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Autosub Autosub Mission Planning and Mission Planning and

OperationsOperations

Dr. Miles PebodyDr. Miles PebodyOcean Engineering DivisionOcean Engineering Division

Southampton Oceanography CentreSouthampton Oceanography Centre

M.Pebody@soc.soton.ac.ukM.Pebody@soc.soton.ac.uk

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OverviewOverview

EquipmentEquipment Pre-Mission PlanningPre-Mission Planning Mission Preparation and Mission Preparation and

InitiationInitiation Mission End and Post MissionMission End and Post Mission

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EquipmentEquipment

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Equipment: Equipment: Computing ResourcesComputing Resources

Three Networked Three Networked PCsPCs

• Mission programming, Mission programming, mission management and mission management and vehicle telemetry.vehicle telemetry.

• Acoustic TrackingAcoustic Tracking

• Data ProcessingData Processing

Tershelling April 2000Tershelling April 2000

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Equipment: Equipment: On Surface CommunicationsOn Surface Communications

Lonworks VHF Radio Modem (range Lonworks VHF Radio Modem (range 0.5Km)0.5Km)

Ethernet VHF Radio Modem (range 0.5Km)Ethernet VHF Radio Modem (range 0.5Km) Orbcomm Satellite CommunicationsOrbcomm Satellite Communications Argos Satellite TrackingArgos Satellite Tracking

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Equipment: Equipment: Subsurface CommunicationsSubsurface Communications

23-33KHz Acoustic Tracking, 23-33KHz Acoustic Tracking,

Telemetry and CommandsTelemetry and Commands

10-14KKz Tracking 10-14KKz Tracking (telemetry in development) (telemetry in development)

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Pre-Mission PlanningPre-Mission Planning

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Pre-Mission PlanningPre-Mission Planning

Mission RequirementsMission Requirements Mission NavigationMission Navigation Control ModesControl Modes Autosub Safety IssuesAutosub Safety Issues The Mission End - The Mission End -

RecoveryRecovery

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Mission RequirementsMission Requirements

Instruments/sensorsInstruments/sensors Data samplingData sampling Area of operationArea of operation Vehicle critical factorsVehicle critical factors

• Power availabilityPower availability• Depth ratingsDepth ratings

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Mission NavigationMission Navigation

Example: track of 110 km mission off Fort Example: track of 110 km mission off Fort Lauderdale. Coast, Florida.Lauderdale. Coast, Florida.

Waypoint selectionWaypoint selection Co-ordinate SystemCo-ordinate System

• Cartesian (X/Y metre offset)Cartesian (X/Y metre offset)• Polar (latitude/longitude)Polar (latitude/longitude)

Navigation Mode Navigation Mode SelectionSelection• Heading onlyHeading only• Heading to positionHeading to position• Follow track between two Follow track between two

positionspositions

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Control Modes: Control Modes: Depth/Altitude ControlDepth/Altitude Control

0

5

10

15

De

pth

(m

)

0 300 600 900 1200 1500 1800 2100 2400

Time (s)

Vehicle depth

Water depth

Depth controlDepth control Altitude control - terrain Altitude control - terrain followingfollowing

Autosub can also be programmed to profile Up/Down at Autosub can also be programmed to profile Up/Down at constant pitch anglesconstant pitch angles

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Mission Safety IssuesMission Safety Issues

• In water obstaclesIn water obstacles• Terrain - vehicle pitch controlTerrain - vehicle pitch control• Surfacing zonesSurfacing zones• Mission depth and altitude limitsMission depth and altitude limits• Emergency abort timeoutsEmergency abort timeouts

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Mission Preparation and Mission Preparation and InitiationInitiation

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Mission Preparation and Mission Preparation and InitiationInitiation

Mission ScriptMission Script Configuration ScriptConfiguration Script Mission Script CheckingMission Script Checking Pre-Launch TasksPre-Launch Tasks Post-Launch / Pre-Start Post-Launch / Pre-Start

TasksTasks

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Operations: Operations: Mission PreparationMission Preparation

Mission ScriptMission Script

EditorEditor

ConfigurationConfiguration

EditorEditor

Control parameters Control parameters Sensor parametersSensor parametersSafety limitsSafety limitsEAS timers + limitsEAS timers + limits

MissionMission

CompilerCompiler

WarningsWarnings

Go! Go!

StopStop

MissionMission

CommanderCommander

+ Monitor+ Monitor

History FileHistory File

RadioRadio

ModemModemDown-loaderDown-loader

Mission SimulationMission Simulation

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Operations: Operations: The Mission ScriptThe Mission Script

// When satisfactory GPS fix has been acquired dive and track // When satisfactory GPS fix has been acquired dive and track follow: follow:

// Set timeout to 500 seconds.// Set timeout to 500 seconds.

