Ultrasonic Cane For The Blind : Transmitter And Receiver.
ULTRASONIC CANE FOR THE BLIND: TRANSMITTER AND RECEIVER
MAZLIYANA BINTI AYUB
This report is submitted in partial fulfillment of the requirements for the award of Bachelor of Electronic Engineering (Industrial Electronics) With Honours
Faculty of Electronic and Computer Engineering Universiti Teknikal Malaysia Melaka
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UNIVERSTI TEKNIKAL MALAYSIA MELAKA
FAKULTI KEJURUTERAAN ELEKTRONIK DAN KEJURUTERAAN KOMPUTER BORANG PENGESAHAN STATUS LAPORAN
PROJEK SARJANA MUDA II
Tajuk Projek : ULTRASONIC CANE FOR THE BLIND: TRANSMITTER AND RECEIVER
Sesi
Pengajian : 2008/2009
Saya MAZLIYANA BINTI AYUB mengaku membenarkan Laporan Projek Sarjana Muda ini disimpan di Perpustakaan dengan syarat-syarat kegunaan seperti berikut:
1. Laporan adalah hakmilik Universiti Teknikal Malaysia Melaka.
2. Perpustakaan dibenarkan membuat salinan untuk tujuan pengajian sahaja.
3. Perpustakaan dibenarkan membuat salinan laporan ini sebagai bahan pertukaran antara institusi pengajian tinggi.
4. Sila tandakan ( √ ) :
SULIT*
(Mengandungi maklumat yang berdarjah keselamatan atau kepentingan Malaysia seperti yang termaktub di dalam AKTA RAHSIA RASMI 1972)
TERHAD* (Mengandungi maklumat terhad yang telah ditentukan oleh organisasi/badan di mana penyelidikan dijalankan)
TIDAK TERHAD
Disahkan oleh:
__________________________ ___________________________________
(TANDATANGAN PENULIS) (COP DAN TANDATANGAN PENYELIA)
Alamat Tetap: 271, Jalan Fajar, Felda Lubuk Merbau,
06710 Pendang, Kedah.
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“I hereby declare that this report is the result of my own work except for quotes as cited in the references.”
Signature : ………..
Author : MAZLIYANA BINTI AYUB
Date : ……….
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“I hereby declare that I have read this report and in my opinion this report is sufficient in terms of the scope and quality for the award Bachelor of Electronic
Engineering (Industrial Electronic) With Honours.”
Signature : Supervisor’s Name :
Date :
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Dedicated for my beloved father and mother…
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ACKNOWLEDGEMENT
Firstly, I would like to dedicate my highest gratitude to Allah SWT for giving me the strength to complete this final project.
I would like to express my heartfelt gratitude to my supervisors, Pn. Siti Khadijah binti Idris for guiding this work with utmost interest, patience, cares and scientific rigor. I am grateful to her for setting high standards and giving me the freedom to explore many things. Thank you for the time and experiences shared as well as additional knowledge gained as I believe that I would not get this kind of opportunity elsewhere.
I am thankful to my family for bearing with me during this venture and providing the strength to persist. Finally, a special mention for my friends in the department, whose support and suggestions went along way in making this work a reality. Thank you.
.
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ABSTRACT
The purpose of this project is to develop the Electronic Travel Aid for the blind people. It will involve the ultrasonic technology to be more useful and reliable compare to the classical cane in order to provide fully automatic obstacle avoidance with audible notification. Developments in embedded systems have opened up a vast area of research and development for affordable and portable assistive devices for the physically challenged. Besides, it is design to consume less power, portable in size and has an acceptable accurate performance in object distance. This project aimed at the design and implementation of a detachable unit which acts to augment the functionality of the existing white cane, to allow knee-above obstacle detection. However, due to its inherent limitation, the classical method does not provide the protection for the body. Consequently, there is no guarantee that’s the presence of obstacle, can be detected by the blind to avoid a collision. The cane developed helps a blind person find way without any difficulty in terms of improving the social life for the blind pedestrian.
