The attitude control of rotorcraft aerial manipulator with saturated control action

The rotorcraft aerial manipulator (RAM) system is a nonlinear system with strong coupling characteristics, which can actively operate the target object in the flight state. When the manipulator of RAM is moving, the system may suffer from attitude disturbance to cause control input saturation. This paper designed a cascade controller constituted by PID controller and conditioned super-twisting algorithm (STA) for UAV attitude control, which can ensure stability and robustness of system and mitigate windup effect of control action. Besides, the extended state observer (ESO) is utilized to estimate the disturbance. Finally, through the simulation experiment on MATLAB, the validity of the controller is verified. The results demonstrate the robustness and anti-windup effect of the proposed controller.