Adaptive anti-swing control strategy for three-dimensional double-pendulum variable-rope-length overhead cranes with enhanced pendulum angle suppression under initial input limitation

Abstract

This paper focuses on the research of anti-swing control strategy for a three-dimensional double-pendulum variable-rope-length overhead crane. The model is highly challenging due to its high-dimensional coupling and the complexity of double-pendulum effects. Addressing key issues such as excessive motor starting torque, uncertainty in system parameters, and excessive swing angles of the hook and load during crane transportation, this paper proposes an adaptive anti-swing control strategy under initial input constraints. This strategy improves the driving force model by introducing a hyperbolic tangent function, effectively reducing the initial swing angle of the crane’s double pendulum and enhancing the smoothness of system startup. Meanwhile, an adaptive rate is designed to estimate unknown system parameters online, thereby improving transient anti-swing control performance when system parameters change. Additionally, a three-dimensional double-pendulum enhanced swing angle suppression controller is developed, significantly enhancing the system’s robustness. The system’s ability to achieve asymptotic tracking is rigorously verified through Lyapunov techniques and LaSalle’s invariance principle. Simulation and experimental results demonstrate that the proposed control strategy exhibits excellent control performance.