February 18, 2008 - School of Engineering Science
Contents
1. CBA Canadian Braille Authority RNIB Royal National Institute of the Blind located in the United Kingdom CSA Canadian Standards Association Grade I Braille Braille output is letter by letter small words are spelled out entirely Grade II Braille Form of Braille shorthand single characters represent whole words ANSI American National Standards Institute OCR Optical Character Recognition interpretation of an image to extract text 2008 BDot Page iv BDot School of Engineering Science Simon Fraser University t 8888 University Drive Burnaby BC V5A 1S6 ensc440 braille sfu ca 1 0 Introduction BDot s revolutionary system Tiresias is a portable cost effective Braille display for the visually impaired By using compressible pins in sets of six ASCII characters will be read in and translated into a corresponding Braille character By using an innovative refreshing system these characters can be reset to allow for continuous and seamless translation of digital information for the visually impaired Small and lightweight it can be used everywhere giving the visually impaired the freedom every Canadian deserves This document proposes BDot s specifications for the functionality of the device The requirements for each aspect of the device is analyzed in detail with emphasis on portability and usability By the completion of this project we hope to have accomplished all the functional goals enumerated in this documen2. shall incorporate the following e Allow for character output bi directionally left to right or right to left e A wrist or palm support to facilitate the proper ergonomic placement of the wrist e Buttons the user can use to navigate menus go forwards or backwards in the text and refresh the display 3 1 General Requirements D1 II The display shall refresh to advance to the next line D2 II The display shall be refreshed automatically or be refreshed manually by the user D3 II The display shall be able to represent at least ten characters at once D4 II The dots shall be raised a minimum of 0 81 mm above the surface of the display 3 3 2 Physical Requirements D5 II The display length shall be at minimum 11 cm and at maximum 15 cm D6 II The display height shall be at minimum 2 cm and at maximum 8 cm at its highest point D7 II The display shall feel smooth and level upon contact when there are no characters displayed D8 II The dots shall be hemispherical to conform to Braille tactile standards 3 3 Mechanical Requirements D9 II The display refresh shall have a response time of less than 3 seconds D10 II The device shall be fully controllable by the user 3 4 Standards D11 II The display shall correspond to standards as stated by the UEB code 1 D12 II The display shall correspond to standards as stated by the CBA 2 D13 II The Braille characters cells shall conform to the En
3. 4 II The device shall turn off after 10 minutes without use to conserve power 2 5 Mechanical Requirements S15 II The device shall begin operation in a rest state with no characters displayed S16 II The device must provide a means to form Braille characters on the display S17 II The device must be able to revert back to a rest state reset 2 6 Environmental Requirements S18 II The device shall perform under normal ranges of humidity for electronic devices S19 II The device shall perform at altitudes between 0 and 2000 m above sea level S20 II The device shall operate with sound at less than 20 dB S21 II The device shall operate at temperatures between 10 and 50 degrees Celsius 2 7 Standards S22 II The device shall conform to ANSI standards S23 II The device shall meet all appropriate CSA requirements 2 8 Reliability and Durability S24 II The device shall be able to withstand daily use without failure S25 II The lifetime of the device before maintenance shall be no less than 2000 hours S26 III The device shall be resistant to water and other liquids S27 III The device shall withstand reasonable abuse from the user tactile pressure 2 9 Safety Requirements S28 II The electrical and mechanical components of the device shall be enclosed and inaccessible by the user S29 II The device shall be easily serviceable by trained technicians S30 II The device shall not shock
