1
Project Bliss
Boundary Layer In-Situ Sensing System
Customer
Dr. Suzanna Diener-Northrop
Grumman
Faculty Advisor
Dr. Donna Gerren
Team
Kyle Corkey
Devan Corona
Grant Davis
Nathaniel Keyek-Franssen
Robert Lacy
John Schenderlein
Rowan Sloss
Dalton Smith
2
Outline
• Project Description
▫
▫
▫
▫
Motivation
Project Objectives and Requirements
CONOPS and Functional Block Diagram
Baseline Design
• Evidence of Baseline Feasibility
▫
▫
▫
▫
Logistical
Delivery System
Measurement System
Cloud observation System
• Status Summary
• Strategy for Conducting Remaining Studies
Project
Description
Evidence of
Baseline
Feasibility
Status Summary
Strategy for
Conducting
Remaining
Studies
3
Motivation
• Northrop Grumman needs an in-situ U-,V-, Winertial wind vector field and atmospheric cloud
conditions to verify an atmospheric boundary
layer model.
• The model will be used for environmental
pollution monitoring, forest fire monitoring, and
facilitating soldiers in a battlefield condition.
Project
Description
Evidence of
Baseline
Feasibility
Status Summary
Strategy for
Conducting
Remaining
Studies
4
Project Objectives
• Deliver Northrop Grumman a 3
dimensional U-,V-,W- inertial
wind vector in a measurement
cylinder defined by a 100 meter
radius and 200 meter height
computed from in-situ
measurements.
• Deliver Northrop Grumman
observations of cloud conditions
above the measurement cylinder
for the test period.
Figure 1: Depiction of Measurement
Cylinder
Project
Description
Evidence of
Baseline
Feasibility
Status Summary
Strategy for
Conducting
Remaining
Studies
5
Notable Requirements
• The vector field shall be a cylinder of airspace constrained by a cylinder with a
100-meter radius and 200 meter height. (REQ 1.1)
• Data points shall be collected throughout the entire measurement cylinder with no
more than 30 meters radial spacing between adjacent points. (REQ 1.1.1)
• The measurement system shall collect relative wind data accurate to 1
meter/second, with a resolution of 0.1 m/s.(REQ 1.2)
• A cloud footprint above the measurement cylinder shall be recorded once every 4
seconds, or 1/4 Hz, throughout the experimental timeframe. (REQ 2.1)
• The cloud observation system shall measure the base altitude of clouds below 2 km
for each cloud footprint image. (REQ 2.2)
• Relative wind data and cloud conditions shall be collected over a 10-minute time
frame. (Functional Requirement 3)
• A Certificate of Authorization (COA) shall be obtained to operate any unmanned
aerial system used to collect data during this project. (REQ 4.1.1)
Project
Description
Evidence of
Baseline
Feasibility
Status Summary
Strategy for
Conducting
Remaining
Studies
6
Concept of Operations
Figure 2: BLISS
Wind
Measurement
Concept of
Operations
Project
Description
Evidence of
Baseline
Feasibility
Status Summary
Strategy for
Conducting
Remaining
Studies
7
Experimental Setup
Figure 3:
Experimental
Setup
Project
Description
Evidence of
Baseline
Feasibility
Status Summary
Strategy for
Conducting
Remaining
Studies
8
Functional Block Diagram
Figure 4:
Functional Block
Diagram for
Delivery and
Measurement
System
Project
Description
Evidence of
Baseline
Feasibility
Status Summary
Strategy for
Conducting
Remaining
Studies
9
Functional Block Diagram Cont.
Figure 5: Functional
Block Diagram for
Cloud Observation
System
Project
Description
Evidence of
Baseline
Feasibility
Status Summary
Strategy for
Conducting
Remaining
Studies
10
Baseline Design
GPS and Inertial
Measurement Unit
• Fixed wing UAV with a 5-hole probe
• Autonomous fixed wing UAV flies
through the measurement cylinder
while the 5-hole probe measures the
relative wind.
• Relative wind data is post processed
into U-,V-,W- inertial wind vector
field using inertial data.
