Avionics, Software, and Simulation

Avionics, Software, and Simulation

Doug AstlerAlex KrajewskiChris O’Hare

Dennis Sanchez

Crew Capsule Selection

• Team C4’s crew capsule was selected because it has no external elements, which leaves room for sensors

• It also has the highest mass margin, we therefore have the most available sensor mass total to work with

Link Budget Communications link budgets were created for the following links. A safety factor of 2 (3 dB) is used for determining transmitter size and power.

Band Transmitter Receiver Distance range (km)

Use Scenario

Ku Spacecraft Earth station

2k – 384k LEO, Transit, Lunar orbit

Ku Spacecraft Relay sat 384k Transit relay

Ku Relay sat Earth station

448k Transmission relay

Ka Spacecraft L2 Relay sat

64k Lunar orbit/landing - dark side

S Spacecraft Earth Station

2k – 384k LEO, Transit, Lunar orbit

UHF Spacecraft EVA suits < 10 Space, lunar EVA

Link Budget - ReceiversThe spacecraft will make use of different receivers during the mission;• Deep Space Network

• Provides continuous possible coverage from three stations• Large dishes can pick up weak signals• Has some no-coverage spots within 30,000 km altitudes

• TDRSS• TDRSS can relay transmissions to grounds stations• Useful if DSN is not available• No atmospheric concerns for signal

• L2 Relay satellite• A theoretical satellite in the L2 Lagrangian point will help maintain

continuous communication during orbital and lunar surface times on the dark side of the moon

• This will be modeled as a TDRSS satellite• EVA suits

• Communication must be maintained with crew during all EVA missions

Link Budget - Receivers

Dish size (m) Max Distance (km)

Bands supported

DSN 34 384k Ku, S

TDRSS 4.9 384k Ku

L2 Relay (TDRSS)

4.9 65k Ka

EVA N/A 10 UHF

This table represents the relevant statistics of the various receivers used in this mission.

Link budget - Diagrams

(1) Spacecraft to DSN(2) Spacecraft to TDRSS(3) Spacecraft to L2 relay satellite(4) L2 Relay sat to DSN/TDRSS

Link Budget - Spacecraft• To minimize transmitter mass and size, one transmitter dish will

be used for all three bands considered• This will limit communications to only one link at a time

• Size and power requirements will be dictated by the band with the greatest requirements (in bold)

Spacecraft To DSN To TDRSS To L2

Ku S Ku S Ka

Transmitter Antenna Diam (m)

0.10 0.10 0.1 0.25 0.10

Transmitter Power (W)

0.09 7.55 4.15 15.5 0.05

Link Margin (dB)

3.23 3.02 3.05 3.1 3.03

Link Budget – Relay Sat• The L2 relay sat antenna size is being modeled on

TDRSS• We assume that it must reach earth from the L2

Lagrangian position

L2 Satellite To DSN To TDRSS

Ku KuTransmitter Antenna Diam (m)

4.9 4.9

Transmitter Power (W) 0.001 0.04Link Margin (dB) 12.72 3.07

Link Budget - UHF Omni

• UHF omni antenna will be used for both space and lunar EVA

• Maximum EVA distance is 10 km (Apollo legacy)

Spacecraft To EVA Suits

UHF Omni

Transmitter Power (W) 0.001

Link Margin (dB) 4.39

Link Budget – Final Stats

Antenna Ka, Ku, S band UHF OmniDiameter (m) 0.25 N/A

Max Power (W) 15.5 0.001

Link Margin (dB) 3.1 4.39

These are the final stats, that will drive the size and maximum power draw of the transmitters.

Different Bands of FrequencyMicrowave Frequency Band

Band Frequency Range

L band 1 to 2 GHz

S band 2 to 4 GHz

C band 4 to 8 GHz

X band 8 to 12 GHz

Ku band 12 to 18 GHz

K band 18 to 26.5 GHz

Ka band 26.5 to 40 GHz

Q band 30 to 50 GHz

U band 40 to 60 GHz

V band 50 to 75 GHz

E band 60 to 90 GHz

W band 75 to 110 GHz

F band 90 to 140 GHz

D band 110 to 170 GHz

TransmitterDue to the small transmitter being used, signal beams will be narrow. This necessitates accurate transmitter pointing.

