Project Proposal and Feasibility Study
Team 11
Heather Kloet
Kaitlyn Weinstein
Monica Wood
Engineering 339 Senior Design Project
Calvin College
08 December 2014
©2014 Heather Kloet, Kaitlyn Weinstein, Monica Wood, and Calvin College
Executive Summary
Finding lost objects in marshes or shallow black-water can be a frustrating, unpleasant, and time consuming
task for humans. An amphibious robot would alleviate the stress of locating metallic objects by using a
combination of metal detection, GPS, and sonar to give a more defined location of the object. Using a
wirelessly controlled robot allows a person to look for objects from the comfort of a boat or on shore. In
this paper, the feasibility of designing and prototyping an amphibious robot for this purpose is determined.
The robot will consist of a central body, tracks for locomotion, and electronics for communication. The
body will consist of two motors for driving the tracks in forward and reverse directions, a front mounted
camera to aid in steering, and a dry box that will house a Raspberry Pi, router, battery, and sensors. The
sensors will include a GPS, a temperature and humidity sensor, sonar, and a metal detector. The treads will
be driven by a pressure wheel and have long rubber treads that will provide traction on land and act as
paddles in water. The estimated cost to prototype the robot is $500. The robot will weigh no more than 50
pounds and the structure will be a maximum of 3 feet in diameter. This will allow the robot to be easily
transported. The robot will be able to travel and communicate a quarter mile on land. The robot will be
communicated with from a separate location using Wi-Fi through a router. Video feed from the robot and
GPS coordinates will allow the user to determine the location of the robot and maneuver it using controls
on a laptop or phone application.
Table of Contents
1
2
Introduction ........................................................................................................................................... 1
1.1
Calvin College and the Engineering Department.......................................................................... 1
1.2
Calvin College Senior Design Project .......................................................................................... 1
1.3
Project Specification ..................................................................................................................... 1
1.4
Team Member Bios....................................................................................................................... 1
1.4.1
Heather Kloet ........................................................................................................................ 2
1.4.2
Kaitlyn Weinstein ................................................................................................................. 2
1.4.3
Monica Wood....................................................................................................................... 2
Project Management ............................................................................................................................. 3
2.1
2.1.1
Heather Kloet ........................................................................................................................ 3
2.1.2
Kaitlyn Weinstein ................................................................................................................. 3
2.1.3
Monica Wood........................................................................................................................ 3
2.1.4
Other Management Tasks ..................................................................................................... 3
2.2
Methodology ................................................................................................................................. 3
2.2.1
Schedule ................................................................................................................................ 4
2.2.2
Budget ................................................................................................................................... 4
2.3
3
Team Member Responsibilities .................................................................................................... 3
Project Milestones ......................................................................................................................... 5
2.3.1
Fall Semester Completed Milestones .................................................................................... 5
2.3.2
Spring Semester Planned Milestones .................................................................................... 7
Project Clarification ............................................................................................................................ 11
3.1
Problem Specification ................................................................................................................. 11
3.2
Customer ..................................................................................................................................... 11
3.3
Requirements .............................................................................................................................. 11
3.3.1
Performance Requirements ................................................................................................. 11
3.3.2
Physical Requirements ........................................................................................................ 12
3.3.3
Electronic Requirements ..................................................................................................... 12
3.3.4
Interface Requirements ....................................................................................................... 14
3.3.5
Cost Requirements .............................................................................................................. 14
3.4
Deliverables ................................................................................................................................ 14
3.4.1
Fall Semester Deliverables.................................................................................................. 14
3.4.2
Spring Semester Deliverables ............................................................................................. 15
ii
4
Design ................................................................................................................................................. 16
4.1
4.1.1
Critical Considerations ........................................................................................................ 16
4.1.2
Design Norms ..................................................................................................................... 17
4.2
Propulsion System ...................................................................................................................... 17
4.2.1
Alternatives and Research ................................................................................................... 17
4.2.2
Decision .............................................................................................................................. 22
4.3
Materials ..................................................................................................................................... 23
4.3.1
Alternatives and Research ................................................................................................... 23
4.3.2
Decision .............................................................................................................................. 24
4.4
Body ............................................................................................................................................ 24
4.4.1
Structure .............................................................................................................................. 24
4.4.2
Casing ................................................................................................................................. 25
4.4.3
Dry Box ............................................................................................................................... 25
4.4.4
Layout ................................................................................................................................. 26
4.4.5
Size ...................................................................................................................................... 27
4.5
Onboard Computer...................................................................................................................... 27
4.5.1
Alternatives and Research ................................................................................................... 27
4.5.2
Decision .............................................................................................................................. 28
4.6
Remote Communication ............................................................................................................. 28
4.6.1
Alternatives and Research ................................................................................................... 28
4.6.2
Decision .............................................................................................................................. 29
4.7
Sensors ........................................................................................................................................ 30
4.7.1
Global Positioning System (GPS) ....................................................................................... 30
4.7.2
Onboard Camera ................................................................................................................. 31
4.7.3
Humidity and Temperature Sensor ..................................................................................... 33
4.7.4
Sonar ................................................................................................................................... 34
4.7.5
Metal Detection ................................................................................................................... 35
4.8
5
Design Criteria ............................................................................................................................ 16
User Interface .............................................................................................................................. 37
4.8.1
Graphical User Interface (GUI) .......................................................................................... 37
4.8.2
Mobile Application ............................................................................................................. 38
4.8.3
Motor Control ..................................................................................................................... 38
Business Plan ...................................................................................................................................... 40
iii
5.1
5.1.1
Competition......................................................................................................................... 40
5.1.2
Differentiation ..................................................................................................................... 40
5.1.3
Distribution ......................................................................................................................... 40
5.2
6
Marketing .................................................................................................................................... 40
Final Product Cost Estimate........................................................................................................ 40
Feasibility............................................................................................................................................ 43
6.1
Risks............................................................................................................................................ 43
6.1.1
Movement ........................................................................................................................... 43
6.1.2
Wireless Communication .................................................................................................... 43
6.1.3
Floatation ............................................................................................................................ 43
6.1.4
Metal Detector..................................................................................................................... 43
6.2
Time Constraints ......................................................................................................................... 44
7
Conclusion .......................................................................................................................................... 45
8
Acknowledgements ............................................................................................................................. 46
References ................................................................................................................................................... 47
iv
Table of Figures
Figure 1: Team 11 Monica Wood, Kaitlyn Weinstein, Heather Kloet ......................................................... 1
Figure 2: Electronic Block Diagram ........................................................................................................... 13
Figure 3: Screw Propulsion ......................................................................................................................... 18
Figure 4: Foldable Paddles.......................................................................................................................... 18
Figure 5: Foam Treads ................................................................................................................................ 19
Figure 6: Paddled Wheels ........................................................................................................................... 19
Figure 7: Propeller ...................................................................................................................................... 20
Figure 8: NASA Crawler ............................................................................................................................ 21
Figure 9: Duck Boat .................................................................................................................................... 21
Figure 10: Tracks ........................................................................................................................................ 22
Figure 11: Amphibot Treads ....................................................................................................................... 22
Figure 12: Liquid Foam .............................................................................................................................. 23
Figure 13: Used Tires.................................................................................................................................. 24
Figure 14: Preliminary Frame Design ......................................................................................................... 25
Figure 15: Dry Box ..................................................................................................................................... 26
Figure 16: Amphibot Preliminary Layout ................................................................................................... 26
Figure 17: The Raspberry Pi B+ ................................................................................................................. 27
Figure 18: The BeagleBone Black .............................................................................................................. 28
Figure 19: Wifi............................................................................................................................................ 29
Figure 20: Bluetooth ................................................................................................................................... 29
Figure 21: Zigbee ........................................................................................................................................ 29
Figure 22: Adafruit Ultimate GPS .............................................................................................................. 31
Figure 23: Creative Webcam ...................................................................................................................... 32
Figure 24: GoPro Hero................................................................................................................................ 33
Figure 25: DHT22 Sensor ........................................................................................................................... 34
Figure 26: Side Scan Sonar ......................................................................................................................... 35
Figure 27: Surf PI 1.2 Metal Detector......................................................................................................... 36
Figure 28: Tiny PI Metal Detector .............................................................................................................. 37
Figure 29: Visual Studio ............................................................................................................................. 37
Figure 30: Application Platforms ................................................................................................................ 38
Figure 31: Joystick ...................................................................................................................................... 39
Table of Tables
Table 1: Individual Hours Breakdown .......................................................................................................... 4
Table 2: Cost of Parts.................................................................................................................................... 5
Table 3: Spring Semester Milestones............................................................................................................ 7
Table 4: Parts' Cost Estimate ...................................................................................................................... 41
Table 5: Break Even Analysis..................................................................................................................... 42
v
1
Introduction
Team Amphibot consists of Heather Kloet, Kaitlyn Weinstein, and Monica Wood. The team is working to
create an amphibious robot which will be capable of driving on land and propelling through water in
order to find small metallic objects in marshes, swamps, and shallow black-water. This project meets
requirements for Calvin College Department of Engineering’s Senior Design Project.
1.1
Calvin College and the Engineering Department
Calvin College is a well-renowned college with academic excellence. It is a liberal arts college based in
the Christian Reformed faith. The engineering program is one of Calvin’s top programs for its
combination of liberal arts and technical aspects. Its courses enable students to learn both hands-on and
theoretical methods. Calvin works to prepare students for real-world situations and be equipped to handle
them using a Christian perspective.
1.2
Calvin College Senior Design Project
The Senior Design Project is the two-semester capstone of Calvin’s Engineering program. The goal of the
senior design project is to test and develop engineering students’ understanding of the process of
engineering design, the ability to work in a team, and basic engineering skills learned over the past three
years.
