機械視覺之加工補正研究

Abstract

本研究的目的是使用自由軟體，開發出在數控加工機上，運用自由軟體OpeCV機械視覺(Machine Vision)函式庫、dxflib DXF轉換函式庫與OpenGL繪圖函式庫，以商用開發工具Visual Studio C++ MFC為平台，加上 Dalsa Sepera LT CCD開發函式庫，新代控制器OCAPI整合開發介面，整合撰寫出一套完整的加工補正系統。 數位噴印的產品製程中，產品特性是輕薄、印出的內容會有小變形，若要將印製的圖形以無治具的方式切下，傳統的NC 加工的補正方式是達不到的，因為尋找加工基準將極為困難而無效率，原因就是工件極薄，上料後的位置，前後無法一致，若又遇到需將工件沿變形的輪廓切下，傳統的加工補正方式幾乎一籌莫展。 若以機械視覺做為加工補正的工具，可以達到無治具、小變形之加工補正。利用工件輪廓邊緣，印上定位點，做為工件位置定位與輪廓變形的參考依據。前述定位點以機械視覺辨識出位置後，計算出位置與加工路徑補正，加入圖形座標中。之後圖形座標轉出成為NC程式碼，直接透過新代控制器OCAPI函式庫，循序發出加工單節指令至控制器中進行加工。

The study used freeware to integrate and write a comprehensive processing/compensation system for numerical control machines that employs freeware OpeCV machine version library, dxflib DXF conversion library, and OpenGL graphic library. It also applies the commercial development tool Visual Studio C++ MFC as the platform, as well as the Dalsa Sepera LT CCD development library and the Syntec controller OCAPI for integrating and developing the interface.

During the digital print product manufacturing process, products have the characteristic of lightness and thinness and the printed content shows slight transformation. The compensation method of traditional NC processing cannot be used to cut printed images without gauges. Because of the extremely thin work pieces, and inconsistent positions after materials are loaded, identifying the processing datum is difficult and inefficient. We also cannot use the traditional processing/compensation method to cut work pieces along the outlines of distortions.

Machine vision can be used as a tool for processing and compensating to achieve slight distortion and no jig and compensation. We marked anchor points along the outline of the work pieces as a reference for their positioning and outline distortion. After the positions of the anchor points were identified using machine vision, the positions and processing path compensations were calculated and were added to graphics coordinates. Then, the graphics coordinates were converted into NC codes. Finally, we used the Syntec controller OCAPI library to send processing single-block commands to controllers in sequence for processing.