Auburn University
Project “Wall-Eagle”
PDR
Rocket Design
Rocket Model
Detailed Sections
Mass Estimates
Section
Structure
Supporting Equipment
Electronics
Recovery
Motor
Total
Mass Growth
Mass Allowance
Mass (lb.)
8.577
9.444
1.5
2.516
6.47
28.5
3.7
32.2
Percentage of Total Weight
33.58%
31.47%
5.00%
8.39%
21.56%
N/A
12.98%
113%
Ogive Nose Cone
•
•
•
•
Low Coefficient of Drag
Easy to manufacture
Rated highest by team trade study
Commonly used in professional and hobby
rocketry
Nose Cones
Type of Cone
Coefficient Of Mass
Drag
Ease of
Manufacturing
Total
Ogive
3
2
2
7
Haack
3
2
1
6
Ellipsoid
1
1
2
4
Conical
1
3
3
7
Trapezoidal Fin
• Very easy to manufacture
• Less drag than clipped delta fins, more than
elliptical fins
• Quicker stabilization than elliptical fins and
clipped delta fins.
Fins
Type of Fin
Stability
Ease of
Drag
manufacturing
Total
Trapezoidal
10
10
8
28
Clipped Delta
8
10
7
25
Elliptical
7
7
10
24
Motor Selection
Motor Selection / Altitude Prediction
• Initial Motor selection is the Aero K780R-P
▫ R-P: Redline, Plugged
• Initial thrust-to-weight ratio above required 5:1
• Achieves above average thrust within ¼ second
• High initial thrust provides high stability off the
rail
K780R-P Thrust curve
Motor Selection/Altitude Prediction
• Maximum altitude achieved 3395 feet
• Mass increase of 12.97% altitude gives a
projected 3045 feet
• Assumptions include smooth construction and
5 mph winds
• Mass increase of 25% would not allow rocket to
reach desired altitude
K780R-P Altitude vs. Time
Figure 1.3: Altitude vs. Time K780R-P
3500
3000
Altitude (feet)
2500
2000
1500
1000
500
0
0
-500
10
20
30
40
50
Time (seconds)
60
70
80
90
100
K780R-P Motor Specifications
Manufacturer
AeroTech
Motor Designation
K780R-P
Diameter
75 mm
Length
15.5 inches
Impulse
2371 N-sec
Total Motor Weight
5.95 lbm
Propellant Weight
2.8 lbm
Propellant Type
Redline
Average Thrust
175 Pounds
Maximum Thrust
216 Pounds
Burn Time
3.0 sec
Secondary Motor
• Secondary motor is the CTI L-610
• Mass increase of 25% altitude simulated 3245
feet
• Increased mass would utilize ballast tank
• Would require an increased fin size for
maintaining stability
Cesaroni L-610 Motor Specifications
Manufacturer
Cesaroni Technologies Incorporated
Motor Designation
L-610
Diameter
75 mm
Length
15.5 inches
Impulse
3130.9 N-sec
Total Motor Weight
8.71 lbm
Propellant Weight
3.5 lbm
Propellant Type
Redline
Average Thrust
137 Pounds
Maximum Thrust
197 Pounds
Burn Time
5.1 Seconds
Recovery
Overview
Parachutes
• Three parachutes required
▫ Drogue – 20 inches*
▫ Main – 140 inches*
▫ Payload – 36 inches*
* Estimates using standard round parachute without
spillholes.
Parachutes
• Construction
▫ Shape
 Semi-ellipsoidal
 No spill hole
Electronics
• Avionics bay
▫ Two altimeters
 Altus Metrum Telemetrum
 PerfectFlite StratoLogger
Attachments
• Fasteners
▫ Nylon Slotted Pan Head Machine Screws
▫ Steel U-Bolts
▫ Quick Links
Parachute Materials
• The parachute will be made of Ripstop nylon
• Ripstop’s tear resistant weaving is ideal for
parachute making
Shock Cord Material
• The shock cord will be made of
1” tubular nylon
• 1” tubular nylon has excellent
tensile properties
• A vendor has already been
secured
• The Auburn team has worked
with this material before
CO2 Ejection System
• Increased safety
• More reliable at high altitudes
• Reduced risk of equipment damage
Commercial Systems
• Available from Rouse Tech
and Tinder rocketry
• Viability of CO2 systems
repeatedly demonstrated in
the field
• A single 12g cartridge is
recommended for a 5”
diameter rocket with sections
up to 22” long.
