GT Hyperloop Pod Final Design Briefing Presentation

1

Georgia Tech Hyperloop Team

Pod Final Design Briefing1/29/2016

Presenters: Sayan Roy

Khambrel SimpsonWalter Malchodi

Michael FoleyRohan Deshmukh

SpaceX Hyperloop Design Competition

2

Presentation Outline

• Team Management• Pod Top Level Design Summary• Pod Subsystem Design• Pod Engineering Budgets• Pod Performance Analysis• Cost & Risk Analysis• Logistics Plan

Michael Foley

Should this slide be removed, seems kind of an interruption to flow.

3

Team Design Objective

The objective of the Georgia Tech Hyperloop team is to design and prototype an innovative solution to the world’s growing hub-to-hub transportation requirements in a

cost-effective manner.

Compressor

Electric Motor

Payload

Space-Frame Truss

Air-bearings

Magnetic Brake

Aerobody

4

TEAM MANAGEMENT“Individual commitment to a group effort--that is what makes a team work, a company work, a society work,

a civilization work.” – Vince Lombardi

5

Team Structure & Objective

Project ManagementSayan Roy

Faculty AdvisorDr. Neil Weston

AerodynamicsWalter Malchodi

StructuresKhambrel Simpson

Systems Engineering

Rohan Deshmukh

Levitation System

Michael Foley

Electrical & Power Systems

Jude Nifong

Stability & Control

SystemsStephen Haley

Intent: design and receive funding to build a pod following design weekend

6

POD TOP LEVEL DESIGN

“Simplicity is the ultimate sophistication.” – Leonardo Da Vinci

7

Team Design Process

Define Requirem

ents

Preliminary Design

Test & Experime

nt

Analyze & Validate

Iterate

8

Design Requirements - Level 0

Objective Level 0 Requirement Traceability

DO-1

GT Hyperloop shall be designed to provide a half-

scaled testbed for high-speed transportation

Mission ObjectiveTo design a novel

solution to the world’s growing transportation

needs in a cost-effective manner.DO-2

GT Hyperloop shall provide insight into alternate and cost efficient modes of

transportation

9

Flight System Overview: Subsystem Breakdown

Hyperloop Pod

Stability & Control System

Directional control

Longitudinal Control

High-Speed Magnetic Braking System

Low-Speed Braking System

Navigation System

Telemetry

Measurement

Data Filtering

Electrical Power System

Controller

Batteries

Levitation System

Air Bearings

Compressor

Motor

Structures

Space-Frame

Aerodynamic Paneling

Payload

10

Flight System Overview: Selected Subsystem Designs

Hyperloop Pod

Stability & Control System

Directional control

Longitudinal Control

High-Speed Magnetic Braking System

Low-Speed Braking System

Navigation System

Telemetry

Measurement

Data Filtering

Electrical Power System

Controller

Batteries

Levitation System

Air Bearings

Compressor

Motor

Structures

Space-Frame


Payload

11

Pod Dimensions/Design Summary

• Pod Length: 255 inches (21.25 feet)• Max Pod Width: 42.2 inches (3.52 ft)• Max Pod Height: 46.2 inches (3.85 ft)

Front ViewSide View

Top ViewAerobody

Compressor

Air Bearings21.25 ft

3.52 ft

3.85 ft

12

POD SUBSYSTEM DESIGN

“Alone we can do so little, together we can do so much.”

– Hellen Keller

13

• Air Bearing system based on hovercraft design– Want to lift the pod with minimal air bearing size, and minimal airflow requirements– Also want to avoid supersonic flow, which complicates design analysis– Made use of Excel solver to optimize our system

Source: A. Bliault and L. Yun, Theory and Design of Air Cushion Craft

• Air directed around center plate, aimed back toward center

– Helps induce turbulence, reduces flow speed without losing lifting pressure

• t - 1.00”• h - 0.05”• Pc – 2.7 psi

Pod Subsystem Design: Levitation System

Air Cushion

t

h

𝑃𝑐 h=𝜌𝑎𝑣 𝑗2 𝑡 (1+cos𝜃)

14

Pod Subsystem Design: Levitation System - Air Bearings

• Attaches to the truss with 4 bolts on extrusion out of top surface• Air fed through center with size 3 NPT • Aluminum 6061-T6 construction• PTFE-Acetyl blend (e.g. Delrin) rimmed base to reduce friction on loss of compression• Bearing area: 10” x 15”

17.15” 12.15”

15

Pod Subsystem Design: Air-Compression System

• Compressor– Utilizing a pressure optimized fan from Hover Hawk– 32” Diameter, 10 lbf, capable of moving 27,000 cfm at 3000 RPM with 37 hp– Flow diameter reduced to 3” for piping to air bearings

• Electric Motor– Using a COTS 43.7 hp DC motor available from Thunderstruck Motors– Dedicated battery pack for only this motor.

