本論文之目的在於討論中文點字觸摸顯示器之驅動器的設計與分析。點字驅動器在盲用中文顯示器是非常重要的元件，其作用是驅動點字桿向上達到點字凸出的效果，點字凸出的設計條件為點字桿必須提供最小向上15克的推力以及0.7 mm的凸出距離。本論文提出水平拍擊、垂直拍擊、垂直直驅、拴鎖電磁式驅動器、以及一種壓電式驅動器的可行設計。各種不同的驅動器依照其驅動特性，經由接觸力學分析、熱傳分析、電磁分析，以及壓電分析確保設計的可行性以及耐用性。
    電磁式驅動器經由適應性類神經模糊推論系統（ANFIS）執行設計參數預測分析，其目的為得到最小的驅動器溫升以及最大驅動力條件下的供應電壓以及線圈組抗。ANFIS亦用來設計壓電式驅動器，在特定的點字桿推力以及特定行程的條件下得到合適的供應電壓以及夾持位置。經由研究的結果發現，電磁式驅動器可經由改變驅動機構的方式達到充足的點字桿推力以及改善驅動線圈溫升的問題。電磁式驅動器因強健的驅動機構以及純熟的製作技術，確有長驅動壽命以及價格便宜的優點。經由設計的壓電式驅動器相對於電磁式驅動器有體積小、重量輕、無發熱量，以及低耗電量的優點。本研究的結果將可改善視障資訊輔具的功能，並提升視障者應用電腦的能力，使得視障者在就學、就業以及生活上得到實質的幫助。

This thesis discusses the design and analysis of actuators for Chinese Braille display (CBD). An actuator is the most important part to manipulate the Braille dot in Braille display. An effective convex Braille dot requires a thrust force at least 15 gf and must be of 0.7 mm in height. The actuators developed in this thesis include two types, electromagnetic actuators and piezoelectric actuator. The design includes four electromagnetic actuators, called horizontal flapper, vertical flapper, vertically direct actuating flapper, and latched mechanism flapper, and a piezoelectric actuator called PZT actuator. The numerical analysis, including contact mechanics, heat transfer, and electromagnetics, are applied in designing electromagnetic actuators, and the piezoelectric analysis is used in designing piezoelectric actuator to ensure the feasibility and durability of the design. 
The electromagnetic actuator is analyzed by Adaptive-Network-Based Fuzzy Inference System (ANFIS) to predict the design parameters, including supplied voltage and coil resistance, in order to obtain sufficient thrust force for Braille dots while maintaining flapper actuator’s temperature within limits. The ANFIS is also used to predict the piezoelectric actuator’s design parameters, including supplied voltage and clamped position, to obtain the sufficient thrust force and Braille dot height. The study shows the electromagnetic actuators can provide the sufficient thrust force and improve the temperature raise problem by using different actuating mechanisms. With the robust actuating mechanism and skillful manufacturing technology, the electromagnetic actuators have the advantages of long life span and low price. On the other hand, the piezoelectric actuator has the advantages of small size, light weight, no heat generation and low power consumption. The contribution of our investigation can improve the function of visually assistive device in information category and enhance the ability of visually impaired people (VIP) to use computer. With the maturity of CBD, the VIP can easily get education, job, and life assistance.

