Download 7.0 Expected Results Team Lightning Rod expects to have a very

Colorado Space Grant Consortium
GATEWAY TO SPACE
FALL 2010
DESIGN DOCUMENT
Lightning Rod
Written by:
Christopher Bennett, Matthew Dickinson, Jesse Ellison, Matthew Holmes,
Trevor Luke, Sushia Rahimizadeh, Alex Shelanski
October 5th, 2010
Revision A/B
Revision Log
Revision
A/B
Description
Conceptual and Preliminary Design Review
Date
10/5/10
Table of Contents
1.0
2.0
3.0
4.0
5.0
6.0
7.0
Mission Overview……………………………………………………………………….........4
Requirements Flow Down………………………………………………………………........5
Design…………………………………………………………………………………….......6
Management………………………………………………………………………................12
Budget……………………………………………………………………………………….14
Test Plan and Results………………………………………………………………………..14
Expected Results…………………………………………………………………………….15
Gateway to Space ASEN 2500
1.0
Fall 2010
Mission Overview
1.1
Statement
The mission of Team Lightning Rod is to send Zeus, a cubic balloon satellite built from foam
core and equipped with two electromagnetic generators, to an altitude of thirty kilometers and
harness the vibrational and rotational energy experienced during its ascent and descent. A
microcontroller will measure the amount of energy the electromagnetic generators produce. By
analyzing the data collected, team Lightning Rod will determine if future spacecraft will be able
to utilize energy generated by vibrational and rotational motion as additional alternative energy
sources.
1.2
Goal and Background
The goal of this mission is to determine if vibrational and rotational energy can be harnessed as
supplemental energy sources for future spacecraft. If this mission is successful, future spacecraft
will be able to utilize these additional sources of energy, thereby providing their projects with
increased security and protection from complications due to power failure. One of the most
common reasons for spacecraft failure is power loss. Most satellites rely on stored battery power
and solar energy to power their systems. Batteries are not ideal because they do not last
infinitely and can only be recharged when solar panels receive direct sunlight. Solar panels limit
the spacecraft because they must be large enough to provide energy. Thus, solar panels add a
heavy weight restriction to the spacecraft. Also, solar panels are fragile and break easily when
the satellite encounters debris or atmospheric turbulence. Solar panels are particularly
vulnerable when the rectangular body of the solar panel extends out from the satellite and is
narrowly attached to the structure. Because satellites are limited in their ability to power
systems, energy supply is the satellites most important system. If power fails, all other systems
fail. Thus, additional sources of power are greatly needed. The energy harnessed from
vibrations and rotations is not expected to be enough to fully power all satellite systems.
Nonetheless, it would prolong the life of a satellite and prevent mission failure.
The idea of generating power from vibrations was researched by students at the University of
Southampton in England. The students developed a micro scale vibrational generator that was
capable of powering wireless sensors. Although the design was only experimented on an air
compressor, they stated in a journal that was submitted to the Journal of Micromechanics and
Microengineering that they believe similar and suitable vibrations could be found in airplanes as
well. In a book called Energy Harvesting Technologies by Shashank Priya and D. J. Inman, it
was also discussed that there is an observed increase in power generation as generators increase
in size. Considering that the generator developed by team Lighting Rod will be subjected to an
environment comparable to airplanes and that its design is larger than the design developed at the
University of Southampton, and thus more efficient, team Lightning Rod anticipates that the
vibrational generator they develop will produce more power.
By testing two generators that harvest the energy from rotational and vibrational motion, team
Lightning Rod will analyze the efficiency of the designs and determine if either design could be
used to generate energy for future spacecraft. Research can be found on similar instruments that
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Gateway to Space ASEN 2500
Fall 2010
were developed for the purpose of non-aerospace applications, which will serve as the basis for
the initial developments for the rotational generator. Students at the Imperial College in London
also developed an energy harvester for powering wireless sensors using the rotations of the
harvester's environment to create a dynamic magnetic field. As they stated in a paper titled
Wireless Sensor Node Using a Rotational Energy Harvester with Adaptive Power Conversion,
they sought a compliment to vibrational energy harvesting technology in order to maximize the
potential of a given mechanical system's ability to gather energy. Their design consists of a mass
atop a rotational disk that is offset from the center. Team Lightning Rod chose to arrange their
magnets uniformly on the outer edges of the disc for the purpose of maintaining higher rotational
speeds.
