m
THE
NITELLIGÉNT
SHIP:
P1994-15
10 - 11 March 1994
Mount Royal Hotel
16th International Marine Propulsion Conference
The Intelligent Ship:A Commercial Reality? The Mount Royal Hotel, London -10 & 11 March 1994 Contents
Conference agenda ii
Outline for an InteUigent Ship 1
Dr. Hans Jacob Gâîjéns, Howaldtswerke-Deutsche Werft
What dq ship operators want? - Rudi Hansen, Nedlloyd Unes 11 Détailed prediction óf engine-ship interaction: The basis for Intelligent Engine control 17
Prof. Nicholas Kyrtatos, National Technical University öf Athens
Towards the Intelligent Engine - Kaspar Aeberli, New Sulzer Diesel 35
Intelligent conditon monitoring of ship machinery systems 49
Prof. Hans Klein Woud, Delft Univereity of Techhtridgy
Engine room computerization - Ingmar Ahlqvist, Wärteilä Diesel International 61
Development towards the Intelligent Engine 77
Peter Sunn Pederson, Man B & W Diesel
The benefits of intelligence for cargo control r Bruno Arndt, Technolog 89 The fully integrated bridge control system - Tore Holth, NORCONTROL Automation 99
Communicating with the Intelligent Ship - Scott Knox, Inmarsat 105
Certification and manning for the 21st Century 115
Captain Jack Waters, Shell Intemational dipping
Clutch control for reverse reduction gears 125
Dr. Andresfê Steinbach, Lohmann & Sjplterfoht
The applfcatian of ahborrie HUMS technology to narine engineering systems 129
Dr Andy Nonns, Kelvin Hughes Ltd
What are the benefits óf integrated ship control? 137
Bgil Haaland. NORCONTROL Automation
Electronic Charting: What are the developments? 151
Dr Peter Smeaton, Liverpool John Moores University
Automation sysems för vessels with minimum crew 165
DT; Günter Ackermann, STN Systemtechnik Nord The Motor Ship
Quiadrant House The Quadrant Sutton
Surrey SM2 5AS Tel. +44 81 652 8183 UK Fax.+44 81652 8180
The Motor Ship 16th International Marine Propulsion Conference
The Intelligent Ship:A CommerGial Reality? Agenda ^Thursday, lOth March
8.30 - 9.15 Registration and Coffée
9.15 Opening address from Motor Ship Speaker: Paul Doughty 9.25 Chairman's Introduction
Chairman: Prof. Consitantin Gallin iDeift University of Technology
09.30 Outline for an Intelligent Ship
Speaker: Dr. HansJacok) Gâljëns Howaldtswerke-Deutsche Werft AG 10.05 What do ship operators want?
Speatœr: Mr. Rudi Hansen Nedlloyd Lines
10^0 Detailed prediction of engine-ship interaction: The basis for
Ihteitigeni Engine control
Speaker: Prof, Nicholas Kyrtatos Schooi of Marine Engineering
National Technical University of Athens 11.00 Morning Coffee
11.25 Towards the Intelligent Engine
Speaker: Mr. Kaspar Aeberli New Sujzer Diesel Ltd
11.55 Intelligent condition monitoring of ship machinery systems Speaker: PhDf. Hans KfeinWoud
Delft University of Technotogy 12.30 Lunch
1 4 ^ Erigine room computerizaHpn
Speaker: Mr Ingmar Ahlqvist Wärtsilä Diesel International Ltd 14.55 Development towards the Intelligent Engine
Speaker: Mr Peter Sunn Pederson Man B & W Diesel A/S
15.25 Tea/coffèe
15.55 The bene^ts of intelligerKe for cargo control Speaker: Mr. Brurio Arndt Technolog GmbH
16.30 Session Ends
The Motor Ship 16th Intemational Marine Propulsion Conférence
The Intelligent ShipiA Commercial Reality? Agenda - Frictay, 11th March
8.30 - 9.00 Coffee
9.00 The fully integrated bridge control system Speaker: Mr. Tore Holth NORCONTROL Automation a s . 9.30 Communicating with the Intelligent Ship
Speaker: Mr. Scott Knox Inmars^
10,05 Cer^ficaHon anci rrmming forthe21st Century Speaker: Captainjack Waters Shell Intematiorial Shipping Ltd 10.35 MomingCoffee
11.00 Panel Session
PanelHsts: ir Teus van Beek, Lips B.V.
Dr. Andreas Steinbach, Lohmann & Stolterfoht John H. Phipps, Caterpillar Inc.
11.45 The application of airbome HUMS technology to marine
engi-neering systems
Speaker Dr. Andy Norris Kelvin Hughes Ltd
12.20 Lunch
14.15 What are the bené^ of integrated ship control? Spraken Mn Elgnl Haaland
NORCONTROL Automation a.s.
14.45 Bectronic Charting: What are the developments? Speaker: Dr. Peter Smeaton
School oi Engineering & technology Management Liverpool John Moores Uniyers^
15.15 Tea/ coffee
15.45 Autpmapon systems for vessels with minirnum crew Speaker: Dr Günter Ackermann
STN Systemtechnik Nord 16.15 Cfiaimjan's dosing remarks 16.20 Conference Bids
NHÜSIÏP
Chairman's Introduction Prof. Dr Ing. C. Gaïlin
Head of The Faculty of Engineering and Marine Technology
Delft University
Constantin Gallin graduated in Naval Architecture and Marine Engineering at the Technical University of Bukarest, Rumania, in 1950.
The following six years he worked at the "Ipronav" (Institute for Ship Design) in Bukarest. From 1956 to 1957 he was employed by the British Ship Research Association in London and subsequently he went to Hamburg, where he joined tirç shipyard Blohm & Voss AG. There he became the Head of the Research Department.
Professor Gallin is Chairman of the Euro-pean Association of Universities
WEGEMT and also adviser to leading manufacturers of marine propulsion plants as well as shipowners worldv/ide. In 1982 1987.1988 and 1992 he vm chairman ofthe Intemational Marine Propulsion Conferences in London. Professor Gallin is ä fellow of the R.LN.A., London, and member of the S.TG., Hamburg, of the S,N.AM.E., New
York, of A.TM.A., Paris, of the K.I.V,I.,
The Hague and of the A.R.F.. St P^ersburg.