4. BDot School of Engineering Science Simon Fraser University t 8888 University Drive Burnaby BC V5A 1S6 ensc440 braille sfu ca February 18 2008 Patrick Leung P Eng School of Engineering Science Simon Fraser University Burnaby British Columbia V5A 156 RE ENSC 440 Project Functional Specifications for Portable Braille Display Dear Mr Leung Please find enclosed the functional specifications for a small cost effective portable device for storing and displaying Braille The end objective of this project is a unit which will give individuals with visual impairments the ability to read material in a portable manner The compact style of design will allow it to be used ubiquitously and its ability to refresh will allow individuals to take large amounts of reading material without considerable bulk The objective is to take digital content or content converted to digital and display it in Braille This document aims to outline the functionality of the unit without going into further detail about the specific design It will give a broad overview of what the unit shall do in terms of specific high level requirements and give constraints with which the device should be created under These requirements will be outlined for both the proof of concept and production phases The BDot team is comprised of five innovative and passionate engineering students who see the technology as an opportunity to make manifest a future where techn
5. e complete by April 17 2008 at which time a functional prototype will be available This prototype shall conform to all applicable safety and design standards including CSA and UEB regulations Furthermore in Phase II it shall then be possible to expand the current device to conform to other Braille cell specifications as well as be produced in an even more compact manner BDot does not see the world as it is but what it could be imagining a world where blind people can be a part of the global workforce of the new millennium Tiresias has the power to change the face of assistive technology in a groundbreaking way 2008 BDot Page ii BDot School of Engineering Science Simon Fraser University t 8888 University Drive Burnaby BC V5A 1S6 ensc440 braille sfu ca Table of Contents Executive EE ii Tableof Hee iii Fist EE iv GLOSSY tee iv FAKE y cassissseciasnsncsascnancddasydntiuesnanecannsaoesesdedaccaaundaseibshaactanvasienaaipaaddeeintaceeasiaancamianraagsaenans 1 UK 1 1 2 Jntended EE 1 1 3 Classificati ON TE 1 2 0 System FRUIT STINE ecreis ieira ee 2 2 1 System deene idee nde 2 2 2 General EN E 5 2 3 Physical RER sisse nsniinr a i E EAE ee 5 2 4 Electrical Requirements occisccaseustereneaansaesceeheccannseeevsensdineeeaeaausnensdacencedansersatbecusnapraaveatsaroneuiees 6 2 5 Mechanical RECUITeWIC ING z sessctccsecheesitsdneseseewinessexbenecunnde TE E E AEE ENTER ENESTE 6 2 6 Environmental KGquinciments is jccicssisaccsia
6. e equivalents the display could simply perform a letter to letter mapping This is commonly called Grade I Braille However with the English language having a great deal of repetitive words and you so etc single Braille characters are often used as a shorthand This second format constitutes Grade II Braille Our display will give the user the option of outputting the characters in both Grade I and Grade II Braille depending on their preference The Braille output will conform to English Giant Dot size specifications as outlined by the RNIB 3 and illustrated in Figure 3 2008 BDot Page 3 BDot School of Engineering Science Simon Fraser University t 8888 University Drive Burnaby BC V5A 1S6 ensc440 braille sfu ca Figure 3 English Giant Dot Braille size constraints mm The device will be designed such that a visually impaired person can use it without additional aid Braille characters will be output mechanically depending on the incoming digital content and the user will be able to adjust the refresh rate for the next line of text depending on their reading speed For added convenience the user will also be able to manually advance the display to the next line of content All device configurations will be found on the display itself as opposed to on an interfacing computer A diagram of general connectivity is provided in Figure 4 Note that the portable power source is represented by a battery and removable memo
7. ents are expected to be met by the end of the design cycle and production requirements will be easily implementable after that point 2008 BDot Page 11 BDot School of Engineering Science Simon Fraser University t 8888 University Drive Burnaby BC V5A 1S6 ensc440 braille sfu ca 7 0 References 1 Unified English Braille International Council of English Braille ICEB http www iceb org ueb html 2 Canadian Braille Association CBA http www canadianbrailleauthority ca index php 3 Royal National Institute of the Blind Scientific Research Unit SRU http www tiresias org publications reports braille_cell htm 4 What is Braille American Foundation for the Blind http www afb org Canadian Standards Association http www csa ca American National Standards Institute http www ansi org 2008 BDot Page 12