1.3
Project Specification
This senior design project will be an amphibious, remote-controlled vehicle. The vehicle, named
Amphibot, will be equipped with a number of sensory devices, including GPS, sonar, a metal detector,
and webcam, for the purpose of finding small objects lost in black water, mud, and marshes. Amphibot is
designed to be useful for fishermen, boating enthusiasts, and other water hobbyists who might need to
find items lost in shallow water. It also has use for local sheriffs’ departments aiding in car wrecks and in
criminology by finding weapons such as guns or knives.
1.4
Team Member Bios
The team consists of Heather Kloet, Kaitlyn Weinstein, and Monica Wood, pictured below in Figure 1.
Figure 1: Team 11 Monica Wood, Kaitlyn Weinstein, Heather Kloet
1
1.4.1
Heather Kloet
Heather is an electrical and computer engineering student. She was born and raised in
Grand Rapids, MI. In her spare time, she volunteers at Frederik Meijer Gardens Gift
Shop. She hopes to continue her education with a Master’s Degree in computer-based
fields. She enjoys reading, shopping, and listening to music. She is excited to work on
the electrical and software components of the project and help further develop
underwater exploration.
1.4.2
Kaitlyn Weinstein
Kaitlyn is a mechanical engineering student. She grew up on a farm in Leslie,
Michigan, which sparked her interest in mechanical engineering. She is pursuing a
full-time mechanical engineering position in the mid-Michigan area in order to be
near her family. In her spare time she enjoys reading, drawing, and making stuff. She
also has a minor in architecture, which she is hoping to use to build her dream home.
She is excited to work with the structure and propulsion of the robot on land and in
water.
1.4.3
Monica Wood
Monica is an electrical and computer engineering student. As the daughter of an Air
Force officer, she moved a lot throughout her childhood, attending three different
high schools and living in 7 different states. She is a cadet in the Army ROTC
program of Western Michigan University, and will be commissioning as an Active
Duty Signal Corps officer in May 2015. In February 2015 she will marry her best
friend, Cody Limback, and they hope to live in Germany for many years both during
and after her Army service. She enjoys reading, writing, and playing video games
with her fiancé. She is excited to use her knowledge of electrical engineering to build
a robot that has both civilian and military possible applications.
2
2
Project Management
2.1
Team Member Responsibilities
The team is made of a total of three members. Each team member has a set of responsibilities for which
she is ultimately responsible.
2.1.1
Heather Kloet
Heather is primarily responsible for the software components of Amphibot. She will oversee
communicating with Amphibot wirelessly, writing software for the user interface, and determining how
Amphibot will be controlled and steered by the user. She will also work with Kaitlyn to connect the
motors to the electronic systems to power Amphibot.
2.1.2
Kaitlyn Weinstein
Kaitlyn is primarily responsible for all aspects of Amphibot’s mechanical body and movement. She will
oversee the design of Amphibot’s body, choose and implement necessary motors, and design and build
the propulsion system. She will determine material needs and costs, as well as size, weight and other
physical limitations.
2.1.3
Monica Wood
Monica’s primary responsibility is for the hardware and sensors Amphibot will use to find objects and
track its location. She will oversee the purchase and implementation of the sensors, and will work with
Heather to integrate each sensor with the end user by use of a single board computer.
2.1.4
Other Management Tasks
As part of the team’s success, other management tasks were assigned to team members to ensure smooth
operation and allow the team to meet deadlines.
2.1.4.1
Team Webmaster
Heather will serve as the team Webmaster. The senior design team was tasked with developing a team
webpage that details the progress of the project, shares documentation, and serves to promote Calvin
College and the Senior Design project. Heather agreed to take on the task because of her familiarity with
Dreamweaver software and prior work in creating websites.
2.1.4.2
Weekly Project Leader
The team assigns a project leader, who is responsible for ensuring weekly goals are met, providing
weekly summaries to the team’s faculty advisor, and overseeing the work schedule for the week. To better
balance that responsibility, the leadership position is rotated on a weekly basis between all members of
the team.
2.2
Methodology
In order to maintain good relationships, effectively utilize time, and produce a quality product, the team
has developed a method of weekly, all-team meetings combined with individual time and work. Time
spent on the project is tracked by an Excel sheet. Communication and document sharing is accomplished
via a combination of verbal conversations, email, Google Drive folders, Microsoft OneDrive, and the
Calvin College network shared drive.
3
2.2.1
Schedule
The team has scheduled biweekly meetings on Monday and Wednesday for an hour at 12:30 P.M. each
day. This time is spent on updating one another on individual progress, as well as to set short-term goals
and discuss overall progress. In addition to this group time, each team member is responsible for spending
at least a half hour per work day on the project, and for logging this time and what they did in a
scheduling table.
2.2.1.1
Fall Semester Work Breakdown Schedule
During the fall semester, the schedule was broken down between time spent as a team and time spent
individually. Each team member was asked to spend at least 30 minutes a work day putting effort into the
project in order to see it through to completion. As of now, individual time nets at a total of 139 total
hours of individual work, broken down in Table 1.
Table 1: Individual Hours Breakdown
Name Number of Hours Worked
Heather
48
Monica
44
Kaitlyn
47
Total:
139
The team spent two hours per week in regularly scheduled team meeting times, as well as spending extra
time at key points along the project, particularly when deliverables were due. This time nets to 24
regularly scheduled hours over the course of the twelve weeks of the semester. Additional time spent
working together summed to a total of 50 hours, which together makes a total of 74 hours of combined
effort. With the three team members working during this time, the individual work hours amount to 225
hours. Overall, the project has taken 364 hours of labor this semester.
2.2.1.2
Spring Semester Work Breakdown Schedule
As the spring semester is about building a prototype as well as doing additional research and narrowing of
scope, it is predicted that the project will take at least 3 times the amount of man-hours in the spring as in
the fall. Thus, the team plans to spend no less than 675 hours, or 225 per person, on the project. As the
spring semester and interim allows for 14 weeks before the Senior Design Night, this means a work load
of 17 hours per week per person. This is the equivalent of a part-time job, and should be manageable
during the semester.
2.2.2
Budget
In order to take charge of the budget, each desired component, sensor, tool, or piece of material for
Amphibot is researched for the best deal. Once a specific item has been chosen, the team member who
requests it will enter the item into a spreadsheet with the item’s cost. As a team, these components are
discussed and approved depending on their cost and level of necessity. Because many of the parts needed
for Amphibot can be quite expensive, the team is working hard to find the components that are cheapest
for what is required in order to stay within the set budget. The final purchasing cost list is shown below in
Table 2.
4
Table 2: Cost of Parts
Budget
Available Budget
$500
Items
Quantity Unit Cost Expected Cost Actual Cost Purchased?
Temp/Hum Sensor
1
10
10
9.95 Yes
Raspberry Pi
1
40
40
37.44 Yes
GPS Breakout
1
40
40
39.95 Yes
USB to TTL Serial Cable
1
10
10
9.95 Yes
Webcam
1
40
40
17.99 Yes
Breadboard
1
5
5
0 No
Wifi Dongle
1
7.5
7.5
0 No
Electric motor
2
25
50
0 No
Wheel
8
7
56
0 No
Sonar
1
25
25
0 No
Metal Detector
1
45
45
0 No
Nuts and Bolts
20
0.2
4
0 No
Male to Male Wires
1
2
2
0 No
MicroSD Card
1
12
12
0 No
Total Spent
Total Left
2.3
$346.50
$154
$127.68
$372
Project Milestones
The team used a list of specific tasks throughout the semester as milestones to judge completed progress
and future goals. The milestones completed in the fall semester are laid out in this section, as well as
predicted milestones for the spring.
2.3.1
Fall Semester Completed Milestones
With the close of the fall semester, the fall milestones discussed below are key tasks the team
accomplished during the semester.
2.3.1.1
Form the Team
The first step in the senior design project was finalizing the teams. Monica, Heather, and Kaitlyn
developed their team based on similar work ethics and personalities, as well as mutual desires for an
interesting, multi-discipline project.
2.3.1.2
Select the Project and Receive Approval
Team 11 chose a project based on group interest and perceived feasibility. The team was fascinated by
robotics and the implementation of electronics into a mechanical system. An amphibious robot was
chosen for its unique challenge and level of interest.
2.3.1.3
Create a Work Breakdown Schedule
The team created a schedule of work based on deliverable due dates, expected difficulty of each task, and
additional considerations such as school breaks and test schedules.
5
2.3.1.4
Meet with Industrial Consultant
Team 11 was assigned an industrial consultant who would act as a guide and mentor in helping determine
key tasks, points of research, and feasibility. During the meeting with industrial consultant, Eric Walstra
of Gentex Corporation, the team was able to form a more narrowed scope with a specific set of
requirements, as well as develop a timeline and research needs.
2.3.1.5
Provide Weekly Status Reports to Faculty Consultant
Mark Michmerhuizen of the Electrical and Computer concentration served as faculty consultant and
guided the team through the senior design project as a class. In order to better help judge team progress
and provide advice and recommendations, Professor Michmerhuizen requested weekly status reports
summarizing completed tasks, goals for the following week, and any struggles perceived.
2.3.1.6
Meet with Mentor
Professor Renard Tubergen of the Mechanical concentration at Calvin College was recommended to
Team 11 due to his knowledge of underwater operations as a hobbyist diver. In meeting with Professor
Tubergen, the team was able to narrow the scope of its project even further, allowing for a project with a
feasible scope for senior design.
2.3.1.7
Continuous Research
Research for Team 11 is an unending task. However, the predominant research was completed during the
fall semester to determine specific design decisions and feasibility of aspects of the project.