In 1987 the honorary title of
"Konrespondent Mitglied" was awarded tb prof. Gallin by the Verein Deutscher Ingenieure (VDf), Dussetdorf.
mfröSSliP
Outline for aïi Intelligent Ship Dr-lng. H. J . Gätjens
Manager, "Machinery, Electronics and Development"
Howaldtswerke-Deutsche Werft A G
Dr-lng. H. J . Gätjens is rnanager of the project department "rnachinery, electror>-ics and developrnent" for rrierchant shipbuilding at Hoy/atdtswerke-Deutsche Werft AG. After being marine engrrteer on several ships of the Hamburg-Süd shipping cprnpany. he studied marine engineering and left as Doctcr of Science (Engineerir^). 1990 he joined HDW as project manager for research and devel-opment, since 1992 he is in the above mentioned position.
OUTLINE FOR AN INTELLIGENT SHIP
1. INTRODUCTION
In the last years studies were published v^ich promised the shipping and maritime industry a fcMight future in the late 90's and at the beginning of the next century. On the other hand the present economic situation is rather gksomy.
Because of the last spectacular ship disasters (Exxon Valdez, Scandinavian Star, Braer, Sherbo) and their coverage in the mass rhedia the public is more sensitive to environ-mental pollution. Higher demands on shipbuilders and operatcrs regarding safety, quality assurance and environmental protection will be required by the authorities. With this background the maritime industry has to develop new measures to increase the safety and ecorramy of the fleet whereby the whole lifetime of the ship from the first specification to the scrapping has to be taken into consideration.
The "Intelligent Ship", which does npt autpmatically mean that she is equipped with a large amount of sensors, computers and software, can be one of the solutions. To make it a commercial reality again a large amount of intelligence is necessary.
2. DEFINITIONS
To describe a subject as highly complex as the "Intelligent Ship" it is useful to make some basic definitions.
Definition of Intelligence:
• power of learning, understanding and reasoning • mental ability
Definition of Ship:
• large vessel carrying people or goods by sea
Intelligence in its basic d^inition is always related to living beings, rriostly humans. By this definition a ship cannot be intelligent.
However, al) the people involved in buitdng and operating ships transfer their more or less intelligent solutions to the product. So the "intelligence" of a ship can be measured by the amount of realised good ideas regarding technical hardware and organisation. Using this definition there is no ship without intelligence, intelligence is necessary even
to build and operate ä log caiîoë. It is necessary to subdivide the products into ships with a
• low • average • high
degree of intelligence. The following descriptions concentrate on ships with a high degree of intelligence.
3. ECONOMIC AND TECHNICAL CONDITIONS
The technical deyelopmerTt of shipbuilding and ship operation has led to an increase in reliability and econprny. The highest degree of intelljgenpe is reached in passenger ships, ferries, large container ships, LNG Caniers and in chemical tankers.
To malœ an Intelligent Ship reality the potential for increasing economy and safety has to be taken into account.
Economy
The greatest advances have t^en made in reducing fuel costs. The specific fuel con-sumption has been decreased by 50% in the last 20 years (Fig. 1 ). Main and auxiliary diesel engines are able to bum fuels of the lowest quality The fuel prices are d m h to the level of 1975. At present owners eto not accept already developed measures like the exhaust gas tuit)ine as booster or genset, because of very high investmait costs.
UocfiJIkWni 220 -210 J _ 200 190 160 J _ tro _ _ 160 X 150 140 USSR M 0 0 M H l n * 0 l M * I O U HFDMnyFtMOiaaOIOSt 1S7B 1900 isas 1880
Development of the spec. Fuel Oil CansumpUon for Diesel Engines Pe> 10.000 kW
nunbsr
NtoMd min. M W iwiMr
•towvd nn. CW nunijtf inDmnorti
1960 1965 1970 1975 1980 1966 1990 19BS
DevelQpmmt of the Crew Number
for German Ships > 10.000 GT Rg.2
Due to the high personnel costs in the developed countries, the ships syistems are developed to such an extent that they can be safely operated by 10 crew members. The limits are given by the authorities (Fig. 2). At present shipping faces a Significant lack of qualified naval officers and this situation wilt becorne even worse in the near future due tp the increasing rhean age of the technical and nautical officers.
Maintenance costs and costs for insurance could pot be reduced, to the contrary they increased over the last years.
Safety
The number of ships lost has deaeased from about 350 in 1960 to 200 in 1990 How-ever, the ageing of the fieet will turn this trend to higher leases per year The latest ship disasters caused the whole industry to be viewed by the public iri a glooniy light. Statistics of marine casualties have been published by several authorities. Comparing the statistics of various countries one will find differences in the percentage share of incidents and causes. However, some general statements can be made.
Regarding the incidents two kinds of damage dominate: • collisions, grounding 50... 75 %
• machinery damage, fire 1 0... 20 %
The causes can also be subdivided into two main groups human error and wrong
operational procedures technical malfunction
50... 80 % 10... 20 %
The infiuence of the ships âge on darhages is remari<able.
The darhage rate for tankers over 15 years old is about two times higher than on ships less than I 0 years of age (IMO statistics).
Environmental aspects
Seabome transport is the most environrnentally friendly way to transport goods and people. One new requirement will be to reduce exhaust gas ernissions by 30 %. Some nations and ports created new rules for exhaust gas emissions, intemational rules are desirable. Sludge oil should generally be burnt ashpre.
