It consisting Mobile app, Arduino, Bluetooth Receiver module, L293D ic etc. The movement of robot is controlled by the voice which catch by the microphone inside the mobile.
Android controlled Microcontroller (Arduino) based Motorized Wheelchair for H...MD. Anamul Haque
Physical disability is a curse to human life. Idea of our project "The Intelligent Wheelchair for Handicapped Persons" has occurred to help the handicapped persons. The fundamental operation of the wheelchair is to facilitate handicapped person with safe movement. For ensuring the safety of movement, obstacle sensing, crack detection and living being identification features have been included. Additionally, a voice controlled LCD has been provided considering the case of auditory disabled people. Access to control basic home appliances has also been offered.
SEE MORE: https://goo.gl/DZvJcc
it is a smart wheelchair which uses voice and bluetooth commands . Also consists of temperature and heartbeat sensors for continuous monitoring by the doctor.
FellowBuddy.com is an innovative platform that brings students together to share notes, exam papers, study guides, project reports and presentation for upcoming exams.
We connect Students who have an understanding of course material with Students who need help.
Benefits:-
# Students can catch up on notes they missed because of an absence.
# Underachievers can find peer developed notes that break down lecture and study material in a way that they can understand
# Students can earn better grades, save time and study effectively
Our Vision & Mission – Simplifying Students Life
Our Belief – “The great breakthrough in your life comes when you realize it, that you can learn anything you need to learn; to accomplish any goal that you have set for yourself. This means there are no limits on what you can be, have or do.”
Like Us - https://www.facebook.com/FellowBuddycom
A Power Point presentation On INDUSTRIAL AUTOMATION...
What is Automation?
As the name suggests ‘Automation’ means to perform automatic operations by means of different kinds of machines.
Automation is the use of control systems and information technologies to reduce the need for human work in the production of goods and services.
It is used to reduce human interference and efforts
Advantages Of PLC:-
Less Wiring.
Wiring between devices and relay contacts are done in the PLC program.
Easier and faster to make changes.
Trouble shooting aids make programming easier and reduce downtime.
Reliable components make these likely to operate for years before failure.
It consisting Mobile app, Arduino, Bluetooth Receiver module, L293D ic etc. The movement of robot is controlled by the voice which catch by the microphone inside the mobile.
Android controlled Microcontroller (Arduino) based Motorized Wheelchair for H...MD. Anamul Haque
Physical disability is a curse to human life. Idea of our project "The Intelligent Wheelchair for Handicapped Persons" has occurred to help the handicapped persons. The fundamental operation of the wheelchair is to facilitate handicapped person with safe movement. For ensuring the safety of movement, obstacle sensing, crack detection and living being identification features have been included. Additionally, a voice controlled LCD has been provided considering the case of auditory disabled people. Access to control basic home appliances has also been offered.
SEE MORE: https://goo.gl/DZvJcc
it is a smart wheelchair which uses voice and bluetooth commands . Also consists of temperature and heartbeat sensors for continuous monitoring by the doctor.
FellowBuddy.com is an innovative platform that brings students together to share notes, exam papers, study guides, project reports and presentation for upcoming exams.
We connect Students who have an understanding of course material with Students who need help.
Benefits:-
# Students can catch up on notes they missed because of an absence.
# Underachievers can find peer developed notes that break down lecture and study material in a way that they can understand
# Students can earn better grades, save time and study effectively
Our Vision & Mission – Simplifying Students Life
Our Belief – “The great breakthrough in your life comes when you realize it, that you can learn anything you need to learn; to accomplish any goal that you have set for yourself. This means there are no limits on what you can be, have or do.”
Like Us - https://www.facebook.com/FellowBuddycom
A Power Point presentation On INDUSTRIAL AUTOMATION...
What is Automation?
As the name suggests ‘Automation’ means to perform automatic operations by means of different kinds of machines.
Automation is the use of control systems and information technologies to reduce the need for human work in the production of goods and services.
It is used to reduce human interference and efforts
Advantages Of PLC:-
Less Wiring.
Wiring between devices and relay contacts are done in the PLC program.
Easier and faster to make changes.
Trouble shooting aids make programming easier and reduce downtime.
Reliable components make these likely to operate for years before failure.
This presentation consisting of home automation using bluetooth controol on the basis of Arduino UNO. Arduino is a rapid proto type , that's why we are using this arduino board. This Arduino UNO consisting of a microcontroller namely ATMEGA328. It has both analog and digital I/O pins inorder to communicate with the external peripherals.
Its a free source of energy we know very well man has needed and used energy at an increasing rate for the sustenance and well-being since time immemorial. Due to this a lot of energy resources have been exhausted and wasted. Proposal for the utilization of waste energy of foot power with human locomotion is very much relevant and important for highly populated countries like India where the railway station, temples etc., are overcrowded all round the clock .When the flooring is engineered with piezo electric technology, the electrical energy produced by the pressure is captured by floor sensors and converted to an electrical charge by piezo transducers, then stored and used as a power source. And this power source has many applications as in agriculture, home application and street lighting and as energy source for sensors in remote locations.
Part of Lecture Series on Automatic Control Systems delivered by me to Final year Diploma in Engg. Students. Equally useful for higher level. Easy language and step by step procedure for drawing Bode Plots. Three illustrative examples are included.
The project is based upon closed loop control system.
A Closed-loop Control System, also known as a feedback control system is a control system which uses the concept of an open loop system as its forward path but has one or more feedback loops (hence its name) or paths between its output and its input.
The reference to “feedback”, simply means that some portion of the output is returned “back” to the input to form part of the systems excitation.
Hi friends
This PPT consist of automation information ,what is PLC,need of PLC applications,components of PLC ,PLC operations,Timers , Some Program, etc
instead of this it consists SCADA ,what is SCADA,need of SCADA,brands of SCADA, tags ,features of SCADA, Dynamic process graphic , script security etc.......
This presentation consisting of home automation using bluetooth controol on the basis of Arduino UNO. Arduino is a rapid proto type , that's why we are using this arduino board. This Arduino UNO consisting of a microcontroller namely ATMEGA328. It has both analog and digital I/O pins inorder to communicate with the external peripherals.
Its a free source of energy we know very well man has needed and used energy at an increasing rate for the sustenance and well-being since time immemorial. Due to this a lot of energy resources have been exhausted and wasted. Proposal for the utilization of waste energy of foot power with human locomotion is very much relevant and important for highly populated countries like India where the railway station, temples etc., are overcrowded all round the clock .When the flooring is engineered with piezo electric technology, the electrical energy produced by the pressure is captured by floor sensors and converted to an electrical charge by piezo transducers, then stored and used as a power source. And this power source has many applications as in agriculture, home application and street lighting and as energy source for sensors in remote locations.
Part of Lecture Series on Automatic Control Systems delivered by me to Final year Diploma in Engg. Students. Equally useful for higher level. Easy language and step by step procedure for drawing Bode Plots. Three illustrative examples are included.
The project is based upon closed loop control system.
A Closed-loop Control System, also known as a feedback control system is a control system which uses the concept of an open loop system as its forward path but has one or more feedback loops (hence its name) or paths between its output and its input.