2.0
Requirements Flow Down
The requirements flow down is designed to portray how the requirements relate to the objectives
and the goal. The goal is derived from the mission statement. Then, the level 0 requirements are
the mission objectives. The mission objectives are derived exactly from the goal and mission
requirements presented by Space Grant. Finally, each objective has several requirements
underneath it that explain how it will accomplish the objective. The requirements are considered
level 1 requirements on the flow chart. In the chart, the name of the objective or requirement is
in the left column, the middle column has the specific objective or requirement, and the far right
column shows where that specific goal or requirement is referenced.
The goal of team Lightning Rod is to send a balloon satellite equipped with two electromagnetic
generators to an altitude of thirty kilometers to determine if the kinetic energy from vibrational
and rotational motion can be harnessed as supplemental energy source for future spacecraft.
Objective
O1
O2
O3
O4
O5
O6
O7
Mission Objectives Level 0
Fly a satellite to 30 km
Keep the internal temperature of the satellite above -10 degrees Celsius
Keep the overall weight of the satellite below 850 g
Fly a Cannon Camera and the HOBO datalogger on the satellite
Capture and store vibrational energy using the vibrating electromagnetic generator
Capture and store rotational energy using the rotating electromagnetic generator
Compare the results of the rotational generator and the vibrational generator to see
which one is most effective
Reference
Goal (G)
Goal (G)
Goal (G)
Goal (G)
Goal (G)
Goal (G)
Goal (G)
Requirements
O1.R1
Objective 1 Requirements Level 1
Satellite Zeus will be attached to a helium weather balloon that will carry it up to
30 km.
Satellite Zeus will be attached to the balloon on a piece of rope that will run
directly through the center of the satellite.
Satellite Zeus will be kept stable on the rope by using washers and clips.
Reference
O1
Objective 2 Requirements Level 1
Satellite Zeus will be kept above -10 degrees by using an electric heater that will
be created by Team Lightning Rod and will be powered using 9V batteries.
Satellite Zeus will have ½ inch foam insulation to keep the Satellite above -10
degrees Celsius
Satellite Zeus will also have no holes to contain the heat in the satellite.
Reference
O2
O1.R2
O1.R3
Requirements
O2.R1
O2.R2
O2.R3
Team Lightning Rod
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O1
O1
O2
O2
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Fall 2010
Requirements
O3.R1
Objective 3 Requirements Level 1
Satellite Zeus will be less than 850 grams by keeping a very meticulous budget
that keeps track of the weight of every piece of equipment that will be on the
satellite.
Reference
O3
Requirements
O4.R1
O4.R2
Objective 4 Requirements Level 1
Satellite Zeus will fly the Cannon camera to capture photos of near space.
The camera on Satellite Zeus will be programmed ahead of time so that it will
work independently of all other electronics during the flight.
The HOBO datalogger will be a standalone item in the satellite that will measure
the internal temperature, external temperature, and relative pressure.
The HOBO datalogger information will then be used to determine the satellites
position at certain times during the ascent and descent of the satellite.
Reference
O4
O4
Objective 5 Requirements Level 1
The electromagnetic generator will have magnets that vibrate across a copper coil
as the satellite vibrates, thus producing an electric current.
The created energy will then be held in a capacitor.
The amount of energy in the capacitor will be constantly measured and recorded
by the data storage device on the microcontroller.
Reference
O5
Objective 6 Requirements Level 1
The electromagnetic generator will have magnets that rotate across copper coils
as the satellite rotates around the flight string, thus producing an electric current.
The created energy will be held in a capacitor.
The amount of energy in the capacitor will be constantly measured and recorded
by the data storage device on the microcontroller.
Reference
O6
Objective 7 Requirements Level 1
After Satellite Zeus is retrieved, the data from the two generators will be uploaded
onto a computer for analysis.
The data results will be documented as a function of time and also in reference to
the information retrieved by the HOBO datalogger so that the best results at the
relative moments of the flight will be known.
