Transcript spacegrant.colorado.edu

Preliminary Design Review
PDR Presentation Contents
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Section 1: Mission Overview
• Mission Statement
• Mission Requirements
• Mission Overview
• Theory and Concepts
• Literature Review
• Concept of Operations
• Expected Results
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PDR Presentation Contents
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Section 2: System Overview
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Physical Model
Critical Interfaces
Requirement Verification
User Guide Compliance
• Section 3: Subsystem Design
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Energy Harvesting Subsystem
Structural Subsystem
Electrical Subsystem
Visual Verification Subsystem
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PDR Presentation Contents
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Section 4: Prototyping Plan
• Projected Prototyping Process
• Prototype Risk Assessment
• Section 5: Project Management Plan
• Organizational Chart
• Schedule
• Budget
• Work Breakdown Schedule
• Sharing Logistics
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Drexel RockSat Team 2011-2012
Mission Statement
Develop and test a system that will use
piezoelectric materials to convert mechanical
vibrational energy into electrical energy to
trickle charge on-board power systems.
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Mission Requirements
Number
Requirement
MIS-REQ-1000 Must be able to convert vibrational energy to electrical energy
MIS-REQ-2000 Must be able to withstand launch environments
MIS-REQ-3000 Final design must meet RockSAT specifications
MIS-REQ-4000 Must be functional during flight
MIS-REQ-5000 Must not interfere with canister partner’s design
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Mission Overview
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Demonstrate feasibility of power generation via
piezoelectric effect under Terrier-Orion flight
conditions
Determine optimal piezoelectric material for
energy conversion in this application
Classify relationships between orientation of
piezoelectric actuators and output voltage
Data will benefit future RockSAT and CubeSAT
missions as a potential source of power
Data will be used for feasibility study
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Theory and Concepts
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Piezoelectric Material
substance with linear electromechanical
interaction between mechanical and electrical
states in crystalline materials
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Piezoelectric Effect
electrical potential (voltage) developed within
a piezoelectric material in response to an
applied pressure or stress.
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Theory and Concepts continued
Where D is electric displacement, ε is permittivity,
and E is electric field strength
Where S is mechanical strain, s is compliance,
and T is mechanical stress
Superscript e denotes a zero/constant electric field;
Superscript t denotes a zero/constant stress field;
d indicates piezoelectric constants
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Theory and Concepts continued
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Array of piezoelectric actuators
• Bonded to
cantilevered
aluminum strips with
mass attached to
free end
• Dynamic deflection
under vibration and
g-loading will create
voltage potential
• Various orientations will account for vibrations in
multiple directions
http://en.wikipedia.org/wiki/EulerBernoulli_beam_equation
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Theory and Concepts continued
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Place mass at end of beam
to achieve maximum
deflection under vibration
Model with point load
Top: Bending Moment, M(x)
Middle: Shear Force, Q(x)
Bottom: Deflection, δ(x)
http://en.wikipedia.org/wiki/EulerBernoulli_beam_equation
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Theory and Concepts continued
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Uniform, distributed load
when subjected to g-forces
during launch
Model with load acting
along length of beam
Top: Bending Moment, M(x)
Middle: Shear Force, Q(x)
Bottom: Deflection, δ(x)
http://en.wikipedia.org/wiki/EulerBernoulli_beam_equation
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Theory and Concepts continued
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Electric potential
(voltage) developed
throughout piezoelectric
actuators in AC form
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AC voltage conditioned
using a full-bridge rectifier
Accumulated in a
capacitor
Monitored using a
voltmeter
Recorded using data
acquisition system (DAQ)
http://en.wikipedia.org/wiki/Diode_bridge
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Literature Review
Piezoelectric Generator Harvesting Bike
Vibrations Energy to Supply Portable Devices
E. Minazara, D. Vasic, and F. Costa
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Piezoelectric generator that
harvests mechanical vibration
energy and produces electricity
Determined optimal band to harvest energy 12.5Hz
Modeled piezoelectric beam as spring mass
damper system
Produced ~3.5mW electricity
capable of powering LED
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Literature Review continued
Recent Progress in Piezoelectric Conversion and Energy
Harvesting Using Nonlinear Electronic Interfaces and Issues in
Small Scale Implementation
D. Guyomar and M. Lallart
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Design of an efficient microgenerator must consider:
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Maximization of input energy
Maximization of electromechanical energy
Optimization of energy transfer
Increase conversion abilities by:
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Increase voltage
Reduce time shift between speed and voltage
Increase coupling term
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Literature Review continued
A Review of Power Harvesting Using Piezoelectric Materials
S. R. Anton and H. A. Sodano
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PZT widely used
