Auburn University Project Wall-Eagle FRR
Rocket Design
Rocket Model
Mass Estimates Booster Section Mass(lb.) Estimated Upper Section Mass(lb.) Actual Component Mass(lb.) Estimated Mass(lb.) Actual Component Structure 3.21 2.119 Structure 3.83 1.625 Ballast Tank 2.754 1.23 Payload Bay 3.07 1.5 Bulkhead 0.233.119 Avionics Bay 2.754 1.25 Engine Block 0.315.687 Recovery 0.296 1.824 Centering Ring 0.318 0.237 Nose Cone 2.13 2.5 Fins 0.907 1.199 Electronics 1.4 0.523 Recovery 2.22 1.708 Motor block 0.686 Motor 3.85 3.85 Electronics 0.1 Total 16.527 Total 13.48 9.908
Ogive Nose Cone Low Coefficient of Drag Easy to manufacture Rated highest by team trade study Commonly used in professional and hobby rocketry
Nose cone dimensions
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.
Fin Dimensions
Internal bays Payload Bay Ballast Tank Avionics Bay Motor Section
Stability Center of Gravity: 49.22 inches from nose tip Center of Pressure: 61.26 inches from nose tip Stability: 2.29 calibers Calculations given from OpenRocket Mass additions are expected to be added forward of CG
Stability margin before apogee 3.5 3 2.5 Stability Caliber 2 1.5 1 0.5 0 0 2 4 6 8 10 12 14 16 Time (seconds)
Testing Material testing for: Carbon Fiber ABS Plastic Ground testing Co2 system Igniter AGSE clearance Wind Tunnel Payload bay door Parachutes
Motor Selection
Motor Selection / Altitude Prediction Initial Motor selection is the Aero K960-P R-P: Loki White, 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 Rail exit velocity is 75 ft/s
K960-P Thrust curve
Thrust-to-weight 16 14 Thrust-to-weight ratio 12 10 8 6 4 2 0 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 Time Seconds
Altitude Predictions At 5 Mph winds expected altitude of 2958 ft At 10 Mph winds expected altitude of 2927ft At 15 Mph winds expected altitude of 2898ft At 20 Mph winds expected altitude of 2885ft Mass can easily be removed from ballast Kinetic Energy at main deploy is 23373 lb-ft Kinetic energy upon landing is 5511 lb-ft
K960-P Altitude vs. Time Figure 1.3: Altitude vs. Time K780R-P
K960-P Motor Specifications Manufacturer Motor Designation Diameter Length Impulse Total Motor Weight Loki Research K960-P 2.13 inches 19.6 inches 1949 N-sec 3.85 lbm Propellant Weight Propellant Type Average Thrust Maximum Thrust Burn Time 2.05 lbm Loki White 225 Pounds 345 Pounds 1.95 sec
Full-Scale Flight Results 3000 2500 2000 Altitude (feet) 1500 Actual Data Modeled Data 1000 500 0 0 5 10 15 20 25 Time (Seconds)
Full-Scale Successes and Failures Modeling Predictions Highly Accurate Predicted 2487, Actual - 2511 Stability Very Stable Recovery Main deploy failure, but CO2 Ejection System Overall Success
Recovery
Overview
Parachutes Drogue 22 inches Deploys at apogee Slows rocket components to safe speed for main deploy Main 99 inches Recovers booster section and avionics bay Payload 65 inches Deploys simultaneously with main Recovers payload bay and attached nose cone
Parachutes Construction Shape Semi-ellipsoidal No spill hole
Electronics Redundant altimeters Altus Metrum Telemetrum PerfectFlite StratoLogger RF trackers ZigBee mini GPS
Attachments Fasteners Nylon Slotted Pan Head Machine Screws Steel U-Bolts Quick Links
Materials Parachutes are made in-house from rip-stop nylon Shroud lines for main and payload parachutes made from ½ inch tubular nylon Shroud line for drogue parachute made from paracord Shock cords made from 1 inch tubular nylon
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 12g cartridge is recommended for a 5 diameter rocket with sections up to 22 long.
Custom Designed System E-match ignites small black powder 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
Ejection System Implementation Two ejection systems total mounted outside the avionics bay One ejection system deploys drogue parachute Second system deploys main parachute and ejects payload bay Each altimeter controls all charges on both ejection systems
Drift Calculations Section Weight (lbs.) Parachute Size (ft.) 5 mph 10 mph 15 mph 20 mph Booster section and avionics bay (main parachute) Payload bay and nose cone (payload parachute) 14.3 lbs. 8.25 ft. 1096 ft. 1228 ft. 1315 ft. 1476 ft. 4.9 lbs. 5.42 ft. 874 ft. 973 ft. 1038 ft. 1159 ft.
Autonomous Ground Support Equipment Project WALL-Eagle
Overall Final Design
AGSE Design Overview
AGSE Payload Bay and Hatch
Payload Hatch Function
Payload Access Plate and Positioning
Payload Bay Drawing
Payload Retrieval System (PRS)
Modified CrustCrawler AX-12A Smart Robotic Arm ~29 maximum reach (nearly 7-inch extension) 5 degrees of freedom Most value and capabilities for the price Completely customizable Price - $830 Infrared sensors installed Modified gripper
Robot Arm Dimensions
Robot Arm Gripper
Modified Robot Arm
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
IR Sensors Payload Detection and Orientation
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
Launch Vehicle Elevation System (LVE)
LVE Drawing
LVE Drawing
LVE LT 2000 Winch
Elevation Sequence Measurements ensure bottom does not contact the ground Rocket attached to truss via slotted launch rail Truss will be cued to stop via pressure switch Truss will lock in vertical position once erect via winch system and blast plate Expected to take approximate 60 seconds or less
Launch Vehicle Elevation System In launch position, blast shield protects sensitive components Igniter insertion system extends into motor Rocket is then ready for inspection
Automated Charge Insertion System (ACI)
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 26.6 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 Dowel diameter will not choke motor
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 used
Electrical Schematic for AGSE
Launch Controller
Subsystem Connectivity All autonomous systems connected through microcontroller Only launch controller handled independently Single start, pause, and reset switches
Systems Sequence Test
Requirements and Verification AGSE Objectives System The entire system must secure the payload inside the rocket and have the rocket ready to launch in under 10 minutes. Launch Vehicle Elevation System (LVE) Launch pad will support the entire weight of the AGSE and rocket. House and protect important electronics and motors. Raise rocket from horizontal to launch position 5 degrees from the vertical. Support and guide rocket during launch to allow stable flight. Capable of lifting launch vehicle weighing 30 lbs. Payload Retrieval System (PRS) Scan and detect payload location on ground. Capture the payload. Deliver the payload to the payload bay in the launch vehicle. Return to resting position. Must be able to reacquire payload if dropped by the arm. Automated Charge Insertion System (ACI) Must move the igniter into the motor once rocket is in launch position. Must move the igniter into the motor until it reaches the top of the fuel grain. Will stop moving the igniter once it reaches top of fuel grain. Must withstand exhaust from launch vehicle. Must be reusable.
Project Management
Budget / Funding Summarized Budget Recovery $1,139.18 Subscale $344.04 Full-Scale $1,212.00 Manufacturing $1,314.77 Travel $3,339.00 Educational Outreach $2,572.00 AGSE $1,847.00 Project Management $2,880.00 Overall Total $14,647.99 System Price On the Pad (Summarized) Recovery $1,139.18 Full-Scale $1,212.00 Manufacturing $1,314.77 AGSE $1,847.00 Overall System on the Pad $5,512.95
Timeline