Deift University of Technology
Onboard Experiments on Weather
Vaning Dynamic Positioning System
J.A. Pinkster, H. Hagiwara, R. Shoji and
H. Fukuda
Report 1245-P
November 2000
Presented at the 2nd International Congress
on Maritime Technological Innovations and
Research, 8-11 November 2000, Cadiz, Spain
TU Deift
Faculty of Mechanical Engineering and Marine Tecisnology Ship Hydrornechanics LaboratoryriÚime
ÇI dieà.y
I
F.Piniella
-
A. Bocanegra (UCA)
J. Olive/Ia
-
R. Rdguez-Martos (UPC)
SERVICIO DE PUBLICACIONES
-
UNIVERSIDAD DE CADIZInternational
Congres s
on Maritime
Technological
Inn ova
and Researc
1j
p re e n
Cádiz, 8-11 November 2000
2" International Congress
on Maritime
Technological In novations and Research.
"NEWMARITIME IMPULSES IN
THE PRESENCE OF A NE W CENTUR Y"
THEME A.
Maritime Way for Sustainable Mobility
PANEL Al: VESSEL CONTROL AND SAFElY
PANEL A2: SHIP AND TECHNOLOGY
PANEL A3. ENVIRONMENTAL MANAGEMENT
THEME B:
Efficiency and Quality
PANEL Bi: MARITIME TRANSPORT LA W
PANEL B2: TRANSPORT, SHIPPING AND INTERMODALITY PA NEL B3: EFFICIENCY1NNA VIGA TION SYSTEMS
THEME C:
Human Factors
PANEL Cl. BEHA VIOUR AND TRAINING. MARITIME EDUCATION
PANEL C2: ERGONOMICS AND MEDICINE ASPECTS
PANEL C3. MULTILINGUAL CREWS. MARITIME ENGLISH
THEME D.
Marine Resources
Arturo Castaño
Organized by
In cooperation with
The International Congress on Maritime Technological Innovations and Research was born as
an initiative from the Department of Nautical Sciences and Engineering of the Universitat
Politècnica de Catalunya (TJPC) to the development of shipping a challenging action over the
past few years. Today, this Conference is intended to improve important aspects such as
maritime training, new technologies and R&D programs, together with management systems,
among others. The 2" Congress will serve as a forwn for cooperation among the d[ferent national and international institutions involved in Maritime Education.
Proceedings edited by:
Francisco Piniella Ana Bocanegra Juan Olivella
Ricardo Rdguez. -Martos
nd
International Congress on
Maritime Technological Innovations and Research.
Universidad de Cádiz
Facultad de Ciencias Náuticas
Under the patronage of
FOR OSUR - Southern Maritime & Industrial Forum (Cádiz)
Universitat Politécnica de Catalunya
Departament de iéncia i Enginyería Nà.tiques
Servicio de Publicaciones - Universidad de Cádiz 2000 ISBN 84- 7786-669-4 (Paperback)
ISBN 84- 7786-670-8 (CD-Rom)
afilie edition: the editors of flic papers: cae!: author
Honour Gommittee.
Exc° Sr. Manuel Chaves Presidente Junta de Andalucía
Exc° Mr. William O'NeiI
Gen. Secr. International Maritime Organization
Exc° Sr. Rafael Román Presidente Diputación de Cádiz
Exc° Magf Dr. Guiller,no MartíneMassanet
Rector Universidad de Cádiz Exc° Magic° Dr. JaumePagés
Rector Universitat Politècnica Catalunya
llm° Sr. Rafael Barra
Presidente Autoridad Portuaria Puerto Bahía de Cádiz Sr. Joaquin Buelga
Scientific Committee
William Tetley (Univ. McGill Montreal) José LuL Rodríguez-Carrión (Univ. Cádiz) Jens Froe.se (iSSUS Hamburg)
Dieter Lemburg (ISSUS Ham burg) Juan José Achútegui (Univ. Cantabria)
Emilio Egula (Univ. Cantabria) Gli nter Zade (Mani. Univ. Malmöe) Ricard Marl (UPC, Barcelona) Francisco Montero (Univ. Cádiz) Mercedes Herrera (Univ. Basque ountiy Diego Sales (Univ. Cádiz)
Francisco Casanueva (Univ. Cádiz) Juan Zafra (Univ. Cádiz)
Antonio García-Morilla (Univ. Cádiz) Peter Trenkner (Wismar Univ. Rostock) Manuel Jesús Lápez (Univ. Cádiz) José Antonio Hernando (Univ. Cádiz) Alfredo Caso (Univ. Cádiz)
Conference Organizing Committee
Conference Chairman: Francisco Piniella Depu4:
Juan Moreno
Coordinator Org. Committee: Ana Bocanegra
Committee Members: José Antonio Iglesias
Ricard Marl
Sebastián García-León
Juan Carlos Rasero
María Zambonino Pedro Nogueroles Rica rd Jaime
Manuel Barea Juan Luis Pulido
Ricardo Hernández
Conference Secretariat:
Julio Terrón
Organizing Secretariat and Public Relations: Antonio Salmerón (UCA)
Yolanda Alcázar (UPC)
Webmaster(http://www.uca.es/facultad/nauticas)
Sponsored by
IPUTACOf4 DE cADIZ Dputación deCadiz
LL Wt CAD
i
itb
Cadiz Bay Pori Authority UMVERSIDAD DEC4bIZ Consejo Social Vicerrectorado de investigación Vicerrectorado de Extensión Universitaria Vicerreclorado de Relaciones internacionales Servicio de PublicacionesDepartamento de Ciencias y Técnicas de la Navegación, Máquinas y Motores Térmicos, Teoria de la Señal y (;'amunicaciones
Departasnesto de Derecho Mercantil
COMME
(Spanish Ship Officers Association) ETEM4R
(Maritime Technical Consulting, Barcelona)
ITB
inspección Técnica de Buques
JUNTA DE ANDALUCÍA Consejeria de Educación y Ciencia Consejería de Agricultura y Pesca
Special thanks to:
Rafael Barra Rafael Boloix Francisco Montero Olga Bosquez Felicidad Rodríguez Antonio García-Morilla Isidro González Rafael PadillaMiguel Angel Pendón Joaquín Buelga
José María Molina
Albino Pardo
Rafael Padilla
Antonio Bocanegra
Antonio M Padrón
Teodoro López-Moratalla Rafael Rdguez. -Sandez Juan Antonio Granados Ignacio Moldes
José María Gracia
Carlos Gentil Yolanda Alcázar
Montserrat Margalef
Jerónimo Ruiz Antonio Cabrera
PRESENTACIÓN Y
AGRADECIMIENTOS
Este 2° Congreso Internacional de hivestigación e Innovaciones Tecnológicas en el Ambito Marítimo viene a cerrar los actos que la Facultad de Ciencias Náuticas ha venido celebrando en este año 2000, como fecha conmemorativa del 500° Aniversario del Colegio de Pilotos Vizcaínos k Cádiz, primera institución de enseñanza náutica de España. Asimismo, la iniciativa de celebrar un congreso de estas características, supone un punto departida en el relanzamienio de los estudios relacionados con el ámbito marítimo en la Universidad de Cádiz. En el capítulo de agradecimientos es de destacar, en primer lugar, el patronazgo dei Congreso realizado por el Fom Industrial y Marítimo del Sur (FOROSUR). Junto a éste, también es de agradecer ei inestimable apoyo recibido por pane de dos empresas del sector como son liB (inspección Técnica de Buques) y CETEMAR (Cenino de Estudios Técnico-Marítimos, Barcelona) así como la cooperación del resto de las institucionesfinalmente implicadas: Universidades e Institutos participantes, Organización Marítima Internacional (0Ml), Junta de Andalucía, Diputación Provincial de Cádiz, Colegio de Oficiales de la Marina Mercante (COMME), y Autoridad Portuaria de la Bahía de Cádiz. Nos gustaría asimismo agradecer a todos los profesores, profesionales y participantes por su esfuerzo en acudir a esta reunión)' compartir con un público internacional sus trabajos e interesantes investigaciones. El Comité Organizador sinceramente os desea a todos y todos una estancia en Cádiz que os resulte confortable, grata yprovechosa. Y recuerden que precisamente aqui en Cádiz, hace quinientos años, en una capilla de una Iglesia, pa se adiestraban a los marinos que iban a traer de América nuevos vientos, nuevas ideas, y nuevas formas de entender el progreso de los
hombres.