2.3.1.8
Complete Presentations and Posters for Senior Design
Because the senior design project is a capstone class at Calvin College, certain requirements like team
presentations and team posters had to be fulfilled. The team incorporated these deadlines into its work
breakdown schedule, and made sure to complete them in time.
2.3.1.9
Create and Continue to Update Team Website
Each senior design team is responsible for creating and maintaining a team website. Heather, as team
webmaster, spent time in the fall creating a website that introduced the team and the project. This website
will be maintained throughout the project.
2.3.1.10 Complete the Project Proposal and Feasibility Study
The PPFS was the major milestone of the fall semester. A draft of the PPFS was submitted for approval
from the faculty advisor in November. The final PPFS marks the end of the fall semester, and is due at the
end of classes in December.
2.3.1.11 Acquire Parts and Begin Testing
With the time remaining in the fall semester, the team began the process of acquiring parts and
performing preliminary testing on those parts. The team purchased its Raspberry Pi, GPS, webcam, and
humidity and temperature sensor, and acquired tread from the campus fitness center's treadmill. Heather
and Monica were able to program the Raspberry Pi to run the webcam, and then to view the webcam feed
on another computer via the wireless network. They also began the process of implementing the GPS with
the Raspberry Pi.
6
2.3.2
Spring Semester Planned Milestones
The spring semester of senior design is when the research and project planning must culminate in a
working prototype of the project. The team has determined planned milestones for the spring that will
allow for on-time completion of the Amphibot prototype. Table 3 below shows the milestones with
desired deadlines. The milestones are detailed in the following sections.
Table 3: Spring Semester Milestones
Completion Date
December 31, 2014
January 20, 2015
January 31, 2015
February 28, 2015
March 15, 2015
March 31, 2015
April 15, 2015
April 30, 2015
May 5, 2015
May, 9 2015
To Be Determined
Milestone
Test Motors
Set up Router and Wi-Fi
Create Tracks
Test GPS
Obtain Metal Detector
Create Frame and Mount Treads
Test Humidity Sensor and Sonar
Create GUI Framework
Develop Movement and Motor Controls
Finalize Buoyancy
Finalize and Test Metal Detector
Combine and Test Sensors
Interface with GUI
Mount Electronics into Robot Body
Create Android App
Build Cover and Complete Robot Assembly
Test Robot and Make Final Alterations
Prepare Senior Design Night Presentation
Complete All Senior Design Deliverables
2.3.2.1
Test Motors
Two motors will be driving the robot and it is essential that they perform to the requirements. The motors
will be tested in order to make sure they work in forward and reverse. A load will then be applied and the
maximum speed they are capable of and amount of torque they can provide will be measured. They also
will be run for a long period of time in order to measure battery life.
2.3.2.2
Set up Router and Wi-Fi
The router and Wi-Fi will be the means of communication between the user and Amphibot. A secure
WLAN network will be set up to allow for communication to be possible. The router will be on-board
Amphibot and exchange data to the laptop and Raspberry Pi via Wi-Fi.
2.3.2.3
Create Tracks
The tracks are what propel the robot on land and in the water. They must go through an iterative process
in order to determine the optimal sizes and positions of the treads. The materials must be obtained and the
tracks constructed which will be a lengthy process given the number of materials needed and the
manufacturing required. They will be attached to a motor separate from the body to test functionality.
7
2.3.2.4
Test GPS
The GPS will be the tool for letting the user know where Amphibot is and where the object detected are
for future retrieval. The GPS will be able to easily interface with the Raspberry Pi which will convert the
data to GPS coordinates for the GUI. Testing will be done to ensure accuracy of the GPS locations.
2.3.2.5
Obtain Metal Detector
The metal detector is one of the more critical aspects of the senior design project, as without it, the robot
is unable to accomplish its task. Additionally, the robot frame size is dependent on the size of the
electronic components, and the metal detector is likely to be the largest of these. Thus, it is important that
the physical metal detector is chosen and obtained early in the semester to allow for the body to be
designed around its size.
2.3.2.6
Create Frame and Mount Treads
A frame to mount the treads to and hold the motors and electronics must be constructed. The design will
be simple and fabrication easy, so this should not take a long time to complete. The size of the frame will
be determined by the need for a router and the size of the metal detector. The metal detector may also
affect the form of the frame. In order to complete this step, the size and shape of the metal detector must
be known.
2.3.2.7
Test Humidity Sensor and Sonar
The humidity and temperature sensor and the pinger sonar should both be fairly simple sensors to
implement in the robot design. Therefore, testing them and making sure they work according to design
specification should be completed early to move on to more complex aspects of the electronic sensor
system.
2.3.2.8
Create GUI Framework
The GUI will mux all the sensors into an aesthetically pleasing view and control system for the user. The
framework for this needs to be completed to allow for seamless incorporation of the sensors once
complete.
2.3.2.9
Develop Movement and Motor Controls
Once the tracks and motors have been mounted to the frame, the control system will be implemented and
the movement of the robot will be tested. The robot should be able to go forward, backward, and be able
to turn on point. The control system will be tested to ensure that all of these motions are possible and that
the interface is logical and easy to control the robot with. Its ability to overcome minor obstacles will be
tested by driving it over rough ground and small objects.
2.3.2.10 Finalize Buoyancy
The buoyancy of the robot will be tested by removing the motors from the frame, adding weights that will
be equivalent to the weight of the motors and electronics, and attaching the sled form to the bottom and
filling it with foam. It will then be placed in the water and the buoyancy will be adjusted to ensure that it
floats and that the water hits the treads at an ideal location for paddling. Once the robot is buoyant, the
motors will be reattached and its ability to propel and maneuver itself on water will be tested.
8
2.3.2.11 Finalize and Test Metal Detector
Once the metal detector has been acquired, it will have to be configured with the Raspberry Pi to ensure
compatibility with the computer. Once this has been connected, a great deal of tuning and testing will be
required to ensure the metal detector has sufficient range and sensitivity for the depths Amphibot will be
searching.
2.3.2.12 Combine and Test Sensors
Once each sensor has been acquired and tested separately, it will be important to ensure that they are all
compatible with one another and can run simultaneously on the Raspberry Pi. This stage involves making
sure that all the sensors in the electrical system work as expected in real time without straining the
Raspberry Pi system and work over the Wi-Fi network.
2.3.2.13 Interface with GUI
Once the sensors have been proven to be able to work independently, they need to be able to
communicate with the GUI to give the user a friendly environment to work in. This is critical in the final
presentation of the design. In order for this to work, the Raspberry Pi needs to transmit the necessary data
to the GUI application over the Wi-Fi network for the user to see.
2.3.2.14 Mount Electronics into Robot Body
The hardware and sensor for the body of the robot will be waterproofed and mounted in the robot. The
functionality of the sensors in different environments will be tested by putting the robot in a pool that has
metallic objects placed in the bottom and determining whether it can sense them. The hardware will be
tested by pinging the coordinates of the robot and maneuvering it on the water and on land. In order for
this milestone to be completed, the electronics must be ready to be placed in the robot and the software
must be completed. These components will still be accessible to make alterations.
2.3.2.15 Create an Android App
In order to make Amphibot more ideal for the user, an Android application will be developed to allow the
user to control Amphibot from an Android phone. This is not necessary as Amphibot will be able to be
controlled from the Windows application using a laptop as well. However, this is ideal for testing
purposes and fulfilling the design norm of delightful harmony as people are more likely to carry a phone
than laptop when outdoors.
2.3.2.16 Build Cover and Complete Robot Assembly
The plastic cover will be constructed for the robot and it will be attached to the body. Its ability to keep
out water will be tested by slowly increasing the amount of water splashed onto it and using the humidity
sensor to read if any water has breached the waterproof box. The cover will also be opened to visually
determine if any water has entered the main body of the robot. If any water has gotten in, the leak will be
found and fixed.
2.3.2.17 Test Robot and Make Final Alterations
The robot will go through its final testing phase where the team will determine if the requirements have
been met. It will be driven on a track to determine the distance it can travel. It will be placed in a pool to
determine its maneuverability and whether it can sense objects. It will be driven into a pond to see if it
can make the transition between land and water. It will be driven through tall grass and mud to test its
ability to traverse multiple terrains. Through all of this it will be controlled through the designed interface
9
and its location will be pinged with GPS. If any of the requirements are not met, alterations will be made
and the robot will be tested again.
2.3.2.18 Prepare Senior Design Night Presentation
Calvin College hosts a Senior Design Night in May to display each senior design team and their
accomplishments. At this event, Team 11 will be demonstrating the Amphibot prototype as well as giving
a presentation summarizing their work and accomplishments for the project in the previous several
months.
2.3.2.19 Complete All Senior Design Deliverables
The Senior Design capstone includes a number of deliverables, such as a Final Design Report, team
notebooks, and in-class presentations. The team will be including these deliverables into its work
breakdown schedule once the official due dates are known.
10
3
Project Clarification
In order to better design the Amphibot vehicle, Team 11 had to clarify the scope and requirements of the
project. The team developed a problem specification and target customer that helped to narrow the design
of the robot. Once the design was determined, the team could set requirements for form, function, and
use.
3.1
Problem Specification
People who spend a lot of time around water are bound to lose something expensive or important in that
water at some point. Especially in water like swamps, marshes, ponds, and other dark, shallow, muddy
water, these items could be easily retrieved if only they could be easily located. But for most people,
wading or swimming in dirty water for a pair of dropped sunglasses is not worth the effort. Amphibot is
designed to alleviate some of the hardship of losing things to the water. It can find metal objects in
shallow water, letting its user know exactly where the lost item is for quick and easy retrieval by hand or
net. This relieves the stress and difficulty of finding lost items.