The reference to “feedback”, simply means that some portion of the output is returned “back” to the input to form part of the systems excitation.
Hi friends
This PPT consist of automation information ,what is PLC,need of PLC applications,components of PLC ,PLC operations,Timers , Some Program, etc
instead of this it consists SCADA ,what is SCADA,need of SCADA,brands of SCADA, tags ,features of SCADA, Dynamic process graphic , script security etc.......
Patients having injuries and physical disabilities and with good mental health face a lot of difficulty when using the conventional hand powered wheelchair. This project enables an economic assembly in any existing wheelchair that enables a smart system for automated motion which can be controlled by any Smartphone. The concept particularly mentions ‘Smartphone’ which covers devices like any Android powered mobile phone which have inbuilt 3 axis accelerometer and Bluetooth Wireless technology. The functionality can be extended to other mobile devices using a suitable application. The other end of the system has a micro controller powers the DC motor for linear motion of the wheelchair. The DC motor connected to the rear wheels enables linear motion.
This is an android based automated wheelchair that can be used by differently able.
• It uses android based Smartphone’s which have inbuilt axis accelerator sensors and Bluetooth wireless technology.
• The proposed concept exploits these features of the smart phones to use at as a transmitter and control device.
• This is an android based automated wheelchair that can be used by differently able.
• It uses android based Smartphone’s which have inbuilt axis accelerator sensors and Bluetooth wireless technology.
• The proposed concept exploits these features of the smart phones to use at as a transmitter and control device.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Wheelchair is truly is mobility orthosis.
A properly prescribed wheelchair can be useful device in reintegrating a person with a disability into the community.
it is a smart wheelchair which uses voice and bluetooth commands . Also consists of temperature and heartbeat sensors for continuous monitoring by the doctor.
Thesis - Voice Control Home AutomationAbhishek Neb
Voice is used in this project for the controlling switches. Reason for choosing voice is because it is easily being reproduced by human. Besides that, usage of voice gives a control system that can be effective and convenient to be used. The application of this system involve modifying the switching system from the traditional way which is physical contact with the switch to a safer way where the usage of voice to replace all the physical contact. This project involve a simple switching system that used the transistor along with relay to do all the connecting of the power to the devices, a voice recognition system that consists of voice recognition chip AT89C51, and the AT89C51 microcontroller to build up the system. The ULN2003 serves as the ear that will listen and interpret the command by the given while the AT89C51 serve as the brain of the system that will coordinate the correct output with the input command given. This project able to recognition the command trained by the user and successfully to execute the correct output. This project is a small scale design which consists of 8 commands that will used to control three different switches. The command is able to individually switch on and switch off each of the switch. Besides that, the command also able to switch on all and off all the switch at the same time.
This project is to develop a wheel chair for physically disabled people
The wheel chair is controlled by hand movement/hand gestures
The gestures are recognized by an accelerometer sensor
An ultrasonic sensor is used to detect the obstacles in front of the chair
The signals from the sensors are processed, and the wheel chair is controlled by Atmega-328 micro controller
Floor cleaning robot report vatsal shah_ec_7th semVatsal N Shah
Households of today are becoming smarter and more automated. Home automation delivers convenience and creates more time for people. Domestic robots are entering the homes and people’s daily lives, but it is yet a relatively new and immature market. However, a growth is predicted and the adoption of domestic robots is evolving. Several robotic vacuum cleaners are available on the market but only few ones implement wet cleaning of floors. The purpose of this project is to design and implement a Vacuum Robot Autonomous and Manual via Phone Application. Vacuum Cleaner Robot is designed to make cleaning process become easier rather than by using manual vacuum. The main objective of this project is to design and implement a vacuum robot prototype by using Arduino Mega, Arduino Shield, LDR Sensor, Real Time Clock, Motor Shield L293D, Ultrasonic Sensor, and IR Sensor and to achieve the goal of this project. Vacuum Robot will have several criteria that are user-friendly.
Mobile networking technologies are the most ubiquitously spread among mankind and with
the technological advances of mobile clients are becoming a prime target for innovative
3D graphics applications.
Our research, presented in this thesis, focuses on new methods of reducing polygonal
models and other commonly used graphical structures in order to bring 3D computer
graphics to devices with limited processor speeds and memory, such as mobile phones.
These environments bring new challenges in algorithm efficiency and data reduction. We
concentrated our effort in three areas: 1. Facial animation on mobile phones, 2. Cooperative
computer graphics in distributed environments and 3. Procedurally generated cities and
buildings.
The aim of the thesis is to be a multidisciplinary publication that combines research
results from fields of computer graphics and mobile networking. We focused on novel
ways to utilize the properties of distributed mobile environments to perform graphical tasks
and overcome various problems in distributed graphical applications caused by occasional
unreliable mobile device network connections.
ACCELEROMETER BASED HAND GESTURE CONTROLLED ROBOT USING ARDUINOSnehasis Mondal
WORKING ARDUINO CODE:
/* * Gesture Recognition Robot * Coder – Raj,Rajib,Saity,Snehasis * This program lets you to control your robot with gesture made by your hand */ int GNDPin=A4; //Set Analog pin 4 as GND int VccPin=A5; //Set Analog pin 5 as VCC int xPin=A3; //X axis input int yPin=A2; //Y axis input int zPin=A1; //Z axis input(not used) int Q1=10,Q2=11,Q3=12,Q4=13; //Output pins to be connected to 10, 11, 12, 13 of Decoder IC long x; //Variabe for storing X coordinates long y; //Variabe for storing Y coordinates long z; //Variabe for storing Z coordinates void setup() { Serial.begin(9600); pinMode(Q1,OUTPUT); pinMode(Q2,OUTPUT); pinMode(Q3,OUTPUT); pinMode(Q4,OUTPUT); pinMode(GNDPin, OUTPUT); pinMode(VccPin, OUTPUT); digitalWrite(GNDPin, LOW); //Set A4 pin LOW digitalWrite(VccPin, HIGH); //Set A5 pin HIGH } void loop() { x = analogRead(xPin); //Reads X coordinates y = analogRead(yPin); //Reads Y coordinates z = analogRead(zPin); //Reads Z coordinates (Not Used) if(x<340) // Change the value for adjusting sensitivity forward(); else if(x>400) // Change the value for adjusting sensitivity backward(); else if(y>400) // Change the value for adjusting sensitivity right(); else if(y<340) // Change the value for adjusting sensitivity left(); else stop_(); } void stop_() { Serial.println(""); Serial.println("STOP"); digitalWrite(Q1,LOW); digitalWrite(Q2,LOW); digitalWrite(Q3,LOW); digitalWrite(Q4,LOW); } void forward() { Serial.println(""); Serial.println("Forward");
digitalWrite(Q1,HIGH); digitalWrite(Q2,LOW); digitalWrite(Q3,HIGH); digitalWrite(Q4,LOW); } void backward() { Serial.println(""); Serial.println("Backward"); digitalWrite(Q1,LOW); digitalWrite(Q2,HIGH); digitalWrite(Q3,LOW); digitalWrite(Q4,HIGH); } void left() { Serial.println(""); Serial.println("Left"); digitalWrite(Q1,LOW); digitalWrite(Q2,HIGH); digitalWrite(Q3,HIGH); digitalWrite(Q4,LOW); } void right() { Serial.println(""); Serial.println("Right"); digitalWrite(Q1,HIGH); digitalWrite(Q2,LOW); digitalWrite(Q3,LOW); digitalWrite(Q4,HIGH); }
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
NO1 Uk best vashikaran specialist in delhi vashikaran baba near me online vas...Amil Baba Dawood bangali
Contact with Dawood Bhai Just call on +92322-6382012 and we'll help you. We'll solve all your problems within 12 to 24 hours and with 101% guarantee and with astrology systematic. If you want to take any personal or professional advice then also you can call us on +92322-6382012 , ONLINE LOVE PROBLEM & Other all types of Daily Life Problem's.Then CALL or WHATSAPP us on +92322-6382012 and Get all these problems solutions here by Amil Baba DAWOOD BANGALI
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Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)
Wheelchair is guided by voice commands full documentation
1. School of Applied technological sciences
Department of Mechatronics engineering
MotoChair: A Fully Motorized Voice-Operated
Wheelchair
Graduation Project I Report
by:
Ala’a Dweikat
Majd Al Yazori
Sa’ed AlDaraghmeh
Supervisor by:
Dr. Aiman Al-Share’, PhD
Dr. Nathir Rawashdeh, PhD
Submitted in partial fulfillment of
the requirements for the degree of
BACHELOR OF SCIENCE
in
Mechatronics Engineering
at
The German Jordanian University
Amman, Jordan
Summer 2012
2. MotoChair: A Fully Motorized Voice-Operated Wheelchair 2012
2
MotoChair: A Fully Motorized Voice-Operated Wheelchair
A Project by
Ala’a Dweikat
Majd Al Yazori
Sa’ed AlDaraghmeh
Supervised by:
_______________________,Head of Mechatronics Engineering Dept.
Dr. Nathir A. Rawashdeh
_______________________,Mechatronics Engineering Dept.
Dr. Aiman Alshare
Evaluated by:
_______________________,Dean, School of Applied Technical Sciences
Dr. Ziyad N.Masoud
_______________________,Mechatronics Engineering Dept.
Dr. Mohammad A. Nazzal
___________________________
Date
3. MotoChair: A Fully Motorized Voice-Operated Wheelchair 2012
3
Acknowledgment
First and foremost, all our gratitude is due to Allah the Almighty for guiding us
through, and aiding us in completing this work successfully.
We would like to express our sincere gratitude to our supervisors Dr. Aiman
AlShare' and Dr. Nathir Rawashdeh, for their help, support and empowerment
throughout this project. We would also like to deeply thank and appreciate the
Mechatronics department at the German Jordanian University, for providing us
with great assistance and insight.
Finally, we would like to thank our families and friends for their love, support
and encouragement.
A. Dweikat
M. Al Yazori
S. AlDaraghmeh
4. MotoChair: A Fully Motorized Voice-Operated Wheelchair 2012
4
Abstract
This project aims to design, integrate, program, interface and test a fully
motorized, voice-operated wheelchair. A regular standard wheelchair was used
as the main skeleton that has been on modified to meet this project’s goals. In
this project, the procedure of Mechatronic systems design was followed to
assure the quality of the final product i.e. the MotoChair. The project has
consisted of the following parts: Hardware, software, interface and testing.
Finally, a working prototype in addition to a complete comprehensive
documentation will be submitted prior to a project defence session at the
German Jordanian University.
Keywords:
Mechatronics engineering, Interface, Assistive technology, Mobility aids,
Powerchair, Motorized wheelchair, Voice recognition, Disabled, Battery
powered wheelchair.
6. MotoChair: A Fully Motorized Voice-Operated Wheelchair 2012
6
Table of Contents
2.1.1 Advantages of DC series motors.......................................................................................... 11
2.1.2 Series Motor Operation .................................................................................................. 11
2.1.3 Reversing the Rotation.................................................................................................... 12
2.2 Power and Torque calculations .......................................................................................... 13
2.3 Gear Box Calculations:....................................................................................................... 15
2.4 Extra pulley calculations: ................................................................................................... 15
Gears.................................................................................................................................. 15
Belts................................................................................................................................... 16
Chapter 3: Electrical Design......................................................................................................... 21
3.1 Drive circuit...................................................................................................................... 21
3.2 Pulse width modulation PWM............................................................................................ 27
3.2.1 PWM Duty cycle andfrequency ................................................................................... 27
3.2.2 Averaging the PWMmicrocontroller output ................................................................. 28
3.3 Voice recognition kit.......................................................................................................... 28
3.3.1 What is voice recognition?........................................................................................... 28
3.3.2 Features of the HM2007 voice recognition kit.............................................................. 29
3.4 The Battery....................................................................................................................... 30
3.4.1 Wheelchair batteries overview .................................................................................... 30
Chapter 4: Conceptual Design...................................................................................................... 33
4.1 Functional Block diagram of the system.............................................................................. 33
4.2 Joystick commands flow chart............................................................................................ 34
4.3 Voice commands flow chart............................................................................................... 35
4.4 Component list.................................................................................................................. 36
Chapter 5: Control Method ......................................................................................................... 37
Chapter 6: Software and Interfacing ............................................................................................ 38
6.1 Microcontroller selection and programming....................................................................... 38
6.2 Voice recognition kit programming..................................................................................... 40
Programming.......................................................................................................................... 40
Testing Recognition................................................................................................................. 40
Chapter 7: Testing and Performance............................................................................................ 43
7.1 Actual speed measurement ............................................................................................... 43
7.2 accuracy of the wheelchair's voice commands at a quite environment................................. 44
7. MotoChair: A Fully Motorized Voice-Operated Wheelchair 2012
7
7.3 accuracy of the wheelchair's voice commands at a noisy environment................................. 45
Chapter 8: Challenges and Difficulties.......................................................................................... 48
Chapter 9: Further development................................................................................................. 49
Possible additions to this project:................................................................................................ 49
References................................................................................................................................. 50
Appendix.................................................................................................................................... 51
Components' information and datasheets................................................................................ 51
200V N-Channel MOSFET..................................................................................................... 51
BJT (2N3055). ......................................................................................................................... 51
SERIES MOTOR WITH GEAR BOX .............................................................................................. 52
PIC 16F877A microcontroller................................................................................................... 52
Battery:.................................................................................................................................. 53
HM2007 speech recognition:................................................................................................... 54
Voltage Regulator:.................................................................................................................. 55
Datasheet from Ibn Sina Center for Medical Equipment and Services......................................... 56
Software Code........................................................................................................................ 57
Extra Pictures ......................................................................................................................... 62
8. MotoChair: A Fully Motorized Voice-Operated Wheelchair 2012
8
Chapter 1: Introduction
This Document contains information about the project “MotoChair: A
Motorized Voice-Operated Wheelchair”. This project is done as a graduation
prerequisite for the Bachelor of Science in Mechatronics engineering at the
German Jordanian University.