¡Bienvenidos a Cádiz!
PRESENTATION AND
A CKNO WLEDGEMENTS
This 2" International Congress on Maritime Technological Innovations and Research is sneant to be the concluding event that the Faculty of Nautical Sciences has been organising throughout 2000. To coninemorate the 500m anniversary of the College ofBiscain Masters in Cadiz, the veryjirst institution in Spain providing studies and trainingfor seafaring. Likewise, the initiative ofholding a Conference such as this one aims to be the starting point that supports and re-launches those degrees related to the maritime world and profession at the
University of Cadiz.
FOROSUR, "Southern Industrial an Maritime Forum' is to be openly and gratefully acknowledgedfor their generous and collaborative efforts in facilitating the organisation of this Conference.
Together with FOROSUR, other institutions, organisations and maritime firms are tobe acknowledgedfor their support and cooperation:
Universities, International Maritime Organisation (1MO), Regional Government of Andalucia, Provincial Government of Cadiz,
Spanish Ship OfficersAssociation (COMME), the Port Authority of the Bay of Cadiz, Vessels' Technical Inspection Service (1113), and Maritime Technical Consulting, Barcelona
(CE TEMA R).
All those schokrs, lecturers, professionals, and participants in general are thanked for their
efforts in attending, presenting their work and sharing their interesting research with a
world-wide audience.
The Organising Com,nittee sincerely hopes you all enjoy your paricipation in the Conference and make the most ofyour stay in this city. And remember that it vess precisely here, in a chapel in Cadiz, that 500 years ago seafarers were already trained; those seafarers that,from America, would eventuahv bring along new hopes, new thoughts and new ways of understanding human progress.
Welcome to Cadiz!
Francisco Piniella.
INDEX OF PAPERS I ÍNDICE DE TRABAJOS
THEME A: MARITIME WAY FOR SUSTAINABLE MOBILITY
Panel Al: Vessel Control and Safety
AC. BERMEJO, A.J. RJLEO, Ships in distress effective location and identification: a duty for current Maritime Safety
T. IsEKI, D. TERADA, K. O-ITSI4 Study on Stochastic Guidance System for Heavy Weather Operation
F.J. SANCHEZ, M. OFRA, JR. SAN CRISTOBAL, J.L. MJLERO, R. MONTES, Statistical
calculation of the ship's speed
T. STUPAK, The Maritime Safety System on Polish WatersCAF. IIEAL, Probabilistic cargo mechanics: study of the ship's motions effect on the
cargo shifting onboard a Ro/Ro ship
R. FERREIRO, C.A.F. MEAL, Contribution to real time stability monitoring in waves based in FFT algorithm
A CONSEGLIERE M.J. LÓPEZ, RD and H-inf Tuning Methods for Ship Autopilot C. PEREZ, F. PINIELLA A.G. DE LA CRUZ, Statistical analysis of PSC Inspections: Inefficiency or inadequate procedures?
F.J. 'vELASCO, E. LÓPEZ-GARCLA Predictive Control of Ship Steering Autopilots
J. LLINARE s-ALVAREZ, MA PLONSO-POA, R. GARCIA-IVtNDEZ, A. CAMBLOR-ORDIZ, The
Kinetic Energy of the Ship in the anchoring manoeuvre
Z. SZOZDA, The concept of application of fuzzy sets theory in order to calculate stability
characteristics of ro-ro passenger ferries
J. OLIVELLA, The need to control the ship's stability in Port Operations E. CUETO-PUENTE, F.J. \,LASCo-GONZALEZ, Variable drive steering system A CONSEGLIERE, M.J. LÓPEZ, Nonlinear H-inf Control of Ships
Panel A2: Ship and Technology
MA DA FONTE, lvtM. DE FREITAS, The effect of torsion on fatigue crack growth rates on
propeller shafts with semi-elliptical surface cracks
J.H. JORDE, M.E. MNSTAD, The effect of Hull Separation on High Speed Catamaran
Resistance
J. CARDONA, MA RODRIGUEZ, F. M\NTILLA, Marine Electrical Machines Fault
Prediction
P.K. PAL, L.J. DOCTORS, D. ACOCK, Preliminary Design of High-Speed Catamaran
Ferries
MANDA, J.M. DE LA CRUZ, J.M. DIAz, R. RUIPEREZ, Interval Modelling of High Speed Craft for Robust Control
A &SCEGLIA, A. PACIOLLA, On the first design of motorship's propellers
MNAMI, K. 9-I0JI, Estimation of wave making resistance by wave analysis ship at
sea
R. FERREIRO, R. BORRAS, Design study of a torque feedback type steering gear
R. RODRIGUEZ-VALERO, G. DE MELO-RODRÍGUEZ, AA RODRIGUEZ-FERNÁNDEZ,
J. CARBIA-CARRIL, E. IRTELAVAA.MONDE, Detection of the cause of one problem
through a cause-effect diagram
AA RODRIGUEZ-FERNÁNDEZ, R. RODRIGUEZ-VALERO, G. DE VELO-RODRÍGUEZ,
J. CARBIA-CARRIL, Detection and automatic diagnosis of mechanical failures at the
present time
I. DE LA LLANA, M. CLEMENTE, J. 'SALA, A DAVALILLO, M. CUESTA, A. KOLB, Behaviour of