3.2
Customer
The robot, Amphibot, was designed to be applicable primarily for hobbyists, fishermen, and amateur
boaters. Outdoorsmen and women who spend time on the water know that nothing is as frustrating as
losing a pair of expensive sunglasses, a beloved piece of jewelry, or the car keys. Sometimes these items
can be found, but often it is impossible to find the items once they have gone beneath the water into the
mud. Such customers will find Amphibot makes their lives easier, allowing them to easily scoop up lost
items without sifting through mud, wading through dirty water, or dealing with any local wildlife.
Amphibot is useful for the same reasons to local sheriffs who need to find discarded weapons like guns or
knives, or find the location of a wrecked car in a pond.
3.3
Requirements
Team 11 has developed a list of requirements that will allow Amphibot to perform its specified function
in a way that is easy, useful, and helpful to its end user. These requirements are divided into categories of
performance, physicality, electronics, interface, and cost.
3.3.1
Performance Requirements
Amphibot’s performance requirements determine how well it will function. Amphibot’s functionality is
designed to balance being useful to a user by having adequate performance with being low cost, simple,
and easy to replicate.
3.3.1.1
Driving Requirements
REQ3.3.1.1.a The robot will be able to traverse 0.25 miles on a single battery charge.
REQ3.3.1.1.b The robot will be able to travel on dry surfaces, wet, marshy surfaces, and on the surface of
still water.
3.3.1.2
Sensing Depth Requirements
REQ3.3.1.2 The robot will be equipped with sensors which produce valid data to a depth of at least 3 feet.
11
3.3.2
Physical Requirements
Physical requirements for Amphibot are based primarily on what the end user would be likely to want in a
personal sized robot in terms of size and maneuverability. In general, size limitations represent
maximums, as the robot’s size is to be as small as the components will allow.
3.3.2.1
Size Requirements
REQ3.3.2.1 The robot will be constrained to fit within a 3 feet sphere in order to allow for ease of
transport and to provide the most flexibility to the user.
3.3.2.2
Weight Requirements
REQ3.3.2.2 The robot will weigh no more than 50 pounds. This is a manageable weight for a human to
transport for short durations.
3.3.2.3
Speed Requirements
REQ3.3.2.3 The robot must be able to travel at least 2 mph. This is a pace that is reasonable for travel
while being slow enough for sensors to work and the user to steer.
3.3.2.4
Maneuverability Requirements
REQ3.3.2.4 The robot must be able to go in forward and reverse directions. It must be able to turn within
a 3 foot radius in order to be able to maneuver through the tight spaces that it will encounter.
3.3.3
Electronic Requirements
Amphibot’s electrical systems need to be robust enough to stand up to motion, transport, and wet
environments without breaking or needing replacement. The system needs to be able to properly interface
with the mechanical system via motor servos and to interface with the user via the wireless area network.
Each sensor must behave according to specifications determined by how Amphibot is designed to be
used. A block diagram of the electrical system, which displays all input and outputs as well as how they
are connected to one another, is shown in Figure 2 below.
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Figure 2: Electronic Block Diagram
3.3.3.1
Sensor Requirements
REQ3.3.3.1.a The robot will provide metal detection that is accurate to identify metallic objects as small
as a quarter up to 3 feet away.
REQ3.3.3.1.b The robot will utilize sonar to provide the user with water depth accurate between the
ranges of 6 inches and 3 feet.
REQ3.3.3.1.c The robot will be able to communicate its GPS coordinates to a user when it has identified
an object.
REQ3.3.3.1.d The robot will provide live video feed to allow for steering without direct line of sight.
3.3.3.2
Communication Requirements
REQ3.3.3.2 The robot will communicate over a local area network provided by a router installed on the
robot. The network will connect to the user via Wi-Fi, and will operate within a range of a quarter mile.
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3.3.4
Interface Requirements
Once the robot is connected to a user’s phone or laptop, the user interface will be intuitive to use, made
with a clean design, and easy to understand.
3.3.4.1
Control Requirements
REQ3.3.4.1.a The interface will allow for moving in the X and Y plane, control speed, and provide the
user with sensor data.
REQ3.3.4.1.b The data provided by the sensors will provide simple information to the user without
requiring tuning or calculations.
3.3.4.2
Graphics Requirements
REQ3.3.4.2 The Graphical User Interface must be clean and easily understandable for a lay-person to use.
3.3.5
Cost Requirements
In determining cost, a consideration of the customer’s demographic and resources determined the upper
limit of what could be charged for the end product. In determining prototype costs, parts could cost no
more than allowed by the senior design budget.
3.3.5.1
End User Cost
REQ3.3.5.1 The completed Amphibot must be cheap enough for an amateur hobbyist’s budget. It must
cost an end user no more than $1000.
3.3.5.2
Prototype Cost
REQ3.3.5.2 The Amphibot prototype will cost no more than $500.
3.4
Deliverables
Because the senior design project represents a capstone class in the Calvin College Engineering
department, there are a number of project deliverables that are due to the faculty advisors for grading.
These are outlined below.
3.4.1
Fall Semester Deliverables
The following deliverables represent the critical graded tasks of the senior design project during the fall
semester.
3.4.1.1
PPFS
Team Amphibot will submit a Project Proposal and Feasibility Study describing the proposed project and
determining the feasibility of it at the end of the fall semester of 2014.
3.4.1.2
Team Website
Team Amphibot created and published a team website during the fall semester of 2014 describing the
team, project, and important documents. This website will be updated throughout the span of the project.
3.4.1.3
Team Poster
Team Amphibot created a preliminary poster in the fall semester of 2014 and will complete a final poster
to be displayed in the spring semester of 2015.
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3.4.2
Spring Semester Deliverables
The following deliverables represent the critical tasks due to the senior design class for the spring
semester.
3.4.2.1
Final Report
Team Amphibot will submit a final report specifying the final design specifications at the end of the
spring semester of 2015.
3.4.2.2
Working Prototype
Team Amphibot will present a working prototype at Senior Design Night on May 9, 2015.
3.4.2.3
Design Notebooks
Team Amphibot will submit individual design notebooks specifying each member’s contributions to the
project at the end of the spring semester of 2015.
3.4.2.4
Final Presentation
Team Amphibot will present the results of their project on Senior Design Night on May 9, 2015.
15
4
Design
With a specific problem to solve and a list of requirements, Team 11 researched necessary components
and their specifications in order to settle on a final design for Amphibot. This design was made by a
careful consideration of the problem, the customer, and feasibility based on research, as well as on a list
of important criteria and the team’s design norms. In the sections following, the team spells out driving
design criteria, explains the three design norms most relevant to the design, and summarizes its research
and chosen design.
4.1
Design Criteria
The design decisions were made based on key criteria that were deemed important to the team as the
designer and important to the customer as the end user. These criteria are explained here.
4.1.1
Critical Considerations
Critical considerations are the variety of factors that the team needed to take into consideration when
determining its final design choices. These factors were based on user operation, operating conditions,
and design limitations.
4.1.1.1
Weight
In order to maintain battery life and buoyancy, the materials and components used must be as light as
possible. As the weight of Amphibot increases more power must be utilized to propel it forward.
Additionally, a heavier product would be less desirable to an end user for transportation purposes.
4.1.1.2
Durability
The robot will be travelling through harsh conditions. In order to maintain the life span of Amphibot, the
components must be able to withstand jarring impacts, moisture, and dirt. Electronics should be
waterproof where needed and water resistant where possible.
4.1.1.3
Simplicity
In order to prevent breakage and make Amphibot easier to fix and customize, the systems must be as
simple as possible while still performing required functions.
4.1.1.4
Transportability
Since Amphibot will be used in boats, it should be small enough to fit in an average small boat without
trouble. It should also be compact and light enough that it can be carried by a single person to transport it
between a boat and a vehicle, dock, or garage.
4.1.1.5
Reliability
Amphibot will be travelling in hard-to-reach areas with only wireless control. This runs the risk of losing
the robot in difficult areas to navigate. This risk should be minimized, so each component must be as
reliable as possible. Electronic components need to be able to function quickly and well regardless of
situation and location. Mechanical components must not break when performing intended functions.
4.1.1.6
Maneuverability
Amphibot must be easy to maneuver. This is important because the user will be steering by control
buttons based on video feed and will not be able to physically make corrections to the robot’s path. It will
also need to be capable of travelling through tight spaces and go around large obstacles.
16
4.1.1.7
Versatility
Amphibot will be required to traverse a broad range of environments from land to water, including rocky
and marshy areas. The robot’s propulsion system must be able to travel through each of these. Amphibot
must also be versatile with regard to the customer’s needs from sensors and other performance related
requirements.
4.1.2
Design Norms
The three design norms that will be emphasized in our project are delightful harmony, trust, and caring.
4.1.2.1
Delightful Harmony
People who fish and boat for a hobby regularly do so to relax, relieve stress, and enjoy themselves.
Losing something valuable is an easy way to lose the positive benefit provided by these enjoyable
pastimes. Amphibot is designed to lighten that stress and provide other sources of enjoyment. Therefore,
Amphibot will be aesthetically pleasing and easy to use.
4.1.2.2
Caring
Amphibot is designed to minimize or eliminate otherwise unpleasant human tasks. Wading through
swamps can be cold, wet, and muddy, and especially in areas in the south, can be home to wild alligators
and dangerous animals. Amphibot makes the task of searching for lost items easy and harmless.
4.1.2.3
Trust
People using Amphibot need to be able to trust that the system will work properly every time. Users
should be able to trust the product and be able to have faith in its reliability. Additionally, they need to
trust the team as designers. The end user is considered in every aspect of the design process. This will be
visible in the durability and usefulness of the final prototype.