16

Pod Subsystem Design: Air-Compression System

• Motor sits behind/under the compressor• Compressor is contained in aluminum ducting inlet in case of failure• Inlet provides structural support to truss

17

Pod Subsystem Design: Stability System

• Directional Control– Implemented with a damping system featuring wheels around the central I-beam

• Longitudinal Control– Each air bearing has an electrically controlled valve to modulate output airflow– Each air bearing measures the distance it is from the ground– Air bearing output is adjusted based on distance measurement

• Note that this active control is a complement to the passive control inherent in the air bearing design• Air bearing too near to ground implies that a decrease in output has a relatively small

corresponding decrease in distance• Air bearing too far from ground implies that an increase in output has a relatively

small corresponding increase in distance

18

Pod Subsystem Design: High Speed Braking System

• High-speed Magnetic Braking System– To brake, permanent magnetic linear eddy current brakes are moved into position about

the central I-beam• Goal is to maintain deceleration of 0.5g• For pod mass, estimated required braking force is 2670N

– Will use a custom-made braking system• Modular design of H2W Technologies magnetic brakes makes for flexible, cost-effective

customization• High accuracy not needed since braking force can be modulated by altering the magnets'

distance from the central I-beam

Magnet assembly diagram, property of H2W Technologies

19

Pod Subsystem Design: Low Speed Braking System

• Low-speed Braking System– This brake is engaged when the pod is traveling at a speed of about 20 mph, below these

speeds the magnetic brake does not provide enough braking force– To brake, the brake pads will be pressed against the surface of the horizontal guiding

wheels, thus using a friction force to slow the wheels and bring the pod to a safe and complete stop

Wheel with Low-speed Brake Assemblies shown interfacing with I-beam

20

SYSTEMS ENGINEERING BUDGETS

“The budget is not just a collection of numbers, but an expression of our values and aspirations”

– Jacob Lew

21

System Engineering Budget: Mass

Pod Components Confidence Level

Unit Count Mass Per Unit (kg) Contingency (%) CBE Mass (kg)

Passenger Seats 7 2 15 15% 34.5Skids 5 4 6 25% 30

Hyperloop Truss 7 1 96.2 15 % 111Suspensions Skid 5 4 3 25% 15

Aerodynamic Paneling 6 1 66.2 20% 79.4Fire Extinguishers 7 2 1.47 15% 3.39

Valves 4 4 2.5 30% 13Permanent Magnets 6 2 4 20% 9.6Magnet Suspensions 5 2 2 25% 5Directional Wheels 7 4 2.5 15% 11.5

Wheel Brake 6 4 2.5 20% 12Wheel Suspension 6 2 2 20% 4.8

Magnetic Brake Control (Servos) 7 2 2 15% 4.6

Wheel Control 6 2 0.2 20% 0.48Communication Unit 7 1 1.36 15% 1.56

Micro-controller 7 1 0.05 15% 0.058

Active Power Management 7 1 0.2 15% 0.23

Amplified Photodiode Array 7 2 0.5 15% 1.15

Temperature Sensors 7 2 0.2 15% 0.46

System Release Valves 7 6 1 15% 6.9Passengers 7 2 44 15% 101Skid Piping 4 1 10 30% 13

Compressor Power System 7 1 78 15% 89.7

Fan 7 1 6.8 15% 7.82Aluminum Inlet 6 1 16.6 20% 19.9

Fan Tunnel and T 6 1 7.2 20% 8.64Motor 7 1 105 15% 120

MEV Mass (kg) 705

CBE= Current Best Estimate Mass Limit (kg) 713

MEV= Maximum Expected Value Mass Margin (kg) 8.2

Confidence Level Contigency9 5.0%8 10%7 15%6 20%5 25%4 30%3 35%2 40%1 45%

705 kg = 1554 lb

22

System Engineering Budget: Power

Subsystem:Confidence

LevelUnit

Count Power (W)Contingency

(%)CBE Power

(W):

Compressor Motor 7 1 33000 15 37950

Servos 5 9 10 25 113

Microcontroller 7 1 5 15 5.75

Feedback Controllers 7 9 5 15 51.8

Network Access Panel 7 1 20 15 23

MEV Power

(W) 38140

23

POD PERFORMANCE ANALYSIS

“[Design is] not just what it looks like and feels like. Design is how it works”

– Steve Jobs

24

Pod Performance Analysis: Aerodynamics

• Aerodynamics within the tube are somewhat different that those in the standard earth atmosphere due to the low density of the gas, the most important factor being the potential for reduced drag.

• Aerodynamic performance is based mainly on:– pod geometry– pod speed– fluid properties– active flow control (levitation system)

25

Pod Performance Analysis: Aerodynamic Analysis Goals

• Aerodynamic shell analysis aids in decision making to achieve goals:– Minimize aerodynamic drag on the pod

• reduce flow separation• reduce wetted and cross sectional area• reduce turbulence and vorticity

– Minimize shell weight based on• appropriate structure• appropriate material

– Minimize cost based on:• appropriate material• appropriate construction process

26

Pod Performance Analysis: Aerobody Geometry and Simulation Parameters

• Aerobody geometry meets the following criteria:– Fits around the spaceframe with the goal of reducing aerodynamic drag by

increasing the radii of curvature seen by the flow– Removes from the flow many of the surfaces likely to cause turbulence– Incorporates an inlet at the front of the pod to intake air for use in levitation– Utilizes minimal length, reducing skin friction and total mass

• Simulations were run in ANSYS 16.1 Fluent for a half tube (with a symmetry plane) at the following conditions. A Transition-SST model was used to solve

– Static pressure in the tube: 9.0 psia – Pod velocity (inlet velocity): 202 mph, 109 mph, and 45 mph cases– Air bearing pressure: 2.7 psig – Compressor intake pressure: 0.0 psig– Temperature: 80.3 degrees °F