TABLE OF CONTENTS
CHINESE ABSTRACT	I
ENGLISH ABSTRACT	II
TABLE OF CONTENTS	IV
LIST OF FIGURES	VII
LIST OF TABLES	XI
LIST OF SYMBOLS	XIII
CHAPTER 1	INTRODUCTION	1
1.1	Motivation	1
1.2	Related Work	2
1.3	Overview of Chinese Braille Display	4
1.3.1	Electro-Mechanical Hardware	4
1.3.1.1	Interface Module	7
1.3.1.2	Logic Circuit Module	8
1.3.2	Assistive Software	9
1.3.2.1	Scheme of Human Computer Interface	10
1.3.2.2	Event Hooking Module	12
1.3.2.3	Braille Code Translator	12
1.3.2.4	ASCII Code Module	13
1.3.2.5	Mouse-Manipulating Module	16
1.3.2.6	Braille Code Output Module	18
1.4	Present Research	19
CHAPTER 2	BASIC DESIGN THEORIES	21
2.1	Mechanics Theory	21
2.2	Heat Transfer Theory	24
2.3	Electromagnetics Theory	25
2.4	Piezoelectric Theory	27
2.5	Adaptive-Network-Based Fuzzy Inference System	30
CHAPTER 3		DESIGN AND ANALYSIS OF BRAILLE ACTUATORS	34
3.1	Horizontal Flapper Braille Actuator	34
3.1.1	Mechanical Geometry Design	34
3.1.2	Mechanics Analysis	39
3.1.3	Thermal and Electromagnetics Analysis	42
3.2	Vertical Flapper Braille Actuator	46
3.2.1	Mechanical Geometry Design	46
3.2.2	Mechanics Analysis	49
3.2.3	Thermal and Electromagnetics Analysis	53
3.3	Vertically Direct Actuating Braille Actuator	55
3.3.1	Mechanical Geometry Design	55
3.3.2	Mechanics Analysis	57
3.3.3	Thermal and Electromagnetics Analysis	59
3.4	Latched Mechanism Braille Actuator	62
3.4.1	Mechanical Geometry Design	62
3.4.2	Mechanics Analysis	65
3.4.3	Electromagnetics Analysis	70
3.5	PZT Braille Actuator	72
3.5.1	Mechanical Geometry Design	72
3.5.2	Piezoelectric Analysis	73
CHAPTER 4		ANFIS PREDICTION FOR THE DESIGN PARAMETERS	76
4.1	ANFIS Prediction	76
4.1.1	Horizontal Flapper Braille Actuator	76
4.1.2	Vertical Flapper Braille Actuator	81
4.1.3	Vertically Direct Actuating Braille Actuator	84
4.1.4	Latched Mechanism Braille Actuator	88
4.1.5	PZT Braille Actuator	91
4.2	Results	94
4.2.1	Horizontal Flapper Braille Actuator	94
4.2.2	Vertical Flapper Braille Actuator	98
4.2.3	Vertically Direct Actuating Braille Actuator	101
4.2.4	Latched Mechanism Braille Actuator	103
4.2.5	PZT Braille Actuator	104
4.2.6	Discussions	105
CHAPTER 5	CONCLUSION	110
5.1	Conclusions	110
5.2	Future Work	112
REFERENCE	113
APPENDIX A	116

LIST OF FIGURES
Figure 1.1.	Braille codes and the standard Chinese Braille cell.	2
Figure 1.2.	Braille cells in Chinese Braille display and a keyboard.	6
Figure 1.3.	Schematic diagram of electronic design in CBD.	7
Figure 1.4.	PCB of interface module with USB and COM port.	8
Figure 1.5.	Schematic diagram of logic circuit module for decoding the actuation signals.	9
Figure 1.6.	The architecture of assistive software.	12
Figure 1.7.	Schematic diagram of Braille Code Translator.	13
Figure 1.8.	The position of Braille dots in each cell with corresponding keys and the numeric keypad for operating the guide mouse function.	15
Figure 1.9.	A homonym case of two Chinese words.	16
Figure 1.10.	Operation of guide mouse.	18
Figure 1.11.	Schematic diagram of constructing and designing an effective human computer interface for visually impaired people.	20
Figure 2.1.	Principle of the magnetic field production.	25
Figure 2.2.	Piezoelectric and converse piezoelectric effect.	28
Figure 2.3.	Piezoelectric axis and action for d31 mode.	30
Figure 2.4.	The architecture of ANFIS.	31
Figure 3.1.	Parts of flapper type actuator used in HFBD.	35
Figure 3.2.	Flapper actuators and Braille cell mechanism of HFBD.	37
Figure 3.3.	Computer designed Horizontal Flapper Braille cell module.	38
Figure 3.4.	Prototype of a HFBD Braille cell module.	38
