Auburn University Project WallEagle PDR Rocket Design Rocket
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 K 780 R-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
K 780 R-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
K 780 R-P Altitude vs. Time Figure 1. 3: Altitude vs. Time K 780 R-P 3500 3000 Altitude (feet) 2500 2000 1500 1000 500 0 0 10 20 30 40 50 Time (seconds) 60 70 80 90 100
K 780 R-P Motor Specifications Manufacturer Aero. Tech Motor Designation K 780 R-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 �Perfect. Flite Strato. Logger
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
CO 2 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 CO 2 systems repeatedly demonstrated in the field • A single 12 g 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 CO 2 • Section is pressurized with enough force to separate rocket and deploy parachutes
Custom Designed System • Each system contains three CO 2 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 CO 2 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 AL 5 B or AL 5 D possible choices.
Crust. Crawler AX-12 A Smart Robotic Arm • ~22” maximum reach • 5 -6 degrees of freedom • Most value and capabilities for the price • Completely customizable • Price - $830
Crust. Crawler AX-12 A Key Features • 1 mbs serial communication protocol ü Dual actuator design in the shoulder and wrist axis for maximum lifting capability (2 to 3 pound (. 907 kg to 1. 36 kg) ü Fully ROS, MATLAB, LABVIEW Compatible! • • Rugged, all aluminum construction for maximum kinematic accuracy (1 mm - 3 mm) Hard Anodized finish for maximum scratch and corrosion resistance ü Compatible with ANY micro-controller/computer control system / programming Language (Open Source!) ü 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 ü Fully adjustable initial base angle ü Full control over position (300 degrees), speed, and torque in 1024 increments • Automatic shutdown based on voltage or temperature with status indicator LED ü 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 Crust. Crawler AX-12 A 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
7 th Grade Rocket Week Students Learn About: • • Gravity and g-forces Newton’s Laws of Motion Elementary rocketry Science, technology, engineering, and mathematics • Teamwork and communication
7 th 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
- Slides: 75