PLAID: Precision Launch and Autonomous IDentification NASA USLI - - PowerPoint PPT Presentation

PLAID: Precision Launch and Autonomous IDentification

NASA USLI Critical Design Review Carnegie Mellon Rocket Command

January 24, 2018

Launch Vehicle Design

Overall Design

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Overall Design

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Main Dimensions & Materials

Component Dimensions Material Lower Airframe 4” D x 32” L Fiberglass (G-12) Avionics Bay (coupler) 4" D x 12" L Fiberglass (G-12) Avionics Bay (switch band) 4" D x 2.75" L Fiberglass (G-12) Middle Airframe 4" D x 16" Fiberglass (G-12) Recovery Bay (coupler) 4” D x 11” L Fiberglass (G-12) Recovery Bay (switch band) 4” D x 2” L Fiberglass (G-12) Upper Airframe 4” D x 24” L Fiberglass (G-12) Nose cone 4” D 5/1(L/D) Fiberglass (G-12) with Aluminum tip Motor Mount 75mm Fiberglass (G-12) Fins 3/16” thick Fiberglass (G-10)

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Total Rocket 4" D x 98.2” L (OpenRocket)

Nose Cone

• 4" 5-1 Von Karman
• Polished to reduce surface drag
• Optimized shape for operating velocity

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Nose Cone Shape Drag Coefficient at Mach 0.3 Drag Coefficient at Mach 0.5 Drag Coefficient at Mach 0.8 Cone 0.06 0.07 0.10 Von Karman 0.04 0.04 0.03 Parabolic 0.04 0.04 0.03 Ellipsoid 0.06 0.06 0.07 Tangent ogive 0.04 0.04 0.03 Power series 0.04 0.04 0.03

Fins

• Upper Fin Aspect Ratio:

0.929

• Lower Fin Aspect Ratio: 1.23
• G10 Fiberglass
• Beveled
• Maximum flutter boundary

speed: 1452.14 mph

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Upper Fin CAD Model Lower Fin CAD Model

Motor Retention Method

• 6160-T6 Aluminum
• Thrust Plate, 75mm flanged motor retainer, 54/75mm motor adapter
• 18-8 Mounting Hardware

Simulation Results

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Motor Retainer Base​ Thrust Plate​

• Under Maximum Thrust from Motor​
• Maximum Displacement​
• 4.902e-4 in​
• Minimum Factor of Safety​
• 2.8​
• Under Maximum thrust from Motor​
• Maximum Displacement​
• 1.173e-4​
• Minimum Factor of Safety​
• 31​

Mass and Flight Stability

Statement and Margin

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Mass (lb) Estimated Margin of Error (lb) Center of Gravity, CG (in. from forward end) Center of Pressure, CP (in. from forward end) Static Stability Margin (cal) Dry 19.38 ±2 55.849 77.541 5.34 Wet (with current chosen motor) 25.4 ±2.5 61.429 77.541 3.95

Static Margin Diagrams

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Motor Selection

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1. The motor must be reloadable. 2. It must be manufactured by Aerotech, CTI, or Loki. 3. The output apogee must be within a range of 5,500 to 7,000 ft. 4. The motor thrust curve must feature a neutral-regressive burn profile with a high initial thrust peak. 5. The ballast required to lower the apogee under ideal (no wind) conditions must not exceed 10% of the total design weight (motor included). 6. Must provide a rail-exit velocity of 52 fps or above. 7. Must be in-stock at more than two online suppliers.

Motor Selection Criteria

Final Motor Selection

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• Changed from CTI K650SS to CTI K711
• Total impulse: 2374 N-s (533.7 lbf-s)
• Estimated ballast: 2.26 lbs (8.93% of wet weight)
• Apogee: 6003 ft
• Off-rail velocity: 74.4 fps
• Wet weight: 4.846 lbs
• Dry weight: 1.76 lbs

Criteria Met? Reloadable Yes Aerotech, CTI, or Loki Yes Apogee within 5500-7000 ft Yes Neutral-regressive burn profile with high initial thrust peak Yes Ballast under 10% of wet weight Yes Rail-exit velocity 52 fps or above Yes In stock at more than two online suppliers Yes

Launch Parameters

Thrust-to-Weight Ratio

• Lift-off thrust:
• 1702.77 N
• PLAID Weight:
• 112.54 N
• Thrust-to-Weight Ratio
• 15:1
• More than sufficient thrust.

