preliminary design review · launch vehicle dimensions • total length 108in • airframe od...
TRANSCRIPT
Preliminary Design Review
California State University, Long Beach USLI
November 13th, 2017
System Overview
Launch Vehicle Dimensions
• Total Length 108in
• Airframe OD 6.17in. ID 6.00in.
• Couplers OD 5.998in. ID 5.775in.
• Motor Mount 75mm
• Centering Ring Thickness 0.2 in
Material Selection - Airframe, Nose Cone & Couplers
• Significantly stronger than blue tube
• Much cheaper than carbon fiber
• More environmentally resistant than blue tube
• Low thermal and electrical conductivity
Fiberglass
Material Selection - Fins
Carbon Fiber
• Highest yield strength
• Highest strength to weight
• Great environmental
resistance
• Affordable for fins
Material Selection - Bulkheads & Centering Rings
• Stronger than wood
• Inexpensive
• Easily manufactured
• Adds stability to coupler
sections
Aluminum
Material Selection - Miscellaneous
• Avionics tray will be 3D
printed using ABS material
• Epoxy for fin and centering
ring attachment is Aeropoxy
Light epoxy
Motor Selection
• 75mm Cesaroni 4263-L1350-CS
• Provides sufficient thrust to reach an apogee well over a mile
Stability
• From the tip of the nose cone
• Center of Gravity (CG)=68.73in
• Center of Pressure (CP)=85.05in
• Stability Margin=(85.05-68.73)/6.17in=2.64 cal
Flight Simulations
• Total Mass-42.0lbs
• Projected Apogee- 5467 ft
• Thrust-to-weight ratio-7.21
• Velocity off rod -66.9ft/s
Recovery SystemAltimeter
Vendor Model Cost (1-5)
Weight (1-5)
Features (1-5)
Integration (1-5)
Total
Eggtimer Eggtimer Quark
5 5 1 2 13
PerfectFlite Stratologger CF
4 4 3 4 15
MissileWorks
RCC2+ 4 4 3 3 14
MissileWorks
RCC3 Sport 3 2 4 4 13
Adept AltS2-50k 2 2 2 3 9
Altus Metrum
Easy Mega 1 3 5 4 13
Recovery System (cont.)GPS Unit Comparison
Vendor Model Cost (1-5)
Weight (1-5)
Dimensions (1-5)
Integration (1-5)
Total
Transolve BeepX 5 2 1 2 10
Eggtimer Eggfinder 4 4 1 2 11
BigRedBee
BRB900 TX/RX
3 4 3 4 14
Altus Metrum
TeleMetrum 3 4 3 3 13
Altus Metrum
TeleMega 2 4 1 4 11
Recovery System (cont.)
• 13” Coupler Piece
• U-Bolt - 1,075 lb Maximum Capacity (Nylon Harness)
• Primary and Backup Altimeters
• BRB900 GPS Tracker
• Rotary Switch
Recovery System (cont.)
Type of Parachute
Parachute Size and Model Location Relative Descent Velocity (fps)
Drogue Parachute
20" FC TARC Low and Mid Power Parachute
Nose Cone + Payload Bay Aft End
92.99
Main Parachute 84" FC Iris Ultra Standard Parachute Propulsion Bay Forward End 17.80
Recovery System (cont.)
Wind Speed (mph)
Wind Speed (fps) Drogue Drift (ft)
Main Drift (ft) Total Drift (ft)
0 0 0 0 0
5 7.33335 376.9589526
205.9929775 582.9519301
10 14.6667 753.9179052
411.985955 1165.90386
15 22.00005 1130.876858
617.9789326 1748.85579
20 29.3334 1507.83581 823.9719101 2331.80772
Recovery System (cont.)Kinetic Energy for Each Independent Section Upon Landing
Section Weight (lb) Mass (slugs) Descent Velocity (ft/s) Kinetic Energy (lb-ft)
Payload Bay 13.879 0.431373199 17.80 68.33814219
Avionics Bay (After Event 2)
4.769 0.148225289 17.80 23.48185028
Propulsion Bay 12.983 0.403524623 17.80 63.92637078
Recovery System (cont.)
Rover
Rover Overview
• Ground clearance
• Payload Space
• Distance
• Solar panel
Rover: Design Considerations
• Cylindrical Rover• Stability, complexity, volume
efficiency
• Triangular• Able to deploy in multiple
orientations.• More possibilities of failure.
• Rectangular• Wheg wheels
• Simple design
Rover: Design Choice
• Triangular• Able to deploy from any
orientation.
• Bogie system
• Gearbox
Rover: Design Choice
• Triangular
• Maximizes available space in
rocket.
• Houses all electronics inside the
body.
Rover Controls and Electronics
• Controller• Arduino Nano• Motorshield
• Sensors• Inertial Measurement Unit (IMU) • Rangefinder
• Control• Yaw Suppression• Obstacle Avoidance
Rover Deployment Mechanism (RDM)
RDM SummaryPurpose: Remotely deploy the rover from the internal structure of the launch vehicle.