Figure 3.5.	FEM mesh and the location of concentrated stress in A type armature of HFBD.	40
Figure 3.6.	FEM mesh and the location of concentrated stress in A type Braille pin of HFBD.	41
Figure 3.7.	FDM mesh and the complete arrangement of flappers in HFBD.	43
Figure 3.8.	The electromagnetic model of flapper in HFBD.	44
Figure 3.9.	Results of thermal and electromagnetic analysis of HFBD under nature and force convection.	45
Figure 3.10.	The flapper’s actuating mechanism and structure in VFBD.	47
Figure 3.11.	The Braille cell module of VFBD.	48
Figure 3.12.	The prototype of Braille cell module in VFBD.	48
Figure 3.13.	FEM mesh of a VFBD’s flapper.	50
Figure 3.14.	The result of displacement for VFBD’s flapper assembly.	50
Figure 3.15.	The result of stress distribution in VFBD’s flapper assembly.	51
Figure 3.16.	The result of strain analysis for VFBD’s flapper assembly.	51
Figure 3.17.	The process of the numerical solutions.	53
Figure 3.18.	The FDM mesh and complete arrangement of flappers in VFBD.	54
Figure 3.19.	The two dimensional magnetic flux field of the VFBD flapper actuator.	54
Figure 3.20.	Parts of flapper actuator of VDABD.	56
Figure 3.21.	Actuating mechanism of a Braille cell of VDABD.	56
Figure 3.22.	Computer designed Braille cell module of VDABD.	57
Figure 3.23.	Displacement of VDABD’s A type flapper mechanism.	58
Figure 3.24.	Von Mises stress of VDABD’s A type flapper mechanism.	58
Figure 3.25.	Equivalent strain of VDABD’s A type flapper mechanism.	59
Figure 3.26.	Thermal analysis of VDABD’s flapper in nature convection.	60
Figure 3.27.	Magnetic flux density of VDABD’s flapper actuator.	61
Figure 3.28.	Numerical results of VDABD’s thrust force and temperature.	61
Figure 3.29.	Schematic of initial and final attracting force.	62
Figure 3.30.	Detailed actuating mechanism of the paired flappers for LMBD.	63
Figure 3.31.	Flat and convex mode of a Braille dot mechanism for LMBD.	64
Figure 3.32.	Computer designed Braille cell module of LMBD.	64
Figure 3.33.	FEM mesh for latched mechanism of LMBD.	65
Figure 3.34.	Von Mises stress of LMBD’s latched mechanism.	66
Figure 3.35.	Equivalent strain of LMBD’s latched mechanism.	66
Figure 3.36.	Safety factor of LMBD’s latched mechanism.	67
Figure 3.37.	Detailed view of minimum safety factor occurring on the rivet joint.	67
Figure 3.38.	Shape design of a swing arm.	68
Figure 3.39.	Numerical results of minimum safety factor on swing arm and rivet joint of polymer frame.	70
Figure 3.40.	Magnetic flux density of LMBD’s flapper actuator.	71
Figure 3.41.	Magnetic flux intensity of LMBD’s flapper actuator.	71
Figure 3.42.	The assembly of eight PZT actuators and Braille pins.	73
Figure 3.43.	Computer designed PZT Braille cell module.	73
Figure 3.44.	Actuating principle of a PZT actuator to drive a Braille pin.	74
Figure 3.45.	Numerical results of thrust force and stroke for PZT actuator.	75
Figure 4.1.	Initial and final MFs for HFBD.	77
Figure 4.2.	RMSE and step size for maximum temperature and supplied voltage of HFBD.	78
Figure 4.3.	ANFIS reasoning under nature and force convection for HFBD.	79
Figure 4.4.	The structure of enameled coil wound on the iron core.	80
Figure 4.5.	The learning procedure and reasoning system of ANFIS.	82
Figure 4.6.	Initial and final MFs for VFBD.	83
Figure 4.7.	RMSE and step size for maximum temperature and supplied voltage of VFBD.	84
Figure 4.8.	Initial and final MFs for VDABD.	86
Figure 4.9.	Training data, ANFIS output, RMSE, and step size of VDABD.	87
Figure 4.10.	Initial and final MFs for LMBD.	89