8. glish Giant Dot format as outlined by the RNIB 3 2008 BDot Page 8 BDot School of Engineering Science Simon Fraser University t 8888 University Drive Burnaby BC V5A 1S6 ensc440 braille sfu ca D14 II The characters shall be displayed in both Grade I and Grade II Braille 4 as defined by user ability 3 5 Usability Requirements D15 II The user shall be able to easily identify different Braille characters on the display D16 II The user shall be able to set all options directly from the device D17 III The display shall indicate to the user changes in the system by means of haptic feedback 3 6 Safety Requirements D18 II The display shall not harm the user when refreshing D19 II The display shall not emit any heat or otherwise uncomfortable sensations 4 0 Device User Interface The device shall be user controlled for bi directionally movement through text Figure 5 below shows an overview of user control gt 5 minutes fwd rwd gt 10 minutes Figure 5 Flowchart of user control 4 1 General Requirements U1 II The controls shall be logically configured so as to invoke appropriate actions from the user U2 II The controls shall be labeled in both Braille and English U3 II The device shall have a set of controls that shall be able to play pause stop fast forward rewind power on and power off the system 2008 BDot Page 9 BDot School of Engineering Science Simon Fra
9. n this digital age content is often in an electronic format or has the ability to be converted thusly Even with digital content being more accessible than ever the visually impaired are still hindered from fully accessing this information Tiresias is a solution to this obstacle Displays currently on the market are simply not cost effective costing thousands of dollars the average person simply cannot afford them Furthermore being large and cumbersome they are certainly not portable in any viable sense The visually impaired need a display that they can use on their own a device that excels in efficiency ease of use and is chiefly portable They need Tiresias The development cycle will be split into two phases a proof of concept phase and a production phase Generally the only differences between these phases will be the ability to mass produce the display in the production phase As well due to the extremely small nature of Braille cells the prototype completed in the proof of concept phase may be slightly larger than specifications Upon completion of Phase I the display will e Display characters in Grade I or Grade II Braille e Becompatible with users of either handedness e Allow for change in direction of character outputs e Refresh as soon as the user requests e Be able to accept digital media of various types for translation e Store a bookmark of the last read page if the display turns off Phase I is expected to b
10. nts work or school related into Braille using Tiresias Auditory feedback is also crucial to this stage since the visually impaired will require cues to give them confirmation of changes 5 1 General Requirements C1 II The device shall be able to communicate with a PC C2 II The device shall be able to transfer data from a PC 5 2 Usability Requirements C3 II The mode of connection between the device and computer shall be customized for the target audience C4 I The device shall interface with computers running the Windows XP operating system 2008 BDot Page 10 BDot School of Engineering Science Simon Fraser University t 8888 University Drive Burnaby BC V5A 1S6 ensc440 braille sfu ca C5 II The device shall interface with computers running the Windows XP Vista and Mac OS C6 II The computer interface shall provide auditory feedback to alert the user of changes in operation 5 3 Software Requirements C7 II The software shall convert text into ASCII characters on demand C8 II The software shall incorporate OCR technology to convert textual content into digital form 6 0 Conclusion The functionality coupled with the portability of this device makes it a viable product for the market By conforming to all of the latest mechanical electrical and Braille standards it is a cutting edge device that offers unparalleled performance convenience and functionality All functional requirem
11. nts for the Tiresias Braille Display unit as envisioned by BDot 2 1 System Overview In Figure 2 the system concept is shown in terms of a high level flowchart Each stage of the display from input to output is summarized 2008 BDot Page 2 BDot School of Engineering Science Simon Fraser University t 8888 University Drive Burnaby BC V5A 1S6 ensc440 braille sfu ca Input Output Refresh Digital content into Tiresias Braille display Refresh dots to Ulli Mechanical from ASCII S processing prepare for next line to Braille I to output or Il dots Figure 2 High Level Functional Diagram The primary goal of Tiresias is to translate digital content into Braille characters for the visually impaired Content will be translated into ASCII characters and stored in some form of removable non volatile memory accessible by the display When the device is in use this content will be processed and a mechanical output will convert the data into Braille Each ASCII character or word depending on the output type will correspond to one Braille cell on the display The dots in a cell will be mechanically raised or dropped to represent the Braille form of that character The user will also have the option of going back to previous read lines The cells will be refreshed to represent the next line of text There are two common ways of interpreting Braille from ASCII Since most ASCII characters are easily mapped to Braill
