臺灣博碩士論文加值系統

隨著科技與國防發展日新月異，工具機的加工變得越來越複雜，切削加工時發生機台碰撞的情形亦更加頻繁，這些撞擊可能造成加工件或機台組件的損壞，尤其於五軸機的加工，為了確保機台於加工生產中不因路徑規劃錯誤而造成工件與機台碰撞，最簡易的方式為透過模擬軟體將規劃之路徑進行切削模擬，或於加工進行前使用單節執行或手輪模擬，以確保不會發生碰撞，但相對的浪費許多時間，故機台即時碰撞預防之功能顯得更為重要。不過碰撞預防技術目前仍屬國外發展較為成熟，國內目前應用上仍為少數，其原因大致可分為兩項，其一國內工具機廠之控制器多半使用國外控制器，如FANUC、Mitsubishi、Siemens與Heidenhain等，各家控制器規格、插補與運算等定義皆不同，且系統開放性較低，對於二次開發部分技術門檻與成本較高，故國內廠商較多無法針對這類控制器進行二次開發；其二在於碰撞模擬環境成本昂貴，目前國際上常見之模擬環境為英國MachineWorks與德國ModuleWorks，因授權成本昂貴，因此無法被廣泛地應用。有鑑於此，本研究擬開發一套簡易碰撞預防系統，提出一種低成本碰撞模擬環境之選項。此系統主要分為兩個部分，其一是運用目前成熟之遊戲開發引擎Unity進行碰撞模擬環境建置，並利用SolidWorks將機台幾何外型繪製與組裝，透過C#建置模擬環境中機台模型運動腳本；其二透過商用軟體開發其操作介面並將五軸CNC控制器與Unity兩者相互整合，使其能夠達到近似同步之虛實整合，同時利用新代提供之控制器模擬機於背景先行預讀和執行加工程式解譯與插補，藉此使本研究之系統能夠達到碰撞預測。理論方面，於模擬環境中圖形干涉偵測在遊戲引擎多半使用分離軸定理(Separating Axis Theorem)與包覆體(Bounding Volume)進行重疊測試，不過由於包覆體含有多種幾何形式，故本研究針對S. Gottschalk所提出之包覆體對於重疊測試速度之影響進行實驗。實驗顯示，以Sphere進行包覆之物件其重疊測試速度所耗費時間最少，不過其觸發距離與實際碰撞距離相差19.26%，而以多重Box進行包覆重疊測試所耗時間最長，但觸發距離與實際碰撞距離相差僅1.46%，雖然兩種方式外型與偵測時間落差看似很大，但其實於畫面更新率60FPS下兩者偵測時間僅相差0.27s，於畫面更新率100FPS下時間相差0.16s，因此在電腦規格佳狀態下為避免碰撞距離之誤判，建議選用多種包覆體進行機台幾何外型包覆。在自動執行狀態下，因控制器模擬器以實際機台之2倍運作速度進行加工程式解譯與插補，若實際機台以150%進行加工，模擬器還是會超前實際機台運作速度之1.3倍，並於背景下執行碰撞偵測，因此可達到先行碰撞預測之功能。