Reference
O7
O4.R3
O4.R4
Requirements
O5.R1
O5.R2
O5.R3
Requirements
O6.R1
O6.R2
O6.R3
Requirements
O7.R1
O7.R2
3.0
O4
O4
O5
O5
O6
O6
O7
Design
3.1
Concept
Utilizing principles defined by modern electromagnetic theory, two generators on-board Zeus
will produce electricity derived from the mechanical oscillations of eight neodymium magnets
near a fixed copper coil per generator. The vibrations will move the magnets, inducing a
magnetic flux across the copper coil, as described by Faraday's Law. The magnetic flux across
the copper coil will drive a current. The force on the charges from the magnetic field will oppose
the change in magnetic flux and drive the current in the coil, according to Lenz's law.
Zeus will feature two electromagnetic generators. One will harness the vibrational energy, the
other with capture the rotational energy. Each will be connected to a separate electrical load that
will be monitored by a microcontroller. The load seen by the generators will be in the form of a
capacitor bank. The bank will have a limited capacity, thus will be monitored and emptied when
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Fall 2010
filled. Each time the bank is emptied the micro-controller will register the dump. This data will
be used to calculate the total energy created. There are four components that will be considered
in the model design of the vibrational generator: a magnetic field, a coil, a vibrating mechanism,
and an electric circuit (or load). A coil made of copper will be set fixed to the frame of the
spacecraft and inside a set of randomly oscillating magnets. There will be two sets of magnets,
four square neodymium magnets of alternating polarity for each set, each placed near one side of
the copper coil. The vibrating mechanism, in the form of spring metal, will support the
bidirectional movement of the magnets, which together will create a magnetic flux when
experiencing an acceleration of force. The ends of the coil will be connected to a circuit capable
of accumulating the power generated, as well as manipulating the current as desired to support
the objectives of the experiment. Rubber stoppers will be placed on the generator structure to
limit the magnets oscillation by contact between rubber and magnet, thereby preventing damage
to the magnets and structure. The rotational generator will use the same electric laws, but will
have a different method of creating the moving magnetic flux. There will be eight copper coils a
ranged in a circular pattern fixed to the body of the satellite. Above the coils there will be a free
spinning disk with a pattern of magnets in the same configuration as the coils along the edge.
The disk with spin with a semi-random motion in relation to the fixed coils creating the moving
flux that then drives a current in the coils. The coils will be connected in parallel and then to a
electrical load identical to that used by the vibrational generator.
For the duration of the flight, energy will be harvested from the local environment via the
generators and stored into a custom designed capacitor bank. Diodes will be used to regulate the
direction of a dynamic current flow produced by the generator. A rectifier will be implemented
in order to ensure a single output polarity, as well as a direct current instead of an alternating
current. A full-wave bridge rectifier is preferred, as it will is more efficient than a half-wave
rectifier. The rectifier is to be designed with 4 diodes arranged in a “diode bridge” configuration
that will feed the load. The load will be a single capacitor bank for each generator. A capacitor
bank will be constructed by connecting ten tantalum capacitors is parallel. This construction
technique is known as multi miniature capacitor bank, or MMC bank. A MMC bank was chosen
partly because of the robustness of tantalum capacitor. Due to the fact that the MMC will be
subject to low pressure and extreme temperature, it must be built to withstand a large amount of
abuse. The other factor that determined the construction technique was the low capacitance of
tantalums for their cost. Many small capacitors in parallel are much more cost effective when
compared to a single high capacitance tantalum capacitor. To solve the issue of the generators
possibly over charging the MMC and damaging it, the voltage will be constantly monitored.
When it reaches a set point, the bank will be shorted and the energy stored will be dumped.
When this occurs, the microcontroller will make note within the data timeline. A relay will be
used to short out the MMC and dump the energy.
The data associated with the generator will be continuously recorded for the duration of the flight
and stored on a separate data storage device. The information that will be stored onto the microcontroller will include the data from all of the sensors accept for temperature and humidity.
Team Lightning Rod will analyze the temperature and humidity data using the HOBO’s
“Boxcar” program and analyze the generator data using Mathematica. The team will also match
data from both the HOBO and Microcontroller Data Storage on a single timeline and determine
any existing correlations.
