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Slide 1
Colorado State University Paul Scholz, Tyler Faucett, Abby
Wilbourn, Michael Somers June 14 2010 1
Slide 2
Mission Overview Objective: to study alternative energy
collection at different altitudes Find the ideal altitude for
alternative (wind & solar) energy collection. Is high altitude
energy collection worthwhile? Can the added cost of high altitude
energy collection be made up for with increases in efficiency?
2
Slide 3
Current Products MARS Maggen Air Rotor System 3
Slide 4
CoolEarth Solar Balloon MARS turbine 4
Slide 5
How we can help Our test could provide useful data to someone
wishing to put up a similar system on Earth or Mars An airborne
solar/wind power farm could be very useful for remote area power
generation Our test vehicle will provide data to give an altitude
of maximum power generation. 5
Slide 6
Mission Requirements 6 REQUIREMENTMETH ODSTATUS Payload mass
must be 1.5 kg or lessDesign and use of lightweight materials
Payload must accommodate flight string per the users guide Design
and test Payload must pass all structural tests in users guide
Design and test Payload must successfully complete all functional
and environmental tests Design and test Payload must have the
capability to complete all mission objectives Design and test
Payload must cost under $1000Budget carefully
Slide 7
Concept of Operations Just before launch power to the heaters
and microcontroller will be turned on via switches on the top of
the payload The microcontroller will run its program which includes
taking input from 5 different sources and transmit the data
serially back to the SD card at a rate which we will specify for
each sensor After the program has run for 150 minutes, the program
will end so that we do not write over our flight information with
data collected on the ground 7
Slide 8
Subsystems Structural Thermal Data Storage Processing
Electrical Sensing 8
Slide 9
Subsystem Structural Must have cylindrical shape Allows for
even and constant sun exposure to solar faces Must have center core
flight string pass through Pass through design must comply with all
DemoSAT-B regulations Pressure differences inside and outside the
payload must not exceed 10 psid 9
Slide 10
Subsystem - Thermal The internals of the payload must remain
above 0C to prevent failures of electrical components The internal
electrical components must be placed as close to the center of the
payload as possible Internal flexible heaters will be installed to
maintain required internal temps. Flexible heaters allow for easy
placement near critical components (battery) Temp. Distribution
Flux 10
Slide 11
Subsystem - Data Processing All sensor data shall be processed
on a PIC 16F884 microcontroller Storage The PIC shall send data
from the sensors to the data storage unit every 5 seconds The data
storage device shall be removable and portable and must allow for
computer interface 11
Slide 12
Subsystem - Electrical All electrical components must be
powered by a 5V source The power supply must be able to produce
4.8V to 6V for at least 2 hours Switches for electrical components
must be mounted on the external of the payload 12
Slide 13
Subsystem Sensing Wind Speed Sensing Anemometer must be at
least 2in from the flight cord At least 2 axis of acceleration must
be sensed to accurately measure wind speed Altitude Sensing Payload
must contain at least 1 pressure sensor and 1 temperature sensor
Pressure and Temp must be measured externally for accurate data
Solar Panels Solar panels must cover at least 90% of the rounded
faces of the payload All external sensors must be able to operate
at temperatures ranging from -80C to 30C 13
Commands and Sensors Sample Rate Sample Duration # of samples
Bytes/ Sample (estimated) Min Required Memory For data storage
Available Memory 1 sample every 5 seconds 2 hours 1440 (samples/
sensor) * 6(sensors) = 8640 samples 4 bytes34560 bytes2Gb SD (less
due to formatting, etc.) Data transferred serially from PIC
microcontroller to SD card mounted in SD card reader. 22
Slide 23
23
Slide 24
Sensor Specifications SensorOperational Voltage Operational
Temperature Measurement Range Notes Temperature3.0 to 5.5V-55C to
+125C Converts Temperature to 12-bit Digital Word in 750 ms
Pressure5.0V0C to 85C0 psi to 1 psi through 0 psi to 100 psi
Response time of 8 ms Accelerometer (2-axis) 2.4V to 5.25V-20C to
70C+/- 18g----- Cup Anemometer ----- 3 mph to 125+ mph 2.5 mph per
Hz (1 Hz=1 pulse/sec) Solar Panels (3) ----- Voltage: 7.2 V Watts:
1.44 W Amperage: 200 mA 24
Slide 25
Accelerometer Math 25 X and Y out were generated randomly
Samples were taken every second for this example
Slide 26
Test Plans Testing Types Structural Test Whip test Drop test
Stair pitch test Environmental Test Cooler Test Functional Tests
Bench Test 26
Slide 27
Structural Tests Test Structure Made in the same fashion as
actual structure with minor differences Heavier outer shell with no
carbon fiber around the foam Thicker (2x) mounting plate Ballast
taped to mounting plate on inside Accelerometer bracket attached
Aluminum square screwed to top to simulate the anemometer. Total
weight was 3.25 lbs 27
Slide 28
Test Structure Photos 28 Assembled test structure Pieces of
ballast usedRemovable Frame
Slide 29
Whip Test Performed 5 whip tests and took video of all of them.