the KoIb Vila Propulsion System mounted in a ship model
M. SALVA Application of the infrared thermography as a loss prevention tool in the
operation of naval machinery
design technique
M. POPEK, M. RUTKOWSKA, Z. MCI-tALOWSKI, Application of the Japanese Liquefaction
Potential Test
J. CORBERA, X. MARTINEZ DE S, Oil spill detection, modelling and alarm systems: A
critical view
JA. CAsLA, J.L. LARRABE, MA GÓMEZ, Overvoltage under decoupling conditions in
electrical propulsion systems. Analysis, results and make up solutions
FILIPOwIcZ, Decision support for loading vessels- selected numerical problems
M. HARO, C. SANZ, System of Aid to operator of engine room for the control of fuel viscosity
J. MARTINEZ DE LA CALLE, J. GÓNZALEZ-PEREZ J. ASTONO-FAVERO, M. MARTINEZ-GCIA,
Thrust measure on Marine Propeller using a strain gages technique
Gu, R. CHEN, T. FJAN, Long Term Wave Data and their influence on Design Values of Wave Loads of Ships
M.L. GANDARIAS, M.S. BRUZÓR C. FV1JRIEL, Symmetry Analysis and Solutions fora Perturbed KdV Equation for Fluids
C. CORRALES, J. TERRÓN, C. SANZ, Automation of Fuel Transfer System in a Vessel
J. CARBIA, R. RODRIGIJEZ-VALERO, G. DE rtLo,A. RODRIGuEZ-FDEZ, Detection of failures
through the analysis of shock pulses in engines submitted to a variable charge rate
J. KozAiç Fatigue properties of girders' intersection
R. RODRIGUEZ-VALERO, AA RODRIGIJEZ-FDEZ, E. RRTELA, G. DE IVtLO, Weibull's
Probabilistic Graphic in the Application of the Reliability in the Equipment MOYANO, F.J. 'LAScO, L. BRAvo, Obtaining Parametric Wave Models
M. SUFFO, R. GÓMEZ-ORTIZ, M. SANCHEZ-CARRILERO, M. ÇtVAREZ-ALCÖR M. MARcos,
Using Nurbs Surfaces in CAGSD
CAYUELA, Present criteria for ships restoration: the "Saltillo" as an example of
maritime heritage conservation
Panel A3: Environmental Management
E. EGUIA, B. GARCIA A TRUEBA, J.J. AMIEVA,MA GRÓN, B. RIO-CALONGE, M. RUIZ, M. \LO,
Study of Copper Oxinate and Tetrachloroisophthalonitrile action used as active
substances in scale preventer patents with vinyl and chlorinated rubber bases
applied over artificial framings placed at the Santander Bay
E. EGUIA, MA GRÓR J.J. AMIEVA, T.F. 'ViDART, J.A. BEZANILLA, F.M. 01-ERO,
B. RIO-CALONGE, M. RUIZ, Use of Peracetic Acid as Biocide in Heat Exchangers -Condensers for the elimination of Biofouling
E. DIAZ, P. LANDA, J. GJNZALEZ, J.L. ARANA, Effects of Polystyrene on the Gel
Formation of a Block Copolymer
S. NÌGRA-MACCONO, B. RIO-CALONGE M. RUIZ, MA GIRÓR I. TEJERO, J.J. AMIEVA,
Solid Waste from Ship
SW. CAVALARI-JUNIOR, O. CARVALHO-JUNIOR, The environmental implications of a
marina: A case study
O. CARVALHO-JUNIOR, R.M. RODRIGUES, The planning, education and developing of coastal marinas in the Santa Catariria Island, Brazil
M. CARRASCO, J.L. GARCIA4VkDRALES, D. SALES, F. LÓPEZ-AGUAYO, Bioavailability of
Zinc in sediments of the Bay of Cádiz
A BMLIÑA, E. RODRIGUEZ, JA SANTABALLA, A. \AZQUEZ G. CARRERAS, J.F. CASANUEVA,
Optimization of Pollutant Separation Processes in Combustion Gases as regards the
inertization of Tanks and the Marine Environment
E. RODRIGUEZ, A BAALIÑA, JA. SANTABALLA,A \AZQUEZ, G. CARRERAS, J.F. CASANUEVA,
Study of Pollutant Separation Systems for Combustion Gases: Marine Applications
J.M. JÓDAR, J.J. tVtJÑOZ-PEREZ, J.M. GuTIERREz-MAS, J.M. MDRENO, Incidences and
efficiency in the process of transporting subacuatic sand to beach regeneration in
some places of the Cadiz atlantic coast
A DOLGPOLOW, A WDLSKI, DGPS system improves accuracy of bathymetric and
dredging work in West Pomerania
AJ. REGUERO-HUERGA, JA. GARCIA-MAZA, R. GARCIA-fVNDEZ, A. CAMBL0R-C*DIZ,
A batimetric study of the mouth of the river Nalon (Asturias, northeast of Spain). Adaptation to the peculiarities of the area
THEME B: EFFICIENCY AND QUALITY
Panel BI: Maritime Transport Law
R. MARI, Influence of the Maritime Environment on the casuistry oforganised crime
W. )Nc, C. LIANG, Tests of materiity for duty of disclosure:a study of Chinese and English marine insurance law
O.J. OYEDOKUN, Provision of Inland Waterways Transport Services as an effort towards poverty alleviation: A case study of Southeastern part of Nigeria
A ,RBOLI-JNZAZ, E. 1LÓN-RoDRIGUEZ, E. fvELCHOR-GZLEZ J.M. MARTINEZ-MAYAM
Juridical naturalia of the corsican in Spanish maritime law
CMMAÑO DE PPAMBURU, Civil liability in the case of maritimecarriage of nuclear materials
Panel B2: Transport, Shipping and lntermodality
F.J. JNTERO-LL4CER, A A'IORAY-LÓPEZ, PSC vs. FOC: What about Safety?