27

Pod Performance Analysis: Compressor Inlet Pressure Contours

•Compressor inlet static pressure contours (on the vertical symmetry plane):

– Greater pressure on underside of pod due to skids

– Pressure drag from nacelle

28

Pod Performance Analysis: Flow Simulation Results

• Force coefficients and flow visualization, at 202 mph

– CD= 1.06

– CL,air bearing= 8.67

– CL,pod= 0.091

• Flow out the front and sides of the air bearings interrupts flow caused by the forward motion of the pod– Causes large, turbulent vortices around sides of the pod, as well as a small amount

of reversed flow on the upper surface of the tail fairing– Contributes to very high drag coefficient, much of which can be attributed to the air

bearing flow effects• At 109 & 45 mph the drag coefficient increases to CD=1.23 & CD=2.6 respectively

– Caused by relative increase in the effects of the air bearings

29

Pod Performance Analysis: Vibrational

• Pod truss is subjected to modal vibrations simulated through ANSYS Software– Fixed supports at the air-bearing mountings, then vibrations are simulated– Frequencies for testing was a broad range with the most significant deformations from

11 to 31 Hz– Pod truss appears to deform to a maximum at the front (7.6 in), which in reality is

mitigated to a reasonable level by the installation of the fan– Based on the FEA, the pod should be able to withstand vibrations during any

operational caseMode Frequency

(Hz)Maximum

Deformation (in)

1 11.0 1.93

2 13.9 3.07

3 21.0 2.35

4 28.2 3.53

5 29.8 3.58

6 30.5 3.96

7 31.7 7.61

Mode 1 simulation resulting in a 1.9317 inches deformation

Mode 7 simulation resulting in a 7.6116 inches deformation

30

Pod Performance Analysis: Structural Design Case Initial Acceleration

• The fixed support was located at the pod pusher interface, and at the air bearings of the vehicle

• Components which contributed more than 2% of total vehicle weight were modeled as force vectors and applied to truss members

• Magnitudes of force vector were applied for the case of a 1.7 G ramped acceleration

Component Percent Total Mass

Passenger Seats 4.98%

Air Bearings 3.99%

Hyperloop Truss 16.0%

Aerodynamic Paneling 11.0%

Passengers 14.6%

Compressor Power System 13.0%

Steel Inlet 2.76%

Motor 17.4%

31

• Equivalent von Mises Stress is far below the Tensile Yield Strength of Aluminum Alloy 6061 - T6 of 40,000 psi.*

• Deflections are concentrated at passenger seating locations

• Gauge of Aluminum Tubing could be decreased due to large Margins of Safety

Pod Performance Analysis: Structural Design Case Initial Acceleration

Structural Design Case Initial Acceleration

Maximum absolute deformation in

the X-Axis3.2*10-3 in

Equivalent (Von Mises) Stress

4120 psi

*Source: Aerospace Specification Metals Inc. Al 6061 - T6

32

Pod Performance Analysis: Structural Design Case Nominal Deceleration

Structural Design Case Nominal Deceleration


the X-Axis2.7*10-3 in

Safety Factor 15 Max, 9.27 Min

● Additional Fixed support added at location of Permanent Magnet, and force magnitudes were set for 1.6 Gs. This is above maximum deceleration created by brake engagement

● Similar deformations to initial acceleration analysis● Safety Factor was calculated to be at minimum 9

therefore gauge of aluminum tubing could be decreased

33

Pod Performance Analysis: Structural Design Case End of Tube Off-Nominal Crash

• Fixed support placed on ends of 3 of 4 fan inlet members to represent off nominal condition

• Force Magnitudes were applied to the truss representing a 1.7 G Deceleration

• Von Mises stresses were far below Tensile Yield Strength of the Aluminum

• Majority of deformations occurred at the rear of the pod near battery attachments suggesting that this load should be evenly distributed to members in the rear of the truss system

Structural Design Case End of Tube Off-Nominal Crash


the X-Axis0.0102 in

Equivalent (Von Mises) Stress 1000. psi

34

Pod Trajectory Profile (Speed vs. Distance)

For the Trajectory Profile, we divided the flight into four regions. Each section had a unique force equation associated with it that was used to find the velocity and distance:

1. Initial Acceleration:

2. Coasting:

3. Magnetic Braking:

4. Mechanical Braking:

35

Pod Trajectory Profile (Speed vs. Distance)

Pod Trajectory

Speed (m/s)

Distance (m)

Magnetic Brake

Mechanical Brake

Coasting

Initial Acceleration

36

COST AND RISK ASSESSMENT

“Never was anything great achieved without danger ” – Niccolo Machiavelli

37

Engineering Unit Life Cycle Total Cost

System Cost ($FY16)

Engineering Unit $ 27,210

ManufacturingCosts $ 11,680

Testing Costs $ 8,280

Labor Costs $ 5,390

Total $ 52,570

The total life cycle cost falls well within the suggested cost cap of $100 K

38

Cost Breakdown by Subsystem for Engineering Unit

System Cost ($FY16)

Levitation System $ 3,890

Structure $ 9,350

Electrical Power System $ 10,020

Navigation $ 786

Stability and Controls $ 1,320

Payload $ 1,840

Total $ 27,210

39

Risk Identification

1. If the pod’s batteries were to overload, then the subsystems may shut down or fire may occur.

2. If the pod’s guide wheels were to fail, then the pod will no longer have lateral control, longitudinal control will be reduced, and guide rail may be damaged.