4. DEMANDS AND DEVELOPMENTS ON INTELLIGENT SHIPS
The above mentioned conditions will lead to positive new alterations for the ship's future operation, fbr example:
further deveiopment pf automation piants higher reliability with smaller crew
compliance vvith stricter rules
further improvement pf economy and security
To reach these aims it is necessary tp distinguish between "Operafion" and
"Mainte-OPERAHON REQUUFUÏREW OPERATION SAFETY ECONOMY MIMINISTRATION MAINTENANCE
EMERQENCY- ' CARQOCARE SHIPS with high
REPAIRS MAINTENANT ROUTINE- ' MOORING MAINTENANCE ' LOGISTICS MAINTENANCE ' LOGISTICS OMSERVATION ' -PROVISIONS MAKSISSERVrCE AOOITIONAL-CREW REMnKWEW REPAin-WORKS OASS-WORKS Condition oritRlcd MAINTBUUICE
HDW SHOPSY CREW ORGANISATION Fig. 3
nance", as yrall as to use modem information technology. This leads to the "naval officer of the future" who has a changed field of tasks with his major responsibilities lying in the operation of the ship, the ship's security and her economical operation. In addition to these main tasks he has to be prepared to take care of loading/unloading, catering, mooring, small mairtónance jobs etc. (Fig. 3).
On the one hand these new and
additional responsibilities have to lead to new requirements in crew educa-tion; on the other hand the crew must be provided with the necessary tech-nical equipment.
Based on the very supcessful German "Ship ofthe Future" project(SdZ) Howaldtswerke-Deutsche Werft (HDW) constantly increased the intelligence of their new ships. For the R&D project "Ship Operation Systems" (SHOPSY),
HO\N again is responsible forthe
tech-nical m a n a g e m ^ . In SHOPSY 21 com-panies and institutes are working to-gether on six development topics (Fig. 4).
T h e target of the development in ^ O P S Y is to provide the operators with systems which help them to keep or in-crease the present standard regarding reliability and economy, even when saii-ing with a less experienced crew.
•T 1 BT I EIS eT4 {TS tt e DORA NOPSY SHOPSIM KMA
eanpulw A I M SMtaton SoppM md MMmMton SyMMn tar SMp Cpmmam'mta P^Mt Muna O M M I Slt^ DMiimwiMtton SyMMn
StaoMor lar T M i g R Ù I
AOssnoad ttimdllliui HmNadni for ^—1| Tri nil
l f i |
HDW
SHOPSY PROJECT Rg. 4
The most important aspects of the S H O P S Y developments are: knowledge-based decision support systems
general data documentation
further development of nautical systems energy management systems
cpndition orientated maintenance
In addition tp several R&D projects there are some developments in the solidhardware (hull, machinery) which are also increase the intelligence of the ship.
Not all the new ideas, developments and products which make a ship intelligent can be mentioned in this brief outline. But the examples show that intelligent solutions are necessary and can be a commercial reality.
Hull
t h e economy of a ship is characterised by high transport performance in relation to size and speed of the ship and low capital and operational costs. The intelligent ship with a small crew has some influence on the specification of the hull.
There is no time fbr conservation woric anymore. Coafings and coating methods have to be developed so that conservation work may be done only during the docking peri-ods.
The warping and mooring equipment has to be operated by one person only or by remote control.
The few people on board cannot take care of cargo related work like supervising lash-ing and securlash-ing containers.
An example that intelligent solutions sometimes take a long time to realise is the open top container ship (Fig. 5), First ideas were created in the 70's, the first realisations started in the 90's.
The benefits of this solution are tower costs for loading and discharging and higher safety agajnst losing containers in heavy weather. In addition to these benefits HDW installed light rain shelters, a deckhouse v/ith a small wind area and a windbreaking front hood. All tiiese measures led to lower wind resistence and lower fuel consump-tion.
Machinery
The intelligent ship needs a reliable propulsion plant
All measures should be taken to Increase operating times between overhauls and tb realise a condition oriented maintenance.
Diagnostic expert systems and maintenance control programmes are solutims to in-crease reliability. They are necessary when owners deckJe to operate the ships with an inexperienced crew.
Power management systems for the electric power supply and black out avoidance programmes should be installed.
Regarding the machinery systems, all subsuppliers should make efforts to standardise and modularise the aggregate. Thiis l ^ d s to cost reduction for yards and owners and less work for the crew.
The fuel system is one óf the most important systems for the reliability and economy of the ship. A failure in this system always has an infiuence on the main propulsion plant, some statistics say that at least about 40- 50% of all malfunctions of the main propul-sion plant hâve their origin in the fuel system.
A simple solution would be to change from HFO to MDO, unfortunately this solution is very expensive. As long as burning HFÔ without exhaust gas treatment is not
forblö-den woridwide this is no economic reality
One of the features realised in the Shopsy Prpject is an expert system for the fuel sys-tem. The object orientated way for modelling the parts of this systern allows the de-scription of several fuel circuits without a lairge lot of extra work.
Automation
as the one rrran bridge operation by day ahd night are state of the art.
The amount of sensors shpuld not be increased for new automation systems, because the MBF of the sensors is sometimes lower than the MBF of the parts to be controlled by the sensors.
An intelligent combination of the available information leads to more safety rather than too much information.
The standardisation of data modelling and data transfer are one of the most important requirements in the future. It is the basis of a consistent information model. Develop-ment projects like Maritime Information Technplogy Stsuridard (MITS) and SHOPSY are the first steps in thé right direction. However, under the pressure of cost reduction and global sourcing European solutions and s t ^ d a r d s are not sufFicient.
The man/machine interface also has to be standardised. The operator of a ship cannot be burdened with different user menues, descriptions and displays for each application. There are some ships with 8 or more different ai:^Iications, each with its om monitor and display installed on the bridge. How can one man use all this equipment in a rational way during his watch?
An example for an intelligent solution is shown in Fig. 6. All aii^iications can be used from one woricstjation. The basic
information fpr operating the ship and the alarm indications are pennanently shown on the dis-play H u l ^ Knowledge Base ARPA ' rr—: r ARPA ' rr—: r
m
EÇPIS Data Base Software Anticolltsion Manoeuvre SimulationL"! Opereüpr Track Control
A
H D W
NOPSY
ANTÎ-CQUJS10N SYSTEM Flg. 7
Nautical systems
ÄS mentioned before most inci-dents involving ships are colli-sions and groundings. New methods to increase the safety of the ships have to be developed. The electronic sea chart v^th "inteliigenf objects is a basis for further developments to increase the safety of the ships by means of
• overlaying radar information • manoeuvre simulation and
track prediction
• knowledge based collision avoidance programmes. The software for this measure was developed in the
NOPSY-Project (Fig. 7).
