Final Paper

Projects for Nathan Lamb SmartKart

iHome Remote

Mobile Stander

Porch Swing

Group 2

Diana Manivong

Hunter D’Addeo

Saif Ejaz

Client info

Janice M. Lamb

142 Barnes Road

Stonington, CT

Phone: (860)-460-1394

Fax: (860)-245-5699

Email: Janice.lamb@linde.com

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Table of Contents

Abstract

1. Introduction

1.1 Background

1.2 Purpose of the project

1.3 Previous Work Done by Others

1.3.1 Products

1.3.2 Patent Search Results

1.4 Map for the Rest of the Report

2. Project Design

2.1 Introduction

2.2 Optimal Design

2.2.1 Objective

2.2.2 Subunits

2.2.3 Prototype

3. Realistic Constraints

4. Safety Issues

5. Impact of Engineering Solutions

6. Life-Long Learning

7. Budget

7.1 Budget

8. Team Member Contributions

8.1 Hunter D’Addeo

8.2 Saif Ejaz

8.3 Diana Manivong

9. Conclusion

10. References

11. Acknowledgements

12. Appendix

12.1 Updated Specifications

12.2 Other information

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Abstract

The main objective of these projects is to improve the quality of life of a 12 year

old with spina bifida, and autism, as well as cognitive and physical disabilities. The

current SmartKart was unsafe, and many of the mechanical and electrical systems did not

operate to full capacity. Current iHome remotes require a more complex understanding

of the layout of the iPod than our client could use. Mobile standers on the market are

currently either only available in a pediatric model and require the use of two hands, or

are the large motorized model, neither of which suit the needs of our client. Our client

also uses a glider rocking chair, but swings too vigorously and knocks it over.

In order to determine what the most effective designs for each of the projects

would be, we looked to the limitations of currently available products, as well as related

patents and iPod software. There were several patents for one-arm drive wheelchairs,

and there are several iPad apps that allow the user to control playlist output. As the other

two designs are modifications, less creativity will be required in the designs.

Nathan is aware of his physical position and is able to control where he

goes. However; the current SmartKart controls are too sensitive and the device is not

safe, he has outgrown his mobile stander and needs one that he can control with one arm,

he needs a porch swing to enjoy the sensation of movement without a constant

chaperone. He currently requires his parents to change the music on his iHome, and turn

off the lights in his room.

Our SmartKart design will fine-tune the device from last year; the smart-braking

system will be operational, the controls will respond more properly to user input, the

passenger side will have a steering wheel and brakes, and the shifting mechanism will be

in a more effective and convenient location than its current position behind the

passenger’s seat.

The iHome remote design will use current hardware along with software of our

design to make an iPad app that can control the output of the iHome. There will be 5

buttons, “pause/play,” a volume slider, and one for each of the three pre-programmed

playlists, making it easy to use and meeting the client’s specifications.

To make the proper mobile stander for Nathan, a one-arm drive wheelchair

mechanism will be mounted onto the existing frame. There will be harnesses, padding,

casters to prevent tipping; everything that a pediatric mobile stander has, only scaled up

to work for Nathan, while still fitting through the handicap accessible doorways in his

schools and in their house.

The porch swing design will take an existing porch glider swing and outfit it with

padding, harnesses, and casters. These modifications will make it more secure, so

Nathan will not fall out or tip it over, and the casters will allow the Lamb family to move

the swing inside when the weather is inclement.

Considering all of the necessary design specifications, as well as the $1000

budget, the team will design and create the mobile stander and iPad app, in addition to

modifying the SmartKart and the porch swing, in order to give Nathan some freedom of

choice and movement in his life, and give him experiences he can share with his friends.

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1.Introduction

1.1 Background (Client and disability) Our client Nathan Lamb, 12, was born with spina bifida, and has since been

diagnosed with slight autism and is developing scoliosis. He also has a shunt in his brain

to drain excess cerebrospinal fluid. Nathan is limited to only using his left arm. He keeps

his right hand placed to the right side of his head and often has spontaneous movement of

his head. He has poor trunk strength and is accustomed to being in a seated position. He

is usually supported by a car seat. These conditions make it difficult for Nathan to fit in

with his peers, as well as make it difficult for him to experience the pleasures of a boy his

age.

Spina Bifida is a birth defect involving the incomplete development of the spinal

cord or its coverings. The two forms of spina bifida are spina bifida occulta and spina

bifida manifesta. Most people who are born with spina bifida manifesta, like Nathan,

have hydrocephalus, which is an accumulation of fluid in and around the brain. The

symptoms of spina bifida can vary from nothing to severe paralysis.

Autism is a developmental disorder that affects the brain’s normal development of

social and communication skills. People with autism may be overly sensitive in sight,

hearing, touch, smell or taste. They may also have unusual distress when routines are

changed. They might perform repeated body movements and show unusual attachments

to objects. Nathan’s limited cognitive abilities make it difficult for him to communicate

what he wants, but he is still able to make certain decisions for himself. These projects

will not only allow Nathan to move around as he pleases, but will give him a greater

freedom to choose what he wants.

Figure 1. Nathan and Hannah, his sister

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1.2 Purpose of the project The purpose of these projects is to provide Nathan Lamb with an improved style

of living. They will allow him to have a greater amount of freedom. Nathan’s only means

of movement is his wheelchair at the moment. A working SmartKart gives Nathan a

chance to move around outside of his wheelchair at greater speeds. The mobile stander

will allow Nathan to move around at the height of his peers, which would give a new

perspective in his movement. Nathan only has use of his left arm, so it is necessary to

accommodate this in each of his mobile aids. This will give Nathan the opportunity to

have the control to move where he wants to move. Since Nathan cannot use the iHome

remote he currently owns, making a larger remote with distinctive buttons would allow

Nathan to choose the music he wants to listen to when he wants to. The porch swing will

be fitted with a restraint system to allow Nathan to enjoy swinging motions without

falling out or knocking the swing over.

1.3 Previous Work Done by Others

1.3.1 Products There are several projects that have been developed with the same objectives as

our own. The Recreational Electra-Scooter was developed in 1994 by a group of students

from the State University of New York. The scooter consisted of a wheelchair frame

attached to a plywood deck supported by an aluminum frame. The drive train was

powered by an electric motor while the steering assembly was located underneath the

plywood. It allowed the user to control when the motor would start and stop. The E-Racer

was developed in 2001 by a group of students who attended the University of

Connecticut, and was modified again in 2008. It was developed for a child who had

cerebral palsy and had greater control of his right hand. The team had implemented a

joystick steering system as well as a steering wheel. The driver could switch between

using the steering wheel or the joystick as suited. The overall cost of developing the E-

Racer was $1500.

Figure 2. The E-Racer

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In 2009, another group of students from UCONN developed the S90 Go

Kart. The S90 Go Kart was also developed for a child with cerebral and included the

possibility of the use of a steering wheel, joystick or steering wheel that the driver or

supervisor can switch anytime. Our design would be altering the 2011 SmartKart. This

was also designed by a group of students at UCONN. A joystick or an X-box controller,

depending on what the driver wanted, controlled the SmartKart. The SmartKart uses a

gas-powered motor and had an automatic braking system. The go-kart cost $4000 in total.

A project similar to our swing was proposed in 1995 by a group of students from

Burningham, New York. The swing was designed for a child diagnosed with cerebral

palsy who did not have control of his legs. The swing was altered so that the child could

move the swing with his arms and only seats the child.

In 2000, a group of students from North Carolina state University modified a

dynamic stander for a child with spina bifida. The group modified the dynamic stander to

be more comfortable for the child, which cost $268, but did not offer control of the

standers movement to the child. Our modifications would allow the driver to control

where they wanted to go.

Mobility 4 Kids, a commercial company that manufactures mobile aids for

children with disabilities has developed a go kart and a “sit to stand” mobile device. The

“sit to stand” mobile device changes from a wheelchair to a mobile stander. The child can

control the his movement through a joystick. In addition, they also manufacture an

electric powered go-kart. Like the “sit to stand” mobile device, the go kart can be

operated with a joystick. Another company, Quest 88, takes Berg manufactured go-karts

and alters them in order to accommodate the needs of those with disabilities. These

include adding harnesses and foot pedals or modified steering wheels.

Figure 3. The Smart Kart then

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1.3.2 Patent Search Results Currently the only patent for a mobile stander would be the User-propelled

seeking apparatus (patent no. 5,732,964), patented in 1998 by a group of inventors for

Magic Walker, L.C. in Jackson, Mississippi. The stander is user-propelled; it uses a gait

guide system and the user’s legs to propel the rear wheels, while the front wheels can be

steered. The apparatus can have a seat or be adjusted for standing.

The most recent patent for a go-kart that could accommodate people with

disabilities was patented by Keith Alan Roberts and was called the Handi-driver.

Patented in 2002, the Handi-driver had included the braking system and the throttle into

the steering column, which allowed those limited to the use of only one arm to drive the

go-kart. In addition, a kill switch was added to the steering column in case of

emergencies. The Handi-driver utilizes brake pedals and a a throttle lever similar to those

found in motorcycles attached to the steering apparatus.