3. If the pod compressor were to fail, then the pod will loose levitation.

4. If the pod structure were to fail, stored energy will be released endangering the pod’s inhabitants and the Hyperloop itself.

Consequence

Battery Overload

Guide Wheel Failure

Compressor Failure

Structure Failure Likelihood

1 2 3 4 55 4 3 2

1Likelihood 1 – Remotely possible (less than 1%) 2 – Unlikely, but possible (1%-15%) 3 – Moderately likely (15%-50%) 4 – Likely (50%-85%) 5 – Almost certain (greater than 85%)

Consequence 1 – Minor performance degradation 2 – Some performance degradation or erosion of margin 3 – Significant margin erosion, system requirements barely met 4 – System requirements not met; design requirements threatened 5 – Extreme performance degradation, design requirements not met

40

Risk Mitigation

1. Battery Overload: control/avoid– Implementation of voltage & current regulators into control topology– Implementation of safety protocol for the handing of batteries during assembly and

manufacturing phase2. Guide Wheel Failure: control/avoid

– Redundant brake system– Emergency wheel lock technology– Failure scenario testing during systems integration phase

3. Compressor Failure: control/avoid– Implementation of regulators & valves into control topology– Testing using a full ground unit to identify issues post-integration

4. Structure Failure: avoid– Additional factors of safety– Thorough subsystem testing & analysis of truss components and aerobody

41

Production Schedule

Presentation Finalization

Presentation Presentation Practice

Design Weekend

Design Iteration and Procurement Plan FinalizationNew member recruitment and orientation

ProcurementStability and Control SystemLevitation SystemStructural ComponentsCompressor/Fan SystemTesting Rigs and PartsMargin

Learning Tools WorkshopSafetyManufacturing TechniquesSoftwareElectronicsMargin

42

Production Schedule(Cont.)

Procurement MarginSubsystem Assembly

Stability and Control SystemLevitation SystemStructural ComponentsCompressor/Fan

MarginSubsystem Testing Rig Assembly

Levitation System

MarginStructural

Subsystem Testing

Margin

Levitation System

Compressor/Fan

Stability and Control System

Structural Components

43

Production Schedule(Cont.)

Subsystem Testing MarginSystem Integration

System Testing

Transportation to Competition WeekendMargin

Competition Weekend

44

LOGISTICS PLAN

“The amateurs discuss tactics: the professionals discuss logistics”

– Napoleon Bonaparte

45

Design Comments on Scalability

• System Size – Scaled model of the pod based on two half-scale passengers– Size of pod does not scale linearly with added payload weight – Changing the tube length will impact the batteries required to power the levitation

system– Changing the tube diameter will affect the sizing of the pod as well as maximum

speed– Changing the pod size will affect the weight and thus the design of subsystems,

particularly the levitation system

• Cost– If our monetary resources are scaled, it will impact manufacturing costs the most

• Mitigation: reduce the pod size, which will lessen the this cost– The primary maintenance cost driver will be the replacement of air bearings if

unwanted friction occurs– Use of many COTS components reduce maintenance costs and down time

46

External Transport System

•Design based on a conventional hydraulic scissor lift system•Two scissor lift systems connected by an aluminum frame which sits on castor wheels will be sufficient to lift the pod weight for local transport

•Tie down straps will secure the pod in place during truck travel for longer distances•SpaceX provided crane will move the pod to and from the competition platforms

Source: http://bigboysgaragetoys.com/car-lifts/dannmar-cadet-6000xl-mid-rise-scissor-lift/

47

Stored Energy and Hazardous Materials

• Batteries

• Compressed air within the compressor, distribution system, and skids• Magnetic potential energy when any ferrous materials are in their vicinity• Lead in soldered components (lead-free solder will be used when possible)• Dust generated from occasional rubbing of the skids

Subsystem Capacity Material

Computer Systems 15Ah Lithium Ion

Actuators 16Ah Lithium Polymer

Compressor 100Ah LiFePO4

48

Vacuum Compatibility Assessment

• The pod will run at a tube pressure of 9 psi• Compressor is rated to operate at a tube pressure above 7 psi• No restriction on batteries at low pressure

– Issues may arise due to low rate of heat transfer if the batteries overheat– Mitigated through cooling system running over heat sink attached to battery

• Only the pressurized air distribution system, which provides air to the skids as well as for component cooling, is designed to maintain any pressure other than tube pressure

• All components are compatible with the chosen pressure

49

Concluding Remarks

•The Georgia Tech Hyperloop team plans to raise funds over design weekend and build a pod to compete in the Competition Weekend planned for Summer 2016

•The levitation system design is based on working hovercraft models•The pod features a lightweight and rigid space frame structure•The pod features both magnetic and mechanical braking systems•The pod is designed to feature many commercial off-the-shelf parts which will minimize costs as well as production time

•The pod design will be subject to further modeling and analysis•This pod design features an affordable cost for the production of a scale model

50

Questions?

