avionics final slides - purdue university college of …...final margin 39.20 db 3 db 39.2 db...

Project BellerophonApril 17, 2008

Avionics

AAE 450 Spring 2008

Avionics

OverviewAvionics

Telecommunications

Vehicle Ground

Flight Control

Data Processing

Inputs Outputs

Power Systems

Source

Antennas

Data Channels

Tracking

Antennas

Data Channels

Data Processing

Sensors Controls Supply

Avionics

AAE 450 Spring 20081

Electronic Parts: Component Rating

Commercial Class B Class S

Commercial Requirements Class S Requirements

Infinite production lot size Built one at a time

No burn-in testing Extended burn-in time (up to 240 hours)

No detailed failure analysis Extended failure analysis

No life testing 1,000 hour life test on every lot

No traceability Traceable to the raw materials

> 1% failure per 1000 hours allowed 0.0001% failures per 1000 hours allowed

1 NASA Electronics Parts Assurance Group

Avionics


Telecom Analysis: Doppler ShiftFrequency Shift due to Doppler Effect

120

140

160

180

200F

requency S

hift

(kH

z)

401 MHz

1.45 GHz

2.2 GHz

3.0 GHz

0 2000 4000 6000 8000 10000 12000 14000 16000 180000

20

40

60

80

100

120

Vehicle Velocity (m/s)

Fre

quency S

hift

(kH

z)

Avionics


Telecom Analysis: Data Rate

15

20

25

Lin

k M

arg

in (

dB

)

401 MHz

1.45 GHz

2.2 GHz

3.0 GHz

3 dB Margin

Change in Link Margin due to Data Rate

0 1 2 3 4 5 6 7 8 9

x 107

0

5

10

15

Data Rate (bps)

Lin

k M

arg

in (

dB

)

Avionics


Telecom Analysis: Path Length

15

20

25Lin

k M

arg

in (

dB

)

401 MHz

1.45 GHz

2.2 GHz

3.0 GHz

3 dB Margin

Change in Link Margin due to Signal Path Length

0 1000 2000 3000 4000 5000 6000 7000 80000

5

10

15

Path Length (km)

Lin

k M

arg

in (

dB

)

Avionics


Telecom Design: Vehicle Link Budget

Item Value Units

frequency 401 MHz

transmitter power 5 Watts

transmit antenna beamwidth 60 deg

transmit antenna diameter 0.87 m

equiv isotropic radiated power 12.3 dB-W

Simplified Link Budget

Minimum Margin: Vehicle Margin:equiv isotropic radiated power 12.3 dB-W

propagation path length 5,000 km

receive antenna diameter 10 m

receive antenna beamwidth 5.24 deg

data rate 9,600 bps

signal to noise ratio 50.82 dB

carrier to noise density ratio 90.64 dB-Hz

bit error rate 0.00001 ---

implementation loss -2 dB

final margin 39.20 dB

3 dB 39.2 dB

Avionics


� Range Safety Officer (RSO)– An individual who is responsible for the remote destruction and

consequent flight termination of the launch vehicle should it be deemed a hazard.

� RSO Responsibilities

Range Safety: Personnel

� RSO Responsibilities– Evaluate the launch vehicle design as well as oversee the manufacturing

process.

– Monitors the launch vehicle and environmental conditions prior to launch.

– Monitors and tracks the launch vehicle during flight.

� Hiring– Budget $1,700 per launch, assuming a 5 day period.

Avionics


� Flight Corridor– An imaginary zone that exists in a space above the launch range.

� Application– Implemented so that if the launch vehicle where to experience a failure

Range Safety: Flight Corridor

– Implemented so that if the launch vehicle where to experience a failure during flight, the vehicle will fall to the ground in an uninhabited area.

� Termination– The launch vehicle must be destroyed if it flies outside the predetermined

flight corridor.

Avionics


Non-Space-Rated Sensors

Sensor Type Part Number Manufacturer Unit Price

Thermal TS3-85 Cantherm $10.29

Pressure 2000260Measurement

Specialties Inc.$104.06

Specialties Inc.

Flow 26616 Gems Sensors, Inc. $154.95

Force FSS1500NSRHoneywell Sensing

and Control$46.56

Avionics


Space-Rated Sensors

Sensor Type Part Number Manufacturer

Unit

Price

Thermal S311-641/04

Honeywell

Sensing and

Control

$800

Control

Pressure PPTR

Honeywell

Sensing and

Control

$970

Avionics


Sensor Reliability Analysis: Thermal

Sensor Company Accuracy Reliability

270 Space Series Honeywell Aerospace

±2.8°C 100,000 Cycles

MCP9700/9700A (non-space-rated)

Microchip ±2°C none

AS-TE (space-rated)

Fluid Components International

± 0.3° C 200,000+ Hours

Various (space-rated)

Measurement Specialties

±0.01˚C 3500 cycles(can be specified)

This table details the reasons for differences in cost.

