Blindness is an inability to see, means that a condition where person lacking of ability to interpret information and surrounding due to physiological or neurological factors. According to World Health Organization (WHO), about 314 million people are visually impaired all around the world, 45 million of them are blind and every year that number increased by 1- 2 million [1]. The leading causes of chronic blindness include cataract, glaucoma, age-related macular degeneration, corneal opacities, diabetic retinopathy, trachoma, and eye conditions in children that caused by vitamin A deficiency. Age-related blindness is increasing throughout the world, as is blindness due to uncontrolled diabetes [2].
The Malaysian Association for the Blind (MAB) is the premier voluntary organization in Malaysia serving visually impaired persons that was established in 1951 by the Department of Social Welfare [3]. Notice that, most of blind peoples use traditional walking stick or guide dog to assist them to walk. However, it does not provide detail information about the blind location. Author [4] found that the main difficulties face by blind included walking on the road, finding way, taking a bus and looking for usual life-arena. Blind need someone else to acknowledge the location during walking in unknown environment, thus limit their mobility as well. Nowadays, the enhancement of RFID technology can be adopted in assisting the blind in order to provide better life quality for them. Bin Ding et al. (2007) claim that with the help of walking stick that integrate RFID reader and antenna, the blind can identify the condition of the road and walking route [4].
1.2 Radio Frequency Identification (RFID)
RFID stand for Radio Frequency Identification is an automatic identification technology that uses radio waves to transmit the identity of object or people in the form of a unique serial number. This technology does not require either contact or line of sight for communication between reader and tag [5]. The birth of Radio Frequency Identification was in October 1948 after the publication of a paper by Harry stockman titled "Communications by Means of Reflection Power" [6].
There are three basic components in RFID systems which are transponder, interrogator and the middleware [7, 8]. The transponders commonly refer as RFID tags that contain an electronic microchip, antenna and the encapsulating material. The microchip encoded with a unique serial number that link to entries in a database. The coil antenna use to transmit the data as well as for communication between reader and tag. RFID tag will be placed with the object to be identified.
Second element in RFID system is an interrogator. It is known as RFID reader which is device used to transmit to and receive information from the RFID tag. RFID reader has an antenna that emits the radio wave to read the RFID tag and then passes the data to a computer for processing. Reader's antenna can be external or internal. The third element is a middleware or host computer send the instruction to the reader as well as utilizes the data obtained from the reader in some useful manner.
1.3 Literature Review of RFID system in assisting the blind
RFID technologies are not particularly new and have been applying for many applications such as for transportation payment, product tracking, libraries, human identification, animal identification, security, military and etc.
Besides that, there are some available researches for helping blind people in their navigation. Normally blind people will face with the difficulty to do their daily activity. They have difficulty to sense what happen around them since they cannot see and only depends on their own intuition. People who care about this problem came to contribute their knowledge to assist blind people so that they can be more independence in doing their daily activities.
Tsung-Hsiang Chang et al. (2005) proposed an iCane system [9] that uses RFID technology for assistive the blind with give the useful environment information such as crossroad, intersection, elevators, stairs, nearby shops, virtual government office and etc. An RFID reader integrated to the white cane and communicates with the PDA via Bluetooth. This RFID reader read the ID tags that embedded in the environment and send the ID tags to PDA via Bluetooth. The ID tag would check with the database in the PDA and the result will convert to the speech. The blind would hear output voice by the Bluetooth earphones. This system also has the microphone that user could request the desired location by some voice commands. The SesamoNet system [10, 11] function similarly to iCane system that adopts RFID technology for assisting the blind to identified location. The grid of ID tag are burrowed in the ground a depth of 4 cm in order to be read by the RFID reader that attached to a cane.
Figure: The iCane System Overview [9].
