EarTh HOrizon Sensor
Spring Final Review
Team
Noah Buchanan
Matthew Busby
Matthew Cirbo
Taylor Dean
Jesse Keefer
Patrick Klein
Thomas Konnert
Cole Oppliger
Neal Stolz
7/12/2016
Customers
Joe Breno
Randy Owen
Advisor
Dr. John Farnsworth
University of Colorado Aerospace Engineering Sciences
1
Outline
• Overview
• Design Description
• Testing Overview and Results
– Software
– Algorithm
– Electrical
– Mechanical
• Systems Engineering
• Project Management
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
2
Attitude Sensor Background
Sun Sensor
Senses incoming sunlight to
determine direction to the sun
Earth Sensor
Senses the location of Earth by
distinguishing it from the space
background
Star Tracker
Measures the positions of stars
using a camera and compares to
database of known locations
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
3
Project Purpose
• Sun sensors are inaccurate
• Star trackers are too expensive
• Surrey Satellite Technology’s customers desire a
Goldilocks solution
– Not too expensive
– Accuracies between that of sun sensors and that of a
star tracker
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
4
Mission CONOPS
Example Images:
Orbit
Reference
Nadir
Observation
Corrected
Attitude
Roll Perturbation
Pitch Perturbation
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
5
CONOPS
ETHOS SENSOR
PACKAGE
CAMERA’S FIELD
OF VIEW
SIMULATED EARTH DISK
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
6
ETHOS CONOPS
Reference
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
7
ETHOS CONOPS
Reference
Pitch Deflection
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
8
ETHOS CONOPS
Reference
Pitch Deflection
Roll Deflection
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
9
CONOPS
POWER SUPPLY
BEAGLEBONE BLACK
MICROCOMPUTER
FLIR TAU 2 IR CAMERA
INCLINOMETER
POWER REGULATION BOARD
(OBSCURED BY SENSOR HOUSING)
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
10
CONOPS
SIMULATED
SPACECRAFT
SIMULATED SPACECRAFT COMMS PORT
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
11
FBD
KEY
IR Radiation
ETHOS
Beaglebone Black
Microcomputer
Clock Line and
Pixel Data
FLIR Tau 2
IR Camera
Voltage to
camera
[5 V]
Bit-bang
Software
Interface
Digital I/O
Pins
Image Data
sent line by line
Voltage to Beaglebone Black [5 V]
Power Distribution Board
Voltage
Sensor
Temperature Data
[ ± 1° C ]
Digital Power Board
Output Voltage
[ ± 0.006 V ]
SPI
Internal Data
Storage
Voltage to
Power Board
[22-34 V]
Overview
7/12/2016
ETHOS
Software
Nadir
Displacement
Vector
Communication
Protocol
External
Hardware
Component
UART
Nadir Displacement
Vector and
Health Telemetry
Commands
to send data
External
Power
Supply
Data
Flow
ETHOS
Hardware
Attitude
Determination
Software
(ADS)
Temperature
Sensor
Power
Flow
Simulated
Spacecraft
Command and
Data Handling
[Laptop]
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
12
Broken Camera
•
What Occurred: Hooked up camera to a power supply and shorted the camera due
to an overvoltage
•
Error Source: The power supply did not have a user-friendly interface and the gatorclips were not insulated
• Analog voltage readout
• Used a multi-meter prior to setup to read power supply voltage
•
After Test: Hooked up power supply to oscilloscope
• Large AC signal (+ 3V)
• Mean voltage was around desired voltage – Multi-meter read ‘correct’ voltage
•
Project Impact: Only one partial set of images was obtained for the 750 km case
• Can not be replaced/repaired in time
• Difficult to verify error model - DR.2.1.1
• Can not run full system test
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
13
Levels of Success
ERROR < 0.5
DEGREES
INCORRECT DATA
FLAGGED
COMMUNICATION
VIA CAN PROTOCOL
VECTOR
CALCULATION
FREQUENCY OF
12-30 Hz.