AC. PAIXAO, The concepts of flexibility and agility from an intermodality point of view ACASSONE, R. GUPONI, I. ZOTTI, New lines for a low wash motorboat for public
passenger transport in Venice
J. FERREIRA DA SILVA, Maritime Transport of Nuclear Material in the North -East
Atlantic Waters8
J. OLIVEIRA, Principal component analysis for the evolution of the countries, economic
development of regions, delocalisation of merchant fleets and flags of convenience
DE MELO-RODRIGUEz, AA R0DRIGuEz-FDEz, R. RODR!GUEZ-VALERO, J. CAROlA-CARRIL,
Centralization of the Maintenance of Large Shipping Industries as guarantee of their optimization
P. Lois, J. WANG, A. WALL, T. RU)croN, Consumer attitudes to cruise tourismand
fundamental considerations of competitions at sea in Cyprus and Mediterranean regions
C. PEREZ-LABAJOS, J.R. SAN CRISTOBAL, J. SARABIA, B. ANCO, J. ESTEBAN, F.J. GMEZ,
Economic Impact on the Recreational Fleet on the Community of Cantabria
Z. MCRALOWSKI, K. KIIATKOWSKA-SIENKIEWICZ M. RUTKOWSKA, K. BARCEWICZ, New
criteria of separation of Oxidizes and ammonium salts in Marine Transport A SM ITH, Privatization of Water Transportation Systems
S.U.JATAU, Dangerous Cargo: Need for proper management at sea
J.M. EZOIJERRA, K. INTXAUSTI, L. MRURI, J. QNZALEZ, ASAPP: AutomaticContainer
Transport System in Harbour Terminals
J. WALLISEF F. PINIELLA An approach to a model of Maritime Traffic in the Straitof
G bra Itar
J. MDNEDERO, J.C. RASERO, F. PINIELLA, The port service consisting of theauthorization
and the assignment of anchorages in the servicearea of the ports of general interest
AM. PADRÓN Y SANTIAGO, L.M. CoIN , A MDRENO-ISAAc JA. GALINDO, A OJISADO,
Panel B3: Efficiency in Navigation Systems
JI. URIARTE-METZABALA On board sailing simulator based on multimedia PC J. JANuSZEWSKI, Terrestrial and satellite radionavigatioo system on the turn of the XX Century
D. ZHOU, H. PAAZU, A study on prediction of possible collision avoidance actions of
target ships in marine encounter
B. PILLICH, AIS and ECDIS- a perfect combination
H.J. MDNTES-COT0, J.M. CUETOS-tGIDo, V. rvRAyo-FERNANDEZ, R. Rojo-DIAz, Integrated System for the Ship's Behaviour Analysis in Intact Loading Condition
(InShipAnalysis)
J.L. LOZANO, J. TERRÓN, Fine Tuning of PID Controllers with Bayesian Networks Aid
for Ship Processes Control
S. AHVENJÄRVI, Safety of an integrated bridge system in fault situations
S. KUWASHIMA, H. HAGIWARA, N. PWASAKA R. SHOJI, Development of a simple voyage
data recorder
J.A. PINKSTER H. HAGWARA, R. Sioji, H. FUKUDA, Onboard Experiments on Weather Vaning Dynamic Positioning System
J.L. LoZANO, C. GIRALDEz, J. CORBERA, X MARTINEZ DE S, Design and assessment
of a control system for high-speed craft: I.M.B.B.O.S. Concept (Interactive Maritime Black Box)
E. GONZAZ-PINO, J. COSTP Ship Control Centre validation criteria and methodology: upgrading ship bridges by retrofitting
MORAWSKI, J. RJMIRSKI, H. GUERDIDJANE, Nonlinear ship autopilot
JA. STOOP, S. HENGST, H. BoONSTRA, Towards a black box for shipping? A SWOT analysis on voyage data recording
ENDo, Shore-based Information-oriented Pilotage System .configuration and
pilotage planning
J.L. CUETO, R. HERNÁNDEZ, V. GoNZÁLEZ, Study of Speech Intelligibility in a Navigation Bridge using a Simple Objective Method
L. MARISCA1 Models and devices currently employed in Indoor Communications at Millimetric Frequencies: Application to the design of Integrated Navigation Systems
A.J. REGUERO-HUERGA, B. MJÑIZ-RUBIERA, JA GARCIA-MAZA, R. FRDIGUER-LÓPEZ,
MA,ALONSO-PIGA, R. ALVAREZ-BUCETAS, R. GARCIANDEZ, A. CAMBLOR-ORfz, The application of the technique of GPS positioning in real time in order to obtain precise coordinates
J. SUOMELA, R. ROUVARI, Shico-the Short Range Navigation, Positioning and Obstacle Avoidance System
M. LARA, T. LÓPEZ-MORATALLA Improving the celestial navigation efficiency
THEME C: HUMAN FACTORS
Panel Cl: Behaviour and Training -Maritime Education
K. CHATTERJEA, The case for on-line adaptive learning through assessments for Advanced Diploma Students in Marine Engineering at the Singapore Polytechnic J.C. RASERO, F. RNIELLA, Simulation as a tool of evaluation: first proposals on the
elaboration of standard rules
C. BERGQUIST, Use of simulators to create stressful situations as a part of CCM courses
R. HELMlNEN Safe-Passage: WWW Based Multimedia Courseware for Basic Safety Training
R. WAWRUCFt Deck Officers' training on the simulator devices
H. IMAZU, D. ZHou, A Method for Grading Marine Encounter Situations in Simulator Training on Ship's Collision Avoidance
R. RODRIGUEZ-MARTOS, The importance of a special training in leadership for captains and officers for a safe navigation and preservation of environment
LARRAURI-PIJOAM E. GJNZALEZ-PINO, J. CARBAJOSA-fvNENDEZ, Strategies for the
choice of crews: individual human factor versus group human factor (from technical selection to the integration of a safety culture)
J.P. \EiGA An exploratory study on the feasibility of introducing new methods in
maritime education and training
D. LEMBURG Simulation: A tool to improve safety at sea2
KOBAYASHI, The Development of MET system using ship-handling simulators
R. BORRAS R. FERREIRO, M. LUACES, J. GARCIA-GALEGO Analysis ofone not senoidal wave with worksheet. Pedagogic application
A. WALCZAK, Implementation of the resolutions of the 78/95 STCW Convention in
Polish Maritime Universities6
J. TERRÓN, M.J. LÓPEZ, C. CORRALES, Modelling, simulation and multimedia techniques ¡n control and steering integrated learning in navigation
J. MJRENO, A CARMONA, C. CORREDOR, L. BEIRA, E. MJNTERO, A. kBA, CREALAB:
A space for collaborative learning and training in electronic technologies
MAALONSO-P1CA, J.A. GARCIA-MAZA, A FDEZ-PÉREZ, J. LLINARES-ALVAREZ GARCIA-FVNDEZ, A. CAMBLOR-ORDIZ, The choice of Nautical Studies. An analysis
of some aspects
P. TOLKACHEV, V. MYKIN, A RNEGIN, Complex simulator for underwater object operators with environmental situation visualization system and electronic chart
Panel C2: Ergonomics and Medicine Aspects
Z. WISNIEWSKI, Evaluation of the injury potential by evacuation with free-fall systems:
focus on the casualties of marine accidents
S.D. H UDOCK, K.V. SIEGFRIED, S.J. \AkJRZELBACHER L.D. REED, Ergonomic
Interventions and Innovations for the Maritime Industries B.E. STENMARK, Human Error ard Cultural Psychology
rvNDIOLA, A DIAZ, F.J. CORREA, E. CUET M. AZOFRA, Human errors in sea
transport of crude oil
LE BOUAR, C. CHAUVIN, Ergonomics in the design process of High Speed Craft bridge
F. VtTZ, H. WDDEL, Ergonomic Design of the Graphical Presentation of AIS
Information
J.A. GARCIA-MAZA, J. LLINARES-ALVAREZ, R. ALVAREZ-BUCETAS, AJ. REGUERO-HUERGA,
R. GARCIA-FVNDEZ, k CAMBLOR-ORDIZ, Rest time among Spanish Bridge Officers
CAMBLOR-OOIz, JA GARCIA-MAZA, P. M\RTINEZ-REAL, M. NOGUEIRA-ROMERO,
MA ALONSO-PiCA, R. GARCIA-tvNDEZ, The analysis of some social circumstances
that influence the human factor
M.L. CANALS, F. COMEZ -MuÑIz, Continuing education on maritime health: new tools for
seafarer's training, an internet refresher course on first-aid and medical care aboard
F. GÓMEz-MJÑIz, Telemedicine around us
E.A. GARCIA-GONZALEZ, The Human Relations in Spanish Ships Environments
Panel C3: Multilingual Crews -Maritime English
R.M.CAMPA-PORTELA B. RODRIGUEZ-COMEZ, 'The Navigator": Spanish/English
-English/Spanish dictionary supported by multimedia
D.C. LEÓN-PÉREZ L. DIVASSOM-CILVETI, Do you speak English? pues suelta el cabo hombre! Designing an English Grammar for Dockers
A. ALEGRIA, E. DALLEY, Applying task-based learning to the Maritime English
Curriculum
AF. LÓPEZ DE \JtRGARA, "Oh no! Grammar again, Sir?" On the teaching and implementation of grammar learning to ESP students
MA ORTS-LLOPIS, Discourse Analysis of Maritime Insurance Policies in English:
The Institute Cargo clauses
A. BOCANEGRA-VALLE, Teaching and Learning English for Maritime Purposes:a
M.D. PEREA, Are On-Line Maritime Dictionaries Safe?
