Abstract: The traditional control methods can not satisfy the performance requirements when the methods are used to control threeaxis hydraulic simulator that is difficult to get the explicit mathematical model, and has many disturbances and diversified system parameter changes. The basic theory of predictive functional control (PFC) and its various algorithms applied to different control systems are introduced and analyzed and the suitable PFC algorithm is applied to threeaxis hydraulic simulator. The PFC-PID cascade control strategy that combines PFC with PID control is presented to satisfy the control index of threeaxis hydraulic simulator. Internal loop of the system adopts PID control strategy in order to eliminate the influence of different disturbances. The internal loop and threeaxis hydraulic simulator constitute the generalized control plant of PFC. The response speed and the good synthesis performance index are obtained by PFC in the extern loop. The simulation results indicate the efficiency and superiority of the PFC-PID controller.

Key words: hydraulic simulator, cascade control, predictive control, predictive functional control(PFC), generalized control plant