Ka Ku S

λ (m) 0.009375 0.025 0.12

θ (deg) 2.14 5.72 27.5

θ=λ /𝐷

TransmitterTransmitter will be mounted on a 2 DOF rotational mount• Provides 2π steradian coverageSpacecraft will contain 2 transmitters at opposite sides• Minimizes spacecraft attitude maneuvers to send a

transmission• Provides redundancy in the event of a transmitter failure

Different Bands of FrequencyEU, NATO, US ECM frequency designations

Band Frequency RangeA band 0 to 0.25 GHzB band 0.25 to 0.5 GHzC band 0.5 to 1.0 GHZD band 1 to 2 GHzE band 2 to 3 GHzF band 3 to 4 GHzG band 4 to 6 GHzH band 6 to 8 GHzI band 8 to 10 GHzJ band 10 to 20 GHzK band 20 to 40 GHzL band 40 to 60 GHzM band 60 to 100 GHz

Information Needed Type of Sensor(s) Needed Example

Attitude dynamics Rotary position sensor, position sensor, and acceleration sensor

Star Tracker

Pressure in the cabin Pressure sensor MPL115A

Temperature in the cabin Temperature Sensor DS18B20

Oxygen and Carbon Dioxide levels in the cabin

Oxygen sensor and Carbon Dioxide sensor

TR250Z and Dynament

Radiation levels in the cabin Radiation Sensor Geiger Counter

Docking and landing Proximity Sensors E2EM

System deployment (landing gear)

Electric Power monitoring equipment, Proximity sensor

KM50-E and E2EM

System and Electronic functioning

Electric Power monitoring equipment

KM50-E

Propulsion tank leakage Liquid Leakage Sensor K7L-AT50/ -AT50D

Sensors

DS18B20 Programmable Resolution 1-Wire Digital Thermometer


• Provides 9-bit and 12-bit Celcius temperature measurements

• Accuracy of ± 0.5°C in range of -10°C to 85°C• Accuracy of ± 2°C in range of -55°C to 125°C• Operating temperature range

• -55° to 125°C• Power Supply

• 3.0 – 5.5 Volts DC• Current Consumption

• 1 to 1.5mA DC


• Sampling Rate• Temperature conversion times

– 9 bit resolution = 93.75ms– 10 bit resolution = 187.5ms– 11 bit resolution = 375ms– 12 bit resolution = 750ms

• Signal Band• Max can be is 1.3 GHz for signal output

• Criticality• Used to check internal temperature of crew system vehicle to

make sure it is around room temperature for crew• Ensures astronauts are safe

MPL115A Digital barometric pressure sensor


• Measures an absolute pressure range of• 0 – 115 kpa

• Accuracy of ± 1kpa in range of -20°C to 85°C• Operating temperature range

• -40°C to 105°C

• Power Supply• 2.4 – 5.5 Volts

• Current Consumption• Sleep Mode = 1μA• Active = 5μA at one measurement per second


• Sampling Rate• 1 measurement per second

• Signal Band• Max can be is 8 MHz for SPI timing component

• Criticality• Used to check internal pressure of crew system

vehicle to make sure it is safe for crew• Ensures astronauts’ safety during the mission

TR250Z Oxygen Sensor

TR250Z Oxygen Sensor• Measures O2 in a range of 0 to 25% or 0.1

to 95%• Accuracy of ± 0.5% (2% full scale)• Operating temperature range

• -10°C to 70°C• Power Supply

• 24 V DC ± 10%• Current Consumption

• 600 mA @ 24V DC

TR250Z Oxygen Sensor

• Sampling Rate• Sampling is done by diffusion with (ZrO2)

Zirconium dioxide• 4 sec max diffusion time

• Signal Band• 13.8 GHz to 14.7 GHz

• Criticality• Used to check internal levels of oxygen of crew

system vehicle to make sure the crew can breath

DYNAMENT CARBON DIOXIDE INFRARED SENSOR


• Measures CO2 in a range of 0 to 1000ppm up to 0 to 5% volume CO2

• Accuracy of ± 1% measuring range• Operating temperature range

• -20°C to 50°C• Power Supply

• 3V to 5V DC• Current Consumption

• 60 mA• Response time of <30 sec in 20°C


• Sampling Rate– Response time <30 sec in 20°C temperature

• Signal Band• Source drive frequency:

– 2Hz minimum– 3Hz typical– 4Hz maximum

• Output signal is around 15 MHz

• Criticality• Used to check internal levels of carbon dioxide of crew

system vehicle to make sure the crew does not suffer carbon dioxide poisoning

MLX90316 Rotary Position Sensor IC

MLX90316 Rotary Position Sensor IC• Absolute rotary position IC with Magnetic design• Measures from 0 to 360 degrees• Voltage Requirement

