Dynamically Positioned and Thruster Assisted Position Moored Vessels

Transcription

1 Dynamically Positioned and Thruster Assisted Position Moored Vessels Professor Asgeir J. Sørensen, Department of Marine Technology, Norwegian University of Science and Technology, Otto Nielsens Vei 10, NO-7491 Trondheim, Norway 1

2 Outline Motivation/Background Dynamic Positioning Applications Functionality Class Requirements 2

3 Guidance, Navigation and Control Positioning systems: Guidance, navigation and control for automatic sailing and maneuvering Dynamic positioning Thruster assisted position mooring 3 Main function: To keep a vessel exposed to wave loads wind loads current loads on specified position and heading coordinates by means of proper action of the thruster and/or propulsion system

4 Dynamic Positioning - Applications The three big marine industries.: Shipping & Cruise Offshore Fisheries and Aquaculture 4

5 5 Dynamic Positioning - Vessel Types

6 Functionality: Control Modes Station keeping models Marine operation models Slender structures Multibody operations Manoeuvring models Linearized about some U o Sea keeping Motion damping High speed tracking/transit Low speed tracking Marked position Station keeping Speed [knots]

7 Positioning Systems Dynamic Positioning (DP/DYNPOS) Position Mooring (PM/POSMOOR) Autopilot / Tracking Joystick Systems Manual Thruster Control System 7

8 Positioning Control Functionality MRU s WIND SENSORS DGPS HPR DPCON-A MTC DPCON-B DPCON-C DGPS Initial Mode GYRO s ARTEMIS Manual Mode PRINTER Semi Auto Mode DPCAB-A CONTROL NE TW ORK Auto Mode DPCAB-B DPCAB-C Damping Control DP TRA INING SIMULATOR Station Keeping DRA UGHT SENSORS FIELDBUS NE TWORK Marked Position HPR TRANSDUCER Way-point Tracking Optimal Heading Control Roll and Pitch Damping Optimal Setpoint Chasing 8

9 DP Control System Features Selectable Wind Feedforward individually in surge, sway and yaw. Selectable Low, Medium and High gain in all operational modes. Selectable reference velocities in tracking operations Selection of arbitrarily rotation point. Automatic or manual sea state selection for improved performance in varying environmental conditions. 9

10 Dynamic Positioning DP Init Manual Semi-Auto Auto Init SK surge SK sway SK yaw Stat Keep Y v(sway) Man Mark surge Damp surge Mark sway Damp sway Mark yaw Damp yaw Mark Pos Damp X u (surge) Z r (yaw) 10

11 Positioning Control Architecture THRUSTER SETPOINTS MEASUREMENTS THRUST ALLOCATION Process Plant SIGNAL PROCESSING POWER MANAGEMENT SYSTEM POWER LIMITS ADAPTIVE LAW VESSEL OBSERVER COMMANDED THRUST CONTROLLER VESSEL MOTIONS OPTIMAL SETPOINT CHASING REFERENCE MODEL OPERATOR 11

12 Position Mooring Purpose: - Give Thruster Assistance in position and heading keeping - Damping Function - Keep fixed position and heading - Tailor-made solutions for special applications Turret Anchor lines Seabed 12

13 Petrojarl Varg FPSO Turret Anchor lines Seabed 13

14 POSMOOR System UHF LINK ARTEMIS MRU WIND SENSORS DARPS TURRET DYNAMIC POSITIONING POSITIONING/ MOORING GYRO PROPULSION AZIPOD MASTERBUS NETWORK SAFETY SYSTEM DRAUGHT SENSORS PROPULSION AZIPOD 14 Thruster Assisted Position Mooring (POSMOOR) System: Thruster assistance for position and heading keeping of anchored vessels

15 Autosail / Tracking Purpose: Long Distance Sailing and high speed tracking Functionality: Autopilot Mode Course Keeping and Course Change Course Correction Function Correction of course track Tracking Function High speed way-point tracking Handles any type of thruster / rudder configurations Can use pitch / RPM / rudder / azimuth angle as control input 15

16 Manual Thruster Control Purpose: Remote control of the propulsion system Operator controls - RPM / pitch - Azimuth angle 16

17 Advisory Systems Posmoor simulator and consequence analysis DP consequence analysis and simulator: Analysis of the vessel s ability to keep position subject to on-line, prevailing condition Single thruster failures Most sever power failures 17

18 Standard DP measurements Position reference systems: DGPS Hydroacoustic Artemis (Microwave) Laser Taut-wire (Riser) Heading and yaw rate: Gyrocompass / GPS Roll and pitch angle: Vertical reference units (accelerometers, gyros) 18 Wind speed and direction: Anemometers