Owing to the new technology of aerospace and military advances, the processing has become tough in machine tools, it may increase the risk of collision between the tools and the parts, it may damage to the workpiece or machine unit, especially on the five-axis machine. In order to ensure the collision will not happen during processing on machine tools, the easiest way is to simulate the NC code in simulation software or use single block and handwheel simulation mode before processing. But this way may delay in the production cycle, that is why the real-time collision avoidance during the processing is more important. However, this technology is still relatively mature in foreign countries, the machine tool applications with the collision avoidance system is still a minority in Taiwan, reason can be divided into two. First, most Taiwan manufacturer uses the European or Japanese controller, such as FANUC, Mitsubishi, Siemens, and Heidenhain, etc. Each controller manufacturer has their own system definitions like the parameter of the controller, PLC, loop of control, etc. Because their system's degree of openness is low, customization of HMI, PLC or the value-added system needs higher cost and higher technical standard. Secondary, the common NC simulation environments in the world are MachineWorks[4] and ModuleWorks[5], most of the worldly famous machine tools manufacturers are using this two simulation software to realize the machine tools collision detection. However, those environments need the higher fee. In Taiwan, most machine tools manufacturers are mostly SMEs. They may not afford the software licenses, that is why cannot be widely used. In this study, we used the game engine to develop a collision avoidance system of machine tools for low cost and quick setup applications. It can make the physical machine and the virtual reality to approximate the synchronization and realization of the cyber-physical system. The collision avoidance system of the study can be divided into two parts. First, the model of machine tools is built using the game engine named Unity and using the 3D design software named SolidWorks for the realization of the simulation environment of machine operation and processing. At the same time, use C# to create machine model motion script to realize the real-time machine tools model motion. Secondary, a collision avoidance system with an HMI layout is integrated the physical CNC controller, Unity and controller simulator using LabVIEW software. At the same time, the simulator of CNC controller can pre-read NC codes in the background for Interpretation and interpolation NC programming. In this way, can make it possible to achieve approximate synchronization and realize cyber-physical system. The executive speed of the virtual machine tools made from Unity software is twice physical machine tools during the processing. Results showed that if the feed rate of the physical machine tools is 150% during processing, the executive speed of virtual machine tools can also run at 1.3 times for pre-reading NC codes. The collision detection test time of the bounding type in Unity software taking Sphere as the shortest time, but the misjudgment of the collision distance is 19.26%. The longest time is used bonding type of Box for customizing, but the misjudgment of the collision distance only 1.46%. However, two type of bounding volume the difference in time only 0.27s in Unity software with 60FPS, at the 100FPS is only 0.16s. In the case of the excellent computer, specifications to reduce collision misjudgment rate, using the different bounding types for customizing the graphics bounding volume is the best choice for the collision avoidance system. The study realizes the real-time collision avoidance for Five-Axis CNC machine tool based on the cyber-physical system.

摘要 ....i
英文摘要(Abstract) ....ii
誌謝 ....iv
目錄 ....v
表目錄 ....vii
圖目錄 ....viii
符號說明 ....xi
第 一 章 緒論 ....1
1.1 研究背景與動機 ....1
1.2 研究目的 ....2
1.3 論文架構 ....3
第 二 章 文獻回顧 ....4
2.1 虛實整合製造 ....4
2.2 虛擬實境(Virtual Reality) ....4
2.3 國內外相關研究 ....6
2.3.1 虛實整合製造相關研究 ....6
2.3.2 碰撞偵測系統開發相關研究 ....10
第 三 章 研究架構與方法 ....15
3.1 研究架構與流程 ....15
3.2 硬體及系統架構 ....15
3.2.1 五軸CNC工具機設備 ....16
3.2.2 五軸CNC控制器介紹 ....17
3.2.3 五軸同動加工介紹(RTCP) ....18
3.2.4 PC-Based系統架構 ....19
3.2.5 Unity3D環境介紹 ....20
3.3 工具機系統通訊與控制 ....21
3.3.1 新代控制器通訊連線 ....21
3.3.2 PLC程式撰寫與控制 ....24
3.4 工具機3D虛擬平台建立 ....27
3.4.1 機台幾何外型建置 ....28
3.4.2 STL(Stereo Lithography) ....29
3.4.3 各部位零組件運動腳本設置 ....30
3.5 碰撞檢測 ....32
3.5.1 碰撞包覆體 ....32
3.5.2 分離軸定理 ....35
第 四 章 實驗結果 ....43
4.1 機台運動模擬系統 ....43
4.1.1 Unity運作模式 ....44
4.1.2 碰撞事件建置 ....47
4.2 虛實整合系統 ....49
4.2.1 控制器模擬機 ....50
4.2.2 PC-NC虛實整合人機介面 ....50
4.2.3 虛實整合通訊方式 ....51
4.3 實驗結果分析與討論 ....53
4.3.1 包覆體型式差異 ....53
4.3.2 FPS於碰撞偵測中之影響 ....56
4.3.3 碰撞訊號觸發實驗 ....58
第 五 章 結論與未來展望 ....64
5.1 結論 ....64
5.2 未來展望 ....64
參考文獻 ....66
Extended Abstract ....68

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