Fractional integral sliding mode nonlinear controller of electrical-hydraulic flight simulator

Electrical-hydraulic flight motion simulator is the key equipment in hardware-in-the-loop testing of flight control systems. It can accurately reproduce, in real-time, the flight motion of aerial vehicles under laboratory conditions, which has great economic value and plays a very important role in the national defense. Based on fractional integral sliding mode surface, a nonlinear robust controller was proposed to improve its dynamic tracking accuracy. This nonlinear robust control approach introduces fractional order calculus in integral sliding mode controller, which can further improve transient performance and offer more degrees of freedom. In presence of strong disturbance torque, parametric uncertainty and nonlinear friction, the globally asymptotic stability of developed nonlinear robust controller was proved via Lyapunov analysis method. Under various working conditions, comparative simulation results of outer-axis's motor in a type of flight simulator demonstrate the effectiveness of the proposed nonlinear robust algorithm, which can guarantee transient performance and effectively improve the robustness.