In addition to this, planning systems which increase the economy such as route optimisation and weather routing programmes should be installed on an Intelligent Ship,
5. BENEFITS OF T H E INTELLIGENCE
An Intelligent Ship can reduce the pperational cpsts and safety and reliability can be increased.
No matter whether owners decide tp operate the ships with a minimal crew pf highly qualified people or to sail with a large number of less qualified qrew and some experi-enced ofTicers, the intelligent systems can reduce the workload.
Safety and economy of ship operation will decrease, if the vrarklpad of the remaining crew is not reduced:
if "natural" intelligence is not available or too expensive art^icial intelligence can be utilised. The most important thing is that these expert systems be easy to handle even by not.highly qualified people.
The maintenarKie costs can be reduced by means of diagnostic and maintenance plan-ning systems. The early identification of malfunctions arïd decision support by expert systems can prevent exberisive and costly damage. An intelligent condition orientated maintenance programme reduces costs for spare parts.
Insurance companies should think about a more intelli^nt classification of ships and ship operators. If owners invest more money in the safety of the ship and in the educa-tion of the crew there should be financial benefits.
In the developed countries jobs on board ships are not considered very attractive. The Intelligent Ship combined with a modem organisation can change the irhage of an "old-fashioned" industry.
6. CONCLUSION AND OUTLOOK
In the maritime industry the KISS-strategî/ (Keep it Simple and Stupid) is sorhetimes taken irito consideration as the best way for present and future ship operation.
One should bear in mind that keeping things as they are is alvräys a step back. On the other hand good and simple solutions require brilliant ideas and intelligence. The
whale industry should make efforts to make the ships simple and intelligent and of
course efficient and economic.
The ships are only one part of the transport chain. There is a potential for optimising the whole logistics from producer tb customer.
In the future the shipovmers, freight agencies, shipyards and subsuppliers, terminal operators and shore based transport companies have to find intelligent solutims for the entire transport system.
MölüliSIP
What do ship operators want? lr.R.K.Hansen, MSc, CEng, FIMarE. Head, Fleet Newbuilding Department
Nedlloyd Lines
After graduating at the Delft University of Technology in Intemal Combustion En-gines, he has been in charge the development and testing of marine Die-sel engines. He also worked as Techni-cal Manager ofthe Ethiopian National Shipping Company
Since 1975 he is head of the fleet newbuilding department of Nedlloyd Lines and his special concem goes to the machinery systems and the man ship interfaces.
WHAT DO SHIP OPERATORS WANT?
1. \Nhai dp ship operators want?
2. Do we want intelligence on board of ships? 3. Why do WB need Ship Intelligence? 4. What is Ship Intelligence?
5. Present state of art,
6. Further developments, why and how? 7. Psychological aspects.
8. Conclusions, if any
WHAT DO SHIP OPERATORS WANT?
Ship operators want ships with a long life at lowest life time cost.
• Long life does not OTiy mean good quality, but also being advanced in technical and operational abilities, in order to avoid early out-dating.
• Lowest cost means fow initial cost, augmented with daily operating costs, such as fuel, manning, cargo handling and maintenance.
DO WE WANT INTELUGENCE ON BOARD OF SHIPS? Where does "intelligertóe" fit into the low cost requirement?
Ship intelligence can reduce neariy all operating cc^ts, like - car^o handling by a load-ing computer
• maintenance by condition contnal • energy by power management • etc.
whereas the initial costs are generally low. WHY DO WE NEED SHIP INTELLIGENCE?
For mentioned reasons Ship Intelligence, SI, has already entered into ship's systems many years ago.
The question whether we need SI is npt a matter of a simple yes or no, but a more shaded matter of "to vvhat extent".
WH AT IS SHIP INTELLIGENCE?
What do we mean with intelligence on board of a vessel, which I would prefer tp de-scribe in short by "Ship Intelligence" rather then by an "Intelligent Ship".
upon the introduction of the urirharined engine room a basic level of intelligence was introduced, comprising
• automation of ancillary systems, suitable for rather siteady operation of the propul-sion and electric power Units
• remote confrol of the main engine, suitable suitable for officers without a technical training
• loc^l instruments
• safety and protection systems
• remote annunciating and waming system.
In the wheel house the intelligence was limited to an autpmatic
steering gear and some special instruments, like radars and position measuring equip-ment.
Wë could define SI tp be all instrumentatiPn, remote controls, mpnitortng without with calculation functjorrs, forms of présentation and display y\^ich are exceeding the bask: requiremwits of an unrnanned engine rppm of about 30 years ago.
I realize that this definition is quite arbitrary, and one cpuld take any other mile stone as a starting point for the devetopment of SI.
WHAT IS THE PRESENT STATE OF ART?
Contrary to the frequentiy heard suggestion that manning reduction woukd be tiie main purpose, SI has been developed for all kind of reasons and in many different, ways. Also the initiators of SI ans of different origin, like:
• the makers, witii the object to improve the perfonnance or to safeguard their product.
examples: - auto clean confrol of centrifugal separators - auto pitch ccmtrol for C P propellers
- LED'S on relay coils
• tiie classification and regulatory bodies, generally with the sole object to protect and safeguard.
examples: - loading computer
- exhaust gas deviation alarm
• the operators, simply in order to reduce life time costs, by:
- improving the quality of decision rrraking through highly qualified information - reducing human errors by ergonomie, simple and fool proof controls
- reducing maintenance by optimizing operatipnaj conditions for machineries - fuel saving, for example by voyage planning, power management etc. - saving operatipnaj man hours by dedicated automatical.
Modem techniques have made it possible to reac^ the present level of inteiiigence. Most of such inrtelligence can be applied without adding much hardware compared with 30 years ago, apart from the computer systems.
Presently ti^ biggest part the Ship Intelligence is initiated by the ship operators. This will be the main reason that there is not much stmcture in the inteiiigence systems
or even in the components.
FURTHER DEVELOPMENTS, WHY AND HOW? Do we need more Ship Intelligence?
All arguments for the present SI are also applicable for further development bf S l The general trend in future ship installations shall be a combination of more simple hardware and more intelligent software.