Custom Designed System
• E-match ignites small Pyrodex
charge
• Charge pushes cartridge
against spring into an opening
pin
• Cartridge is punctured and
quickly releases CO2
• Section is pressurized with
enough force to separate
rocket and deploy parachutes
Custom Designed System
• Each system contains three
CO2 cartridges
• Each cartridge is separately
controlled
• Dual fault tolerance
Ejection System Implementation
•
•
•
•
Two ejection systems total mounted outside the avionics bay
One system deploys drogue parachute and ejects payload bay
Second system deploys main parachute
Two altimeters, each controls two CO2 cartridges on each
system
Autonomous Ground Support
Equipment – Project WALL-Eagle
Overall AGSE Concept
Overall AGSE Concept
AGSE Payload Hatch
Payload Hatch Function
• Seals payload bay during flight
• Hatch opens and closes
autonomously with a
microservo
• Guides robotic arm into
payload bay
Payload Access Plate and Positioning
• Single access plate revolves on
hinge
• Hinge operates with
microservo
• Will allow remote opening and
closing
• Optical markers to guide
robotic arm
Payload Access Plate and Positioning
• Single access plate revolves on
hinge
• Hinge operates with
microservo
• Will allow remote opening and
closing
• Optical markers to guide
robotic arm
Payload Hatch Animation
AGSE Payload Capture &
Transport
Robot Arm Capabilities
• Needs at least 4 degrees of freedom
• Controlled by central master-controller
• Detect Payload via IR sensors
▫ Backup: Navigate to predetermined location
• Be able to lift 4 oz. payload
• Navigate over payload and rocket hatch
Fabricated vs. Purchased
Fabrication Advantages:
▫ Customizable for any purpose
▫ Cost-effective
▫ Deep subsystem educational
merit
▫ Unique and original
▫ High scientific merit
Purchase Advantages
▫ Commit team-member time
elsewhere
▫ High-performance
▫ Reduce risk of subsystem
failure
▫ Compensate for lack of teammember experience
▫ Customizable parts
▫ High scientific merit
Decision: Purchase Robot Arm
• Chose to purchase commercially available arm.
• High performance, legacy, and affordability
warrant purchase of arm.
• Arm like Lynxmotion AL5B or AL5D possible
choices.
CrustCrawler AX-12A Smart Robotic Arm
• ~22” maximum reach
• 5-6 degrees of freedom
• Most value and capabilities
for the price
• Completely customizable
• Price - $830
CrustCrawler AX-12A Key Features
•
1mbs serial communication protocol
 Dual actuator design in the shoulder and wrist axis for maximum lifting
capability (2 to 3 pound (.907kg to 1.36kg)
 Fully ROS,MATLAB,LABVIEW Compatible!
•
•
Rugged, all aluminum construction for maximum kinematic accuracy (1mm - 3mm)
Hard Anodized finish for maximum scratch and corrosion resistance
 Compatible with ANY micro-controller/computer control system /
programming Language (Open Source!)
 The only robotic arms that feature feedback for position, voltage, current and
temperature
•
Smooth, sealed, self lubricating ball bearing turntable
•
•
(3) integrated mounting tabs for easy mounting to a fixed or mobile base
(5) Gripper options to choose from
 Fully adjustable initial base angle
 Full control over position (300 degrees), speed, and torque in 1024 increments
• Automatic shutdown based on voltage or temperature with status indicator LED
 Sensor engineered gripper design accepts, pressure sensors, IR detectors, CCD
cameras and more!
Robot Arm Gripper Requirements
•
•
•
•
•
•
Able to hold cylindrical payload
Support 4 oz. weight
Reach ground/reach payload bay
Able to rotate at the wrist
Able to sense that payload has been obtained
The Big Grip Kit from the CrustCrawler AX-12A series
robotic arms meet criteria plus more
IR Sensors
• Affixed to front of grabber, scans dark ground
(grass/dirt) for light surface (payload).
• Arm engages payload once detected.