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ABSTRAK
Projek ini bertujuan untuk membina satu alat bantuan pergerakan elektronik untuk orang buta. Ia melibatkan teknologi ultrasonik dan dijangka dapat menggantikan tongkat sedia ada. Ciri bagi alat bantuan ini termasuk menyediakan pengesanan halangan automatik sepenuhnya melalui penghasilan bunyi. Selain itu, alat bantuan perjalanan elektronik (ETA) ini, menjimatkan kerana penggunaan kuasa yang minimum dan saiz yang kecil membolehkan ia dibawa dengan mudah. Walaubagaimanapun, berdasarkan keadaan semasa, tongkat yang terdahulu tidak dapat menyediakan perlindungan kepada tubuh badan. Oleh itu, tiada jaminan kepada halangan yang bakal dihadapi dapat dikesan oleh orang buta pada masa yang sama dapat mengelakkan daripada berlakunya perlanggaran. Selain daripada meningkatkan kemajuan alat bantu terdahulu dan menggantikannya, ia merupakan satu pembaharuan dalam peningkatan kehidupan sosial golongan orang kurang upaya ini.
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TABLE OF CONTENTS
CHAPTER CONTENTS PAGE
TITLE I
VERIFICATION OF REPORT III
VERIFICATION BY SUPERVISOR IV
DEDICATION V
ACKNOWLEDGEMENT VI
ABSTRACT VII
ABSTRAK VIII
TABLE OF CONTENTS IX
LIST OF TABLES XIII
LIST OF FIGURES XIV
LIST OF ABBREVIATIONS XVI
LIST OF APPENDIX XVII
I INTRODUCTION 1
1.1 Project Background 1
1.2 Project Objectives 2
1.3 Problem Statements 3
1.4 Scope of Works 4
1.5 Advantages of Ultrasonic Cane 5
1.6 Thesis Summary 6
II LITERATURE REVIEW 7
2.1 Background of Cane 7
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2.2 Types of Cane 9
2.3 History of Cane 10
2.4 Canes Around The World 11 2.5 How The Ultrasonic Cane Works 11
2.6 Ultrasound Ranging 12
2.7 Functional Descriptions 13
2.8 Obstacles 14
2.9 Sensors 15
2.9.1 Type of sensor 16
2.10 Sonar Sensor 19
2.11 The MaxSonar-EZ1 20
2.12 Advantages Of Using Ultrasonic 21 Sensor Compared To Another Sensor
2.12.1 Advantages of ultrasonic sensor 21 2.12.2 Disadvantages of infra-red sensor 22 2.12.3 Disadvantages of laser 22 2.12.4 Another advantage 23 2.13 Feeding safe and confident 23
III METHODOLOGY 24
3.1 Hardware 24
3.1.1 The main board 25 3.1.2 Ultrasonic sensor 27 3.1.3 The Circuitries 27
3.2 Project Work Flow 30
3.3 Project Block Diagram 31
3.4 Software 33
3.5 Negotiation Common Obstacles 33
3.6 Obstacles 35
3.7 Angle Of The Cane 35
3.7.1 Beam Width 37
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IV RESULTS AND ANALYSIS 39
4.1 Hardware Part 39
4.2 Result Obtained 41
4.2.1 Ultrasonic Board 41
4.2.2 Acceptable Voltage Indicator 45 4.3 Experimentation And User Validation 46 4.4 Detection Of Knee Above Obstacles 46 4.5 Negotiating Common Obstacle 48
4.6 Other Observation 48
4.7 Packaging 49
4.7.1 Casing 49
4.7.2 Specifications 49
4.8 Problems And Troubleshooting 50
4.8.1 Hardware 50
4.8.2 Software 50
4.9 Analysis 51
4.9.1 Angle Detection Zone 51
4.9.2 Audio Warning Zone 52
V DISCUSSION AND CONCLUSION 53
5.1 Discussion 53
5.2 Conclusion 55
VI FUTURE DEVELOPMENT 56
6.1 Introduction 56
6.2 Intelligent Cane 57
6.3 Conceptual Design 59
6.3.1 Device Needed 60
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VII REFERENCES 63
VIII APPENDIX 64
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LIST OF TABLES
NO TITLE PAGE
3.1 PIC PORT B Connection 26
3.2 PIC PORT A Connection 26
3.3 Division of Detection Range into Sub-Ranges and 36
Corresponding Patterns
4.1 Audio Warning Zone 52
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LIST OF FIGURES
NO TITLE PAGE
2.1 Long Cane 9
2.2 ID Cane 10
2.3 Ultrasound Based Ranging 13
2.4 Sonar Range Finder 21
3.1 Ultrasonic Sensor 27
3.2 The Power Supply Circuit 27
3.3 The Main Circuit 28
3.4 Acceptable Voltage Indicator Circuits 29
3.5 Process Flow Chart 30
3.6 Project Block Diagram 31
3.7 Path Finding 34
