Research Of Two-degree-of-freedom Positioning And Anti-swing Control Methods For Overhead Cranes

The bridge crane is becoming more and more important in the industrial production as a handling tool. It is widely used in ports, working shops, and other industrial productions. The various external factors lead to the low efficiency, the long time to reach desired position, and the large swing angle. And because of the large number of components, the environment of bridge crane is always full of dangers. Therefore, based on the present controllers, this paper proposed several new methods to improve the dynamic and static performance of system, so that the bridge crane could work in a safety, stable environment. All working can be concluded as follows:Firstly, the Internal Model Control(IMC) theory had been adapted to reach the purpose of anti-swing control of bridge crane. Its combination with two degree of freedom control reduced numbers of parameters in the controllers. The set-point response and load-disturbance response were regulated independently, bringing the control system good characteristics of command tracking and disturbance as well as robustness.Then, a two-degree-of-freedom sliding mode controller(SMC) was proposed for the anti-swing and positioning control of overhead crane. The feed-forward controller was simple and had only one adjustable parameter. The feedback controller was designed based on the principle of sliding mode control. A new control law was presented to suppress the chattering and improve reaching speed. Theoretical analysis and simulation results show that the proposed method has a better performance.At last, a method of two-degree-of-freedom robust controller has been proposed to improve the dynamic property and robustness of crane system, the robust controller was adapted to solve the problem of inaccurate model. The feedback and feed-forward controllers were got by the H? theory. The Matlab simulations proved that this method had a better performance.