4.2
Propulsion System
Various methods of propulsion were considered for Amphibot. The challenges of propulsion came from
Amphibot’s amphibious nature, which required a method of propulsion for both land movement and
movement along the surface of the water. Additionally, the land around the waterways that Amphibot is
likely to be traversing would be both muddy and full of debris like rocks, marsh grass, leaves, sticks, and
other plant life.
4.2.1
Alternatives and Research
In determining the final design, many different propulsion methods were considered. These included
integrated systems where one system would power Amphibot along both mediums and separate systems
which utilize a different propulsion method for land and water traversal.
4.2.1.1
Integrated Systems
Integrated systems are propulsion systems that are capable of moving across both land and the surface of
the water using the same mechanical component.
4.2.1.1.1 Screw-Propulsion
In this system the robot would be propelled by two large power screws located on either side of the body.
If the interiors are hollow, it would provide the buoyancy needed to float on water and stay on top of mud.
This system would allow the robot to travel through marshy environments. Screw-propulsion is a more
17
recent development that is not commonly used. It is hard to maneuver and has problems with slippage.1
The parts needed are also more expensive and harder to obtain. An example of screw-propulsion is shown
in Figure 3.
Figure 3: Screw Propulsion2
4.2.1.1.2 Tracks
Tracks are an ideal way to travel across rough terrain. Modifications must be made in order to make them
suitable to drive on water. Small paddles are mounted on the treads. These can be in the form of paddles
that fold down when on land and open when in water, shown in Figure 4, rubber paddles that are small
enough to allow land travel but large enough to have significant traction when in the water, or foam
paddles that provide buoyancy and propel the robot forward, as shown in Figure 5.
Figure 4: Foldable Paddles3
18
Figure 5: Foam Treads4
Having paddles that fold down would provide a way to travel more efficiently on land and on water. The
drawbacks to this system are that it would require the switching of two levers - one for each track - and
the joints for the paddles could easily become jammed with mud. If the paddles are jammed, it would
throw the robot off balance and possibly cause the paddle to break. The rubber paddles would not be as
efficient as the foldable paddles but would still provide suitable motion for land and water. The rubber
would be durable and able to grip, while the deep tread would be well suited for muddy areas and
paddling through water. The foam paddles would allow travel on land and solve the problem of buoyancy
in the water, but they would not be very durable or provide much traction on land or in the water because
of the thickness required to make them sturdy. The foam is also light and could result in the robot being
top heavy.
4.2.1.1.3 Paddled Wheels
A final option for an integrated propulsion system would be to use paddled wheels, as demonstrated in
Figure 6. The paddles would be similar to the rubber paddles mentioned in the section above. The benefits
to this would be easy maneuverability. The negative is that the wheels are more likely to get stuck in the
mud or not be able to overcome obstacles.
Figure 6: Paddled Wheels5
19
4.2.1.2
Separate Systems
Propelling Amphibot by separate systems means finding a system that works well for land, a system that
works well for water, and combining the two systems into a single design.
4.2.1.2.1 Propeller
Each of these systems uses a propeller and some other method of travelling on land. Using a propeller like
the one in Figure 7 is the most efficient way to propel the robot through water. A single propeller could be
mounted on the back of the robot. A rudder would then be used to steer. Having a propeller would require
another motor, adding weight, and another control system, adding complexity. Transitioning between land
and water would also be more problematic.
Figure 7: Propeller6
4.2.1.2.2 Crawler and Propeller
A crawling system, would make use of legs. There are many possibilities for leg structures and
positioning. All are driven by rotational motion. In one system multiple sets of legs are moved by rocker
arm mechanisms. In another, designed by NASA and shown in Figure 8, two beams are connected, one
long and one short, using a gearing mechanism so that as the first leg rotates, the second, shorter leg helps
to propel the robot forward.7 The motion resulting from this is complicated and jarring. The benefit of
legs is that in mud, they will not spin out. Drawbacks are that this system is unstable and maneuvering is
complicated.
20
Figure 8: NASA Crawler8
4.2.1.2.3 Wheels and Propeller
In a wheel and propeller system, the wheels would provide high maneuverability and allow higher speeds,
especially when there are no paddles attached. They still have the problem of being easily stuck in mud
and having a more difficult time in overcoming obstacles. The Duck Boat, shown in Figure 9, is an
example of such a system.
Figure 9: Duck Boat9
4.2.1.2.4 Tracks and Propeller
The tracks would allow for decent speeds on land and do well in overcoming obstacles. This in
combination with the propeller would provide reliable and efficient motion both on land and in the water.
Figure 10 shows an example of this system. One negative is that the tracks would create strong drag when
being pushed through the water and hinder maneuverability.
21
Figure 10: Tracks10
4.2.2
Decision
The robot will be propelled by tracks on land and on the water. They will be constructed using treadmill
belt material with rubber grips attached. The grips will be long enough and spaced far enough apart that
they will produce sufficient motion both when in the water and on land. The front and back of the tracks
will be angled upward in order to better overcome obstacles on land whether going forward or backward.
This configuration also gives more flexibility when considering the buoyancy of the robot. The water
level must not be higher than the top of the tracks, but the body of the robot must still be high enough to
clear obstacles when travelling on land. The tracks will be propelled using an electric motor that drives a
pressure wheel that will turn the tracks. This will allow the belt to be taken off easily and prevent
slippage. The length of the tracks is 1.6 times the width of the body in order to optimize traction and
maneuverability. See Figure 11 below.
Figure 11: Amphibot Treads
There will be two electric motors located on each side of the robot to drive the tracks. Each will be
reversible and controlled separately. This will allow the robot’s position to be easily controlled by
determining the speed and direction of each of the tracks separately. These motors must be able to provide
22
a minimum of 25 Watts in order to be able to propel the robot at reasonable speeds and power it over
obstacles.
4.3
Materials
An important decision was the materials that would be used for the different components of the robot.
4.3.1
Alternatives and Research
Each material option was evaluated for cost, weight, and strength. The application it would be used for
was also considered in order to make a decision on which materials to use.
4.3.1.1
Aluminum
Aluminum as a structural material would be ideal because it is light-weight. A drawback is that it is not as
strong as steel. It would, however, be strong enough to withstand the forces the robot will be
experiencing.
4.3.1.2
Steel
Steel is stronger than aluminum and is also denser. As a structural material it would add significant
weight while adding strength that isn’t required.
4.3.1.3
Plastic
Plastic is a light-weight, easily molded material that is ideal for the robot casing. It can absorb shock and
keep out particles. As a structural material, it would be light, but would require more volume to meet the
required strength.
4.3.1.4
PVC
PVC piping as a structural component would add buoyancy. It would, however, be bulky and harder to
attach components to. It also would not allow much flexibility when adjusting the height the robot sits at
in the water.
4.3.1.5
Foam
Foam to make the robot float is light-weight and easy to apply. Liquid foam, like that shown in Figure 12,
is easily moldable and can fit into crevices. Foam sheets can easily be cut into geometric forms and
removed from the robot. Both types come in a variety of densities. The foam could easily be scraped off
or added to in order to adjust buoyancy. A negative is that foam may chip off during use of the robot.
Figure 12: Liquid Foam11
23
4.3.1.6
Rubber
Rubber is a heavy material, but ideal for the tracks because it is flexible and has strong gripping
capabilities. This is important on land because there will not be as much contacting surface area because
of the elongated treads. Recycling tires is difficult and rubber needed by the team can be cheaply obtained
by collecting used tires, see Figure 12, and reusing them. This would be helpful to the environment by
reducing waste.
Figure 13: Used Tires12
4.3.2
Decision
Aluminum will be used for the structure because it is low density and sufficiently strong to withstand the
forces that Amphibot will experience. Plastic will be used for the casing because it is light and easily
moldable. It will also be able to withstand moderate impacts that Amphibot may experience. Foam will be
used for buoyancy in the bottom of the body of the robot. If water seeps into the body of the robot, it will
not be able to penetrate the foam and the robot will continue to float. Rubber will be used for the treads
because of its traction and ability to bend, so that it will not break. Recycled tires will be used as an act of
stewardship.
4.4
Body
The body of the robot will contain all of the electronics and motors. It must be durable and water resistant
in order to protect the components and prolong the life of the robot.
4.4.1
Structure
The main structure will be composed of 1 in by 1/8 inch aluminum bars. These bars will be bolted
together to allow easy alterations. The components will also be bolted to the structure so that they can be
removed if the need arises. The structure will be a basic box with a cross structure in the bottom. The
tracks will be mounted to the sides of the box and the motors will be mounted inside of the box. The bars
will be bent at 90 degrees to increase the strength in torsion and provide surfaces to mount components to.
The structural design can be seen in Figure 14.
24
Figure 14: Preliminary Frame Design
4.4.2
Casing
The entire body will be surrounded by a plastic casing in order to prevent foreign objects from jamming
inside of the robot. The greatest concern is mud during the transition periods between land and water. The
casing will have a clear window to allow the camera to view the environment in front of the robot. It will
be easy to remove so that the batteries can be easily replaced. The bottom of the robot will be protected
by a plastic layer that will act as a sled to allow the treads to easily drag the robot through thick mud and
weeds without foreign matter getting jammed into the robot’s body. This sled will also protect the foam
layer and help with buoyancy. The tracks will also have a plastic, exterior barrier mounted on them to
prevent objects from jamming in the wheels and hindering movement.
