Final Design Presentation (1) (1)
- 1. AGGIELOOP Final Design Presentation Presented by: Tadeo Huerta, Craig Medlin, Morgan O’Neil, Tyler Paschal, and Nathan Stephens 1
- 2. Introduction Needs Statement “Provide a design for a reusable capsule that will safely, reliably, and comfortably transport up to 30 passengers through a low pressure tube up to – and down from – high speeds with minimal losses due to drag and friction. This system will provide maximum passenger throughput with minimal downtime between departures.” About Our Pod • Aggieloop-001 “Basilisk” • Semi-monocoque aluminum construction with a carbon fiber outer skin • Air bearing levitation system • Transports payloads at relatively high speeds efficiently and safely What makes us unique? • Proven Industry Components • Battery Cooling System • Flexible Design 2
- 3. Aerodynamics & Structures Shell • CFRP • Profile optimized using CFD • Structural support, aerodynamic efficiency, and light weight Structure • 6061-T6 Aluminum • Semi-monocoque construction • MATLAB optimization • Structural support of a solid body, light weight, conforms to shell Ducting • Sheet steel • Housing for fan/compressor at full scale • Reduces air pressure at nose • Added diffuser for increase in fan/compressor performance CFRP Shell 3
- 4. Aerodynamics & Structures 6061-T6 Aluminum Semi- monocoque (Preliminary) Shell • CFRP • Profile optimized using CFD • Structural support, aerodynamic efficiency, and light weight Structure • 6061-T6 Aluminum • Semi-monocoque construction • MATLAB optimization • Structural support of a solid body, light weight, conforms to shell Ducting • Sheet steel • Housing for fan/compressor at full scale • Reduces air pressure at nose • Added diffuser for increase in fan/compressor performance 4
- 5. Aerodynamics & Structures Air Bypass Ducting Shell • CFRP • Profile optimized using CFD • Structural support, aerodynamic efficiency, and light weight Structure • 6061-T6 Aluminum • Semi-monocoque construction • MATLAB optimization • Structural support of a solid body, light weight, conforms to shell Ducting • Sheet steel • Housing for fan/compressor at full scale • Reduces air pressure at nose • Added diffuser for increase in fan/compressor performance 5
- 6. • Acceleration – Pod pusher for acceleration to test speeds • Air Bearings – Near Frictionless interface with tube – No need for thrust – Allows for longest time at test speed without providing thrust Levitation 6 Pusher Interface and Compressed Air Tanks
- 7. • Acceleration – Pod pusher for acceleration to test speeds • Air Bearings – Near Frictionless interface with tube – No need for thrust – Allows for longest time at test speed without providing thrust Levitation Isometric view of Sled 7
- 8. Levitation AIRFLOAT Air Skids: • Optimized for smooth surfaces • Varied and frequent use in industry • Low air tank capacity and airflow requirement • Utilizes pressurized air • Vertical self-regulation 12” Air skids (AIRFLOAT) 8
- 9. Horizontal Stability wheels • Guides the pod along the rail • Keeps in constant contact with the rail • Is dampened to avoid other parts of pod coming into contact with the rail • Springs only exert minimal pressure on the rail Stability Front view of wheels on rail Isometric view of wheels on rail 9
- 10. High capacity wheels • Solid • Deployable • Powered by a 5 HP AC Motor Disc Brakes • Adjustable brakes for constant braking • High friction on concrete on the outside of the aluminum track Taxiing and Braking Notional Wheel and Brake design 10 Axle Brakes • Backup for Disk Brakes Deployment • Spring and diaphragm pneumatic actuators that raise when filled with air • Use of two solenoids to fill and dump diaphragm provides redundancy
- 11. Controls • Control Unit – Single Board Computer – Embedded Linux • CAN Bus – Reliable – Industry Proven • “End Node” Module provides universal interface • SpaceX Network – Telemetry 11 “End Node” Board Designed by Aggieloop
- 12. Controls • Safe-Stop – In case of any of the following: • Tube anomaly • Excessive vibration • Excessive acceleration • Loss of air bearing pressure • Operator input – Stop command will be issued • Deploy wheels, apply brakes at full power • If brakes fail, engage emergency brake 12 Conceptual GUI Mockup
- 13. Sensor Locations 13Potential Exterior Sensor Locations
- 14. Sensor Locations 14 Notional Battery Temperature Sensor Location
- 15. Sensor Locations 15 Prototypical Internal Sensor Locations
- 16. Energy 16 Li-Po Battery Selection • High energy density • Ease of overall maintenance • Fewer cells than Lithium-Ion • Hard-case pack filled with fire-safe material
