SPECTRE
Manufacturing
Status Review
February 5, 2015
MSR Overview
SPECTRE MSR
Project Overview
Austin
Schedule
Austin
Manufacturing Status:
Hardware
Conrad
Manufacturing Status:
Software
Michael
Budget Status
Michael
Customer:
Advisor:
Dr. Keats Wilkie
Dr. Xinlin Li
NASA Langley
Department of Aerospace Engineering Sciences, CU
LASP
2
Heliogyro Background
•
Experimental onboard spacecraft
propulsion system
•
Uses high aspect ratio “blades” that
generate thrust from solar radiation
pressure
•
Blades are held in place by centripetal
acceleration of spinning spacecraft bus
•
Has advantages to traditional solar
sails
•
Blades can be pitched for more
complex maneuvering
•
No heavy support structures
necessary
3
Project Background
•
No heliogyro system has ever been
flown since first proposed in the
1970’s
•
NASA in interested in
demonstrating the first heliogyro
on a 6U CubeSat platform
•
SPECTRE is designing a control
system which will demonstrate
the ability to
 1) Pitch blades over a +/- 90
degree range relative to a
satellite bus
 2) Demonstrate the ability to
augment damping flapping and
pitching modes of the blade
Bus
2 Blade 6U CubeSat Design:
Dimensions 10cm x 20cm x 30cm
Housing
4
Blade Oscillations
Flapping
Blade Root
Blade Root
Twisting
Housing
θtwist
Deflected
Blade
Nominal
Blade
Blade Tip
Blade Root
θflap
Blade Tip
Blade Tip
5
6
FBD
Blade Housing
Legend:
CubeSat Bus
- Power
- Data
Actuator Drivers
- Commands
- Motion
Linear Motion
6V
Voltage 6 V
LED
Pitching Motion
Camera
Voltage
Rotational
Actuator
RS232
instructions
MatLab User
Interface
1.8 V
Angle,
Logic
(UART)
Mode, Angle, Rate (UART)
Images
9V
Gumstix
Blade
>1 V
Linear
Actuator
Arduino
Due
5V
Power
Supply
6V
7
Control Law block diagram
Θc
Transport
Delay
+
Derivative
control
Actuator Plant
Pendulum or
Membrane ladder
Plant
Tip Deflection
PDcontroller
Camera Resolution
Transport Delay
8
Control Law block diagram
Arduino Due/
User Interface
Θc
Transport
Delay
+
-
Motor Drivers
Derivative
control
Heliogyro Blade
Actuator Plant
Pendulum or
Membrane ladder
Plant
Tip Deflection
PDcontroller
Transport Delay
Image Processor
Camera Resolution/
Measurement Error
Sensor (Camera)
9
Control Law Expected Performance
Flapping Mode
Twisting Mode
Predicted Damping ratio:
Desired Damping Ratio:
0.0077
0.0073
Predicted Damping ratio:
Desired Damping Ratio:
0.0150
0.0136
10
Project Schedule
12
Spring Break
Controller Ready
to be Tested
Spring Break
All Machining
Complete
13
SPECTRE Schedule Summary
•
Team is currently 1-2 weeks ahead of schedule proposed at CDR
 Lead times shorter than anticipated for all parts
 Development of user interface started early
•
Fully testable blade controller expected before spring break
 Will provided approximately 3 weeks of margin for the project
•
Critical path of the project is now mainly dependent on software/electronics
 3 weeks allocated for final interfacing of all controller boards
14
Manufacturing Status:
Hardware
Design Modifications
 Increased
blade spool length, reduced mass
15 cm
Linear