Avionics


Power Supply: Power BudgetVehicle Flight Time Balloon Rise Time

Vehicle System

Percent of Operating

PowerPower

(W)

Energy Consumption

(Wh)Mass

(kg)Power

(W)

Energy Consumption

(Wh)Mass

(kg)Payload 5 10 1.04 0.01 10 30.00 0.27Propulsion 35 70 7.25 0.07 0 0.00 0.00Attitude Control 15 30 3.11 0.03 0 0.00 0.00Attitude Control 15 30 3.11 0.03 0 0.00 0.00Communications 10 20 2.07 0.02 20 60.00 0.55Command and Data Handling

5 10 1.04 0.01 10 30.00 0.27

Thermal 5 10 1.04 0.01 0 0.00 0.00Power Management

25 50 5.18 0.05 10 30.00 0.27

Total 100 200 20.72 0.19 50 150.00 1.361.5 Safety Factor 300 31.08 0.28 75 225 2.05

200g Payload Case, Silver Zinc Battery, Balloon Launch

Avionics


Power Supply: Battery Selection

LiCF Li SOCl2 AgZn

Watt-Hours/Kilogram 130 185 110

Watt-Hours/Liter 160 240 200

Discharge Rate Low Moderate HighDischarge Rate Low Moderate High

Failure Tolerance Low Low High

Cell Voltage 2.95V 3.1V 1.5V

Experience Level High Moderate High

Costs Low Low Low

Avionics


Power Supply: AgZn Battery

AgZn Benefits

� Can charge 4 to 6 times in case of scrub

� Capable of controlling

Silver Zinc (AgZn)Battery Property Value

Weight (kg) 2.3 - 4.5

Volts (V) 1.6 - 1.85

� Capable of controlling gimballing, ignition, and range safety subsystems

Rated Capacity (Ah) .8 - 800

Specific Energy (Whr/kg) 55 - 286

Energy density (Whr/l) 55 - 262

1http://www.eaglepicher.com/

Avionics


Power Supply: Batteries

Battery Weight Wh/kg Cost

Silver-Zinc (AgZn) 2.3-4.5 kg 110 ~$10,000

Lithium-Monofluoride (Li/CF)

2.3-4.5 kg 130 --------

Estimate Cost: < $10,000 Weight: 2.3-4.5 kg

Monofluoride (Li/CF)

Lithium/ThionylChloride (Li/SoCl2)

2.3-4.5 kg 185 --------

Avionics


Installation Cost

Primary Contractor: Aircraft Electrician

Median Salary1 $40,984.00

Work Days per Year 240Income Per Day $170.77Income Per Hour $21.35Income Per Hour $21.35Billing Rate Per Hour $32.02

At four weeks of billable workInstallation Cost: $7,172.20

1 Salary data from www.salary.com

Avionics


Telecom: Failure Analysis

Sources

TelecomEquipment

Radio

• Transmitter• Receiver

ExternalSources

Doppler Shift

Reliability Factors

For a low complexity system with redundancy1:

Part Class ReliabilityClass B: 98.75%Sources

ofFailure

• Receiver• Antenna

Data Handling

• Data processing

• Data wiring

Power Supply

Orientation Misalignment

Class B: 98.75%Class S: 99.87%

Assumptions- Simple system- Low radiation dose- Reliability based on a five year mission plan

1 Wertz, 404.

Avionics


� First Stage: 6.024 kg total (safety factor=1.2)-wiring: 2kg

-sensors 1.02kg

-battery 2kg

� Second Stage: 30.2664 kg total (safety factor=1.2)

Mass Budget

-Telecom: 10 kg -CPU: 0.85 kg

-Sensors: 1.02 kg -Range Safety: 9.23 kg

-Wiring: 2 kg -IMU: 0.122 kg

-Battery: 2kg

� Third Stage: 1.2 kg total (safety factor=1.2)-Wiring: 1 kg

Avionics


� Launch lock (US Patent 6508437)

� Motorized release

� Explosive Bolt/Spring sequence1

Payload: Launching Options

� Explosive Bolt/Spring sequence

� Explosive/Slingshot Sequence

1(Professor Filmer), (International Reference Guide to Space Launch Systems pg 296)

Avionics


� Assumptions Made– The Earth is spherical in shape.

– The area where the signal intercepts the Earth is circular.

– Neglect any antenna mounting errors or design issues.

– Neglect any atmospheric anomalies which may refract the signal.

Signal Projection: Assumptions

– Neglect any atmospheric anomalies which may refract the signal.

– The signal propagation from a cluster of directional antennas can be estimated using a omnidirectional antenna.

– The signal propagation from an omnidirectional antenna is spherical in shape.

Avionics


Approximate Ground Equipment Costs1

Radio ($1,200)

Antennas ($500)

Example Case: Small Payload Launch Vehicle

Launch Vehicle Tracking

1Professor Filmer, Purdue University School of Aeronautics and Astronautics

Antennas ($500)

Computer ($2,000)

Misc ($500)

Total: $4,200

LV Ground Track Balloon Ground Track

236.09 km 120.74 km

Mean Propagation Radius

4,995.4 km

Avionics


Avionics: Cost Budget

Unit Costs

Wiring - Materials $ 500

- Installation $ 7,500

CPU $ 10,000

IMU $ 15,000IMU $ 15,000

Sensors (500 each) $ 8,000

Battery $ 10,000

Range Safety $ 20,000

Ground Tracking $ 24,000

Total $ 95,000

Avionics


avionics final slides - purdue university college of …...final margin 39.20 db 3 db 39.2 db...

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