1.1 Project Description
This project aims to design, integrate, program, interface and test a fully
motorized, voice-operated wheelchair. A regular standard wheelchair was used
as the main skeleton that has been on modified to meet this project’s goals. In
this project, the procedure of Mechatronic systems design was followed to
assure the quality of the final product i.e. the MotoChair. The project has
consisted of the following parts: Hardware, software, interface and testing.
Finally, a working prototype in addition to a complete comprehensive
documentation will be submitted prior to a project defence session at the
German Jordanian University.
Keywords:
Mechatronics engineering, Interface, Assistive technology, Mobility aids,
Powerchair, Motorized wheelchair, Voice recognition, Disabled, Battery
powered wheelchair.
1.2 Objectives
This projectaims to:
1. Design, integrate, program, interface and test a fully motorized, voice-
operated wheelchair.
2. Apply the major engineering skills and use the engineering knowledge
acquired fromthe study of Mechatronics engineering.
3. Appreciate the importance of coordinated team work.
9. MotoChair: A Fully Motorized Voice-Operated Wheelchair 2012
9
4. Integratebetween the engineering knowledgeand the needs of
everyday life.
5. Know that any technology gains its importance fromthe value it adds to
our lives, and fromits role in solving a problemor satisfying a need.
1.3 Team
This project was conducted by the following Mechatronics Engineering
students at the German Jordanian University as a prerequisite to their
graduation, under the supervision and guidance of Dr. Aiman AlShare’, PhD &
Dr. Nathir Rawashdeh, PhD.
1. Ala’a Dweikat
2. Majd Al-Yazori
3. Sa’ed AlDaraghmeh
1.4 The theory behind this project
Assistive Technology (AT), that refers to hardware and software solutions for
persons with physical, cognitive or sensory disabilities, can help people to have
a more productive and pleasant lives. There are several physical
disabilities/conditions which require the use of a wheelchair including brain
injury, stroke, fractures, amputation, pulmonary disease, neurological
disorders, musculoskeletal diseases/injuries and spinal cord injuries. In such
cases the use of a wheelchair can bring an enhanced independence that will
increase the user’s quality of life. However some of the impairments cause
severe difficulties on the use of wheelchair manual or electric. [1]
In a survey aimed to collect information from patients concerning the
usefulness of new electric wheelchairs. The study concluded that 9 to 10 % of
patients who use power chairs and who received appropriate training “find it
extremely difficult or impossible to use the wheelchair for activities of daily
10. MotoChair: A Fully Motorized Voice-Operated Wheelchair 2012
10
living”. Some of the pointed reasons aredifficulty on controlling the wheelchair
with a joystick, uncomfortable and inappropriate interface for the disability
(because users with severe motor impairments are unable to operate the
joystick smoothly).
For elderly patients arthritis is one of the major reasons for wheelchair use.
The repeated usage of joysticks and continuous wrist movements can be very
painful for an arthritic patient, and may result in reinforced difficulties. For the
referred groups of users a voice based interface is highly encouraging because
it represents a natural and simple way of controlling the device. For other
types of disabilities different types of interfacing devices can be used.
The first known application of a voice interface for controlling a wheelchair
was published by Staton et al.. The voice interface provided basic commands
for wheelchair movement and no real world experiences were performed. In
2002 the RoboChair have been developed, with three operating modes:
intelligent obstacle avoidance, collision detection, and contour following. It
uses mixed voice and joystick inputs and a fuzzy control system. A third-party
speech recognition system was used. The VOIC is a Voice Operated Intelligent
Wheelchair. The voice recognition uses a neural network for pattern detection
with a self organizing architecture. The systemwas evaluated on two scenarios
with distinct users and SNRs (Signal to Noise Ratio). The announced error rate
for the 5 words vocabulary, in Slovenian, was 1.8% for a quiet environment
and 6.4% with heavy background noise (no SNR was specified). [1]
11. MotoChair: A Fully Motorized Voice-Operated Wheelchair 2012
11
Chapter 2: Mechanical Design
2.1 Series DC motors
In this project two 12V Series DC motors were used. Series motors are
commonly used as traction motors in many applications, as they offer high
starting torque, are robust, have a simple design and are relatively low cost.
Most of their applications are of an industrial nature, such as conveyors, but
are also common in road-going electric vehicles. DC series motors are an ideal
choice for battery-operated equipment over AC motors, as they don’t require
the use of expensive complicated inverter circuitry to convert the DC voltage
to an AC voltage required by the motor.
2.1.1 Advantages of DC series motors
• Hugestarting torque
• Simple Construction
• Designing is easy
• Maintenance is easy
• Costeffective
2.1.2 Series Motor Operation
Operation of the series motor is easy to understand. In Figure 2.1 you can see
that the field winding is connected in series with the armature winding. This
means that power will be applied to one end of the series field winding and to
one end of the armature winding (connected at the brush).
When voltage is applied, current begins to flow from negative power supply
terminals through the series winding and armature winding. The armature is
not rotating when voltage is first applied, and the only resistance in this circuit
will be provided by the large conductors used in the armature and field
windings. Since these conductors are so large, they will have a small amount of
resistance. This causes the motor to draw a large amount of current from the
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The figure bellow demonstrates a schematic of the series DC motor:
Figure 2.2: Series DC motor schematic
2.2 Power and Torque calculations
The Rotational Speed of each of the available motors = 4000 rpm.
The relation between the rotational speed and power is given by the equation:
𝑇𝑜𝑟𝑞𝑢𝑒 =
𝑂𝑢𝑡𝑝𝑢𝑡 𝑃𝑜𝑤𝑒𝑟
𝑅𝑜𝑡𝑎𝑡𝑖𝑜𝑛𝑎𝑙 𝑆𝑝𝑒𝑒𝑑
𝐸 𝑎 = 𝑉𝑡 − 𝐼 𝑎( 𝑅 𝑎 + 𝑅𝑓)
𝐸 𝑎 = 12𝑉 − 12.5 × (0.05Ω + 0.02Ω) = 11.125 𝑉
Where:
𝐸 𝑎 is the armature voltage (Volt).
𝑉𝑡 is the total voltage (12V).
𝐼𝑎 is the armature current (Ampere).
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𝑅 𝑎 is the armature resistance (Ohm).
𝑅𝑓 is the field resistance (Ohm).
𝑷 𝒅 = 𝐼 𝑎 × 𝐸 𝑎
𝑷 𝒅 = 12.5 𝐴𝑚𝑝 × 11.125 𝑉 = 139.063𝑊
Where:
𝑷 𝒅 is the Electrical power developed inside the motor.
𝜏 𝑒 =
𝑃𝑑
𝜔 𝑚𝑜𝑡𝑜𝑟
=
139.063
2 × 𝜋 ×
4000
60
= 0.33198 𝑁. 𝑚
Where:
𝜏 𝑒 is the electrical torque developed inside the motor (N.m).
𝜔 𝑚𝑜𝑡𝑜𝑟 is the rotational speed of the motor (r.p.m).
𝜔 𝑚𝑜𝑡𝑜𝑟 = 2 × 𝜋 ×
𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑟𝑜𝑡𝑎𝑡𝑖𝑜𝑛𝑠 𝑝𝑒𝑟 𝑚𝑖𝑛𝑢𝑡𝑒
60
𝑆𝑒𝑐𝑜𝑛𝑑
𝑚𝑖𝑛𝑢𝑡𝑒
𝑃𝑜𝑢𝑡 = 𝑃𝑑 − 𝑃𝑟
Where:
𝑃𝑜𝑢𝑡 is the mechanical output power of the motor (Watt).
