Transcript Slide 1

D-SUAVE
Deployable Small UAV Explorer
System Architecture
Interim Assignment
Fall 2006
System Architecture
Primary Objective
“To design, fabricate, integrate and verify a RC
controlled UAV capable of being remotely
deployed from the ARES aircraft and flying a
specific flight pattern.”
Mission
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Drop From ARES
Deploy Wings and Maintain Flight
Loiter for 25 minutes over a Lake Collecting Science Data
Return to Ground
Considerations
•
•
7/7/2015
Controlled by a RC Pilot From Ground
Not Tested on ARES itself but from a nacelle on a pole mounted to a truck
System Architecture
Overview of Requirements
7/7/2015
Parameter
Requirement
Motivation
Deployment
Transition to stable cruise
after being deployed at 20
m/s
ARES stall velocity is 17 m/s
Cruise Velocity
12 m/s
5 min/lap, 3600 m/lap
Endurance
25 min
5 min/lap, 4 laps, 5 min for
safe return
Turn Radius
50 m (10 m)
turn 180° over 100 m (RC
pilot controllability)
Vehicle and Package Mass
565 g
ARES performance, historical
payload mass fractions
Payload Mass
75 g
Customer-estimated mass of
self-powered payload box
containing temperature,
pressure and humidity
sensors
Payload Dimensions
5 x 7 x 3 cm
Customer-estimated
dimensions of payload box
Payload Location
Part of payload box must be
in contact with the
freestream
Atmospheric sensors must
have access to the air
System Architecture
Integrated Design
Packaged Configuration
Top
Side
Bottom
Partially Deployed
Deployed
Deployment
Packaged
7/7/2015
System Architecture
System Design
D-SUAVE
Vehicle
Tube
Pole
Ground Station
Backbone
Servos
Fuselage
Electronics
Swing
Mechanism
Flight Dynamics
Board
Propulsion
Motor
Propeller
ESC
Wings
Receiver
Battery
Tail
7/7/2015
System Architecture
Power and Electronics
Objective
•
Provide RC Control
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Provide signal communication to ESC and servos
Aircraft is radio controlled by an RC pilot on the ground
Verify Velocity Requirement
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GPS data transmitted to the ground so velocity can be read real time
Velocity must be 12 m/s for at least 25 minutes
Power Flow
Battery
Battery Voltage: 7.4 V
Battery Capacity: 1500 mAh
ESC/BEC
Motor
7/7/2015
Flight Dynamics
Board
Servos
Receiver
Allowed Flight Time: 30 minutes
System Architecture
Electronics and Communication
Ground Transmitter Frequency: 72.5 MHz
Onboard Receiver
ESC/BEC
Onboard Transmitter Frequency: 2.4 GHz
Flight Dynamics
Board
Servos
Onboard
Transmitter
GPS
Antenna
Ground Setup
High Gain
Antenna
High Gain
XBee-Pro
Antenna
Receiver
Ground
Transmitter
7/7/2015
Computer
High Gain
Display
Antenna
High Gain
XBee-Dev
Antenna
Board
System Architecture
Software
On ground
Programming Language: MATLAB
Capable Data Rate: 112500 bps
Onboard
Programming Language: C
GPS Sample Rate: 10 Hz
Control Input Resolution: 1024
Receiver
Control Inputs
Ch 1-8
GPS Data
Analog
Flight Dynamics
Board Processor
RF Modem
Computer Readable Format
Data Processing
(MATLAB)
Velocity
(ASCII)
Control Input
ASCII
Transmitter
Real Time Display
Of Velocity
7/7/2015
RF Signal
Servos
System Architecture
Demonstration of Deployment Requirement
• Integrate equations of motion
Deploy Vehicle Begin Wing
at 20 m/s
Deployment
0s
End Wing
Deployment
0.1 s
Level Flight
at 12 m/s
.5 s
.4 s
Dutch Roll Mode
Spiral Mode
1.5
 [deg]
 [deg]
1
p [deg/sec]
 [deg]
r [deg/sec]
1
p [deg/sec]
 [deg]