5-hole
probe
Figure 6: Depiction of fixed wing UAV with
5-hole probe
http://www.sbg-systems.com/docs/MASC-UAV-Flight-Analysis.pdf
Project
Description
Evidence of
Baseline
Feasibility
Status Summary
Strategy for
Conducting
Remaining
Studies
11
Cloud Observation System
Baseline Design
• 2 Vertical Cameras for Stereovision Distancing of
Cloud Base
▫ Cameras pointed vertical, 20 meters from center of
measurement cylinder on mounting plates
 Mounting plate constructed by the team will insure
images align properly
• 1 Microcontroller to command both cameras
▫ Images will be taken at ¼ Hz
▫ 1 controller insures images are taken at the same time
Project
Description
Evidence of
Baseline
Feasibility
Status Summary
Strategy for
Conducting
Remaining
Studies
12
Cloud Observation Camera Placement
Figure 7: Placement of
cameras for cloud
observation
Project
Description
Evidence of
Baseline
Feasibility
Status Summary
Strategy for
Conducting
Remaining
Studies
13
Critical Elements
• Logistical
• Measurement System
Requirements
▫ Budget Concerns
▫ Obtaining a COA
▫ Machining and Calibrating
▫ Measurement Accuracy
• Delivery System Requirements
▫
▫
▫
▫
• Cloud Observation System
Requirements
Time Requirement
Flight Path
Mass Balance
Power Balance
Project
Description
▫ Cloud Base Altitude
Measurement Error
▫ Constraining Cloud Footprint
Evidence of
Baseline
Feasibility
Status Summary
Strategy for
Conducting
Remaining
Studies
14
Logistical: Monetary Budget
The $5000 budget has constrained and influenced
design options. The baseline design is feasible
within this budget.
Subsystem
Estimated Cost (USD)
Delivery
1200
Measurement
2785
Cloud Observation
415
Total
4400
Project
Description
Evidence of
Baseline
Feasibility
Status Summary
Strategy for
Conducting
Remaining
Studies
15
Logistical: Obtaining a Certificate of
Authorization (COA)
• RECUV has a COA for Skywalker X-8 in Pawnee
National Grassland for flight altitudes over 200 meters
• Must be modified for autopilot and registration Nnumber
• James Mack of RECUV has offered to amend the COA
for Project BLISS
Project
Description
Evidence of
Baseline
Feasibility
Status Summary
Strategy for
Conducting
Remaining
Studies
16
Delivery System Driving Requirements
• Measurement Spacing –> Drives the flight path -> Drives UAV, Motor,
UAV components
▫ REQ 1.1: The vector field shall be a cylinder of airspace constrained by a cylinder
with a 100-meter radius and 200 meter height.
▫ REQ 1.1.1: Data points shall be collected throughout the entire measurement
cylinder with no more than 30 meters radial spacing between adjacent points.
• Measurement Duration -> Drives power needs -> Drives battery
choice
▫ FN3: Relative wind data and cloud conditions shall be collected over a 10-minute
time frame.
▫ REQ 3.1: The delivery system shall be able to continuously operate for a 11-minute
time frame (10% safety factor).
• Legality of Flying -> Drives UAV Choice, Testing Location
▫ REQ 4.1.1: A Certificate of Airworthiness (COA) shall be obtained to operate any
unmanned aerial system used to collect data during this project.
Project
Description
Evidence of
Baseline
Feasibility
Status Summary
Strategy for
Conducting
Remaining
Studies
17
Delivery System: Airframe
• Skywalker X8 Airframe
▫ RECUV has an existing COA with this
aircraft that can be modified for
Project BLISS.
▫ Pusher Prop
▫ 2.7 kg payload capacity meets mass
budget requirements.
▫ Minimum 30 meter turning radius at
cruise allows for helical flight path to
take measurements.
▫ Maximum cruise velocity of 24
meters/second allows for completing
of flight path in 10 minutes.
Figure 6: Skywalker X-8 Airframe
http://www.hobbyking.com/hobbyking/store/__27132__Skywalker_X_8_
FPV_UAV_Flying_Wing_2120mm.html
Project
Description
Evidence of
Baseline
Feasibility
Status Summary
Strategy for
Conducting
Remaining
Studies
18
Fixed Wing UAV Components
Component
Weight (g)
Internal Volume (cm3)
Cost (USD)
Airframe-Skywalker X8
800
10815 (Payload Capacity)
163
Autopilot-3DR
Pixhawk
55
63.16
475
Brushless Motor
177
52.69
42
LIPO Batteries
1100
291.06
56
Propeller
60
N/A
3
Electronic Speed