12. of concept device shall be available in English for use with the device S45 IN Documentation for the production device shall be available in English and French and in Braille formats S46 II All documentation will explain the functionality of the device S47 III A troubleshooting manual shall be provided for users and or trained technicians S48 III Multi language versions of documentation shall be made available on the website 2 14 Compatibility Requirements S49 I The device shall interface with a PC S50 II The production device shall interface with both PC and Mac computers SS1 II The system shall require the use of a standard I O port on the computer to interface with the device 2 15 Luxury Functions S52 III The device shall include a voice chip to provide auditory feedback S53 III The device shall include a microphone for voice recognition commands 2008 BDot Page 7 BDot School of Engineering Science Simon Fraser University t 8888 University Drive Burnaby BC V5A 1S6 ensc440 braille sfu ca 3 0 Display The display is the most important component since it is the area the user will interact with most and the main function of the device Both the construction and functionality of the display are important things to consider The display creates raised Braille characters using a series of six dots per character for the user to read using the tips of his her fingers The device display
13. ology allows our society to reach its full potential As engineers it is our professional and ethical obligation to contribute not only in technical ways but to apply our knowledge to alleviate the problems in our society as well We are Jill Steele CMO Joan Thomas CFO Mei Young COO Dave MacLeod CTO and myself Jessica Tang CEO If any questions concerns or problems should arise please feel free to contact us at ensc440 braille sfu ca Sincerely A oil MS ntl s T Jessica Tang BDot Chief Executive Officer Enclosure Functional Specifications for a Portable Braille Display cc Steve Whitmore Bradley Oldham Jason Lee E Boot SEEING THE WORLD AS IT COULD BE Tiresias Portable Braille Display FUNCTIONAL SPECIFICATIONS Management Team Contact Submitted To Revision Date Revision Number Dave MacLeod Jill Steele Jessica Tang Joan Thomas Mei Young ensc440 braille sfu ca Patrick Leung Steve Whitmore Bradley Oldham Jason Lee January 21 2008 1 0 BDot School of Engineering Science Simon Fraser University t 8888 University Drive Burnaby BC V5A 1S6 ensc440 braille sfu ca Executive Summary The visually impaired are clearly lacking an important tool for coping with their disability a truly mobile Braille display Having access to a cost effective display of this form would undoubtedly increase their productivity independence and contributions to society However i
14. rsexassasanccannnsdeciansasccteainabassalaccamnsnaupianccatamabasauns 6 E 6 2 8 Reliability LDU EE 6 2 9 Safety e EE 6 2 10 Performance Requirements ccnsscsniceeautsanncessawanudastestucvan ye egene 7 SANEM T 2 13 Documentation amp User Manual Requirement 00 0 0 ccccecceeeeecceeceeeseceeeeeeeeeseecsseeneenees 7 2 14 Compatibility EE EE 7 2 15 Ee 7 IO DISpla y eege 8 REN EE 8 3 2 Physical ent 8 EE EE 8 E EE 8 3 5 Usability DEIER eege eddi H ER EEN H 4 0 Device User ee 9 4 1 General quar E E 9 4 2 Usability Retter E EAEE E E E EARR 10 4 3 Physical Requirements amp cacvpususxasdtuennannguasengeasennctaneesoatincesanmcacaseupeavenscntnees enreasunnneaquiventianrnnaess 10 50 Comp ter User Iie race isrscian nna A E A EE O 10 5 1 General RCT CIS EE 10 2008 BDot Page iii BDot School of Engineering Science Simon Fraser University t 8888 University Drive Burnaby BC V5A 1S6 ensc440 braille sfu ca 5 2 Usability TEE 10 5 3 Software IR SQUILCTICI IS serrrsisekriae isegi arei EE Ei aoa S EENE KTE EEEE 11 6 0 WE noe iae aE E E EEEE EE EE RETE Ea EAA EERS 11 Zeene EEE EEEE O EEEE EE 12 List of Figures Fig re ds Numbers e EE 2 Figure 2 High Level Functional Tests ec 3 Figure 3 English Giant Dot Braille size constraints mm 4 Figure 4 Visualization of system ConpecChvity ec ceeceeeeesceesceceseceseceeeeeeseecsaeceseeseaeeeseecsaeenseeees 5 Figure 5 Flowchart tee E 9 Glossary UEB Unified English Braille Code
