等切削力控制系統動態特性建立之研究

Identification of Cutting Dynamic Characteristic Systems for Constant Cutting Force Control

邱雅琳(Ya-Lin Chiou)

指導教授 ： 李貫銘

國立臺灣大學/工學院/機械工程學研究所/碩士(2017年)

https://doi.org/10.6342/NTU201702784

摘要

在過去數十年間工具機技術越來越成熟，在加工上應用越來越廣泛。傳統加工參數設定，通常以固定轉速或固定進給率進行加工，為避免造成刀具或機台損壞，在進給率的選擇上會以最嚴苛之條件進行設定，因此在加工時並非是最有效率的加工，而藉由適應性控制以變動進給率來維持等切削力進行加工，可以提高生產效率。
目前雖已有很多對適應性控制切削力的研究，但在建立動態系統的過程都較為複雜，通常沒有包含實際進行切削時的動態特性，故本研究是以較簡單的方法建立包含切削過程之動態系統為研究目的。除此之外，目前大部分的研究中量測切削力的訊號是使用動力計，但動力計價格昂貴且占空間，使加工受到諸多限制，故本研究擬利用主軸電流訊號取代動力計。
本研究建立切削時動態特性系統之方法為使用掃頻實驗的方式，對實驗中擷取的主軸電流訊號經過處理後進行系統鑑別來獲得代表此系統之轉移函數，透過此轉移函數設計一控制器並利用電流訊號進行等切削力控制之實驗驗證掃頻方式獲得切削動態系統的可行性。

關鍵字

等切削力 ； 掃頻實驗 ； 系統鑑別 ； 主軸電流

並列摘要

During past decades the techniques of computer numerical control (CNC) machining centers has grown tremendously and their applications has expanded rapidly. Traditionally the operating parameters such as spindle speed or feed rate are prescribed conservatively by experienced technicians in order to protect the cutting tool or the machine. As a result, many processes run under inefficient operating conditions. For this reason, using adaptive constant cutting force control with adjustable feed rate can improve efficiency.
Although there are already many researches for adaptive cutting force control, their methods of establishing dynamic systems are complicated and seldom take actual cutting dynamic characteristics of cutting process. The purpose of this study is to identifying cutting dynamics with consideration of actual cutting dynamic characteristics during cutting process in a simple way. Besides, most researches use dynamometer to measure cutting force, but dynamometer is expensive and limiting the working space. This study will use spindle current instead of cutting forces from dynamometer as input signals.
In this study, we establishes cutting dynamic characteristic system by using sweep experiment. By using system identification with spindle current data to get a transfer function of system, we can design a proper controller based on this transfer function and verify the feasibility of constant cutting force control with spindle current.

並列關鍵字

constant cutting force ； sweep experiment ； system identification ； spindle current ； adaptive control

參考文獻

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