critical design review - umbra · 2019. 10. 25. · critical design review january 26, 2018...

Critical Design ReviewJanuary 26, 2018

California State Polytechnic University, Pomona

3801 W. Temple Ave,

Pomona, CA 91768

7.0 Subscale Vehicle Overview

6.0 Test Plans and Procedures

5.0 Mission Performance Predictions

4.0 Recovery Subsystem

Agenda

1.0 Introduction

2.0 Final Launch Vehicle Overview

3.0 Launch Vehicle Performance

8.0 Payload Overview

9.0 Launch Vehicle Interfaces

10.0 Project Plan

01/26/2018 California State Polytechnic University, Pomona | CDR 2017-2018 1

o Competition Week Attendees

o Major Changes from PDR

Agenda

1.0 Introduction


Competition Week Attendees2017-2018 Cal Poly Pomona NASA

Student Launch Initiative

Educator Administrators

Advisor

Donald Edberg, PhD

Mentor

Todd Coburn, PhD

L2 TRA Mentor

Rick Maschek

Lead Engineer

Casey

Aerodynamics

Aerodynamics Lead

Daniel R.

Ryan

Andrew

Verenice

Mauricio

Vanessa

Daniel A.

Structures

Structures Lead

Edgar

Kevin

Priya

Cory

Isaac

Jehosafat

Leara

Payload

Payload Lead

Richard

Juan

Ricardo

Praneeth

Courtney

Deputy, Systems Engineer

Megan

Safety Officer

Natalie


Changes Made Since PDR

Criteria Changes Made

Vehicle SizeOverall length increased from 7 ft-9

in to 8 ft-5 in

Vehicle MassOverall mass decreased from 46 lb

to 43.7 lb

Nose Cone

Material changed from PLA and

fiberglass reinforcement to PLA

only.

Fin

Material changed from PLA and

fiberglass reinforcement to PLA

only.


Recovery GPS

Redundancy added for GPS;

Trackimo GPS has been added in

addition to the Eggfinder

Drogue Parachute Size changed to 4 ft2

Main ParachuteDeployment altitude changed from

500 ft to 600 ft.

Motor Selection

Motor has changed from a

Cesaroni L1115 to an Aerotech

L1420R

• Vehicle Criteria Changes


Changes Made Since PDR


GPS Module

Adafruit module replaced by the Eggfinder

system; Adafruit transceivers replaced by

XBee modules.

Payload Observation Avionics

Live video feed and camera eliminated: The

ground station will now consist of a laptop

with the Eggfinder RX and the ground XBee

both connected independent from one

another via USB.

• Payload Criteria Changes






Agenda

1.0 Introduction





10.0 Project Plan


o Final Launch Vehicle: Dimensions

o Final Launch Vehicle: Full Configuration

o Mass Statement and Mass Margin

o Key Design Features: Hollowed Bulkhead

o Key Design Features: Plug

o Key Design Features: Recovery Avionics Bay

o Key Design Features: Fin Integration

o Final Motor Choice and Justification

Agenda



Final Launch Vehicle: Dimensions

● 3 Independent sections known as Modules

○ Module 1 : Nose cone, Payload Bay

○ Module 2 : Recovery system

○ Module 3 : Observation Bay and Motor Bay

● Total Length of Launch Vehicle: 101 in. (8 ft-5in)


Final Launch Vehicle: Full Configuration


Mass Statement and Mass Margin

● Total Mass of Launch vehicle

○ At Lift off: W = 43.7 lb

○ At Burnout: W = 38.1 lb

● Mass Margin

○ Desirable Altitude

■ Lift off weight between 43 lb and 52 lb

○ Desired Flight Stability

■ Payload must not exceed 5 lb and implement a 10% ballast


Key Design Features: Hollowed Bulkhead

● Located and epoxied to

the end of the Payload

Bay

● Provides an opening for

DARIC Rover to exit

● Attached to main

parachute shock cord via

Zinc-plated Steel U-bolt


Key Design Features: Hollowed Bulkhead

● Manufactured using ¾’’