• 4.5-5.5 V• Has a 10V voltage protection

• Current Consumption• Slow mode = 8.5-11 mA• Fast mode = 13.5-16 mA

• Temperature Range• -40°C to 150°C

MLX90316 Rotary Position Sensor IC

• Sampling Rate• Slow mode = 600 μs• Fast mode = 200 μs

• Signal Band• Slow mode = 7 MHz• Fast mode = 20 MHZ

• Criticality• Used to measure the rotational position of the

spacecraft during attitude dynamics

Bosch Sensortec BMA180 Digital triaxial acceleration sensor


• Three axis accelerometer with integrated temperature sensor

• ultra-low noise and ultra high accuracy• Programmable g-ranges (1g, 1.5g, 2g, 3g, 4g, 8g, 16g)• Zero-g Offset

• ±5 to 60 mg• Voltage Requirement

• 4.25 V

Current Consumption• For sleep mode to low noise mode 0.5-975 μA



• Bandwidth• High pass = 1Hz• Band pass = 0.2 – 300 Hz

• Sampling Rate• 1200 samples/sec

• Signal Band• Noise density @1200Hz, 2g, 150-200 μg/√Hz• Input runs on 7.5-10 MHZ• Outputs data at 2400-1200 Hz

• Criticality• Used to measure the acceleration and the spacecraft’s

respective position

Bosch LRR3: 3rd generation Long-Range Radar Sensor


• Detect objects and measure velocity and position relative to movement of host radar-equipped vehicle

• Distance accuracy 0.5…250m (±0.1m)• Relative speed accuracy -75…+60m/s (±0.12m/s)• Vision Range

• Horizontal opening angle 30° (-6 dB)• Vertical opening angle 5° (-6dB)

• Power Consumption• Typically 4 W

• Temperature Range• -40°C to 85°C (periphery)

• Max Number of detected Objects = 32


• Sampling Rate• Cycle time is typically 80ms

• Signal Band• Transmits radar waves in 76-77 GHz

• Criticality• This is useful for landing on the moon as to detect

the distance from the surface of the moon to the spacecraft

SENSOPART Visor Vision Sensor


• Allows sight via flashing light at fast times• Uses 8 LEDS for fast measurement• Takes 13s to power up when turned on• Voltage Requirement

• 24V DC

Current Consumption• About 200 mA



• Sampling Rate• Cycle time is typically 20ms pattern matching• Cycle time is typically 30ms contour• 2ms brightness, contrast, grey level

• Signal Band• Transmits in 62-73 GHz

• Criticality• This is useful for landing on the moon as to detect

craters and dangerous landmasses so the spacecraft can land in the designated location

CT-602 Star Tracker

CT-602 Star Tracker

• Sampling Rate• Cycle time is typically .3 deg/sec

• Signal Band• Transmits radar waves in 10 Hz

• Criticality• The CT-602 features a radiation-hardened

processor and additional memory that combine for increased environmental tolerance and greater mission programmability

E2EM

• Sampling Range• Measures 4 mm distances

• Signal Band• Transmits radar waves in 1 kHz

• Criticality• Long-distance at up to 30 mm enables secure

mounting with reduced problems due to work piece collisions

K7L-AT50 / -AT50DUltra-miniature Sensor Amplifier

K7L-AT50 / -AT50DUltra-miniature Sensor Amplifier

• Rated power supply voltage of 10 to 30 DC• Detection time is 10s max • Current is 100 mA at 30VDC max• Power needed is 1W• Temperature range is -10 to 55°C• Resistance

• Range 0 = 0 to 250 kΩ• Range 1 = 0 to 600 kΩ• Range 2 = 0 to 5 MΩ• Range 3 = 0 to 50 MΩ

K7L-AT50 / -AT50DUltra-miniature Sensor Amplifier• Sampling Range

• 800ms max• Signal Band

• 50/60 Hz for 1 min• Criticality

• Prevents leakage of fuel tanks which would help prevent potential disasters from happening

KM50-EPower Monitor

KM50-EPower Monitor

• Rated power supply voltage of 100 to 240 VAC• Detection time is 10s max • Current is 5,50,100,200,400, or 600 A• Power needed is 4kW to 480 kW• Temperature range is -10 to 55°C• Accuracy for the time is about ±1.5 min/month at 23°C

KM50-EPower Monitor

• Sampling Range• 800ms max

• Signal Band• 50/60 Hz

• Criticality• Tells if any electronics systems are damaged or

broken.