Team Lightning Rod
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3.2
Fall 2010
Plan
Team Lightning Rod ordered many of its necessary hardware components including magnets
from Magnet4less.com, spring steel from McMaster.com, a microcontroller and a development
board from SparkFun, and capacitors, relays, and switches, an LDO regulator, and a data storage
device from mouser.com. Provided hardware from Space Grant and The ITLL consisted of
aluminum tape, anti-abrasion washers, Canon camera, foam core sheets, heater, HOBO, hot glue,
and plexi-glass. Items that still need to be purchased include: nine volt batteries, double A
batteries, 30 gauge copper wire, machine screws, and rubber bumpers. Now that plexi-glass has
been attained, Team Lightning Rod will cut the plexi-glass and form the basic structure of the
two generators. After creating the structures of the generators, the plexi-glass will be attached to
the machined spring steel using machine screws. The magnets will then be attached on the end
of the spring steel, and the copper wire will be placed between the magnets. This will be the
vibration generator for Zeus. Similarly to the vibration generator, plexi-glass for the rotational
generator will be cut and magnets will be fixed into their respective locations. A bearing will
insure that the generator is free to turn and will connect the two circles of plexi-glass housing
magnets together. The generators will then need to be tested to make sure that the conceptual
design works, and necessary alterations will be made to create as efficient of a generator as
possible. The next system that will be created will be the structure of Zeus. To begin
constructing the structure, Team Lightning Rod will cut foam core into the 2-dimensional cube
pattern. Then, the 2-dimensional cube pattern will be transformed into a 3-dimensional cube.
The holes for the string attachment will be cut and the string attachment will be added to the
cube through two washers, a tube, and the paper clips. Testing of the cube’s durability will
ensue with the Whip Test, Drop Test, and Kick Test. Once the structure is known to have a
durable design, Team Lightning Rod will assemble all electronics according to the functional
block diagram. Finally, the constructed project will be tested with a Cold Test and a vibration
test to make sure that everything is insulated and working properly. The Team will then make
necessary changes, place contact information and an American flag on Zeus, and then launch it.
3.3
Diagrams and Drawings
Team Lightning Rod
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Fall 2010
Rotational Generator
Team Lightning Rod
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Fall 2010
Vibrational Generator
3D Isometric View
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Fall 2010
Unfolded View
2D Unfolded with Dimensions
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4.0
Fall 2010
Management
Team Lightning Rod will be managed by Trevor Luke. Each member holds a vital role in the
project and all members will contribute to construction and finalization of the satellite Zeus and
its components. Each team member is assigned a formal role and assistant duties to ensure that
not only one person is working on each aspect of the satellite. Finalization of Zeus is estimated
to occur two weeks before launch. All of the roles of team members are detailed in the charts
given below:
4.1
Organizational Chart
NAME
JESSE ELLISON
MATT HOLMES
TITLE
ELECTRONICS HEAD
BUDGET HEAD
MATHEW
STRUCTURE CO-HEAD
DICKINSON
CHRIS BENNETT STRUCTURE CO-HEAD
TREVOR LUKE
TEAM LEADER
ALEX LOUIS
SUSHIANS
RAHIMIZADEH
ALL
4.2
ADDITIONAL RESPONSIBILITIES
DRAFTING/DESIGN
PROGRAMMING ASSISTANT/
DOCUMENTATION
TESTING ASSISTANT
PRESENTATION COLLABORATOR
TEAM SCHEDULING/
COMMUNICATIONS/
DOCUMENTATION
TESTING HEAD
FILM
PROGRAMMING HEAD MISSION DESIGN
ALL TEAM MEMBERS WILL ASSIST IN EVERY ASPECT OF THE
PROJECT.
