Nonlinear adaptive motion controller design for overhead crane systems

In the past years the problems of motion and stabilization control for an overhead crane system have become an interesting issue in the field of control technology development, due to the requirements of high positioning accuracy, small swing angle, short transportation time, and high safety,. Since the overhead crane system is subject to underactuation with respect to the load sway dynamics, it is very hard to manipulate the crane system in a desired manner, namely, gantry position tracking and sway angle stabilization. Hence, a nonlinear control scheme which incorporates both the cart motion dynamics and sway angle dynamics is devised to ensure the overall closed-loop system stability in this paper. To cope with parametric uncertainty, an adaptive version has also been presented for the nonlinear controller. In the developed control laws, the position error will be driven to zero while the sway angle is also rapidly damped to achieve minimal swing of the pendulum. Additionally, stability proof of the overall system is also given.