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PVDF exhibits considerable flexibility
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Extremely brittle
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Piezoceramics prone to fatigue crack growth when
subjected to high-frequency cyclic loading
Flexible materials more beneficial
Practical coupling modes
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-31: Force applied perpendicular to poling direction
-33: Force applied in same direction as poling
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Literature Review continued
A Review of Power Harvesting Using Piezoelectric Materials
S. R. Anton and H. A. Sodano
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High power output situations
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Stack configurations most durable in high-force
environments
When driving frequency is at resonant frequency of the
system
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Literature Review continued
Comparison of Piezoelectric Energy Harvesting Devices for
Recharging Batteries
H. A. Sodano and D. J. Inman
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Researchers tested energy-harvesting qualities of three
different piezoelectric materials
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Lead-zirconate-titanate (PZT)
Quick Pack bimorph actuator material (QP)
Macro Fiber Composite (MFC)
Measured vibration of compressor, using piezo samples
as accelerometers – output in volts
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Full-bridge rectifiers used to condition signal from
oscillating AC into DC to charge batteries
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Literature Review continued
Comparison of Piezoelectric Energy Harvesting Devices for
Recharging Batteries
H. A. Sodano and D. J. Inman
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Efficiencies varied by material
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QP most effective for resonant frequencies (~8 to 9%)
PZT most effective for random vibrations (~4 to 4.5%)
MFC significantly less effective than PZT and QP
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Low-current, high-voltage output lacks the strength to
charge batteries and is easily dissipated by diodes in circuit
QP charged batteries fastest under resonant
frequencies; PZT charged the best with random
vibration.
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Literature Review continued
Piezoelectric Sea Power Generator
R. M. Dickson
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Operating principle
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Attempted to harness mechanical energy of waves as
changes in pressure acting upon piezoelectric mats
Minimally intrusive to ecosystem
Important implications for this project
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Studies show that static pressure alone does not induce a
charge in piezoelectric materials
Piezo arrays must be continuously deformed to create an
electric potential that can be harvested
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Concept of Operations
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G-switch will trip upon launch, activating all
onboard power systems
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Batteries power Arduino microprocessor and data
storage unit
Data collection begins
Vibration and g-loads on piezo arrays create
electric potential registered on voltmeter
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Current conditioned to DC through full-bridge
rectifier and run to voltmeter
Voltmeter output recorded to internal memory
Data gathered throughout duration of flight
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Concept of Operations
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Data acquisition and storage will enable
researchers to monitor input from multiple sources
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XY-plane vibrational energy
Z-axis vibrational energy
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Researchers will determine if amount of power
generated is sufficient for the power demands of
other satellites
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Include visual verification of functionality
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Use energy from piezo arrays to power small LED
Onboard digital camera will verify LED illumination
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Expected Results
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Piezoelectric beam array will harness enough
vibrational energy to generate and store
voltage sufficient to power satellite systems
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Success dependent on following factors:
Permittivity of piezoelectric material
• Mechanical stress, which is related to the
amplitude of vibrations
• Frequency of vibrations
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Christopher Elko
Physical Model
Microcontroller
Power
Supply
Camera
Accelerometers
Piezo
Arrays
Verification
LED
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Subsystem Identification
EPS – Electrical Power Subsystem
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Includes Arduino microprocessor, g-switch,
accelerometers, voltmeter, battery power supply,
and all related wiring
STR – Structural Subsystem
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Includes Rocksat-C decks and support columns
PEA – Piezoelectric Array Subsystem
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Includes piezoelectric bimorph actuators, cantilever
strips, mounting system, rectifier, and related wiring
VVS – Visual Verification Subsystem
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Includes digital camera, LED, and all related wiring
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Critical Interfaces
Interface Name
Brief Description
Potential Solution
EPS-STR
The electrical power system boards will need to mount to the
RockSat-C deck to fix them rigidly to the launch vehicle. The
connection should be sufficient to survive 20Gs in the thrust axis
and 10 Gs in the lateral axes. Buckling is a key failure mode.