Controller
45
52.37
25
Servos
90
N/A
30
Raspberry Pi
40
80.92
40
Total
2367
540.2
834
Project
Description
Evidence of
Baseline
Feasibility
Status Summary
Strategy for
Conducting
Remaining
Studies
19
▫
•
•
35 points/layer * 7 layers
= 245 total points
Radius, velocity and bank
angle were optimized to
aircraft capabilities, time
and volumetric constraints
Two flight plan types were
considered due to bank
angle and turning radius
constraints
▫ Overlapping circles
▫ Helix
2
𝑟=
𝑣
𝑔 ∙ tan 𝜃
Project
Description
2D Point Distribution
•
30 meter diameter circles
were placed inside of a
cross section of the cylinder
The intersections of these
circles create points which
are radially spaced by 30
meters
Helix
•
Overlapping Circles 2D Point Determination
Flight Path Determination
Bank angle, θ
Skywalker X8 Stall
Speed (m/s)
30°
10
45°
12
Evidence of
Baseline
Feasibility
Status Summary
Strategy for
Conducting
Remaining
Studies
20
Flight Path
Finalized 3D Flight Path
Flight Path Components
Body
Velocity
Components
Outer
Helix
Middle
Helix
Inner
Helix
Short
Turn
Around
Large
Turn
Around
𝑢
𝑣 =
𝑤
𝑚
16.48
𝑢
𝑣 =
𝑤
𝑚
15.46
𝑢
𝑣 =
𝑤
𝑚
13.92
𝑢
𝑣 =
𝑤
𝑚
14.0
𝑢
𝑣 =
𝑤
𝑚
15.0
𝑠
𝑚
𝑠
𝑚
0.83
𝑠
𝑠
𝑚
𝑠
𝑚
1.17
𝑠
0
Magnitude
of Body
Velocity
𝑉 = 16.5
𝑠
𝑚
𝑠
𝑚
1.48
𝑠
0
𝑚
𝑠
𝑉 = 15.5
𝑚
𝑠
𝑚
0
𝑠
0
𝑚
𝑠
𝑉 = 14.0
𝑠
𝑚
𝑠
𝑚
0
𝑠
0
𝑚
𝑠
𝑉 = 14.0
180 m
200 m
𝑠
0
𝑚
𝑠
𝑉 = 15.0
𝑚
𝑠
Maximum
Roll
17.1°
22.2°
33.7°
32.8°
33.2°
Maximum
Pitch
2.89°
4.33°
6.06°
0°
0°
TOTALS
Distance
3963.5 m
2646.5 m
1895.5 m
197 m
568 m
9270.5 m
Flight Time
240.2 sec
170.7 sec
135.4 sec
14.1 sec
37.9 sec
9 min 58 sec
Project
Description
Evidence of
Baseline
Feasibility
Status Summary
Strategy for
Conducting
Remaining
Studies
60 m
120 m
21
Measurement System Driving
Requirements
• Measurement Requirements -> Drives probe design, pressure
transducers, etc.
▫ REQ 1.2: The measurement system shall collect relative wind data
accurate to 1 meter/second, with a resolution of 0.1 m/s.
• Inertial Wind Desired -> Accurate inertial aircraft state must be
known
▫ REQ 1.2.1: Relative wind data shall be post processed in order to
determine the U-, V-, W- inertial wind vectors at each point.
Project
Description
Evidence of
Baseline
Feasibility
Status Summary
Strategy for
Conducting
Remaining
Studies
22
Measurement System: Components
• 5-hole probe
▫ Five differential pressure transducers
• Air density
▫ Static pressure measured with an absolute pressure transducer
▫ Temperature measured with a thermistor
• Aircraft orientation (Euler Angles)
▫ Inertial Measurement Unit (IMU)
▫ Inertial Navigation System (INS)
• Aircraft inertial velocity
▫ Global Positioning System (GPS)
▫ Inertial Navigation System (INS)
Project
Description
Evidence of
Baseline
Feasibility
Status Summary
Strategy for
Conducting
Remaining
Studies
23
Measurement System: Algorithm
Pressure
measurements
from each
hole, static
pressure,
temperature
Calibration
𝑢
𝑣
𝑤
𝑢
𝑣
𝑤
𝑏
𝐼
𝑢
𝑣
𝑤
𝑢
𝑥
𝑊𝑖𝑛𝑑𝐼 = 𝑣 − 𝑦
𝑤 𝐼
𝑧
𝑏
Euler Angles
Differential
transducers, absolute
transducer,
thermistor
𝑇𝑏𝐼
=
𝑇𝑏𝐼
IMU
GPS
INS
Transformation from body to inertial reference frame
𝐼 Subscript I denotes inertial reference frame
𝑏 Subscript b denotes aircraft body reference frame
Project
Description
Inertial
Velocity
Evidence of
Baseline
Feasibility
𝑢
𝑣
𝑤
Body velocity in the
aircraft body reference frame
Status Summary
Strategy for
Conducting
Remaining
Studies
𝑥
𝑦
𝑧
Inertial velocity in the
inertial reference frame
24
Measurement System: Manufacturing
5-hole pitot probe
• Manufactured parts
▫ The front hemisphere
cap
▫ Back cap
▫ Probe supports
• Six purchased parts
▫ Five 17 gauge tubes
▫ One 3 gauge tube
• Press fit together
Project
Description
Evidence of
Baseline
Feasibility
Status Summary
Strategy for
Conducting
Remaining
Studies
25
Measurement System: Pitot Probe
Calibration
Pressure
• Calibration is achieved by collecting discrete data under measurements
conditions similar to what will be encountered in testing. from each hole
Calibration
𝑢
𝑣
𝑤
𝑏
• Calibration procedure exposes the probe to a given flow under a
combination of orientation angles, θ (cone angle) and φ (roll angle).