𝑃𝑟 is the rotational power losses (%).
𝜏 𝑠ℎ𝑎𝑓𝑡 =
𝑃𝑑 − 𝑃𝑟
𝜔 𝑚𝑜𝑡𝑜𝑟
= 𝜏 𝑒 × 0.9 = 0.3 𝑁. 𝑚
Where:
𝜏 𝑠ℎ𝑎𝑓𝑡 is the mechanical torque on the shaft.
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2.3 Gear Box Calculations:
By using a gear box with a step down ratio = 0.08 we find that:
𝜔𝑔𝑒𝑎𝑟 = 0.08 × 𝜔 𝑚𝑜𝑡𝑜𝑟 = 0.08 × 4000 = 320 𝑟𝑝𝑚
Where:
𝜔𝑔𝑒𝑎𝑟 is the rotational speed of the gear (r.p.m).
𝜔 𝑚𝑜𝑡𝑜𝑟 is the rotational speed of the motor (r.p.m).
And:
𝜏 𝑔𝑒𝑎𝑟 =
𝑃𝑜𝑢𝑡
𝜔 𝑚𝑜𝑡𝑜𝑟
=
125.666
2 × 𝜋 ×
320
60
= 3.75 𝑁. 𝑚
Where:
𝜏 𝑔𝑒𝑎𝑟 is the torque on the gear.
2.4 Extra pulley calculations:
Gears and belts transmit rotary motion from one shaft to another, often
changing speed and torque in the process. Gear sets are generally used where
the two shafts are close together. Belts and pulleys, or sheaves, on the other
hand, link shafts that are farther apart. [15]
Gears
A pair of gears reduces speed in proportion to the relative number of teeth.
The gear on a motor shaft is typically smaller and has fewer teeth than the one
on the machine shaft. The speed ratio is R = NL/NS, where NL = number of
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Taking into consideration that the Power output from motor is reserved; it will
be transmitted to the pulley with small losses in tension in the belt.
𝐷 𝑔𝑒𝑎𝑟 = 5 𝑐𝑚
𝐷 𝑝𝑢𝑙𝑙𝑦 = 20 𝑐𝑚
Where:
𝐷𝑔𝑒𝑎𝑟 is the diameter of the small pulley attached to the gearbox.
𝐷 𝑝𝑢𝑙𝑙𝑦 is the diameter of the large pulley attached to the wheel.
To find the rotational speed of the large pulley:
𝐷1 𝑛1 = 𝐷2 𝑛2
0.05 𝑚 × 320 𝑟𝑝𝑚 = 0.2 𝑚 × 𝑛2 − −→ 𝑛2 = 80 𝑟𝑝𝑚
Where:
𝐷1 is the diameter of the small pulley attached to the gearbox.
𝐷2 is the diameter of the large pulley attached to the wheel.
𝑛1 is the rotational speed of the small pulley attached to the gearbox.
𝑛2 is the rotational speed of the large pulley attached to the wheel.
From the power equation:
𝑃2 = 𝑃1 × (1 − 𝑃𝑟)
𝑃2 = 125.666 × (1 − 0.10) = 113.099 𝑊
Where:
𝑃1 is the power of the small pulley attached to the gearbox (Watt).
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𝑃2 is the power of the large pulley attached to the wheel (Watt).
𝑃𝑟 is the Frictional power losses in the belt (assumed 10%).
Thus:
𝜏 𝑝𝑢𝑙𝑙𝑒𝑦 =
𝑃𝑜𝑢𝑡
𝜔 𝑚𝑜𝑡𝑜𝑟
=
113.099
2 × 𝜋 ×
80
60
= 13.50 𝑁. 𝑚
Where:
𝜏 𝑝𝑢𝑙𝑙𝑒𝑦 is the torque on the large pulley attached to the wheel.
𝑉𝑒𝑙𝑜𝑐𝑖𝑡𝑦 𝑜𝑓 𝑡ℎ𝑒 𝑏𝑒𝑙𝑡 ( 𝑉𝑏𝑒𝑙𝑡 ) =
𝜋 × 𝑛1 × 𝐷1
60
=
𝜋 × 320 × 0.05
60
𝑉𝑏𝑒𝑙𝑡 = 0.8377 𝑚
𝑠⁄
Where:
𝑉𝑏𝑒𝑙𝑡 is the theoretical velocity of the belt.
Assuming the max load = 100 kg:
𝜏 𝑟𝑒𝑞𝑢𝑖𝑟𝑒𝑑 = 𝜏𝑙𝑜𝑠𝑠𝑒𝑠 + ( 𝐽 ×∝ )
Where:
𝜏𝑙𝑜𝑠𝑠𝑒𝑠 is the torque losses (N.m).
J is the second moment of area (kg.m2
).
∝ is the rotational acceleration.
𝐽 = 𝑚𝑎𝑠𝑠 × 𝑟2
= 100𝑘𝑔 × 0.3𝑚2
= 9 𝑘𝑔. 𝑚2
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Where:
𝑟 is the radius of the Wheel (It's diameter = 0.6 m).
The figure bellow shows the speed profile of the wheelchair. The speed profile
is obtained from the assumption that the wheelchair will accelerate from 0 to
0.5 m/s speed in 1 second. Then it will continue its motion in a constant speed
equals to 0.5 m/s.
Figure 2.4: Speed profile of the wheelchair
We want the wheelchair toreacha constant speed of (0.5 m/s) during (1
second):
Fromprofile speed we determine the angular acceleration and then the
required torqueas follows:
𝛼 =
𝑎
𝑟
Where:
0
0.1
0.2
0.3
0.4
0.5
0.6
01234
Speed Profileof the WheelChair
Speed (m/s)
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𝛼 is the angular acceleration of the Wheel ( 𝑟𝑎𝑑
𝑠2⁄ ).
𝑎 is the linear acceleration of the wheel ( 𝑚
𝑠2⁄ ).
𝑎 =
0.5
𝑚
𝑠
1 𝑠
= 0.5 𝑚
𝑠2⁄
𝛼 =
0.5
𝑚
𝑠2
0.3 𝑚
= 1.666 𝑟𝑎𝑑
𝑠⁄
𝜏 𝑟𝑒𝑞𝑢𝑖𝑟𝑒𝑑 = 0.8 𝑁. 𝑚 + 9
𝑘𝑔
𝑚2
× 1.666
𝑟𝑎𝑑
𝑠2
= 15 𝑁. 𝑚
Because we have 2 motors (one for each wheel) we need a total torque of:
27.0 N.m. This value is based on the extreme conditions of operation, i.e. the
belt losses are10% and the Load = the max load = 100 Kg at the required speed
profile.
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Chapter 3: Electrical Design
The electrical design of this project consisted of motors' drive circuit, battery,
Pulse width modulation, the voice recognition kit and the connections
between them, in addition to the connection with the joystick and
microphone.
