Model-free Controls of Manipulator Quadrotor UAV Under Grasping Operation and Environmental Disturbance

摘要

Quadrotor unmanned aerial vehicle (UAV) is an ideal carrier for air transportation because of its simple structure and strong maneuverability that can complete vertical take-off and landing and hover operations. In recent years, the combination of quadrotor UAV and manipulator has attracted the most extensive attention. However, the quadrotor UAV will be significantly interfered with installing the manipulator, making control difficult. In this paper, a complete mathematical model of the manipulator quadrotor UAV is established. The model describes the interference of the manipulator and its operation to the quadrotor UAV. In order to suppress the interference caused by the manipulator, it is necessary to select the appropriate controller. Three model-free control algorithms are designed: proportional-integral-derivative (PID), sliding mode control based on RBF neural network (RBF-based SMC), and high order differential feedback controller (HODFC) and the derivation of RBF-based SMC and HODFC and the proof of closed-loop system are given. The PID controller has the worst anti-interference performance through the analysis of simulation experiments. On the other hand, RBF-based SMC has a time delay, HODFC has the strongest robustness to disturbance and excellent rapidity, which is an ideal method to control manipulator quadrotor UAV.