brumby flight dynamics instrumentation and flight … · brumby flight dynamics-instrumentation and...

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Brumby Flight DynamicsBrumby Flight Dynamics--Instrumentation and Instrumentation and Flight Test ResultsFlight Test Results

Jacob CampbellJacob Campbell

Advisors:Advisors:Frank van Graas &Frank van Graas &

Maarten Uijt de HaagMaarten Uijt de Haag

Presented at:Presented at:JUP Quarterly ReviewJUP Quarterly Review

January 9January 9--10, 200310, 2003

22

OutlineOutlineOutline

Previous WorkTriple GPSAirborne Wireless LAN Repeater

Current ResearchSensorsPlanningFlight TestResults

Future Work

33

Previous Work-Short Base Line

GPS Attitude Determination

Previous WorkPrevious Work--Short Base Line Short Base Line

GPS Attitude DeterminationGPS Attitude DeterminationConducted By Matt Harris and Dr. Dan Aloi3 Marconi Allstar GPS Receiver

44

Previous Work-Airborne Wireless Internet Repeater

Previous WorkPrevious Work--Airborne Wireless Internet RepeaterAirborne Wireless Internet Repeater

55

Current ResearchCurrent ResearchCurrent Research Red - CompleteBlue - In ProgressBlack - Future Plans

• Acquisition:• Model airplanecategory

• Significantpayload

• GPS Receiver

• Data link• Compass• Brakes

• IMU• Airdata

boom

• Advanceddata collectionsystem

• ModelPrediction

Fully autonomous

Remotely Pilotedwith autopilot aiding

Aero Model Inputs

Controls EnrouteHold modes

Automatic takeoff

Accurate height

Autoland

66

Current Research – Data Wire DiagramCurrent Research Current Research –– Data Wire DiagramData Wire Diagram

Lippert Computer

PC-104300 MHz (passive cooling)

100 MB Disk on Chip

10 RS-232 Ports

10 Base T (for data

download)

Lippert Computer

PC-104300 MHz (passive cooling)

100 MB Disk on Chip

10 RS-232 Ports

10 Base T (for data

download)

Z-World Jack Rabbit 30 MHz µ-C






HoneywellStatic Pressure

HoneywellStatic Pressure

X-Bow IMUX-Bow IMU

HoneywellDynamic Press.

HoneywellDynamic Press.

Angle of AttackVane

Angle of AttackVane

Side SlipVane

Side SlipVane

CMC GPSCMC GPS

Leica 3-axis Compass

Leica 3-axis Compass

TTL, 19.2kb/s, 1 Hz Position, 10 Hz Pseudo Range and Carrier PhaseTTL, 1 Pulse Per GPS Second (PPS)

232, 19.2kb/s, Data Rate-133 Hz

TTL, 19.2kb/s, Data Rate-20 Hz

485, 19.2kb/s, Data Rate-20 Hz

Analog, Sampled at ~ 5 Hz

Analog, Sampled at ~ 5 Hz

TTL, 9.6kb/s, Data Rate ~ 3.3 Hz

PPM, 50Hz

TTL, 4.8kb/s, Data Rate ~ 8 Hz

(PPS)

(PPS)

RS-232, 115.2kb/s

RS-232, 115.2kb/s

RS-232, 115.2kb/s

DATA COLLECTIONDATA COLLECTIONTIME STAMPINGTIME STAMPINGSENSORSSENSORS

TTL->232

TTL->232

JR PCM10S RC Receiver

JR PCM10S RC Receiver PW to Serial

Converter (PIC)PW to Serial

Converter (PIC)

77

Current Research-µ-C GPS Time Synchronization

Current ResearchCurrent Research--µµ--C GPSC GPS Time SynchronizationTime Synchronization

Initialize Jack Rabbit Real Time Clock (RTC) to GPS Time Message

GPS Time Message Delayed ~ 0.6 secondsCreates an Offset between GPS Time and the Jack Rabbit’s RTC

1 32 4

1 32 4

RTC_Offset

GPS Time

Jack Rabbit Real Time Clock (RTC)

88

diff < (1-δc)diff < (1-δc)

diff ← diff - 1diff ← diff - 1

diff >= δcdiff >= δc

NO

NO

YES

YES

Mis

sed

Puls

e

Glitch

Missed Pulse & Missed Pulse & Glitch CorrectionGlitch Correction

Current Research-µ-C GPS Time Synchronization

Current ResearchCurrent Research--µµ--C GPSC GPS Time Synchronization

ISR StartISR Start

Time Synchronization PPS_Time ← (Read RTC)PPS_Time ← (Read RTC)

FIRST PPS?

