Analysis of the suspended flexible body's vibration behavior carried by overhead crane

Abstract

In helical type fusion reactor, a spiral coil is used for the internal structure, which results in very severe structural constraints and is a major obstacle to the maintenance systems. Due to structural restrictions, it is necessary to perform replacement work using an overhead crane while control vibration and interference with other parts. Furthermore, the payload has thin plate structure, then the deterioration of control performance is expected due to the influence of shape and flexibility. Therefore, the influence of the deterioration should be evaluated for efficient maintenance operation. This research deals with a feed-forward recoil control method that is constrained to the target trajectory by combining feedforward and nonlinear optimization calculation. The control method is applied to the two-dimensional payload with two-point suspension, the influence of the control when the payload is flexible body is confirmed, and the control system is examined. Since the rope length changes with time, the two-point suspended overhead crane model is represented by a linear time-varying system. The input shaping method, which is a feed-forward type compensator, is used for vibration control. Optimization calculation is performed to obtain the rope length profile that follows the target trajectory. The validity of the proposed method by numerical analysis was confirmed and the proposed method, was evaluated when applied to flexible body suspended matter.