Abstract: Aiming at the requirement of the pilot surface control system with power by wire for the advanced fighter, a kind of the structure scheme of the displacement type of actuator with the reasonable electrical and hydraulic adjusting configuration is proposed, and its operation states and the main characteristics are discussed. On the basis of the mentioned work, the nonlinear state equation to describe the dynamic characteristics of this kind of the actuator is derived. Then, by means of the geometric control theory of the nonlinear control system, it is proved that this system satisfies the exact linearization condition, a kind of the optimal control law with the least time-error cost function(ITAE), and the problems of cross coupling and multiplication non-linearity existed in the actuator control system are successively solved. The control method proposed here founds the nonlinear control theory for the actuator with electrical and hydraulic compound control.

Key words: Actuator, Differential geometry, Electric servo systems, Hydraulic servo systems, Nonlinear control, Pressure pulsation Compound control Variable displacement Pump Noise