• In actual testing, the five pressures measured from the probe are turned
into non-dimensional coefficients. Using these independent
coefficients, θ, φ, and the remaining coefficients are determined from a
least-squared approximation of calibration data.
• Geometry is used to derive [u; v; w]b from angles θ and φ.
Orient probe in
wind tunnel at
an angle
-60o≤θ≤60o
and 0o≤φ≤180o
Measure: 5
pressures from
probe, static
pressure of
flow, total
pressure of
flow
Project
Description
Evidence of
Baseline
Feasibility
Calculate nondimensional
coefficients
Status Summary
Save
coefficients
in a matrix
Strategy for
Conducting
Remaining
Studies
26
Measurement System: Rotation
𝑢
𝑣
𝑤
=
𝐼
𝑇𝑏𝐼
𝑢
𝑣
𝑤
𝑏
𝑢
𝑥
𝑊𝑖𝑛𝑑𝐼 = 𝑣 − 𝑦
𝑤 𝐼
𝑧
Euler Angles
GPS Velocity
• Euler angles are used to rotate the body-relative velocity
components to the inertial frame (IMU, INS).
• Inertial velocity components are subtracted from the
relative wind components, resulting in inertial wind data
(GPS, INS).
Project
Description
Evidence of
Baseline
Feasibility
Status Summary
Strategy for
Conducting
Remaining
Studies
27
Measurement System: Accuracy
• All parts of the measurement system introduce some
error
▫
▫
▫
▫
▫
▫
Pressure transducers: ±7 Pa (differential)
Thermistor: ±0.1o C
Static pressure transducer: ±400 Pa (absolute)
Euler Angles: ±2o yaw, ± 0.5o roll and pitch
Inertial velocity: ±0.05 m/s
Calibration angles: ±1o
• Through standard error propagation equation, we are
able to achieve an accuracy of ±
Project
Description
Evidence of
Baseline
Feasibility
Status Summary
m/s
Strategy for
Conducting
Remaining
Studies
28
Cloud Observation System Driving
Requirements
• Cloud Footprint -> Drives Camera Choice, Camera Placement
▫ REQ 2.1: A cloud footprint above the measurement cylinder shall be
recorded once every 4 seconds, or 1/4 Hz, throughout the experimental
timeframe.
▫ REQ 2.1.1.1: Images taken during the test period shall be post processed
to overlay the 100-meter radius circle above the measurement cylinder.
▫ REQ 2.1.1.2: There shall be less than 10% error in radial distance in
constraining the 100-meter radius circle above the measurement
cylinder on the footprint image.
• Cloud Base Altitude -> Drives Camera Choice, Camera Placement
▫ REQ 2.2: The cloud observation system shall measure the base altitude
of clouds below 2 km for each cloud footprint image.
▫ REQ 2.2.2: There shall be less than 10% error in distance of cloud base
altitude for clouds at 2 km.
Project
Description
Evidence of
Baseline
Feasibility
Status Summary
Strategy for
Conducting
Remaining
Studies
29
Cloud Observation System Components
• 2 Cannon Powershot Cameras for Stereovision
Distancing
▫ 24-240mm focal length (84° – 10.3° Field of View)
▫ 20 Megapixels (5176x3882 Resolution)
▫ Automatic Timing “Hack” Tutorials
• 2 8 GB Standard SD Flash Memory Cards
▫ 1000+ 20 Megapixel Image Capacity
• Arduino Uno Controller
▫ Controls image shutter timing
• Cameras pointed vertical, 20 meters from center of
measurement cylinder
Project
Description
Evidence of
Baseline
Feasibility
Status Summary
Strategy for
Conducting
Remaining
Studies
30
Cloud Observation System Error
• 20 Megapixel and 11°FOV is the best choice to achieve desired
accuracy.
• Measurement Error will be reduced by averaging multiple
measurements of same cloud.
Project
Description
Evidence of
Baseline
Feasibility
Status Summary
Strategy for
Conducting
Remaining
Studies
31
Cloud Observation System
• Cloud base altitude measurements will be tested by
ranging a known point 2 km away.
▫ Angle the camera at a mountain peak with a clear line
of sight.
• Constraining the cloud footprint image
▫ Use base altitude measurement and trigonometry
relations to determine pixel location of 100 meter
radius circle.
▫ Will be calibrated during base altitude testing
Project
Description
Evidence of
Baseline
Feasibility
Status Summary
Strategy for
Conducting
Remaining
Studies
32
Status Summary
• Skywalker X-8 fixed wing UAV with machined and
calibrated 5-hole probe to take relative wind
measurements.
• INS system to provide accurate inertial data for
transformation of relative wind to inertial wind.
• 2 Cannon Powershot cameras for stereovision distancing
of cloud conditions above measurement cylinder.
