UNIVERSITY AT BUFFALO
Requirements Document
Remote Control Wheelchair With Collision
Avoidance
Joseph D’Amato
Husein Rashed
Steven Ostertag
Rohan Vivek
T. S. Rockwell
The Problem
People with disabilities that affect their motor skills restrict their ability to operate a power chair. A
monitoring system to prevent collisions as well as a complete control system will be of great benefit to
teachers and caregivers.
Our aim is to allow disabled individuals to control a motorized wheelchair without the worry of a
collision with objects as well as a system that will give a teacher or caregiver complete control of the
wheelchair to direct the individual with the added benefit of collision avoidance. A user may also find
great use for a remote that can retrieve their wheelchair from a distant location.
This projects creates an easier interaction and fosters a strong link between the teachers/caregivers and
the severely disabled or handicapped. Some of the great benefits or experiences that this will create for
teachers/caregivers include:
1.
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The ability to control the wheelchair at any time.
Remotely enhance the movements of the wheelchair through the controller.
The ability to facilitate independent movement of the individual with increased safety precautions.
Alerting notifications during emergency situations.
Confident stress-free control.
History:

Wheelchairs have a long history and have been used for a long time primarily to help people with
disabilities. People with only physical disabilities have the luxury of piloting their own wheelchairs
which gives them a strong sense of being as good as mobile people. But people with severe
cognitive and physical disabilities lose this sense of freedom and independence. For such people,
handling their own wheelchairs might be an impossible task with the current technology and
products available.

The first wheelchair was invented in 1500s, but since then very less and slow progress has been
made in this field. Although the motorized wheelchair was a great achievement in the history of
wheelchairs, evolving from simple platform on wheels to using technologies like motors, electrical
controls and computerized processing, but they are still far from the optimal solution with the
technological advancements that have been made.

There are many different groups and universities which are working towards improving motorized
wheelchairs including voice, eye, tongue and gesture controls, but all of them are still in the
process of development. Even though there are prototypes of wheelchairs coming out, but all of
them are really expensive, or complex to handle.
Research:

As mentioned above, there has been great level of academic interest shown towards this kind of
problem in the recent times. Many groups have been producing prototypes of the wheelchair.

Researchers at Saitama University in Japan have developed a computer controlled chair with the
ability to automatically follow a targeted individual and avoid simple obstacles.
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
The wheelchair is a standard motorized model with retrofitted laser sensors and laptop computer
support. This design has applications in allowing more than one wheelchair to be controlled at a
time as they can lock onto a lead chair and follow its lead.

Company GeckoSystems announced their plan to develop an automated wheelchair that uses
Microsoft’s Kinect technology to identify obstacles and navigate around them. The advantage of
this approach is the low cost of the Kinect unit and plethora of development and documentation
available for the system.
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A group at Luleå University of Technology in Sweden has designed a wheelchair with a built in
laser sensing system that creates a planar map of the environment to assist in navigation for
visually impaired people. Their future plans include expanding the laser to be able to create a full
3D map around the user.
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Although we can see that there have been solutions to this, but most of them are in development
phase. Current solutions are all overpriced and all of them require the patients to pilot their
wheelchairs.
Current Solutions:

Powered wheelchair - There are many options for motorized wheelchairs, many of which can be
purchased for as low as $500. These wheelchairs also have a good weight limit and user
controls. The powered wheelchair will allow the user to move it without straining their arms.
However the disadvantage of this wheelchair is that it lacks remote control from a caregiver, and
only has
onboard controls. Some users may not be able to use the on board controls due to disabilities,
and sometimes the caregivers may want to have control over the user.

Voice controlled autonomous wheelchair : A group at MIT is developing an automated
wheelchair that can learn the area around itself through voice commands. It will map out the
areas around it and learn to navigate from place to place. The wheelchair is advanced enough to
learn the layout of a building
once it is taken on a tour and told of specific places. Although mostly working, this is still in early
development stages and is not available for purchase. Also, this implementation involves setting
up an extensive Wi-Fi network in the building to allow it to map and navigate the building. It
cannot be used outdoors or any place without a network connection. This solution also does not
have dedicated controls, so it will only function in the spaces that it has already mapped out.

Eye gaze wheelchair : The eye gaze wheelchair will eventually allow patients to control a
wheelchair simply by using their eyes. This system will provide many more people with mobility
that they were not able to use on any other wheelchair systems. Although this will provide mobility
to many people, it is still in early development stages. This will also require extensive training for
5 the patient to use the wheelchair effectively. This wheelchair may also result in over straining of
the patients eyes due to overuse. Lastly, accidental operation of this wheelchair could be a safety
hazard if the patient is looking around, not realizing that they are operating the wheelchair before
it is too late.
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Problems with current solutions:

Wheelchair needs to be piloted by the patient.
o No danger sensors or detectors.
o Current solutions very expensive.
o Most of the solutions still under development.
o Most of the technologies in current wheelchairs cater to specific set of disabled people.
User Needs:
The user will be able to control the wheelchair as they would with a regular power chair, but with the
added benefit of collision avoidance. The wheelchair will stop preventing a collision. This upgrade to the
power wheelchair will allow individuals the confidence to use a power wheelchair without the dangers that
can go along with it.
Customer Needs:
The objective is to allow the teachers to maintain easier, stronger, and faster interaction with any given
handicapped individual. Not only that, but part of this objective is to maintain a safe environment for that
interaction to occur, providing the teachers with an actively safe and supervised environment. This major
goal is an integral of many design objectives that needs to occur. Such design objectives/goals include
the following:
1. Hardware control and input processing from the remote steering unit
This is the major component of the entire design. In its most basic a wireless controller in the
teacher’s hand. This will allow the teacher to interrupt any occurring processes and send any input
commands to the wheelchair. These commands can be basic inputs for possible features on
the wheelchair, or inputs that provide major hardware control. The teacher will have the ability to navigate
the wheelchair, thus providing effective control when needed. Some of the hardware requirements
needed to fulfill these needs for the teacher include:
 The actual Wheel Chair
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Proximity sensors for faster and easier navigation
Motors for motion: Servo motors for accurate motion, but DC can work for the particular case.
A wireless controller(Bluetooth Compatibility) such as the PS3 controller
A PLC such as the Arduino or even better a mini computer board like the Raspberry Pi
Energy Source for the pi: Since it’s not going to be a plugged in connection, an onboard battery
will be needed. Double A batteries might do the trick but will probably run out quickly so
rechargeable batteries that last longer might be the best option. Such batteries include Lithium
ion or other.
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System Configurability
HW Needs:
 Rasberry Pi
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o
SD Card
o
USB Bluetooth Dongle
o
Battery Pack
o
Power Wall Adapter
Gertboard
o
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Power Wheelchair (Fully Functional)
o
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Pi To Gertboard Adapter
Joystick (To Control Movement)
Ultrasonic Sensor (X4)
o
Sensor To Wire Adapter
o
Wire (X? feet)
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Wii Remote
o
AA batteries (X?)
The customer will send wireless commands to the wheelchair via Bluetooth using the Wii remote.
Commands will get processed by the raspberry pi, which will then control the wheelchair accordingly. The
gertboard, is the interface between the raspberry pi and the wheelchair’s motors will take an input voltage
from the wheelchair’s batteries, the pi will regulate the voltage thus controlling the wheelchairs speed and
direction. Alongside the wheelchair, there will be several proximity sensors for safe navigation. The user
will also have a joystick to direct accurate controls.
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