工程吊車之物理行為模擬

Physics-Based Simulation of Detailed Erection Activities of Construction Cranes

紀宏霖(Hung-Lin Chi)

指導教授 ： 康仕仲

國立臺灣大學/工學院/土木工程學研究所/碩士(2007年)

https://doi.org/10.6342/NTU.2007.00968

摘要

在現代營建工程中，工程吊車往往扮演舉足輕重的地位，以鋼構建築工程為例，約有25%之工程費用與吊車及其作業直接相關，故吊裝施作之效率為營建工程探討的重要課題。現今電腦輔助軟體藉由合適的工程吊車模擬，提供數值化及視覺化的資訊，期能經由先期吊裝模擬獲取完善之施工資訊，避免實際施工上可能發生的問題。本研究之目的即在於整合物理模擬技術，進行吊裝作業的詳細模擬，提高擬真性與減少和真實施作過程中的差異。
研究中針對工程吊車之物理特性發展數值化之吊車模型，依據吊車各部件活動的性質，將此模型分為兩部分：可操作性機具模型(Manipulation model)與非操作性懸吊模型(Suspension model)，分別依據前序運動學(closed-form forward kinematics)理論與約束剛體動力學(constraint-based rigid body dynamics)理論來建構，前序運動學定義各關節連結的從屬結構及座標轉換運算，求得機具於虛擬環境中的幾何位置，如此配合操作員輸入的操作指令，便能動態地反映虛擬機具的動作行為；而約束剛體動力學描述關節的運動限制，於運動方程式中求取受限制力作用下的位置與方位資訊，表現出類似真實世界的物理行為。此機具模型包含輪、機身、吊臂等剛體部分；而懸吊模型則包含吊索與吊鉤等動態部分，前者藉由判明位置的改變量並視為外在受力來影響後者的運動，如此便能做出如吊索甩動的物理行為。
本研究針對吊裝作業模擬發展出一視覺化平台：Erection Director。此系統提供使用者自訂的彈性介面，並將上述之吊車模型實作於虛擬環境中，藉由即時的繪圖及物理引擎計算，模擬各種吊裝情境。其中特別將柱結構之吊裝作業與雙吊車協同起吊作業兩項目於平台上實作，經比對實際工程現場的吊裝方式，此兩項模擬皆能達到擬真的吊裝過程。
本研究建立實際吊裝作業之模擬技術，未來可延伸應用於吊裝計畫的完整模擬，提供規劃施工路徑的可行性檢測，讓計畫本身具有更高的可信度，亦可與現今自動化技術相輔相成，為吊裝作業提供更為完善與準確的解決方案。

關鍵字

剛體動力學 ； 前序運動學 ； 工程吊車 ； 物理模擬 ； 吊裝計畫 ； 虛擬實境 ； 機器人學

並列摘要

Construction cranes are one of the most important types of equipment in construction projects, which are essential to transport structural elements and building materials. Efficiency of crane operations may significantly influence the schedule and the cost of a construction project. One of the major problems is that the erection activities are very difficult to be simulated in details. Therefore, this research integrates physics-based simulation for generating practical erection activities that are relevant to complex situations of construction.
The major effort in this research is to develop a numerical model to simulate cranes to realize the physics-based simulations. The numerical model of crane can be generally divided into two sub-models: the manipulation model and the suspension model. The manipulation model was constructed by following the principle of closed-form forward kinematics. It facilitates the computation of the position and orientation of an articulated crane components with respect to the global coordinate by multiplying transformation matrices. The suspension model was formulated by following the principle of constraint-based rigid body dynamics. By describing the joint relationships between connected rigid bodies precisely, the realistic simulation of suspension objects can be obtained.
A prototype system, named Erection Director, was implemented to integrate the manipulation model and suspension model developed in the research. Because the physics-based simulation is available, the computer system allows users to simulate and realistically visualize the erection activities before these activities are performed in the field. Two example cases, one is column erection and the other is dual-crane cooperative erection, were presented to demonstrate the feasibility of these numerical models.
A physics-based environment for simulating detailed erection activities was built in this research. Because the high-fidelity visualizations can be generated in the virtual environment, the engineers can plan the erection activities precisely before the construction. This may increase construction speed, safety, and return on investment (ROI).

並列關鍵字

rigid body dynamics ； forward kinematics ； construction crane ； physics-based simulation ； erection planning ； virtual reality ； robotics

參考文獻

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