An Input Dead Zones Considered Adaptive Fuzzy Control Approach for Double Pendulum Cranes With Variable Rope Lengths

As commonly used tools for industrial production, overhead crane systems may suffer from the double pendulum effect in practice when the hook is not negligible or the payload cannot be directly considered a mass point, and most control methods designed for single pendulum overhead cranes are no longer suitable. Moreover, the actuators in practice cannot be ideal, and the existence of input dead zones will introduce much challenge during the controller design process. To improve the working efficiency, payload hoisting/lowering movement is necessary during the trolley horizontal movement, which implies that the rope length is variable and makes the entire system more complex. To solve these problems, an adaptive fuzzy control law is proposed for the double pendulum crane with variable rope lengths in this article, which can regulate the trolley displacement and rope length to the corresponding desired values within finite time and simultaneously suppress the hook's swing and payload's swing. Specifically, fuzzy logic systems are introduced with carefully designed adaptive laws to compensate for input dead zones for the double pendulum crane. Next, an effective regulation control method is proposed, and the convergence of actuated state variables, i.e., the trolley displacement and the rope length, is analyzed and proven by rigorous mathematical analysis. Then, the elimination of the hook's swing and payload's swing is further proven by using the property of the converging input bounded state. Finally, hardware experiment results demonstrate the performance of the proposed method.

Automated summary

Double pendulum effect in overhead crane systems can lead to control challenges, which are addressed in this article with an adaptive fuzzy control law. The method effectively regulates trolley displacement and rope length in variable length scenarios for improved efficiency and suppression of swings.