Birch Plywood and

sandwiched between two

0.032’’ 7075-T6 Al sheets

● Al sheets provide greater load

capabilities during main

parachute deployment


Key Design Features: Plug

● Fitted to cover hollowed

bulkhead opening

○ Creates pressure seal for

main parachute deployment

○ Protects payload from

deployment charge debris

● Gets pulled off with main

parachute deployment by

attaching routing eye-bolt to

shock cord line

● Manufactured by 3-D printer

using PLA material


Key Design Features: Recovery Avionics Bay

• Made of Blue Tube 2.0 coupler• 12 in. length• OD:5.976in• ID: 5.835in• Enclosed by two ¾’’ Birch plywood

bulkheads• Two ½’’ holes will be created through

the collar to fit exterior controlled switches


Key Design Features: Recovery Avionics Bay

● Avionics plate

made of thin

plywood will hold

altimeters

● Two threaded rods

will hold avionics

plate in place

during flight


Key Design Feature: Fin Integration

• Consists of 3 fins, 4 centering rings, and 6 bolts

• Body Tube shrouds and protects Fin Integration System

• Allows for fast and easy replacement of fins

• Broken fins do not ground the launch vehicle


Key Design Feature: Fin Integration

• Centering rings at the end are fixed with bolts, middle centering rings are friction fit

• Bolts ensure a secure connection

• Fins can be replaced in under 5 minutes

• Less time repairing = More time flying


Final Motor Selection and Justification

Aerotech L1420 Performance Parameters:

Average Thrust: 319.23 lbfMaximum Thrust: 407.80 lbfTotal Impulse : 1034.80 lbf-sBurn Time: 3.2 secondsISP: 183 seconds

Aerotech L1420 Thrust Curve



Aerotech L1420 enabled:• Cost Savings:

• From $458 -> $208• Savings Factor: Aerotech

Casing available on site

• Satisfies Apogee Requirement (5331-5507 ft.)

• Satisfies Rail Exit Velocity Requirement (60.5 ft/s)

Aerotech L1420 Thrust Curve



• Apogee Simulations:

• OpenRocket: (5331-5507 ft.) from 0 to 20 mph winds

• MATLAB: 5745 ft.

• Difference (%): 2.38%

• Allows 0-10% ballast to further refine the altitude






Agenda

1.0 Introduction





10.0 Project Plan


o Rocket Flight Stability in Stability Margin Diagram

o Thrust-to-Weight Ratio and Rail Exit Velocity

Agenda



Center of Gravity

Center of Gravity

(OpenRocket)

62.695 in.

Center of Gravity

(Hand Calculations)

63.520 in.

Percent Difference 1.31%


Center of Pressure

Center of Pressure

(OpenRocket)

78.014 in.

Center of Pressure

(Hand Calculation)

77.320 in.

Percent Difference .89%


Stability Margin

Stability Margin

(OpenRocket)

2.62 Caliber

Stability Margin

(Hand Calculation)

2.24 Caliber

Percent Difference 14.5 %


Launch Vehicle Performance

● Thrust-to-Weight ratio

○ T / W = 7.3

● Rail Exit Velocity based on MGLOW = 43.7 lb

○ Using the 8 ft. 1515 rail: V = 60.7 ft/s

○ Using the 12 ft. 1515 rail: V = 75.1 ft/s






Agenda

1.0 Introduction





10.0 Project Plan


o Parachute Overview

o Parachute Sizes

o Recovery Harness

o Recovery Avionics: Altimeters

o Recovery Avionics: Ejection Charge

o Recovery Avionics: GPS

Agenda



Parachute Overview

Main Drogue

• Toroidal design• Manufactured by Fruity Chutes• Packing Volume: 199.9 ft3

• Weight: 3 lbs.• 400 lb. paraline

• Cruciform design• Manufactured in-house• 10 inches of tube allocated for stowage• Weight: 1 lb.• 400 lb. paraline


Parachute Sizes

Main Drogue

• Diameter: 10 ft.

• Spill Hole Diameter: 1.77 ft.

• Aeff = ~80 ft2

• Cd of 2.2

• Gores: 34 in. x 10 in

• Aeff = 4 ft2

• Cd of 0.6


Recovery Harness

• ¼ in. Kevlar shock cord rated at 2200 lbs

• Measuring 30 ft each for both parachutes

• Attached using ⅜ in. steel quick links for main and ¼ in. steel quick links for the drogue


Recovery Avionics: Altimeters

● Two (2) PerfectFlite Stratologger CF altimeters will be

used for Drogue and Main parachute deployment

● Redundancy established using two separate altimeters

● Each will run on 9V batteries


Altimeter Specifications

StratologgerCF● Main chute deployment range from 100 to 9,999 feet in 1 foot demarcations

● Drogue Chute Deployment at Apogee

● Stores 16 eighteen minute flights

● 5 Amp output current

● Altitude, Temperature, Power Supply voltage data collection


Parachute Deployment Figures

Stratologger 1 Stratologger 2

Drogue Deployment At Apogee (5,280 ft) 2 seconds after Apogee

Main Deployment 600 ft 500 ft

● Each altimeter will be programmed with different main chute

deployment values

● In the case of main altimeter failure, the redundant altimeter

will deploy the drogue/main chute(s)


Recovery Avionics: Ejection Charge

• There are a total of 4 charges located on rocket• 2 for the Drogue Parachute• 2 for the Main Parachute

• 4F Black Powder will be used• Charge sized calculated taking into account changes

in bay size• Calculations will be verified using ground tests.