Past experiences show that stainless steel or
aluminum stand-offs work well. Sizes and
numbers required will be determined by CDR.
STR-PEA
The piezoelectric bimorph actuators must integrate into the
structure without introducing a hazard to the operations of other
satellite operation. The structure must also be designed such that
the oscillatory motions of the piezo array cantilevers will not be
impeded. Fracture is a key failure mode.
Testing will verify mounting methods and
loading limitations of piezo actuators. Testing
will also determine ideal range of deformation
for maximum power generation.
PEA-EPS
The piezoelectric actuators must be wired correctly to ensure a
voltage signal reaches the voltmeter and is registered by the
DAQ.
AC signal may need to be conditioned to DC with
a rectifier and amassed using an inline capacitor.
Testing will verify whether parallel or series
wiring should be used.
VVS-STR
The components (camera, LED) of the visual verification system
must be mounted to the RockSat-C deck to fix them rigidly to the
launch vehicle. The connection should be sufficient to survive
20Gs in the thrust axis and 10 Gs in the lateral axes.
Utilize stainless steel or aluminum standoffs, as
in EPS-STR interface above.
VVS-PEA
The LED component of the visual verification system must
illuminate when a voltage is generated by the piezo arrays.
Wire LED in series with PEA to ensure proper
illumination.
EPS-VVS
The camera component of the visual verification system must be
powered from a steady, reliable source. Camera data must also
be stored for playback after the flight.
Power camera from same battery source as
microprocessor.
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Requirement Verification
Requirement
Description
Verification Method
The full system shall fit in the allotted
space within the canister.
Visual inspection will verify this requirement.
The system shall survive the vibration
characteristics prescribed by the
RockSAT-C program.
The system will be subjected to these vibration
loads during preliminary testing on an associated
institution’s vibration table, as well as in June
during testing week.
The power supply shall be engaged via
the g-switch and all electronic systems
powered on upon launch.
The minimum load needed to activate the g-switch
and engage electronic systems will be calculated to
ensure proper functionality under launch
conditions.
The piezoelectric actuators shall
develop a recordable level of electric
potential.
Preliminary testing will ensure a potential is
developed when bimorph piezoelectric actuators
are deformed.
Test
The microprocessor shall record and
store all voltage, current, and visual
data for duration of flight.
Arduino microprocessor will be programmed and
checked to ensure proper collection of flight data
prior to testing.
Demonstration
The camera shall record all activity the
LED experiences.
The camera will be checked for functionality and
successful integration into electrical system prior to
testing.