3.8 Side View Illustrating The Horizontal And Vertical Coverage Of The Detection Zone
34
3.9 Detection Cone 36
3.10 Top Views Showing The Horizontal And Angular Coverage Of The Detection Zone For Long Range Mode (left) and Short Range Mode (right)
37
3.11 Four Different Scenarios Returning The Same Sensor Output 38
4.1 Ultrasonic Cane 39
4.2 Details Of Design 40
4.3 No Obstacle Detected 41
4.4 Obstacle Detected 42
4.5 PCB Layouts With Component Footprint 42
4.6 Component Footprint 43
xiv
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4.7 Original Size 43
4.8 Original Size Of Additional Circuit 45
4.9 Mirror Track. 46
4.10 Detection Of Raised Side Of A Truck 47
4.11 Detection Of Raised Horizontal Bar 47
4.12 Path Finding Experiment 48
4.13 Different Grips For Holding The White Cane 48
4.14 Predicted Detection Area 51
4.15 Actual Detection Area 51
4.16 Sounds Versus Distance 52
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LIST OF ABBREVIATIONS
PSM - Projek Sarjana Muda IC - Integrated Circuit
PIC - Programmable Integrated Circuit DC - Direct Current
AC - Alternate Current I/O - Input or Output
IP/OP - Input Port or Output Port LED - Light Emitting Diode
SONAR - SOund Navigation And Ranging
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LIST OF APPENDIX
NO TITLE PAGE
A The ‘Smart’ Cane Project From Indian Institute Of 64 Technology Delhi
B The MaxSonar-EZ1 High Performance Sonar Range Finder 68
C Sonar Explorer 70
D A Collection Of Ultrasonic Cane Project 72
E Project Cost 75
F Programming the PIC16F84 76
G PIC Projects 78
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CHAPTER 1
INTRODUCTION
1.1Background
The Malaysian Association for the Blind (MAB) estimates that there are 63,000 people in the Malaysia, who are blind, and 53,000 people are having a bad blurry of eye.Therefore, both the size of the market and the size of the need for the technology proposing are large. The virtual cane coupled with an ordinary cane will allow unprecedented navigational power to those who need it. Products developed for the visually impaired have typically focused on communication devices such as reading machines and embossing printers for Braille. Navigational aids beyond the cane have yet to be developed in a manner leading to their acceptance by the visually impaired community. The primary impediment to produce a marketable version of the proposed technology is the form factor. The product must be easy to use and lightweight. The potentially small size makes it a very attractive option for this product. As more markets are developed for this technology, the sensor will be able to be manufactured in high volume at very low cost. This is an added benefit for those in need of affordable assistive navigational tools. As both technologies mature, the virtual cane will be able to be mass produced and refined. The device proposes is simple and should be no more difficult to use than an ordinary cane. The rich amount
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of information available to the user is a tremendous benefit and the novel way in which it is presented to the user make the virtual cane technology an important milestone in assistive devices.
1.2Objectives
In expanding the idea of helping the blind, two main objectives are the target to be achieved upon completion of this project.
The first objective is to develop a model of cane for the blind. The most widely used primary mobility aid today is the long cane. The goal of this design is to improve upon the limitations of the long cane and to replace it.
The second objective is to design ETA prototype that consumes less power, portable in size and has an acceptable accurate performance in object distance detection (using sensor) in order to provide fully automatic obstacle avoidance with audible notification.