200 MINUTES OF
DISPLACEMENT
DATA RECORDED
COMMUNICATION
< 388 KBPS
4
3
ALGORITHM
RETURNS
DISPLACEMENT
ANGLES
2
DATA SUCCESSFULLY
READ FROM
SENSOR
1
Overview
7/12/2016
200 MINUTES OF
HEALTH TELEMETRY
RECORDED
OPERATIONAL IN
ECLIPSE OF 35 MIN
Design
VOLUME ≤
4.21”X3.74”X2.48”
MASS < 600 g
Testing
HEALTH SAMPLED
≥ 0.5 Hz
ACCEPT 22-34 V
MAX DRAW OF 5 W
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
14
Software Overview
•
Get image from camera
•
Calculate attitude from image
•
Sample voltage and temperature
•
Respond to serial communications
•
Save data to log
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
15
Software Overview
BeagleBone Black Microcomputer
DIO Pins
Tau 2
1. IR Camera (Tau 2) captures frame and sends
data to the microcomputer (BeagleBone Black)
Microcontroller
2. Onboard microcontroller (PRU) reads the pins
and saves data to RAM
RAM
CPU
3. CPU is prompted to read the data in the RAM
4. Attitude is calculated and saved to a log file
Flash
Memory
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
16
Getting an Image
CMOS
protocol
DATA0-7 (8 lines)
FRAME_VALID
PRU
?
LINE_VALID
FLIR Tau 2
CPU
CLK
GND
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
17
PRU and CPU Interfaces
• PRU shared RAM
– Memory configurable to 64 MB
– Unable to configure access for CPU
• Full DDR RAM
– Slower access from PRU
– Missing data due to non-contiguous blocks of memory
• PRU data RAM
– Very fast access from PRU
– Limited to 10% of required memory
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
18
Accessing the Image Data
IR
Camera
New
Frame
Line
PRU
Write Write
Ack Data
ack:
empty
line1
line0
line12
block1
block0
data
RAM
Line12
0
Line
Read & Read
Clear
Data
Ack
CPU
Overview
7/12/2016
Write
Data
Line 1
Line 11
Unused
memory
Read
Data
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
19
Image Capture Results
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
20
Image Capture Issues
•
Missing lines
– < 1% of frames
– Likely due to CPU latency
• Interrupt-driven, or
real-time operating system
•
Missing pixels
– ~50% of rows are missing a pixel
• Untested code fixes
•
Noise
– Unknown origin
• Algorithm ignores noisy pixels
•
Offsets
– FRAME_VALID line incorrectly set
• Hardware connector issue
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
21
Data Rate Verification
• Purpose: Test the data rate of the main
program to verify 12 Hz requirement is met
(DR.2.1.2)
• Results:
– 97.5% of the time is spent getting an image
• Tested using gprof profiling tool
• Needs to wait until new frame is output
– Main loop runs at 7.5 Hz consistently
• Tested by timing execution of 100 iterations
• Only grabs ¼ frames from camera (at 30 fps)
• Does not meet 12 Hz requirement
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
22
Health Telemetry Verification
• Purpose: Verify main program samples
voltage and temperature (DR.2.2.1) and meets
the required rate of 0.5 Hz (DR.2.2.2)
• Results:
– Updated inside main loop (7.5 Hz)
– Temperature sampled using internal temperature sensor
• Measures temperatures between 0 and 90 C
• One degree Celsius resolution
– Voltage sampled using external ADC
• Communicates with micro-computer via SPI
• Resolution of ± 0.009 V
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
23
Communication
• CAN
• Serial Interface with RX and TX pins
• Pins mux on Beaglebone to enable the CAN lines
• Data sent through processor but no signal from pins
• Potential issue in the kernel
• UART
• Surrey supports CAN-UART connections
• Same pins as CAN
• Code already developed from earlier in project
TX RX
Overview
7/12/2016
Design
Location of the UART
CAN
pins