Ball
Bearing
Sliding
Carriage
Previous Design
Carriage Guide
Smaller Diameter Rolled Blade
Camera
Smaller CubeSat Volume
1.550 kg
1.715 kg
8.6 cm
diameter
Linear Actuator
Linear Actuator
Shaft
Mounts
Larger Spool Length
17.5 cm
Blade Spool
9 cm
7.85 cm
diameter
8 cm
16
Parts Purchased
Rear View
Front View, Unspooled Blade
Part
Status
Expected
Delivery
Linear Motor
Driver
In-Route
Thursday 2/5
Rotary ServoMotor
In-Route
Thursday 2/5
Rotary Motor
Driver
In-Route
Thursday 2/5
Arduino
Obtained
Bevel Gear
Not Ordered
Turntable
Bearing
Obtained
Radial Bearing
Not Ordered
2-3 day
delivery
Linear-Servo
Motor
In-Route
Thursday 2/5
Linear Guide
Rails/Carriage
s
Obtained
Gumstix/Fire
Storm
Obtained
Camera
Obtained
2-3 day
delivery
Exploded Interface View,
Unspooled Blade
17
Manufactured Parts
Exploded Interface View,
Unspooled Blade
Part
Quantity
CubeSat Bus Walls
4
Rotary Motor Mount
1
Interface Walls
2
Interface Mount
1
Bevel Gear Modifications
1
Blade Housing Walls
4
Blade Spool Mounts
2
Camera Mount
1
Rear View
Bore Out 5/8” hole
Bevel Gear Modification
Front View, Unspooled Blade
18
Manufacturing Tasks
Part
Machine Completion
Progress
Estimated Time to
complete
Blade Housing walls
CNC, Knee
Mill
4/4
0 hours
Interface Walls
CNC, Knee
Mill
1/2
3 hours
CubeSat Bus Walls
CNC, Knee
Mill
0/4
8 hours
Blade Spool Mounts
Knee
Mill/Lathe
1/2
2 hours
Rotary Motor Mount
CNC, Knee
Mill
0/1
2 hours
Interface Mount
Knee
Mill/Lathe
1/1
0 hours
Bevel Gear Mods
Knee
Mill/Lathe
0/1
2 hours
Camera Mount
CNC
0/1
2 hours
Remaining Parts
Estimated Time to Completion
7/15
19 hours ~ 1 -2 weeks
19
Manufacturing Status:
Software/Electronics
Control Law/User Interface
Image Processing Algorithm
Camera Installation/Interface
Software Overview
21
Contol Software Overview
● User interface has been modified, the UI will use
MatLab instead of LabView. MatLab interface
much better with the Arduino Due
● The MatLab interface will recieve deflection angle
data from the image processor board
● If the control law is active, MatLab will apply a
derivative gain and send instructions to the divers
● The interface will also be able to send pitching
commands to the motor drivers
22
Arduino Interface Progress
Arduino-Matlab
Accessibility
Role in Control System
Connection through Arduino
Programming USB Port
Interface between Arduino and
MatLab
= Complete
Serial Communication (Read/Write)
via ASCII
Send/Receive Data from Image
Processor and Motor Drivers
= Supported, but
Identify/Test Digital I/O Pins
Provide Power to LEDs
Peripheral Read through SPI / I2C
Possibly needed for communication
with Image Processor
PWM / Motor Control
Possible method of commanding
actuators
not tested yet
23
Image Processing Algorithm
•
Input: raw, uncompressed YCbCr image file
•
Iterates through all pixels, applies a filter
highlights those that belong to the markers
•
Function finds the centroid of each marker
separately, uses both centroids to calculate
deflection angles
Critical Element
Status
Compiles in C++
Complete
Runs on test images
