1 May 18, 2007Team # 7103: METEOR Instrumentation Platform M.E.T.E.O.R. Instrumentation Platform...

May 18, 2007 Team # 7103: METEOR Instrumentation Platform 1

M.E.T.E.O.R.M.E.T.E.O.R.Instrumentation PlatformInstrumentation Platform

2006-2007

Matt LipschutzRashmi Shah

Adam GuttermanJessica DeSignor

Rick FrisicanoPeter Rozwood

Sponsor:


OverviewOverview

• MMicrosystems• EEngineering and

• TTechnology for the

• EExploration of

• OOuter Space

• RRegions

Balloon

Platform

Rocket

Picosat

Track Objective: Develop a low-cost balloon-assisted in-air rocket launch system capable of placing small (~1kg) satellite payloads into a low-earth orbit (LEO).


Instrumentation PlatformInstrumentation Platform

• Project Objective:– Further develop an independent balloon-lofted computational

platform capable of monitoring the environment and communicating in near real time with ground control stations

• Key Customer Needs:– Transition component infrastructure to MSP430 microprocessor– Design and implement RF power amplifier for video transmission– Design and implement custom portable microcontroller-based

OSD– Develop modular transient thermal model– Analyze and redesign legacy components such as radios and

sensors


System Block DiagramSystem Block DiagramBatteries

Power Distribution

Main Processor

Sensor DataGPS

TinyTrak

2mRadio

Cameras

Video Multiplexer/Text Overlay

70cmTransmitter

Modem

Antenna


PackagingPackaging

• Created geometric models of main components, circuit boards, and assemblies.

• Arranged items to fit inside 8”x8”x3.5” envelope for future fit into the Glider (METEOR 07108)


Exploded ModelExploded Model


Thermal AnalysisThermal Analysis

• Created transient thermal model of the instrumentation platform during flight using ANSYS Workbench software

• Set up important properties as parameters that can be easily modified to investigate multiple scenarios

• Set variable and steady-state properties to initial default values selected though research


Thermal Simulation ResultsThermal Simulation Results

• With the initial set of parameters, the results predict that the electronics do not dissipate enough heat to keep the platforms internal temperature in a safe operating range. The internal temperature drops below -40°C at approximately 52,000ft.


Controller and SensorsController and Sensors

• MSP430: Primary functions:– Process ground control commands– Data collection:

• GPS: position, altitude, speed, heading• Sensors: temperature, pressure, humidity and accelerometer

– Generate data packets for the following:• Transmission to ground based receivers• Video text overlay

• Future Improvements– Develop a standard data package for radio

transmission to ground control– On board data storage


Controller FlowchartsController Flowcharts


• Inputs: NTSC Video signal (1vp-p, 3.5MHz baseband), 8-bit custom serial communication (max frequency 1MHz)

• Output: NTSC Video signal with data from serial displayed on bottom of screen

On-Screen-Display (OSD)On-Screen-Display (OSD)


W 2 R I T M E T E O R 4

Collate to binaryvalue

0000000

1111110

1000000

1000000

1111100

1000000

1000000

1111110

0000000

Calculate decimalvalue

0

126

64

64

124

64

64

126

0

Character GenerationCharacter Generation

0 0 0 0 0 0 0 0

0 1 1 1 1 1 1 0

0 1 0 0 0 0 0 0

0 1 0 0 0 0 0 0

0 1 1 1 1 1 0 0

0 1 0 0 0 0 0 0

0 1 0 0 0 0 0 0

0 1 1 1 1 1 1 0

0 0 0 0 0 0 0 0


OSD Program FlowchartsOSD Program Flowcharts

Infinite wait loop

Port 1 Interrupt Service Routine

Hsync detected?

Vsync detected?

Communication Requested?