YES FIRST PPS?RTC_Offset ← (ceil(PPS_Time) -PPS_Time)RTC_Offset ← (ceil(PPS_Time) -PPS_Time)

RTC_Offset ← RTC_Offset – diffRTC_Offset ← RTC_Offset – diff

diff ← (PPS_Time – PPS_TimePrev)diff ← (PPS_Time – PPS_TimePrev)

NO

δc: Jack Rabbit Clock Drift (absolute value, thus positive)

PPS_Time: Time InterruptReceived

PPS_TimePrev: Time Last Interrupt Received

RTC_Offset: Difference between GPS Time and RTC

diff: Time between Last Interrupt and Current Interrupt

PPS_TimePrev ← PPS_TimePPS_TimePrev ← PPS_Time

ISR ReturnISR Return

99

Sensor Measurement Time StampingDelays

Sensor Measurement Time StampingSensor Measurement Time StampingDelaysDelays

301~0.051.04200100LeicaCompass

~0.05

~0.05

~0.05

~0.05

n/a

Jack Rabbit Time Stamping

Delay (ms)

1222.08n/a~120JR PCM10SRC Receiver

250n/an/a250Alpha & Beta

67.20.52116.750PPT & HPA(Pd & Ps)

2.010.2600.90.8 X-Bow IMU

0n/a00CMC GPS

Total Delay (ms)

Data Transmission

Delay (ms)

Sensor Processing Time (ms)

Measurement Integration Time (ms)

Sensor

1010

Current Research - PlanningCurrent Research Current Research -- PlanningPlanning

1111

Current Research - PlanningCurrent Research Current Research -- PlanningPlanning

Avionics Platform with Brumby Hull

Avionics Platform

1212

Current Research, Flight Test

Current Research, Current Research, Flight TestFlight Test

Wire Wrap used to allow for flexibility in signal routing

GPS Antenna Inside Hull

1313

Current Research – Flight TestCurrent Research Current Research –– Flight TestFlight Test

1414

Current Research:Power ConsumptionCurrent Research:Current Research:

Power ConsumptionPower Consumption

4 Ah, 14.4 V, Li-Ion Battery (16.4 - 14.0 volts)

Measured Load: 1.1 A

3+ hours of Battery Life

1515

Current Research: Weight

Current Research: Current Research: WeightWeight

2.1 lbs.Rx bat. (2, 4-cell Nicad)

11.3 lbs.Total Payload4.75 lbs.Available

(AMA Legal, w/ fuel)

0.4 lbs.Data Boom0.2 lbs.Compass1.0 lbs.Freewave Data Transceiver1.2 lbs.Li Ion Battery6.4 lbs.Data Collection Panel

WeightDevice

Aircraft Weight Budget Payload Weight Budget

66.0 lbsMax Gross Takeoff Weight(Design Specificationsw/o fuel)

55.0 lbsMax Gross Takeoff Weight(AMA* restrictedtakeoff weight w/ fuel)

50.25 lbs.Aircraft Weight 10/23/2002(w/ fuel)

37.5 lbs.Aircraft Empty Weight

* ACADEMY OF MODEL AERONAUTICS

1616

Flight Test- October 23, 2002Flight TestFlight Test-- October 23, 2002October 23, 2002

1717

Flight Test – Gyro OutputsFlight Test Flight Test –– Gyro OutputsGyro Outputs

0 10 20 30 40 50 60 70-50

0

50

roll

rate

, deg

/s

0 10 20 30 40 50 60 70-50

0

50

pitc

h ra

te, d

eg/s

0 10 20 30 40 50 60 70-40

-20

0

20

t, s e c

yaw

rate

, deg

/s

Throttle : 75%Duration: 60 s

Straight and Level w/ Turn the last 10 Seconds

1818

Flight Test – Pitch GyroFlight Test Flight Test –– Pitch GyroPitch Gyro



1919

Flight Test – Roll GyroFlight Test Flight Test –– Roll GyroRoll Gyro



2020

Flight Test – Yaw GyroFlight Test Flight Test –– Yaw GyroYaw Gyro



2121

0 1 0 2 0 3 0 4 0 5 0 6 0 7 0

0 1 0 2 0 3 0 4 0 5 0 6 0 7 0

0 1 0 2 0 3 0 4 0 5 0 6 0 7 0t, s e c

Flight Test – Accelerometer OutputFlight Test Flight Test –– Accelerometer OutputAccelerometer Output



1

ax, g

0

-1

-2

4

ay, g

2

0

-2

4

az, g

2

0

-2

2222

Flight Test – X AccelerometerFlight Test Flight Test –– X AccelerometerX Accelerometer



2323

Flight Test – Y Accelerometer Flight Test Flight Test –– Y Accelerometer Y Accelerometer



2424

Flight Test – Z AccelerometerFlight Test Flight Test –– Z AccelerometerZ Accelerometer



2525

Future WorkFuture WorkFuture WorkData Collection Improvements

Increase IMU Time Tagging Precision and AccuracySecond Internal Counter on JackrabbitIMU Timing PulseIsolate IMU from Engine “Noise”

Add messages to convey the operational state of the JR to the PC-104 and vice-versa.Improve JR subroutine to sample Alpha and BetaGround Link and Ground Station

Sean’s Work on the 6 DOF ModelAdd a Truth Reference for Multipath StudiesSatellite Link

QUALCOMM Globalstar GSP-1620 Satellite Data Modem(see next slide)

2626

Future WorkFuture WorkFuture Work

QUALCOMM Globalstar GSP-1620 Satellite Data Modem

Power Consumption: 5.4 W max Voltage: 5.6-16 VDCDimensions: 7.48 x 2.95 x 0.68 inWeight

Modem: 6.3 oz.Antenna: 8.8 oz.

2727

AcknowledgementsAcknowledgementsAcknowledgements

Dr. van Graas (sponsor and advising)

Jamie Edwards (brumby pilot)

Sean Calhoun (controls and hardware)

Jared Kresge (hardware and programming)

Massimo Crisci (hardware and programming)

Andrey Soloviev (frequency domain analysis)

2828

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