HD25A Magnetic Encoder

HD25A Magnetic Encoder

• Sample Rate • 4 msec

• Signal Band• 20 kHz max

• Critically• Using the HD25A magnetic encoder because it

calculates absolute position and also digital to avoid less errors and noise

Sensors and Signal BandsSensor Frequency Range Band

DS18B20 Programmable Resolution 1-Wire Digital Thermometer 1.3 GHz L band

MPL115A Digital barometric pressure sensor 8 MHz A band

TR250Z Oxygen Sensor13.8 GHz to 14.7

GHzKu

band

DYNAMENT CARBON DIOXIDE INFRARED SENSOR 15 MHZ A band

MLX90316 Rotary Position Sensor IC 7 MHz - 20 MHz A band

Bosch Sensortec BMA180 Digital triaxial acceleration sensor 7.5 MHz - 10 MHz A band

Bosch LRR3: 3rd generation Long-Range Radar Sensor 76 GHz - 77 GHz W band

SENSOPART Visor Vision Sensor 62 - 73 GHz E band

Magnetic Absolute Encoder 20 kHz A band

Sensor Block DiagramPower

KM50-EPower Monitoring

BMA180Triax Accelerometer

DS18B20Temperature

MPL115APressure

TR250ZOxygen

DynamentCO2

MLX90316Rotary Position

LRR3Range

SensopartLanding

CT-602Star

Tracking

E2EMProximity

K7L-AT50Fuel Leakage

HD25AMagnetic Encoder

Computer

InsideOutside Pressure Hull

Power

Data

Sensor Power Requirements

Sensor Used for Voltage RequirementsCurrent Consumption Power Requirement Inside/Outside Craft

DS18B20 Temperature 3-5.5v DC 1-1.5mA .00825 W InsideMPL115A Pressure 2.4-5.5v DC 5μA 2.75E-5 W InsideTR250Z Oxygen 24v DC 600mA 14.4 W InsideDynament CO2 3-5v DC 60 mA .3 W InsideMLX90316 Rotary Position 4.5-5.5v DC 8.5-16 mA .088 W InsideBMA180 Triax Accelerometer 4.25v DC 975 μA .004 W InsideLRR3 Range 4 W OutsideSensopart Landing 24v DC 200 mA 4.8 W OutsideCT-602 Star Tracking 28v DC 9 W OutsideE2EM Proximity Sensor 24v DC 100 mA 2.4 W Outside

K7L-AT50 / -AT50D Fuel Leakage 10-30v DC 100mA .3 W OutsideKM50-E Power Monitoring 7 W InsideHD25A Magnetic Encoder 5.5v DC 16 mA .088 W Outside

Total 42.39 W

Criticality

Crew

Oxygen LevelsTR250Z Oxygen Sensor

CO2 LevelsDynament CO2 Infrared Sensor

Pressure LevelsMPL115A Digital barometric

pressure sensor

Temperature LevelsDS18B20 Programmable Digital

Thermometer

MissionAccelerationVelocityPosition Sensors

This Criticality diagram shows how the crew must come first before the mission because there needs to be a crew to do the mission

Sensor Redundancy

• In order to provide a safe environment for the crew and keep the mission going, we need multiple sensors so if one fails, we have a backup

• We must calculate the probability that at least one sensor will work in case one or more fail in it’s place

Sensor Redundancy

Probability that k out or n units working

Sensor Redundancy• For all the sensors, using the worst mean time

between failures out of all the sensors as a worst case scenario

sec3600*5000sec)3600)*(24)*(13(

hourshoursdays

eR

9395.0R

MTBFt

eR

Sensor Redundancy3 parallel sensors, each has reliability of 0.9395

Probability all three work

%93.82PProbability exactly two work

%02.16PProbability exactly one works

%03.1P

Sensor Redundancy

%93.82PProbability all three work

Probability at least two work

Probability at least one works

Probability that none work

Possible ENAE 484 DBTE Projects

Sight View Mock-Up

• Want to mock-up the capsule view point to assure the astronauts have significant sight lines for landing from the window.

