Preliminary Design Review Agenda Overall Vehicle Design Recovery - - PowerPoint PPT Presentation

Preliminary Design Review

Agenda

• Overall Vehicle Design
• Stability
• Motor Selection
• Thrust to Weight Ratio
• Vehicle Subsystem

Design

• Recovery Design
• Payload Design
• Requirement

Compliance

• Education
• Timeline
• Next Steps

Vehicle Dimensions

Vehicle Sub Section Length (Inches) (1) Nose Cone 20 (2) Payload Bay 18 (3) Main Parachute Bay 18 (4) Electronics Bay 9* (5) Drogue Chute Bay 15 (6) Lower Body Assembly 30

• Universal Outer Diameter- 5 inches
• Universal Inner Diameter- 4.842 inches
• Thickness- 0.079 inches
• Nose Cone Shape- Ogive

*Internal coupler

3 2 4 1 5 6

Vehicle Design – Nosecone

• Original Design
• 5-inch diameter
• Filament wound fiberglass
• 5:1 Von Karman style
• Metal tipped
• New Design
• 5:1 Von Karman --> 4:1 Ogive style
• Justification
• More cost effective
• Reduced the length
• Reduced weight by 5 oz

Vehicle Design – Payload Bay

• Design
• G12 Filament Wound Fiberglass
• 5 inches diameter
• 18 inches length
• Connected to nosecone via 4 shear pins
• Attached to coupler that houses

the CO2 deployment system

• 2 rail system and T frame

holds payload in place

Vehicle Design – Main Parachute Bay

• G12 Filament Wound Fiberglass
• 5 inch outer diameter
• Stores 80 inch Parachute
• ¼" quick link connected to the welded eye bolt
• SkyAngleCert-3
• Rip stop nylon
• ½ Inch tubular nylon shock cord
• attached to coupler and electronics bay
• Bears brunt of shock forces during separation

Vehicle Design – Electronics Bay

• G12 Filament Wound Fiberglass
• 5" tube coupler
• 5" coupler bulkheads
• Coupler retained using two threaded steel

rods

• Outer 1 inch ring allows easy access to

the arming switches.

• Eye bolt on bulkhead have the parachute

and shock cord attached.

Vehicle Design – Lower Body Assembly

• Drogue Chute Bay
• Fins
• Motor Mount
• G12 Filament Wound Fiberglass
• 5 inch diameter

Vehicle Design – Drogue Chute Bay

• Built into the Lower Body Assembly
• Attached to the aft section of the electronics bay
• Stores 24 inch Parachute
• Connected via forged eye bolt
• ¼ inch quick link
• Easy installation and removal of parachute.
• ½" Tubular Kevlar shock cord

Vehicle Design – Motor Mount

• Built into the Lower Body Assembly
• 3 Fiberglass centering rings
• G12 Filament Wound Fiberglass motortube
• Epoxied to lower body tube with fins
• Greater strength and retention
• Third centering ring is 1 inch from the back
• Accommodates motor retainer
• Better secures fins

Vehicle Design - Fins

Characteristics

• 0.1875-inch sheet of G12 fiberglass
• 4 symmetrical trapezoidal fins
• 11-inch root chord
• 3-inch tip chord
• 6-inch sweep length
• 4.5 inches height

Justification

• Stability margin of 2.53 calibers
• Simulated maximum velocity is 1424ft/s
• Good balance between stability and risk
• f weather cocking
• Low risk of fins breaking during recovery

Material Overview

• Fiberglass
• Light weight
• Durable
• Readily available
• Easy to work with
• Steel
• Very Durable
• Cheap
• Easy to find
• Plywood
• Very light weight
• Easy to work with
• Kevlar
• Extremely Durable
• Flexable
• Nylon
• Very flexible
• Easy to deploy
• Easily folds into bays

Stability Margin

• Static Stability: 2.53
• Center of Pressure: 65.91 in
• Center of Gravity: 53.266 in

Motor Selection

• Motor: Aerotech K1000T-P
• Apogee: 5355 ft
• Max Velocity: 660 ft/s
• Burn Time: 2.47 s
• Total Flight Time: 118 s

Thrust to Weight/Rail Exit

• Thrust to Weight Ratio: 9:1
• Rail Exit Velocity: 69.5 ft/s
• Distance to Stable Velocity: 3.5 ft
• Stability Caliber: 2.53
• Rail Choice: 8 ft

Recovery Subsystem

• Two StratologgerCF altimeters
• Two new 9V batteries
• Four Blast caps with 2g of black powder
• Two bulkheads and two threaded rods
• Lower half contains the 32in drogue

parachute, upper half contains the 80 in main parachute

• Sections are tethered with tubular nylon

and a nonslip knot

Recovery Subsystem

• On launch rail altimeters are keyed
• n
• At apogee the main altimeter

ignites a lower ejection charge, ejecting the drogue parachute

• At 700 feet above ground the main

altimeter ignites an upper ejection charge, ejecting the main parachute

• The backup altimeter ignites its

lower ejection charge one second after apogee

• The backup altimeter ignites its

upper ejection charge at 650 feet above the ground

Drift Calculations

With a simulated crosswind of zero mph and zero standard deviation in wind velocity, the response lateral drift for the current model and expected motor is less than 8 feet from the launch rod position when modeled as launching vertical at a ninety-degree angle to the ground.

