目前線性編碼器廣泛應用於工業上，尤其在機械產業中更是利用線性編碼器達到精密定位控制之用。現今已有許多不同形式的線性編碼器如光學編碼器、雷射干涉儀、磁性編碼器等，然而磁性編碼器相較於光學線性編碼器，其優勢在於造價便宜、適合操作於有水、油脂和粉塵等嚴苛環境。在製作磁性線性編碼器過程中，磁性尺在捲收時會處於不同的彎曲半徑，而在捲料當下，殘留應力會在磁性尺當中逐漸累積。所以當鬆開時磁性尺表面會呈現殘留應力引起的彎曲變形。磁性尺的變形會影響磁場大小與磁通量密度大小使得磁性尺的充磁品質跟著改變。
本論文致力於研究與開發一種滾輪矯直整平機台，以用於磁性尺上來達到去除磁性尺殘留應力造成之彎曲的效果。可變式滾輪矯直整平機台能夠在不同的環境與操作參數下進行參數研究，如滾輪下壓量、大小、間距等。再以實驗的方式探討及進行參數的研究，以釐清如何將滾輪整平機最佳化、整合到磁性尺的製造，以改善彎曲撓度、消除殘餘應力。而最終也分析出滾輪整平系統在不同操作參數下的最佳表現。實驗結果證明滾輪整平系統可以明顯將磁性尺彎曲撓度降低將近60%。本研究以小變形理論與彈性力學理論來分析與驗證磁性尺因殘留應力引起的彎曲變形。

Magnetic linear encoder has been increasingly integrated in various position control application while demands for high precision machine tool to produce high precision products increase. Due to its advantage in withstanding unclean environment such as oil, grease, and dust over an optical encoder, a magnetic encoder has become a desirable choice for machine tools. During the manufacture of magnetic encoding medium, the medium is not expected to be flat due to packaging induced plastic deformation and residual stress. Medium deformation will result in damaging the performance of the medium such as the accuracy and magnetic flux density distribution.
In this paper, the research efforts are devoted to develop a roller leveling system to flatten the curved magnetic medium. Variable roller leveling system is designed and manufactured to perform parameter studies such as number of leveling and the indentation, diameter, and spacing of leveling rollers. Parameter studies are carried out to investigate how roller leveling can be integrated into the manufacture of magnetic encoding medium to improve mechanical deflection and residual stress. Optimal performance of the roller leveling system under specific parameter has been determined. Furthermore, experimental results demonstrate that roller leveling can significantly improve mechanical deflection of pre-stressed curve magnetic medium up to almost 60%. Residual deflection and residual stress of the deformed medium are validated through analytical studies using theory of Euler-Bernoulli beam and Elastica.

摘要
ABSTRACT
ACKNOWLEDGEMENT
LIST OF FIGURES
LIST OF TABLES
CHAPTER I. INTRODUCTION
1.1 Introduction
1.2 Current Magnetic Encoder Technology and Development
1.3 Motivation
1.4 Literature Review
1.4.1 Nine Roller Leveler
1.4.2 Fourteen Roller Leveler
1.4.3 Variable Roller Leveler
1.4.4 Integrated roller leveler
1.5 Objectives
CHAPTER II. INVESTIGATION ON EFFECT OF MEDIUM CURVATURE AND GAP DURING MAGNETIZATION
2.1 Introduction
2.2 Magnetizing Platform Model Setup
2.3 Simulation Measurement Method
2.4 Simulation Results Analysis
2.4.1 Curvature Variation
2.4.2 Gap Variation
2.4.3 Combined Variation
2.5 Chapter Conclusion
CHAPTER III. ROLLER LEVELING SYSTEM DESIGN AND MANUFACTURING
3.1 Principle of Roller Leveling
3.2 Roller Leveling Specimen Properties
3.2.1 Dimensions
3.2.2 Mechanical properties
3.3 Design and Manufacture of Roller Leveling System
3.3.1 Leveling Rollers
3.3.2 Adjustable Roller Platform
3.4 Chapter Conclusion
CHAPTER IV. EXPERIMENTAL SETUP AND MODEL
4.1 Experimental Measurement Setup and Methods
4.1.1 Deflection measurement setup and methods
4.1.2 Force measurement setup and methods
4.2 Initial Deflection Elastica Model
4.2.1 Deflection equivalent force
4.2.2 Medium bending stress
4.3 Chapter Conclusion
CHAPTER V. PARAMETER STUDIES OF ROLLER LEVELING SYSTEM
5.1 Deflection Parameter Studies
5.1.1 Number of leveling cycles
5.1.2 Roller indentation
5.1.3 Roller diameter
5.1.4 Roller spacing
5.2 Force Parameter Studies
5.2.1 Roller indentation
5.3 Chapter Conclusion
CHAPTER VI. CONCLUSION AND FUTURE WORK
6.1 Conclusion
6.2 Future work
REFERENCE

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