Payload was spun overhead as fast as possible After being at speed
for several revolutions the experimenter pulled in on the string as
hard as possible to simulate a high g-load. The length of rope from
the hand of the experimenter to the payload cg was 80 inches From
the video the calculated angular velocity was 60 RPM The calculated
g load at these conditions was 8.2g with the peak during the pull
being higher 29
Slide 30
Potenial Damage/Assessment Top plate could have been bent Epoxy
interface between the tube and fitting could fail Acrylic posts
imbedded in the foam could pull out or break No damage was observed
during this test 30
Slide 31
Whip Test Video 31
Slide 32
Stair Pitch Test Structure was kicked down a flight of 13
concrete steps Step profile was 7.25 inches tall and 10.5 inches
long 32
Slide 33
Potential Damage/ Assessment CF tube could break Foam could
fracture Acrylic posts breaking or pulling out Top plate bending
One Acrylic post was broken during the tumble at the base of the
nut All other parts were unharmed Possible fix would be to shorten
the posts to be only as tall as the nuts to lessen the moment on
impact 33
Slide 34
Drop Test Structure was thrown off a balcony from a height of
22.63 ft. above the concrete ground It landed almost sideways but
angled enough that the top plate took the initial impact 34
Slide 35
Potential Damage/ Assessment Broken CF tube Acrylic posts
breaking or pulling out Foam breakage Top plate bending The top
plate was bent from impact The foam fractured and broke from impact
The foam layers separated near the region of impact The fix for the
foam is that it will be encased in a carbon fiber outer shell
35
Slide 36
Structural Test Summary No repairs were made during testing
Weak points were discovered to be the acrylic posts and the top
aluminum plate Of the five pieces of ballast originally taped to
the mounting plate before the tests 3 were still attached The plate
may have bent less from the drop test if the third post had still
been there From the tests we are confident that the electronics on
our payload will survive the extreme conditions they may encounter
and our data will be recoverable 36
Slide 37
Secondary Whip Test This test was added after the other tests
had been completed and analyzed In this version of the whip test,
we dropped the payload attached to a 10 foot rope The sudden stop
the payload experienced as the rope came to its full length was a
better way to impart a sudden directional change in order to
determine if the posts would hold, and if the internal electronics
would stay secure All other tests had been performed previously,
and the damage was repaired 37
Slide 38
Potential Damage/Assessment The post that previously broke and
was re-glued broke again Minor foam fractures around the posts No
internal ballast pieces separated from the mounting plate Overall,
there was no significant additional damage to the structure. We are
still confident that the top plate will remain secure, as well as
the internal electronics Vibration testing may be analyzed when all
electronics are in place to verify that our data will be
retrievable 38
Slide 39
Secondary Whip Test Video 39
Slide 40
Environmental Tests Cooler Test Must purchase Dry Ice and
Cooler Potential Point of Failure: Payload: Insulation design may
be flawed and low internal temps may cause freezing/condensation on
electrical components. Adjustments may need to be made to heater
placement and insulation 40
Slide 41
Solar Panel Cold Test The solar panel output will be tested for
variations in temperature The panel, a 90 W light source above the
panel, and a thermocouple will be placed inside a refrigerator
originally at room temperature The refrigerator will then be turned
on to its highest setting The solar panel output and temperature
will be recorded at a constant temperature interval of 2 degrees
Celsius 41
Slide 42
Setup 42
Slide 43
Results The starting temperature was 22 C Final temperature was
-18 C Voltage readings were taken with a multimeter every two
degrees The voltage readings combined with known resistance values
yielded current and power Dry ice was added to the refrigerator to
reach the lowest temperature 43
Slide 44
Temperature Relationships 44
Slide 45
Functional Test Bench Test Potential Points of Failure:
Overheating of internal electrical components No data transmission
to SD Card No data transmission from sensors Wiring failure 45