the notre dame rocketry teamdaniellavelle.com/cdr_pres.pdfflight # conditions raven apogee...

THE NOTRE DAMEROCKETRY TEAM

Critical Design ReviewJanuary 28, 2020

11 AM CST

General Vehicle Recovery System Payload Experiments Safety Conclusions

NDRT Competition Vehicle & Team

2


Contents

1. General2. Vehicle3. Recovery System4. Payload Experiments5. Safety6. Conclusions

3


General Requirements Verification

4

Req. ID

Description Verification Plan Status

1.3Foreign National (FN) members must be identified by PDR.

Leads ensure FN proper registration and inform FN

members of the launch week restrictions.Completed

1.4The team must identify all team members attending launch week.

Members, mentors, and educators express interest in attending launch week prior to CDR submission. Completed

1.5The team will engage at least 200 participants in educational, hands-on STEM activities.

An STEM Engagement lead communicates outreach activities and submits summary reports. Completed

1.6The team will establish a social media presence. A Social Media lead maintains the team’s online presence

and interaction with the public. Completed

1.8All deliverables must be in PDF format. Documentation is prepared using Overleaf and is compiled

into PDF format. Completed

1.9The team must provide a table of contents in every report.

Documentation prepared using Overleaf contains an automatically generated table of contents. Completed

1.10The team must include page numbers at the bottom of every report page.

Documentation prepared using Overleaf is formatted to include the page numbers. Completed

1.12The team must use the launch pads provided by NASA SL launch services provider.

The launch vehicle is designed to launch with the required launch pads and rails. Completed


Contents


5


Launch Vehicle Overview

6

Req. ID Description Verified

2.5“The launch vehicle will have a maximum of four (4) independent sections.…”

✓

Sections 4

Separation Points 3

Vehicle Length 134 in.

Vehicle Loaded Mass 839 oz

Vehicle Rail Used 12 ft. 1515

General Vehicle Recovery System Payload Experiments Safety Conclusions 7

Section Label Component Length [in] OD [in]

I ANose Cone 24

8Telemetry 5.5

IIB Payload Bay 23

C Transition Section 5 Variable

III D

Recovery Tube 36

6.112

Main Parachute* 21

CRAM* 6

Drogue Parachute* 6

IV

FFin Can 44

ABS* 12

G Motor Mount* 24 3

E Fins* 6.5 (height) N/A


Mass & Material Statement

8

Total Loaded Mass 839 oz

Component Mass [oz] Materials

Nose Cone 70.0 ASA Plastic

Payload Bay 57.4 Fiberglass

Transition Section (Includes Camera Shroud, Bulkhead,

Centering Rings & Coupler)

39.8 Various

Recovery Tube 52.4 Carbon Fiber

Fin Can(Includes Epoxy & Centering Rings for

Motor Mount)

125.7 Carbon Fiber

AIRFRAME TOTAL 357.3


Static Stability

9

Loaded Stability [cal] Rail Exit Stability [cal] Unloaded Stability [cal]

2.63 2.70 3.94

Center of Gravity Location 75.8 in.

Center of Pressure Location 96.4 in.

Mass Margin 20 oz


2.14.“ minimum static stability margin of 2.0 at the point of rail exit...” ✓


Nose Cone

10

• Ogive geometry• 3D printed using ASA plastic

– 3-part assembly• Integrated telemetry module• 24 in. length• 4 in. shoulder


Transition Section

11

• Transition Section– Student Fabricated: ASA Plastic– 8 in. to 6 in. diameter transition– Avoid flow separation

• On Board Camera– Spytec Mini HD


Motor Selection

12

Cesaroni L1395 Spec Value

Total Impulse 1101.46 lb-s

Burn Time 3.51 s

Average Thrust 314.03 lb

Maximum Thrust 400.48 lb

Maximum Acceleration 214 ft/s2

Rail Exit Velocity 64.3 ft/s

Thrust-to-Weight Ratio 32.95 : 1

Motor Selection: Cesaroni L1395 Blue Streak


2.8.“The launch vehicle will be capable of being launched by a standard 12-volt direct current firing system...”

