Abstract
The closed-loop control methods of bridge crane systems adopt the real-time signal feedback to improve the performance of the systems. The energy-based closed-loop control method of bridge crane systems can be used to design the controller by constructing the energy function of the system, which avoids the direct analysis of the complex motion state of the systems and has the clear physical significance. However, the conventional energy-based control methods have some problems, including slow response, poor performance of eliminating pendulum, and less parameters reflected by the control law. A novel load energy coupling-based underactuated control method for bridge cranes is proposed. The relationship between the energy of the bridge crane system and the energy of the load system is analyzed with the dynamic model of the two-dimensional bridge crane. The coupling function based on the load displacement and swing angle is constructed. The driving force of the system is obtained by Lyapunov method, and the control law is designed. The boundedness and convergence of the closed-loop control system are explained by the principle of LaSalle invariance. With the comparison experiments and results analysis, it is shown that the proposed method can obtain the better performance of eliminating swing and realize the accurate positioning of the trolley. It also reflects that this proposed method effectively reduces the dependence on model parameters and simplifies the control law.