M.D. PEREA, M. NAVARRO, Web-based Instruction for Maritime English Learners MALOSEY-LEÓN, Facing New Changes in the Maritime English Curriculum: Tasks' Design towards the Acquisition of the Standard Marine Communication Phrases E. LópEz-ToRREs, Maritime terminology: an approach to the design of contrastive
teaching materials for monolingual classes
THEME D: MARINE RESOURCES
Panel Dl: Fishing Vessels and Marine Fisheries
F.J. CORnEA, J.J. ACHÚTEGUI, S. fVNDIOLA, M. OFRA, Main causes of the total
losses of fishing vessels
1K. PAP, S. TERDALKAR, F.M. MDRGADO, M.L. FREPRA, Andaman Sea Zooplanktology:
Past experiences, present endeavour and future prospects
M. CASIMPRO-SORIGUER. C. ZABALA, M. MEZ-CAMA, R. CABRERA, JA HERNANDO-CASAL,
Variations in the growth of Sardinia Pilcha rdus (Walbaum, 1792), landed at three ports in the Gulf of Cadiz (ICES IXA)
R. BRAVO, M. CASMIRO-SORIGUER N. \4LLAR, M.C. GOMEZ-CAMA, JA HERNANDO-CASAL,
An approach to studying the selectivity of the Voraz (Page!lus Bogaraveo, Brünnich, 1768) fishing technique used in Tarifa, Spain
J.C. GARCIA-RODRIGUEZ, A GARCIA-MARTIN, A. DlONIS-fvtLlAF' R. AESANCo-GARClA
F. GARClA-GARcIA Measuring of Fishing Ships Hull plating Thickness: Incidence Factors
B. PEREZ-LABAJOS, J.R. SAN CRISTOBAL, B. ANCO, J. TEBAN, F.J. GÓMEZ, Analysis
of Competition in the Fishing sector of Cantabria
G. BOCCADAMO, G. Russo-KRAuss, A. AMARDELLA, Safety codes and working
conditions onboard fishing vessels
M.L.GONzALEZ DE CANALES, J.B. ORTIZ, MA GONZALEZ DEL VALLE, C. AÑUELA,
C. GARRIDO, C. SARASQUETE, Histopathological Alterations in SparusAurata, Crassosfrea
Angulata and Scrobicularia Plana, induced by sublethal concentrations of Lindane
(Y-Hexachlorocyclohexane)
R. GARClMvNDEZ, R.M. FERNANDEZ-Rico, JA GARCIA-MZA, J. LLINARES-ALVAREZ,
ONBOARD EXPERIMENTS ON WEATHER VANING DYNAMIC POSITIONING SYSTEM
J.A. Pinkster*, H. Hagiwara**, R. Shoji and H. Fukuda**
* Delfi University of Technology (The Netherlands)
** Tokyo University of Meitantile Manne (Japan)
Abstract
In this study, a simple dynamic positioning (DP) system called "Weather Vaning DP system" has been developed. This DP system uses only the controllable pitch propeller of the main engine and bow thruster
driven by the PID feedback plus wind feedforward control algorithm to position the reference point on the ship at the specified point on the earth. The system possesses automatic weather-vaning properties, i.e., the headingofthe ship is not controlled by the system but is govemedby envimnmental conditions.
Onboard experiments on the weather vaning DP system were carried out using the training ship Shioji Mani of the Tokyo University of Mercantile Marine. These experiments verified an extremely high performance of the weather vaning DP system. Experiments to pursue a specified point movingon a strait
line and a circle were also carried out, and it was found that the control algorithm of the weather vaning DP
was applicable to automatic tracking.
1. Introduction
The term Dynamic Positioning (DP) means automatic positioning of the Reference Point (RP) on a ship at a Specified Point (SP) on the earth. DP is an indispensable technique for oil drilling in submarine oil fields, laying submarine cables, and sea bottom surveys using underwater robots. In many cases, the conventionalcontrol system of DPemploys
bow thruster (BIT) and stern thruster (SIT), in addition to the main engine-driven controllable pitch propeller to position RP, and simultaneously carries out
heading-keeping. Such a system involves a complex algorithm, and heading-keeping often becomes impossible when there are slmng winds and tidal streams.
In response,a new control system has been developed, which carries out dynamic
positioning only with CPP and BiT in the absence of heading-keeping [1], [2]. This
control system enables dynamic positioning of RP with a small thrust force, because the heading of' a ship naturally coincides with the direction of the wind or the tidal stream. (This control system is called "Weather Vaning DP".)
By carrying out onboard
experiments with the training ship "Shioji Maru" of the Tokyo University ofMercantileMarine, equipped with an RTK-GPS positioning system, the effectiveness of the newly
developed system was assessed.
For sea bottom exploitation using submarine robots and submersible vehicles, it is
necessary that the surface support ship should be capable of accurately tracking the
underwater vehicles. In this specific connection, experiments were also carried out by
moving SP at a low speed aiid having RP automatically track it to assess system
perfomiance.