1.4 Map for the Rest of the Report The rest of the report will include the initial alternative designs and then the

optimal designs that select the best design out of all of the preliminary designs, in

addition to taking advantage of features from the other designs. The optimal designs for

each project will be broken down into subunits that describe the major components of

each project. Afterward, the prototype design for each of the projects will be listed and

discussed in detail. Next, the realistic constraints will be discussed, which encompasses

engineering standards, economic, environmental, sustainability, manufacturability,

ethical, health and safety, social, and political considerations. Safety issues will also be

discussed, followed by the impact of engineering solutions. Life-long learning

accomplishments that will be achieved from carrying out this project will be discussed

after than, which will in turn be followed by the display of the budget and timeline.

Contributions of all the team members mapped out, and then the conclusion, references,

acknowledgements, and the appendix will follow.

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2. Project Design

2.1.1 Mobile Stander The goal for this project was to modify an existing stander, provided by the

school to suit Nathan’s needs. However, the school does not want their stander damaged,

so a new stander will be constructed based on the original stander, scaled up to

accommodate Nathan’s growth. Each design will use the same frame, but will be

controlled by a different means, but since Nathan only has full use of his left hand, the

stander will need to be propelled by some form of one-arm drive.

The universal design will utilize four casters, two to the front and two to the back,

as a stabilization mechanism. They will provide sufficient support to prevent capsize,

and do not impair the movement of the user.

The mobile stander will have foot stands as well as padding for the legs, hips and

torso. An adjustable strap harness system will be implemented to keep the client in

place. The stander will also have a retrofitted seat from Nathan’s previous mobile

stander for when he would like to sit, as well as for additional support. There will also be

a tray for Nathan to use for art, books, eating, or homework.

2.1.1.1 Design 1: Double Hand-rim Mechanism The first design will be a mobile stander with a mechanical one-arm drive. The

driving mechanism will be on the left wheel to accommodate Nathan’s sole use of his left

arm. The mechanism will be a double hand-rim system, and for propulsion, gripping one

rim will turn the wheelchair left or right, while gripping both will propel the wheelchair

forward or reverse. Most current designs of this mechanism that are on the market are

designed for folding wheelchairs, but can be implemented without a problem.

One potential problem for this mechanism will be finding a one-arm drive wheel

set that is large enough for Nathan to be able to grasp the hand-rim comfortably while he

is standing in the device, as most existing one-arm drive wheels have a maximum

diameter of 26 inches. Additionally, turning both of the hand-rims at the same time or

stopping both of the hand-rims once the chair is in motion, will require a fair amount of

grip strength, which may render this design unusable for our client.

2.1.1.2 Design 2: Lever Drive Mechanism The second design also uses a mechanical one-arm drive. The driving mechanism

will be implemented through a lever. The lever will be connected to the front casters as

well as have connections to the rear wheels. The lever will have neutral, forward, and

reverse settings. In the neutral setting the wheelchair can be pushed by a caretaker. In the

forward and reverse settings, the lever can be pumped forward and back to move in the

set direction. The lever also has two grip-brakes, similar to a bicycle, which will allow

the user to steer and stop. To turn, one of the brakes must be gripped, and that will

impede the motion of one of the wheels, causing the device to turn. To brake, the lever

would have to be set in the neutral position and pulled back to lock the wheels, or both

brake levers compressed. This model will be using the same general design as the

previous model as it will have the same restraint system as well as padding, foot stands,

and holding tray.

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The brakes will be simple disc brakes, as used on a bicycle. The wheels will be

attached to the axle via a ratcheting mechanism set to a fairly low torque, so when the

brakes are implemented, the wheels will not turn, and will not put unnecessary wear on

the brake pads.

One possible problem for this design will be in the user interface. The lever

controls are not as intuitive as the wheel-based hand-rim design. However, the force

required to propel the device is less, as well as the grip strength required to manipulate

the controls.

2.1.1.3 Design 3: Electric Power-Stander The third design will use a motorized one-arm drive. A joystick will be used to

propel and steer the rear wheel drive stander forward or in reverse. For steering, one of

the rear wheels will be fed less power, causing it to turn at a slower rate. There will also

be a lever on the joystick when Nathan wants to slow down or brake. There are current

designs on the market that fulfill these requirements with minimal modifications.

The mobile stander will use two electric motors to propel itself, one mounted on

each of the rear wheels. A deep-cycle battery will power the device, so it will be

rechargeable and maintain a charge for a longer period of time.

The biggest problems with this option would be affordability and mobility. The

electric standing chair is much heavier than the mechanical designs will be, and even

before modifications is likely to cost much more. Since the chair is so heavy, it will not

be as portable as the clients would need it to be.

2.1.1.4 Conclusion Since Nathan is limited to using only his left arm, the mobile stander must be able

to move by a one-arm drive. For the one-arm drive, a lever-drive mechanism will be

implemented. The lever-drive design will be used instead of the double hand-rim because

the double hand-rim design would require us to find a one-arm drive wheel set that is

large enough for Nathan to be able to grasp the hand rim comfortably while standing in

the device. This would be difficult since most existing one-arm drive wheels have a

maximum diameter of 26 inches. Another problem of the double hand-rim design would

be the amount of grip strength needed to turn or stop the hand-rim, which may make the

device unusable by Nathan. The grip strength and force required by the lever-drive design

is much less than that of the double hand-rim. We chose the lever-drive design over the

electric powered, motorized joystick design because it is lighter and more affordable than

the electric design. Since it is so heavy, the electric powered design would not be as

portable as the clients would like it to be.

2.1.2 SmartKart The goal for this project is to fix last year’s design. A majority of the problems

that need to be fixed are electrical, or need to be determined by further testing once the

kart is on-premises. One of the client’s higher priorities was to make the turn radius

much smaller; it currently takes more space to turn around than is available for it to drive

in.

2.1.2.1 Design 1: New Rack and Pinion

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This design will replace the current rack and pinion setup that is in the Kart. The

existing setup only has a 3-inch swing; with a larger setup it can swing 5 inches

total. This way, when the user inputs a full left or full right turn, the wheels will actually

turn further on their axes, making the turn radius smaller. The same turning motor and

speed controller will be used, only the programming will have to be changed to

accommodate for the larger setup.

This design poses a few problems, one being the adjustments to the frame that

would be necessary to insert and stabilize the setup. The initial frame was built to fit the

current devices, and tinkering with the frame could cause stability issues further along in

the project. Also, with a larger setup, there is the possibility for interference with the

turning axles of each wheel. The rack and pinion, if not properly positioned and tested,

could damage other existing parts.

2.1.2.2 Design 2: Adjusting Turning Axles This will be the simplest option. The current turning device is attached far from

the center of the turning axle in order to deliver the most turning power. However, this is

not an issue. Positioning the device interface closer to the actual wheel will increase the

turning ability of the kart without excess replacement of parts or manipulation of the

initial design.

The main problem with this design is the possibility of damaging the turning axle

setup in the testing phase. With the rack and pinion setup mounted closer to the turning

axle of the wheels, each inch of linear displacement will cause a higher degree of

turning. This may pose the same problem as the larger rack and pinion setup, but will be

easier to compensate for, as the frame already accommodates this size device.

2.1.2.3 Design 3: Shortening the Frame As the length of the wheelbase of a vehicle increases, the turning radius will also

increase. Since the original go-kart that was modified had a shorter frame than the

current prototype SmartKart, the turning radius was not an issue, and the little turning

ability that the wheels had was enough to make the kart maneuverable.

A possible solution to this would be to shorten the frame back to what it once

was. This will make the kart lighter, faster, and allow for heightened

maneuverability. This will pose several problems, however. The SmartKart was already

taken apart and put back together once. Taking it apart and reassembling it once more

will exponentially increase any structural problems that may exist but are not apparent

thus far. Additionally, making the kart smaller will decrease the foot-room available for

users, which, once the brake and throttle pedals are added, will impede their ability to

control the kart to the best of their ability due to discomfort.

2.1.2.4 Conclusion The adjustments to the turning axles were selected as the most viable option in

correcting this issue with the SmartKart. Out of all the options, it is the most cost-

effective, it causes the least destruction to the existing frame, and it allows for the users to

remain comfortable, which would be an issue with shortening the kart. Moving the

interface within 2 inches of the center of the turning axle will cause the wheels to turn

another 15 degrees in either direction, and since they only turn

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2.1.3 iHome remote The purpose for this project is to design an iHome remote Nathan can properly

use to change music in his iPod as well as turn the lights in his room on and off. The

remote itself will have large, color-coded buttons so that Nathan can choose what he

wants to do. Per the client’s request, the remote will be large enough for Nathan to use.

The remotes will be around an 8” x 6” in size and made from a durable a relative Two of

the designs will be using a physical remote. The third would be using an iPad app.