15. ry by an SD card These images are simply for clarification and visualization and are not implicative of our design choices 2008 BDot Page 4 BDot School of Engineering Science Simon Fraser University t 8888 University Drive Burnaby BC V5A 1S6 ensc440 braille sfu ca Figure 4 Visualization of system connectivity 2 2 General Requirements S1 I The retail cost of the system shall not exceed 1000 S2 II The system shall be portable S3 II The system display shall be refreshable S4 I The device shall be able to store the textual data of a standard e book 2 3 Physical Requirements S5 II The base of the device shall not exceed 15 cm S6 II The height of the device shall not exceed 6 cm S7 I The width of the device shall not exceed 10 cm S8 II The weight of the device shall not exceed 400 g S9 II The device shall provide adequate wrist support for the user S10 II The device shall be shaped such that it is stored easily and comfortably 2008 BDot Page 5 BDot School of Engineering Science Simon Fraser University t 8888 University Drive Burnaby BC V5A 1S6 ensc440 braille sfu ca 2 4 Electrical Requirements S11 II The device shall be powered by a portable power source S12 II The portable power source shall be rechargeable and reliable S13 II The portable power source shall provide at least 3 hours of continual use before requiring to be re charged S1
16. ser University t 8888 University Drive Burnaby BC V5A 1S6 ensc440 braille sfu ca 4 2 Usability Requirement U4 II The device shall have an off state where no power is being consumed U5 II The device shall have a clear state where no characters are displayed and pointer is moved back to the start of file U6 II The device shall have a run state where characters are continuously being displayed U7 II The device shall have a wait state where the display is frozen for at most 5 minutes U8 II The device shall enter clear state if the device has been in wait state for more than 5 minutes U9 II The device shall enter off state if the device has been in clear state for more than 10 minutes U10 II The device shall be able to fast forward and rewind the display character one line at a time 4 3 Physical Requirements U11 II The control panel shall be placed such that the palm wrist and arm will not interfere with its use or be activated unintentionally U12 II The user controls shall be large enough for ease of use of the target audience 5 0 Computer User Interface While the device is standalone as far as mechanical function goes it will require the use of a computer to transfer digital content converted to the device Most digital content is found online so it is important that the device can integrate flawlessly with a computer This will also give the user the ability to translate their own docume
17. t 1 1 Scope The functional specifications laid out in this document describe in detail the requirements for the prototype device It also expands on the functionality of the final production model These specifications will be used to asses if the goals of this project have been met in terms of usability for our target market 1 2 Intended Audience This document will be used by the BDot engineering team to track the advancement of Tiresias from the conceptual stage through the prototyping phase to the production stage It will be used by usability engineers and ergonomists to ensure the device can be conveniently used by the visually impaired 1 3 Classification The numbering convention used through the document is of the form Xn s Where X represents the document section represents the requirement number and s represents the stage of development Figure lists the values that these elements are constrained to 2008 BDot Page 1 BDot School of Engineering Science Simon Fraser University t 8888 University Drive Burnaby BC V5A 1S6 ensc440 braille sfu ca s stage of development n requirement X Section warner l only in prototype System Overview Il in prototype and production model D Display II only in production model C Computer Interface U User Interface Figure 1 Numbering Convention 2 0 System Requirements The following section outlines the general requireme
18. the user S31 II The device shall not hurt the user by pinching or poking while the device is refreshing 2008 BDot Page 6 BDot School of Engineering Science Simon Fraser University t 8888 University Drive Burnaby BC V5A 1S6 ensc440 braille sfu ca S32 III The device shall be able to detect improper use notify the user and shut down the device 2 10 Performance Requirements S33 III The device shall bookmark the last read document location S34 II The device shall ensure all dots are raised uniformly for each character S35 II The device shall ensure all dots are raised synchronously for each character 2 11 Usability Requirements S36 II The device shall be ergonomic and usable by a person of either handedness S37 II The device shall include non slip surface to facilitate a comfortable grasp S38 II A single line shall be defined as ten characters in length S39 II The device shall allow the user to manually advance in the displayed document S40 II The device shall incorporate Braille specialized characters such as accented letters S41 II The user shall not require another individual to aid them in using this device S42 II All device settings shall be located on the device itself and be easily accessible by a user S43 II The device shall be able to rest on a table or the user s lap 2 13 Documentation amp User Manual Requirements S44 I Documentation for the proof
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