Source: http://www.rita.dot.gov/sites/default/files/hyperloop.jpg

51

Backup Slides

52


Objective Level 1 Requirement Parent Requirement System

POD-1 Pod shall be designed to operate in a pressurized tube DO-1, DO-2

Pod

POD-2 Pod shall be designed to reach its final destination safely and efficiently DO-1, DO-2

POD-3 Pod shall be designed for ease in loading, launch, and unloading DO-1, DO-2

POD-4 Pod shall be able to receive data and commands throughout duration of operation DO-1, DO-2

POD-5 Pod shall fit within the cross-section provided within the SpaceX Hyperloop Track Specification DO-1, DO-2

LOOP-1 Test track shall be 1 mile long steel tube with a 6 foot outer diameter DO-1, DO-2

Hyperloop

LOOP-2 Test track shall be comprised of an aluminum track and rail mounted to a concrete fill bed DO-1, DO-2

LOOP-3 Test track shall implement a 12 foot long foam pit for emergency braking DO-1, DO-2

LOOP-4 Test track shall be designed to allow three types of levitation/suspension systems including wheels, air bearings, and magnetic levitation DO-1, DO-2

LOOP-5 Test track’s tube shall have an internal pressure between 0.02 – 14.7 psi DO-1, DO-2

LOOP-6 Test track shall not implement a thermal control system DO-1, DO-2

LOOP-7 Test track shall not be fitted with a structurally integrated propulsion system DO-1, DO-2

LOOP-8 Test track shall not implement an auxiliary electric rail DO-1, DO-2

LOOP-9 Test track shall be fitted with an Ethernet communication network DO-1, DO-2

LOOP-10 Test track shall be fitted with navigation aids via optical markings DO-1, DO-2

LOOP-11 Test track environment shall be regulated using a self-contained environments measurement system DO-1, DO-2

53


Objectives Parent RequirementLevel 2 Requirement

Subsystem Affected

TJ-1 POD-2, LOOP-1 Pod shall operate under the flight phases of acceleration, coast, and deceleration

TrajectoryTJ-2 POD-2, LOOP-1 Pod shall reach within 50 feet of the end of tube

TJ-3 POD-5, LOOP-1, LOOP-2

Pod shall travel efficiently between the ingress and egress areas and within the hyperloop

ST-1 POD-1, LOOP-5Pod shall be capable of surviving operation in a low-pressure environment throughout its lifetime

Structure

ST-2 POD-2 Pod shall have sufficient structural integrity and factor of safety ratingST-3 POD-1, LOOP-11 Pod shall incorporate a self-contained flight data recorder weighing less than 1 lbfST-4 POD-3, POD-5 Total mass of each pod shall not exceed 1,610 lbm

ST-5 POD-3, Pod shall be designed to be compatible with a crane for lifting

ST-6 POD-2 Pod shall be designed to carry a maximum payload weight of 200 lbsST-7 POD-1, POD-2 Pod shall be able to withstand acceleration of loads of at least 1.7g

TH-1 POD-1, LOOP-6Pod shall maintain a temperature that is within the operational range for the pod bus and payload of 60°F to 80°F

Thermal

TH-2 POD-1, LOOP-6 Pod shall implement a closed-loop thermal control systemL-1 POD-3 Pod shall be moveable at low speeds when not in operation

Levitation

L-2 LOOP-2, LOOP-4, LOOP-7

Pod shall implement air bearings for levitation

P-2 LOOP-2, LOOP-4, LOOP-5, LOOP-7

Pod shall implement an air-compression system

P-3 LOOP-2, LOOP-4, LOOP-7

Pod shall implement horizontal wheels for pod control

SCS-1 POD-2, LOOP-3, LOOP-4

Pod shall have a braking system capable of reducing speed to zero in a controlled fashion

SCSSCS-2 POD-2, POD-4, LOOP-9 Pod shall implement a continuous telemetry stream with a speed greater than 1 HzSCS-2 POD-2, POD-4, LOOP-9 Pod shall be able to safely stop autonomously through an external commandSCS-3 POD-2, LOOP-10 Pod shall implement a closed-loop navigation control systemEPS-1 POD-2, LOOP-8 Pod power system shall be sized to remain operational for the duration of operation

EPS

EPS-2 LOOP-8 Pod shall supply no less than 35 kW of power to pod subsystems

EPS-3 LOOP-8Pod subsystems shall have different power supplies, broken down based off voltage

EPS-4 LOOP-8 Pod shall implement a closed-loop power control systemCDH-1 POD-2, POD-4, LOOP-9 Pod shall have embedded systems for real-time control over telemetry data acquisition C&DHCOM-1 POD-2, POD-4, LOOP-9 Pod shall implement a continuous telemetry stream with a speed greater than 1 Hz Comms

54

Pod Subsystem Design: Navigation System

• Telemetry is achieved by interfacing sensors with a microcontroller– Concurrent data gathering

• Color sensors used to detect internal tube markings– Data read directly from pins– Separate RGB channels– Fast rise time so that even at high speeds markers are detected

• Inertial measurement unit (IMU) used to measure pod motion– Integral position measurement

• IMU data integrated to provide position• Note: results in integration drift over time

– Interval error correction• Color sensor positions treated as absolute references• Pod position error corrected at every internal tube marking

– Data is streamed in real-time at a minimum frequency of 1 Hz using the User Datagram Protocol via the SpaceX-provided Network Access Panel