2.1.3.1 Design 1: Wireless Remote This design will be using multiple Bluetooth chips to communicate between the

remote, the iHome, and the light switch. The Blue tooth micro-controllers would have to

be programmed to effectively communicate with the iHome as well as the augmented

light switch in Nathan’s room. The blue tooth micro-controller would also be physically

wired to Nathan’s iHome, in order to communicate with the device and the iPod.

This design specifically meets what the client wants. It would be enough so that

Nathan would not break it and would be easy enough for him to use. The main problem

is that this would not only be the most time consuming option, but also the most

expensive. The programming would take up time that can be used to ensure that the other

projects will meet the client’s needs.

2.1.3.2 Design 2: Wired remote In the second design, the remote will not be wireless. A physical wire will connect

the iPod remote to the iHome. This will increase ease with which the remote will

communicate with the iHome, as we will not have to spend as much time coding a wired

transfer of information. However, the part of the remote that controls the lights will still

be wireless.

Some problems with this design include the portability of the remote and the

difference between the product and the client’s specifications. The remote would only be

able to go as far away from the iHome as the connecting wire is long, and once the wire

is taut, any excessive movement of the remote could cause the iHome to fall off of the

dresser upon which it is currently situated. Furthermore, the wire would be a safety

hazard, as it could cause someone to trip, or it could wind around someone’s neck were

they not being careful.

2.1.3.3 Design 3: iPad app Our clients told us it would be a possibility to write or find an iPad app to control

the music and lighting in Nathan’s room. He already uses the iPad, and there are already

means available to easily have wireless communication with the iHome, such as the

Airport.

With the iPad and Airport wirelessly networked, the user can choose the Airport

as the audio output for the iPad. The Airport has an auxiliary cable port, which could be

used along with a 3.5 mm stereo male-male cable to connect it to the iHome. This would

make the iPad control the output of the iHome.

Additionally, there are currently apps that allow the user to interface with

household devices, such as light-switches, televisions, etc. Using these apps as a guide,

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as well as purchasing the requisite light switch, would make the iPad function as a remote

light-switch.

The program interface would resemble the remote design with three buttons to

coordinate playlists, one button to start and stop the music, and one button to turn the

lights on or off. Since there are fewer parts and less fabrication needed in this design,

more time could be spend on coding, and more money could be spent on other projects.

2.1.3.4 Conclusion The iPad app was chosen as the optimal design over the wired and wireless

remotes. The iPad app would be used on an iPad that Nathan’s parents already own.

Nathan has used the iPad before, so he will be familiar with the product and it will

ultimately be easier for him to use the program. The iPad app fulfills the client’s request

to have a wireless remote to control the music and lights in the Nathan’s room. The

provided iPad will also make it easier during the testing phases of the project once the

app is finished. In addition, the provided iPad will eliminate the need to spend an

unnecessary amount of money on the components for the remotes.

2.1.4 Porch Swing The main objective of this project is to design a swing for Nathan to use. The

client informs us that Nathan desires movement, but rarely gets the chance to do so. The

swing will be designed taking the client’s house into consideration, as when we met with

them, the ability to move the swing into the house was greatly desired.

There will be three different designs with varying modifications regarding the

frame holding up the actual swing. The bench of the swing will be the same for all three

designs and will be able to seat two or more persons. The seat will be reinforced and

padded to accommodate our client, and part of the seat will have a harness so that Nathan

can swing safely without falling out and risking injury.

2.1.4.1 Design 1: Ceiling Swing The first design will have the seat attached to the ceiling of the deck by chains

that connect to the bottom of the seat. On each side, two chains would converge to a

single ceiling hook. The ceiling hooks would be attached to the I-beams in the roof of the

deck. The chains would be able to support at least 400 lbs. of weight.

Although this would be the easiest to implement in theory, there are still a few

problems with the design. One being mobility; with this design the client will not be able

to bring the swing inside. Since the swing would be attached with chains, there will not

be anything to keep the swing secure at rest. This could make it difficult to put Nathan in

the swing.

2.1.4.2 Design 2: Glider The second design will be similar to a glider chair or sofa. The seat of the swing

will be attached to the base through a double rocker parallelogram 4 bar linkage. To

provide a rocking or swinging motion, the glider will be using non-parallel suspension

bars, which will simulate a rocking motion. The glider will be on casters in order to

conveniently move the glider from the deck to inside the house. Additionally,

telescoping supports would be attached to the base, giving the device more stability when

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deployed, and when retracted the bench would still be small enough to fit through the

doorway.

The main problem with this design would be with the stability of the glider. The

glider will exert a lot of force on the supports we add, which will make it difficult to find

the proper material that is light enough but can resist relatively high loads. In addition,

the range of motion would be the smallest with this design. Out of all designs, this seems

most feasible.

2.1.4.3 Design 3: A-frame Swing The third design will be more of a conventional swing. Like most swings, it will

have an A-frame to support the swing. The bench will be supported in the same way the

ceiling swing would be supported. Instead, the ceiling hooks would be attached to the

main horizontal support beam.

The problems of this model are very similar to the problems with the ceiling

swing. Although it is not attached to the ceiling, once this design is assembled, it will be

very difficult to move around. Essentially it will be stationary. In addition, since chains

suspend the swing, it will be more of a hassle to put Nathan into his seat and secure him.

2.1.4.4 Conclusion The glider was chosen over the two other porch swing options due to its

portability. Since a glider can be moved inside or outside, it will be usable during

unfavorable weather conditions, increasing the use our clients get from the swing. The

ceiling-mounted swing would require a majority of our construction time installing it to

the ceiling of the porch, and would not be as usable as the glider. The A-frame based

design would fit on the client’s porch due to the height and width of said porch being

larger than average, but it would take up a lot of space, and would not be usable during

poor weather.

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2.2 Optimal Design

2.2.1 Objective

2.2.1.1 Mobile Stander The goal of this project is to take an existing mobile stander and modify it to fit

Nathan’s needs. The design will use four casters, two in the front and two in the back, for

stabilization of the device. These casters will prevent any capsizing and will not impair

movement of the mobile stander. Also included in the design will be a tray for Nathan to

use for art, eating, books, or homework. Along with the tray, the stander will have a

retrofitted seat from Nathan’s old stander in case he may want to sit, as well as for

additional support. The stander will need padding for his chest, arms, and hips. In

addition, the stander will also be using an adjustable harness system to secure Nathan.

The stander itself will need to last for all of Nathan’s middle school and most of

Nathan’s high school career. Therefore, it will be necessary to make the supports

adjustable so that Nathan can use the mobile stander as he grows older.

Since Nathan is limited to using only his left arm, the mobile stander must be able

to move by a one-arm drive. For the one-arm drive, a lever-drive mechanism will be

implemented. The lever will be connected to axle, which will be propelled with a simple

gearshift drive. As the lever is pushed or pulled, depending on the current gear, the

stander will move forward or backward, respectively.

The steering mechanism of the mobile stander is based on rotation of the drive

lever. As the drive lever is twisted left or right, the mobile stander will turn left or right,

respectively.

The brakes of the mobile stander will be simple caliper brakes like those used on

a bicycle. The right wheel will be attached to the axle by a clutch mechanism attached to

the brakes. The brake will prevent the right wheel from moving while engaged, and if the

stander is in gear, it will not move.

2.2.1.2 SmartKart The purpose of this project was to fix the problems on last year’s smart kart

design according to the client’s requests. The previous year’s team had implemented a

joystick control, in case the client wanted Nathan to steer the kart and was designed to

seat two people; the driver of the kart and Nathan as a passenger. Nathan’s seat uses a 5-

point harness system to keep him in place. Nathan’s father had informed us that not only

was the harness system difficult to use, but putting Nathan into and taking him out of his

seat was also a hassle.

The Kart uses a joystick and wired Xbox 360 controller for steering. The user can

choose whether they want to drive (Xbox controller) or Nathan to drive (joystick) via an

interface on the dashboard. The clients had complained that the Xbox controller “did not

work well” in that it did not reverse or steer well. Given this problem, the Xbox controller

was replaced by a steering wheel attached to a rotational potentiometer, which will

function like a power-steering system in a car. The driver’s side will also have a uniaxial

joystick as a throttle/braking mechanism. In addition, a new joystick was used on

Nathan’s side of the Kart, as the existing joystick was falling apart. The smart braking

system had to be removed, as it was impossible to get the voltage and range attenuated to

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make it function within the proper range specifications. The programming and the

mechanical alignment of the steering system had to be realigned to correct the turning

radius and allow for different ranges of turning capacity to be reached.

One major problem of the Smart Kart was that it could not be used in wet

conditions, even if it was not raining during use. This was because the components were

not properly packaged; wires were poorly bundled, and compartments with electronics

were not completely sealed. The new design will feature panels that will protect the

electronics from moisture-related damage.

2.2.1.3 iPad App The purpose of the iPad is to develop some means for Nathan Lamb to control his

iHome as well as the lights in his room remotely, as he cannot reach either of them from

his bed. The remote must be capable of changing the playlist that is being played by the

iHome, and there are currently no remotes that both allow the user to change playlists and

are user-friendly enough for Nathan.