Figure 4.11.	Training data, ANFIS output, RMSE, and step size of LMBD.	90
Figure 4.12.	Initial and final MFs for PZTBD.	92
Figure 4.13.	Training data, ANFIS output, RMSE, and step size of PZTBD.	93
Figure 4.14.	Comparison of maximum temperature and supplied voltage of HFBD analyzed by numerical models and predicted from ANFIS (330 Ω).	95
Figure 4.15.	Numerical results for HFBD by the supplied voltage predicted from ANFIS (330 Ω) in nature convection.	97
Figure 4.16.	Temperature measured from HFBD’s 45 Braille cells.	98
Figure 4.17.	Computer designed Horizontal Flapper Braille display.	106
Figure 4.18.	Computer designed Vertical Flapper Braille display.	106
Figure 4.19.	Computer designed Vertically Direct Actuating Braille display.	107
Figure 4.20.	Computer designed Latched Mechanism Braille display.	107
Figure 4.21.	Computer designed PZT Braille display.	108

LIST OF TABLES
Table 1.1.	Function keys of guide mouse.	17
Table 3.1.	Statistical mechanics results of A and B type armature in HFBD.	41
Table 3.2.	Statistical mechanics results of A, B, C, and D type Braille pin in HFBD.	42
Table 3.3.	Numerical results of a Horizontal Flapper Braille cell module (330 Ω).	46
Table 3.4.	Statistical mechanics results of A, B, C, and D type Braille mechanism in VFBD.	52
Table 3.5.	Statistical mechanics results of flapper mechanism in VDABD.	59
Table 3.6.	Statistical mechanics results of mechanics analysis with various shape of swing arm.	69
Table 3.7.	Thrust force of flapper in initial and final status (165 Ω) for LMBD.	72
Table 4.1.	The thickness of HFBD’s flapper to each coil resistance.	94
Table 4.2.	Comparison of maximum temperature and supplied voltage analyzed by numerical models and predicted from ANFIS for HFBD.	95
Table 4.3.	The HFBD’s numerical results in nature convection for supplied voltage predicted by ANFIS in force convection.	97
Table 4.4.	Numerical, experimental, and ANFIS Results for HFBD.	98
Table 4.5.	The thickness of VFBD’s flapper to each coil resistance.	99
Table 4.6.	The feasible design solutions of VFBD.	100
Table 4.7.	Comparison of the numerical model, ANFIS, and experimental results of VFBD.	101
Table 4.8.	The thickness of VDABD’s flapper to each coil resistance.	102
Table 4.9.	ANFIS predictions for the feasible design in VDABD.	103
Table 4.10.	ANFIS predictions for the feasible design in LMBD.	104
Table 4.11.	ANFIS predictions for the feasible design in PZTBD.	105
Table 4.12.	Specification of blowers used in HFBD and VFBD.	107
Table 4.13.	Comparison of feasible design of five actuators without blower.	109

[1]	P. Brunet, B. A. Feigenbaum, K. Harris, C. Laws, R. Schwerdtfeger, and L. Weiss, “Accessibility Requirements for Systems Design to Accommodate Users with Vision Impairments,” IBM Systems Journal, Vol. 44, No. 3, pp. 445-467, 2005.
[2]	D. Blazie, “Refreshable Braille Now and in the Years Ahead,” Braille Monitor, Vol. 43, No. 1, 2000. Available from:
	http://www.nfb.org/Images/nfb/Publications/bm/bm00/bm0001/bm000110.htm
[3]	N. Sriskanthan, and K.R. Subramanian, “Braille Display Terminal for Personal Computers,” IEEE Trans. Consumer Electron, Vol. 36, No. 2, pp. 121-128, 1990.
[4]	A. Basu, P. Dutta, S. Roy, and S. Banerjee, “A PC-Based Braille Library System for the Sightless,” IEEE Trans Rehabil Eng., Vol. 16, No. 1, pp. 60-65, 1998.
[5]	S.F. Frisken-Gibson, P. Bach-Y-Rita, W.J. Tompkins, and J.G. Webster, “A 64-solenoid, Four-Level Fingertip Search Display for the Blind,” IEEE Trans. Biom. Eng., BME-34 No.12, pp. 963-965, 1987.