Charges will be optimized to ensure proper ejection• Ignition method : E match


Recovery Avionics: GPS

● Two GPS systems (Eggfinder and Trackimo) will be utilized

● Varying frequencies allow for additional redundancies in rocket

recovery

● Immediate uplink of data to ground command module with

integrated hardware


GPS Specifications

Eggfinder● 9 Volt power supply

● 8.2 ft accuracy

● 900 Mhz transmitting

● Range of 8000 ft

Trackimo● Rechargeable LiPo Battery

● 50 ft accuracy

● 850/900/1800/1900 MHz transmitting

● Unlimited Range with cell service

permitting


GPS Data Pathways

Eggfinder Trackimo

● Two separate location data pathways ensure higher success rate in recovery

as a failure of one system will not affect the alternative






Agenda

1.0 Introduction





10.0 Project Plan


o Descent Rates

o Kinetic Energy at Key Phases

o Drift Predictions from Launch Pad

Agenda



Descent Rates

• Descent Rate From Apogee to Main Deployment (when drogue is deployed) = 120 ft/s

• Descent Rate from Main Deployment to Touch Down = 14 ft/s

• Total time spent in air = 81.9 seconds


Kinetic Energy at Key Phases

• Max Kinetic Energy and Kinetic Energy at touchdown identified• Requirement 3.3 satisfied

Phase

KE of Nose Cone +

Payload Fairing

(0.247 slugs)

(ft-lbs)

KE of Main/Drogue

Bay + Recovery Bay

(0.291 slugs)

(ft-lbs)

KE of Observation

Bay + Motor Bay

(0.508 slugs+0.314

slugs for prop mass)

(ft-lbs)

Total Kinetic Energy

(ft-lbs)

Rail Exit (60.7 ft/s) 455.2 536.5 1515 2506.7

Apogee (0 ft/s) 0 0 0 0

Drogue Deployment

(120 ft/s)1779 2097 3661 7370

Main Deployment &

Touchdown (14 ft/s)24.2 28.5 49.8 102.5


Drift Calculations

• To address concerns and meet the drift radius requirement, the main will now deploy at 600 ft (with backup charge at 500 ft).

• New descent rates = 120 ft/s with drogue deployed & 14 ft/s with main deployed

• Drift distance can be minimized further because main deployment velocity is conservative

Wind Velocity (mph) Drift Distance (ft)

0 0

5 624

10 1248

15 1873

20 2497






Agenda

1.0 Introduction





10.0 Project Plan


o Test Plan Matrix

o Safety Plan

Agenda



Test Plan Matrix


Test Plan Matrix


Camera must be capable to

record for a minimum of 1

hour.

Controlled:

-Raspberry Pi Zero

computer and camera

Measured:

-Battery compability

Completed:

1/15/18

Parachute

Drop Test

Verify Req. 3.1 and 3.3 to ensure that the

provided kinetic energy during drogue-stage

descent is reasonable.

Verify Req. 3.3 to ensure the kinetic energy does

not exceed 75 ft-lb by determining the

parachutes' velocity.

Predicted parameters are

verified. The drogue and main

parachutes completely inflate.

Controlled:

-5 lb. weight

-Parachute size

-Drop distance height

Measured:

-Descent time

-Parachute inflation

Scheduled:

1/28/18

Observation

System Test

Raspberry Pi Zero with camera will provide

flight profile verification.

Test Plan Matrix


Safety Plan


Safety PlanSafety Plan






Agenda

1.0 Introduction





10.0 Project Plan


o Subscale Vehicle Overview

o Subscale Launch Vehicle Scaling

o Subscale Flight Results

o Predicted vs True

o Subscale Lessons Learned

Agenda



Recovery

BayMain Parachute

Drogue

Parachute

Observation

Bay

Subscale Vehicle Overview


Launch Vehicle

CharacteristicsSub-Scale

Body Tube Diameter (in.) 3.0

Overall Length (in.) 58

Overall Mass (lbs.) 7.84

Static Margin (Caliber) 2.59

Motor Bay with

Removable Fin Integration

Subscale: Scaling and Layout

Geometric Scaling Factor - 1:2 Scale (B.T. Diameter)

Launch Vehicle

CharacteristicsFull-Scale Sub-Scale

Scaling Factor (Sub-

scale/Full-Scale)

Body Tube Diameter

(in.)