One of the commercially available components will be the Apple Airport

Express. The advertised function of this device, “Airplay,” allows the user of an iPod or

iPad in wireless range to choose to play their music directly from the Airport, as opposed

to the integrated speakers in the iPod itself. We are using “Airplay” for our design,

eliminating the circuit building and programming that would have been central to the

other two designs.

The light controller had to be dropped from the final design, as integrating the

components from another set of hardware into the existing Apple interface code

presented more of a challenge than originally anticipated.

The Airport will be configured to the client’s home network, as well as the

client’s iPad, which will allow the iPad to output music through the iHome speakers.

2.2.1.4 Porch Swing In order to further fulfill Nathan’s desire for more movement, we will also be

augmenting a porch glider so that Nathan can safely enjoy the swinging motion. The

glider is portable so that it can be used both inside and outside of the house.

The glider will be able to seat two people comfortably and will use a simple lap

belt along with a chest belt in order to keep Nathan secure in his seat. The seats are

cushioned for additional support and comfort, a necessity due to Nathan’s reduced trunk

strength and lack of posturing. In addition locking, swiveling casters support the glider.

The casters will allow the glider to be moved in and out of the house when needed, and

can be locked to prevent any unnecessary movement. The casters are mounted with

struts to the bottom inside of the glider’s frame, allowing for increased support and

minimizing the chance of failure with repeated use.

2.2.2 Subunits

2.2.2.1 Mobile Stander

15

We will be using an existing mobile stander, to be provided by the Stonington

School district. We will also retrofit as many parts from the mobile stander Nathan has

previously outgrown as possible.

Drive Lever and Mechanism The drive lever will be made of hollow aluminum tubing with two cable-brake

grips attached. These brake cables will control the braking as well as the steering of the

mobile stander, as described in the introduction. The idea for using this mechanism came

from an old Design News article that demonstrated how a cable drive around an

expanding clutch collar can provide unidirectional propulsion without too bulky of an

assembly.

Figure 4. Drive Mechanism

Figure 5. Hand-Brake System

16

Braking Mechanism The brake levers from Fig. 7, shown above, will use a combination clutch-braking

system to allow for heightened maneuverability. As each brake lever is depressed, the

brake calipers on their respective wheels will clamp down and the drive clutch on the

wheel will be engaged. This will allow Nathan to make turns of variable angles, all with

one hand. The idea for this design was found as part of patent number 6224078, Steering

arrangement for an occupant propelled vehicle.

Steering Caster and Mount

The steering caster was part of the setup purchased form the NEAT Marketplace.

There is a small joint that connects to the bottom of the lever drive on one end and

connects via a pin to the caster. A mount had to be machined

2.2.2.2 SmartKart We will be using the existing SmartKart to start with. The seating area inside

the kart is already widely expanded to accommodate two passengers, elongated to

provide more leg room, and contains additional supports for Nathan. The dash allows the

passengers to decide which mechanism will be used to drive; the joystick or the Xbox

controller. Nathan’s seat is very well padded, and has an adjustable headrest to

accommodate any growth.

Turning Axles The clients expressed that they wanted the kart to make tighter turns. In order to

do this, we will be attaching the rack and pinion turning mechanism closer to the turning

axle. This will effectively lower the turning radius of the kart.

Figure 6. Clutch-Braking Mechanism

17

Driving Mechanism The existing Xbox 360 controller will be replaced with a conventional steering

and pedal system. The steering wheel will utilize the potentiometers used in the Xbox

controller. The stainless steel pedals will be fashioned into the throttle and brake

assemblies and will be used as switches. Duty cycles will be used in order to effectively

emulate acceleration and deceleration.

Harness The clients stated that they were having difficulty operating the existing 5-point

harness. The replacement will be a 5-point cam lock harness shown in Fig. 4. This type

of mechanism differs from the Latch-Link mechanism in that there are simply 4 buckles

that clip into a single spot, rather than three “links” that go around the “latch,” and go

into a buckle at the end. This harness will be just as safe for Nathan, and will be easier to

get him into and out of.

.

2.2.2.3 iPad app The design for this project will consist of three elements; the iPad app, the Airport, and

the PLCBus switch. The iPad and the iHome are currently owned by the client, and will

not be needed for the initial design process, though they will be used during testing.

iPad App Interface The app will be created with Objective C via Microsoft Visual Studio. The layout

will be simple; 3 buttons will pick which playlist is being played, one button will function

to pause or play the music, and one button will control the lights. The playlists currently

correspond to Nathan’s musical appetite, as described by our client.

Figure 7. Five-point Cam-lock Harness

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Airport The Apple Airport will function as a wireless receiver for the iPad. Once the

Airport is selected as the audio output from the iPad, whatever music that would be

played from the integrated speakers is instead transmitted through the stereo jack, which

will be connected to the iHome.

PLCBus Module

PLCBus are the most common wireless electronic switches for household

purposes. The model PLCBUS-R-2263HE is a single load heavy duty version of this

switch, and is able to be easily installed in a wall switch junction box. These are

Figure 8. iPad App Interface

Figure 9. Apple Airport Express

19

compatible with existing iPad apps that allow for the switching of lights on and off, so

compatibility will not be an issue.

2.2.2.4 Porch Swing This project will be a modification of an existing glider bench, fitting it with

casters, lap-belts, cushions, and supports. Additional reinforcements may be necessary to

allow the wooden frame to endure more vigorous swinging or other dynamic loading

conditions.

Casters The bench will be mounted on additional supports with casters. Since traction

and maneuverability of the bench will not be too large of an issue, the swivelling, locking

casters we found in the lab will work. The casters will be mounted on hinged blocks with

Figure 10. PLCBus 2-Appliance Module

Figure 11. Porch Glider Swing

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a locking mechanism as shown below in Fig. 12. As the handle (upper crosshatched part)

is gripped, there is tension exerted on the cable. The cable is wrapped around pulleys,

and then will pull the locking pin out of the caster mounting block.

Restraints and padding A simple lap belt will be used for restraints in this case; there will not be too large

of a risk of injury from using this glider bench, and a two-point harness will provide

sufficient protection. The bench will be intended for two users at a time, and as such will

be equipped with two lap belts. Additionally a memory foam cushion will be made to fit

the seat of the bench. The cushions will be encased in polyester, which will not be

waterproof but will be easy to clean and maintain. The cushions will be removable to

allow cleaning of the device under where the cushion would be.

Figure 12. Casters with Mount and Locking Mechanism

Figure 13. Memory Foam Padding and Safety Belts

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2.2.3 Prototype

2.2.3.1 Mobile Stander

The mobile stander was provided by the Stonington school district. Nathan had

outgrown it, and due to his ability to only use his left arm, was unable to control the

stander in an effective manner. Our modifications made the stander able to accommodate

Nathan, making it taller and drivable with one arm. Modifications were made to our

original optimal design as well.

Drive Lever and Mechanism The drive lever is made of hollow steel tubing with a horizontal rubber

grip. Pumping the drive lever propels the stander, while twisting the lever in either

direction causes it to turn. A one-arm drive mechanism from a wheelchair was purchased

from the NEAT Marketplace, and was increased in size, as well as modified with

additional parts to allow it to fit the mobile stander.

Figure 14. Completed Mobile Stander

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The parts that had to be custom fit to the drive lever and mechanism include; pins

and a large bushing to fit between the existing wheel and the drive gear, a large plastic

spacer to maintain distance between the frame of the stander and the wheel, a custom bolt

to properly fit the new mechanism and the wheel, and a hollow steel tube with the

modified bracket from the original design.

Figure 15. Extended Drive Arm

Figure 16. Drive Mechanism and Drive Wheel

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Steering Caster and Mount

The steering caster was part of the setup purchased form the NEAT Marketplace.

There is a small joint that connects to the bottom of the lever drive on one end and

connects via a pin to the caster. A mount had to be machined to fit a bushing that would

hold the caster in place, but would allow it to rotate freely.

Main Shaft Extension

The main shaft was extended with ¾ inch aluminum square tube stock. Since the

existing shaft was made of steel, the connection between the top of the shaft with the

bracket for the chest pad and elongation was done with a bolt, rather than a weld. This

attachment increases the maximum extension of the main shaft by over 18 inches, which

will more than compensate for Nathan’s recent and projected growth.

Figure 17. Steering Caster and Mounting Bracket

Figure 18. Extended Main Shaft

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Hip Pad Replacement

As the current hip pads were meant for a smaller child, new hip pads, found from

Machine Shop stockpiles, were fitted to the existing bracket. The new hip pads will

provide more support and can be moved up the new main shaft. The bracket for the hip

pads was modified with aluminum stock to make it fit onto the extended shaft, as it was

previously intended to be mounted onto the lower central frame of the stander.

We were able to mount the pads to the bracket using the original allen screws.