There are still many fields where intelligerrce is very much needed either to give the crew a better knowledge of the situation or tp protect the installation from maltreatment, bverioading, etc.
I am very anxious to hear the proposals from the engine makers during this conference. Especially these essential and complicated Diesel engines are lacking any sophistical tion in the instrumentation and sorrre very important instiximents are missing completely. To make à judgment of the running conditipn it is inevitable tp measure:
• Cylinder pressure diagrams, which is nowadays possible in a intelligent way.
• Some well known makers of big auxiliary engines do not even measure compression pressures during shop testing.
• Fuel injection pressure diagrams.
• All parameters around turbo chargers and air coolers.
• overioad condition in an adequate and reliable way. Fuel rack position or diarge air to fuel ratio are primitive and not suitable for the purpose.
So far all these matters are left to the discretion of tiie operators whereas in my opinion the makers Should fâke care.
For the "air factory" of the highly supercharged engines an adequate pondition monitpr-ing system shall be developed and supplied as a standard.
Another example of very needed SI, is a good and reliable voyage planning system. Some attempts in this direction are made at the moment, but stij) much wori^ has to be done.
PSYCHOLOGICAL A S P E C T S .
Any form of intelligence in ship's systems have a direct impact on the relation betwisen man and ship.
The psychological effects of additional intelligence is not to be neglected. The accept-ance of SI is not as a matter of fact and needs careful infrodudion and guidaccept-ance to the crew.
In many cases it is the option of the crew to make use of the Sl.
Witii a negative attitijde of the officers towards SI, it will be a non profitable investment or may even work contre productive.
Consequently SI shall not become a revolutionary development in order tp keep pace with the social and educational changes of the
mannJnO-CONCLUSION.
Ship Intelligence is a matter of fact and further development is inevitable.
However the approach shall move in the direction ofthe makers. The complex nature of high perfomnarm engines and machirtes is becoming inaccessible for the operators and "intelligence" shall be added by the makers as an integral part of tiieir deliveries.
Détailed Prediction of engine-ship interaction; The basis for Intelligent Engine Control
Nichpias p. Kyrtatos Associate Professor of Marine
Engineering
Natipnal Technical University of Athens
Nicholas P. Kyrtatos was bom in Athens, Greece in 1954.
He obtained a B.Sc. (Hons) Degree in Marine Engineering Irm the University of Newcastle Upon Tyne in 1975, a D.I.C. in Medianicai Engineering and a Ph.D. degree in Thermal Power from the Impe-rial College of Science aruj Technology ofthe University of London in 1979. He was Visiting Professor in Mechanical Engineering at Mc Gill Univerisity, Mon-treal, Canada in 1980-1982.
He is Associate Professor of Marine Engineering at the National Technical University of Athens.
DETAILED PREDICTION OF ENGINE-SHIP INTERACTION THE BASIS FOR INTELLIGENT ENGINE CONTROL
ABSTRACT
A model for the detailed prediction of the transient response of the engine-ship system has been devetqsed.
This model includes a comprehensive engine perfonnance prediction pmi as well as models for the hull and propeller hydrodynamics and ship kinetics. The engine model alloy^s regulation öf parameters affecting engine
perfonnance so that it may also be used for simulating the neoct-generatipn of marine prc^ulsion plants, which will include elecfronically controlled engine events.
Such models may be incorporated witiiin SKjvanced propulsion plant control systems to provide reference predictions for adapting and optimising the engine regulation scherhes.
Results using the model to simulate the behavtour of large direct-drivia engines during ship manoeuvres are p r e s ^ t e d and discussed.
INTRODUCTION
In the past thirty years, tiie marine diesel ertgine has become the rnost
efficient powerplarit for ships, through continuous development and technical innovations.
In large two-stroke diesel engines the increases in stroke/bore ratio and BMEP, the adpptipn of constant pressure turbocharging and unifiow
scavenging, have characterised the period from the mid-seventies to d ^ e . It would appear that the mid-nineties will ino-easingly vt^tness advances in microprocessor^ased regulation of engine elements (such as fuel injector pump mechanisms or exhaust valve drives). In such arrangements, the various engine actuators will no longer be constrained by a mechanical linkage to the engine to ensure a secure and repeatable fijnction.
It can be anticipated that such systems will eventually be used on-board ships, also in conjunction with integrated ship management and control networks.
The dependability of such "sail-by-wire" arrangements has been already proven in systems of related functipnality in the aerospace industry. For example the digital flight management systems used in all modem warplanes and increasingly in commerciat a i r c r ^ are required by specification to have a
probability of catastrophic failure of < 10"9/hr over a 10 hour period. This means that such a failure would not be expected to happen in the lifetime of the fleet [1].
By using such systems, the next-generation marine "intelligent" propulsion engines, will have a much wider flexibility in adjustment and adaptation. The temi "intelligent engines" has come to characterise propulsion and auxiliary m a c h i n ^ , which in the course of tiieir use can be automatically adapted to changing operating conditions, so that they p ^ o r m their tasks in an optimum way. [2]
Thus, an intelligent engine would scrutinize its own condition, monitoring the h ^ l t h ofthe powerplant and would also adjust its parameters for optimum performance in a selected running mode, taking into account engine optimising functions and management features, such as maintenance scheduling and spare parts planning.
This requires advanced performance monitoring and perfonnance evaluation systems, the former to ensure that the engine fulfils its function properiy, the latter to verify that this function is performed in an optimum way.
Some comparison must then be executed so that the system can infer the "condition" of the machinery from the input data, and through embedded rules perform appropriate adjustments to the engine.
(It must be noted that since no learning abilities -a p o w ^ u l index of intelligence- are perceived for tiiis generation óf engine management systems, then the ratiier aspiring tenn "intelligent engine" can be accepted simply as a commercialiy attractive eponymy.)