Previous work by the Authors Scooter Wills and Sumi Helal (2005) proposes a solution to the problem of finding ways for the blind in a campus environment by presented an RFID-based information grid system and wearable computing [12]. This system used High Frequency (HF) passive RFID tag that was installed under the flooring in campus environment such as along outdoors pathways, in building hallways and in rooms. The Electronic Travel Aid (ETA) at 2008 also used Passive High Frequency (HF) tags which operate at 13.56 MHz and give the range about 1 meter [13].
The High Frequency reader module SkyeTek M1 and M1-Mini where selected as the RFID readers in system [12] because of their small size and already have integrated antenna. However, these types of reader module only provide about 75 mm read ranges. Authors [9, 12] adopt an external antenna SkyeTek EA1 to the reader and produce the read range about 150mm. The system [12] integrated RFID reader into blind's shoe and walking cane. Whereas system proposed by author [14] at 2007 is RFID reader antenna placed on clothing, the PDA carried in traveler's vest pockets and the RFID tags are wall-mounted.
King Mongkut's University of technology North Bangkok has proposed a blind navigation system using RFID to identify the location information for indoor environment [15] at 2008. The system can be divided into three subsystems which is track infrastructure, navigation device and navigation server. The track infrastructure consist of Low Frequency (LF) RFID tags that store the tag ID location and embedded into a stone block or at sign posts along a pathway. The navigation device is an integrated system that contains the microprocessor unit (MCU), an RFID reader, a communication module, a user interface module and a memory module. The tag and reader communicate each other via radio frequency. When reader received the tag ID, the reader sends it into the MCU via RS-232 cable and GPRS module communicate with the navigation server by bring the information via cellular network. After the navigation server received information about the current location and destination location, the server calculate the shortest route by using the shortest path algorithm.
Some Authors from Malaysia also contribute their knowledge to help blind people and give them more independent in travelling. The authors [16] investigate and enhance the method to estimate the distance between the blind and the sidewalk border by using Radio Frequency Identification Walking Stick (RFIWS). The RFID tag placed in the centre of the sidewalks, RFID reader attached on the walking stick and antenna in the RFID reader. The output voice and vibration will alert the users about the distance between them and the sidewalk's border. The system [16, 17] uses Ultra High Frequency (UHF) that give read range about 3 meters. The authors [17] proposed the Bus Detection Device in order to help blind by using RFID technology. This system gives the information to the user about the bus route, bus number, user's origin location and final destination.
As we can see from the literature review, many researchers from the oversea propose a system to assist the blind for navigation. But just some researchers from Malaysia do on that field and still new on adopting this technology in assisting the blind. Work done by previous RFID researcher in UiTM [16, 17] show that the commercial reader did not quantified the need of the blind. This research study will proceed the previous work by the authors [16, 17] and will focus on the development of the customize UHF RFID reader for assisting the blind. By designing the portable assistive travelling device, hopefully the blind can easily acknowledge the environment and automatically can be independently in their daily activities.
1.4 Literature Review of RFID reader development
Stevan Preradovic et al. (2006) develop a simple low cost active RFID reader that operated in a frequency range from 2GHz to 2.5GHz. The development is focusing on the 3 part which are power supply, controller and Radio Frequency part [8]. Lalit Kumar et al. (2009) design and develop an UHF RFID reader that consists of three parts which are power supply module, microcontroller module and transceiver module with the Intel R1000 reader chip [18]. The 32-bit ATMEL microcontroller will control the R1000 transceiver chip which is a master chip for UHF RFID reader. The design alternately reduces the cost of the existing product of RFID reader. However, this prototype only can read tag within the read distance of 5 to 6 cm.
Chen Ying (2009) describes a verification development platform for UHF RFID reader that compatible with EPC class-1 Gen2 and operating at the 915 MHz frequency band [19]. The reader consists of RF Analog Front end (AFE), the baseband and clock. The baseband is a main task to treat the communication protocol, it is contains FPGA chip with inserted the soft of NIOSII core as a control unit to perform all commands and controls. This NIOSII soft core architecture gives advantages for implementing various kind of RFID standard, and efficiently reduces the design and development time and cost [19].