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Rail Exit Velocity

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• Minimum Required Velocity
• 52 ft/s
• Achieved Velocity
• 74.1 ft/s
• Reduces weathercocking

Recovery

Recovery Characteristics

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Parameter Drogue Main Type SkyAngle 20 inch Rocketman 12 foot Harness Material Nylon Nylon Harness Length (ft) 20 20 Harness Thickness (in) 1 1 Terminal Velocity (ft/s) 103 14.4

Kinetic Energy

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Section Drogue Kinetic Energy (ft-lbs) Landing Kinetic Energy (ft-lbs) Nose Cone 355.6 6.95 Upper Airframe 883.5 17.27 Lower Airframe 2396.9 46.85 Total 3636 71.07

• Landing Kinetic Energy is below 75 ft-lb threshold

Chosen Parachutes

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Rocketman 12' Parachute SkyAngle 20" Drogue Parachute

Predicted Drift

Wind Speed (mph) Drift Speed (ft/sec) Drift Distance (ft) 20 29.33 2354 15 22 1766 10 14.67 1177 5 7.33 588

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Recovery E-Bay Components

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3D printed altimeter sled Black Powder Canisters (4) Coupler (OD=3.896") Double-plated Bulk plates (2) Threaded Rods (2) Eyebolts (2) Nuts (lock and jam) PerfectFlite Stratologger Altimeters (2) Schurter Rotary Switch (2) 9V Battery (2)

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Recovery System Summary

Choosing a GPS and TX unit

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Data logging capabilities Power source Transmission range Transmission frequency Eggfinder GPS tracking system Not included, but is capable

• f accepting

OpenLog data logger External 2S LiPo with 250 mAH capacity Up to 10,000 feet 900 mHz license-free Beeline 100 mW GPS system Included with

• nboard non-

volatile memory External 2S LiPo with 250 mAH capacity Over 40 miles Any frequency in 70 cm band in 125 Hz steps (radio license required)

Final GPS and TX Unit

• Eggfinder GPS Tracking System
• 2S 300mA 7.4V LiPo Battery
• Soldering required to assemble GPS
• Equipment available at Makerspace

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GPS Housing and Location

• 3D Printed ABS Housing
• GPS and battery strapped into

place on inner sled

• Outer shell screwed into the

inner sled

• Tied to upper airframe shock

cord using eye bolt

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Test Plans and Procedures

Summary of Tests

Test Objective Payload Testing Validate the integrity of TDS Launch Vehicle Drop Test Determine whether all sections of PLAID can withstand landing forces PLAID Ejection Charge Test Determine whether the ejection charges calculated are enough to break the shear pins and deploy the parachutes Launch Prep Test Determine whether PLAID can be prepared for launch in under three hours Launch Pad Mock Test Determine whether PLAID’s batteries can keep the altimeters and avionics bay ready to launch for one hour Launch Pad Test To determine whether PLAID can remain in a launch ready configuration for one hour. DIET PLAID Ejection Charge Test Determine whether the ejection charges calculated are enough to break the shear pins and deploy the parachutes. G12 Materials Testing Determine the elastic modulus and compressive strength of G12

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Example Payload Testing

• Objective to determine the following:
• Can the TDS detect the targets
• Amount of time required
• Frequency of errors
• Methodology
• Supply video with different orientations of

targets

• Supply previous rocketry footage
• Supply video from full scale rocket flight
• Success Criteria
• Detecting targets before apogee with 95%

accuracy

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Example: Ejection Charge Test

• Success Criteria
• The shear pins are broken and the sections come apart.
• Methodology
• Find clear surface in a large outdoor field
• One ejection charge loaded
• Launch vehicle is positioned slightly above horizontal
• Manually trigger charge with voltage
• Examine shear pins to confirm break
• Ensure separation of sections
• Adjust ejection charge until successful
• Successful pass on DIET PLAID Launch Day
• Small failure of ejection charge during second launch
• Adding buffer