Complete
Runs with data from Image
Processing Camera
Incomplete (need to interface camera
with image processing board)
Calibrate filter thresholds
Incomplete (need test images from
camera)
24
Camera Interface Status
Wifi antenna
FirestormCOM-P
Summit
Expansion
Board
Caspa VL
25
Camera Interface Status
Image Capture  Started
•
Made bootable micro SD Card
•
Booted Firestorm with camera connected (power lights on everywhere)
•
Attempted image capture commands
-Failure to initiate image capture due to inability to parse pipeline links
-Additional failure to use gstreamer native image capture function
26
Camera Interface Work in Progress
Image Capture  Started
Board has been successfully booted with 2 different versions of the operating
system (embedded Linux), one older, one newer
•
Problem with newer version: Modules not inserted need to re-compile
kernel
•
Problem with older version: Unknown if support is built in for Wifi (needed
for installing necessary packages for Linux)
•
Currently working on installing the older modules manually with the
booting, downloading system (compiling kernel)
27
Image Processor Status Summary
Critical Element
Status
Image Processor Board Boots
Finished
Camera Connects, Receives Power
Finished
Camera Driver is Installed
In Progress
Images Captured
In Progress
USB Connection with Arduino
Not Started (Potentially more difficult
than camera interface)
28
Budget
Component:
Original Margin:
$2699.50
Shipping Costs were
originally included
in margin (~$300)
Number
Needed:
Lead Times
(Weeks):
Cost per
Component:
Total Price:
Overo Firestorm-P
1
3
$159.00
$ 159.00
Pinto
1
3
$ 27.50
$
27.50
Power Adapters
2
3
$ 10.00
$
20.00
Caspa VL
1
3
$ 75.00
$
75.00
Micro SD
1
0
$ 50.00
$
50.00
Arduino DUE
1
6-8
$ 50.00
$
50.00
USB Cable
3
0
$
3.00
$
9.00
Linear Motor
1
3
$690.00
$
690.00
Linear Motor Driver
1
8
$226.00
$
226.00
Rotary Motor
1
3
$220.00
$
220.00
Rotary Motor Driver
1
6-8
$226.00
$
226.00
LEDs
2
0
$ 10.00
$
10.00
Aluminum Sheet
1
1
$ 50.00
$
50.00
Misc. Wires
?
0
$100.00
$
100.00
Misc. Screws
?
0
$100.00
$
100.00
Rotary Encoder
1
3
$ 50.00
$
50.00
Hardened Steel Shaft
1
1
$ 24.00
$
24.00
Linear Bearing with
Pillow Block
1
1
$
40.00
$
40.00
Shaft Support
2
1
$
44.00
$
44.00
Bevel Gear
1
1
$
50.00
$
50.00
Turntable Bearing
1
1
$
5.00
$
5.00
Radial Berings
1
1
$
5.00
$
5.00
Precision Shaft (hollow)
1
1
$
40.00
$
40.00
Mounting Components
1
1
$
40.00
$
40.00
TOTAL
$ 2300.50
30
Component:
Number
Needed:
Lead Times
(Weeks):
Cost per
Component:
Total Price:
Overo Firestorm-P
1
3
$159.00
$ 159.00
Pinto
1
3
$ 27.50
$
27.50
Power Adapters
2
3
$ 10.00
$
20.00
Caspa VL
1
3
$ 75.00
$
75.00
Micro SD
1
0
$ 50.00
$
50.00
Arduino DUE
1
6-8
$ 50.00
$
50.00
USB Cable
3
0
$
3.00
$
9.00
Linear Motor
1
3
$690.00
$
690.00
Linear Motor Driver
1
8
$226.00
$
226.00
Rotary Motor
1
3
$220.00
$
220.00
Rotary Motor Driver
1
6-8
$226.00
$
226.00
LEDs
2
0
$ 10.00
$
10.00
Estimated Margin
$2410.38
Aluminum Sheet
1
1
$ 50.00
$
50.00
Misc. Wires
?
0
$100.00
$
100.00
Misc. Screws
?