[6]	J. Roberts, O. Slattery, D. Kardos, and B. Swope, “New Technology Enables Many-Fold Reduction in the Cost of Refreshable Braille Displays,” Fourth Annual ACM Conference on Assistive Technologies, Virginia, USA, pp. 42-49, 2000.
[7]	Y. Haga, W. Makishi, K. Iwami, K. Totsu, K. Nakamura, and M. Esashi, “Dynamic Braille Display Using SMA Coil Actuator and Magnetic Latch,” Sens. Actuators A, Vol. 119, pp. 316-322, 2005.
[8]	P.S. Wellman, W.J. Peine, and R.D. Howe, “Mechanical Design and Control of A High-Bandwidth Shape Memory Alloy Tactile Display,” International Symposium of Experimental Robotics, Barcelona, Spain, pp. 55-66, 1997.
[9]	P.M. Taylor, A. Moser, and A. Creed, “A Sixty-Four Element Tactile Display Using Shape Memory Alloy Wires,” Displays, Vol. 18, pp. 163-168, 1998.
[10]	P.M. Taylor, D.M. Pollet, A. Hosseini-Sianaki, and C.J. Varley, “Advances in An Electrorheological Fluid Based Tactile Array,” Displays, Vol. 18, pp. 135-141, 1998.
[11]	L. Yobas, M. Huff, F. Lisy, and D.M. Durand, “A Novel Bulk-Micromachined Electrostatic Microvalve with A Curved-Compliant Structure Applicable for A Pneumatic Tactile Display,” J. Microelectromech. Syst., Vol. 10, pp. 187-196, 2001.
[12]	L. Yobas, D.M. Durand, G.G. Skebe, F.J. Lisy, and M.A. Huff, “A Novel Integrable Microvalve for Refreshable Braille Display System,” J. Micro-electromech. Syst., Vol. 12, pp. 252-263, 2003.
[13]	C. Ramstein, “Combining Haptic and Braille Technologies: Design Issues and Pilot Study,” Second Annual ACM Conference on Assistive Technologies, British Columbia, Canada, pp. 37-44, 1996.
[14]	F.R. Adams, H. Crepy, D. Jameson, and J. Thatcher, “IBM Products for Persons with Disabilities,” IEEE Proceedings Global Telecommunications Conference, Vol. 2, IEEE Press: Dallas, TX, pp. 980-984, 1989.
[15]	T. Watanabe, S. Okada, and T. Ifukube, “Development of A GUI Screen Reader for Blind Persons,” IEICE Transactions J81- D-II, No. 1, pp. 137-145, 1998.
[16]	R.W.P. Luk, D.S. Yeung, Q. Lu, H.L. Leung, S.Y. Li, and F. Leung, “ASAB: A Chinese Screen Reader,” Softw. Pract. Exper, Vol. 33, No. 3, pp. 201-219, 2003.
[17]	H. Guckel, T. Earles, J. Klein, J.D. Zook, and T. Ohnstein, “Electromagnetic Linear Actuator with Inductive Position Sensing,” Sensors and Actuators A, Vol. 53, pp. 386-391, 1996.
[18]	K.J. Bathe, Finite Element Procedures, Prentice-Hall, New Jersey, 1996.
[19]	S.V. Patankar, Numerical Heat Transfer and Fluid Flow, Hemisphere, New York, 1980.
[20]	M. Plonus, Applied Electromagnetics, McGraw-Hill, New York, 1978.
[21]	A. Preumount, Mechatronics: Dynamics of Electromechanical and Piezoelectric Systems, Springer, Netherlands, 2006.
[22]	A.H. Meitzler, H.F. Tiersten, A.W. Warner, D. Berlincourt, G.A. Coquin and F.S. Welsh, An American National Standard: IEEE Standard on Piezoelectricity, ANSI/IEEE Std 176-1978, New York, 1987.
[23]	J.-S.R. Jang, and C.-T. Sun, “Neuro-Fuzzy Modeling and Control,” Proceedings of IEEE, Vol. 83, pp. 378-406, 1995.
[24]	J.-S.R. Jang, “ANFIS: Adaptive-Network-Based Fuzzy Inference Systems,” IEEE Trans. Syst. Man, Cybernet., Vol. 23, pp. 665-685, 1993.