Dynamic modelling and swing control of a quadrotor with a cable-suspended payload

Abstract

A quadrotor is a highly nonlinear system due to the presence of aerodynamic factors such as Coriolis and gyroscopic effects when in flight. In meeting todays’ demands, the applications of quadrotors have been extended to include transportation and therefore, the study of Quadrotor Suspended Load (QSL) systems has become equally as important. However, the presence of the suspended load further complicates the quadrotor system as there is strong coupling with the load and excessive load swinging. This is a problem which forms the basis for this work. This project begins by providing a mathematical description of the QSL system using Euler-Lagrange equations as they are much simplified, yet encompass the many factors present during quadrotor operation and subsequently control excessive payload swinging. The main strength of this work is that unlike other previous work, it covers 8 degrees of freedom (8 DOF) in representing the system dynamics. This presents a much more comprehensive and definitive way of describing the quadrotor and payload positions. Input shaping is used as the swing controller as it is more practical and has been used for swing control of other systems. Validation of the swing controller performance is done using MATLAB SIMULINK. Unlike other controllers that require sophisticated algorithms for their implementation, input shaping will be used as a swing controller as it is much simplified in handling excessive load swinging.