0
$100.00
$
100.00
Margin is sufficient to
repurchase any
component multiple
time if necessary
Rotary Encoder
1
3
$ 50.00
$
50.00
Hardened Steel Shaft
1
1
$ 24.00
$
24.00
Linear Bearing with
Pillow Block
1
1
$
40.00
$
40.00
Shaft Support
2
1
$
44.00
$
44.00
Bevel Gear
1
1
$
50.00
$
50.00
Turntable Bearing
1
1
$
5.00
$
5.00
Radial Berings
1
1
$
5.00
$
5.00
Precision Shaft (hollow)
1
1
$
40.00
$
40.00
Mounting Components
1
1
$
40.00
$
40.00
Current Expenditures
$2320.62
Estimated Final
Expenditures
$2589.62
TOTAL
$ 269.00
31
Backup Slides
Critical Project Elements
• Blade is kept in a housing that can
accommodate a spooled blade of 500+
meters in length
• Blade housing has 1.4U volume, electronics
require 0.4U in CubeSat bus
• Total of 1.8U
• System requires 20 W
• Total mass of a single blade+housing
assembly ~1 kg.
33
SPECTRE Work Plan Fall 2014
Spring Break
Manufacturing
Software
Mechanical
Electrical
Systems
Classes
MSR
TRR
Spring Final
34
Blade Controller Requirements
Controller housing must be able to accommodate one blade capable of providing the
spacecraft with a 0.1 mm/s^2 acceleration
Controller must be able to pitch blades to ± 90° with ± 5° of accuracy
Controller must demonstrate a damping ratios for flapping and twisting modes of
𝜻𝒇𝒍𝒂𝒑 = 0.0073 𝜻𝒕𝒘𝒊𝒔𝒕 = 0.0136
Controller must be capable of sensing blade deflections without an ambient light source
Controller and blade occupy 2U of volume (10cm x 10cm x 20cm)
Controller must run on approximately 5 watts of power
Controller must conform to Cubesat weight requirement ~1.3 kg/U, total of 2.6 kg
35
Camera Interface Status
Image Capture  Started
•
Tried using old u-boot image, kernel 2.6.34 instead of current 3.5.7, but it
wouldn’t boot
•
Tried installing modules from 2.6.34, but it wouldn’t boot
•
Tried again with installing the modules, but it wouldn’t allow downloads
(tried again, but it wouldn’t boot)
•
Currently working on installing the 2.6.34 modules manually with the
booting, downloading system (compiling kernel)
36
Justin Slides
Control Law implementation
Θc
+
-
Transport
Delay
Derivative
control
•Receive the Data on
tip deflection from the
Camera
•Calculate the rate the
tip is deflecting
•Implement a
derivative gain
•Export the moment
need to damp the solar
sail blade to the motors
Actuator
Plant
PD-controller
Transport
Delay
Pendulum or
Membrane
ladder Plant
Tip
Deflection
Change
resolution of
cameras
38
Control Law implementation
Θc
+
-
Transport
Delay
Derivative
control
Actuator
Plant
PD-controller
Transport
Delay
Pendulum or
Membrane ladder
Plant
Tip
Deflection
Change
resolution of
cameras
39
Camera implementation
Θc
θc=0
+
-
Transport
Delay
Derivative
control
Actuator
Plant
PD-controller
Transport
Delay
Pendulum or
Membrane
ladder Plant
Change
resolution of
cameras
Tip
Deflection
•Calculate the tip deflection in
degrees
•Transport Delay is placed in
model to compensate for
computational delays
•Send Tip deflection to the control
law
40
Camera implementation
Θc
θc=0
+
-
Transport
Delay
Derivative
control
Actuator
Plant
PD-controller
Transport
Delay
Pendulum or
Membrane
ladder Plant
Tip
Deflection
Change
resolution of
cameras
41
Work Still Left to be done: Actuators
Θc
+
-
Transport
Delay
Derivative
control
Actuator
Plant
PD-controller
Transport
Delay
Pendulum or
Membrane
ladder Plant
Tip
Deflection
Change
resolution of
cameras
• Actuators will receive the desired movement to
create a moment
• Output the desired moment onto the solar sail to
damp the blade
42