✓

2.10.“The launch vehicle will use a commercially available solid motor propulsion system…” ✓

2.12.“The total impulse provided by a… University launch vehicle will not exceed… (L-class)...” ✓

2.16.“The launch vehicle will accelerate to a minimum velocity of 52 fps at rail exit.” ✓


Performance Predictions

13

ScenarioApogee [ft]

OpenRocketApogee [ft]

Matlab

5o Rail Cant, 0 mph Winds 4939 4947





• Target Apogee of 4,444 ft achievable

• ABS system used in to reduce apogee at most by 500 ft

Simulated Flight for Varying Wind Speeds


Fins

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• Material: Fiberglass

• Shape: Trapezoid

• Integration:

– Four 0.125 inch slots cut into fin can

– Fins attached to launch vehicle at motor mount and body through slots

• Fin Flutter:

Measurement Value

Height 6.5 in.

Root Chord 6 in.

Tip Chord 3 in.

Sweep Angle 13°

Thickness 0.125 in.

Max VelocitySlower than Vf

589 ft/s ✓


Scale Model Flight Test Data

• December 7th Subscale Launch in Three Oaks, MI

15

Flight # Conditions Raven Apogee Stratologger Apogee

Flight 1 No Tabs 1367 ft AGL 1365 ft AGL

Flight 2 Full Tabs 1011 ft AGL 1009 ft AGL

Flight 3 Half Tabs & Camera 1127 ft AGL 1126 ft AGL


2.17.

“All teams will successfully launch and recover a subscale model of their rocket prior to CDR...”

✓


Scale Model Flight Test Data, cont.

Fourth Order Runge-Kutta simulation

16

Altitude Simulation Vs. Actual Flight 𝝈 = 0.914 Velocity Simulation Vs. Actual Flight 𝝈 = 0.645


Test Plans & Procedures

17

Req. ID

Description Pass/Fail Criteria Date Planned

2.4

Solids Testing - Vehicle must be able to be recovered without damage and relaunched in the same day

Success - Strength properties of various bulkhead materials

are verified AND suitable material choices are confirmed

Fail - Strength properties of various bulkhead materials are

not verified

Scheduled:

January 24-

31

2.18

Full Scale Flight Test Demonstration - All teams will complete a demonstration flight as outlined in Req. 2.18.1-2.18.2.4

Success - Launch confirms that hardware is functioning

properly AND flight is stable AND no damage is sustained

AND payload system accomplishes simulated mission

Fail - Hardware does not function properly OR flight is

unstable OR damage is sustained OR payload is unable to

accomplish simulated mission

Scheduled:

February 8,

15, or 29


Contents


18


Design Overview

• Dual Deployment Recovery System– Drogue and Main parachutes in separate bays– Drogue deployed at vehicle apogee– Main deployed at 600 ft AGL– Nose Cone Separation at 400 ft AGL

19

Recovery Tube

Main CRAM Drogue


Parachute Selection

• FruityChutes 24 in. Elliptical for Drogue– 24 inch Nomex blanket protection

• FruityChutes 120 in. Iris Ultra Compact for Main– Nomex deployment bag – 24 in Pilot Chute to facilitate deployment

20

Drogue Parachute

Specification Value

Diameter 2 ft

CD 1.5

Shape Elliptical

Weight 2.2 oz

Main Parachute

Specification Value

Diameter 10 ft

CD 2.2

Shape Toroidal

Weight 22 oz


Performance

• Terminal Velocities and descent times calculated using three methods

• Drift predictions made using two methods

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Simulation Method Terminal Velocity [ft/s] Terminal Kinetic Energy [ft-lbs] Calculated Descent Time

OpenRocket 15.6 61.6 85.7

FruityChutes Calculator 15.2 58.7 86.9

MATLAB Simulation 15.0 57.1 88.3


3.3“Each independent section of the launch vehicle will have a maximum kinetic energy of 75 ft-lbf at landing.”

