator. The impact of parameter variations, sensor noise, and flight condition variability are explicitly considered in the design process. The controller utilizes a two loop feedback controls structure. The resulting linear design is not only robust with respect to plant parameter variations, but is also insensitive to the effects of sensor noise. Furthermore, the actuator's phase lag is reduced by incorporating phase constraints in the QFT design paradigm; thus, improving the performance of the overall flight control system.