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Example: G12 Fiberglass Materials Testing

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• Instron 4469 universal

testing machine

• Sample from Wildman

Rocketry

• Tensile testing necessary

Material Characteristic Value Elastic Modulus 905700 psi Compressive Strength 46000 psi

Scale Model (DIET PLAID) Flight Test

DIET PLAID Launch Day

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DIET PLAID Launch Day

• Conditions
• Minimum Temperature: 23°F
• Maximum Temperature: 45°F
• Humidity: 59%
• Wind Speed: 3 mph

January 24, 2018 35 Launch Motor Time to Apogee (sec) Flight Time (sec) Apogee (ft) Actual Apogee (ft) 1 Aerotech H115DM 9.66 43.6 1354 1322 2 CTI H170 11 43.1 1915 1670 3 CTI H410 8.99 43.2 1331 1307

DIET PLAID Flight Data

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Unsuccessful Successful

DIET PLAID Influence on PLAID

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• Unsuccessful Trial
• Main Parachute did not deploy
• Too Little Black Powder
• Almost Broke Shear Pins
• For Full Scale
• Make Calculations for needed black powder for a certain force on the

chamber

• Add 80 lbs to add a factor of safety

Estimated Drag Coefficient

• Dynamic similarity not established
• Drag Coefficient of full scale determined by OpenRocket

simulation of full scale

• Estimated Drag Coefficient: 0.41321

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Final Payload Design Overview

Payload Overview

• Target Detection System (TDS)
• Flight Computer
• Sensors
• Camera
• Battery
• Key Dimensions
• Height: 12 inches
• Diameter: 4 inches
• Mass: 176 g

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Electronics Integration

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• Flight Computer serves as

information hub

• SenseHAT connects via

GPIO pins

• Camera connects via USB
• Battery connects via micro

USB

• Raspberry Pi distributes

power from battery connected electronics

TDS Program Logic

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• Autonomous initiation of

TDS

• Analyze images based on

expected RGB, size, and shape of targets

• Interface with SenseHAT

for acceleration data

• Label and store all

identified targets

Payload Electronics

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Flight Computer Software Sensors Camera Battery Raspberry Pi 3B OpenCV on Python 3 Raspberry Pi SenseHAT Mobius Action Camera Zilu Battery Pack

Payload Housing

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• G12 Fiberglass Coupler
• Includes shroud routes
• Includes screw holes
• G12 Fiberglass Bulk Plates
• Eye bolt holes
• Threaded rod holes

Triangular Sled

• 1/4-20 Threaded Steel Rods and Nuts
• 3D Printed ABS Sled Links
• Laser Cut 1/8" Acrylic Sleds
• Each sled is removable
• Facilitate attaching electronics

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Triangular Sled Subassembly

• Includes two diagonal links and sled
• Sled is epoxied to the two diagonal links
• Access holes for connecting cables
• Screw holes for attaching flight computer
• Camera Sled has screw holes for camera

carrier

• Battery Sled has slots for zip ties

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Camera Carrier

• Custom 3D printed ABS
• Power/USB access holes
• Mobius Camera
• Lens removed from casing
• Held at 38.5 degree angle
• Camera press fit into place
• Assembly screwed into triangular

sled

• Camera lens is connected once

entire payload is loaded

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Launch Vehicle Interfaces

• Payload coupler slides into lower airframe
• Rigidly attached with button bolts and PEM broaching nuts
• Connect camera lens to ribbon cable once payload is fixed
• Middle airframe slides over payload coupler
• Rigidly attached with button bolts and PEM broaching nuts
• Shock chord is tied to eye bolt of upper bulk plate

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Status of Requirements Verification

General Update

• Some cannot be verified until the full scale test launch and

full build of rocket

• On Track to completion: Full Completion by mid-February

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Section​ Progress​ To Be Completed​ General​ 13/14​ Educational Outreach​ Launch Vehicle​ 17/21​ Apogee, Preparation Time, Standby Time, Full Scale Test Launch​ Recovery​ 7/11​ Ground Ejection Charges, GPS, Electronics Shielding​ Payload​ 3/5​ Target Detection Accuracy and Testing​ Safety​ 3/5​ Full Scale Test Launch​