Flow Chart
Team Lightning Rod
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4.3
Fall 2010
Schedule
Complete proposal and presentation and submit online—Due 9/16 by 7:00 am
Fill out order form and order hardware—9/23 at 11:30
Team meeting-10/4 at 3:00
Cut out generator structures-10/4
Wrap copper coils-10/4
Write presentation-Due 10/5 by 7:00
Team meeting-10/5 at 3:00 pm
Test structure—10/5 to 10/8
Assemble magnets and spring steel for vibrational generator-10/5
Complete construction of vibrational and rotational generators—10/8
Team meeting-10/10 at 2:00 pm
Test and adjust generator design to optimize voltage-10/10
Assemble and wire satellite—10/10 to 10/15
Complete the wiring of satellite—10/16
Team meeting-10/17 at 2:00 pm
Program satellite hardware—10/17 to 10/22
Final Construction Completed—10/23
Team meeting-10/24 at 2:00pm
Final Testing—10/24 to 10/29
Project Finished—10/30
Buffer Week—10/31 to 11/5
Finish Critical Design Review-11/2
Launch—11/6
Write final presentation-11/30
Finish Analysis and Final Report- 12/4
Team video due-12/4
Team Lightning Rod
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5.0
Budget
6.0
Test Plan and Results
Fall 2010
Prior to the flight, team Lightning Rod will test the payload to make sure that it will convert the
kinetic energy from the vibrational and rotational motion to electrical energy. These tests will
consist of shaking the generators and simulating the real life events the satellite will experience
on its flight. The generators will be attached to an oscilloscope, which will determine if the
generator will produce a significant amount of energy from motion. After the team determines
that the generators will work, Team Lightning Rod will test the integrity of the satellite and its
ability to withstand extreme temperatures and collisions. For the cold temperature testing, the
team will place the balloon satellite and the payload into a cooler of dry ice and let it sit there
until it reaches a temperature of -80 degrees Celsius, which to what it is expected to be at an
altitude of 30 km. The dry ice will be handled with gloves and tongs, and will be contained in a
Team Lightning Rod
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styro-foam chest with a loosely fit lid. To test its ability to withstand collision, the test team will
subject the prototype structure to a battery of tests that will simulate its descent after the balloon
pops. For these tests, the team will fill the balloon satellite structure with rocks to replicate the
weight of the actual satellite. The test team will do a whip test, in which the team will attach the
prototype to a string, similar to the one used on launch day, and swing it around in circles. This
will test both the ability of the structure to endure the whipping motion after burst as well as the
structures ability to maintain a good hold onto the flight rope. The team will make sure that the
swinging will be directed away from any person and in a secluded environment. In performing
this test, the team will vary the length of the string to determine the satellite’s ability to grip the
string as acceleration changes. The test team will perform a series of drop tests. In these tests, the
team will drop the structure from varying heights to determine if the satellite will withstand the
ground collision on landing. The test team will also conduct a series of drop tests with the
satellite payload included to examine the affects of violent forces on the generators. From these
tests, the team will analyze the structural weaknesses of the satellite and fix them before launch
day. The testing team will also test the camera to make sure that the timing chip is operating
properly. The first test will be at room temperature. The team will place the camera on a table
and turn on the timing chip to make sure that it works without additional parameters. Then the
team will also test the camera’s ability to take pictures in a cold environment. The team will
place the camera in a cooler of dry ice to simulate the temperatures experienced at 30 km above
sea level, minding the safety precautions that may accompany the handling of dry ice. After
testing the structural integrity of Zeus, the electronics and programming heads will conduct a
series of functional tests. These tests will evaluate the payload’s ability to operate as an
integrated system. The first of the functional tests will be done under stable electrical conditions
to see if the system can operate for 120 minutes, which is 30% longer than expected flight time.
Then the system will be tested under low and high voltage conditions. Each test that involves the
payload in any way will be subject to a test of the data retrieval abilities of the system. The
structure team will collect the data from these tests and analyze it to determine necessary
adjustments in the structures design.
7.0
Expected Results
Team Lightning Rod expects to have a very large amount of data to interpret results from. First,
it is expected that the vibrational generator will generate a measurable amount of power. The
data acquired will be matched to that of an external accelerometer to verify the power generated.
We expect similar results from the rotational generator but possibly more power harvested. The
voltages on the capacitor banks for each of the generators will be measured by the
microcontroller every second. Team Lightning Rod expects that there will be an increase in the
power generated when the balloon passes through the more turbulent parts of the atmosphere.
The vibrational generator will generate a peak amount of power just after burst, it is expected.
The performance of the generators should be semi impervious to environmental factors. One
possible effect would be that of the temperature. There might be a slight power increase when
the temperature is at its' lowest due to a decrease in the resistance of the copper wire in the coils
and thus less energy lost to heat.
Team Lightning Rod
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