Project
Description
Evidence of
Baseline
Feasibility
Status Summary
Strategy for
Conducting
Remaining
Studies
33
Strategy for Conducting Remaining
Studies
• We will machine a 5-hole probe this semester to make
sure it is feasible at its current size.
• Determining optimal mounting location of 5-hole probe
that will reduce the risk of damage from aircraft landing
while delivering consistent data.
Project
Description
Evidence of
Baseline
Feasibility
Status Summary
Strategy for
Conducting
Remaining
Studies
34
Acknowledgements
We would like to thank all of the PAB, our
advisor Dr. Gerren, our customer Dr. Diener
from Northrop Grumman, Matt Rhode, Trudy
Schwartz, and James Mack for all of their help in
preparing for this PDR.
35
Questions
36
References
•
•
•
•
•
•
•
•
•
•
Telionis, D., and Yang, Y., “Recent Developments in Multi-Hole Probe (MHP) Technology,” 20th
International Congress of Mechanical Engineering, Gramado, RS, Brazil, 2009
Kim, S.H., and Kang, Y.J., “Calibration of a Five-Hole Multi-Function Probe for Helicopter Air Data
Sensors,” International Journal of Aeronautical & Space Sciences, Vol. 10, No. 2, November 2009, pp.
43-61.
Whitmore, S.A., William, T.L., Curry, R.E., Gilyard, G.B, “Experimental Characterization of the Effects of
Pneumatic Tubing on Unsteady Pressure Measurements,” NASA Technical Memorandum 4171, March
1990
“Thermistor Elements, 44000 Series”, Omega,
[http://www.omega.com/Temperature/pdf/44000_THERMIS_ELEMENTS.pdf, Accessed 10/10/14]
“TruStability Board Mount Pressure Transducers, SSC Series”, Honeywell, August
2014,[http://sensing.honeywell.com/index.php?ci_id=151134, Accessed 10/10/14]
“TruStability Board Mount Pressure Transducers, HSC Series”, Honeywell, August 2011,
[http://www.mouser.com/ds/2/187/HSC%20Analog-221530.pdf, Accessed 10/10/14]
“VN-200 Rugged GPS/INS,” VectorNav, [http://www.vectornav.com/products/vn200-rugged, Accessed
10/10/14]
“VN-100 Rugged IMU/AHRS,” VectorNav, [http://www.vectornav.com/products/vn100-rugged,
Accessed 10/10/14]
“Max-M8 Series,” ublox, [http://u-blox.com/en/gps-modules/pvt-modules/max-m8-series-concurrentgnss-modules.html, Accessed 10/10/14]
“Stainless Steel Tubing,” McMaster-Carr, [http://www.mcmaster.com/#standard-metal-tubing/=u4z9lg,
Accessed 10/12/14]
37
References Continued
•
•
•
•
•
•
•
•
•
•
•
Mack, James (Email, 9/10/14-10/12/14)
“Skywalker X-8 FPV/UAV Flying Wing 2120 mm”
[http://www.hobbyking.com/hobbyking/store/__27132__Skywalker_X_8_FPV_UAV_Flying_Wing_2
120mm.html Accessed 10/1/14]
“3DR Pixhawk” [https://store.3drobotics.com/products/3dr-pixhawk [Accessed 10/3/14]
“Turnigy Aerodrive SK3 - 3548-700kv Brushless Outrunner Motor ”
[http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=37260 [Accessed 10/10/14]
“ZIPPY Compact 3700mAh 6S 35C Lipo Pack”
[https://www.hobbyking.com/hobbyking/store/__21415__ZIPPY_Compact_3700mAh_6S_35C_Lipo_
Pack.html Accessed 10/10/14]
“Hitec HS-485HB Deluxe servo 4.8kg/45g/0.22sec”
[https://www.hobbyking.com/hobbyking/store/__9811__Hitec_HS_485HB_Deluxe_servo_4_8kg_45
g_0_22sec.html Accessed 10/10/14]
” Turnigy dlux 55A SBEC Brushless Speed Controller w/Data Logging”
[https://www.hobbyking.com/hobbyking/store __16365__Turnigy_dlux_55A_SBEC_Brushless_
Speed_Controller_w_Data_Logging.html Accessed 10/10/14]
“DSM2 Remote Receiver” [https://www.spektrumrc.com/Products/Default.aspx?ProdID=SPM9545
Accessed 10/13/14]
“Raspberry Pi” [http://www.raspberrypi.org/ Accessed 10/2/14]
“Propeller Basics” [http://www.stefanv.com/rcstuff/qf200203.html Accessed 10/5/14]
"PowerShot ELPH 150 IS Blue." Canon U.S.A. : Consumer & Home Office : PowerShot ELPH 150 IS.
N.p., n.d. Web. 14 Oct. 2014.