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
24
Communication Verification
• Purpose: Data rate is less than 388 kbps
• Results:
– Baud rate set to 57,600 baud
– Logic analyzer connected between microcomputer
output and different microcomputer input
• Data rate measured by logic analyzer to be 57.6 kbps
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
25
Algorithm Design Solution
Find Horizon
Threshold Value
Horizon
Edge
Detection
Best-fit
Equation
Calculate
Displacement
Angles
Overview
7/12/2016
Design
Search for Edge
Circular least squares
Calculate
Displacement Angles
Correct
Displacement Angles
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
26
Find Average Pixel Intensity
B
Purpose: Define an intensity
value to represent the Earth
horizon
Method:
1. Find mean intensities on
each side of image
2. ‘Hottest’ side is set as
Earth, ‘coldest’ is space
B
3. Threshold is set as
0.85*(Hottest Average)
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
27
Algorithm Design Solution
Find Horizon
Threshold Value
Horizon
Edge
Detection
Best-fit
Equation
Calculate
Displacement
Angles
Overview
7/12/2016
Design
Search for Edge
Circular least squares
Calculate
Displacement Angles
Correct
Displacement Angles
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
28
Search For Edge
Purpose: Use threshold to find
horizon edge location
Method:
1. Begin search from
‘space’ side
2. Find pixel with intensity
≥ threshold
3. Verify edge pixel
4. Use edge location to
constrain search for
next pixel
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
29
Edge Pixel Verification
Purpose: Use basic logic to
refine edge pixel list
Method: Check that pixels
beyond current edge pixel have
intensity ≥ threshold
Edge verification prevents
minor noise from interfering
with edge detection
Least Squares
Edge Pixel
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
30
Algorithm Design Solution
Find Horizon
Threshold Value
Horizon
Edge
Detection
Best-fit
Equation
Calculate
Displacement
Angles
Overview
7/12/2016
Design
Search for Edge
Circular least squares
Calculate
Displacement Angles
Correct
Displacement Angles
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
31
Circular Least Squares
Purpose: To fit a circle to the
edge pixels and return the
radius and center location
Method: Simplified least
squares algorithm prevents the
use of matrix math
Least Squares
Edge Pixel
Linear Fit
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
32
Circular Least Squares
Purpose: To fit a circle to the
edge pixels and return the
radius and center location
Method: Simplified least
squares algorithm prevents the
use of matrix math
Least Squares
Edge Pixel
Linear Fit
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
33
Circular Least Squares
Purpose: To fit a circle to the
edge pixels and return the
radius and center location
Method: Simplified least
squares algorithm prevents the
use of matrix math
Least Squares
Edge Pixel
Linear Fit
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
34
Algorithm Design Solution
Find Horizon
Threshold Value
Horizon
Edge
Detection
Best-fit
Equation
Calculate
Displacement
Angles
Overview
7/12/2016
Design
Search for Edge
Circular least squares
Calculate
Displacement Angles
Correct
Displacement Angles
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
35
Calculate Displacement Angles
Purpose: Determine pitch and
roll from circular least squares
fit
y
Horizon Distance
from Center of
Image
x
Pitch
Pitch Angle
Rc
Focal Plane
Earth
Center
Focal Length
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
36
Calculate Displacement Angles
Purpose: Determine pitch and
roll from circular least squares