Chen Ying and Zhang Fu-hong (2009) design UHF reader software using the hierarchical structure included the physical layer and the tag identification layer [20]. Physical layer implemented with FPGA by using Verilog HDL language that conduct the data coding and modulation waveform in reader-to-tag and tag-to-reader signaling. The tag identification layer implemented in NIOSII core embedded in FPGA by using C language to build command that used to identify tags, choosing tags, and modify tags. Implementation of this reader is by using EP2C35F6721 FPGA that has rapid availability and low cost [20].
2.0 PROBLEM STATEMENT
Nowadays, Most of blind people in Malaysia used guide dog or traditional walking stick as the assistive tool for travelling. Travelling is a very difficult process for the people who face on blindness. Thus limit the blind people involve in the society. When they walking and enter a building that they are not familiar with, they are lost and often have to feel their way around. Sometimes they need something or someone else to assist their navigation.
As blind people, they do really hope there must be some portable guide device that assists them to travel in their unknown environment. In view of existing product, most of them are not light weight, large in size and expensive. These market products have limitations in terms of portability. Work done by previous RFID researcher in UiTM show that the commercial reader did not quantified the need of the blind. The development of customize UHF RFID reader can serve the blind for comfortable use the assisting device. By implementing this project, hopefully the blind can be independently in doing their daily activities and easily acknowledge the environment.
3.0 AIMS AND OBJECTIVES OF THE RESEARCH
In view of blind people need for their travelling application, several objectives must be achieved:
To develop UHF RFID reader hardware using FPGA with function to received input from the tag and produces an audio output mechanism.
To integrate the hardware and middleware (GUI) of RFID system in assisting the blind.
To develop a prototype of RFID system that can be used in assisting the blind for travelling.
4.0 SCOPE AND LIMITATION OF THE STUDY
4.1 Scope
This research is about the development of system that can assist the blind people for travel by using RFID system. The system consists of RFID tags, RFID reader, PDA instead of personal computers, Bluetooth headset, and information database. The research project will focus on the development of UHF RFID reader scheme that work at the frequency band from 860MHz to 960MHz and interface it with all elements in this system. These frequency bands are difference depending on the country. So, this project will focus on the frequency range that will operate at Malaysia.
The reader carried by the blind people that will read the information from tag within the read range. RFID tags attached at the object to be identified including building, transport and also tags mounted on the ground at the side way. Blind also will carry the PDA that will retrieval the data from the reader and send the audio output to Bluetooth headset.
4.2 Limitation
Normally the read range which is distance of reader can read between the antenna and the tag is proportional to the output power. When the output power is high, the distance will be longer and when the output power is low, the distance will be shorter.
Notice that longer read range required more power and the product size and weight also will increased. So, it is give challengers to develop the portable reader in order to achieve a longer read range with the smaller size.
5.0 RESEARCH METHODOLOGY
Several stages will be considered to complete this research.
Yes
Yes
Literature Review
Hardware and Software Identification
Reader Development
GUI Development
Final system evaluation
System Integration
System improvement and modification
Start
End
No
No
Test functionality
Test
Test
Run the program
No
No
Yes
Yes
5.1 Literature Review
At the beginning of the research, it is focus on the searching the information about the RFID technology from website, books, journal, and conferences paper. The journal and conference paper review on the field of RFID in assisting the blind for travelling and the development of the reader to get some idea to do this project. The literature review is important to identify the latest development in the areas of research.
5.2 Hardware and Software Identification
At this stage involving the searching on the hardware and software that will be used in the project whereby the hardware must be low in cost. The hardware that will be use to develop RFID reader is Altera FPGA Board and the software is Quartus II. The software that will be use to create a Graphical User Interface (GUI) is Visual Basic.Net; to create a database is Microsoft SQL server.
Besides, the hardware and software that will be use in this project is RFID tags, Bluetooth Headset, computer, Personal Digital Assistance (PDA) and Text To Speech (TTS) software.
