An adaptive tracking control method with swing suppression for 4-DOF tower crane systems

As an efficient transportation tool, a tower crane is widely used in construction sites. To improve the working efficiency, some automatic control methods have been proposed for tower crane systems, including some open loop methods, such as input shaping methods, trajectory planning methods, and so on. However, generally, tower cranes usually work in outdoor environment, which are sensitive to unavoidable external disturbances. Additionally, accurate system parameters are hard to obtain, which increases the control difficulty of the tower crane system. Considering these factors, in this paper, we propose an adaptive tracking control method, which achieves satisfactory tracking performance w.r.t. parameter uncertainties and external disturbances. Specifically, utilizing the passivity property, a shaped energy-like function is designed as a Lyapunov candidate, based on which, an adaptive tracking controller is proposed to deal with parameter uncertainties. Using Lyapunov stability analysis, together with LaSalle's invariance principle, the closed-loop system is proven to be asymptotically stable. At last, a series of experimental tests are implemented to illustrate the satisfactory performance of the proposed method. (C) 2019 Elsevier Ltd. All rights reserved.