fit
y
x
æ xc ö
f = -tan ç ÷
è yc ø
Roll
-1
Center of Least Squares Circle
7/12/2016
University of Colorado Aerospace Engineering Sciences
37
Algorithm Design Solution
Find Horizon
Threshold Value
Horizon
Edge
Detection
Best-fit
Equation
Calculate
Displacement
Angles
Overview
7/12/2016
Design
Search for Edge
Circular least squares
Calculate
Displacement Angles
Correct
Displacement Angles
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
38
Correct Displacement Angles
Error Table Legend
Purpose: Use a 2D surface fit to
model the errors over operational
range
Overview
7/12/2016
Design
TOTAL ERROR (deg)
ROLL (deg)
Method:
1. Collect clean images for 5°
increments between -20°
and 20° pitch and roll
2. Run images through
algorithm and determine
errors
3. Use a 2D surface
interpolation of the errors
to correct future
measurements
Error < 0.5°
0.5° ≤ Error ≤ 1°
Error > 1°
No Data
Testing
-20
-15
-10
-5
0
5
10
15
20
-20 -15 -10 -5 0
PITCH (deg)
Systems
University of Colorado Aerospace Engineering Sciences
5
10
Proj Management
39
Algorithm Test Results
Error Table Legend
Error < 0.5°
0.5° ≤ Error ≤ 1°
Error > 1°
No Data
0° Roll
0° Pitch
TOTAL ERROR (deg)
ROLL (deg)
-5° Roll
-15° Pitch
-20° Roll
0° Pitch
-20
-15
-10
-5
0
5
10
15
20
-20 -15 -10 -5 0
PITCH (deg)
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
5
10
Proj Management
40
Algorithm Test Results
Error Table Legend
Large errors tend to
involve images with low
contrast between
horizon and background
Error < 0.5°
0.5° ≤ Error ≤ 1°
Error > 1°
No Data
Large pitch angles cause horizon edge
to approach the edges of the image.
Lens distortion increases errors at the
large pitch angles
ROLL (deg)
TOTAL ERROR (deg)
-20
-15
-10
-5
0
5
10
15
20
-20 -15 -10 -5 0
PITCH (deg)
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
5
10
Proj Management
41
Electrical Overview
•
Driving Requirements:
– DR.3.5 - Accept 22-34 V DC
– DR.3.6 - Use no more than 5 W total
– DR.2.2 - Monitor camera and BeagleBone input at a rate of 0.5 Hz
• Functionality:
Needs to convert
and monitor input
voltages to
Acceptable levels
for ETHOS’s
components
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
42
ETHOS Electrical Design – Version 1
Problems:
• Relays can fail
easily in space
• Pre-charged
capacitor was poor
design – wouldn’t
last through
launch
• No ADC design
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
43
ETHOS Electrical Design – Version 2
Problems:
• IR Camera current spikes caused large voltage transients
• No ADC design
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
44
ETHOS Electrical Design – Final
R1 = 1 kΩ
R2 = 1 kΩ
R3 = 0.1 kΩ
C1 = 4.7 μF
C2 = 4.7 μF
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
45
Testing – Total Power Draw
Verifying power use is under 5W total:
• Purpose: Characterize DC-DC convertor’s efficiency under operating loads and
ensure at least 80% efficiency
•
Method: Monitor power supply’s input power draw and compare to output power
dissipation across equivalent resistors
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
46
Testing – Total Power Draw
Verifying power use is under 5W total:
• Validation: Data sheet claims output efficiencies between 75 – 95%.
•
•
Results:
Input Voltage
[V]
Input Power
[W]
Output Power
Dissipation [W]
% Efficiency
22
1.54
1.46
94.8
34
1.7
1.46
85.6
22
3.96
3.52
88.9
34
4.08
3.52
86.3
Conclusion: The DC/DC convertor is efficient enough to allow ETHOS to meet
DR.3.6 with a 0.42W margin
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
47
Testing – Transient Load
Verifying power-board output voltage under transient loads:
• Purpose: Ensure output voltage stays within 4.4 – 5.25 V when camera’s current