• From mock-up, analyze structure for possible window placement and quantity of windows

• Can shine light through windows in the dark to visualize sight lines easier

Sight View Mock-Up

Inner Configuration Mock-up• Want to design a mock-up of how the inner structure of the crew

systems vehicle is laid out• We will design moveable furniture, such as the chairs, control

panels, cubbies, etc. to see if the space suited crew can operate the controls in a well timed manner

• From this, we will put people in space suits and see if the configuration we designed for the crew systems vehicle is satisfactory– It is satisfactory if the crew can operate all the controls, (within arm’s

length while sitting) and move without much trouble• If it is deemed unsatisfactory, then the furniture and control systems

is moved into a new configuration until a good configuration is found• Goal: To see if the crew can react to situations without much trouble

and to become familiar with the crew systems vehicle before the mission starts

Mock-up: Lunar EgressHatch Design• Objective

• Determine desirable hatch sizes and shapes for egress in spacesuits after cabin decompression

• Analyze ease of exiting/entering through the hatch, ease of opening/closing the hatch

• Analyze performance in zero gravity, lunar gravity• Lunar gravity – further step-down to surface simulation

• Required mockup• Can create a low cost/ low fidelity dry mockup• Can create a higher fidelity neutral buoyancy mockup• Both would require structural construction

• Dry mockup needs more structural support• NB mockup needs more specialized construction

References• Hatcher, Norman M. A Survey Of Attitude Sensors for Spacecraft. Rep. no. NASA SP-

145. Washington, D.C.: Langley Research Center, 1967. Web. 9 Dec. 2012.• MPL115A Digital Barometric Pressure Sensor. Rep. no. MPL115AFS. N.p.: n.p., n.d.

Freescale Semiconductor. Web. 8 Dec. 2012. http://cache.freescale.com/file/sensors/doc/fact_sheet/MPL115AFS.pdf http://cache.freescale.com/files/sensors/doc/data_sheet/MPL115A1.pdf?fpsp=1 http://cache.freescale.com/files/sensors/doc/data_sheet/MPL115A2.pdf?fpsp=1

• DS18B20 Programmable Resolution 1-Wire Digital Thermometer. Rep. San Jose, CA: Maxim Integrated, 2008. Maxim Integrated. Web. 11 Dec. 2012. http://datasheets.maximintegrated.com/en/ds/DS18B20.pdf

• MLX90316 Rotary Position Sensor IC. Rep. no. 3901090316. N.p.: Melexis Micro Electronic Integrated Systems, 2012. Melexis Micro Electronic Integrated Systems. Web. 11 Dec. 2012. http://www.melexis.com/Assets/MLX90316-DataSheet-4834.aspx

• BMA180 Digital, Triaxial Acceleration Sensor. Rep. no. Rev. 2.5. N.p.: Bosch, 2010. Bosch. Web. 10 Dec. 2012.

• http://irtfweb.ifa.hawaii.edu/~tcs3/jumpman/jumppc/1107-BMA180/BMA180-DataSheet-v2.5.pdf

References• Chassis Systems Control LRR3: 3rd Generation Long-Range Radar Sensor. Rep.

N.p.: Bosch, 2009. Bosch. Web. 10 Dec. 2012. http://www.bosch-automotivetechnology.com/media/db_application/downloads/pdf/safety_1/en_4/lrr3_datenblatt_de_2009.pdf

• VISOR- the New Generation of Vision Sensors. Rep. no. 068-14397. N.p.: SensoPart, 2012. SensoPart. Web. 11 Dec. 2012. http://www.sensopart.com/jdownloads/Prospekte/06814397_14_VISOR_e.pdf http://www.sensopart.com/en/products/vision-sensors-a-systems/obect-detection

• HD25A Absolute Industrial Optical Encoder. Rep. N.p.: US Digital, n.d. US Digital. US Digital. Web. 11 Dec. 2012. http://pdf.directindustry.com/pdf/us-digital/hd25a-absolute-industrial-optical-encoder/Show/15092-187916.html

• TR250Z Oxygen Sensor. Rep. no. DSTR250Z. N.p.: CO2Meter, 2012. CO2Meter.com. CO2Meter. Web. 12 Dec. 2012. http://www.co2meters.com/Documentation/Datasheets/DS-TR250Z-sensor.pdf

• Carbon Dioxide Infrared Sensor Temperature Compensated Certified Version Type MSh-CO2/TC. Rep. no. TDS0003. Vol. 4.3. N.p.: Dynament, 2011. Dynament. Web. 11 Dec. 2012. http://www.dynament.com/infrared-sensor-data/tds0003.PDF

Avionics, Software, and Simulation

Documents

Transcript of Avionics, Software, and Simulation