4.4.3
Dry Box
A dry box such as in Figure 15 will be used to hold the electrical components. This box is small, light,
and designed specifically to protect items from moisture. There is a set of latches that allow access to it,
which will be ideal for prototyping and maintenance. This will also allow access to the batteries, which
will need periodic charging. Holes will have to be drilled into the side of the box in order to connect wires
to the motors, webcam, sonar, and metal detector. These holes will be caulked shut in order to maintain
the waterproof qualities of the box.
25
Figure 15: Dry Box13
4.4.4
Layout
The central body of the robot will be a combination of waterproof and non-waterproof electrical
components. The non-waterproof components will be placed in a waterproof box. The waterproof
components will be placed on the frame of the robot in a manner that equally distributes the weight so
that the robot will remain level when on water. The buoyancy of the robot will be obtained by lining the
bottom on the body with foam. A liquid foam of 4lb will be used because it is flexible and easy to form
while providing enough upward force in the water to maintain the robot at desired levels. The conceptual
layout can be seen in Figure 16.
Figure 16: Amphibot Preliminary Layout
26
4.4.5
Size
The estimated weight of the robot is 30 lbs. The length of the tracks is 1 ½ ft. and the width is 4 in. The
width of the body is 1 ft. This will allow it to be transportable while being large enough to carry its
required load and easily overcome small obstacles.
4.5
Onboard Computer
In order to run the sensors, control the motors, and interact with the end user, Amphibot needs an onboard
computer to serve as its processing unit and manage these interactions. Because of size limitations, a
single-board computer is the perfect embedded system for Amphibot.
4.5.1
Alternatives and Research
There are many single-board computers on the market, most of them small and relatively inexpensive for
use in small projects with mild processing requirements. In order to select the best option for Amphibot,
Team 11 researched some of the more popular single-board computers on the market.
4.5.1.1
Raspberry Pi
The Raspberry Pi single-board computer is the most popular on the market. It has one of the cheapest
prices for single-board computers with adequate memory and processing power. In addition to its low
price, Raspberry Pi has the largest support forum of any single-board computer on the market due to its
open-source coding and wide fan base in the do-it-yourself market. This contributes to a great deal of
support to troubleshooting and coding. The Raspberry Pi comes in 4 models: A, A+, B, and B+, pictured
in Figure 17 below. All use a 700MHz ARM11 family CPU and a 250MHz Broadcom VideoCore IV
GPU. A models have 256MB of SDRAM memory while the B models have 512MB. The plus models
have a greater number of GPIO ports. All models have between 1 and 4 USB drives. They range in price
from 20 to 35 dollars.14
Figure 17: The Raspberry Pi B+15
4.5.1.2
Arduino Mega
Arduino is a family of microcontrollers that come in many, many varieties for a number of uses. The
Arduino Mega2560 and the Arduino Uno are two of the more popular boards. Arduino makes
microprocessors, which differ from single-board computers by their lack of GPUs and graphical user
27
interfaces. They also tend to be weaker in general functionality, as they specialize in performing specific
tasks. The Arduino Mega2560 has a 16MHz processor, 256 GPIO pins, and sells for 43 dollars.16
4.5.1.3
BeagleBone
The BeagleBoard single-board computer is produced by Texas Instruments. BeagleBoard has some of the
best functionality for open-source, low power, single-board computers, but it is also one of the more
expensive. The BeagleBone and the BeagleBone Black, pictured in Figure 18, are two recently launched
BeagleBoard computers. They have a 720MHz processor and 256 and 512MB RAM, respectively. It is
priced at 55 dollars.17
Figure 18: The BeagleBone Black18
4.5.2
Decision
The Raspberry Pi B+, was chosen for use in Amphibot. This decision was made for its price, size and
community. It was cheap and small which are some of our constraint concerns. The Raspberry Pi was
easy to acquire on short notice and start working with immediately due to the number of Raspberry Pis
owned by Calvin College. Additionally, as beginners in embedded systems, the vast amount of online
forums and assistance played a large role in the ultimate decision.
4.6
Remote Communication
In order to communicate with Amphibot, the user will need to use remote communication. The
communication needs to be able to allow the user to control Amphibot from a distance. Some challenges
for communication were allowing for a large enough range and having a reliable connection.
4.6.1
Alternatives and Research
A range of communication protocols were researched for use with Amphibot.
4.6.1.1
Wi-Fi
Wi-Fi, see Figure 19, is the most commonly used local area wireless technology.19 It allows for data
transmission via an electronic device such as a router or switch. It is usually used within a home to
connect and allow portable devices to connect to the Internet. Out of all the wireless communications
protocols, it has the largest range, able to connect up to 20 meters indoors and further outdoors.
28
Figure 19: Wifi20
4.6.1.2
Ethernet
Ethernet would be ideal for Amphibot because it is the most secure and reliable. Since it is a wired LAN
connection, there is no question whether the data is being transmitted. The wired connection, however,
poses problems for Amphibot and its proximity to water. The range of motion for Amphibot would be
limited by the length of the Ethernet cable. The Raspberry Pi has Ethernet readily available making it
more ideal for use.
4.6.1.3
Bluetooth
Bluetooth, see Figure 20, is another common form of wireless communication. It follows certain
standards set by IEEE and devices must meet these in order to be certified Bluetooth capable. Bluetooth
has low power consumption but can only connect in short distances, approximately 10 m.21 Because it is
radio communication, it does not require line-of-sight to exchange data. This would be ideal if there are
obstacles between the user and Amphibot.
Figure 20: Bluetooth22
4.6.1.4
Zigbee
Zigbee, see Figure 21, is similar to Wi-Fi and Bluetooth in that it is a wireless personal area network. It is
the only wireless protocol to be open, global and provide the Internet of Things.23 Like Bluetooth, it has
low-power consumption and a shorter range. It is designed for applications requiring security and long
battery life. Like Bluetooth, Zigbee only has a range of 10m to 100m with line-of-slight. However, it is
simpler and cheaper than Wi-Fi and Bluetooth.
Figure 21: Zigbee24
4.6.2
Decision
It was decided for Amphibot that Wi-Fi would be used as the mode of data exchange. It will be
implemented using a router to create a WLAN (wireless local area network) between the Raspberry Pi
and Wi-Fi Dongle in the Raspberry Pi USB port and user. Wi-Fi will allow Amphibot to meet the
29
required range of motion of a quarter mile. It is also widely used, making it easy to implement and
reliable. Wi-Fi will allow us to secure the network and prevent unwanted hacking of Amphibot.
4.7
Sensors
Amphibot will take data from the world around it primarily by use of sensors in the drop-down sensor
box. These sensors will be controlled using the onboard computer.
4.7.1
Global Positioning System (GPS)
A GPS will be used on Amphibot to relay back to the user the position of any discovered items. It will
also help the user know where Amphibot is as the GPS coordinates will be relayed back to the user
continuously.
4.7.1.1
Alternatives and Research
The main implementations for GPS in Amphibot researched were a handheld GPS Unit, a USB GPS
Receiver, and a GPS receiver circuit. All of these were researched before a final decision was made.
4.7.1.1.1 Handheld GPS Unit
A handheld GSP Unit would be a portable device that would attach to Amphibot and then report the
results back to the user via an application. These devices, being built for a user to hold, are equipped with
features, like an LCD screen, that are of no use in Amphibot. These devices use satellite and would have
high accuracy.25 Most devices cost a few hundred dollars.
4.7.1.1.2 USB GPS Receiver
A USB GPS Receiver would be able to connect directly to a USB port on the Raspberry Pi.26 Since these
devices are mainly an antenna, it reduces the cost drastically to be in the range of 10 to 30 dollars. The
receiver would not be able to function with the Raspberry Pi, so conversion of raw data to coordinates
would need to be taken care of by the user device.
4.7.1.1.3 GPS Receiver Circuit
Adafruit sells a circuit board able to connect with single-board computers and micro controllers like
Arduino and Raspberry Pi. The Adafruit Ultimate GPS, pictured in Figure 22, has battery power
capability and an output for an antenna extension.27 Adafruit provides easy-to-use setup instructions and
tutorials for basic usage. It sells for a moderate price of 40 dollars for the circuitry and 13 dollars for the
external antenna.
30
Figure 22: Adafruit Ultimate GPS28
4.7.1.2
Decision
The Adafruit Ultimate GPS with antenna extension was determined to be the best GPS unit for Amphibot.
It was chosen mainly for its ability to be supported by the Raspberry Pi. Rather than have the data
conversion be handled by the user’s device, all conversions should be handled by the Raspberry Pi so as
to make the process not dependent on user device.
4.7.2
Onboard Camera
Amphibot will use an onboard camera mounted on the front of the bot to give the user a proper field of
vision for steering Amphibot remotely. Implementing such a camera gives the user the freedom to drive
Amphibot around corners or into areas the user cannot see directly.
4.7.2.1
Alternatives and Research
There are a variety of cameras on the market that are compatible with most single-board computers. In
order to determine which would be the best option to use on Amphibot, compatibility, size, and price
were predominate factors considered during research.
4.7.2.1.1 Webcam
The market is full of various types, sizes, and quality of webcams. Typically, webcams connect to a
computer via USB and are used to stream live video over a network. The benefit of a webcam for use in
Amphibot is its small size, cheap price, and variability available in resolution, lens angle, and frame rate.
Webcams can be used on almost any computer platform, so there were very few compatibility issues.