38
Back-Up Slides
Project
Description
Evidence of
Baseline
Feasibility
Status
Summary
Strategy for
Conducting
Remaining
Studies
Backup Slides
39
Delivery System Budget
Item
Estimated Cost (USD)
Components
834
Transmitter/Receiver
250
Wiring/Mounting/Accessories
116
Total:
1200
Project
Description
Evidence of
Baseline
Feasibility
Status
Summary
Strategy for
Conducting
Remaining
Studies
Backup Slides
40
Measurement System Budget
Item
Estimated Cost (USD)
Pitot Material
75
Pressure Transducers
400
Inertial Navigation System
2210
Tubing
50
Arduino Due
50
Total:
2785
Project
Description
Evidence of
Baseline
Feasibility
Status
Summary
Strategy for
Conducting
Remaining
Studies
Backup Slides
41
Cloud Observation System Budget
Item
Estimated Cost (USD)
2x Cannon Powershot
ELPH 150 IS Camera
300
Arduino Uno
25
2x 8 GB Sandisk SD Cards
20
1 9v Rechargable Battery
10
400 ft (122 m) 18 Gauge
Remote Wire
30
Camera Mount Supplies
30
Total:
415
Project
Description
Evidence of
Baseline
Feasibility
Status
Summary
Strategy for
Conducting
Remaining
Studies
Backup Slides
42
Fixed Wing UAV: Autopilot
•
•
•
•
•
3DR Pixhawk developed by the PX4 Open-Hardware project.
Open-Hardware reduces cost and allows for modification.
Pixhawk is the most current Open-Hardware autopilot.
Costs $475.
Pixhawk is the most current operational Open-Hardware autopilot
with an active development support community.
Project
Description
Evidence of
Baseline
Feasibility
Status
Summary
Strategy for
Conducting
Remaining
Studies
Backup Slides
43
Ground Station
• Ground Station Computer will be supplied by
group members.
• Radio uplink to UAV will be good up to 1600
meters.
• Ground Station Software is Open-Source and
can be run on a laptop in the field.
• Eliminates cost of Specific Ground Control
Station hardware.
Project
Description
Evidence of
Baseline
Feasibility
Status
Summary
Strategy for
Conducting
Remaining
Studies
Backup Slides
44
Flight Path Trade Study
Weight
Reasoning
Distance-35%
Functional Requirement-Data
must be taken within 10
minutes. If it is necessary to
increase this, time is more
flexible than the spacing of
data points.
Data Points Collected-40%
Turning Radius-25%
Functional Requirement-Data
points must be spaced no
further than 30 meters in any
direction
Score
Breakdown
1
2
3
4
5
Distance
15,00020,000
meters
10,00015,000
meters
7,00010,000
meters
5,0007,000
meters
< 5,000
meters
Data Points
Collected
< 150
150-200
200-220
220-240
> 240
Turning Radius
(Minimum)
< 20
meters
20-29
meters
30-39
meters
40-49
meters
≥ 50
meters
Feasibility of Skywalker X8
performance
Flight Path
Trade
Study
Weight
4 Overlapping
Circles
8 Overlapping
Circles
2 Helix
3 Helix
Distance
35%
2
1
3
3
Data Points
Collected
40%
3
5
4
5
Turning
Radius
25%
4
4
4
3
Total
100%
2.90
3.35
3.65
3.80
Project
Description
Evidence of
Baseline
Feasibility
Status
Summary
Strategy for
Conducting
Remaining
Studies
Backup Slides
45
Project
Description
Evidence of
Baseline
Feasibility
Status
Summary
Strategy for
Conducting
Remaining
Studies
Backup Slides
46
Project
Description
Evidence of
Baseline
Feasibility
Status
Summary
Strategy for
Conducting
Remaining
Studies
Backup Slides
47
Project
Description
Evidence of
Baseline
Feasibility
Status
Summary
Strategy for
Conducting
Remaining
Studies
Backup Slides
48
Project
Description
Evidence of
Baseline
Feasibility
Status
Summary
Strategy for
Conducting
Remaining
Studies
Backup Slides
49
Project
Description
Evidence of
Baseline
Feasibility
Status
Summary
Strategy for
Conducting
Remaining
Studies
Backup Slides
50
Measurement System: Pitot Tubes –
Calibration
• The 5 pressure readings from the probe (one from
each port) can be related to the orientation of the
probe through non-dimensional coefficients
• To do this:
Independent coefficients
▫ Independent non-dimensional coefficients
are calculated as a function of the 5 recorded
pressure values from the probe
▫ dependent non-dimensional coefficients are
calculated as functions of total pressure and
static pressure. Coefficients are stored in a
matrix.
• During testing, the independent coefficients act
as look-up tables, which allow determination of
orientation, total pressure and static pressure.