Threading the metal backing of the pads was difficult due to the relatively small thickness

of the metal compared to the depth of the threads, but after testing, the threads proved

sufficient.

Testing

Saif and Hunter tested the mobile stander with and without a person standing on

it. Without a load, the stander does not exert enough force on the front caster to keep it

stable. With too heavy of a load, the turning ability decreases and the force required to

propel the stander increases. Given that our client does not weight as much as any person

in our lab, the issue should be resolved.

The large wheels on either side must be left in their current position or the stander

will not be stable. Additionally, the foot plate must be projected backward slightly to

properly distribute the weight among the six wheels; otherwise, either the drive wheel or

the steering caster will not be subject to enough friction and will cause that system to fail.

Figure 19. Replacement Hip Pads

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2.2.3.2 SmartKart

The previous year’s Senior Design Team 9 provided the SmartKart, and many

modifications were made to make the kart more accessible, easier to control, and less

likely to be damaged with weather. The turn radius was also decreased, as per the

specifications of the client.

Turning Radius Correction In order to correct the turning radius, many ideas were entertained, including

replacing the rack and pinion, elongating the shaft on which the wheels were fixed, of

just changing the programming. In the end, mechanical adjustment was all that was

needed, along with a slight change in monitor values in the steering code.

A new hole was drilled onto each of the “turning axles” approximately 1 inch

closer to the axis, which translated into a 50% increase in turning on each wheel, giving

the wheels much more variability.

In addition to drilling the holes, once the wheels were attached, the entire front

end was reconstructed to compensate for the increase in turning ability. Starting from

scratch, it was easier to make the wheels properly aligned.

The monitor was measured for each new final turning position of the front wheels,

and those potentiometer values were used in the steering code.

Figure 20. Turning Axle Modification

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Digilent - Arduino Board

For two months in the spring semester, we attempted working with the previous

design team’s circuit board images to configure a new board for our kart. However, due

to incomplete information, the changes that the previous team made to their board, and

the time constraints, we decided to get an Arduino compatible board. The Digilent

MAX32 was found after some searching, and we rushed to get the board programmed,

though we did have an advantage of having the previous pin-outs and code to give us a

leg up.

The board boasts 83 I/O pins, and with its 32bit 80kHz processor, it was more

than capable of handling the computing for the SmartKart. The incorporation of existing

Arduino libraries simplified the code, as well as the differences from C programming to

Arduino. Defining input pins was also simpler with Arduino, as the code only calls

“pinmode (A0, INPUT);” and still uses “for” loops and “while” statements.

We also took advantage of another feature in the Arduino libraries, the ability to

map the values of the potentiometers and actuators. This improved the attenuation of the

steering, as in the previous design there were only absolute values for turning; left, right,

and neutral. The new code segment will make it so slight adjustments in the joysticks

correspond to slight movements in the steering, throttle, and braking.

Figure 21. Digilent chipKIT MAX32 Arduino Board

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Harness Replacement

As per the client’s specifications, the harness was replaced with another that was

much easier to use. The cam-lock harness that we purchased uses belts similar to a

seatbelt, and both attaches and detaches much more easily than the latch-link harness that

was on Nathan’s seat previously.

Figure 22. Initial Arduino-based Code Segment

Figure 23. Remix Custom 5-Point Harness

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Xbox Controller Replacement

As above, a feature from the previous team that the client requested to be replaced

was the Xbox Controller as a steering device for the passenger side. Nathan’s father

Harvey said that the controller was awkward and difficult to use, so we replaced it with a

steering wheel and a throttle joystick.

The steering wheel was found in the stockpiles of the machine shop, and we

augmented it to make it fit the SmartKart and contain the rotational potentiometer.

The rotational potentiometer from RadioShack has 10k Ohm resistance, as did the

previous potentiometers from the Xbox controller, according to Cameron Fulton’s circuit

schematics from last year. It has a 300 degree turning range, and has threads at the base,

which allow us to construct the complete steering mechanism.

Figure 24. Steering Wheel

Figure 25. Rotational Potentiometer

29

The APEM 4000 series uniaxial joystick shown below is the new throttle

mechanism. In one of our preliminary designs, the throttle was going to be based on the

propulsion of a boat. We adapted that idea to a joystick, and since the steering wheel can

be operated with one hand, the free hand will be used to operate the throttle.

Joystick Replacement

The existing joystick on Nathan’s side of the SmartKart was falling apart and was

not sound in its construction. We purchased a new APEM 5000 series biaxial joystick to

implement, and will be using a similar setup to last year’s design. This joystick is more

sensitive than the previous one, and as such will be damped in the code to reduce the

probability of injury in our client.

Figure 26. Uniaxial Joystick

Figure 27. Biaxial Joystick

30

Ultrasound Braking Removal

Due to the configuration of the Ultrasound system, it would not be possible to

implement that mechanism. After reading the previous year’s reports, as well as the

manuals for the components, we found that they had already damped down the voltage to

reduce the signal range of the sensors. Additionally, the sensors perceive a cone in the

direction in which they are aimed; aiming the sensors away from the ground at all would

cause them to not register any objects, and would render them useless.

Figure 28. The SmartKart Now

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2.2.3.3 iPad App

For the design and programming of an Apple app, it was necessary to use a

Macintosh OS. Dr. John Enderle allowed us to use his MacBook Pro for that purpose.

The Apple Developer program Xcode version 3.2.1 was used, as the MacBook OS Snow

Leopard is not compatible with the newest version of Xcode. The remote light switch

function of the application had to be culled from the prototype design as only one Mac

computer was available, and incorporating that would have taken more time than could

have been spent this year, which would have negatively impacted the other projects.

Interface Code

The interface in Xcode 3.2 is constructed with a helper program, “Interface

Builder.” The builder uses a library of actions, buttons, sliders, and identifiers to make

an .xib file. The .xib file is then imported into the Objective C code through a series of

connections, identifiers, and class references that steer the app into generating the image.

The button at the top left is the pause/play button, which updates itself based on

what playback states the iPad is currently experiencing. With the pause/play button

integrated into the Navigation bar at the top of the page and the volume slider of small

size, the three main features of the app are the playlist selector buttons. The colors of the

Figure 29. iPad App Interface Screenshot

32

buttons correspond to the main identifying color of the theme characters of the three

playlists as well.

App Initialization

Xcode and Objective C in general utilize multiple header and operational code

segments to organize data and prevent the segments from becoming overly lengthy and

unwieldly. There exist an “AppDelegate” series of files, the header and the operational

segment in which the “ViewController” segment is initialized and tied to properties that

identify it as the code that controls the subsegments of the UI.

In this case, the AppDelegate file imports the two headers and sets itself as a

class. The window and viewController variables are declared in the AppDelegate header

and are synthesized, allowing them to be used in this segment of code. The next segment

checks the state of the user interface, and if the app’s basic view is loaded, it projects the

.xib file onto the basic view, or in other codes, will generate a view directly from the code

or a pre-existing library. In the next segment, dealloc de-allocates the window, as that

was a global variable, and releases all other code segments, allowing the code to end.

Setting the Media Player

One of the conditions that any code that has sound requires is a check function

that finds a Boolean variable generates earlier in the code. Since this app uses the iPod

music player, the variable is set to on at all times. It then enables the navigation bar item,

the pause/play button, to “play” if the music is paused, and “pause” if the music is

playing.

Figure 30. App Initialization Code

33

Button/Playlist Filter Code

The segment of code that had the most ingenuity involved was the code that tied

the user interface buttons to a series of actions that allowed a single button push to search

the music library for playlists with a certain name, in this case “Elmo.”

Figure 31. Code to Initialize the Music Player

34

The code queries the library, making an array of all of the playlists in the library

and all of the songs that belong to each playlist. It then checks the current playback state,

and if the music is stopped, paused, or playing but with a different playlist than the one

specified in action, it then adds to the music player queue all songs in the playlist, and

begins playback.

Testing and Submission to Apple Since the app was in the development stage until very recently, the only testing

that could occur was the demonstration of the Airplay feature, and virtual simulation of

the app.

One of the features that touch-screen Apple products share is access to immediate

wireless network devices. Since the Airport is either its own network or tied to the

household network, if the iDevice is allowed to access the network, it can send its output

to the Airport instead of its speakers. This “Cloud Computing” trend that recentralizes

data, along with recent high wireless communication speeds, allows for near-immediate

transmission of media and other data.

The Airplay feature of an iPad was tested at Hunter’s house, checking for

playback and volume control. Both were successful, with one caveat; if the Airport is

being used as an output for a different device, that device must surrender control of it

before it can be used by another device.

The simulator, along with the debugging console, provided the testing for the iPad

app interface and code. Since all warnings and errors were eliminated, including the fatal

SIGBART error in debugging, the only errors that the code generates are due to the fact

that the simulator does not have, and therefore cannot detect a Media Library from which

to generate the arrays of playlists and songs.