2. Weather Vaning Dynamic Positioning System
The control system of the Weather VaningDP combines feedbackcontrol relying on data
representing the displacement of RP from SP and feedforward control relying on data representing the external forces acting on the ship's hull. Calculations of displacements of
RP from SP are carried out as shown below.
Here fl3o and lCü, denote the latitude and the longitude of a spcciliedpoint (SP) on the earth, and K, the latituie and the longitude of a reference point (RP) on the
hull, and (15 i and K1, the latitude and the
longitude of the position where the antenna
of onboard RTK-GPS receiver is located,
respectively. If x1 and y denote the longitudinal distance and the transverse distance
between the position of the antenna and RP,respectively, ((15, K) can be obtained from the following formulae. (xj takes a positive value when the antenna position is forward of RP, while yi takes a positive value when the antenna position is on the port side of RP.) (See Fig.l.)
i5(1(XCOSfl+yiSi1fl1)/R1n((15i)
K K1-(x1 inry1 COSfl )/R1,(05i)
where : ship's heading
Rm(ti3 ):radius of meridian of the earTh at latitude
R1( i): rudius of parallel of the earth at latitudet15 i
Longitudinal distance .x and transverse distance y between RP and SP can be obtained from the following formulae. (x assumes a positive value when SP is located
forward of RP, while y assumes a positive value when SP is on the port side of RP.)
LX(KO-
ic)Rp(ti)sinr1 +(ti3o fl3)Rm(tTh)cOsTÌ (3)¿Xy= ('(e 1c)R(13i)cosT1 +(t) )R,(ci 1)sin (4)
The thrust force F of CPP and the thrust force F, of B/T required for Weather
Vaning DP can be obtained by the following formulae.
T
F=x+hV+c.&dtL
(5)where Vx = dAxldt, Vy = dAy/dt
T: time elapsed fiuni commencement of DF R : longitudinal component of external foite R : transverse component of external force
External forces acting on the ship's hull include wind pressure, hydrodynarnic force due totidalstreams (or ocean currents), and drifting force due to
waves. F and R
take positive values if they act on the ship to move her forward, while F and R take positive values if they act on the ship to move her towards the port side. (See Fig.l.)
Coefficients a and a are feedback gains for proportional control, and coefficients l. and
o T
(6)
are feedback gains for differential control, and coefficients c and c are feedback gains
for integralcontrol.
With this control system, the center of effort of external forces such as winds and
tidal streams must coincide with the position of BIT in a state of equilibrium. For
example, we consider a case in which Rl' and SP are coincident, and the center of effort of external force is deviated all from the position of BIT. 1f the external force is divided into a longitudinal component and a transverse component, the longitudinal component
can be set off by the thrust force of CPP, but the transverse component produces a
moment around the center of gravity due to the thrust force of BIT, which is located on the forward side, equal in magnitude and opposite in direction. As a result,the bow turns in the direction in which BIT acts. When the center of effort of external forces is at the
position of BIT, the moment due to transverse component of external force and the moment due to transverse thrust of BIT set off each other, thus RP can be kept in the
position. The center of effort of external forces coincides with the position of B/T when the ship receives winds, tidal streams or ocean currents nearly from dead ahead, hence,
RP can be retained with the bow in the wind, tidal stream or ocean current.
3. Dynamic Positioning Experiments Using Shioji Maru
3.1 Outline of experiments
Dynamic positioniig experiments using Shioji Mani werecarried out in Tateyama Bay in
January, February and March, 2000. The master station of RTK-GPS was located at Banda, near the SW end of Tateyama Bay, and experiments were carried out inwaters
approximately two miles from Banda. The positioning accuracy of RTK-GPS usedwas
5-20 cm CEP.
It was difficult to predict the magnitude of hydrodynarnic force due to tidalstream and drifting force due to waves acting on the Shioji Maru, hence, only the wind pressure
was considered as the external force in the experiment. Wind pressures R and R acting
on the Shioji Mani were calculated using the following formulae:
where 2
O: density of air (0.124 kg.sec Im
VA: apparent wind speed (mlsec)
transverse projected area of the above-water part (79.2m) AL : lateral projected area of the above -water part (246.3 ra2)
C,, : fore and aft wind foree coefficient C,, : lateral wind force coefficient
C, and C were measuredwith a 1.085 m long model of the Shioji Mare in a wind tunnel.
Fig. 2 shows the measurements of C and C.
In these experiments, the effects of PID (Proportional, Integral, Differential)
feedback gains on dynamic positioning
performance were investigated and the
effectiveness of feedforward control
against wiiid pressures and the effects of
the
position of RP upon the control
stability were assessed. At the beginning of the experiments, the ship's
bow was manually kept in the wind
direction and RP was placed at SP, then control
was exercised so that
RPcoincides with SP. Control was continued for 12 minutes, and it was then observed in the
next three minutes that how the Shioji Mare drifted by winds with no control.
During the experiments, the position of the ship was fixed by RTK-GPS at regular intervals of one second, and CPP and BIT were controlled according to formulae (5) and (6) respectively. In these attempts, second-to-second displacements .x and .y of RP from SP were used without filtering them. For speeds V,, and V of RP, apparent wind speed
VA and apparent wind direction from bow (this was used to obtain C,, and Cv), mean
values of past 5 seconds were usedbecause their variations were excessive. Thrust force
F,, of CPP was controlled so that ahead thrust and astern thrust were confined to within four tons and two tons respectively by restricting blade pitch angles. Thrust force
F of
i.0
'w:
; :: z;
i iiUL
if
-Tll iir
ii
I II
II $ i
ils ils tls WAp* 1nd dun f... bow
lg.2 Wind force coeilclonis of Shioji Maru
BIT was also controlled so that both port and starboard thrusts were confined to within 1.8 tons by restricting blade pitch angles.
3.2 Effects of PI D feedback gains on dynamic positioning performance
In the onboard experiments performed in 1998 and 1999, comparatively small PID
feedback gains were used for the weather vaning DP system, i.e. in formulae (5) and (6),
a= = 60kg/rn, I=l000 kg/(m/s), h= 600 kg/(m/s), c= c= 0.2 kg/(ms). After
that, however, simulations using a mathematical model of the ship's motions were carried out and it was found that these PLD gains were too small to obtain a good DP performance for the Shioji Maru. Thus in the experiments in 2000, PID feedback gains were changed
to larger values and the effects of feedback gains on DP performance were investigated.