• Navigation based on sensor data– Air bearings and braking controlled from microcontroller– Pod begins braking when the position measurement determines the deceleration

region has been entered• First stage braking is linear permanent magnet eddy current brakes• When a safe speed to deploy the clamping brakes has been reached, the

microcontroller issues the full stop command

Source: Texas Advanced Optoelectronic Solutions

55

Pod Subsystem Design: Command & Data Handling System

Command & Data Handling Control Schematic-Notes on locations of Sensors:• Thermistors on each microcontroller and each battery• Photo sensors are external to Pod• Pressure sensors are located in each air bearing, each pipe leading to air bearing

and compressor• Distance Sensor are located under each air bearing

C&DH Board

CommsADCS Board

Control InputControl Output

Compressor

Thermal

EPS

Battery 1

Battery 2

Battery 3

Battery 4

Braking

Navigation

IMU Photo Sensor

Thermistors

Wifi Receiver/Transmitter

Distance

Pressure

MAGMechanical

Valve Actuators

56

Pressure Sensor

Sensor Map and Location

56

Side View

Top View

Pressure Sensor (Above each Skid)

Pressure Sensor (Each Skid)

Not Listed:-Thermocouples-Measuring temperature of each microcontroller and each battery-Color Sensor

Pressure Sensor (External)

Distance Sensors (Each Skid)

SpaceX Network Access Panel

57

Pod Subsystem Design: Structural Space Frame

• Aluminum 6061-T6 chosen for its weldability, low density, and availability in a variety of tubing sizes

• Truss is designed to isolate high energy systems from human passengers

• Interior plates are not load bearing, instead dampen the passenger compartment from oscillating at low frequencies

• Truss is stiffened where motor, fan casing, fan duct, and batteries are located

Aluminum 6061 - T6Density 2700 kg/m^3

Ultimate Tensile Strength 310 MPa

Modulus of Elasticity 68.9 GPa

Poisson's Ratio 0.33

Pod Pusher Interface

58

Pod Subsystem Design: Payload

• Pod Payload is half scaled, capable of carrying two persons

• Each person is half sized and weighs 111.5 lbs

• Pod incorporates seats for each half scale person

59

Aerobody

•Reduced tube pressure reduces air density and pressures on the pod•Pod must still be aerodynamic to maintain the benefits of being in the tube•Unstressed aerodynamic shell designed to ensure that the pod can move smoothly through the air with as little pressure and friction drag as possible.

•Three main panels will each be constructed separately for ease of construction and modularity

–front cowling–main tube–tail cone

•Construction will use vacuum bagged quasi-isotropic laminate carbon fiber epoxy composite

•Negative mold on a positive form

60

Pod Performance Analysis: Thermal

• Electrical components– Digital components will have negative thermal contributions– Small actuators will also have negative thermal contributions– Battery internal resistance is attributed entirely to heat loss

• Assume internal resistance to be at worst 0.1A• At the operating speed, the current draw of 241.8A leads

to a heat loss of 24.18W

61

Pod Subsystem Design: Power System

• Provide each subsystem with its own battery to reduce inefficiencies from conversion

• Real time, remote monitoring of power levels provided via network interface• Power broken down into three categories, each with their own batteries

– Low voltage for microcontrollers, feedback controllers, and sensors• Low voltage supply with low power draw can guarantee long battery life for computer

systems used to operate and control the rest of the pod’s systems– Medium voltage for small actuators

• 12V operating point provides a universal supply for motors, servos, and other small to medium actuators

– High voltage for compressor• Due to the motor’s high current draw a large battery pack must be used so that many

cells operate in parallel. This prevents the individual cells from dropping too far below their rated voltages even at high current

• 100Ah battery pack delivers 17.41kW to the compressor fan motor

62

Preliminary Bill of Materials

Pod Components Custom Built or Commercial Off the Shelf

Passenger Seats Commercial Off the Shelf

Skids Custom BuiltHyperloop Truss Custom Built

Suspensions Skid Custom BuiltAerodynamic Paneling Custom Built

Fire Extinguishers Commercial Off the Shelf

Valves Commercial Off the Shelf

Permanent Magnets Commercial Off the Shelf

Magnet Suspensions Custom BuiltDirectional Wheels Custom Built

Wheel Brake Commercial off the Shelf

Brake Suspension Custom Built

Magnetic Brake Control (Servos) Commercial off the Shelf

Emergency Brake Control Custom Built

Communication Unit Commercial off the Shelf

Micro-controller Commercial off the Shelf

Active Power Management Custom Built

Amplified Photodiode Array Commercial off the Shelf

Temperature Sensors Commercial off the Shelf

System Release Valves Custom BuiltPassengers Custom BuiltSkid Piping Custom Built

Compressor Power System Commercial off the Shelf

Fan Commercial off the Shelf

Aluminum Inlet Custom BuiltFan Tunnel and T Custom Built

Motor Commercial off the Shelf

63

Cost Breakdown

Pod SubsystemPod Components

Unit Count Unit Cost $ (FY 2016) Total Cost $ (FY 2016) Confidence Level Contingency CBE Cost $ (FY 2016)