Figure 32. Code That Runs When A Playlist Button is Touched

Figure 33. Selecting the Airport as the Output

35

2.2.3.4 Porch Swing

The porch swing was purchased online and assembled in lab. Using wood and

fittings purchased by Hunter and Saif, the swing was modified to use casters. Harnesses

found in the stockpile, as well as from the NEAT Marketplace, were attached also.

Figure 34. iPad Simulator Screenshot of Remote App

36

Reinforcement

As we found out when it arrived, the glider was “more than some assembly

required.” When all of the parts were put together, the glider’s bench was still very

flimsy. With 2 1x4 #2 pine planks, we had enough wood to reinforce the bench and

create the caster mounts and struts. The boards were fastened at points deemed to be the

most load-bearing, and since they will be covered with memory foam padding, their

protrusion from the body of the bench was not going to impact the comfort of the user.

Casters, Mounts, and Struts

The casters used in this design were salvaged from the stockpiles in the Machine

Shop. There were two pairs of matching casters, so one pair was used on the front of the

bench, and the other pair on the rear. Minor adjustments were made in the mounting

process to make the base of the glider level.

In order to attach the casters in such a way that they would not protrude from the

body of the glider, interfere with the swinging mechanisms, or impede the movement of

the caster, mounts had to be made. With the remaining wood from the reinforcements,

the casters were fastened to the mounts with 1 ¼ inch wood screws.

Since the mounts on their own were not structurally sound, struts were made to

improve the strength of their attachment. Each strut was screwed into the mount and the

frame of the glider at a 45 degree angle to provide maximum force dispersion and

stability. For every screw that was used, the locations

of each connection had to be mapped and pre-drilled

to prevent splitting in the wood.

Figure 35. Completed Porch Glider Swing

Figure 36. Glider Bench Reinforcements

37

Padding

Since Nathan has a

weak torso, to prevent

injury, memory foam padding was implemented. There was a large amount of the

padding in the Machine Shop, and most of it was used for these pads. The memory foam

was cut to size for the bench padding, and there was enough left over for the back

cushion for Nathan.

Since it is very easy to make memory foam dirty, and it isn’t very aesthetically

appealing, Hunter used 300 thread-count sheets and sewed covers for the pads. The last

edge of each of the cases is secured with black Velcro to allow for removal of the covers

for cleaning.

Harness

To further prevent injury to our client, two safety belts were mounted to the bench

and back of the glider; one as a lap-belt and the other as a chest strap. The belts were

purchased from the NEAT Marketplace and were cleaner and more padded than any

other readily available option, and will keep Nathan safe while he rocks the glider.

Figure 37. Caster Attached to Mount and Strut

Figure 38. Padding for the Glider Bench and Back Pad

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3. Realistic Constraints

3.1 Constraints of

the Mobile Stander The main purpose of this project was to provide a mobile stander that Nathan can

use for years to come. The design chosen offers the most efficient route in order to please

the client. It is essential that we cover all-important constraints in order to effectively

ensure that we design the best mobile stander.

The client’s school will be providing us with the mobile stander we will be

augmenting, so the cost of creating one custom fit to Nathan’s needs will not be too

expensive. The design itself should be relatively cheap, so the economic constraints

would be kept to a minimum.

Given Nathan’s condition and the design of the stander, this product would not be

mass-produced. Essentially, most disabled people would use a wheelchair over a mobile

stander. The purpose of a stander is to offer a new perspective in movement. Most people

would only focus on movement and therefore only purchase a wheelchair. As of now,

there are no mechanically driven mobile standers on the market. Most have an electric

motor with a joystick control. Given our final product, we would be creating the first

lever arm driven mobile stander. And although it would be limited to very specific cases,

it would still be a first in the industry. The most difficult part of the project would be

effectively incorporating the one arm drive into the mobile stander in addition to the

braking system.

The main safety consideration would be the stability of the mobile stander.

Although there is always the possibility that the client can get hurt, we can minimize this

by having the mobile stander be as stable as possible. Considering Nathan will be using

this everyday, we have to ensure that the mobile stander can handle daily use.

3.2 Constraints of the Smart Kart As in many projects for people with disabilities, Nathan’s disability is the largest

constraint on this project. The purpose for this design was to fix the errors made by a

previous design team that either limited the operation of the device or made the device

less safe to operate. The design will correspond to our client’s desire for a working Go-

Kart while keeping Nathan safe. The new harness will ensure that Nathan is properly

secured, and the scissor lift will prevent his parents from injuring themselves while

Figure 39. Harness for Client’s use of Glider

39

placing him in the seat.

One economic constraint of this project is that higher quality parts are going to be

required, as some of the parts were of low quality from last year’s design and need to be

replaced. However, costs will not be as high as the original cost of building the Smart-

Kart from the ground up. Manufacturing concerns should not be an issue, as this project

has been custom-tailored to our client, and as such it will not have to be mass produced.

The sustainability of the design will be in providing oil and gasoline, and all

routine maintenance that all gas-powered devices require; oil changes, changing of spark

plugs, and occasionally replacing the battery when it runs out of charge. None of the new

changes to the design should require additional maintenance.

The kart will have to be able to function in slightly damp conditions, as well as

over dusty terrain. The materials used must not weaken over time from rust or loosening,

or the stability of the chassis and frame will be compromised. The kart already

compensates for other users and the growth of our client in that the headrest and armrests

are adjustable, but Nathan may still outgrow the device eventually, as he is currently only

twelve years old.

A social constraint to this project is the distance from our client, as well as the

clients’ schedules. As our clients are a working family, both of Nathan’s parents work

during the week, and Nathan’s sister has sporting and musical practices and

events. Meeting with our clients requires a drive to Stonington whenever they are free,

but other contact is maintained via email.

3.3 Constraints of the iPad App Since this project is being created to meet the needs of one client and will require

additional wireless devices to accomplish its end task, it would not be feasible for mass

production. However, since the design is largely electrical, small alterations could allow

it to be used by other clients, given that they properly program which playlist corresponds

with each of the three main interface buttons.

Economically speaking, the remote design would not be recommended for mass

production. However, the Airport could be used for other functions. The Airport also

works as a wireless modem and a repeater, which would further boost the range of the

clients wireless network. Since the client’s iPad is going to be the actual remote, and the

software for creating the app would not be an issue for large scale development, the only

large expense will be the PLCBus hardware.

3.4 Constraints of the Glider The biggest constraint for this project will be movement and location. Given that

the client lives a good distance away, it would be fairly difficult to build the glider at their

house and repeatedly travel to Stonington. To construct the device in a timely manner,

we will most likely be building the glider here and then transporting it when we have

finished.

Even though this design has us purchase and augment a pre-made glider, this

design will not be fairly expensive and should not be too much of a constraint on our

budget. The glider itself is mass produced, but they usually do not come with a restraint

system or casters. The fact that the glider is mass produced and that it will not be hard to

find casters or a harness system will not restrict us in any way.

40

41

4. Safety Issues

4.1 Safety Issues of the Mobile Stander When designing something like a mobile stander, it is important to take Nathan’s

physical condition into account. Nathan has very little support in his trunk and neck, so

this must be accounted for when designing the Mobile Stander. Nathan will be using the

mobile stander almost everyday in school. This means that Nathan would need to be

effectively secured with the harness system. As stated before, stability will also be an

important factor for safety. Considering he will be using this almost everyday for a few

years, the mobile stander must be stable enough to last. All components must be made to

sustain daily use.

4.2 Safety Issues of the SmartKart In the design of this project, safety will be our main concern. Correcting the

problems with steering and stopping will reduce this somewhat. Without the smart-

braking system, the kart has the potential to collide into objects, people, or structures. To

prevent that from happening, the kill switch should be utilized, or control of the kart can

be switched to the passenger with the steering wheel.

Replacing the existing 5-point harness with one that the clients will be able to

operate will properly restrain Nathan. This is a priority due to his weak torso which

causes him to favor his left side, and will additionally help to prevent his cerebral shunt

from being damaged. Correcting the turn radius will also make the device safer in

allowing the driver to avoid obstacles in its path.

4.3 Safety Issues of the iPad App Since this design is mostly programming, the remote will not have any safety

problems. The Airport may negatively impact the client’s sleep, as the device has a light

built in that is lit while it is plugged in. This could potentially cause illness due to sleep

deprivation, but will be prevented by placing it in an outlet behind furniture; in the

client’s house, there is one located behind the dresser upon which the iHome is located

4.4 Safety Issues of the Glider Safety is a major concern with this design. It is important to make sure Nathan

will be safe will sitting in the glider at all times. Although a glider would not have as

wide a range as a conventional swing, there is still a possibility that Nathan could get hurt

if proper precautions are not followed. The belt must be attached to the bench so that it

will not come loose at all as well as keep Nathan secure in his seat. In addition, the

movement of the glider when on casters can be an issue. Although a locking mechanism

will be used, the implementation of such a locking system must be handled with care so

that it does not fail and lead to any potential danger.

