CDIO-3 Product Concept
Requirements Team
Oscar Murillo
Leah Soffer
Maggie Sullivan
February 21, 2002
Mission Statement
Project Mission: Demonstrate the
feasibility of electromagnetic control for
formation flying satellites.
Implications:
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Demonstrate
EM Control
Formation maneuvering vehicles
Functional Requirements 1:
the Customer
Formation flying
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Stability in formation
Interchangeable/replaceable modules
Both autonomy and command response
EM control
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“Use magnets to generate the … restoring forces”
“… will allow between 3 and 6 DoF EMFF”
Architectural notes
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High-permeability lightweight solenoid cores
Necessary heat dissipation
Reaction wheels
Functional Requirements 2:
the System
Top-Level: “The system shall…”
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Have interchangeable system modules
Be tested on a realistic facility
Maintain relative separation/attitude
Follow steady course, predetermined or MC
Subsystems
Power
ADS – Sensing
Communication
Testing
Flight computer
ACS - Control
Protection
Integration
EM Trades
3 µ 0 m0
β=
4π α
Pw
ρ c Pc
3µ 0π m05 / 6
ω=χ
B 5 2π
3
Pw
α
πρ s ρ c pc
m0 = l πα ρ s
3
( χnia 2 ) 2
F = µ 0π
2
B4
3
Angular Rate vs. Seperation Distance
2
B-Field vs Core Radius
Angular Rate vs Core Radius
4.00E+01
Angular Rate
3.00E+01
2.00E+01
1.00E+01
0.00E+00
1
2
3
4
Seperation Distance (m)
5
B-Field (Tesa)
Angular Ra te (ra d/se c)
5.00E+01
1.00E-02
4.50E+00
9.00E-03
4.00E+00
8.00E-03
3.50E+00
7.00E-03
3.00E+00
6.00E-03
2.50E+00
5.00E-03
2.00E+00
4.00E-03
1.50E+00
3.00E-03
2.00E-03
1.00E+00
1.00E-03
5.00E-01
0.00E+00
0.01
0.02
0.03
0.04
Core Radius (m)
0.00E+00
0.05
Angular Rate (rad/sec)
6.00E+01
B-Fie ld (Te sa )
An g ula r Ra te
Final Design
Inside spheres:
•Reaction Wheels
•Computer
•Battery
•Coil and Core
•Transmitter/Receiver
Steel Core/Copper Coil
Mass = 5.26 kg
Separation =5m
Length of core = 0.3m
Radius of core =0.03m
Angular Rate = 0.959
rad/sec
B-field = 3.20E-03
Force = 58.12 N
Operations Concept
Programmed response only
Ground-to-vehicle communication
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User-initiated autonomous tests
Realtime telemetry recording and storage
Emergency interrupt sequence
Inter-vehicle communication
Automated depth control
Pros and Cons
Advantages
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3D flight
Simpler test carriage
Reduces danger of crash
Disadvantages
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Instability of water environment
Š Polarity
Š Currents
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Increased drag due to high density of test medium