LevitationSystem

Fan 1 $ 485.00 $ 485.00 7 15.00% $ 557.75

Aluminum Inlet 1 $ 600.00 $ 600.00 6 20.00% $ 720.00

Fan Tunnel and T 1 $ 500.00 $ 500.00 6 20.00% $ 600.00

Skid Piping 1 $ 300.00 $ 300.00 4 30.00% $ 390.00

System Release Valves

6 $ 30.00 $ 180.00 7 15.00% $ 207.00

Valves 4 $ 80.00 $ 320.00 4 30.00% $ 416.00

Skids 4 $ 200.00 $ 800.00 5 25.00% $ 1,000.00

Structure

Hyperloop Truss 1 $ 4,391.50 $ 4,391.50 7 15.00% $ 5,050.23

Suspensions Skid 4 $ 200.00 $ 800.00 5 25.00% $ 1,000.00


1 $ 2,190.00 $ 2,190.00 6 20.00% $ 2,628.00

Magnet Suspensions

2 $ 80.00 $ 160.00 5 25.00% $ 200.00

Wheel Suspension 2 $ 200.00 $ 400.00 6 20.00% $ 480.00

ElectricalPower System

Motor 1 $ 2,780.00 $ 2,780.00 7 15.00% $ 3,197.00

Permanent Magnets

6 $ 150.00 $ 900.00 6 20.00% $ 1,080.00

Compressor Power System

1 $ 4,876.00 $ 4,876.00 7 15.00% $ 5,607.40

Magnetic Brake Control (Servos)

2 $ 60.00 $ 120.00 7 15.00% $ 138.00

64

Cost Breakdown

Navigation

Wheel Control 2 $ 150.00 $ 300.00 6 20.00% $ 360.00

Communication Unit (Space X)

1 $ - $ - 7 15.00% $ -

Micro-controller 1 $ 50.00 $ 50.00 7 15.00% $ 57.50

Amplified Photodiode Array

2 $ 5.00 $ 10.00 7 15.00% $ 11.50

Temperature Sensors

2 $ 50.00 $ 100.00 7 15.00% $ 115.00

Stability &Controls

Wheel Brake 4 $ 40.00 $ 160.00 6 20.00% $ 192.00

Wheel Suspension 2 $ 200.00 $ 400.00 6 20.00% $ 480.00

Directional Wheels 4 $ 140.00 $ 560.00 7 15.00% $ 644.00

Payloads

Passengers 2 $ 500.00 $ 1,000.00 7 15.00% $ 1,150.00

Passenger Seats 2 $ 250.00 $ 500.00 7 15.00% $ 575.00

Fire Extinguishers 2 $ 50.00 $ 100.00 7 15.00% $ 115.00

MEV Total $ 23,210.50 $ 27,213.58

65

Pod Performance Analysis: Aerodynamic Flow Visualization

Oil path lines show the significant flow changes on the aerobody above both of the air bearings, as well as the reverse flow and flow separation on the tail of the fairing

66

Loading and Unloading Logistics Plan

Pod Loading Sequence

• Before loading, the Team Captain will give a 15-minute Safety and Logistics briefing to the Judging Panel and Hyperloop Test Director (a SpaceX or Tesla employee).The Hyperloop Test Director will also lead a safety and technical inspection of the physical Pod. The loading cannot proceed until the Hyperloop Test Director approves.

• Pod will be transported via road to the Hyperloop Staging Area. Pods will be lifted, via a SpaceX-provided crane if necessary, onto the Staging Area, an open-air flat surface 20 feet in length.

• On the Staging Area platform, the Pod will perform Functional Test A, which will include a demonstration of power-up.

• When Functional Test A is complete, Gate 1 will open and the Pod will be moved into the Hyperloop using the Pod’s External Transport System.

67

Loading and Unloading Logistics Plan(Cont.)

Pod Loading Sequence (Cont.)

• In the Hyperloop, the Pod will be physically connected to the Mechanical Propulsion Interface.

• Gate 1 will then be closed and Functional Test B will be performed.

• The Hyperloop will be depressurized to operating pressure.

• At operating pressure, Functional Test C will be performed while operating on the Pod’s internal power.

68


Pre - Launch Functional Tests

• Test A: The Pod shall be powered on and the two-way communication link shall be established.

• Test B: The Pod’s communication link shall be reestablished. It shall be verified that the pod is sending out a full readout of data from the sensors. In addition, it shall be verified that the Pod is responding to commands

• Test C: The Pod’s levitation system shall be activated and hover at a height of .05 inches.

69


Pod Unloading Sequence:

• Once the is pod within 50 feet of Gate 2, the Hyperloop shall be pressurized.

• The Pod shall send a report when the Hyperloop is safe to enter and when the Pod is safe to approach.

• Gate 2 shall be opened once the Test Director deems the operation safe.

• The Pod shall be moved to the Exit Area on the External Transport System and powered down to the Ready-To-Remove state.

• The Pod shall be removed with the crane.

70

Description of Safety Features

Mitigation of Complete Loss of Power:• Each major subsystem shall have a dedicated battery

– Air Intake System– Levitation System– Braking System– Microcontrollers and Sensors

• In the case of a power loss from one battery, most systems shall have contingencies in place to ensure that the pod either reaches the exit point, or it comes to a safe stop. (Air Mass Intake System power loss shall be addressed later

– In case of a sensor and microcontroller failure, the eddy current brakes shall be engaged and the Pod shall be brought to a complete stop.

– The power-off state of the linear magnetic brakes is engaged, meaning that the brakes are aligned with the rail to brake the pod. In the event of a power failure, the clamping brakes will be engaged and left in that state until stored energy expires completely.