draw increases by 200 mA
• Method: Using N-channel mosfet and a function generator, the camera spike can
be simulated
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
48
Testing – Transient Load
Validation:
Current
ΔI = 0.75 A
Vout
Results:
ΔV = -75 mV
Vmax = 5.23 V
Vout
Vfunction Gen
Vmin =4.41 V
ΔT = 0.281 μS
ΔT = 18 μS
• Conclusion: The voltage regulator can maintain its output voltage within
4.4 – 5.25 V with high repeatability under a worst case scenario
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
49
Final Product: Mechanical
Purpose
• DR.3.3: Volume ≤ 4.21” x 3.74” x 2.48”
• DR.3.4: Mass ≤ 600 g
•
ETHOS Sensor Package
• Volume: 4.21” x 3.74” x 2.48”
• Final mass: 530 g
BREAKOUT
BOARD
BEAGLEBONE
BLACK MICROCOMPUTER
3.74”
2.48”
POWER
REGULATOR
BOARD
FLIR TAU 2
CAMERA
4.21”
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
50
Final Product: Mechanical
Purpose: To meet DR.2.1.2: 0.5˚ error
•
Focal point height: 4.521” ± 0.001”
• Measured via calipers (0.001”
precision)
• Nominal height is 4.555”
• 0.034” error in height
•
•
250 km disk radius: 16.11” ± 0.0004”
750 km disk radius: 9.13” ± 0.0004”
• Known given CNC machine
precision (0.0004”)
•
Total error induced by test stand is
0.11°
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
51
Camera Mounting Error
Purpose: To meet DR.2.1.2: 0.5˚
error
Expected Results:
• Focal point needs to be centered
in circular mount within 0.031”
Circular Mount
5” Diameter
Error: (Measured with calipers)
• X: -0.005” ±0.002”
• Y: -0.010” ±0.002”
• Z: -0.002” ±0.002”
• Total: 0.0145”
•
Focal
Point
Total error induced by mounting
camera is 0.05°
Z
Y
X
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
52
Roll Bracket Error
Purpose: To meet DR.2.1.2: 0.5˚
error
•
Expected Results: Expected 0.21°
of error due to focal point
placement (±0.0625”)
•
Actual Results: Unexpected
thickness from unexecuted
finishing pass resulted in pitch
axis being placed 0.019” off
center
•
Induces 0.06° of error
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
53
Mechanical Results
Purpose: To meet DR.2.1.2: 0.5˚
error
•
Expected Results: Expected 0.21°
of error due to focal point
placement (±0.063”)
•
Actual Results: Focal point is off
by 0.068” ± 0.001”
• Expected to cause 0.22° of
error in final test
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
54
Systems Engineering
Regional
Architecture
Feasibility
Study/Concept
Exploration
Fall
Semester
Concept of
Operations
•
•
Gather
Requirements
from Surrey
Project
Description
(PDD)
Time Line
Overview
7/12/2016
Operations &
Maintenance
Detailed
Design
Retirement/
Replacement
System
Validation
System
Verification
System
Requirements
High-Level
Design
Changes &
Upgrades
Subsystem
Verification
Unit Testing
Software/Hardware
Development
Field Installation
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
55
Systems Engineering
Regional
Architecture
Feasibility
Study/Concept
Exploration
Fall
Semester
Concept of
Operations
•
•
De-scope
project and
begin high level
design (CDD)
Identify critical
project
elements
(camera
interface,
electrical board,
etc.) Time Line
Overview
7/12/2016
Operations &
Maintenance
Detailed
Design
Retirement/
Replacement
System
Validation
System
Verification
System
Requirements
High-Level
Design
Changes &
Upgrades
Subsystem
Verification
Unit Testing
Software/Hardware
Development
Field Installation
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
56
Systems Engineering
Regional
Architecture
Feasibility
Study/Concept
Exploration
Fall
Semester
Concept of
Operations
•
•
Developed
Specific
requirements to
drive design
Developed
design (PDR and
CDR)
Time Line