✓

3.11“Descent time will be limited to 90 seconds (apogee to touch down)” ✓


Predicted Drift

22

Wind Speed [mph]

Predicted Drift [ft](OpenRocket)

Predicted Drift [ft](MATLAB Simulation)

5 546 504

10 1130 1049

15 1717 1611

20 2226 2184


3.10.“The recovery area will be limited to a 2,500 ft radius from the launch pads.” ✓


Hardware

• OneBadHawk 1 inch Tubular Nylon shock cord, two 35 ft lengths

– 4000 lb breaking strength

• 3/8 in. Stainless steel quick links

– 2700 lb static load, 6000 lb shock load

• 3/8 in. Galvanized steel eye bolts– 1400 lb static load, 3100 lb shock load

23


Electronics

• 3 independently powered altimeters– 2 Raven3– 1 Stratologger SL100– Each controls 1 drogue and 1

main ejection charge• 3.7v 170mah Lithium-Polymer

batteries– One for each altimeter

• Activation Switches– Magnetic Switch– Rotary Switch

24


3.4“The recovery system will contain redundant, commercially available altimeters.” ✓

3.5“Each altimeter will have a dedicated power supply, and all recovery electronics will be powered by commercially available batteries.”

✓

3.6“Each altimeter will be armed by a dedicated arming switch that is accessible from the exterior …”

✓

3.7“Each arming switch will be capable of being locked in the ON position for launch (i.e. cannot be disarmed due to flight forces).”

✓

3.8“The recovery system electrical circuits will be completely independent of any payload electrical circuits.”

✓


Electronic Diagrams

25

Raven3 Wiring Diagram Stratologger Wiring Diagram


Compact Removable Avionics Module

26


Loads & Safety Factors

• Assumption of instantaneous parachute opening

• Simple Euler’s method used to solve equation of motion

• Assumed equal acceleration across entire vehicle, due to tethering

27

Component Factor of Safety

Quicklinks 3.4

Shock Cord 2.3

Eyebolts 4.1

ABS Bulkhead 11.9

CRAM Top Bulkhead 5.9

CRAM Bottom Bulkhead 4.0

CRAM Body 6.2

CRAM Adapter 20.6

Payload Bulkhead 3.7



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Req. ID


3.4

Altimeter Testing - “The

recovery system must contain

redundant, commercially

available altimeters…”

Success - Altimeters successfully light the e-match

substitute at the appropriate altitude during simulated

flight.

Fail - E-match substitute does not light, or lights at the

wrong time during simulated flight.

Scheduled:

January 27-

February 2

3.2

Black Powder Separation Testing - Each team must perform a successful ground ejection test for both the drogue and main parachutes.

Success - All vehicle sections successfully separate and all

parachutes fully exit the body tubes.

Fail - At least one section fails to separate, or a parachute

fails to exit the vehicle body tube

Scheduled:

February 2-8


Contents

1. General2. Vehicle3. Recovery System4. Payload Experiments

– Lunar Sample Retrieval System (LSRS)– Air Braking System (ABS)

5. Safety6. Conclusions

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System Breakdown

30

LSRS

Deployment

Rover

UAV

Sample Retrieval

Retention OrientationTarget

Detection


Design Overview

• UAV– Uses computer vision to

locate and send coordinates of closest CFEA

31

• Rover– Traverses terrain to UAV

coordinates and retrieves lunar sample

Rover

RoverUAV

UAV


Vehicle Integration

• Sled and Rail – Rails are fixed to the Aft-

Bulkhead– Sled is secured to the Rails

using nuts and bolts– Easy access and facilitates

assembly

32


ROD System: Overview

• Nose Cone Ejection– 4 Solenoid Pins

• Bearing on Aft bulkhead orients LSRS

• UAV sled for UAV deployment

• Rover tows UAV– Quick link detachment

after deployment

33


ROD System: Retention

• 4 Adafruit Medium Push-Pull Solenoids– Inserted into UAV Sled and Rover Body– Stainless Steel pins– Provide mechanical fail-safe

• 2 Stationary Rods Secure UAV

34


4.3.7

“Any part of the payload or vehicle that is designed to be deployed, whether on the ground or in the air, must be fully retained until it is deployed as designed.”

✓


ROD System: Nose Cone Ejection

• Facilitate deployment of LSRS• PerfectFlite Stratologger SL100• 1/8 in. Kevlar Tether Chord

35


ROD System: Orientation

• Steel Bearing press-fit into 1/8 in. G10 bulkhead• Motorless orientation

– Center of Gravity off-center• Locked in flight by fore-bulkhead

36


ROD System: FEA

37

ComponentFactor of

Safety

Sliding Platform

4.75

Stationary Platform

4.24

Orientation Bearing

14.67

Aft Bulkhead 5.20

Solenoid Pins 3.32

Aft Bulkhead

Stationary Platform

Sliding Platform


ROD System: Electronics

• Adafruit Itsy Bitsy 3 V Controller

– Rover radio receives release command

– Receives commands through wire headers from rover

– Trigger retracts 4 solenoids

– Rover pulls apart connection as it drives out

38


UAV: Mechanical

• Carbon Fiber Platforms• Aluminum 6061 Spacers and Struts• Total Weight: 17 oz• 6.10 in. x 6.10 in. x 2.50 in.