However, a webcam is not usually waterproof, as their primary function is for video chatting and web
conferencing. Therefore, some method of sealing or waterproofing would have to be utilized in case of
submersion or splashing.29
The webcam determined to be the best option for Amphibot was the Creative Live! Cam Sync HD,
pictured in Figure 23. This is a good balance of good image quality, good lens angle, small size, and
31
affordable price. It was also determined to be well-compatible with Raspberry Pi and other single-board
computers.30
Figure 23: Creative Webcam31
4.7.2.1.2 Security System Camera
Many people choose to incorporate their own home monitoring systems, whether for security, for
personal interest, or for keeping an eye on elderly or special needs family members living alone. There is
a sizeable market of high-quality security system cameras, many of which are water resistant for use outof-doors. These cameras are also often equipped with infrared LEDs to allow for night monitoring as
well. The downside of implementing a security system camera on Amphibot is its relatively large size, as
well as its fairly expensive cost. Additionally, there was concern with easy compatibility with the onboard computer.32
4.7.2.1.3 GoPro
GoPro cameras have become a sensation because of their extreme waterproofing, high quality images,
and durability. They are often used in extreme sports as point-of-view cameras, and are often installed on
robots due to their small size, easy use, and difficulty to break. A GoPro camera would be the ideal
camera for our use as well. However, the cameras are expensive, costing over one hundred dollars for the
cheapest version, pictured in Figure 24.33
32
Figure 24: GoPro Hero34
4.7.2.2
Decision
A USB webcam was determined to be the best option for use on Amphibot. It is easy to implement and
simple to use, and costs and weighs little. In order to waterproof the webcam, the team will be cutting a
small window in the waterproof electronic box and caulking a piece of clear plastic or glass in its place.
This will give the webcam a peephole to the outside, and allow the team to implement its functionality
without worrying about water damage.
4.7.3
Humidity and Temperature Sensor
In order to monitor the electronics remotely, the humidity and temperature inside the electronics box will
be monitored to ensure neither value goes into unsafe ranges for electronics.
4.7.3.1
Alternatives and Research
The alternatives for temperature and humidity sensors mostly consisted of the decision of whether to
utilize an all-in-one sensor that would be able to take data in both fields or to use two separate sensors
which are designed to do one set of data collection very well.
4.7.3.1.1 Combined Temperature and Humidity Sensor
The DHT22, pictured in Figure 25, is a small digital temperature and humidity sensor. It is approximately
the size of a quarter, and weighs very little. It is able to sense all humidity levels with a 2-5% accuracy
and can read temperatures between 0 and 80 degrees Celsius. It is able to sample only once per 2
seconds.35
33
Figure 25: DHT22 Sensor36
4.7.3.1.2 Separate Temperature and Humidity Sensors
When components are combined, they have the potential to lose functionality. In order to increase
accuracy, it would be possible to implement separate humidity and temperature sensors. The HH10D can
detect humidity levels with only a 3% error, marginally better than the combined system,37 and the
TMP36 can detect temperatures in the range of -40 to 125 degrees Celsius with only 2 degrees of error.38
4.7.3.2
Decision
The DHT22 was chosen because of its small size, its price, and ease of use. It was determined that the
error was acceptable, and that implementing two systems was not worth the marginal gain in accuracy.
4.7.4
Sonar
Sonar will be used on Amphibot to aid the user in knowing the depth of the water at a given spot. This
will allow the user to better determine the best method of retrieval.
4.7.4.1
Alternatives and Research
Various methods of sonar and depth sensing technology were researched for implementation in
Amphibot. The two main design potentials were side-scan sonars and ultrasonic pingers.
4.7.4.1.1 Side-Scan Sonar
Side-scan sonar is used to create images of the sea floor, as in Figure 26. It is largely used to aid in
finding shipwrecks. It uses cone shaped pulses aimed at the see floor to detect changes in the reflection
off objects. It would be hard to implement in Amphibot. Good quality sonars are not waterproof and
would require addition home-waterproofing techniques before being able to be functional in Amphibot.
34
Figure 26: Side Scan Sonar39
4.7.4.1.2 Ultrasonic Pinger
An ultrasonic pinger sends out sound waves to determine the depth based on the echo of the sound. It is
ideal for Amphibot in that it is an easy way to determine the depth of the body of water at a specific
location.
4.7.4.2
Decision
For Amphibot, it was decided that an ultrasonic pinger would be sufficient to cover the necessary feature
needed from sonar. In the case that metal detection is not feasible, side-scan sonar will be implemented as
the main tool to find objects.
4.7.5
Metal Detection
The metal detector represents the key sensor on Amphibot. It is what ultimately is used to solve the
problem statement of finding lost items in black-water. Therefore, it is very important that the metal
detector function well.
4.7.5.1
Alternatives and Research
There are two main types of metal detectors that work in water. These are Pulse Induction (PI) metal
detectors and Very Low Frequency (VLF) metal detectors.40
4.7.5.1.1 Pulse Induction Metal Detectors
Pulse induction metal detectors use a single coil of wire for transmitting and receiving signal. The
transmit frequency of a PI is around 100 pulses per second, with lower frequencies achieving greater
depth and experiencing greater sensitivities to silver and higher frequencies achieving more sensitivity to
gold and nickel alloys. PI is not capable of great discrimination. That is, PI metal detectors cannot easily
be programmed to not respond to specific metals. However, they are good for detecting metal through
deeper salt water, and for searching mineralized ground.41
35
4.7.5.1.2 Very Low Frequency Metal Detectors
Very Low Frequency is the most common metal detector technology at present. It uses two coils, a
transmitter coil and a receiver coil, to detect metal based on interference with the electric fields generated
and received. VLF can be adapted to discriminate between different types of metals, like silver and
aluminum, which is useful for treasure hunters seeking precious metal from areas with metallic debris in
the area. When combined with a microprocessor, VLF can be easily programmed to search for certain
types of metal, like silver, iron, or steel.42
4.7.5.2
Decision
The difficulty of implementing a metal detector begins with the difficulty of implementing the required
range. Small, 10-12 inch depth sensitive metal detectors are simple to implement,43 but finding a way to
balance the sensitivity and the depth will be difficult to accomplish while still balancing our size, cost,
and power requirements.
Because of its ability to ignore ferrous sand, earth, and mud, as well as salt water, without losing its
sensitivity to metallic objects, a PI detector is a better choice to attempt to implement in Amphibot. The
team will be putting a great deal of testing and research into the PI metal detector in the January interim
term as well as the first month of the spring semester to ensure the final product will have the best
implementation of a metal detector that is within our budget. The Surf PI 1.2 pulse induction metal
detector, Figure 27, or the Tiny Pulse Induction Metal Detector, Figure 28, are the likely contenders for
implementation.
Figure 27: Surf PI 1.2 Metal Detector44
36
Figure 28: Tiny PI Metal Detector45
4.8
User Interface
The user interface determines what functionality the user will have and what the user will see visually.
4.8.1
Graphical User Interface (GUI)
A Graphical User Interface will determine what functionality is available to the user and what the design
of information will be. The software used to design the GUI was decided to be Visual Studio, Figure 29.
Figure 29: Visual Studio46
4.8.1.1
Alternatives and Research
There were many factors in deciding how the GUI would look. The design is based on what the user
needs to be able to do and what the user needs to be able see. Various alternatives in design were allowing
the user to log data for later use versus only seeing data as it is collected. Visual Studio also supports a
number of languages and choosing one is a matter of preference.
4.8.1.2. Decision
It was decided that the GUI would be designed in Visual Studio47 using a Windows Application in C#.
This was chosen since Heather has some experience with programming in C# on Visual Studio from the
class CS212, Data Algorithms and Structures and Visual Studio, a Windows supported application. WPF
Applications provide an easy method of designing GUI visually. Visual Studio is powerful and easy to
work with. It also is a commonly used tool and has an extensive supply of tutorials and support. For the
design of the GUI it was decided that the only data logging would be the logging of hits of metallic
objects. All other sensors will be shown on the GUI for the user’s information and will update
continuously. The user will be able to see metal detector hits and corresponding sonar depths, the GPS
location of Amphibot, a steering control panel, webcam feed, and humidity and temperature sensor
results. The humidity and temperature sensor results will display green or red based on safe range for
37
operation. An additional feature that will be created if time allows is to check if Amphibot is about to go
out of range and alert the user.
4.8.2
Mobile Application
A mobile application, Figure 30, will be developed to allow Amphibot to be controlled from a portable
device.
Figure 30: Application Platforms 48
4.8.2.1
Alternatives and Research
Different applications available were researched to determine what platform would be best for Amphibot.
4.8.2.1.1 Android
Android Applications are ideal since they can be created in Visual Studio. Android applications are open
source and have few limitations to getting an application published. Windows device are able to run
Android applications making it available to a wide range of users.
4.8.2.1.2 Apple
Apple applications are closed source and difficult to get published to the store based on strict
requirements from Apple. Apple applications would be beneficial due to the large amount of people who
have iPhones and iPads and would not be able to run Android applications.
4.8.2.1.3 Windows
Windows applications are easy to create thanks to Windows Dev Center which provides step-by-step
instructions to developing and getting applications to the store.49 Windows provides free tools and sample
code that make it easy to create applications. Like Android, Windows is open source.
4.8.2.2
Decision
An Android application was chosen as a platform for a mobile application. This was chosen due to the
large number of people using Android phones and open source nature of Android applications.
4.8.3
Motor Control
The motor controls will be how the user will be able to control the movement of Amphibot. It will need to
interface with the motors and allow for seamless connectivity.
4.8.3.1
Alternatives and Research
The decision of motor control was carefully considered based on what would be ideal and natural for a
user to drive a robot with. The major modes of control were determined to be joystick, keyboard, and
touchscreen commands.
4.8.3.1.1 Joystick
A joystick, see Figure 31, is ideal for Amphibot in that it does not limit the range of movement available
to the user. They are cheap and widely used in driving and gaming purposes. A joystick with buttons
38
would allow the implementation of additional features for the user. The user would be able to manually
mark areas of interest.