Overview
7/12/2016
Operations &
Maintenance
Detailed
Design
Retirement/
Replacement
System
Validation
System
Verification
System
Requirements
High-Level
Design
Changes &
Upgrades
Subsystem
Verification
Unit Testing
Software/Hardware
Development
Field Installation
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
57
Systems Engineering
Regional
Architecture
Feasibility
Study/Concept
Exploration
Operations &
Maintenance
Concept of
Operations
System
Verification
System
Requirements
Detailed
Design
Time Line
Overview
7/12/2016
Subsystem
Verification
Unit Testing
Software/Hardware
Development
Field Installation
Design
Retirement/
Replacement
System
Validation
Spring
Semester
High-Level
Design
Changes &
Upgrades
Testing
• Start ordering parts
• Begin development
for hardware and
software
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
58
Systems Engineering
Regional
Architecture
Feasibility
Study/Concept
Exploration
System
Validation
Concept of
Operations
High-Level
Design
Detailed
Design
Overview
7/12/2016
Retirement/
Replacement
Unit testing:
• Camera hardware
interface
• Camera software
interface
• Electrical power board
• Algorithm error
characterization
• Mechanical tolerances
System
Verification
System
Requirements
Time Line
Changes &
Upgrades
Operations &
Maintenance
Subsystem
Verification
Unit Testing
Software/Hardware
Development
Field Installation
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
59
Systems Engineering
Regional
Architecture
Feasibility
Study/Concept
Exploration
Operations &
Maintenance
High-Level
Design
Detailed
Design
7/12/2016
Subsystem verification:
• Full Software
integration
• Electrical power
board integration
• Full mechanical
assembly
System
Verification
System
Requirements
Overview
Retirement/
Replacement
System
Validation
Concept of
Operations
Time Line
Changes &
Upgrades
Subsystem
Verification
Unit Testing
Software/Hardware
Development
Field Installation
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
60
Systems Engineering
Regional
Architecture
Feasibility
Study/Concept
Exploration
Operations &
Maintenance
High-Level
Design
Detailed
Design
7/12/2016
Project limited to
subsystem verification
• Camera became
inoperable
• Unable to continue
any more testing for
system verification
System
Verification
System
Requirements
Overview
Retirement/
Replacement
System
Validation
Concept of
Operations
Time Line
Changes &
Upgrades
Subsystem
Verification
Unit Testing
Software/Hardware
Development
Field Installation
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
61
Systems Engineering
Feasibility
Study/Concept
Exploration
Regional
Architecture
System
Validation
Concept of
Operations
High-Level
Design
Detailed
Design
Time Line
Overview
7/12/2016
Subsystem
Verification
Unit Testing
Software/Hardware
Development
Field Installation
Design
Testing
Retirement/
Replacement
Lessons Learned or Issues
Encountered:
• Constantly be asking
how to verify
requirements
• More information needs
to be gathered for
interfaces on hardware
and software
• Ensure good
communication
throughout team
System
Verification
System
Requirements
Fall
Semester
Changes &
Upgrades
Operations &
Maintenance
Spring
Semester
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
62
Project Management
• Weekly meetings to ensure entire team was up to date on entirety of
project
• Crucial during Fall semester to allow brainstorming and get different
perspectives
• Meeting minutes distributed each week to maintain accountability and
kept entire team informed
• Found that specific tasks and goals were needed. Progress checked formally
each week
• Complete understanding of status of each subsystem needed to properly
