Synchronous slew/translation positioning and swing suppression control for 4-DOF tower crane system

Abstract

This paper introduces a method to navigate the tower crane movement and suppress the payload swing synchronously. Special error signals are introduced, which bring the coupling of dynamics among various states of the crane and enable the control to meet the synchronous operation in practice. The special angle-dependent energy functions are designed as the candidate sub-Lyapunov functions for decoupling the states. The controller is then stepwise designed with the help of the dynamics model. The stability of the control is proven in the Lyapunov sense. Extensive simulations and experiments have been carried out to demonstrate the effectiveness of the proposed nonlinear coupling control. A popular control approach in the literature is chosen to compare with the current work. It is found that the proposed control is quite effective in suppressing the payload swing while tracking the pre-determined path at the same time.