- 17. Energy High Voltage Module • Main source of power • 4 modules on board Module Specifications ● 60 VDC ● 285 Ah ● 2.5 kWh ● 55 cells Pack Integration ● Four modules wired in series ● Provides enough power to run all components through testing procedures, and during the actual run ● Refrigeration system to operate in vacuum pressure to cool batteries Module of 55 batteries 17
- 18. Energy 12 V Battery 12V Module Specifications ● 12 VDC ● 15 Ah ● 180 kWh Pack Integration • Redundant power supply for the control systems • Location isolated from the main battery bank • Enough power to activate the pod stop command 18
- 19. Cooling Purpose • Provides cooling for high energy batteries • Operates in vacuum pressures • Utilizes air from air bearings for cooling medium Plate Heat Exchanger • Efficient cooling in low volume device • Thin plates optimize surface area • Multiple plates maximizes volume flow 19 Plate Heat Exchanger
- 20. Cabin Payload • Simulated weight of 8 people and life support systems for small scale • Can simulate this weight with experimental equipment – Have the capability of running pod with pressurized, or low pressure equipment on board Life Support • Air conditioning, CO2 scrubber, backup air supply • Backup lights – Battery powered, and glow strips for redundancy • Added door for access to cabin to place sensors, ballast, and experimental equipment 20
- 21. Cabin Cabin External RenderingCabin Cross Section 21
- 22. Conclusion Aggieloop-001 "Basilisk" – Cost: $40,000 – Length: 16’ – Weight: 2500 pounds – Structurally sound – Flexible design – Aerodynamically efficient – Sufficient power supply – On-board experimentation 22 Why We Are Here • To pursue our passion • Make a contribution • Change the world
- 24. Flow Optimization Solidworks CFD simulations – Simulated pod in tube, with air flowing around – Low drag at 0.02 psi in tube (~1.5 lb) – Internal (ducting) and external simulations 24 External Flow Simulation Internal Flow Simulation
- 25. MATLAB Optimization Method • Dependent variables: Stresses on structure • Independent Variables: Member cross sectional area; Components in pod • Control Variables: Quantity of structural members • Grid based optimization of all combinations of members 25 x Approach • Utilizes solid mechanics principles for structural analysis • Purpose: Optimize quantity of structural members used in semi- monocoque
- 26. Levitation Air Bearing Cross Sectional View Diagram 26 x
- 27. Levitation Comparison 27 Air Bearings (Air Float) Magnetic Levitation (Arx-Pax) Lift Capacity (per pair) 6,000 lb 243 lb Cost (per pair) $2,250 $10,000 Power Consumption (W) Minimal (Power draw from regulators) 4400 Number of Pairs 2 11 x
- 28. Secondary Movement • Suspension – Inspired by motorsport • Pushrod actuated suspension mounted on linear actuators • Motor for taxiing – 5hp AC motor • Cheaper than equivalent DC motor • Lighter than equivalent DC motor – Connected to wheels via CV axles 28 x
- 29. Wheels • Pistons use air pressure to raise the wheels –In case of pressure loss wheels will automatically deploy with assistance from springs • Wheels will be retracted once the air bearings take the load of the pod • There will be a pair of solenoids on each line to the pistons –Controls the airflow to the pistons, allows for fault tolerance • Once the wheels are deployed the brakes will engage 29 x
- 30. Controls 30 Controller System Network Flow Chart
- 31. Sensors 31 •High tech laser-retroreflective sensor •Contains laser of class 2 •30 micro-second response time •Sensing range is 10 meters •Retro-reflectivity will keep track of the pod’s position •Remaining pod length can be calculated •Location is top front of the pod DK_LAS-54/76/110/124 Contrast Sensor GP2Y0E02A Orientation Sensor •Measures distance using a CMOS image sensor and IR-LED •Depending on detected distance it will output a corresponding voltage •Location will be along side each exterior corner of the pod •All four sensor’s data must be equal to ensure correct orientation else breaks will be deployed x
- 32. Sensors 32 BMA280 Accelerators •2mm X 2mm •Triaxial •Low-g acceleration sensor •Contains digital interfaces •Ability to sense tilt, motion, and shock •Location on bottom of passenger compartment BME280 Pressure/Temperature/Humidity •High linearity •High accuracy •Long term stability •Absolute barometric pressure sensor- exceptionally high accuracy •Measures ambient temperature at very low noise and high resolution x
- 33. Sensors 33 ADXRS453 Attitude Sensor •Complete rate gyroscope •300 degree per second angular rate sensing •Ultrahigh vibration rejection •Internal temperature compensation •SPI Digital output with 16-bit data word •Consistently checks for angular rotation of the pod •If out of range motion detected the wheels will be deployed LDT0-028K Vibration Sensor •Contains Polymer film •Screen-printed electrodes •Two crimped contracts •High voltage generated if film is displaced from neutral axis •Vital component of pod’s stability detection •Reports stable/unstable state •Location includes forward and backward interior of the pod x