assign personnel to needed areas
• Advisor meeting helpful to refocus on priorities
• Time estimates were not reliable due to inexperience
• Suppliers should not be relied on for proper time estimates or sending of
equipment
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
63
Budget
$775
Planned
$1023
Actual
0%
10%
20%
Sensor and Housing
Category
Differences
Difference
Overview
7/12/2016
Design
30%
40%
Electronics
50%
60%
70%
Testing Materials
80%
Printing
90%
100%
Margin
Sensor and
Housing
Electronics
Testing
Materials
Printing
Margin
+349
-444
+328
+14
+248
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
64
Budget
Margin, $1,023
Sensor and
Housing, $2,126
Printing,
$146
Testing
Materials, $901
Electronics, $804
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
65
Estimated Total Cost of Project
LABOR COST
• 30 weeks
• 9 employees
• 15 hours per week
• $31.25 per hour
PROJECT COST
• Material = $5 000
• Overhead rate = 200%
• Labor cost = $ 126,562.50
• TOTAL = $ 258,125.00
Overview
7/12/2016
Design
• Total = Labor * 2 + Material
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
66
7/12/2016
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67
Backup Slides
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FLIR Tau2 Infrared Camera
Spectral
Range
Pixel
Resolution
Design
Requirements
Product
Specifications
8 – 14 μm
7.5 – 13.5 μm
1.75”
160x128
None
FOV
63° x 50°
Displacement
Error
< 0.5°
0.275°
Power
<5.0 W
<1.0 W
Dimensions
4.21” x 3.74” x 2.48”
1.75” x 1.75” x 1.93”
Weight
600 g
72 g
Price
<$5,000
$2,090
7/12/2016
FLIR Tau2 with 7.5 mm lens
University of Colorado Aerospace Engineering Sciences
1.75”
1.93”
69
Inclinometer
• Communicates via Serial Peripheral Interface (SPI)
• BeagleBone Black supports SPI
• Inclinometer is on evaluation board
• SPI accessed through J1 connector
• Connection Issues
• BeagleBone pins not aligned with
evaluation board connector
• Spacing between pins on board connector
(2.00 mm) and BeagleBone (2.54 mm)
SPI Pins
is not the same
SPI Pins
Ground
Power
• Unable to securely connect inclinometer and
BeagleBone
• Tight spacing made it difficult to separate
connections
7/12/2016
University of Colorado Aerospace Engineering Sciences
70
Full System Test
Full System
Test
Electrical
Mechanical
Algorithm
Software
Comms.
• Purpose: Test at perturbation angles and determine the error
associated with each angle combination. Collect data over time
intervals in order to measure the consistency of the system.
• Results: Test stand results will be compared to
inclinometer angles for error calculation.
• Test to be conducted at the Idea Forge
Outline
7/12/2016
Schedule
Electrical
Algorithm
Software
Comms.
University of Colorado Aerospace Engineering Sciences
Mechanical
Budget
71
Procedure
Inclinometer
α
Boresight
Focal Point Height
Horizon Disk Radius
1.
Construct full test stand in
Idea Forge with 16” disk
2.
Measure initial angle of the
test stand
FOV
Horizon Disk Edge
Outline
7/12/2016
Schedule
Electrical
Algorithm
Software
Comms.
University of Colorado Aerospace Engineering Sciences
Mechanical
Budget
72
Procedure
3.
Take data at initial test stand
angle
4.
The roll angle of the test
stand is then adjusted by
rotating the bearing that
holds the camera
Thin-Section Ball
Bearing
Outline
7/12/2016
Schedule
Electrical
Algorithm
Software
Comms.
University of Colorado Aerospace Engineering Sciences
Mechanical
Budget
73
Procedure
5. Test stand pitch angle is
adjusted by rotating steel rods
holding the enclosure
6. Pitch and roll are adjusted
independently and
simultaneously for testing
Outline
7/12/2016
Schedule
Electrical
Algorithm
Software
Comms.