Launch Vehicle Requirements

Subsystem Requirement Verification Method Verification Status 2.8 The launch vehicle will be limited to a single stage. This requirement will be met when PLAID is designed with one rocket motor, limited to one stage. Verification will be provided by the final motor selection in CDR. Met; PLAID will be powered by a one single stage rocket motor. 2.17 The launch vehicle will accelerate to a minimum velocity of 52 fps at rail exit. This requirement will be met when the rail exit velocity of PLAID off of a 12ft 1515 rail is above 52 fps. Verification

• f this requirement will be provided by

inspection of OpenRocket models. The planned exit rail velocity will be 74.4 ft/s. Met

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Thank You

Questions?

Special thanks to John Haught, Rod Schafer, and John Brohm!

References

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“Apogee Rockets.” Apogee Rockets, Apogee Rockets, http://www.apogeerockets.com/. Benson, Tom. Velocity During Recovery. NASA, https://www.grc.nasa.gov/WWW/k-12/VirtualAero/BottleRocket/airplane/rktvrecv.html. Cipolla, John. “Fin Flutter and Loads Analysis Software.” AeroFinSim, AeroRocket and Warp Metrics, www.aerorocket.com/finsim.html. “Elastic Constant Converter.” Calculator for Exploring Relations Among the Elastic Constants, EFunda Inc., www.efunda.com/formulae/solid_mechanics/mat_mechanics/calc_elastic_constants.cfm. “G10 Fiberglass Epoxy Laminate Sheet.” Material Property Data, MatWeb, www.matweb.com/search/DataSheet.aspx?MatGUID=8337b2d050d44da1b8a9a5e61b0d5f85 Hennin, Bart. “Apogee Components Peak of Flight Newsletter.” 19 October 2010. Howard, Zachary. “Apogee Components Peak of Flight Newsletter.” 19 July 2011. “How To Size Ejection Charge.” HARA, 18 May 2014, hararocketry.org/hara/resources/how-to-size-ejection-charge/. Hunter, John D. “Matplotlib: A 2D Graphics Environment.” Computing in Science & Engineering, vol. 9, no. 3, 2007, pp. 90–95., doi:10.1109/mcse.2007.55. More About Hard Fiber, Fiberglass, Garolite, and Carbon Fiber. engineering.tamu.edu/media/4247821/ds-garolite-properties.pdf. “NEMA Grade G-10 Glass Epoxy Laminate.” The Gund Company, The Gund Company, thegundcompany.com/wp-content/uploads/2016/11/NEMA-G10-EPGC-201-from-The-Gund-Co.pdf. Newton, Mark, et al. “Rocketry Basics.” NAR Member Guidebook, Jan. 2021, pp. 4–27. Niskanen, Sampo "OpenRocket technical documentation", 10 May 2013. “ Pro54 1750K650-16A.” Pro54, Cesaroni Technology, Inc., www.pro38.com/products/pro54/motor/MotorData.php?prodid=1750K650-16A. “ Pro54 2377K711-18A.” Pro54, Cesaroni Technology, Inc., www.pro38.com/products/pro54/motor/MotorData.php?prodid=2377K711-18A. “Scheme-It.” SchemeIt | Free Online Schematic Drawing Tool | DigiKey Electronics, www.digikey.com/schemeit/project/. “Shape Effects on Drag.” NASA, Glenn Research Center, 5 May 2015, www.grc.nasa.gov/WWW/k-12/airplane/shaped.html. Stein, Stephen D. “Benefits of the Star Grain Configuration for a Sounding Rocket”, Tola, Ceyhun, and Melik Nikbay. “Investigation of the Effect of Thickness, Taper Ratio and Aspect Ratio on Fin Flutter Velocity of a Model Rocket Using Response Surface Method.” Research Gate, 7th International Conference on Recent Advances in Space Technologies, June 2015. Van Milligan, Tim. “Apogee Components Peak of Flight Newsletter.” 18 December 2012. Van Milligan, Tim. “Apogee Components Peak of Flight Newsletter.” 2 May 2017. “Wing Geometry Definitions.” NASA, Glenn Research Center, 5 May 2015, www.grc.nasa.gov/www/k-12/airplane/geom.html.