Sliding-Mode-Control-Based Robust Finite-Time Antisway Tracking Control of 3-D Overhead Cranes

In this paper, a robust finite-time antisway (i.e., antiswing and antiskew) tracking control method is developed for three-dimensional (3-D) overhead crane systems using a sliding-mode control (SMC) method. In order to control the overhead cranes, various tracking controllers have been developed to achieve satisfactory position tracking and swing suppression. However, along with the trolley and girder positions, both sway angles (i.e., swing and skew angles) should be controlled using the forces driving the trolley and girder for satisfactory transient response and safety enhancement through the suppression of sway angles even in the presence of uncertainties in 3-D cranes that have not been a major consideration in previous works. By introducing the sliding surface dependent on position tracking errors and the finite-time stabilization method for the skew angular rate, the proposed SMC-based robust finite-time antisway tracking control method is designed using the terms, each of which achieves position tracking control, antiswing control, and antiskew control. Accordingly, the proposed method can effectively suppress the sway motion of the 3-D crane and work well even with the variation in payload weight, the initial sway angles, and parameter uncertainties due to the payload weight uncertainty. The validity of the proposed method is supported by stability analysis and simulation and experimental results.