3.1 Drive circuit
Drive circuit is a circuit used for the purpose of controlling another circuit of
component, in order to control and regulate their operation. Motor drives
have been developed to offer power supply for the motors and isolate the
electronic components, such as the ICs, from electrical problems.
One popular type of motor drive circuits is the H-Bridge (sometimes called: the
Full Bridge). It has been named that because it looks like the letter H when
viewed on the discrete schematic. An H-Bridge is an electronic circuit that
allows the voltage to be applied on the load in either direction. It is used to
allow DC motors to operate in two opposite directions i.e. forward and
Backward. The direction of rotation of a series motor can be changed by
changing the polarity of either the armature or field winding.
The figure bellow shows a schematic of a simple H-Bridge:
Figure 3.1: simple H-Bridge
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The table bellow shows the direction of rotation of the Wheelchair based on
the direction of rotation of the two motors.
Left motorRight motorDirection
ON ( CW )ON ( CW )Forward
ON ( CCW )ON ( CCW )Backward
ON ( CW )OFFRight
OFFON ( CW )Left
Table 3.1: Wheelchair motion
Where:
CW: Clockwise
CCW: Counter Clockwise
The table bellow shows the direction of rotation of the motors based on the
state of the transistors i.e. on – off.
Direction
Left motor Right motor
Transistor 1 Transistor 2 Transistor 3 Transistor 4
Non 0 0 0 0
Forward 1 0 1 0
Reverse 0 1 0 1
Right 1 0 0 0
Left 0 0 1 0
Table 3.1: the direction of rotation of the motors based on the state of the
transistors
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Drive circuit simulation:
In order to verify our design prior to the circuit's actual construction a
computer simulation was conducted using the software: Proteus VSM version
7.6.
Proteus Virtual System Modeling (VSM) combines mixed mode SPICE circuit
simulation, animated components and microprocessor models to facilitate co-
simulation of complete microcontroller based designs. The simulation takes
place in real time (or near enough to it): a 1GMHz Pentium III can simulate a
basic 8051 system clocking at over 12MHz. Proteus VSM also provides
extensive debugging facilities including breakpoints, single stepping and
variable display for both assembly code and high level language source. [12]
The following figure shows the simulation:
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The pictures bellow show the actual testing circuit built for this projectand the
motors relay box:
The relay box
The drive circuit
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3.2.2 Averaging the PWM microcontroller output
We need to average the PWM signal by converting it to a useful analogue
signal so that we can benefit from it. This is done by using a capacitor as a low
pass filter, in which the output frequency will decrease as the input frequency
increases.
3.3 Voice recognitionkit
In this projectthe HM2007 voicerecognition kit was used.
3.3.1 What is voice recognition?
Voice recognition is "the technology by which sounds, words or phrases
spoken by humans are converted into electrical signals and these signals are
transformed into coding patterns to which meaning has been assigned. While
the concept could more generally be called "sound recognition", but the focus
is on the human voice because we most often and most naturally use our
voices to communicate our ideas to others in our immediate surroundings. In
the context of a virtual environment, the user would presumably gain the
greatest feeling of immersion, or being part of the simulation, if they could use
their most common form of communication, the voice. The difficulty in using
voice as an input to a computer simulation lies in the fundamental differences
between human speech and the more traditional forms of computer input.
While computer programs are commonly designed to produce a precise and
well-defined response upon receiving the proper (and equally precise) input,
the human voice and spoken words are anything but precise. Each human
voice is different, and identical words can have different meanings if spoken
with different inflections or in different contexts. Several approaches have
been tried, with varying degrees of success, to overcome these difficulties. [13]
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3.4 The Battery
3.4.1 Wheelchair batteries overview
[http://www.apparelyzed.com/wheelchair/electric-wheelchairs.html]
There are three different battery types that can be used in electric
wheelchairs. These are "Wet", "Gel", and the newer "AGM (Absorbed Glass
Mat)" types. Their properties are listed below:
Wet Batteries
Wet batteries use the chemical reaction between lead and sulphuric acid to
create electrical energy. As the batteries need filling with distilled water, they
do have a higher maintenance rate, but are lighter than Gel or AGM batteries.
Wet batteries are also prone to leakage, something which is important if you
intend to put your wheelchair in the hold of an aircraft.
Positive Aspects
Cheaper.
Less vulnerable to overcharging.
Great performancewith carefulmaintenance.
Lighter per Ah (AmpereHour) compared to most Gel or AGMs.
Negative Aspects
require maintenance.
Battery acid can leak, causing corrosion and damage to chair and wiring.
Not approved for airline travel.
High rate of self-dischargewhen left sitting (6-7% per month).
Gel Batteries
Gel batteries contain a mixture of sulphuric acid, fumed silica, pure water, and
phosphoric acid, which forms a thixotropic gel. As there is no liquid in the
battery, they do not leak or require maintenance like wet batteries.
Positive Aspects
No maintenance.
Cannot leak.
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Operate better than wet batteries in low temperatures.
Less gas released when charging than wet batteries.
Approved for air travel.
Longer life cycle than wet batteries
Negative Aspects
Expensive.
More weight per Ah than wet batteries.
Susceptible to overcharging.
AGM Batteries
AGM batteries have an absorbent glass mat sandwiched between the plates,
saturated with acid electrolyte, but with none free to spill. This “sandwich”
allows uniform distribution of the electrolyte over the plates, and reduces the
chance of battery damage caused by vibration and jarring.
Positive Aspects
No maintenance.
Can’t spill or leak.
Shock resistant.
Minimal gasses released when charging.
Low self-dischargerate (3% per month at 77’F).
Approved for air travel.
Negative Aspects
Highest cost.
Susceptible to overcharging.
3.4.2 The battery used in this project
In this project a regular car battery (ACDelco 46B24L) was used as a proof of
concept; Due the availability of this type, its price and the lack of special
electrical wheelchairs' batteries in the market. However, using a car battery is
not a good choice for this application becauseit is a starting (Cranking) battery;
which is designed to deliver quick bursts of energy for short periods of time
and is not design for long operation periods. Whereas such application
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requires a Deep Cycle battery; which has less instant energy, but greater long-
term energy delivery. [18]
These are some typical (minimum - maximum) typical expectations for
batteries if used in deep cycle service. There are so many variables, such as
depth of discharge, maintenance, temperature, how often and how deep
cycled, etc. that it is almost impossible to give a fixed number. [19]
Starting: 3-12 months
Golf cart: 2-7 years
AGM deep cycle: 4-8 years
Gelled deep cycle: 2-5 years
Deep cycle (L-16 type etc): 4-8 years
Industrialdeep cycle (Crown and Rolls 4KS series): 10-20+years.
NiFe (alkaline): 5-35 years
NiCad: 1-20 years
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Chapter 4: Conceptual Design
4.1 Functional Block diagram of the system
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4.4 Component list
Regular Wheelchair (Adult size).
Voice recognition kit.
Drive circuit
o Microcontroller.
o Relays.
o Transistors.
o Resistors.
Voltage regulator to get 5v for microcontroller.
Battery 12v 40A.