Design Choice:
● Single motor● One threaded rod and two non-threaded rods● Load is driven along threaded rod through a matching
threaded nut
Mechanical/Hardware
● Rotary to linear system for load translation○ Motor attached to threaded rod○ Threaded nuts attached to the rover
● Bulkhead with threaded nut
Electronics/ Control● Remotely activate the system
○ 2.4GHz Digital Transmitter/Receiver
● Motor control○ Arduino Nano
Microcontroller○ L298N H-Bridge○ 11.1 V LiPo Battery
● Provide motor feedback○ rotary encoder
RDM Schematics
Remote rover deployment switch initiated
Rocket landsElectric motor spins the threaded rod in the loosening direction
The nose cone translates along the rod and detaches.
The rover continues to translate, and pushes the nose cone away from the airframe.
The rover falls off the rod and initializes the system.
Airbrake Summary
• Main Goal: Ensure that the rocket achieves target apogee by correcting upward drift velocity after engine cutout.
• Mechanics: airbrake flaps are deployed by use of a linear actuator.
• Control: triggering the actuation of the flaps to maintain target velocity.
Airbrake mechanics
• A linear actuator with a 2” stroke will be used to deploy the flaps from the rocket.
• The actuator will pull up causing the linkage arms to straighten, deploying the flaps.
• 4 flaps are used to maximize drag without compromising the structural integrity of the rocket.
Air Brake Control
• Electronics• 2” Stroke electric linear actuator• Arduino Nano microcontroller
• Sensors• Pitot Tube Airspeed Sensor• BMP280 Barometer• 6 DOF IMU
• Control• Correct for error in velocity• Modeling of system to determine timing, duration, and
deflection of flaps• Closed versus open-loop system
Significant Failure Mode - Launch Vehicle
● Tail Fins shear off during flight○ Fins are not properly secured to airframe○ Rocket takes unpredictable flight path○ Ensure adhesive used is strong enough to handle force of flight. Check
adhesive for cracks before launch.● Fins not properly aligned
○ Fins not assembled correctly○ Rocket spins uncontrollably○ Follow proper procedure when assembling fins
● Motor centering ring fails○ Adhesive not properly applied to centring ring○ Motor launch through the rocket○ Construction procedures are followed for applying adhesive
Significant Failure Mode - Recovery
● Parachute does not deploy○ Parachute gets tangled around rocket○ Rocket will fall to ground at high velocity○ Parachute will be integrated in a was to reduce risk of getting tangled
● Parachute has rip○ Parachute gets ripped while deploying○ Rocket descend to quick and get damaged upon impact○ Team members will be careful during packaging of parachute
● Altimeter failure○ Faultily altimeter○ Parachute will not deploy○ Use two altimeter for redundancy
Significant Failure Mode - Airbrakes
● Structural damage to airbrake system during launch○ Material of airbrake not strong enough○ Airbrakes will not deploy or become damaged○ Verify through testing that airbrake can handle force of flight
● Airbrakes do not deploy at desired altitude○ Programming failure○ Rocket will not make desired altitude○ Test airbrakes programming during subscale launch
● Airbrake flaps fly off during flight○ Flaps made not to handle force of launch○ Rocket become unstable○ Verify through testing flaps can handle force of flight
Significant Failure Mode - Rover
● Rover damaged during landing○ Impact of landing more than expected○ Rover becomes inoperable○ Make sure rover is secure in place before launch and test to ensure it can handle
force of landing● Rover damaged during flight
○ Rover not secure in place○ Rover becomes damaged and inoperable○ Ensure rover is secure put in the rocket
● Rover gets stuck on rock○ Rover not capable of handling terrain○ Rover gets stuck and unable to make distance requirement○ Design rover to handle all terrains and verify that through testing
Significant Failure Mode - RDM
● RDM does not deploy when activated○ Programing failure○ Rover will not deploy○ Verify that programing will act as desired through testing
● RDM deploys during flight○ Electronic failure○ Nose cone opens up during flight○ Ensure electronics work properly through testing
● RDM becomes damaged during flight○ RDM materials cannot handle force of launch○ RDM damaged and rover will not deploy○ Choose strong material that can handle the force of flight
Testing
● Wind tunnel○ Test drag force and drag coefficient of airbrake flaps
● Drop testing○ Test strength of components to ensure they can
handle forces of flight and landing● Programing and Electronic testing
○ Test all programs and electronics to ensure that they act in the way that they are supposed to
● Shock and Impact testing○ Test all components of launch vehicle to ensure that
they can handle the shock of the flight and the impact of landing
Project Plan
TimelineSubscale Launch in November, Full scale built by February, Full scale launch in March
Airbrake Timeline
Educational Engagement
Event Date Estimated Attendees
Girls Day at the Beach (1) 3/2017 100
Aerospace Rocket Symposium
9/7/2017 200
Girls Day at the Beach (2) 9/2017 200
Introduction to Engineering Presentations
11/2017 100
MAES Latinos in Engineering Bottle Rocketry
4/2018 60
High School Engineering Presentation
12/2018 500
TOTAL 1160
Budget-ExpensesSubteam Projected Expenses
RDM $178.84
Rover $553.58
Avionics $538.63
Recovery $517.10
Launch Vehicle $2,295
Airbrake $137.83
Business $8,670
Total $13,870.91
Budget-Income
Source Income
College of Engineering $4,200
AIAA - CSULB $1,500
Fundraisers $1,500
ASI Travel Grant $7,000
Sponserships $600
Total $14,800