Control of fast crane operation

Abstract

Abstract This research provided a simple vibration control method for fast crane operation using an open-loop control approach. With the equations of double pendulum motion, we used two related acceleration and deceleration to propose a three-stage method consisting of (1) piecewise acceleration, (2) constant speed, and (3) piecewise deceleration. Our method is to reduce the sway angle and to reach high speed operation. The proposed method maintains a small sway angle in fast speed while the other open-loop methods do not. Our method is studied both numerically and experimentally. We found out that in numerical simulations the operational time was approximately proportional to the square root of the operation distance; a fourfold increase in distance only required a 200% increase in operational time. The method is stable with respect to the 10% variations of system parameters. In comparison to a common method in 100 m operation distance, the operation time is 25% faster when the maximum sway angle is the same, and the sway angle is 44% smaller when the operation time is the same. We conducted a KUKA Robot KR 16 experiment to validate the proposed method. The KUKA experiments suggest a four times smaller vibration magnitude in the proposed method. Moreover, the numerical simulations of the proposed method compare favorably with the KUKA experiments with 95% confidence interval. With the scaled parameters, the KUKA experiment corresponds to 30 s operation time and 180 m operation distance in the real crane situation. The proposed method is safe and fast, and without the addition of any sensors the operator was able to control the sway of the crane cable.