2 motors 12.5 A 12V 1/8 HP + A gearbox ( to increase torque and decrease
speed of the motor)
2 Belts ( to connect pulley with motors )
2 pulleys ( to increase torque and decrease speed of motor )
Joystick
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Chapter 5: Control Method
In this project an open-loop control approach was used in order to reduce the
system's complexity. We assumed that the user will control the wheelchair as
they see suitable and then adapt to the operation of the system. Although
some control on the wheels rotation must be added at least, but this might be
solved by manipulating the Pulse width modulation and adding a
compensation factor (multiplier) to the software code to make the weaker
wheel rotate faster than the other. This will help in overcoming the differences
of the speeds of rotation in the wheels.
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Chapter 6: Software and Interfacing
6.1 Microcontroller selectionandprogramming
A microcontroller is a small computer built for the purpose of executing
specific tasks. It is manufactured on a single small integrated circuit (IC) and
used mainly in products that require giving the user some degree of control on
the operation. Microcontrollers are designed for embedded applications not
like the microprocessors or the other general purpose applications.
Microcontroller have many advantages that make it the number one candidate
to be used in automatically controlled devices such as remote controls, power
tools, office machines, automobile engine control systems and other
embedded systems.
Advantages of microcontrollers:
Microcontrollers are cost effective and very cheap to replace while
microprocessors are 10 times more expensive.
They require less power.
All-in-one: they usually contain a CPU, ROM, RAM and I/O ports.
The above mentioned reasons made it very suitable for us to choose the
controller of the wheelchair to be a microcontroller (PIC 16F877A). The code
was programmed using MicroBasic programming language and then tested
and simulated in the German Jordanian University's Microcontroller and
Microprocessor laboratory, before being installed on the PIC microcontroller.
*Check the Appendixfor more information about the microcontroller used and
to see the software code.
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The following Pictures demonstrate the PIC16F877A microcontroller and its
programmer:
Figure 6.1: PIC 16F877A microcontroller
Figure 6.2: PIC programmer
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6.2 Voice recognitionkit programming
When the kit is turned on the HM2007 checks the static RAM periodically. In
case that everything is ok, the screen displays "00" and the red light goes on. It
is now ready for commands.
Programming
Programming the circuit starts by pressing (on the keypad) the word number
that is desired to save a sound command on it. The circuit can save up to 40
words. When the number(s) is pressed on the keypad, the red light goes off
and the number will be displayed on the screen. The next step is to press "#" to
start saving the sound command. Then the command can be spoken in a clear
way. Finally the LED should blink momentarily to show that the command has
been saved. The process continues until the desired number of commands
(given that it should be within the memory range of the kit) is saved.
Testing Recognition
The circuit is continually listening. Repeat a trained word into the microphone.
The number of the word should be displayed on the digital display. For
instance if the word "directory" was trained as word number 25. Saying the
word "directory" into the microphone will cause the number 25 to be
displayed.
Programming our commands:
In our project we saved each command two times (one in a quite environment
and the other in a noisier one) to assure that the system will be able to
recognize the commands in different situations without the need to implement
some sophisticated noise reduction or elimination techniques.
However, this method is not highly reliable and was used as a proof of concept
and will be altered in any further development ventures.
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Figure 6.4: The voice kit, the display and the keypad
Figure 6.5: Our Voice circuit connected to the drive circuit
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Chapter 7: Testing and Performance
7.1 Actual speed measurement
The actual speed of the wheelchair was measured in a flat surfacewith a user
weight = 80kg. Severaltrials were conducted in which the distancecrossed was
4m, and the times were recorded. The averagetime of the trials resulted in 7s
per 5 meters. Therefore the theoretical and experimental speeds will be:
(1)Theoretical speed(𝑽𝒕𝒉𝒆𝒐𝒓𝒊𝒕𝒊𝒄𝒂𝒍 ):
𝜋 × 𝑛1×𝐷1
60
=
𝜋 × 320𝑟𝑝𝑚 × 0.05𝑚
60
= 𝟎. 𝟖𝟑𝟕𝟕 𝒎
𝒔⁄
(2)Experimental Speed(𝑽 𝒆𝒙𝒑𝒆𝒓𝒊𝒎𝒆𝒏𝒕𝒂𝒍 ):
Weight of the Testing person = 80 kg.
Distance: 5 meters
Time: 7 seconds
𝑉𝑒𝑥𝑝𝑒𝑟𝑖𝑚𝑒𝑛𝑡𝑎𝑙 =
5𝑚
7𝑠
= 𝟎. 𝟕𝟏𝟒𝟑 𝒎
𝒔⁄
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7.2 accuracy ofthe wheelchair's voice commands at a quite
environment
A series of 10 trials were conducted in a quite environment (indoors with
minimum noise), and the responses of the system were observed to test the
percentage error of the voice recognition in a quite environment. The results
were as follows:
Trials Forward Reverse Right Left
Done Error Done Error Done Error Done Error
Trial 1
Trial 2
Trial 3
Trial 4
Trial 5
Trial 6
Trial 7
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Trial 8
Trial 9
Trial 10
error 10% 10% 20% 20%
7.3 accuracy ofthe wheelchair's voice commands at a noisy
environment
A series of 10 trials were conducted in a noisy environment (outdoors with
cars'and surroundings'noise), and the responses of the system were observed
to test the percentage error of the voice recognition in a noisy environment.
The results were as follows:
Trials Forward Reverse Right Left
Done Error Done Error Done Error Done Error
Trial 1
Trial 2
Trial 3
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7.4 Battery life
Due to the fact that the battery used in this project is a regular car starting
battery, we could not obtained any scientifically reliable data on its life time
per charge; because its operational life was short and we needed to recharge it
many times during the testing phase of this project. However, we have
contacted some commercial electric wheelchairs suppliers in the market and
obtained some data regarding the battery life time per charge (in terms of the
distance crossed) of the regular power wheelchairs.
The battery specifications for a commercial electric wheelchair obtained from
Ibn Sina Center for Medical Equipment and Services –Amman, Jordan:
Battery : 26AH X 12V X 2pcs. (option: 40AH)
Charger : 24V, 4AMP (Automatic Type)
Battery Weight : 20 Kgs (10Kgs X 2pcs.)
Continues travelling distance: 21 Km (Option 40AH batteries: 33Km)
*The data above are intended to illustrate the normal battery life per charge
for one of the available commercial electric wheelchair, and may not apply to
the case of this project due to differences in other factors.
To see the complete datasheet, refer to the Appendix.
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Chapter 8: Challenges and Difficulties
Throughout the making of this project we encountered several challenges
difficulties. Some of them we were able to manage, but others we were not.
The major challenge was to find and obtain the required components from the
Jordanian market especially the motors and the battery.
Also we encountered a great challenge in finding the suitable pulleys and fixing
them to the wheels without affecting the motion of the wheels. Several trials
were done but none was successful. In order to overcome this obstacle, we
had to design a new mechanism for the wheels in which a new shaft was made
using a turning machine, then two sets of bearings were added to the shaft
outside the wheel. Thus we were able to fix the pulleys with the wheels
without affecting the motion of the latter ones.
The battery was another challenge and it very hard to find a suitable battery
for the electric wheelchair application, in an affordable price. Batteries of this
kind can be found at the medical equipment supplier but with very expensive
prices. Therefore we used a regular battery for the purpose of proving the
concept.
