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

Underactuated systems are widely utilized in many areas due to their distinctive advantages, such as reduction of structural complexity and reduction of control organization. However, because their input dimensions are fewer than state dimensions, the controllers can only operate on the actuated mechanism, while the remaining underactuated part is adjusted by the internal system dynamics [1]. Precisely due to coexistence of their complexity and advantages, an increasing number of researchers have devoted their efforts to the control of underactuated systems. Cranes are typical underactuated systems that are designed to transfer the payload, and traditionally, their dynamics have 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 per-formance 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. ? 2021 Elsevier Ltd. All rights reserved.