Development of Full-Page Refreshable Tactile Display System

- 指導教授 黃漢邦 博士 研究生林明典

- Advisor :Dr. Han-Pang Huang Student :林明典

Lab. of Robotics., Department of Mechanical Engineering National Taiwan University Taiwan

Abstract:

The purpose of the research is to develop a full-page refreshable Braille display system for blind people. There are three parts in the research: mechanism design, design of driving circuit, and software design. Symbols, graphs or texts are converted to patterns or Braille by software. Then, the driving circuit receives the data by RS232 communication and actuates the electromagnets. Finally, blind people get graphs and Braille from full-page refreshable Braille display by touching the tactile rods.

 

In mechanism design, the electromagnets are used as the actuators. We propose a four-layer-overlapping structure in order to decrease the pitch of tactile display. Besides, the electromagnetic force is computed with Finite Element Analysis (FEA) by ANSOFT.

 

In design of driving circuit, row scan method is used in the control of full-page electromagnets. Furthermore, we use RS232 communication to receive the information from software.

 

        In software design, pattern module and Braille module are developed. The graphs can be converted into a dot-graph by pattern module. English and Chinese words are also transformed into Braille code by Braille module. The “regular expression” is applied in matching Braille rules. The English Braille rules, Chinese Braille rules are also built in the research. Finally, several modified methods are proposed to intensify the effect of Braille converting.



中文摘要:

本文之目的,是協助視障同胞建立一套盲人之圖文顯示系統。文中分為三大部分:即全頁點字觸摸顯示器的機構設計、驅動電路設計以及人機介面軟體之研發。圖文顯示的流程,是將目前顯示人機介面軟體的圖形或文字,經過轉換及資料傳輸,將資訊顯示在我們所發展的觸摸螢幕上,不但可以將中英文字、數字、標點符號和一些數學表示式,完整地呈現在我們設計的點字觸摸顯示器上,而且可以將符號及圖形轉成點圖讓視障同胞摸讀。因此視障同胞可以藉由觸摸上面的資訊來達到學習或是閱讀的目的,大大改進視障同胞先天上不利的條件。

 

在機構設計方面,我們使用電磁鐵作為突點的致動器,但是為要符合一般點字的點距規格,我們提出了四層交錯之機構擺置,以解決此問題。此外,針對電磁力的計算使用ANSOFT Finite Element Analysis (FEA),藉此來分析電磁力大小,以及電磁鐵之間的電磁力交互影響。

 

在驅動電路設計方面,我們使用列掃瞄方式對所有的電磁鐵做掃瞄控制,並且使用RS232介面做為我們的資料傳輸機制,接收從電腦的資訊,透過電流放大級驅動所有的電磁鐵。

在人機介面軟體方面,我們發展出圖形及點字的轉換模組。圖形模組可以將一般點陣圖轉換成為點圖,再送出至驅動電路。而點字轉換模組是利用regular expression 來做點字規則比對,建立中英文點字轉換表,可以將中英文字、數字、標點符號、甚至是中文破音字轉成點字,並且我們也針對點字轉換上做了強化,增加點字轉換的效率。