Energy-based Control of an Underactuated Crane System with a Flexible Cable and Large Swing Angle

In this paper, an effective energy based control technique for an overhead crane system with a flexible cable with large swing angle is developed. The studied crane system is categorized as a multi-degree underactuated system whose characteristics can initiate challenges in control design. Thus, simultaneously moving the trolley/payload and suppressing the payload swing and cable vibration is difficult. Due to such a difficulty, to overcome the complexities of the control problem, a corresponding energy-based control strategy will be proposed using linearized model and controlled Lagrangian method. The control objective is moving the payload to the desired position and at the same time, reducing the payload swing and suppressing the cable transverse vibrations. The controller guarantees both tracking of the desired payload position and active damping of payload swing and cable vibration. The simulation results are presented to demonstrate the dynamic behavior and effectiveness of the control system for an illustrative example of the crane systems with flexible cable moving a lightweight payload.