Partial enhanced-coupling control approach for trajectory tracking and swing rejection in tower cranes with double-pendulum effect

As underactuated systems, tower cranes are usually regarded as single-pendulum systems in modeling. However, in many situations, such as when the mass of the payload and the hook are similar, they tend to exhibit more complex double-pendulum characteristics; in this case, it is more difficult to achieve both positioning and the elimination of swing performance by the traditional methods. To solve the engineering problems mentioned above more efficiently, the proposed controller is designed by increasing the coupling relation between the actuated and unactuated part, and meanwhile trajectories tracking ensures the safety of the positioning process and achieve actuators zero-initial output. The design and analysis are completed by the Lyapunov technique and LaSalle's invariance theorem, and selected experiments are implemented to validate the control effectiveness and strong robustness.