19 Measurements - challenges Challenges: Time delays, synchronization of multiple signals Measurement resolution and update rate Noise level and nature Error handling Multiple measurements: Weighting and voting Inertial Navigation Systems (INS) More use of accurate instruments for roll / pitch, Vertical motion and horizontal acceleration. Can improve measurement availability, accuracy and total system integrity Litton LN 200 IMU 19

20 Position reference systems SATELLITE NAVIGATION SYSTEM (DGPS / GLONAS) SURFACE REFERENCE SYSTEM TAUT WIRE HYDROACOUSTIC POSITIONING SYSTEM 20

21 Signal alignment and noise compensation GPS ANTENNA VRU HPR TRANSDUCER 21 All position measurements are transformed to one common reference point on the vessel - center of gravity / midship

22 DP Class Requirements IMO Equipment Class DnV Lloyds ABS Not applicable Dynpos AUTS DP CM DPS-0 Class 1 Dynpos AUT DP AM DPS-1 Class 2 Dynpos AUTR DP AA DPS-2 Class 3 Dynpos AUTRO DP AAA DPS-3 22

23 DNV DP Class requirements 23 Table C1 System arrangement Subsystem or component Minimum requirements for class notations AUTS AUT AUTR AUTRO Generators and prime movers No-redundan- No-redundan- Redundancy in Redundancy in technical decy**) cy**) technical design sign and physical separation (separate compartments) Switchboard 1**) 1**) 1 with bus-tie 2 in separate compartments Power system Bus-tie breaker 0**) 0**) 1 2, 1 breaker in each MSB Distribution system No-redundan- No-redundan- Redundancy in Redundancy in technical decy**) cy**) technical design sign and physical separation (separate compartments) Power management No**) No**) Yes Yes Redundancy in technical Redundancy in de-sign and physical Arrangement of thrusters No-redundancy No-redundancy technical design separation (separate Thrusters compartments) Single levers for each thruster at main DP-control centre Yes Yes Yes Yes Positioning Control System Sensors Auto control: number of compu-ter systems Manual joystick with control: auto heading inalternate control station No Yes Yes Yes 2+1inalternate control sta- Position reference systems tion Wind External sensors VRS 1 1 2*) 2 Gyro compass in alternate control station UPS 2+1inseparatecompartment Printer Yes Yes Yes Yes Alternate control station for positioning control No No No Yes back-up unit *) Where necessary for the correct functioning of position reference systems, at least three vertical reference sensors are to be provided for the notation AUTR **) If any part of the vessel s normal electrical power supply system, then Pt.4 Ch.8 applies.

24 DP Class 0 Configuration WIND SENSOR DYNAMIC POSITIONING SYSTEM MTC MRU GYRO DGPS PLANT NETWORK CONTROL NETWORK DP CONTROLLER UNIT FIELDBUS NETWORK MAIN PROPELLER w / RUDDERS TUNNEL THRUSTER AZIMUTH THRUSTER AZIPOD 24

25 DP Class 1 Configuration WIND SENSOR DYNAMIC POSITIONING SYSTEM MTC HPR MRU DGPS GYRO CONTROL NETWORK DP CONTROLLER UNIT FIELDBUS NETWORK MAIN PROPELLER w / RUDDERS TUNNEL THRUSTER AZIMUTH THRUSTER HPR TRANSDUCER 25 AZIPOD

26 DP Class 2 Configuration MRU s GYRO s WIND SENSORS DGPS DPCON-A MTC DPCON-B DP CQA/SIM HPR PRINTER ARTEMIS CONTROL NETWORK DPCAB-A DPCAB-B FIELDBUS NETWORK HPR TRANSDUCER 26 TC DRAUGHT SENSORS

27 DP Class 3 Configuration MRU s WIND SENSORS DGPS HPR DPCON-A MTC DPCON-B DPCON-C DGPS GYRO s ARTEMIS PRINTER CONTROL NETWORK DPCAB-A DPCAB-B DPCAB-C DP TRAINING SIMULATOR FIELDBUS NETWORK DRAUGHT SENSORS 27 HPR TRANSDUCER

28 POSMOOR ATA Configuration WIND SENSORS PMCON-A MTC PMCON-B PMANA MRU s DGPS HPR GYRO s PRINTER ARTEMIS TURRET CONTROL NETWORK PMCAB-A PMCAB-B FIELDBUS NETWORK DRAUGHT SENSORS HPR TRANSDUCER 28