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5. Impact of Engineering Solutions

Although most of what is designed may not have a large demographic for mass

production, they all work on improving the way of life of one individual. Engineering

focuses on improving everyone’s way of life, and people with disabilities are usually

limited in their everyday freedoms as well as self-reliance. Engineering makes it possible

for people that have disabilities to become more self-sufficient as well as grant them

more freedom to do things as they please. These projects will offer Nathan a higher

degree of freedom as well as allow him to accomplish things with limited aid from

others. Designs such as the Smart Kart, mobile stander, and the iPod app further promote

the idea of self- reliance for those with disabilities. The Smart Kart allows Nathan to

enjoy the outdoors; the mobile stander with mechanical drive allows him to freely move

as he pleases indoors. These ideas not only offer a new perspective, but also help

integrate Nathan into social atmospheres. Many people with disabilities have their

hindrances get in the way of having a social life or enjoying things. As a child, it is easy

to distinguish differences between oneself and others. Offering ways to help these people

integrate into society will not only boost their confidence, but will also help minimize the

divide from what those who are handicapped can and cannot do. Effectively minimizing

the idea of having disabilities.

Mass marketing of the products in this project are not likely, most of these

products are specific only to those with disabilities, and some are specific to those with

limited cognitive abilities or physical control. Money to support some projects would

most likely be funded by public businesses interested in this demographic rather than an

agency. That being said, the idea behind making a more affordable, comfortable lifestyle

for disabled people has always been somewhat of an interest in society. As stated before,

as more of these products are being designed, the further we will continue to make

improvements.

6. Life-Long Learning

Having multiple designs for a single project can be daunting at first, but with the

proper preparation, can be accomplished. This project on the whole had taught us a

variety of lessons as well as improved upon many skills that will be essential in the

future.

There are many things that can go wrong with a single project, having multiple

projects increases this by much more. An essential skill to have is time management. Our

team quickly learned that with any sort of project, especially multiple ones, waiting till

the last minute causes complications. Working on these designs helped us more

effectively manage our time as well as coordinate to most efficiently work on and solve

problems. We learned how to more efficiently cooperate as a group in order to get a

greater amount of work done in a shorter amount of time. Cooperation and time

management is an important part of working in any field, so it is essential to work on

these with any opportunity.

Communication is essential with any sort of business. It is very important to keep

up communication not only with your client, but also with your fellow team members.

43

Keeping contact with the client will ensure that you get a good understanding of what

they want and what needs to be done. We effectively kept our modes of communication

varied; not having to rely on one sole method but leaning towards emailing mostly. It is a

good idea to speak with your client verbally and even better to physically meet them. By

meeting our clients at their house, we were able to gauge what would need to be done for

specific projects. For example, with the porch glider, we needed to see how big of a deck

they had and the width of the doors. Although the client told us the general measurements

over the phone, it wasn’t until we went to their home that we had gotten exact

measurements as well as a better feel of where we would be placing the glider. Further

communication with the client and client’s physical therapist over the phone and via

email has allowed us to further the projects as well. Communication between team

members is just as important; we were able to discern what needed to be done and

worked on getting specific tasks accomplished faster by effectively communicating to

each other. Without this, the projects would have taken much longer to be complete.

Lack of communication was also a factor identified with our projects, and

recognized as something that must be worked through in some cases, and worked around

in others. It was identified that when one team member fails to communicate or

collaborate with the other team members, the other members take on a greater share of

the burden to compensate, which is taxing emotionally and physically. The induced

stress, if not appropriately and maturely dealt with, can cast a negative feeling toward the

project, which will slow down progress and otherwise hamper the project’s completion

further than the increased workload on the other members would do alone.

Communication with the previous year’s design team and lack thereof in some aspects

was something we should have worked around. For example, if we had identified that we

were not likely to get assistance from graduates for the PCB layout sooner, we would

have acquired our Arduino board sooner, which would have spend things along. Instead,

we were waiting for a train that had long left the station and had no interest in turning

back. That, among other things, would have been valuable in the interest of completing

our projects sooner.

There are many skills involved in the actual implementation and creation of a

design, the first being designing a product. This itself is a very important skill; being

innovative and practical is what keeps a company ahead. This sort of skill can often be

associated with problem solving. The client offers you a problem, and you have to find

the most efficient way of doing so. We were able to think of and design products that

pleased our client as well as kept the budget to a minimum. At this point we haven’t

worked too much on the designs themselves, but we have gotten the opportunity to work

on 3D modeling programs such as SolidWorks as well as Microsoft Visio. It is a good

idea to have a model of what you’re going to make before you make it. This essentially

decreases the chance of you actually messing up during the manufacturing phase.

Modeling programs are used all the time in industry, so becoming better acquainted with

such programs is a must. In the future, we will get to work more on our mechanical and

programming skills by actually implementing our designs. The combination of all these

skills leads to the successful creating of a product.

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7. Budget

7.1 Budget The $2000 budget we assumed we had and would use was an over-estimate. Due

to shopping around and using all of the materials at hand, we ended up under

SmartKart

Part Cost Shipping

5-point harness 69.95 17.50

Rod Stock 25.71 4.50

Sheet Steel 43.06 60.56

Joystick (uniaxial) 114.00 0.00

Joystick (biaxial) 174.00 0.00

Miscellaneous 0.00 0.00

Subtotal 426.72 82.56

Total 509.28

iHome Remote

Part Cost Shipping

Apple Airport 88.56 4.95

Miscellaneous 25.00 0

Subtotal 175.67 12.99

Total 188.66

Porch Swing

Part Cost Shipping

Porch Glider 116.33 0.00

Harness 10.00 0.00

Subtotal 126.33 0.00

Total 126.33

Mobile Stander

Part Cost Shipping

Apple Airport 50.00 0.00

Miscellaneous 33.92 0.00

Subtotal 83.92 0.00

Total 83.92

Overall Expenditure = $ 908.91

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8. Team Member Contributions

8.1 Hunter D’Addeo For the SmartKart circuitry, Hunter disassembled and mapped all of the

components, making note of what needs to be repaired and replaced. Once the Arduino

board was in our possession, he reassembled the speed controller circuit and connected

the battery for testing. He fashioned the joystick housings from electrical component

boxes, and once testing was complete, repackaged the circuitry. He also fabricated the

housing for the speed controllers and Arduino board. To correct the turning radius,

Hunter disassembled the front end of the kart and reconfigured the wheels with the rack

and pinion for optimal turning range in either direction. He also collaborated with Saif to

get the potentiometer values for the steering potentiometer, as well as the actuators for

braking and throttle. Hunter also uninstalled many of the mechanical components in the

kart, installing them once the circuitry was completed, making modifications where

necessary.

For the iHome Remote, Hunter created the programming under the visual

interface that controls the music output based on user commands. He registered as a

developer with Apple, and started by deconstructing various apps to figure out how to

best compile them into a single code to command the music. Afterward, basing his initial

design on the free source code for “AddMusic,” he started building the Objective C

coding that does all of the work behind the scenes. Next, Hunter designed and

programmed the user-interface code in the Interface Builder, making the layout as simple

yet effective as possible. While working on debugging the code and removing errors, he

created all of the bureaucratic files and images necessary for submission to Apple. When

he encountered the host of errors due to key and class coding errors, he researched

potential solutions and eventually found that it was necessary to change how the app was

initiated. Upon completing the app, he submitted his code to Apple for revision and

approval.

For the mobile stander, Hunter went to NEAT Marketplace to purchase the

one- arm drive, and rebuilt it to function for the left side of the stander, as it was meant

for the right side of a wheelchair. He collaborated with Saif in removing all of the

accessories from the frame and adding the adjustments to the main shaft and drive arm.

He then tooled the bracket to hold the bushing for the steering caster and attached the

parts of the one-arm drive to the frame of the stander. In rebuilding the stander, he found

all of the necessary fittings for the attachment of padding to the new frame. He attached

the new pads, and then he tested the stander with Saif, and they worked together to solve

any remaining problems.

For the porch swing, Hunter reinforced the bench, constructed the caster

mounts and struts, and attached them to the glider along with the safety belts. Once the

mechanical solutions were completed, he cut down memory foam to fit the bench and to

form a back pad for Nathan. He then sewed the cover for the cushions.

Hunter arranged meetings and met with Saif multiple times weekly in either the

Senior Design Lab or other locations to further their projects, with occasional help from

others.

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8.2 Saif Ejaz For the SmartKart, Saif started off learning how to reprogram the PIC16s from

the previous year’s design team. He collaborated with Hunter in removing the

mechanical and electrical components from the kart, including the shifting mechanism.

He had figured out how to change the previous design team’s code to make it more

effective and efficient, but then we were not able to get a copy of the modified PCB file

and switched to an Arduino board. Once he got the board, he converted all of the

existing code into the much more programmer-friendly Arduino language, making

revisions and improving on their design. The original code used segments such as “if-

else statements” and “for loops” or “while loops” that only checked sets of conditions

and then had the same output for large ranges of potentiometer and monitor values. Saif

was able to map the inputs from the potentiometers and actuators, and create an

attenuated system that had variable outputs based on variable inputs. Saif then tested all

of the electrical components with the Arduino board, with some assistance from Hunter.