Clear Interrupt

flag

Increment line counter

Call Draw()

Reset line counter to

zero

Disable Port 1

Interrupts

Call Receive()

Set Failsafe Timer

Timer Interrupt Service Routine

Disable Timer

Clear Timer

interrupt flag

Enable Port 1

interrupts

Intiailize

Yes

No

Yes

No

Yes

No

Receive()

Is Data pin low?

Write character to RAM

Draw()

Is line between 220 and 230?

Return to Interrupt Service

Routine

Calculate Character pointer [LT] to

determine bitstream output per line

Output bitstream of character n from

receive string

Loop for 21 characters

Loop for 8 bits

Clear temp

Wait for Clock pin High

Bit Shift Temp right by one

Write one to Temp

Wait for Clock pin Low

End 8 bit loop

End 21 character loop

No

Yes

No

Write zero to Temp

Yes


Video Transmitter FlowchartVideo Transmitter Flowchart• The purpose of the transmitter is to

transmit the video signal from the Instrumentation Platform to ground

• MAX2370 450MHz Quadrature Transmitter

• Internal registers allow for IF frequency tuning to 120MHz – 125MHz

• Upconverts to a RF frequency of 439.25MHz on the 70cm band

• Includes a tuning voltage VGC from 0.5V to 2.5V to provide an output power of 8dBm – 30dBm

• RA07H4047M power amplifier module takes an input power of 20dBm and outputs at least 7W of power

OSD

Microprocessor

Transmitter Power

Power Amplifier

SH

DN

IDLE

TX

GA

TE

Video In +3.3V, +5V

Vid

eo O

ut

+12V

Video Out


MAX2370 Evaluation KitMAX2370 Evaluation Kit

• Design taken from MAX2370 EV Kit (left) and customized to fit our needs


Video Transmitter PCB LayoutVideo Transmitter PCB Layout

• 4 Layer Board– Top layer (top left)

– Bottom layer (top right)

– Inner power layer +3V

– Inner ground layer

• 50 ohm traces for matching


Radio Data LinkRadio Data Link

• Facilitates communication between platform and ground– Downlink: Sent position reports and sensor

data• Can be received directly with specialized receivers• Data posted automatically to Internet using existing

infrastructure: required only a URL to access

– Uplink: Received commands from ground station and sends them to central processor


Radio Data Link:Radio Data Link: Block Diagram & Notable Features Block Diagram & Notable Features

• Range: 100+ miles• Redundancy

– Extra GPS and circuitry: Position reports are still sent even if central microprocessor fails

– Low-power non-directional beacon for short-range tracking (range ~0.4 mi)


Data Radio ResultsData Radio Results

• Designed redundancy setup was insufficient and failed in flight

• Transmitter system did not report position data reliably; final position unknown

• Extensive search failed to locate IP using only non-directional beacon frequency

• Future work: move backup position reporting system to completely independent power source to aid recovery in case of similar failure


Power System DesignPower System Design

• Improved Efficiency:– Linear: 3.3V at 20% efficiency to 80% efficiency using new

switcher (from 18V)– Linear: 12V at 75% efficiency to 95% efficiency using new

switcher (from 18V)

• Surface mount parts (latest switching power supplies)

• New voltage rails (+/-12, +5, +3.3) all use switching voltage regulators

• Low cost: $50.43 out of a $10,000 group budget• Have the ability to supply all components including the

3A requirement on the +12 V rail


Power System SchematicPower System Schematic


Power System PCB LayoutPower System PCB Layout


Power System PerformancePower System Performance

• 3.3, 5, and +12 V rails were within 1/100 volts of accuracy. –12 was within .5 V of accuracy

• Improvements: – adding a power switch – Replacing –12 V regulator with one that can run off of

+18 V instead of +12 and can power exactly –12 V instead of –11.5 V

– Adding a set of holes on all four sides of the board for attachment onto the platform frame.

• Other than those improvements, the power system ran as expected.


QUESTIONS ?QUESTIONS ?

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1 May 18, 2007Team # 7103: METEOR Instrumentation Platform M.E.T.E.O.R. Instrumentation Platform...

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