The design of a small portable cane will be useful for the blind people. It is easier for them to find ways on daily activities without having to use the standard mobility aid available for individuals with this disability. Since the mobility aids are small and light, it is easily, portable and can be taken anywhere.
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1.3Problem Statements
For aided orientation and mobility, majority of the blind people use a long cane, which provide an extended spatial sensing within and are about 0.5 meters ahead of the user. However, the long cane does not provide protection to their body. The long cane has several limitations such as a range limited to the length of the cane, typically one pace ahead of the user, difficulties detecting overhanging obstacles, and safe storage in public places. Due to its inherent limitations, the long cane does not provide protection for the body above the waist elevation. Consequently, there is no guarantee that the presence of obstacles such as low slung signposts, utility boxes, tree branches, overhanging wires, can be detected by the blind person in time to avoid a collision.
An Electronic Travel Aid (ETA) is a form of assistive technology having the purpose of enhancing mobility for the blind pedestrian. The blind people find traveling difficult and hazardous because they cannot easily determine where things are, a process otherwise known as spatial sensing. Thus the problem of mobility can be reframed as a problem in spatial sensing. The techniques for spatial sensing are well known, radar, sonar, and optical triangulation methods being the most common, and the latter two have been incorporated into a wide variety of past ETA designs
However, there are many problems with currently available devices. First, the rangefinder technology is unreliable in its detection of step-downs or step-ups, such as curbs. Secondly, blind users find the sounds of various pitches or tactile vibrations being used to code the spatial information to be esoteric and difficult to understand.
Thirdly, most blind users do not find the slight improvement in mobility performance to be worth the extra cost which can be many thousands of dollars, and the additional worry of maintaining a complex, expensive battery operated system that m
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1.4Scope of Work
The motivation for this project was to design an electronic mobility aid for the blind. The goal of this project is to design Electronic Travel Aid (ETA) for the blind and to improve upon the limitations of the long cane and to replace it. It will involved ultrasound technology to be more useful and reliable than classical cane. The ultrasonic cane is use to allow the blind people for aided orientation and easy mobility. The prototype is fitted in a ‘flashlight-like’ enclosure made of a PVC tube with an external battery pack as power supply, an earphone for the audible output and a range of 0 up to 1 meter.
The open ultrasonic sensor manufactured gold foil stretched over a grooved plate. The grooved, metallic back plate in contact with the insulated side of the foil forms a capacitor which, when charged, exerts an electrostatic force to the foil thus transforming electrical energy into acoustical waves. Similarly the energy flow can be reversed to transform the returning echo into electrical energy.
In this design, ultrasound is radiated out and the returning ultrasonic echo’s are translated back down into the audible domain and presented binaurally to the blind user. The time based cues responsible for spatial hearing are encoded upon the sound, thereby creating the illusion of an externalized auditory image located out in space at the detected object's position. In this approach, one of the significant drawbacks is that the user must wear earphones, which can interfere with the listening of normal environmental sounds.
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1.5Advantages of Ultrasonic Cane
Several advantages were identified during interaction with this product.
1.5.1 Light Weight Design
Since the cane is small and light; it is easily portable and can be taken anywhere. This product is a lightweight rechargeable battery provides power. The unit should be light in weight without adding extra weight to the existing cane and at the same time without compromising in terms of strength, particularly impact strength and the user should be able to use the unit at length without getting fatigued.
1.5.2 Low power consumption
PIC16F84A consist of 18-pin Enhanced FLASH/EEPROM 8-bit microcontroller. It’s used the low power, high speed technology and the characteristic is <2mA typical @ 5V, 4 MHz and 15 µA typical @ 2V, 32 kHz
1.5.3 Other Design Features
It is fully automatic obstacle avoidance with audible notification. All buttons on the module should be non-protruding type and should possess Braille markings for easy identification. Also all the above requirements have to be met within an affordable cost target. The unit should be such that it has flexibility to be used by users having different styles of holding and gripping.
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1.6Thesis Summary
This thesis consists of six (6) chapters which are Introduction, Literature Review, Methodology, Results and Analysis, Discussion and Conclusion and Future Development.
Chapter 1 is the introduction of the main idea including the advantage and important of this project.