Finally, we faced several difficulties in programming and debugging the
software. The major one was that at the beginning after the code was
simulated and verified, it did not work in the real application. We tried
countless times to fix this problem and changed several PIC microcontrollers
but this did not solve the problem. After a long period of trials we found that
the voltage regulator was corrupted (the microcontroller was not getting the
required 5V) and needed to be replaced!
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Chapter 9: Further development
After working on this project, we found that the electric wheelchair market in
Jordan is far away from saturation and it still needs a lot of contributions in this
area. This project can be –with a small effort- commercially worthwhile.
The major area of necessary improvement is the noise elimination in order to
get the best voice operation functionality. Many sophisticated methods can be
used such as Real-time adaptive noise cancellation for automatic speech
recognition, but an excellent quality microphone with noise isolation may be
sufficient.
Also a well reliable control method is very essential to this project and the
safety of its user. A PID controller may be added in addition to torque sensors
and speed feedback to ensure the perfect operation of the system in all
environments especially starting, stopping and breaking at inclined surfaces.
Possible additions tothis project:
After completing the major milestones of this project, one or more of the
following feature might be added to it.
1. Emergency stop system.
2. User Bio-Feedback.
3. Foldable multi-purposetable.
4. GPS emergency system(GPS/E911).
5. Solar battery charging.
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References
[1] Coelho, L & Braga, D. zGo: A Voice Operated Wheelchair with Biosignal Monitoring for
Home Environments. Proceedings of the 2th International Conference on Software
DevelopmentforEnhancingAccessibility and Fighting Info-Exclusion, June 3-5, Porto Salvo,
Portugal. 2009. http://www.danielabraga.com/PDF/DSAI09_3.4.p84.pdf
[2] Mano, M et al.. Wheelchair for physically disabled people with voice, ultrasonic and
infrared sensor control. Aotonomous Robotics, 2, 203-224. 1995.
[3] http://en.wikipedia.org/wiki/Motorized_wheelchair
[4] http://www.nskelectronics.com/files/hm2007_voice_recog_kit.pdf
[5] http://www.imagesco.com/articles/hm2007/SpeechRecognitionTutorial02.html
[6] http://zone.ni.com/devzone/cda/ph/p/id/53
[7] http://www.lmphotonics.com/DCSpeed/series_dc.htm
[8] http://www.rehab.research.va.gov/
[9] http://electric-wheelchairs-pro.com/
[10] http://www.robotroom.com/HBridge.html
[11] http://www.mcmanis.com/chuck/robotics/tutorial/h-bridge/
[12] http://www.labcenter.com/index.cfm
[13] http://www.hitl.washington.edu/scivw/EVE/I.D.2.d.VoiceRecognition.html
[14] http://www.engineersgarage.com/microcontroller/
[15] http://www.microchip.com/pagehandler/en-us/family/16bit/architecture/home.html
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Appendix
Components' informationand datasheets
200V N-Channel MOSFET
IRF640B
Features:
18A, 200V, RDS(on) = 0.18Ω @VGS = 10 V
Fast switching
BJT (2N3055).
Ic max VcE max hFE min Ptot max Category
(typical use)
15 A 60 V 20 117 W General
purpose, high
power
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SERIES MOTOR WITH GEAR BOX
The name plate:
Vn (V) In (A) n1 Before gear
box
n1 After gear
box
Rg no.
12 12.5 4000 rpm 320 rpm 11AIM186002
PIC 16F877A microcontroller.
Pin diagram:
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Feature for PIC 16F877A:
Key feature Pic 16F877A
Operating frequency DC – 20 MHz
Resets ( and delays) POR, BOR (PWRT,OST)
FLASH program memory (14-bit
words)
8K
Data memory (bytes) 368
EEPROM Data memory (bytes) 256
interrupts 15
I/O ports Ports A,B,C,D,E
Timers 3
Capture/Compare/PWM modules 2
Serial communication MSSP,USART
Parallel communication PSP
10-Bit Analog-to-digital module 8 input channels
Analog comparators 2
Instruction set 35 instructions
packages 40-pin PDIP
Battery:
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HM2007 speech recognition:
Features for HM2007:
Single chip voice recognition CMOS LSI.
Speaker –dependent isolates-word recognition system.
External 64k SRAM can be connected directly.
Maximum 40 words can be recognized for one chip.
Maximum 1.92 sec of words can be recognized.
Two control mode is supported: manual and CPU mode.
Response time: less than 300ms
A microphone can be connected directly.
5V single power supply.
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Voltage Regulator:
Electrical Characteristics (KA7805)
(Refer to test circuit, 0°C < TJ < 125°C, IO = 500mA, VI =10V, CI= 0.33μF, CO=0.1μF,
unless otherwise specified)
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Datasheet from IbnSina Center for Medical Equipment and Services
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Software Code
Programwheelchair
dim j as byte
dim v as byte
main:
trisb = $ff 'define portb as input
trisd = $ff 'define portd as input
trisc = $00 'define portc as output
pwm_init (5000) 'initialize the PWMwith a desired frequency in
Hz
pwm_start 'starts PWM
if portd.3 = 1 then 'check the selector button if pressed or no
delay_ms (300)
goto joy
else
delay_ms (300)
goto voice
end if
joy:
while true
j = portd 'the four direction of joystick and the selector
button(selector d3)
select casej
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case $18 'left
pwm_change_duty(90) 'changes PWM duty ratio
portc.4 = 0 'output to transistor1
portc.5 = 0 'output to transistor2
portc.6 = 1 'output to transistor3
portc.7 = 0 'output to transistor4
case $28 'right
pwm_change_duty(90) 'changes PWM duty ratio
portc.4 = 1
portc.5 = 0
portc.6 = 0
portc.7 = 0
case $48 'forward
pwm_change_duty(240) 'changes PWM duty ratio
portc.4 = 1
portc.5 = 0
portc.6 = 1
portc.7 = 0
case $88 'backward
pwm_change_duty(90) 'changes PWM duty ratio
portc.4 = 0
portc.5 = 1
portc.6 = 0
portc.7 = 1
case else 'if we not press any button
portc.4 = 0
portc.5 = 0
portc.6 = 0
portc.7 = 0
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end select
delay_ms(200)
if portd.3 = 0 then 'Confirmation of the selector case
goto voice
end if
wend
voice:
portc.4 = 0 'output to transistor1
portc.5 = 0 'output to transistor2
portc.6 = 0 'output to transistor3
portc.7 = 0 'output to transistor4
while true
v = portb 'the output of SRC
select case v
case $81,$82 'forward
pwm_change_duty(240) 'changes PWM duty ratio
portc.4 = 1
portc.5 = 0
portc.6 = 1
portc.7 = 0
delay_ms(1000)
case $83,$84 'backward
pwm_change_duty(90) 'changes PWM duty ratio
portc.4 = 0
portc.5 = 1
portc.6 = 0
portc.7 = 1
delay_ms(1000)
case $85,$86 'right
pwm_change_duty(90) 'changes PWM duty ratio
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end select
if portd.3=1 then 'Confirmation of the selector case
goto joy
end if
wend
end.
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ExtraPictures