Witii microprocessor controlled components and paramtóers, tiie following can be adjusted without extensive mechanical complexity:
• Valves timing
rate of opening/closing
(indirect) control of compression ratio inlet swirl through valve control (4-«troke) • Fuel pumps/injectors
timing
rate of injection
pattem (selective injection) • Cooling
engine components charge air
• Cylinder lubrication
• Turbocharger, power/rpm (hence boost)
Already large two-stoke productton marine diesel engines are fitted with load-dependent variable injection timing systems, which, for e^cample, can be used to sustain the MCR maximum c y l i n d ^ pressure at lower engine loads, to Improve specific fUel consumption. Also, various cpnfigurations of
hydraulically activated variable exhaust valve timing mechanisms have been used experimentally in such large engines.
A conventional propulsion system has inherently a very substantial degree of self-regutatton regarding speed control. Therefore, in steady state
conditions, the ability of the engine to adapt to changing parameters has only limited Use.
It is the controlling and optimising of tiie behaviour during transient
phenomena where improved regulation of the machinery becomes important. However, the regulation ofthe machinery even in conventional terms (e.g. speed or toad regulation) cannot be considered independently from the ^ e c t s and responses of the propulsion system and the behavtour of the
propeller, the rudder, the ships hull resistance and the kinematics of the whole ship.
With the ability of the engine events to be regulated independentiy, through the proposed microprocessor cbntrolJed actuators, a more exact optimisation procedure is possible, but the added degrees of fi^edom make tiie problem far more complex. Therefore the effects of engine-ship interaction have to be scrutinised more closely.
In such a case, the detailed mathematical modelling of the whole engine-ship system and the simulation of its behaviour on a computer can prove quite useful.
Such simulation models can be used for studies to predict the performance and define the limits of operation bf the system for a very wide range of boundary conditions, thus providing baseline information, to be used in defining optimum adjustment procedures and guidelines.
Due to advances in computer power, such models can be used not önty for off-line studies, but also, in the very near future, tiiey could be used within propulsion engine management installations.
In this latter case, a simulation model can be provided with proper input to generate reference values for particular parameters, which can be further used by the control system to adjust the propulsion machinery according to prescribed directives.
Shown in Fig.1 is a schematic of an advanced ship engine managertient system vyhich integrates modules for monitoring, control, diagnosis of malfunctions and scheduling of maintenance. It also includes a propulsion system simulation module which could provide reference values for various engine operating modes to be used by the confrol system for comparison arKi optimum adjustment of tiie engine parameters according to predetennined guidelines.
Thus, the engine-ship interaction simulation models may become crucial in the optimum confrol of the next-generatton propulsion engines.
ENGINE-SHIP INTERACTION SIMULATION MODEL
The overall engine-ship interactton model d^cribed here is called MIMESIS (Mathematical Model for Engine-Ship Interaction Simulation).
The engine performance prediction mpdel is called MOTHER (MOtor THERmodynamics) and is a computer program capabie of simulating the perfbrmance of a wide variety of diesel engines in steady state and transient operation.
When this comprehensive and quite accurate engine perfomiance prediction model was extended to cover transient response phenomena, it was soon realised that the coupling and interactton of the propulsion machinery with the propeller/hull combination would be of high importance, in order to obtain the instantaneous load on tiie engine.
Hence, separate modules containing representatiorïs of tiie propeller operation characteristics in the four quadrants, a model of the riKlda* response, a model of the hull resistance as well as a representation of the coupled surge -sway- yaw equations of motion fpr ship manoeuvres were developed.
The propulsion plant model is shown in diagramrnatic form in Fig,2. The cornerstone of the model is a control-volume type thermodynamic simulation of the processes within the engine. In very general terms these modets treat a mUlti-cylinder engine as a series of thentio-dynarriic control volumes, interconnected through valves or ports. Work, heat and mass transfer take place through the boundaries ofthe control volumes. It is required to cajculate tiie work, heat and mass transfer across the boundaries of the control volumes. This is achieved by applying the conservation equations in appropriate fomi to each control volume.
The non steady fiow energy equation fbr an open thermodynamic system may be written, neglecting kinetic and potential energy terms, as follows :
dt dt dt dt ^ '
The rhass conservation equation
M = S r i i , (2)
The State equation (assuming perfect gas) : (3)
V
Thermodynamic property relations obtained from experimental data : U = f,(P.T.cD) (4)
R=f2(P,T,<I») (5)
. ^ (Fuel/Air) actual
where C» = — r - . ~rr-^
(Fuel/Air) stoicliiom.eüic
The control volumes will depend on tiie engine geometry
V = f3(geoinetry) (6)
The U.S.F.E.E (Equation 1) can be manipulated:
t=f,(BÙ,H,^,Q,W) (7)
where
H can be obtained from property data
<t> can be obt^nèd from the sums of air and fuel
Q = Qru.i+QHT where
Q^d=Heat released by combustion
OCT=Heat lost to surröuiuÜngs
dt
Unsteady flow through valves or ports may be tieated in a quasi-steady basis, and using tiie S.F.E.E.
where
can be obtained from property data Tl can be obtained from Equation 7
^orifice ' h® obtained from the engine geometry
Equation 8 can be used in Equation 2 for every related control volume to d^ermine the instantaneous mass, which in tum can be used in Equatipn 3 to determine the instantaneous pressure, which then can be substituted in Equation 8 to find the instantaneous mass fiow.
The above equations are applied to all control volumes ih tum (ihlet
manifolds, cylinders, exhaust manifolds). Each manifold of cylinder w\\\ be a control Volume being successively filled and emptied as fiuid passes through the engine, hence the models have tîeen called "filling and emptying" models. The set of coupled differential equations aire solved step-by-step numerically, for all volumes, using a computer.
A number of additional process sub-models are required, such as for
combustion, heat transfer, scavenging, friction as well as representatiorvs of vartous engine configurations.
The model can predict both the variation of mioo-parameters (such as pressures, temperatures inside the engine cylinders throughout an engine cycle), and also the cumulative macro-parameters (such as heat lost, work, mean effective pressure) in great detail fpr various engine configur^ions. For transient response sirhulation, models for
• the engine governor • the starting air system
• tiie engine remote confrol system • the engine and turixscharger dynamics are atso used.
The engine remote control system mpdel incprporates the logic sequences and time delays associated with the transfer of command signals from the bridge to the propulsion plant.
