Fully Actuated System Approach to Adaptive Control for Underactuated Tower Crane Systems

Motivated by the fully actuated system approach, a novel adaptive control for the uncertain underactuated 4-DOF tower crane system is investigated in this paper. Firstly, a general uncertain tower crane error model is provided, where the lumped uncertainty is only required to meet the bounded assumption. Then, the lumped uncertainty is approximately by the radial basis function neural network structure. Subsequently, the adaptive control method is constructed to guarantee that the positioning error asymptotically converges to 0 and the payload swing is suppressed and eliminated rapidly. The closed-loop stability is proven strictly based on the Lyapunov stability theory. To the best of our knowledge, it is the first fully actuated system approach-based method for tower crane systems under systematic uncertainties and external disturbances, which is designed without any linearizing operation. Experimental results suggest that the designed control method is of satisfactory efficiency and robustness.