5.3 Reader Development
At this stages will focus on development of UHF RFID reader. This reader implemented in Altera FPGA Board and described by using Verilog Hardware Description Language that write in Quartus II software. The implementation of this reader is by using EP2C35F672 FPGA that have rapid availability and low cost. The FPGA chip contains a NIOS II soft core as a control unit to perform all commands and controls. The implementation of NIOS II soft core in cyclone FPGA will provide a cost effective embedded processing solution.
The flow chart below show the activity involve in development of reader by using FPGA:
Yes
Start
Success
No
End
Determine the design specification of reader
Write the modeling algorithm, synthesis and compile
Simulate the Verilog HDL code
Download into FPGA board
5.3.1 Determine the design specification of reader.
The development of this reader start by investigates and determines the design specification of the reader. This involves the theoretical analysis of UHF reader in RFID system. The numbers of desired input and output of the circuit and processing algorithm are determining at this stage.
5.3.2 Write the modeling algorithm, synthesis and compile.
The modeling algorithm is written in Verilog HDL code using Altera Quartus II software. The sub-module of algorithm will write depending on the desired input and output. The basic experiment for testing the sub-module algorithm will conduct to interface between reader and tag, reader's Bluetooth and Bluetooth PDA and Bluetooth PDA to Bluetooth headset. The modeling algorithm then will be synthesis and compile to detect any error on the language code. The purpose of synthesis is to check the design code.
5.3.3 Simulate the Verilog code
After that, the Verilog code will simulate to verify the sequence of logic input and output. The simulation process is running using ModelSim software. The verification regarding to the input sequences and result the System on Chip controller will obtain from this step. The correct result can be verified from the sequence output appear in this level. If the simulation Verilog code fails, the process flow will return to designing the specification of the reader.
5.3.4 Download into FPGA board
If the simulation Verilog code success, the code will download into FPGA board to check the functionalities of the controller (reader).
5.4 GUI Development
The GUI development is designing of Graphical User Interface (GUI) for tagging detection by using the Visual Basic.Net. GUI is an interface between the computer and hardware. It comprises of graphical icons such as text box, label, command button, combo box and etc. Each graphical icon will be program to a specific need such as for the tag detection and retrieval database. At this stage, database will be develop and store in SQL server. The Database contains all the information of the bus route and walking navigation information.
5.5 System Integration
The reader will communicate with the tags that contain the information of unique ID. As know before, the information database was store in the SQL server and attach in the computer. While communication occur between the reader and tag, the reader will send the electromagnetic wave to wake up the tag, then the tag reflect backscatter wave to the reader that contain an unit ID of the tag . The reader will send the unique ID to the computer via Bluetooth and the tag ID will match with the database in SQL server. The information of the tag will be display on the GUI. The information then will convert to the speech by Text To Speech (TTS) software that store in the computer and will be sending to Bluetooth headset.
5.6 System improvement and Modification
At this stage, a PDA will be use instead of computer, and the system will be test on the real field (at campus) to test the functionality of the system.
5.7 Final system evaluation
The final stage of this project is final system evaluation that reader will read the tag and blind will listen to the audio guide through the Bluetooth headset.
6.0 SIGNIFICANT OF STUDY
The development of UHF RFID reader hardware by using FPGA that function to received input information from the tag and produce an audio output mechanism will provide better life for the blind people in doing their daily activities. The information in form of audio output produce by this device will alert the blind about the location or surroundings. The blind can easily acknowledge their location during their navigation.
Most of researcher used High Frequency and Low Frequency signal in their system. The use of Ultra High frequency (UHF) in this project can improve the detection range and will reduce the amount of tags embedded in the environment. It is automatically reduce the cost as well.
Besides, in view of blind people need, they do really hope there must be some portable guide device that can assist them to travel in their unknown environments. This effort of study on developing the portable and light weight UHF RFID reader will give some value to the blind people especially in this country.