Figure 31: Joystick50
4.8.3.1.2 Keyboard
The keyboard control would be a more simple way for users to control the motors. Arrow buttons would
be used to direct the desired movement of Amphibot. The user would be able to use a variety of button
combinations to move Amphibot in the required direction.
4.8.3.1.3 Touchscreen
The touchscreen will be necessary in the cases of mobile devices. The touchscreen will be a graphical
representation of arrow controls.
4.8.3.2
Decision
The final decision was decided to be keyboard arrows for the laptop application and touchscreen with
graphical arrows similar to a keyboard for the Android mobile application. This decision was made based
on limiting the necessary components to drive Amphibot.
39
5
Business Plan
The team developed a business plan for their Amphibot product. This plan focused on marketing the robot
to the specified customer base and on determining appropriate prices for that product based on cost of
parts and labor.
5.1
Marketing
Team 11 is focusing its marketing efforts on the areas where the customer, outdoor hobbyists, are most
likely to shop. Outdoor sporting goods stores like Cabela’s and Bass Pro Shop will sell and market
products from other companies for a commission. This is what the team plans to use to market and
distribute Amphibot.
5.1.1
Competition
In the realm of amphibious robots, most products on the market that serve the same remote controlled
function as a small vehicle with a land and over-water driving are either products in research in colleges
and universities or small toys like remote controlled cars and boats. Products like Aquapod,51 from the
University of Minnesota, make up the bulk of the amphibious robotic industry. Most of these research
robots are designed to explore different modes of transportation. Aquapod moves by tumbling; ACM-R5
moves like a snake in water.52
In the realm of metal detectors, alternatively, competition is mostly from handheld units that require the
user to walk along with the product in order to use it. Some of the more common units of PI metal
detection include the $700 Tesoro Sand Shark,53 the $900 Surfmaster PI Pro,54 and the $2000 Lorenz
LPX2.55
5.1.2
Differentiation
Amphibot will be a versatile robot that can be easily purchased. It will be small and simple to meet
functional needs. It will be low enough in cost to be accessible to a dedicated hobbyist and functional
enough to be of interest to a wide range of amateurs and professionals. It is user-friendly and can be
operated without training by adults and children alike.
5.1.3
Distribution
Because the customer base for Amphibot has as its unifying factor people who enjoy outdoor pastimes
and hobbies and because our company is small and focused, the team chose to distribute its product
through larger outdoors sporting goods stores like Cabela’s and Bass Pro Shop. These larger companies,
with a firm customer base and an established marketing and sales team, would market and sell Amphibot
on a commission and eliminate Amphibot’s need to market itself or hire a sales team of its own.56
5.2
Final Product Cost Estimate
The cost of parts per unit in the final implementation of Amphibot is projected to be $265.5, based on the
breakdown in Table 4.
40
Table 4: Parts' Cost Estimate
Item
Aluminum
Plastic
Rubber
Treadmill Belt Material
Nuts and Bolts
Wheels
Motors
Sonar
Dry Box
Raspberry Pi
Webcam
Metal Detector
Batteries
GPS
Total
Cost [$]
15
4
1
5
0.50
40
30
20
10
35
30
60
15
30
295.5
These cost values were determined by slightly reducing the costs of buying these products individually
under the assumption that they would be bought in bulk for a cheaper cost. The final price of the product
was determined to be $750. This value was determined by considering cost of parts, labor, and other fixed
costs and performing a break-even calculation. This analysis was performed as part of the Engineering
Business class. The break-even analysis is reproduced in Table 5.
41
Table 5: Break Even Analysis
Amphibot
Break - Even Analysis
Year 2
Year 1
Sales revenue
Less: Variable Costs:
Variable Cost of Goods Sold
Variable Operating Costs
Total Variable Costs
Contribution Margin
Less: Fixed Costs
Fixed Cost of Goods Sold
Fixed Operating Costs
Depreciation
Interest Expense
Total Fixed Costs
Income Before Tax
7,500,000
4,000,000
585,000
9,000,000
4,160,000
672,750
4,585,000
2,915,000
670,000
95,000
214,350
262,500
4,326,400
773,663
737,000
95,000
375,924
492,606
Year 2
Year 3
1,241,850 1,700,530 1,621,994
39%
46%
53%
Break Even Sales Volume
3,195,154
3,672,631 3,073,285
Equipment
Purchases
Year 1
Depreciation
Year 2
Year 3
Equipment Purchases Year 1
1,500,000
214,350
367,350
262,350
Equipment Purchases Year 2
60,000
8,574
14,694
Equipment Purchases Year 3
80,000
11,432
214,350
375,924
0.2449
0.1749
7%
Year 1
Year 2
3,750,000 7,037,229
262,500
492,606
Year 3
6,111,686
427,818
0.1429
Interest Expense:
Annual interest rate on debt
Average debt balance
Interest expense
42
5,100,063
5,699,938
810,700
95,000
288,476
427,818
1,700,530
2,466,720
Total Fixed Costs
Contribution Margin %
MACRS Rates (7-year recovery
period)
10,800,000
4,832,750
4,167,250
1,241,850
1,673,150
Year 1
Year 3
288,476
1,621,994
4,077,944
6
Feasibility
With the project defined and the design specified, the team was able to assess ultimate feasibility of
Amphibot as a senior design project. In this section, the team will discuss the feasibility of the project in
terms of team member time, technology and implementation, and will discuss major risks the team is
concerned with.
6.1
Risks
There are a number of steps required for next semester that the team recognizes as potential risks.
Whether because they have a potential to not work at all or to not work together with the other
components, there are still aspects of the project that could cause trouble. Movement, wireless
communication, floatation, and metal detection represent the major risk that, if they fail, will render the
product useless.
6.1.1
Movement
A robot designed to search an area must be able to move. Therefore, making sure that all the components
regarding motion are in place and working properly is an important step in building the prototype.
Because of the many factors that contribute to motion, as well as the complexities involved driving
amphibiously, motion is one area that the team views as a major risk in the future.
6.1.2
Wireless Communication
Being able to move is important, but communicating to the robot to move is necessary if that motion is to
be useful. Making sure that our local area network is working with the Raspberry Pi and with the user,
whether computer-based or smartphone-based, and that the range is wide enough for our requirements is
the next big risk category we envision for the future.
6.1.3
Floatation
The key concern with floatation is ensuring that the robot stays at a level in the water where the treads are
able to propel the robot forward when floating. If the robot sinks, it could be lost and the electrical
components could be ruined. As with other major risks, floatation is a critical component of Amphibot,
without which we would not be able to accomplish our goal.
6.1.4
Metal Detector
The metal detector is by far the riskiest component of Amphibot. Because metal detectors tend towards
either expensive, professional grade, fully constructed devices or small, cheap, inefficient do-it-yourself
kits, finding a metal detector style that can be implemented in the size and cost constraints of Amphibot is
difficult. It needs the sensitivity to pick up small, everyday objects like keys and jewelry and the depth
range to be able to seek more than several inches into the water. The next few weeks for Monica are
going to be dedicated primarily to finding the best options for metal detectors within the price range and
functionality scope requirements. Once an option has been selected, a great deal of testing will go into
making the detector work successfully in the Amphibot system.
In the event that metal detection proves to be unfeasible, side scan sonar is a secondary option to
implement in Amphibot for searching black-water. Side scan sonar is not without its own difficulties, but
the team is confident that between the two technologies they will be able to implement a method of
identifying lost items underwater without the use of visibility.
43
6.2
Time Constraints
The estimated amount of time the team envisions spending next semester in order to satisfy the project
goals by Senior Design Night on May 9 is 675 total labor hours. This time, when broken evenly between
the 3 team members, averages to 17 hours per person per week. This number is feasible, as it represents
the average time expected for a part-time job. The team will have to take care over the course of the
semester that other commitments the team has do not come in the way of the schedule.
44
7
Conclusion
Team Amphibot expects to be able to design and prototype the robot within the financial and physical
constraints. The distance requirement will not be able to be verified until the prototype is made and can be
tested fully assembled. This will depend heavily on the type of batteries used and the quality of the
construction. Other concerns include keeping moisture out of the electronics, foreign objects from
jamming in the body of Amphibot, syncing all of the electrical and mechanical components, and
effectively designing a metal detector with enough sensitivity to be useful but low-powered enough to be
compatible with the other components of the system. The metal detector presents the largest challenge to
the requirements of the design, and as such, it will be a key priority in the coming semester. Future work
involves acquiring, assembling, and testing the electrical and mechanical system, assembling the
prototype, and testing the prototype as an assembled whole.
45
8
Acknowledgements
We would like to thank all those who have contributed to our project. These people include Professor
Mark Michmerhuizen who has taken the role of the team’s primary faculty advisor, Professor Renard
Tubergen who gave the team guidance when it came to interacting with watery environments, Professor
Ned Nielsen who helped the team find an appropriate project that was feasible and challenging, Professor
David Wunder and Professor Jeremy VanAntwerp who are instructors in our senior design class, Ross
Tenney and Tyler DeVries who helped form our business plan, and, finally, Eric Walstra who served as
our industrial consultant. Additional thanks is given to the members of the Calvin Engineering
Department who have all shaped our engineering education.
We would also like to thank those who have supported us throughout our endeavors. The support and
guidance of our families and friends has been invaluable.
46
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47
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41
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42
http://www.whiteselectronics.com/the-hobby/knowledge-base/field-reports/how-metal-detectors-work
43
http://www.adrianandgenese.com/blogger/2012/07/13/how-to-build-a-surf-pi-1-2-pulse-induction-metal-detectorfrom-a-diy-kit/
44
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45
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47
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2
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49
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51
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52
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53
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54
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55
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56
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50
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