6.0 3.0 0.500

Overall Length (in.)101 58 0.574



Goals for the Subscale

• Test all flight electronics to be used in full-scale

• Test scaled down recovery system layout

• Test launch vehicle geometry and stability to prove full-scale integrity



Electronic

Component

Full-Scale

Usage

Sub-Scale

Usage

Raspberry Pi w/

Camera moduleYes Yes

EGGFINDER GPS Yes Yes

Trackimo GPS Yes No

Stratologger CF

AltimeterYes (2) Yes (2)

Flight Electronics



Recovery System

F.S.

S.S.

Main Altimeter

Drogue



Characteristic Full-Scale Sub-Scale

Stability 2.62 Caliber 2.59 Caliber

FinsNACA 0008 Clipped

Delta (Removable)

NACA 0008 Clipped

Delta (Removable)

Nose Cone Von-Karman Von-Karman

Geometry and Stability


Subscale Flight Results

● Flight data provided by two altimeters

● Apogee = 4313 feet

● Launch Conditions: cloudy skies, 59 degrees Fahrenheit, average wind speed of 16 mph


Predicted and Actual Flight Data

● Initial drag coefficient for subscale was 0.49

● Obtained from OpenRocket simulations using launch day conditions

● Altitude predicted with MATLAB


Predicted and Actual Fight Data

● Drag coefficient of 0.64 obtained from flight data using MATLAB

● Altitude predicted with MATLAB


Calculated Drag Coefficients

Subscale Model Full Scale Model

OpenRocket 0.49 0.45

MATLAB 0.64 0.59

Error 30.6% 30.6%


Subscale Model: Lessons Learned

● MATLAB program assumes vertical flight and does not

simulate launch day conditions

● OpenRocket and MATLAB program can predict rocket

altitude accurately

● Flight test data needed to determine drag coefficient

● Ensure that all checklists for full scale model are

followed






Agenda

1.0 Introduction





10.0 Project Plan


o Final Payload Design Overview

o Payload Dimensions

o Key Design Features

o Payload Electronics Overview

o Payload Integration

Agenda



DARIC - Assembly


DARIC - Payload Dimensions

Note: dimensions are in inches


DARIC - Key Design Features

• Compact design

• Easy Assembly

• Lightweight

• Simple Manufacturing Method -3D printed PLA

• Solar deployment system can be easily integrated to the top of the rover.


Key Design Features: SPOC System

• Pendulum system allows for orientation correction upon landing

• Pin restricts movement during flight• Carriage system securely holds

rover during descent


Key Design Features: SPD System

• Rotary servo holds down foldable solar panels

• Uses torsion springs to open up the solar panels

• Easily mounts on top of the rover allowing for easy access


Payload Electronics Overview

On the rover:

• Electrical• Raspberry Pi Zero• Sixfab shield• Xbee Transceiver (900 MHz; 250 mW)• Eggfinder GPS module

• Motorized• 2 Micro servos• 1 main motor


Payload Electronics Overview

A depiction of the schematic design


Payload Integration

• Raspberry Pi, Sixfab Shield, and Xbee transceiver unit will be used to make coding easier

• The coding system will be autonomous and run on a series of infinite loops

• Coding will be broken up into two sections• Code for electronic components• Code for motorized components

• When both sections have been tested enough, they will be merged together into a master program


Payload Integration

Data transmission

• GPS data• Sent directly to ground

dongle. • Data log

• Transceiver data • Xbees linked in a mesh

network• Ground station will be

mesh coordinator






Agenda

1.0 Introduction





10.0 Project Plan


Internal Interfaces Within Launch Vehicle

• 12 bolts hold SPOC

system to Launch

Vehicle

• Rotation Lock Pin is

tethered to the Main

Parachute via a steel

cable






Agenda

1.0 Introduction





10.0 Project Plan


o Status of Requirements Verification

o Timeline

Agenda

10.0 Project Plan


Verification Methods

Nomenclature -


Launch Vehicle Compliance Matrix


Recovery System Compliance Matrix


Payload Compliance Matrix


Safety Compliance Matrix


General Compliance Matrix


Derived Requirements Matrix


Gantt Chart


Important Milestones


Thank you, 2017-2018 CPP NSL Team

Questions or Comments?

critical design review - umbra · 2019. 10. 25. · critical design review january 26, 2018...

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