– In the event of a loss of power to the levitation system, the Pod shall continue to the exit point. The power-off state of the valves is fully open, so stored energy is released. Additionally, there are safety valves for the pressure system that default to open unless supplied with power. If the height of the Pod decreases even with these precautions, the brakes shall be engaged and the Pod brought to a full stop.

71

Description of Safety Features(Cont.)

Recovery Plan• The Hyperloop shall pressurize. This shall be confirmed by the Pod if the network

connection is still operational.• The Pod’s External Transport shall enter the Hyperloop and approach the Pod.• The Pod shall be loaded onto the transport, and wheeled to the Exit Area. • The SpaceX provided crane shall lift the Pod and Transport System out of the

Hyperloop area.Implementation of the Pod-Stop command

• Upon receiving the Pod-Stop command, the Pod shall initiate a full stop. The linear eddy current brake shall engage and slow the Pod down to a speed of 20 mph.

• The linear eddy current brake shall then disengage and the mechanical brake shall use the middle beam to slow the Pod down to 0 mph.

• At this point, the air mass intake shall decrease, and the Pod will lower to the ground. The Air Mass Intake System shall then fully shut down.

72


Single Points of Failure• Loss of power to Air Mass Intake System

– If the Air Mass Intake System ceases to function, the air bearings will fail– In this scenario, the Pod would strike the aluminum conductor plates on the ground

and damage would most likely occur to the Pod and the Tube– However, the Pod would not strike the side of the Tube due to the mechanical

suspension system which keeps the Pod centered in the Tube

Rapid Tube Pressurization• In the case of rapid re-pressurization, the Pod shall be unable to reach the end

point due to increased drag forces• However, no damage or other adverse effects shall happen to the Pod

– The levitation system is capable of operating at atmospheric conditions

73


Fault tolerance of braking, levitation, and other subsystems• We have emergency brakes as well as redundant brakes that operate in the

unlikely event that the low-speed or high-speed brakes fail• In the event of a failure to the air bearings, a feedback control shall cease air-flow

to air bearings and activate brake

74

Description of Safety Features: Failure Mode Effect Analysis

Subsystem Function Potential Failure Mode

Potential Effects of Failure

Severity Rating

Potential Cause(s) of Failure

Occurance Rating Current Process Control

Levitation System Provide Air CushionFails to provide

necessary airflow for lift necessary

Will prevent pod from floating on air cushion 6 Compressor system or

motor failure 2Control systems for the motor and compressor ensure proper

amounts of airflow to each of the air bearings. Control systems will be adequately tested prior to flight

Fails to provide each air bearing with correct

amount of air

Pod will begin to lean on a specific corner 8

Controller failure or not enough air flow through

compressor2

If the air is reduced at a particular air bearing, the pod will begin to lean in that direction, possibly scraping the aluminum track. Valve controls and controller subsystems will be adequately

tested.

Structural FrameProvide a structural

support and distribute loads

May deform due to several structural

design case

The structure could deform or crumple and thus stop distributing the loads correctly

8 If the pod were to crash into a solid structure 1

Structural frame has had several structural loading design cases analyzed using computerized methods. This analysis showed

that the structure is well designed to withstand these loads

May deform due to vibrations

The structure could deform or crumple and thus stop distributing the loads correctly

7

If the motor or compressor vibrates at

a very high specific frequency, it may cause

deformations in the structure

1

Structural frame has had several vibrational modes analyzed using computerized methods. This analysis showed that the structure is well designed to withstand these vibrations with

minimal deformations

Compressor

Provide air intake to supply mass flow to the

air bearing levitation system

Failure to power on Pod will fail to levitate 6 Motor not providing enough power 2 The motor and compressor system will be tested in conjunction

with the levitation system to ensure proper operation

Failure to provide enough air intake

Pod will fail to levitate properly 8 Motor not providing

enough power 4 The motor and compressor system will be tested in conjunction with the levitation system to ensure proper operation

Motor Provide power to run the fan

Failure to provide enough power

Will prevent pod from floating on air cushion

Battery system malfunction 4 The motor and compressor system will be tested in conjunction


Failure to power on Will prevent pod from floating on air cushion 6 Battery system failure 2 The motor and compressor system will be tested in conjunction


Control SystemsProvide commands to

each controllable subsystem

Failure to power onThe pod will be unable to use the subsystems

that require controll6

Battery system failure or poor device build

quality2 Functional tests to ensue that this subsystem behaves properly

Failure to provide correct commands to

subsystems

The pod will be unable to use the subsystem that is not able to be

controlled

8Battery system failure or poor device build


Navigation System Provide measurements and telemetry data Failure to provide data

Will not meet requirement of

continuous data stream5



Failure to provide provide correct data

Will not meet requirement of

continuous data stream5



Power SystemProvide necessary

power requirements to subsystems

Failure to provide necessary power to

subsystems

Will prevent pod from floating on air cushion 7



75

Component and System Testing Plan

• Subsystem Testing– Levitation system– Scale model testing for structural loading– Fan functional test– Stability and control systems– Power systems

• Subsystem Integration and Testing– Power system and fan system– Levitation system and fan system– Levitation and control systems

• System Integration and Test– Assembly of full pod– Full functional system test

GT Hyperloop Pod Final Design Briefing Presentation

Engineering

Transcript of GT Hyperloop Pod Final Design Briefing Presentation