r [deg/sec]
0.8
Path Followed by the Aircraft C.G
0.5
0.6
0.4
0.8
0
-1
0
2
4
6
Time [sec]
8
10
z-component
0.2
-0.5
0.6
0
0
0.4
0.2
0 10
5
0
y-component
7/7/2015
200
400
x-component
600
50
100
Time [sec]
150
System Architecture
Deployment Testbed Design
Pole
Attachment Points
7/7/2015
Packaging
System Architecture
Demonstration of Flight Plan Requirements
Propeller Testing Results
• L/D = 11 (lifting line and airfoil data)
• Battery Capacity: 950 mAh to meet endurance requirement
• Propeller efficiencies:
Total Efficiency Comparison
AXI 2208-26
Total Efficiency Comparison
Komodo KH2204-11
0.45
0.45
Theoretical
Experimental
0.4
0.4
0.35
0.35
Total Efficiency
Total Efficiency
Theoretical
Experimental
0.3
0.25
0.25
0.2
0.2
0.15
0.15
0.1
0.1
0.22
0.32
0.42
0.52
Thrust [N]
7/7/2015
0.3
0.62
0.72
0.82
0.22
0.32
0.42
0.52
Thrust [N]
0.62
0.72
0.82
System Architecture
Demonstration of Flight Plan Requirements
Propeller Testing Results
Experimental Total Mass
AXI vs. Komodo
(Motor+Prop+ESC+Battery)
220
Komodo KH2204-11
AXI 2208-26
200
Total Mass [g]
180
160
140
120
100
0.22
0.32
0.42
0.52
Thrust [N]
7/7/2015
0.62
0.72
0.82
System Architecture
Structural Analysis
Materials: Carbon Fiber
Geometry: Hollow Cylinder
Max Load [N]
Max Allowable
Deflection [cm]*
Length
[cm]
Required
Outside Diameter
[mm]
Required
Thickness
[mm]
Wing Spar
10
3.0
60
7.6
1.5
Backbone
10
2.5
50
10
0.5
Max Load at 2g. Designed for stalled landing.
Wing Spar Stress
F
Normal Bending Stress in Cross Section
8
Results
6
•Applied Load F = 10 N
Location Along y-axis [mm]
4
•Max Deflection = 2.72 cm
2
•Max Bending Stress = 20.1 MPa
0
•Max Shear Stress = 0.335 MPa
-2
-4
•Top in tension
-6
-8
-25
7/7/2015
•Bottom in compression
-20
-15
-10
-5
0
5
Stress [MPa]
10
15
20
25
*Found using [1]
System Architecture
Structural Analysis
Objective
• Deploy the wings
• Ensure the wings
open simultaneously
• Lock the wings in place
both when open and deployed
Changes since PDR
• No longer Elastic Band Method
• Spring Method was chosen to deploy the wings
Swing Mechanism Spring
1000
Assumptions
•½ of energy is lost due to friction
•0.018 J of energy is lost due to drag
•Spring gets compressed 37 mm
•Wing Moment of Inertia 0.007
kg*m2
•Folded to Deployed Wing angle is 90o
Spring Constant k (N/m)
900
800
700
600
500
400
300
200
100
0.2
7/7/2015
0.4
0.6
0.8
Wing Deployment Time (s)
1
System Architecture
Demonstration of Mass Requirement
Subsystem
Aerodynamics
Item Description
Wing
63
Wing Spars
15
Fuselage
30
Backbone Spar
10
Tail
20
Wing Deployment Mechanism
40
Fasteners
Electronics
7/7/2015
5-10
Dummy Payload
75
Receiver
30
Servos
20
Flight Dynamics Board
30
GPS Antenna
18
Connectors/Wires
Propulsion
Mass [g]
10-20
Battery
100
Propeller
5-10
Motor
24
ESC
6
Total Vehicle Mass
501-521
Tube Mass
64
Total Mass
?
Additional Notes
Tail design is not included in above slides, but can be seen below.
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Inputs:
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7/7/2015
s.m. = 0.18 (from longitudinal stability
constraint)
bv = 0.10m (from ARES container constraint)
Vv = 0.045 (from historical trends)
bh = 0.1833m (from ARES container
constraint)
ARh = 5.5 (from historical trends and
structural concerns)
Outputs
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xnp = 0.0390 m
xcg = 0.0196 m
ch = 0.033m
Vh = 0.2489
lh = 0.5250 m
bh = 0.1833 m
ch = 0.0333 m
Vv = 0.0450
lv = 0.4085 m
bv = 0.1000 m
cv = 0.1443 m10