39


4.4.4

“Any UAV weighing more than .55 lbs. will be registered with the FAA and the registration number marked on the vehicle.”

✓


Motors, Propellers, Battery

• Motors– EMAX RS1306B V2 4000 Kv

• Propellers– HQ 3020 Bi-Blade 3 in. x 2 in.

• Battery– Lumenier 3S2P 5000 mAh Li-Ion

40


UAV: Electronics

41


UAV: Electronics

• 5.8 GHz video transmission– 200 mW

• 915 MHz control transmission– 100 mW

42


2.22.9

“Transmissions from onboard transmitters will not exceed 250 mW of power (per transmitter).”

✓


Target Detection

• Utilize OpenCV python library for software functions

• Identify CFEA using geometric features, color contrasting, boundary conditions

43


Target Detection: Search Algorithm

• Monte Carlo simulation built to test 3 paths– Analyzed for accuracy & time

• Time for all was prohibitive– Instead, informed search implemented– Uses linear sweep on smaller regions

44


Target Detection: Ground Station

• Raspberry Pi with transceivers for UAV & Rover

– Separate Rx for UAV video• Runs target detection, autonomous control• Manual control by independent controllers for

both UAV & Rover

45


Rover Mechanical: Overview

• Eccentric Crank Rover• System Parameters

– 6.25 in. x 11.20 in. x 3.91 in.– 38 oz

46


Rover Mechanical: Rover Body

• 3D printed ASA • Journal bearings • Cutout for Sample Retrieval

47


Rover Mechanical: Links

• 3D printed ASA • Journal Bearings • Recess for battery placement

– Secured with zip ties

48


Rover Mechanical: Crank Wheel

49

Component Material

Hub Aluminum

Cover HDPE

Axle Aluminum


Rover Mechanical: FEA

50

Component Factor of Safety

Link 4.16

Body 3.84

Crank Wheel

2.61

Body

CrankWheel

Link


Sample Retrieval: Overview

• Screw of Archimedes

• 3D printed PLA • Sample deposited in enclosed

box– Volume: 10.26 cm3

51


4.3.3“The recovered ice sample will be a minimum of 10 milliliters (mL).” ✓


Sample Retrieval: Integration

52

• Deployment– Mounted onto the front end of rover– Rack and pinion

• Connected to high torque motor

• Usage

– Adafruit continuous motor


Rover Electronics: Major Components

• MCU: PIC32• Radio: RFM95W-915S2

– 915 MHz LoRa radio – 100 mW output power

• GPS: MTK3339• IMU: BNO055

– Tilt compensated compass heading

53


2.22.9

Transmissions from onboard transmitters will not exceed 250 mW of power (per transmitter).

✓


Rover Electronics: Motor Control

• Two Actobotics 98 RPM Econ Gear Motors

• Sabertooth 2x5 Motor Controller– 2 channels, 5 A per channel– Serial communication and PWM

control modes

54

Actobotics Econ Gear Motor

Specification Value

Torque 524 oz-in.

Speed 98 RPM

Voltage 12 V

Stall Current 3.8 A


Rover Electronics: PCB

55

• Two 11.4 V, 1800 mAh LiPo batteries• 5 V buck converter• 3.3 V linear regulator • 3.3 to 5 V logic shifter for PWM• Custom circuit board


Rover: Software

• Hosted on PIC32• Programs to progress

the rover through mission stages

• Flowchart guides structured software development

56


LSRS: Test Plans & Procedures

57

Description Date Planned

Deployment: Payload Orientation Testing Scheduled: Jan. 27-31

Deployment: Solenoid Actuation Testing Scheduled: Jan. 27-31

Deployment: Vibration & Motion Restriction Scheduled: Feb. 2-8

Deployment: Ground Test Scheduled: Feb. 2-8

Rover: Drive Train Test Scheduled: Jan. 27-31

UAV & Rover: Manual Control Scheduled: Jan. 27-31

UAV & Rover: Autonomous Control Scheduled: Feb. 2-8

UAV: Video Feed Scheduled: Feb. 2-8

UAV: Target Detection Scheduled: Jan. 27-Feb. 8


Contents

1. General2. Vehicle3. Recovery System4. Payload Experiments

– Lunar Sample Retrieval System (LSRS)– Air Braking System (ABS)