Chapter 2 is the literature review that discussed about the types of sensor will be use in the development of the Ultrasonic Cane for the Blind project. This includes the explanations about how will the cane works.
Chapter 3 is the methodology while focused on hardware and software design of the Ultrasonic Cane. It will be focused on obstacle sensing which is using the PIC Microcontroller as a main controller. In this section, software development such as software compiler, software design will be discussed further.
Chapter 4 is results and analysis whereas all the results obtained and the analysis of the project is identified. All discussions are concentrating on the result of Ultrasonic sensor board. This chapter also discusses the problem that faced for this project.
Chapter 5 is discussion and conclusion, will be discussed the conclusion for this project after the entire task is completed.
Chapter 6 is future development that discussed the further development of the project that can be added into the classification for improving.
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CHAPTER 2
LITERATURE REVIEW
2.1 Background of Cane
This research intends to bring "intelligence" into the long cane by providing overhanging obstacle detection capabilities to the cane users. For this purpose, a self-contained, miniaturized ultrasonic ranging module with microelectronics will be designed, prototyped, and integrated into the shaft of a long cane. Upon obstacle detection, a human voice signal, describing in key words the distance and height of the obstacle, will be displayed to provide orientation assistance. Compared to electronic travel aids (ETAs) developed in the past, the "smart" long cane will be ergonomic in design, easy to use, easy to maintain, less expensive, and much more compatible with daily travel situations. It will provide a useful tool to the blind community in terms of increased mobility, which is a prerequisite for employment and an independent, substantial social life.
10% of people considered legally blind also have mobility impairment, leading to reliance on others for mobility. Although there are limited specialty options available for blind people with mobility impairments, people have been successful using the current obstacle detection options like ultrasonic or infrared sensors.
(1)
of information available to the user is a tremendous benefit and the novel way in which it is presented to the user make the virtual cane technology an important milestone in assistive devices.
1.2Objectives
In expanding the idea of helping the blind, two main objectives are the target to be achieved upon completion of this project.
The first objective is to develop a model of cane for the blind. The most widely used primary mobility aid today is the long cane. The goal of this design is to improve upon the limitations of the long cane and to replace it.
The second objective is to design ETA prototype that consumes less power, portable in size and has an acceptable accurate performance in object distance detection (using sensor) in order to provide fully automatic obstacle avoidance with audible notification.
The design of a small portable cane will be useful for the blind people. It is easier for them to find ways on daily activities without having to use the standard mobility aid available for individuals with this disability. Since the mobility aids are small and light, it is easily, portable and can be taken anywhere.
(2)
1.3Problem Statements
For aided orientation and mobility, majority of the blind people use a long cane, which provide an extended spatial sensing within and are about 0.5 meters ahead of the user. However, the long cane does not provide protection to their body. The long cane has several limitations such as a range limited to the length of the cane, typically one pace ahead of the user, difficulties detecting overhanging obstacles, and safe storage in public places. Due to its inherent limitations, the long cane does not provide protection for the body above the waist elevation. Consequently, there is no guarantee that the presence of obstacles such as low slung signposts, utility boxes, tree branches, overhanging wires, can be detected by the blind person in time to avoid a collision.
An Electronic Travel Aid (ETA) is a form of assistive technology having the purpose of enhancing mobility for the blind pedestrian. The blind people find traveling difficult and hazardous because they cannot easily determine where things are, a process otherwise known as spatial sensing. Thus the problem of mobility can be reframed as a problem in spatial sensing. The techniques for spatial sensing are well known, radar, sonar, and optical triangulation methods being the most common, and the latter two have been incorporated into a wide variety of past ETA designs
However, there are many problems with currently available devices. First, the rangefinder technology is unreliable in its detection of step-downs or step-ups, such as curbs. Secondly, blind users find the sounds of various pitches or tactile vibrations being used to code the spatial information to be esoteric and difficult to understand.