Demonstration
Inspection
Test
Analysis
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User’s Guide Compliance
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Magnitude of mass to be determined by CDR
CG – to be determined based on design,
dictated by pre-CDR testing and validation
Low voltage electrical components used
No ports required
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Structural Subsystem
Christopher Elko
Structural Components
Rigid Mounting Deck
Support Column
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Energy Harvesting Subsystem
Christopher Elko
Piezoelectric Actuators
Piezoelectric Strip
Aluminum Cantilever
Fastener
Support
Block
Mass
Redundant
Assembly for
Multi-plane
Vibration
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Piezoelectric Actuators
Mounted to Lower Deck
Attached with Fastener
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Electrical Power Subsystem
Danielle Jacobson
Block Diagram
LED
High-G
Accelerometer
High-G
Accelerometer
Piezoelectric
Power Output
Piezoelectric
Power Output
Rectifier
Rectifier
Arduino
Microcontroller
G-Switch
LED
Camera
Low-G
Accelerometer
Low-G
Accelerometer
Power
Supply
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Microcontroller
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Arduino ATMEGA328 Microprocessor (Open Source)
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Record and store data on 2GB SD card
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Vibration data from accelerometers
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Voltage output from piezoelectric materials
Powered by four (4) AA replaceable batteries
Operating Voltage
5V
Input Voltage
6-20V
Digital I/O Pins
14 (6 can provide PWM output)
Analog Input Pins
6
DC Current per I/O Pin
40mA
DC Current for 3.3V Pin
50mA
Flash Memory
32KB 0.5KB used by boot loader
SRAM
2KB
EEPROM
1KB
Clock Speed
16MHz
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Accelerometers
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Two (2) Low-G Accelerometers
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Analog Devices ADXL206 Dual-Axis
Two (2) High-G Accelerometers
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Analog Devices ADXL278 Dual-Axis
Low-G Accelerometer
High-G Accelerometer
+/- 5g
+/- 35g
312 mV/g
27mV/g
Output Type
Analog
Analog
Noise Density
110 µg/rtHz
180 µg/rtHz
-40°C to 175°C
-40°C to 105°C
13mm x 8mm x 2mm
5mm x 5mm x 2mm
4.25-5.25 V
4.25-5.25 V
700 µV at VS=5V
2.2mA at Vs=5V
Range
Sensitivity
Temperature Range
Size
Operating Voltage
Power
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Bridge Rectifier and G-Switch
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Bridge Rectifiers
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Four (4) Diode Schottky 1A 20V MBS-1
Speed
Recovery ≤ 500ns
Current
1 Amp
Voltage
20V Max at Peak Reverse
Temperature Range
-55°C to 150°C
G-Switch
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One (1) Omron Basic Roll Lever Switch SS-5GL2
Operating Force
50 gf
Contact Rating
5A @ 125 VAC
Voltage
20V Max at Peak Reverse
Temperature Range
-25°C to 85°C
Weight
1.6 g
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Visual Verification Subsystem
Kelly Collett
Block Diagram
Piezoelectric
Wire Output
LED
EPS
Camera
Power
Supply
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Camera Specifications
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Runs on 12VDC, 100mA
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Size: 0.98” sq. x 0.8”
IMAGING SPECIFICATIONS
Imager Manufacturer
Sony
Lines
420
Lux
0.0003
LENS SPECIFICATIONS
Max FOV (degrees)
72
Pinhole
Yes
Super B/W Microvideo
Pinhole Camera
Amps DC (mA)
100
Power Supply Included
No
http://www.supercircuits.com/Se
curity-Cameras/Micro-VideoCameras/PC180XP2
Volts DC Input
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POWER REQUIREMENTS
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LED Specifications
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5mm through-hole LED
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360-degree viewing angle
Low power consumption
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General Specifications
Lumen
4.5
Viewing Angle
360 deg
Wattage Consumption
0.064 W
Color
Cool White
Color Temperature
7350 K
White 5mm LED
http://www.superbrightleds.com/
moreinfo/component-leds/5mmwhite-led-360-degree-viewingangle-4500-millilumens/341/1288
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Christopher Elko
Prototyping Plan
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STR
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Structural Subsystem will be designed and analyzed
primarily using CAD and FEM techniques
Prototype to be constructed and tested for fitment and
mounting methods
PEA
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Piezoelectric actuators will be tested to determine
deformation limits and optimal deformation for energy
harvesting
Mounting/bonding methods to be explored upon
construction of first prototypes
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Prototyping Plan continued
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EPS