5. Safety6. Conclusions

58


Design Overview

• Objective: Achieve apogee of 4,444 ± 25 ft

• Autonomously controlled drag surfaces

59

Top view


Mechanism

• Servo motor rotation → central hub rotation →linkages push drag tabs radially outward

60

Tab extension vs. servo rotation


Sub-Scale Drag Tabs

• Removable 1:4 scale tabs - no extension- half extension- full extension

• Fabricated from Nylon 6/6

61

Sub-scale Flight Results

No Tabs Half Tabs Full Tabs

1366 ft 1126.5 ft 1010 ft

Tabs decrease apogee: verified ✓


Servo Motor

● Hitec D845WP- Programmable PWM Digital

Amplifier- Internal feedback

potentiometer- Powered by 7.4 V battery

62

Hitec D845WP

Stall Torque 694 oz-in.

Speed 0.17 sec/60°

Weight 8 oz


Electronics Hardware

• Components integrated on single PCB– Raspberry Pi Zero flight controller– BNO055 for orientation data– ADXL345 for acceleration data– MPL3115A2 for altitude data– PowerBoost 500 to convert voltage– LEDs to verify power and data collection

• Powered by 3.7 V battery

63


Control Structure

64

Stage Description

ArmedWhen the external switch for sensors is activated, turn on the armed confirmation LED, the module changes to Armed, starts to read data from sensors and runs the filtering module.

LaunchedWhen either the acceleration is greater than the threshold acceleration for a lift-off or the altitude is greater than the threshold altitude, the module changes from Armed to Launched.

BurnoutWhen the acceleration is smaller than the threshold acceleration for Burnout, the module changes from Launched to Burnout module and the PID control module is run.

ApogeeWhen the altitude is greater than the threshold altitude for the designated height of apogee, the module changes from Burnout to Apogee and the PID control module is stopped.

LandedWhen the altitude is smaller than the designated altitude or the velocity is smaller than the threshold, the module changes from Apogee to Landed.


Code Architecture

65


Kalman Filter

• Used to correct sensor noise throughout flight

• Filter coefficients tested and calibrated using subscale flight data

66

Kalman filter applied to sub-scale flight data


PID Algorithm

• Ideal flight path from OpenRocket simulation

• Outputs servo motor rotation angle

67

Simulated flights demonstrating PID success



68


Mechanism & Motor Ground Testing - Servo motor will rotate to correct angle for a given PWM signal.

Success - When PWM signal is sent, servo motor rotates to

correct angle despite resistance due to friction.

Fail - Servo motor does not rotate to proper angle OR motor

stalls due to resistance from friction.

Scheduled:

Feb. 2-8

Control Structure Ground Testing - Kalman filter successfully eliminates noise in flight data, and system successfully responds to simulated flight.

Success - Flight data passed through Kalman filter does not

include extraneous points AND PID algorithm induces drag tab

extension in response to inputted flight data.

Fail - Kalman filter is unable to eliminate noise OR drag tabs

do not actuate correctly in response to simulated flight.

Scheduled:

Feb. 2-8


Contents


69


Safety

• FMEA Tables up to date– Mitigations in place– Verifications in progress

• Launch checklists developed• Construction procedures developed• Workshop certifications completed for

members participating in construction• Safety manual updates in progress

70


5.1. “Each team will use a launch and safety checklist…”

✓

5.3.2. “Implement procedures developed by the team for construction…”

✓

5.3.3. “Manage and maintain current revisions of the team’s hazard analyses…”

✓


Contents


71


NDRT 2020 Competition Vehicle

72

The Notre Dame Rocketry Team has successfully designed a high-powered vehicle to reach an apogee of 4,444 ft. The team will continue to build and testthe vehicle to ensure a safe and successful launch,

recovery, and deployment of the experimental payload.

Thank you!

the notre dame rocketry teamdaniellavelle.com/cdr_pres.pdfflight # conditions raven apogee...

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