CNC機具與運動模擬平台協同運動之研究

Abstract

為因應未來高精度與高進給的自由曲面加工要求，本文開發多軸交叉耦合預補償法(MCCPM)做為複合型五軸工具機的控制核心，其構型是由六軸史都華平台搭配X-Y table，此工具機具備有平台高精密定位等優點，同時X-Y table更可以彌補平台工作空間不足的缺點。文中所設計的加工規劃可以有效擴大CCPM的運用範圍，此外，所提出的線上插補器設計除了能有效減低在加工過程中電腦的計算負擔外，高階自由曲線的運用概念更使得工具機的加工能力大為提升。其中定義的方向輪廓誤差與方向預補償更是一大突破，使得MCCPM可以達到在曲面加工時的表面精度要求；為配合自由曲線的特性，我們適當修正速度預補償的定義，考慮到預補償的補償方向，經由電腦模擬加工得到不錯的精度，特別是修正後的速度預補償能夠在軌跡急速轉彎時，其輪廓誤差不至於有太大擴張。

In order to achieve the request of high precision and high feed-rate in the future, the Multi-axis Cross-Coupled Pre-compensation method (MCCPM) is developed in this study for compound five-axis machine tools. The machine is composed of 6DOF Stewart -platform and X-Y table, it has the advantage of precise location of the platform and X-Y table can offset the defect of insufficient workspace. The processed planning proposed can enlarge the application of CCPM, the interpolator proposed can effective to reduce the load of PC under process, and the application of free-form curve increase the processed capability of the machine. Besides, the orientation contour error and the orientation pre-compensation are defined in this study and let MCCPM can achieve the request for the precision of processed surface. Furthermore, we modify pre-compensation for the characteristic of free-form surface and consider the direction of compensation. It has great precision by PC simulations. Especially when the trajectory is quick to change direction, the contour error not has large variation.