The variability in engine parameters offered by modem microprocessor regulated systems such ais variable exhaust valVe timing or variable injection timing, can readily be represented by the models referred to above.
The various sut)-models have been described in detail in previous publications [3, 8] and will not be repeated here.
The coupled ship model is shovwi diagramatically in Fig.S. It can be seen tiiat the engine model provides tiie instantaneous engine torqUe, which is compared tp the instantianeous required propeller torque, giving the
immediate change in shaft speed. The initial ship speed is used to calculate the torque and thrust of the propeller in any combination of ship direction anid propeller rotation.
Further, the ship's speed is used to calculate the resistance which is used together with the propeller net thrust in the ship kinetic model. The steering commands are converted through the rudder model to angular displacements and accelerations of the rudder and are also used by the ship kinetic model to deteririine the ships longitudinal and transverse velocities and yaw r^e, which in turn define the instantaneous ship position cpc»xlinates and motion, A more d ^ i l e d exposition of these models can be found in [3].
Thus, when using this integrated set of models, the interaction of engine and ship can be predicted throughput any sequence of manoeuvres.
USING THE MODEL
The model is general enough tp accommodate a very wide combination of engines and ship types. Results for two-stroke engines directiy driving fbced pitch propellers will be presented here.
An enrgine of this type with higher rating than tiie present day series models has been configured, to represent what is expected to be a typical engine of the late nineties, when electronic regulation will probäbly be available.
This engine type was "designed" using tiie model to progressively upgrade a baseline conventional present day engine [3].
A higher rated turbocharger and a power turbine were also induded. The particulars of the engine are shown in Table 1.
The parttoulars of the tanker ship where the engine was purportedly installed for the present series of tests, are shown in Table ll
Table Table Engine partioilars Number of cylinders 5 Bore 60 cm Stroke 264 ö n
Con-rod length 320 can
Compression ratio 18.4
Speed 100 rpm
Max. Power 17500 BHP
Mean piston speed 8.32 m/s
BMEP 20.2 bar
Boost pressure retio 4.5
1
Ship particulars
Length 235 m
Breadth moulded 38 m
Depth moulted 15 m
Full load displacement 105.000 t
Max speed 14.8 kn
Propeller particulars
No. of blades 4
Diameter 7.25 m
Pitch ratio 0.7
Since the model follows the engine events with one or two degrees crank angle resolution, the detail of representation of the events is excellent. For example, the trajectory of the instantaneous engine operating point on the turbocharger compressor map during a crash stop astem manoeuvre of the ship, is shown in Fig.4 [3].
The engine was assumed to be equipped v^th Variable Injection Timing (VIT) and Variable Exhaust Valve Timing (VEC). The sdiedules of vaiation of these parameters were assumed to be the principal means for optimisatian of the engine.
Bomples of using the rhodel predictions for optimisation, are presented below:
a) Optimisation of fuel consumption forWfferent ship loaéng condäions Depending on the loading condition of tiie ship, the weather conditions (sea state) during passage and the huii foulir^, the steady state propeller curve will differ as shown in Fig.5 for tiiree different cases.
Initially the engine was optimised at 70% of MGR corresponding to the "full load/ciean hult/calm sea" conditton increased by 15%. At this point the
turbocharger was matched and the VlTA/EC settings were optimised and adjusted.
Normally it would be expected tiiat the lowest s.lo.c is ot)tained at abput 80% ofthe rating at the optimising point, that is about 0.7 *0.d =0.55of MCR in the present case.
At different loading aind weather conditions the former optimisation is np longer valid. An improvement may be obtained by adjusting the VIT and/or VEC. Shown in Figs 6,7,8 are the s.fo.c curves for the three different combinations of ship loading/hull fouling/ sea state and the reduction in s.f o-c obtained in each case by adjusting the VIT and VEC. (The improvement includes the effect of the turbocompound power turbine). The combination of VIT and VEC atso enables the maximum cylinder pressure to remain constant for a wider load range (down to 70% MCR or more).
In this way a lower sfoc can be obtained at loads where the ship may operate for substantial periods due to charter demands or weather conclitions,
b) Engine response in seaway
In the past as well as recentiy [4], there has been criticism of the use of constant speed governing of engines in iieavy seas, which results in severe fuel rack position variations.
It has often been stated that fuel (toad) control for ships with fixed pitch propeller may be preferat)1e regarding s.f.o.c under these conditions [5]. These options were examined for a scenario where Uie ship is fully loaded with 50% fouled hull and a sea state of about 8 BF (conesponding to a wave height H=6m and a wave period Jw=7.B sec)[6].
Assuming that the ship is sailing in deep v ^ e r (depth of water larger tlian half the wave length, h > Lvv/2), then the horizontal component of thé water velocity at a point z meters below the surface is given as, [6] :
H -kz cos(-k.V,.t+ m ] .cos 2 (-k.V„.t) (9)
k = wave number
V„ = wave velocity or "celerity" L„ = wave length
H= waveheight
z= propeted^^th
- wave encounter frequency
and û), = ûJ+—.V, (10)
g m = wave frequency
where ^ ,
V, = drip speed
This expression is derived assuming simple harmonic sinusoidal waves modified by a hannonic which is half the length of tiie fijndamental wave. Due to the drculation velodty of frie vrater, tiie propeller inflow velooity varies eyen at mocterate seas. Therefore, the propeller inflow velodty is considered as fiuctuating in accordance to the water velocity u.
The hull resistance is considered to be increased due to heavy weather. For simplicity it is assumed that the increase is tim.e4nyarianL
For the conditions in the present example an increase of resistance due tp sea and wind of 10% is assurhed.
With speed control the governor is working as usual. Depending on the vessel's speed and the wave encounter period, the govemor may amplify the fluctuations of engine speed. On the c ^ e r hand if the govemor is eledronic, it may be adjusted to be highly damped so as to be insensitive tb the
propeller speed perturbation due to the waves. Essentially this is equivalent to fuel (toad) control.
In the present example fuel control was realized by keeping the fuel reck position fixed. This position was seleded by trial and error to give the same vessel speed as the engine under speed control.
Figure 9 shows tiie model predidions for engine speed variation with fuel control and speed control.