Project
Description
Evidence of
Baseline
Feasibility
Status
Summary
𝑝2 + 𝑝3 + 𝑝4 + 𝑝5
4
𝑝2 + 𝑝4 − 𝑝5 + 𝑝3
𝑏∅ =
2𝑞
𝑝2 + 𝑝5 − 𝑝4 + 𝑝3
𝑏𝜃 =
2𝑞
𝑞 = 𝑝1 −
Strategy for
Conducting
Remaining
Studies
Dependent coefficients
𝑝1 − 𝑝𝑡
𝐴𝑡 =
𝑞
𝑞
𝐴𝑠 =
𝑝𝑡 − 𝑝𝑠
Backup Slides
51
Project
Description
Evidence of
Baseline
Feasibility
Status
Summary
Strategy for
Conducting
Remaining
Studies
Backup Slides
52
Measurement System: Error
propagation
δV δФ δΘ →
δP0 δT δΔP → δV
Pressure
measurements
from each hole
Calibration
𝑢
𝑣
𝑤
δu
δv
δw
𝑏
𝑏
𝑢
𝑣
𝑤
𝐼
δφ
δu
→
δθ
δv
δψ
δw
δu
δv
δw
𝑏
=
𝑇𝑏𝐼
𝑢
𝑣
𝑤
𝑏
δu
δv
δw
𝐼
𝑢
𝑥
𝑊𝑖𝑛𝑑𝐼 = 𝑣 − 𝑦
𝑤 𝐼
𝑧
Euler Angles
Project
Description
Evidence of
Baseline
Feasibility
Status
Summary
Strategy for
Conducting
Remaining
Studies
𝐼
δ𝑥
δ𝑦 → δ𝑊𝑖𝑛𝑑
δ𝑧
GPS Velocity
Backup Slides
53
Measurement System: Pressure
Transducers, Thermistor
• Differential Pressure Transducer – Honeywell HSC
– 010MG
▫ Measurement range -1 to 1 KPa differential
▫ Accurate to 0.25% of total range -> ±5 Pa
▫ Resolution of 0.03 m/s
• Absolute Pressure Transducer – Honeywell SSCMRNN
▫ Measurement range 0 to 160 KPa Absolute
▫ Accurate to 0.25% of total range -> ±400 Pa
• Thermistor Omega 44030 (3000 Ohm)
▫ Measurement range 0° to 75° C
▫ Accurate to ± 0.1° C
Project
Description
Evidence of
Baseline
Feasibility
Status
Summary
Strategy for
Conducting
Remaining
Studies
Backup Slides
54
Measurement System: Inertial Measurement
Unit (IMU)
• An inertial measurement
unit measures Euler angles
to transform the relative
wind to the inertial frame.
• The VN-100 is accurate to 2
degrees in yaw and 1 degree
in pitch and roll.
http://www.vectornav.com/products/vn200-rugged
Project
Description
Evidence of
Baseline
Feasibility
Status
Summary
Strategy for
Conducting
Remaining
Studies
Backup Slides
55
Measurement System: GPS
• The GPS is needed to provide the
inertial velocity of the UAV
• The GPS must be accurate to 1 m/s
or less.
• The MAX M8 Series from u-blox is
accurate to about 0.15 m/s at flight
speeds of 15 to 20 m/s
(9.7 x 10.1 x 2.5 mm)
http://u-blox.com/en/gps-modules/pvt-modules/max-m8-seriesconcurrent-gnss-modules.html
Project
Description
Evidence of
Baseline
Feasibility
Status
Summary
Strategy for
Conducting
Remaining
Studies
Backup Slides
56
Measurement System: Inertial
Navigation System (INS)
• An inertial navigation system
combines an IMU and a GPS
in one unit.
• The VN-200 from VectorNav
provides an accuracy of 2
degrees in yaw and 0.5 degree
in pitch and roll.
• The velocity accuracy is 0.05
m/s
• The drawback is that this
system is $2200. However,
this fits in our budget.
