Active pendulation control system for the underactuated davit

This paper considers an active control system that reduces pendulation of suspended loads for the underactuated characteristic of the three-dimensional davit system. The dynamic model is established with the Lagrange equation and the anti-swing controller of davit system is designed based on the system´s energy. Compared with other anti-swing controllers of the marine davit, it adopts active pendulation control and doesn´t need approximately decoupling and linearization. And it still can restrain pendulation of load effectively, even though the mass of load and the length of cable are uncertain. The stability of closed-loop system is proved by Lyapunov stability theory and LaSalle invariance principle. Simulation results demonstrate that the active pendulation control system is effective.