Development of a 3-Axis Fast Tool Servo with Low Interference Motions (III)

[[abstract]]近年來，隨著光學裝置的小型化和多功能化，元件形狀由軸對稱非球面進展為非軸 對稱之自由曲面；而且，具有大量微細溝槽之背光模組或繞射格子等的需求亦不斷增 加。對於這些非軸對稱形狀的模仁加工，必須先計算各個加工點以形成加工點群，工具 機才能依目標點群進行加工。這種方式，受限於原加工機台的速率，加工時間極為冗長， 因此，如何縮短加工時間，以避免環境變化或刀具劣化，為當前業界的重要課題。 有鑑於此，本研究提出「低干涉運動3軸向快速刀具伺服裝置之研發」以提升模仁 的加工效能。在三年計畫時程中，將建構新型刀具伺服裝置，且在四軸超精密加工機上 驗證性能。第一年度(101)的工作，已完成刀座的設計、分析，並試作實驗裝置，驗證其 靜態特性等。第二年度(102)的主要工作項目，在於驗證動態特性，並利用FPGA模組建 立即時控制系統，建構OPA放大迴路驅動壓電致動器，驗證系統控制特性。第三年度(103) 的目標，在於將快刀伺服裝置與原加工機進行系統整合，並進行加工實驗。首先，規劃 包含即時控制系統，可擷取光學尺信號並輸出控制指令，以達成刀具伺服功能。接著， 進行切削實驗，包含自由曲面、微溝槽、微鏡片陣列等，以確認成效。本研究計畫之執 行，預期將可提升國內在超精密加工領域的技術層次，並具學術研究與產業應用價值。[[abstract]]Due to performance progresses and miniaturized sizes of optical devices, features of optical components are with a trend from symmetric aspheric surface to asymmetric free form surface. In addition, the needs for such as back light modules and holograph elements featuring with massive micro grooves are increasingly presented recently. In the machining process of an asymmetric mold or die, uncountable points are grouped together for the tool to trace in sequence and to perform machining. This kind of machining requires huge time to operate since the travelling speed of a machine tool is restricted. Therefore, how to improve productivity and to avoid the effects caused by long-term operation during ultraprecision machining is an important issue in current industry. Therefore, a three axis fast tool servo (FTS) is proposed to improve the machining performance for molds and dies of optical components in this study. In this three years’ project, a newly designed FTS will be implemented, and the experimental examinations for the FTS mounted to a 4-axis CNC ultraprecision machining works will be performed. Currently, the first year’s (2012) works have being carried out. The design and analysis for the tool holder have been finished. The fundamental experiments are performed to examine steady characteristics of the FTS. In the second (2013) year’s works, to examinations the dynamic and control characteristics, the real-time control system is established by FPGA modules and the OPA circuit, which is used to actuate the PZT actuators. In the third (2014) year’s works, the FTS is installed to an existing ultraprecision machine for examining cutting performances. In the beginning, a real time control system is configured. The control system capable of acquiring the information of optical encoders and sending control commands to achieve tool servo function. In the next, machining experiments are performed for asymmetric free form surface, micro lens array, and micro grooves. Through these experimental examinations, the effectiveness of the project is verified. It is expected that the technology level in ultraprecision machining can be upgraded, and the research results are enriched with academic valuation and industrial applications, with the fulfillment of the proposal.[[note]]MOST103-2221-E327-02