Control of Fast Crane Operation

Control of Fast Crane Operation 快速吊車控制方法

Control of Fast Crane Operation 快速吊車控制方法

Related references

1. T. Y. Kuo and S. C. Kang (2014). Control of Fast Crane Operation. Automation in Construction. Accepted in February.

Control of Fast Crane Operation 快速吊車控制方法 吊車運行速度的挑戰在於速度和安全性之間的權衡，提升吊車操作速度往往導致吊物擺動加大，增加發生意外的可 能性。雖然限制吊車運動速度以確保操作安全似乎是非常合理的，但累積起來的時間會影響整體工程的生產效率， 因此一個有經驗的吊車控制手往往以技巧和直覺來經常性的變化速度，以提升吊車作業效率與安全。本研究提出一 個小擺動角度的快速吊車控制方法，先利用單擺與雙擺的數學模型，作為理想化的吊車懸吊模型以發展減盪控制方 法，然後對控制方法進行分析與尋找相關的操作參數，最終再以數學模型計算實驗來進行方法驗證。我的方法分為 三個主要階段：階梯式加速度階段、等速度階段、階梯式減速度階段。在階梯式加速度階段使用兩個加速度的組合 ，以利減少振動並且控制擺角，接著在擺角為零的情形下達到最高運作速度。吊車隨後進入擺角為零且沒振動的第 二階段。第三階段為階梯式減速度階段是停止吊車運行並且控制吊物無振動，這個階段和階梯式加速階段相似僅加 速度方向相反。本方法的特色為操作時間與操作距離開根號成正比，因此在減少振盪的同時還加快了操作速度，十 分適合長距離快速操作。我也對建議方法進行穩定度測試。以達到簡單、穩定以及高效率的目標。最後使用一個高 精度的機器人手臂：庫卡機器手臂KR16，作為一個大型吊車的縮尺模式並進行實驗驗證本研究提出之方法。使用 我的建議方案在機器手臂運作中可以顯著降低高速吊車操作時的擺動，實驗結果也和數值計算結果吻合。

a1

a1

T 4

T 4

PT

z

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PT 4

y

a

P0

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PT 2

y y'

T 4

h

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a1

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One side sway of pendulum at different at T⁄2 and T⁄4 with a pivot acceleration a_1 (left diagram). The rotated system with the sum of the pivot acceleration and gravity pointing to the vertical (right diagram)

1 2

z' y'

T 4

vT 4 = a1

z' y'

hT

L g

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Schematic diagrams of h_(T⁄4) and v_(T⁄4) in a rotated coordinate system

Control of Fast Crane Operation

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 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 comparing 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% conďŹ dence 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 without the addition of any sensors the operator was able to control the sway of the crane cable.

Operation range

E

T 4

Computational extension

Ek 2 Ek1

Eu 3 Eu 2 t3

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Energy partition as a function of time.

E_u and E_k are the potential and kinetic energy respectively

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Rigging a beam element in the plane perpendicular to crane jib: (a) rigging system; (b) idealized model; (c) free body diagram (Kang 2005)

Control of Fast Crane Operation

Similar to Fig. 1 the schematic diagram for velocity as a function of time of the A-plan (a), the B-plan with t_2=0 (b), and the C-plan with t_3=0 (c)

Experimental implementation in KUKATM KR 16 CR robotic arm. Lateral view is in the bottom figure and the top figure is the bird’s eye view

Shih-Chung Jessy Kang sckang@ntu.edu.tw sckang.caece.net