University of Colorado Aerospace Engineering Sciences
Mechanical
Budget
74
Simulated Image vs Test Stand
Lens distortion causes discrepancies on edges
-20° Roll -20° Pitch
Overview
7/12/2016
Requirements
-20° Roll -20° Pitch
Design
Software
University of Colorado Aerospace Engineering Sciences
Algorithm
Testing
75
Determining Roll Angle
y
Roll is the angle between
the sensor y-axis and the
vector from the center of
the sensor frame to the
center of the least
squares circle, (xc, yc)
x
ϕ
æ xc ö
f = -tan ç ÷
è yc ø
-1
(xc, yc)
7/12/2016
Center of Least Squares Circle
University of Colorado Aerospace Engineering Sciences
76
Determining Pitch Angle
y
Calculate Height:
Height = pixelPitch (Vc - Rc )
Calculate Pitch Angle:
x
æ Height ö
q = -tan ç
÷
è FocalLength ø
-1
Vc - Rc
Pitch Angle
Height
FOV
Vc
Rc
Focal Length
Earth center
7/12/2016
University of Colorado Aerospace Engineering Sciences
77
Software: Line Timing, CMOS Protocol
8-bit Double-Clocked YCbCr CMOS mode (‘YCbYCr’ 4:2:2 Cosited)
2/1/2015
7/12/2016
University of Colorado Aerospace Engineering Sciences
78
Software: Frame Timing, CMOS Protocol
2/1/2015
7/12/2016
University of Colorado Aerospace Engineering Sciences
79
Data Log Verification
• Purpose: Verify log file health and attitude data for 200
minutes (DR.2.3.1)
• Results:
– Log file is updated every loop (7.5 Hz)
• Overwrites old data after 200 minutes
– Saves attitude, health, and index
• Full size of file is approximately 4.8 MB
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
80
Camera Hardware Interface
• Uses Hirose DF12(5.0)-50DP-0.5V(86)
– 50 pin high density
– Break Signals out on PCB so that connections can
be made
7/12/2016
University of Colorado Aerospace
Engineering Sciences
81
Software Lessons Learned
•
•
•
•
•
•
•
Allocate enough time for debugging
Have other people look at your code
Work in parallel
Always backup
Organize directory structure
Use absolute paths in scripts
Utilize scripts for common tasks
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
82
Algorithm Lessons Learned
• Reduce error by using an elliptical least squares fit instead of a circular
least squares fit
• Characterize lens distortion to remove lens distortion errors
• Don’t use unnecessary software packages
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
83
Electrical Lessons Learned
• Prioritize importance of tests
– Transient load performance was a bigger issue than testing for efficiencies as
the camera could have been damaged by the board, yet this was one of the last
tests
• Test early to provide time for problem mitigation
• Circuit performance on a bread board is not necessarily indicative of final
circuit performance
– Testing power board on a solder board drastically changed performance
• Simply measuring the system’s performance can change the output
– Using the oscilloscope improperly (ie. long cables, 1:1 references, measuring in
the wrong spot) caused poor characterization of final system’s performance
• Ask for help
• Don’t offer to provide system features
– ETHOS team offered to provide voltage monitoring; ended up driving design
significantly
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
84
Mechanical Lessons Learned
• Measure twice cut once
• Verify actual parts match Solidworks models
• Use the CNC machine more
– More accurate than manual mill machines
• Check to make sure tool path is clear
• Make as many cuts at a time preventing
having to re-zero
• Have Fun
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
85
Digital Protractor Test
Purpose:
• To determine mounting bias of the digital protractor on camera mount
Method:
1. Place digital protractor on precision ground angle gauge
2. Record angle displayed by digital protractor
3. Step through blocks (1/4° through 30°) to determine bias
Expected Results:
Consistent offset in digital protractor
output when compared to angle gauge
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
86
Digital Protractor Bias/Error
Purpose: To meet DR.2.1.2: 0.5˚
error, need to verify algorithm
output
Expected Results: Accuracy in pitch
and roll axis to 0.1°
Results: Protractor has +0.1° bias
past 20°. Inability to mount
protractor to camera bracket
resulted in up to 0.3° deviation in
measurements
Associated Error: Up to 0.3° in each
axis
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
87
ADC Testing
Provide power board output trending capabilities:
• Purpose: Provide voltage reading for output of the power board to provide
trending relating to temperature changes
• Method: Use of an ADC, voltage divider, and a voltage reference chip to provide
digital voltage measurements
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
88
ADC Testing
Provide power board output trending capabilities:
2∗ 𝐷𝑖𝑔𝑖𝑡𝑎𝑙 𝑂𝑢𝑡𝑝𝑢𝑡 𝐶𝑜𝑑𝑒 ∗3 𝑉
1024
•
Validation: 𝑉𝑚𝑒𝑎𝑠𝑢𝑟𝑒𝑑 =
•
Results:
•
Conclusion: The ADC has an accuracy of + 0.009 V at a rate of 7.5 Hz which meets
DR.3.1.2 with a margin of 1500%
Overview
7/12/2016
Design
Testing
Systems
University of Colorado Aerospace Engineering Sciences
Proj Management
89