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Electronic interfaces will be table-tested with breadboard
and reconfigurable components
Testing will help to determine system capabilities
VVS
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Testing will help to determine system capabilities and
effects on other subsystems
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Prototype Risk Assessment
Subsystem
Risk/Concern
Action
STR
Concerns exist about
clearance and
component mounting
Prototype all interfaces
with STR to ensure
integrity
PEA
Bond between PE
actuators and aluminum
must not fail
Test various bonding
materials and application
methods
EPS
Functionality of
microcontroller must be
verified by CDR
Prototype controller on
bread board to verify
function
VVS
LED must light, camera
must not fail to record
actions of LED
Test LED with PEA to
verify power draw;
test camera to ensure
functionality
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Kelly Collett
Organizational Chart
Danielle Jacobson
Christopher Elko
Electrical Systems Lead
Structural Lead
Machining
CAD Designer
Dr. Jin Kang
Faculty Advisor
Kelly Collett
Visual Verification Lead
Drexel Space
Systems Lab
Testing
Project Support
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Schedule
November 2011
RockSat Deadlines • Drexel Deadlines
11/3
Order parts
Piezo samples, electronics, structural materials
11/7
PDR due
11/14
Senior Design Written Proposal due
Begin Testing Samples (vibe, electronics)
11/17
Senior Design Proposal Presentation
11/21
Online Progress Report due
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Schedule continued
December 2011 – January 2012
Continue testing and verification of all structures and
parts for use in proposed assembly
• Order additional parts as needed
• Make necessary modifications
12/8
CDR due
1/9
Flights Awarded
1/30
Online Progress Report due
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Schedule continued
Estimated Spring Schedule
February
Continue testing and integration
2/6 – Midterm Draft Report due
2/13 – Subsystem Testing Reports due
2/27 – Progress Presentation to Faculty Advisor
March
Continue testing and integration
3/12 – Online Progress Report due
3/19 – Project Progress Report due
April
3/9 – Senior Design Project Abstract due
4/15 – Payload Canister Received
Integration of components with canister
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Schedule continued
Estimated Spring Schedule, continued
April, continued
First Full Mission Testing (vibration, etc.)
4/23 – First Full Mission Simulation Test Report Presentation due
May
Continue Full Mission Testing and modifications
Weekly teleconferences
5/14 – Final Senior Design Project Report due
5/21 – Final Project Presentation
5/28 – Launch Readiness Review (LRR) Presentation due
5/30 – College of Engineering Project Competition
June
Wallops
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Budget
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Spending to date: $94.44
Estimated final total: $673.93
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Major Cost Contributors
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Digital Camera - $109.99
Piezoelectric Components - $150
Major Time Contributors
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Piezoelectric Components – 7-10 days
Accelerometers – 7-10 days
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Budget continued
Item
Subsystem
Supplier
Cost
Lead Time
12"x12“
Polycarbonate Sheet
STR
McMaster-Carr
$7.23
1 day
+/- 35g Accelerometer
EPS
DigiKey
$17.23
7-10 days
+/- 3g Accelerometer
EPS
DigiKey
G-Switch
EPS
DigiKey
Arduino ATmega 128
microprocessor
EPS
Bridge rectifier
EPS
DigiKey
0.62
7-10 days
Piezo Electric Parallel
Bimorph Actuator
PEA
Steminc
$19.98/set of 2
7-10 days
Digital Camera
VVS
Super Circuits
$109.99
3-5 days
7-10 days
$2.15
7-10 days
7-10 days
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Budget continued
Item
Subsystem
Supplier
Cost
Lead Time
LED Lights
VVS
SuperbrightLEDs.com
$1.59
3-5 days
TBD PIEZO MAT'L
PEA – testing
TBD
$75
TBD
TBD PIEZO MAT'L
PEA – testing
TBD
$75
TBD
TBD PIEZO MAT'L
PEA – final installation
TBD
$150
TBD
TBD [DigiKey]
$50
TBD
TBD [DigiKey]
$50
TBD
McMaster-Carr
$17.91
1 day
TBD [McMaster]
$50
TBD
TBD CIRCUITRY
EPS – testing
COMPONENTS
TBD CIRCUITRY
EPS – final installation
COMPONENTS
1/8" x 1" Rectangular
STR
Aluminum Stock
TBD STRUCTURAL
STR
MATERIALS
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Sharing Logistics
Temple University
• Plan for Collaboration
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Email, phone, campus visits
Full model designed in
SolidWorks for fit check
DropBox/Google Docs for
file sharing
Structural interface
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Consider clearance
Joining method
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What’s Next?
Next Steps
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Conduct functionality tests of
subsystems
PEA material strength testing
• EPS functionality test
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Determine final materials to be used
Procure parts and begin assembly
Fabricate structures for assembly
60
Questions?