Development of payload sway suppression control technology simulated repowering for the crane

For improving safety and shortening the working time in payload transporting using an overhead crane without depending on the skills of the operator, we examined a control method for automatically suppressing payload sway. With the conventional control method, the residual payload sway, which is the payload sway after the crane stops, can be suppressed, but the overshoot, which is the moving distance of the payload after starting the stop operation, increases. We propose a payload sway suppression control method using simulated repowering control that simulates a repowering operation by a skilled operator. With this method, after the stop operation starts, the crane performs deceleration and subsequent trapezoidal waveform velocity drive. The parameters of the trapezoidal waveform are determined as follows. The payload sway caused by the deceleration is negated by the trapezoidal waveform velocity drive. In addition, the velocity and acceleration of the trapezoidal waveform to a range not exceeding the maximum value, to shorten the time width of the trapezoidal waveform. We conducted a simulation to verify the effectiveness of the proposed method. We confirmed that it can shorten overshoot compared with the conventional control method by suppressing the residual payload sway to various values of the pendulum length, which is the length from the rotation center of the rope to the center of gravity of the payload. We also confirmed that the proposed method does not worsen the residual payload sway and overshoot, even if the stop operation begins at various times, such as during acceleration, constant velocity movement, and deceleration.