He then worked to debug the code, tuning the output frequency of the board to match

the acceptable input frequency range of the speed controllers. and once the circuitry was

complete, he assisted Hunter with the reconstruction and packaging of the kart.

For the mobile stander, Saif arranged for the Tiger Team to pick up the original

model from Nathan’s school. He then machined all of the parts that let the one arm

drive mechanism fit onto the stander’s wheel. The wheel had to be aligned properly with

the drive gear, which required machining a large aluminum bushing to fit between the

wheel and the drive gear. The wheel and bushing then had to be fitted with pins that

acted as spokes to ensure that the wheel would turn properly when the one-arm drive

lever was pushed. To ensure the proper distance between the mechanism and the frame

of the stander, a large plastic bushing had to be created and milled repeatedly until it

was the correct size. Once all of the drive components were in place, he retooled a bolt,

making it the correct length to fit through the wheel, drive mechanism and frame,

threading the end to allow it to be secured in place. He then worked with Hunter to test

the stander and solve the remaining problems that occurred.

Once the glider swing arrived, Saif constructed it from the ground up, testing

all of the flex joints and making sure the bolts did not cause any of the wood to crack.

For general design team based work, Saif filed all of the purchase requisitions

and kept track of the budget. He kept in constant communication with Janice Lamb and

Dr. Deborah Widmer-Reyes, and kept both the design team and the client informed on

developments in the projects or the client’s desires. Saif and Hunter stayed in constant

contact for the duration of the second semester as well, and were able to accomplish

their goals.

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8.3 Diana Manivong For the SmartKart, Diana talked to Robert Amatuli, one of the members from

last year’s senior design team. From Robert, she received Cameron’s contact information

and the original SolidWorks design. Cameron is another member from last year’s team

and provided us with all of his programming codes he did for the SmartKart.

Diana did some review of the parts and assembly in order to note which parts

need to be replaced or removed. She has been learning how to use SolidWorks and

started making SolidWorks drawings of some of the parts that we will be adding or

replacing on the original design. Also, she has been familiarizing herself with C/C++

code as to be able to understand and reprogram the current microcontrollers in the

SmartKart. In the future, Diana will be working on the microcontroller for the brakes on

the SmartKart

Diana is enrolled in the machine shop safety class for the winter session. Once

machine shop certified, she will be able to help Hunter with any of the machining

components we need to get done for all the projects. As for the iPad App, Diana is

researching the programming codes on current iPad Apps that are similar to what we are

trying to design in order to have a basis for our own application.

9. Conclusion

The projects for Nathan Lamb will allow Nathan to satisfy his craving for

movement or motion; giving him the stimulation he needs to progress and giving him the

adrenaline rush that he loves. The projects also give him the potential to increase his

independence and decision-making as well as give him mobility from a different

perspective.

Fixing the SmartKart and making it safer and more effective will allow Nathan

to experience the outdoors in an exciting way. It will also give him bonding time with his

father, or any other passengers, while giving him some sense of independence to control

where he moves. The SmartKart is unique in that it is customized for Nathan and there

are no other commercial go-karts like it. The passenger will have control of the kart as

well via a conventional steering wheel and throttle joystick instead of the formerly

installed Xbox controller. This will enhance the safety of the vehicle since the current

passenger control is unpredictable and therefore unsafe. The former harness system was

difficult for the client to use so it was replaced with the simpler 5-point harness system

similar to seatbelts that they are already know how to use. The turning ability of the front

wheels was increased, which in turn makes it so the turn radius of the kart was drastically

improved. The new Arduino board and the new code design also allow for a higher

degree of control in the kart, which is necessary due to the fact that the smart braking

system had to be removed due to incompatibility of the

The iHome controller will give Nathan some independence and allow him to

have some control over and make his own decisions. There are currently no iHome

controllers in the market that are simple enough for people with cognitive challenges to

use. The simplicity of this device is what makes this device different. The Z-wave

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programming to be used has been used already in iPad apps, as has the Airplay feature

with iTunes and other stereos. However, since we will be using an iPad in addition with

the iHome and the wireless light switch in a single app, we will be breaking ground on

multi-interfacing with a single application.

The gliding porch swing will let Nathan experience the sensation of movement

while remaining relatively stationary. This device will be unique in its increased

stability, as well the ease with which it can be transported. Since there will be seating for

two people, Nathan will be able to spend more time with his peers, which was a request

of our clients.

In designing an adjustable one arm drive mobile stander that is able to fit

Nathan and accommodate his growth, we will be giving Nathan motility in a different

perspective than his wheelchair gives him. Nathan is accustomed to being in the seated

position. This mobile stander gives him the opportunity to be standing and at the height

level of his peers. In effect, it will make him feel less secluded from everyone and have a

positive impact on his social interactions. Nathan’s physical therapist had difficulty in

finding a one-arm drive mobile stander that will fit Nathan. This device is unique because

it is hard to find an adjustable mobile stander that is supportive and big enough for

Nathan as well as having the ability to be controlled with one arm.

The main goals of these projects are to improve the style of living of those with

physical and mental disabilities. They offer new perspectives in mobility and offer a

greater amount of decision-making and free choice for the user. By implementing the

previous designs, this idea can become a reality for the client and offer a new perspective

on improving the lives of those with disabilities in the future.

10. References

[1] Apple iOS Dev Center <https://developer.apple.com/devcenter/ios/index.action>

Nov 9, 2011.

[2] Senior Design Team 9 <https://www.bme.uconn.edu/sendes/Spring11/Team9/>

Sept 10, 2011.

[3] “Lever Drive Wheelchairs Mechanical Details.” Feb. 2008. [cited Oct. 10 2011.]

< http://www.forethoughtdesigns.com/My_Homepage_Files/Page40.html>

[4] “Magic Walker, L.C.” March 31, 1998. [cited Sept 19 2011.]

<http://www.patentstorm.us/patents/5732964/description.html>

[5] “Throttle and Brake Assemblies.”Limestone media.

2009.<http://www.limestonemedia.com/how-to-plans/go-kart-parts.htm

49

11. Acknowledgements

Lamb Family: Janice, Harvey, Nathan, and Hannah

Dr. Debra Widmer-Reyes

Dr. John Enderle

Marek Wartenberg

Robert Amatuli

Cameron Fulton

Patrick Boyd

Ian Rogers

Constantine Poulos

Fred Wright

Antonio D’Addeo

Jordan Smith

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12. Appendix

12.1 Updated Specifications

12.1.1 Mobile Stander Operational Specifications:

Physical:

Type of Material Aluminum Frame

Non-latex based supports, straps, and cushioning

Mechanical

Size <34” x 34”

Weight <35 lbs

Weight Capacity 100 lbs

Environmental

Storage Temperature 40-80 degrees F

Operating Temperature 40-125 degrees F

Operating Environment Outdoors, Indoors, flat terrain

Safety

Harness with leg and torso straps

Hip supports

Protruding wheels to prevent capsize

Maintenance

Cleaning

Lubrication

Size adjustments as needed

12.1.2 SmartKart Operational Specifications:

Physical:

Type of Material: Steel frame, with Aluminum

Mechanical

Size: 81 x 44 x 25 inches (l x w x h)

Maximum Load 300 lbs

Maximum Speed 20 mph

Electrical

Voltage Range up to 12V DC

Current Range up to 9 Ah

Environmental

Storage Temperature -10 to 125 degrees F

Operating Temperate 0 to 100 degrees F

Operating Environment outdoors, clients yard

Safety

Five-point harness

Seat belt for passenger

Leg supports for driver

Roll cage

Trunk and head support for driver

51

Arm rests

Kill-switch

Case for circuits

Barrier between steering motor and passengers

Maintenance

Battery recharge

Tire Pressure

Cleaning

Lubrication

Adjustments for growth of client

12.1.3 iHome Remote Operational specifications:

Physical:

iPad

Apple Airport Express

Mechanical:

Size (iPad): 9.56×7.47×.528 in

Weight (iPad): 1.5 lb

Electrical:

Wireless Range 50 yards

Requires AC Outlet to perform wireless music interfacing

Environmental:

Storage Temperature: 40 to 125 degrees F

Operating Temperature: 40 to 125 degrees F

Operating Environment: Indoors, Nathan’s room

12.1.4 Porch Swing Operational Specifications:

Physical:

Type of material: Wooden frame, Memory foam padding.

Mechanical:

Size: 3 ft. tall by 4 ft. 4 in. across and 2 ft. 2 in. wide

Weight: <60 lbs. fully assembled

Swing range: <±30º from Center/Rest

Maximum load: 300 lbs.

Safety:

Lockable casters to

Safety belts to prevent Nathan from falling out

Padding for comfort and support

Environmental:

Storage Temperature: -40 to 120 degrees F

Operating Temperature: -40 to 120 degrees F

Operating Environment: Outdoors, Client’s deck