A new adaptive control design for a quadrotor system with suspended load by an elastic rope

As an extended application of unmanned aerial vehicle (UAV), the system of a quadrotor with suspended load has a good development prospect because of its flexible performance and stable structure. However, the suppressive swing of the load and the consequently swaying of the UAV may cause crashes during the flight transportation. In order to solve the above problems, this paper introduces a rope with elasticity and damping of the transportation system of quadrotor with suspended load, which reduces the swing of the load by increasing the dissipativity of the system, and establishes the dynamic model of the proposed system. Then a new adaptive controller with unknown mass parameter is designed based on energy analysis method. The stability of the closed-loop system is proved by Lyapunov method and LaSalle’s invariance principle. Numerical simulation results show that the proposed adaptive controller can eliminate the effects of the uncertain mass, and the proposed system can reach the specified position rapidly and the swing of the load can converge quickly under the action of the controller, which avoids flight accidents.