• If payload dropped, search and capture of the
payload may be repeated until mission success
Contingency: Preprogrammed Location
• Use preprogrammed location of payload in case
IR sensors plan doesn’t work out
• Can choose location of payload, so static
coordinates suffice
• Easier, but will cause launch failure if payload
dropped
AGSE Launch Rail and Truss
AGSE Truss
• Constructed out of durable
carbon fiber
• Designed to support the full
weight of the rocket
• Connected to two electric gear
motors
• Rotates from horizontal to 85°
• Returns to horizontal after
rocket launch
AGSE Truss
• Bottom is counterweighted to
ease lifting
• Measurements ensure bottom
does not contact the ground
• Rocket attached to truss via
slotted rails
• Attachment rails double as
launch rails ensuring launch
stability
• Truss will lock in vertical
position once erect
AGSE Truss
• In launch position, blast shield
protects sensitive components
• Igniter insertion system
extends into motor
• Rocket is then ready for
inspection
• Once inspected, rocket is ready
for launch
AGSE Igniter Insertion System
Igniter Insertion System
• Toothed insertion
system
• DC electric motor drives
the tooth extender into
the mast
• Initiated with a program
that is linked to the
AGSE controller
Igniter Insertion System
• Located 6-8 inches
below the base of
the rocket.
• Main motor is
protected by the
blast plate
• Rise through a
whole in the blast
plate to access the
rocket
Igniter Insertion System
• Extension of 21 inches
• Igniter pause at full
extension
• E-match attached to tip
of the insertion system
is in contact with motor
• Inspection and arming
of the rocket
• Countdown ensues,
followed by blast off
Igniter Inserter System
Master Microcontroller and Full
System Operation
Master Microcontroller
• Single microcontroller drives
all AGSE functions
▫ Simplifies design
▫ Minimizes risk
▫ Eliminates communication
between multiple
microcontrollers
• Arduino mega or comparable
device used
Subsystem Connectivity
• All autonomous
systems connected
through
microcontroller
▫ Only launch
controller handled
independently
• Single start, pause,
and reset switches
Nominal AGSE Process
• Start command received
• Robotic arms commanded to
find payload
• Arm deposits payload in rocket
• Payload bay hatch closes
• Launch rail raised
• Igniter inserted
• Sequence pauses
• Launch button depressed
• Rocket launches
AGSE Flow Chart
• System inspected prior to
launch
• In some cases it is possible to
reset and re-run sequence in
an error has occurred
Risks
•
•
•
•
Power Failure
Programming Errors
Equipment Assembly Errors
Component Synchronization
Failure
• Sequence exceeds allotted time
(10 minutes)
• System unresponsive
• Damage from environment
(humidity, rain)
Test Plans
• Full system test (normal
conditions)
• Off-design rocket mass
• Off-design payload
configuration
• Partially drained batteries
• Power failure during AGSE
sequence
• Dropped payload
Safety Section
Construction Safety Techniques
• All members sign a form for their understanding
of lab safety practices
• Proper personal protective equipment will be
easily accessible and in good condition
• Proper hazardous material disposal units will be
easily accessible
• Proper safety equipment is in place in all labs
Testing Safety Techniques
• Proper protective systems will be in use during
testing practices
• Safe testing guidelines will be posted in the
testing facilities
• Testing equipment will have sign-out sheets
• Testing checklist will be proactively filled out
Operations Safety Techniques
• Safe range practices will be strictly enforced
• Checklists for transport, assembly, and launch
procedures will be completed
• Locations for safe observation of Auburn
launches will be marked off
• Personnel will be properly trained for launch
and recovery procedures
Incident Safety
• Standard operating guidelines are in place for
different emergencies with easy access
• Material Safety Data Sheets will be posted in all
facilities
• Proper precautions will be taken to ensure a safe
working environment
• Emergency incident operations will be required
training for all organizational personnel
Educational Outreach
7th Grade Rocket Week
Students Learn About:
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•
•
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Gravity and g-forces
Newton’s Laws of Motion
Elementary rocketry
Science, technology,
engineering, and mathematics
• Teamwork and communication
7th Grade Rocket Week
Students Work Hands-On:
• Assembling an Alpha rocket in
teams of 2-3
• Sanding, gluing, and painting
rockets
• Initiating and observing rocket
launches
Educational Outreach Programs
• Auburn Junior High School/Auburn High School Rocket Team
▫ Mentor team to compete in Team America Rocketry Challenge
▫ Teach students design and technical writing methods
▫ Provide facilities and equipment for team use
• Boy Scout Merit Badge University
▫ Teach troops about space exploration
▫ Supervise Alpha rocket assembly
▫ Award Space Exploration Merit Badge
Educational Outreach Programs
• Tuskegee Airmen National Historic Site Field Trip
▫ Guide Drake Middle School students on half-day field trip
• Samuel Ginn College of Engineering E-Day
▫ Present AURA and Student Launch teams to prospective students
• AURA Movie Night Event
▫ Show Apollo 13 at Tiger 13 Cinemas
▫ Provide Q&A with engineers and students
Additional Information
• Budget Summary
• Timeline Summary
Questions