- 34. Energy 34 Power Consumption vs Battery Capacity
- 35. Energy Wiring Schematic High Voltage Pack Specifications ● 240 VDC ● 285 Ah ● 10 kWh ● 220 cells Battery Control Module ● Balances charging/discharging of cells Electrical Distribution System ● Transmits energy to Pod components 35
- 36. Cabin Figures • Seat Pitch – 48 in • Seat Width – 22 in • Ceiling Height – 66 in • Estimated Full Scale Mass – Carry on per person – 18 lbs – Seats – 15 lbs each – People 120 lbs (5th percentile) – 220 lbs (95th percentile) – Estimated mass of life support systems – 750 lbs – Small scale estimated total mass – 870 lbs 36 • Cabin Pressure - 11.34 pisa • Cabin Temp - 72 F • Cabin Humidity Level - 0.12% • Partial pressure CO2 after journey - 0.11 psia x
- 37. Full Scale Cabin Safety • Fire – 3m Novec 1230 fire protection fluid • Nontoxic to the environment • Faster than CO2 • Air – Emergency Air Required • 10.57 lbs (21 % O2, 79% N2/H) • Stored in composite pressure vessels – Loss of Cabin pressure • 10.17 psi (Stable Cabin pressure: 11.4 psi) • Drop down masks – High CO2 content • Flood Style air replacement 37 • Emergency Door Opening Procedure – Analog Gauge Displays pressure difference between the cabin and the tube • In case of total power loss • Easily readable – Mechanical system only allows door to open when there is a safe pressure differential • Emergency Lighting – Battery powered in case of total power loss – Afterglow phosphor based material • 30 hours of luminescence • Incase battery lights are out x
- 38. Full Scale Safety • Total power loss – Backup battery ensures the on board computer can still bring the pod to a controlled stop. • Atmosphere introduction in tube – Pod will naturally begin to slow down due to higher air pressure. T – he on board computer will then bring the pod to a controlled stop • Pod becomes stuck in tube – Reintroduce atmosphere to the tube, enter the tube – Determine if pod can be moved out of tube under its own power – Remove pod from tube • Redundant systems – Redundant power supply – Redundant systems for deploying the wheels – Redundant life support systems – Redundant systems for slowing down the pod 38 x
Editor's Notes
- #3: Teddy 3.5 min
- #4: Craig (Aero, CFD) & Tyler (Structures, matlab) 3 min
- #5: Tyler & Craig 2.5 min
- #7: Ryan Coelho 2.5
- #8: Ryan Coelho 2.5
- #12: Craig 2 min
- #13: Craig 2 min
- #17: tyler (cooling) and nathan (overview) 2 min
- #19: tyler and nathan 1.5
- #20: tyler and nathan 1.5
- #21: Nathan 2 min In order to maintain the ability to scale our pod directly to full scale, we knew that we were going to have a cabin on board our small scale pod from day 1. And as the passenger systems team lead, I was in charge of making sure we had a design for the best cabin possible. This meant ensuring that our cabin not only has to provide people with comfort, it has to keep the passengers safe at all times. Since people are not going to be riding in the small scale pods, we as a subteam decided that the best way to design the cabin would be to design the full scale and then scale the design down to the small scale size. When tackling this design, we first wanted to be comfortable so we started with the chairs. We then turned to the commercial airline industry in order to find out what their average seat pitch, seat width, and ceiling height was. We used these numbers as a benchmark for us to beat. One of the most common complaints with airlines is that there is not enough room for you to be comfortable. So using the industry average seat pitch and seat width as a baseline, we went a couple inches larger on each in order to ensure the comfort of the passengers. Another thing we did that was inspired by commercial airlines is store all the life support equipment under the floor of the cabin. This allows for maximum efficient use of the space while keeping the life support systems in the cabin. Once we scaled it down, we noticed that in order to simulate the people, and life support systems, we would have a system weight around 850 pounds, roughly 750 pounds of which would be ballast. Instead of sending our pod down the tube with essentially 850 pounds of ballast, we could use that weight to do something productive. We could essentially sell room on our pod as a test bed for experiments some companies would like to run. Instead of having 850 pounds doing nothing, why not put that weight to use?
- #22: Nathan 2.5
- #23: Teddy 3 min
- #24: Teddy 3 min
- #30: someone 3.5
- #31: Craig 2 min
- #32: someone 3.5
- #33: someone 3.5
- #34: someone 3.5
- #36: tyler (cooling) and nathan (overview) 2 min
- #38: someone 3.5
- #39: someone 3.5