Low-Complexity Prescribed Performance Control for Unmanned Aerial Manipulator Robot System Under Model Uncertainty and Unknown Disturbances

This article presents a trajectory tracking control method for the unmanned aerial manipulator robot system (UAMRS) under model uncertainty and unknown disturbances. More specifically, a low-complexity prescribed performance controller is proposed to effectively reduce the design complexity and achieve the prescribed transient and steady-state performance. First, the dynamics model of the UAMRS is analyzed and modeled, where the unmeasured internal interaction generated by the coupling effect and the random environmental disturbances are considered simultaneously. Then, utilizing the property of prescribed performance, the UAMRS with model uncertainty and external disturbances can guarantee preferable trajectory tracking responses, where the nonlinear disturbance observer is used to estimate and compensate uncertainties and external disturbances. Moreover, the proposed controller defined by simple expressions does not require accurate knowledge of the UAMRS, which is of low complexity and can effectively reduce the amount of calculation. The stability of the proposed controller is analyzed. Finally, the performances of the proposed scheme are demonstrated by the numerical simulation comparisons and real-world experiments, where a quadrotor with a 3-DOF onboard active manipulator is adopted in outdoor experimental validations.