Fig.3 (a) and Fig.3 (b) show the results of DP experiment with high PD feedback
gains (ax ay = 240 kg/rn, t = 6000 kg/(m/s), b 2100 kg/(m/s), Cx = Cy = 0.5 kg/(m
s)) and DP experiment with low PD feedback gains (a = ay = 60 kglm, 1
= 1000
kg/(rnls), b = 600 kg/(rnls), c., = c,1 = 0.5 kg/(ms)), respectively. In Fig.3, the contours of the hull of Shioji Mani are plotted every 10 seconds for the nine-minute period from the third minute to the 12th minute from the commencement of the experiment. In both experiments, the RP was placed at the bow and the WFF (Wind Feed Forward) control was also applied. Mean wind speeds during the experiments were 12.8 m/s for high PD gains and 13.6 m/s for low PD gains. lt can be seen from Fig.3 that an extremely stable DF was available for high PD gains, whereas longitudinal and transverse movements of
the ship were significant for low PD gains.
Fig.4 shows the natura I drifting motions of the ship plotted every IO seconds under high PD gain control when control was terminated 12 minutes after starting the experiment. The Shioji Mani assumed the position right abeam the wind and drifted
leewards at a speed of approximately 1.5 knots.
Fig.5 (a) shows time series data of displacements .x,.y of RP from SP during the experiment using high PD gains, aiid Fig.5 (b) shows those during the experiment using
low PD gains. lt can be seen from Fig.5 that longitudinal displacements x graduafly
approached to zero when high PD gains were used, but they continue cycling involving
Etg.3 (!)'*PcOO*tt$ JQ):PIoefl pI*. :(*)
dot4òy
31gi PDft,1
Jo « _ Q
1bwi 4aa of
4L.wPD::::::
-Table i summarizes mean values and standard deviations of wind directions
bow, wind speeds, .x; y, F and F during the nine minutes between the third minute and
the 12th minute after starting the experiment. Data in parentheses in the table are standard deviations. The standard deviatioi of displacement .xand .y in the experiment with
high PD gains were 0.6 m and 0.8 n and
they were 4.5 m and 3.2 m in the experiment with low PD gains.
The standarddeviations of required thrust F and Fwith high PD gains were almost thesame as those
with low PD gains. From these experiments, it can be seen that DP system with high I'D gains was more stable than that th low PD gains.
from
I
iaT.,r, ri
The DP experiments with higher PD gains were also carried oui, and it was found that DP system having ax (proportional feedback gain for longitudinal direction) higher
than 500 kg/rn became always unstable, i.e. large oscillating motions in longitudinal direction occurred by the large changes of CPP pitch angle from full ahead (astern) to full astern (ahead). Concerning the integral feedback gain, DP system having high integral gain with low PD gains for the longitudinal direction became unstable, i.e.
longitudinal movements of the ship gradually increased. To determine the optimum
combination of PID feedback gains, comprehensive simulations based on the accurate mathematical model of the ship's motions should be performed.
3.3 Effectiveness of wind feedforward control
In December 1998, onboard experiments to assess the effectiveness of WFF control, i.e. feedforward control against wind pressure, were carried out with low PD feedback gains. From those experiments, it was found that WFF control, which computed wind pressures
acting the ship's hull and created a thrust force to cancel out such wind pressures, was
highly effective in damping transverse hull movements in strong winds [2].
In March 2000, experiments to assess the effectiveness of WFF control with high PD feedback gains ( a, = 360 kg/rn, l
10000 kg/(rn/s), b = 3300 kg/(mls), ç =
= I .0 kg/(ms)) were performed in very strong wind. Fig.6 (a) and Fig.6 (b) show theresults of DP experiment using PID plus WFF control and DP experiment using PID
control alone, respectively. In Fig.6, the contours of ship's hull are plotted every 10
seconds for the nine-minute period from the third minute to the 12th minute from the
commencement of the experiment. In both experiments, the RP was placed at the bow. Mean wind speeds during the experiments were 13.6 ni/s when WFF control was added, and 15.2 m/s when PID control alone was exercised. These wind speeds were in the proximity of the critical limits under which control by BIT was possible. It can be seen
from Fig.6 that a very stable DP was performed when WFF control
was added.Conversely, in the case of PID control alone, longitudinal movements of the shipbecame considerably large.
ri (,pjs
4b-il*1%IWVF 44 ..o C'nt --,*_ O:P( 1'
*1t1iM
*Pfl $a WFP cw*røO.
4'IIe
.a. i*wr*.ø
Fig.7 (a) shows tune series data of displacements .x, .y of RP from SP plotted
during experiment with PID plus WFF control, and Fig.7 (b) shows those during
experiment with P1D control alone. lt is
found from Fig.7
that longitudinaldisplacements x were confined to within ñ I m when WFF control was added, but they immediately increased and started oscillating motions with the amplitude of about 10 ni
when PID control alone was exercised. These longitudinal oscillating motions were caused by the large variations of CPP pitch angle from full ahead (astern) to fullastern
(ahead). Hence it can be said that when using high PD feedback gains in strong winds, WFF control is veiy effective to suppress the longitudinal self-oscillating motions.
3.4 Effects of the position ofRPonboard the ship uponcontrol stability
To assess the effects of the position of RP onboard the ship upon the stability of DP,
experiments were carried out locating RP at L/2 forward of the bow, midship, 1J4 aft of
midship, and the bow. (L is the overall length of the Shioji Mani, 49.93 ni.) BiTof the
coupled with WFF control were applied. The experiments with RP located at L/2
forward of the bow and midship were carried out on January26 in very weak winds (l-2
mis), and those with RP located at L/4 aft of midship and the bow were carried outon
March 8 m moderate winds (5-6 nils).
On January 26, PID feedback gains were set to (ax = ay = 120 kg/rn, h = 3000 kg/(mls), b = 1200 kg/(mls), cx Cy = 0.1 kg/(ms)). On March 8, they were set to (ax =
a = 240 kg/rn, l = 6000 kg/(m/s), h1 = 2100 kg/(nils), c, = c = 0.5 kg/(ms)) for the experiment with RP located at L/4 aft of midship and (a = ay = 300 kg/rn, 1
8000
kg/(rn/s), b = 2700 kg/(mls), cx = c = 0.5 kg/(ms)) for the experiment with RP locatedat the bow.
For the period of nine minutes from the third minute to the 12th minute after
starting the experiments, movements of the Shioji Mani were plotted every 10 seconds and shown in Fig.8 (a) (RP at L/2 forward of the bow), Fig.8 (b) (RP amidships), Fig.8 (c) (RP L/4 aft of the midship), and Fig.8 (d) (RP at the bow), respectively. From Fig.8
(b), it can be seen that when RP was placed amidships, DP was considerably unstable
with large yawing motions. From Fig.8 (c), it can be seen that when RP was placed L/4 aft of the midship, DP was completely impossible with continuous turning motions.
From Figs.8 (a) and (d), it can be seen that when RP was located at L/2 forward of the bow and at the bow, very stable DF could be achieved. The case of DF available
with RP placed forward of the bow as shown in Fig.8 (a) may be utilized for a tanker
whose bow is retained with a specified distance from a single-point mooring buoy and cargo oil is discharged ashore thmugh a pipeline led from the booy.