Drift Calculations cont.

Trial wind velocity Nominal Drift Distance 0 mph crosswind 8 feet 5 mph crosswind 460 feet 10 mph crosswind 1000 feet 15 mph crosswind 1500 feet 20 mph crosswind 2232feet

Payload Subsystem

• CO2 nosecone

deployment

• Autonomous deployment
• f rover and solar panels
• Radio transceiver
• 433 MHz
• Electric coupling from

rover to CO2 deployment circuit

• GPS/IMU positioning

system

• Local and remote data

logging

Rover Design

• Geared wheel deployment
• Four wheel drive
• Sliding solar panel system
• GPS/IMU distance tracking
• Operates independent of orientation
• Can drive upside down or right side up
• IMU to detect orientation of rover

Rover Wheel Design

Gear Wheel Design

• Rests easily on the rack and pinion in the

payload bay.

• Determined to have sufficient traction on

the terrain of the launch field.

• Majority of team supported gears for

wheels.

Pure Wheel Design

• Provides traction on the terrain of the

launch field.

• Harder to find off the shelf wheels with

correct dimensions of the rover.

• Less supported by the team for use.

Initial Solar Panel Design

Solenoid Deployed Design

• Spring loaded tray with a solenoid release

mechanism.

• Solenoid requires lots of power which would

require more power.

• Bad because the solenoid is large and

decreases ground clearance.

• Bad: springs are passive and risks not

deploying. Clam Shell Design

• Three different possibilities for this route: folding
• ut in an X- shape, folding out in a diamond

shape, and folding out off of itself.

• Risks possible issues with having enough ground

clearance.

• Issue becomes that springs are passive which

causes risk for not being deployed.

• Six 1.378" x 1.654" x 0.079" panels
• Output 223 mW at 6.3 V
• Produced by IXYS Solar as a part of

their IXOLAR series

• Deployed with a HiTec Ultra-Nano

Servo

• 11.11 oz/in of torque
• Total deployed surface area of 6.838
• sq. in.

Solar Panel Design

Initial Payload Deployment Designs

Solenoid Latch Rotary Latch

• Rotary disk actuates pins to free the

nosecone

• Solves power issues from solenoid system
• Does not solve issues with mass of

nosecone or binding

• Four solenoids actuate to free the nosecone
• Power requirements for solenoids would

require additional power supply

• Rover may have insufficient torque to move

nosecone

• Nosecone could bind as it extracted

Payload Deployment

• Peregrine CO2 ejection system to deploy

nosecone

• Nosecone attached to payload bay with

shear pins

• Rover deploys itself after nosecone has

been ejected.

• Alleviates risk of nose mass or binding

preventing deployment of the rover.

Payload Electronics

• Battery and control electronics all mounted on the rover
• GPS
• IMU
• 5 servos
• 2S LiPoBattery
• Transceiver
• Electrical coupling to CO2 e-match triggering system
• Spring-loaded pogo pins
• Simply drive away rover to 'release' from system

Payload Electronics

• ATMega32U2 Development Board
• Breadboard compatible
• 8MHz, 3.3V Operation

Payload Electronics

• AX5043 Development Board
• 433MHz 1/4λ monopole antenna
• Breadboard compatible

Payload Electronics

• SAM-M8Q-O Development Board
• GPS chip and antenna all in one
• Integrated module
• Breadboard compatible

Distance Evaluation System

• GPS
• Low update rate
• Positional accuracy only 2.5m
• Can safely overshoot minimum required

distance

• IMU
• High update rate
• Use accelerometer and gyroscope to evaluate

distance

• Error builds up over time
• Combine
• Reduce total error
• Kalman Filter Approach

Requirement Compliance

• UT Rocketry team has created a plan to follow all NASA USLI guidelines. All

systems have team leaders that have read the NASA handbook and understand the requirements.

• After Team Leads have demonstrated they are competent in their area, they

create checklists that all team members must abide by.

• Many major systems pertaining to flight safety and stability have redundant

checks and hardware to ensure NASA requirements are met.

Education

• Boy Scouts Rocket Camp
• 317 Youth (K-6th)
• Assisted kids in the building and launching of kits
• Helped adult educators
• Hallow-engineering
• 35 Youth (K –8th)
• Helped local kids launch balloon rockets

Education (cont.)

• Future Events
• Clay High School
• 9th-12th grade
• Present to upper level physics classes
• Launch a rocket with a F motor
• Boy Scout Troops in Akron, Ohio
• 5th-12th grade
• Space Exploration merit badge

Next Steps

• Subscale construction to begin following PDR
• Subscale test launch:
• December 2: Cedarville, OH
• Build prototype rover to test deployment and mobility
• Ground tests of payload deployment to confirm CO2 canister values
• GPS/IMU accuracy testing
• Transmission range testing