The deadband control of the electro-hydraulic actuator of the motor-pump coordinated control

The electric-hydraulic actuator (EHA) of the motor-pump coordinated control is mostly applied into the flight control system, and it is a kind of power-by-wire (PBW) actuator with removing the central hydraulic power supply. The actuator system remains the hydraulic power partially, so the system has the characteristics of the hydraulic system such as: the compressibility of the hydraulic oil, friction and internal leakage of the hydraulic components etc., so the system possesses the inevitable deadband. A lot of the current literatures have expounded the deadband control of the hydraulic system, but the deadband control of the EHA is not fully elaborated, for it is very complicated system. Much analysis and control of the electric-hydraulic actuator didn´t include the deadband problem. In this paper the modeling of the EHA will be given, and many aspects including the deadband of the system will be thought over. The Fuzzy-Immune PID controller is applied to the EHA of the motor-pump coordinated control, and the deadband of the system is reduced, and it improves the performance of the EHA of the motor-pump coordinated control, and the foundation for further research is built for the higher performance of the electro-hydraulic actuator.