T
sp, c*krp1s
Generally, Weather Vaning DP controlling the with BIT, control stability degrades as RP
moves from the position of BiT towards
the stem. When a ship turns using B/T, the pivoting point is located slightly aft of
the cenr of gravity of the
ship's hull. When RP is placed in the proximity of the center of gravity, RP does not move to any appreciable extent even if B/T is operated so that RP might come closer to SP. When RPtransverse motions of a ship only
I UÍu. :2N4
o'w L2in#$.
is placed aft of hie pivoting point, RP departs from SP if B/T is operated willi resultant control inability as shown in Fig.8 (e). lt is, therefore, desirable to place RP as close as possible to the proximity of the bow. When RP is placed forward of B/T, RP comes closer to SP at a transverse speed greater than that
of BiT, and hence no control pnblems arise.
4. Automatic Tracking Experiments Using Shioji Mani 4.1 Outline of experiments
The automatic tracking experiments of the Shioji Mani were also carried out in Tateyama Bay during the same period as DP experiments. The positioning system used was the
aforementioned RTK-GPS.
As in the experiments with Weather Vaning DP, the required thrust for CPP was
calculated using formula (5), and that for B/T fcnmula (6). In all experiments, the
position of RP was fixed at the bow and WFF control was applied. Shown here are the
results of the automatic tracking experiments on SP moving along a strait line carried out
on January 28 and February 2, and those on SP moving along a circle carried out on
used n both experiments were (a, = = 120 kg/rn, 1 = 3000 kg/(m!s), 1
= 1200
kg/(mls), Cx = Cy 1.0 kg/(ms)).
Fig.9 (a) and Fig.9 (b) show the positions of SP (marked by the circles) and the ship's hull of the Shioji Mani plottedevery 30 seconds from the start of the experiment on
January 28 and February 2, respectively. To help view the positional relationships
between RP and SP, they are connected with straight lines in the figures. lt may be seen from Fig.9 that the distance between SP and RP slightly increases just after the start of experiment, but RP soon catches up willi SP. In Fig.9 (a), when the ship proceeds true
west, aller tracking has reached a steady state, she makes a large drift retaining her heading direction approximately 50 degrees in the wind. On the other hand, when the
ship steady proceeds true south in Fig.9 (b), the ship's bow points approximately to the
east receiving the beam wiiìds.
4.3 Automatic tracking experiment with SP moving along a circle
t_
..nsst4lIni
4.2 Automatic tracking experiment with SP moving along a strait line
Automatic tracking experiments were carried out with SP moving along a straight line of 31)0 m at
a
speed of
i knotSP was
moved westwards on January 28
4.1 ¿
and southwards on February 2,
and the ship tracked SI' receiving the winds of about 9 nils blowing
Subsequently, automatic tracking
experiment was carried out on March 8
with SP moving along a cin1e clockwise
at a speed of 1 knot
The radius of acircle was 75 m, and the ship tracked SP
receiving the weak winds (about i nils) from NNE. The PID gains used were (a
= a = 240 kg/in, l
= 6000 kg/(mls), l
= 2100 kg/(m/s), c =Cy = 1.0 kg/(ms)). Fig. 10 shows the positions of SP (marked by the circles) and the hull of the
Shioji Mani plotted evety
60 secondsafter starting the
experiment. In thefigure, SP and RP are connected with
straight lines. lt can be seen from Fig.i O that during the period in which SP moved
clockwise on the
circle, RP tracks SP
veiy accurately.
Fig. Il shows time series data Cor
longitudinal distance . x and transverse distance .y between RP and SP. It is
-4
-t
i. thMw...2000... 09 34:4e .o9 504e jsr
I
D1r'24
I ...
.QS.
Fig.1O Sbipi contour plöls
(Trackina cm a circle)
... ...
Thflt iwt
datac 4 Lid Ay
('flickirigon crcIe)
found from Fig. 11 that .x and .y gradually approached to zero until about 660 seconds after
starting the experiment at which an instantaneous error of the ships position of a few
meters occurred because of inaccurate RTK-GPS signals.
5. Conclusions
The control methods for the Weather Vaning DP, which has newly developed, were
explained and the results of dynamic positioning experiments and automatic tracking
experiments carried out with the Shioji Mani were reported above.
The experimentairesults f the Weather Vaning DP demonstratedthe following. (1) The Weather Vaning DP system stabilizes when the ships bow is in the wind. As a
,:
.
result, highly accurate DP is available with a small thrust output of the bow thruster.
High PD gains provided the Shioji Mani with better DP performa ace than low PD gains. However, extremely high PD gains caused the longitudinal self-oscillating motions
of the ship.
Wind Íèedforward wntrol is very effective for damping transverse motions of the
ship in strong winds when low PD gains are used. lt is also effective to suppress the
longitudinal self-oscillating motions in strong winds when high PD gains are used.
As the position of RP on the ship's hull is moved from the bow thruster position
towards the stem, DP becomes unstable. When the position of R? was placed L/4 aft of midship, the DP was completely impossible. Stable DP is also available even if RP is
located forwardof the bow.
In automatic tracking experiments relying upon Weather Vaning DP control
methods, a specified point moving on a strait line and a circle could be accurately tracked, which verified that the control algorithm of the Weather Vaning DP was applicable to automatic tracking. Throughout the experiments, RTK-GPS was fully capable of
supplying positional information at the highaccuracyneededfor dynamic positioning and
automatic tracking.
To upgrade the accuracy of the Weather Vaning DP system in the future, it is
planned to carry out comprehensive simulations based on the accurate mathematical model of the ship's motions to determine optimum combination of the ND feedback
gains. In addition, drifting forces of waves not considered in these experiments will be calculated, and by adding it to the wind pressure, new feedforward control method will be developed. lt is also planned for automatic tracking to determine optimum feedback gains from simulations, and to carry out a variety of tracking experiments with specified
points moving along diverse routes at various speeds.
Bibliography
Pinkster, J.A. 1986, Dynamic Positioning of Large Tanker at Sea. Proceedings of the
Offshore Technology Conference, Houston, 459-476.
Pinkster, J.A., Hagiwara, H., Shoji, R. and Fukuda, H. 1999. A Study on Weather
Vol.101, 83-93.
Acknowledgements
The authors wish to express their gratitude to Mr. Joost Verspuy, who was a student of the Faculty of Design, Engineering and Production, Delft University of Technology and stayed at the Tokyo University of Mercantile Marine from January to March in 2000, for his cooperation in developing the simulation programs to evaluate the performance of weather vaning dynamic positioning system. The authors are deeply indebted to Dr. Kohei Ohtsu, Professor of the Tokyo University of Mercantile Marine, Capt. Ichiro flatta, Master and Mr. Noriki I{irose, Chief Engineer of the Shioji Maru, a training ship of the Tokyo University of Mercantile Marine, and the crew members of the Shioji Maru for their valuable