Thirdly, most blind users do not find the slight improvement in mobility performance to be worth the extra cost which can be many thousands of dollars, and the additional worry of maintaining a complex, expensive battery operated system that m
(3)
1.4Scope of Work
The motivation for this project was to design an electronic mobility aid for the blind. The goal of this project is to design Electronic Travel Aid (ETA) for the blind and to improve upon the limitations of the long cane and to replace it. It will involved ultrasound technology to be more useful and reliable than classical cane. The ultrasonic cane is use to allow the blind people for aided orientation and easy mobility. The prototype is fitted in a ‘flashlight-like’ enclosure made of a PVC tube with an external battery pack as power supply, an earphone for the audible output and a range of 0 up to 1 meter.
The open ultrasonic sensor manufactured gold foil stretched over a grooved plate. The grooved, metallic back plate in contact with the insulated side of the foil forms a capacitor which, when charged, exerts an electrostatic force to the foil thus transforming electrical energy into acoustical waves. Similarly the energy flow can be reversed to transform the returning echo into electrical energy.
In this design, ultrasound is radiated out and the returning ultrasonic echo’s are translated back down into the audible domain and presented binaurally to the blind user. The time based cues responsible for spatial hearing are encoded upon the sound, thereby creating the illusion of an externalized auditory image located out in space at the detected object's position. In this approach, one of the significant drawbacks is that the user must wear earphones, which can interfere with the listening of normal environmental sounds.
(4)
1.5Advantages of Ultrasonic Cane
Several advantages were identified during interaction with this product.
1.5.1 Light Weight Design
Since the cane is small and light; it is easily portable and can be taken anywhere. This product is a lightweight rechargeable battery provides power. The unit should be light in weight without adding extra weight to the existing cane and at the same time without compromising in terms of strength, particularly impact strength and the user should be able to use the unit at length without getting fatigued.
1.5.2 Low power consumption
PIC16F84A consist of 18-pin Enhanced FLASH/EEPROM 8-bit microcontroller. It’s used the low power, high speed technology and the characteristic is <2mA typical @ 5V, 4 MHz and 15 µA typical @ 2V, 32 kHz
1.5.3 Other Design Features
It is fully automatic obstacle avoidance with audible notification. All buttons on the module should be non-protruding type and should possess Braille markings for easy identification. Also all the above requirements have to be met within an affordable cost target. The unit should be such that it has flexibility to be used by users having different styles of holding and gripping.
(5)
1.6Thesis Summary
This thesis consists of six (6) chapters which are Introduction, Literature Review, Methodology, Results and Analysis, Discussion and Conclusion and Future Development.
Chapter 1 is the introduction of the main idea including the advantage and important of this project.
Chapter 2 is the literature review that discussed about the types of sensor will be use in the development of the Ultrasonic Cane for the Blind project. This includes the explanations about how will the cane works.
Chapter 3 is the methodology while focused on hardware and software design of the Ultrasonic Cane. It will be focused on obstacle sensing which is using the PIC Microcontroller as a main controller. In this section, software development such as software compiler, software design will be discussed further.
Chapter 4 is results and analysis whereas all the results obtained and the analysis of the project is identified. All discussions are concentrating on the result of Ultrasonic sensor board. This chapter also discusses the problem that faced for this project.
Chapter 5 is discussion and conclusion, will be discussed the conclusion for this project after the entire task is completed.
Chapter 6 is future development that discussed the further development of the project that can be added into the classification for improving.
(6)
CHAPTER 2
LITERATURE REVIEW
2.1 Background of Cane
This research intends to bring "intelligence" into the long cane by providing overhanging obstacle detection capabilities to the cane users. For this purpose, a self-contained, miniaturized ultrasonic ranging module with microelectronics will be designed, prototyped, and integrated into the shaft of a long cane. Upon obstacle detection, a human voice signal, describing in key words the distance and height of the obstacle, will be displayed to provide orientation assistance. Compared to electronic travel aids (ETAs) developed in the past, the "smart" long cane will be ergonomic in design, easy to use, easy to maintain, less expensive, and much more compatible with daily travel situations. It will provide a useful tool to the blind community in terms of increased mobility, which is a prerequisite for employment and an independent, substantial social life.
10% of people considered legally blind also have mobility impairment, leading to reliance on others for mobility. Although there are limited specialty options available for blind people with mobility impairments, people have been successful using the current obstacle detection options like ultrasonic or infrared sensors.