Project
Description
Evidence of
Baseline
Feasibility
Status
Summary
http://www.vectornav.com/products/vn200-rugged
Strategy for
Conducting
Remaining
Studies
Backup Slides
57
Cloud Observation System
Requirements
• Requirements created by studying wind
conditions at 12,000 ft ASL (approx. 2 km AGL)
at Denver International Airport
• Avg. Velocity: 5.54 m/s
Std. Dev.: 2.89 m/s
▫ Assume Normal Distribution: 95th Percentile
Strongest Wind Velocity = 11.32 m/s
• Cloud will move across measurement cylinder in
about 17 seconds
Project
Description
Evidence of
Baseline
Feasibility
Status
Summary
Strategy for
Conducting
Remaining
Studies
Backup Slides
58
Cloud Observation System Camera
Project
Description
Evidence of
Baseline
Feasibility
Status
Summary
Strategy for
Conducting
Remaining
Studies
Backup Slides
Cloud Observation System Mount
Bubble Level
Camera
Bubble Level
Camera
Adjustable Legs
Adjustable Legs
Side View
Project
Description
Evidence of
Baseline
Feasibility
Top View
Status
Summary
Strategy for
Conducting
Remaining
Studies
Backup Slides
Measurement System Electrical Layout
0-3V input
• Arduino Duemilanove
o Power: 9V battery
o ARM Cortex-M3 CPU
o SD card shield to store data
o 12-bit Analog-to-Digital-Converter(ADC)
• 6 transducers
o Power: 3.3V from Arduino
o 0-3V output to Arduino ADC
• Thermistor
o Resistance proportional to temperature
o Determined by Arduino
• Inertial Navigation System
o Power: 5V from
Arduino
o Serial UART
Arduino
output
9V
Duemilanove
Battery
• Total System
w/ SD card
o < 6W
shield
Analog/Serial
Signal
Pitot
Tube
3.3V
6
Transducer
s
Thermist
or
5V
GPS
Euler Angles
Inertial
Navigation
System
Wind
Power Feasibility
Electronic Speed
Controller (ESC)
Battery
6S Lipo
35C
3700mAh
22.2V
55A
Flight
Instructions
5V
Battery
Raspberry Pi
3.7 𝐴ℎ
15 𝑚𝑖𝑛𝑢𝑛𝑡𝑒𝑠
Propeller
665W
700kv
12” x 6”
Rx
Pixhawk
Flight Path Data
3700 𝑚𝐴ℎ ∗ 35 𝐶 = 129500 𝑚𝐴ℎ
Motor
Tx
Ground
Station
Radio
Laptop
= 129.5 𝐴𝑚𝑝 𝑚𝑎𝑥𝑖𝑚𝑢𝑚 𝑐𝑜𝑛𝑠𝑡𝑎𝑛𝑡 𝑑𝑖𝑠𝑐ℎ𝑎𝑟𝑔𝑒 𝑟𝑎𝑡𝑒
∗ 60 𝑚𝑖𝑛𝑢𝑡𝑒𝑠 ∗ 80%(𝑓𝑜𝑟 𝑠𝑎𝑓𝑒𝑡𝑦) = 11.8 𝐴𝑚𝑝 𝑐𝑜𝑛𝑠𝑡𝑎𝑛𝑡 𝑑𝑖𝑠𝑐ℎ𝑎𝑟𝑔𝑒 𝑟𝑎𝑡𝑒
665 𝑊𝑎𝑡𝑡𝑠
= 29 𝐴𝑚𝑝 𝑚𝑎𝑥𝑖𝑚𝑢𝑚 > 11.8 𝐴𝑚𝑝𝑠
22.2 𝑉
700 𝑘𝑣 ∗ 22.2 𝑉 = 𝑚𝑎𝑥𝑖𝑚𝑢𝑚 15540 𝑅𝑃𝑀
∴ 𝑩𝒂𝒕𝒕𝒆𝒓𝒚, 𝑬𝑺𝑪, 𝒂𝒏𝒅 𝒎𝒐𝒕𝒐𝒓 𝒂𝒓𝒆 𝒇𝒆𝒂𝒔𝒊𝒃𝒍𝒆 𝒄𝒐𝒎𝒃𝒊𝒏𝒂𝒕𝒊𝒐𝒏
Delivery System Electrical Layout
Electronic Speed
Controller (ESC)
Battery
6S Lipo
35C
3700mAh
22.2V
55A
Flight
Instructions
5V
Battery
Raspberry Pi
Motor
Propeller
665W
700kv
12” x 6”
Rx
Pixhawk
Flight Path Data
Tx
5V
Ground
Station
Radio
Laptop
• Raspberry Pi
5V
Servos
o Power: 5V battery pack
o On board SD card will hold
flight path instructions
• Servos
• Pixhawk
o Power: 5V
o Power: 5V
o Serial communication with Pixhawk
o Input flight path
• Total System
o Output flight instructions
o <5W
Project Off-ramp: Weathervaning
Aircraft
• It is possible that a 5-hole probe cannot be manufactured to necessary
tolerance
• A Traditional 1-hole pitot probe can be used to compute a 3-D Wind vector
if the aircraft is assumed to be weathervaned and the aircraft state vector is
known.
• Why this method wasn’t originally chosen:
▫ Faculty advice to piggy-back on existing RECUV Skywalker COA with
assistance from James Mack
 The Skywalker weathervanes very slowly due to blended wing body and small
vertical tails.
▫ Must assume that aircraft is weathervaned at each data point
 If the aircraft is not weathervaned, wind vector direction will be incorrect.
Project
Description
Evidence of
Baseline
Feasibility
Status
Summary
Strategy for
Conducting
Remaining
Studies
Backup Slides