WHEN( GotGPSfix)WHEN( GotGPSfix) // When GPS fix acquired ………// When GPS fix acquired ………

Timer( 500),Timer( 500), // Set timeout of 500 seconds.// Set timeout of 500 seconds.

Depth( 10),Depth( 10), // Set depth mode to 10 metres.// Set depth mode to 10 metres.

MotorPower( 400), MotorPower( 400), // Set motor mode to Power 400 // Set motor mode to Power 400 Watts.Watts.

PositionP( N:56:27.5, W:5:29.4); PositionP( N:56:27.5, W:5:29.4); // Set position mode and // Set position mode and demanddemand

// Next line, when reached end of the track ……// Next line, when reached end of the track ……

WHEN( GotPosition)WHEN( GotPosition) // When Got there (// When Got there (OR timeoutOR timeout))

……… ………

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Operations: Operations: The LaunchThe Launch

•Early launches through ship’s ‘A’ Frame.Early launches through ship’s ‘A’ Frame.

•Now we use a gantry system.Now we use a gantry system.

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Operations: Operations: Monitoring unattended Monitoring unattended missionsmissions

GPSGPSpositionposition

OrbcommOrbcommdata linkdata link

Terschelling Autosub campaign Terschelling Autosub campaign March 00March 00

Text messageText messageon cell phoneon cell phone

GPSGPS

OrbcomOrbcommm

Status Status messagemessage

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Mission End and Post MissionMission End and Post Mission

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Mission End: Mission End: Autosub Relocation.Autosub Relocation.

Local ARGOS tracking to horizonLocal ARGOS tracking to horizon Surface radio telemetry within 0.5 KmSurface radio telemetry within 0.5 Km Acoustic Telemetry within 1 Km (soon Acoustic Telemetry within 1 Km (soon

6Km)6Km) Acoustic tracking within 8 KmAcoustic tracking within 8 Km

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Mission End and Post MissionMission End and Post Mission

Logger Data RecoveryLogger Data Recovery Autosub RecoveryAutosub Recovery Navigation Postprocessing and Navigation Postprocessing and

Engineering data examinationEngineering data examination

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The EndThe End

Dr. Miles PebodyDr. Miles PebodyOcean Engineering DivisionOcean Engineering Division

Southampton Oceanography CentreSouthampton Oceanography Centre

M.Pebody@soc.soton.ac.ukM.Pebody@soc.soton.ac.uk

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Autosub Systems: Autosub Systems: NavigationNavigation

GPS or DGPS fixes on the surface update the position GPS or DGPS fixes on the surface update the position estimate.estimate.

Special Navstar GPS antenna overcomes problems Special Navstar GPS antenna overcomes problems of washover on tail mounted antenna.of washover on tail mounted antenna.Broadcast (300 kHz) DGPS corrections used.Broadcast (300 kHz) DGPS corrections used.

Uses RDI 300kHz Doppler sonar (250 m range) for Uses RDI 300kHz Doppler sonar (250 m range) for velocity.& Seatex MRU6 compass for rotation into earth velocity.& Seatex MRU6 compass for rotation into earth co-ordinates.co-ordinates.

Biggest problem is heading dependent compass errors. Biggest problem is heading dependent compass errors.

Errors can be substantially reduced to about 0.5-1% of Errors can be substantially reduced to about 0.5-1% of distance travelled with calibration.distance travelled with calibration.

Calibration involves a short box mission.Calibration involves a short box mission.

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Autosub Systems: Autosub Systems: Heading ControlHeading Control

• HeadingHeading

• Line Of Sight Line Of Sight - (- (Head towards demanded Waypoint)Head towards demanded Waypoint)..

• Track FollowTrack Follow- (- (Follow Straight Line Track Between Follow Straight Line Track Between

Two Waypoints). Two Waypoints).

Modes of Operation.Modes of Operation.

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Future DevelopmentsFuture Developments

Integrated mission planning tools including mission Integrated mission planning tools including mission simulation and replay.simulation and replay.

Modify Mission Control and Emergency Abort for the Modify Mission Control and Emergency Abort for the more complex environment of under-ice missions.more complex environment of under-ice missions.

Power source - fuel cells, semi-fuel cells.Power source - fuel cells, semi-fuel cells.

Improved Collision Avoidance in the horizontal Improved Collision Avoidance in the horizontal

plane.plane. Improved Navigation. Use Ring Laser Gyro based Improved Navigation. Use Ring Laser Gyro based

INS. From 1% to 0.1% of distance traveled.INS. From 1% to 0.1% of distance traveled.

Improved Acoustic Communications and Location.Improved Acoustic Communications and Location.