The predided fiuctuatipn in fuel rack position with speed control can be seen in Fig.10.
The engine torque and load torque variaticMi for the two control modes can be seen in Fig. 11. The differences in the variation of load torque t>6tween the two modes is from the interadipn of shaft speed and the inflow velocity due to the waves on the propeller ctiaracteristics.
Finally, the locus of the instantaneous operating pc»nt of the engine for fuel control and speed confrol superimposed on the steady state propeller curve are shown in Fig.12. The larger excairsions of the operating point under speed control can be observed. It was found that different governor settings (gain) produce considerably different engine responses and perfonnance. Dependent on the govemor gain, the peripatetic trajedory with speed confrol, may eventually be flattened and contraded to an oblong trajectpry
approximating that of load control. It can be seen that if the torque margin is small, as in this case, the engine may be overloaded in bad weather
conditions- In the present example the predicted improvement ih sfbc between fuel controt and speed control mode was 7-11 % (for various govemor settings).
c) Crash stop performance predictions
The braking capability of ships becomes poorer as the size of ship is increasing. (The ratio of braking thrust to DWT being approximately 3 for cargo ships compared to about 0.4 for that of a supertanker [7]). The problem Is further aggravated as the huii effiderKy is improved, resulting in smaller installed power.
For the case presented here, tiie tanker ship used in all examples, is
assumed to be sailing with sea state 6 BF and 30% increased resistance due to hull fouling. Several crash stop manoeuvres were performed, all without rudder intervention. Since the engine is relatively small, in relation to the size of the ship, it was soon obsen^d that engine pvertorque after full reversing, has very limited effed. Therefore the effeds of other regulation sequences were examined.
During the reversing nranoeuvre, the engine is braked with compressed air. Following the fuel cut-off, the admission of reversing air was normally set to commence after the engine has slowed to 30 rpm, so that the cylinder maximum pressure would not exceed a limit of 180 bar.
Shovm in Fig.13 is the reversing manoeuvres ptotted on a Robinson diagram
where the propeller tonüiue ratio Mp/Mp^ and speed ratio Np/Npo is shown for
various ratios of ship speed
V5/V50-Points #A,B.C,D correspond to various stages of the manoeuvre. At point #A tiie fuel is cut, the engine speed drops rapidly (#B) and the propeller trails decelerating the ship, up to the point #C where the shaft speed (engine speed) is low enough (30 rprn) for the engine to be reversed. The reversing sequence is completed at #D.
Shown in Fig.14 is the engine speed, vessel's speed arid sailed distance for the crash stop manoeuvre described above (solid lines). The discontininties observed as the engine speed increases in reverse, are due to individual cylinders firing.
The dashed line in Fig.14 shows tiie revereing sequence but with
compressed air admitted earlier (at 31.5 rpm). In this case the maximum cylinder pressure reaches 210 bar and the engine is tiierefore oversfressed temporarily, but tiiere is a 30 sec difference in response which results in
10Qm cüfference in sailed distanoe at the end of tiie phenomenon (i.e. ap^ox. 10% improvement in stopping distance).
Attempting tp advance the admittance of braking air to the point where the engine speed is 33 rpm, resulted in failure of the engine to reverse, and severe overstressing.
CONCLUSIONS
The continuous monitoring and perfomiance evaluation of propulsion engines, combined v^th the microprocessor based regutatton of engine events, provide increased fiexibility of operation and improved optimisation potential in propulsion engines.
In the near future, it is expected that there will be discreet regulation templates corresponding to specific operational situations, for example economy setting, manoeuvring setting, minimum emissions setting. These will be predetermined fbr the particular engine and ship.
Eventually it can be envisaged that the optimum setting could be dynamically determined based on the actijal condition of the engine and hull and the other prevailing external conditions.
Mathematical modelling can be used to eluddate tiie complex interrelations of the behaviour of engine and ship, especially during fransient events. A comprehensive model of the interaction between engine a i d ship was described arid results form predidions of the model simulating the behavipur of such an engine/ship cpmbinatton for various conditions were presented. It was shown that a model such as the MIMESIS code presented h a ^ can be used as a tool to examine with great precision sgch complex phenomena. Improvements in some sub-models could be desirable especially for the ptatform (ship) behaviour. For example, the present hull resistance model has questtonable performance in manoeuvres. Additionally other ship-environment interadion effeds such as wakes, wind, currerrt, channel and shore boundaries, other ships, are not accounted for in the models used at present.
It must be however mentioned, that this development work vvas primarily intended tp support detailed predictions of the machinery transient behaviour, therefore the ship side was of secondary importance.
Further, the modular design of the MIMESIS code fadlitates the infroduction of more advanced and detailed models wher) appropriate.
One other area for develppment is that of faults modelling. Altiiough various faults can be successfully simulated (e.g. blowby, [8]), the overall
deterioration of performance is the resultant effect of small chartges in many components, v^ich is more difficult to incorporate in a model.
Use of the overall model as a design tool is by no means easy. Since the description of the process is very detailed, the model is quite sensitive to parameter changes. Design changes in tiie propulsion machinery settings, such as changes in exhaust valve timing, require extensive re-optimisation of the engine, as for example in the turbochargermatching. This in tum
requires extensive engine related experience fi^m the user, to achieve convergence with reasonably rapidity.
Although both tiie machinery and the plafform models are not simple, they can be adapted to represent series produdion engines and typical series ships. This adaptation can be facilitated with "tuning coeffidents" to be used in conjunction with data from test-bed trials, model tests and ship frials. The continuing rapid advances in processor capabilities and ^ e e d , ensure that there will be no problems in mnning extensive codes like MIMESIS in "real time" mode, using computational platfonns of modest cost, in the very near future. Thus the integration of such sofiware within engine management systems to provide reference values for optimum engine cpntrdi, is in
principle achievable. ACKNOWLEDGEMENTS
The author wishes to acknowledge the confribution of his Research Assistant Ion Koumbarelis in the preparation of the present paper. Mr. Koumbarelis is currently completing a Ph.D. thesis on "Marine engine transient response".
REFERENCES
[1] Rushby.J., "f=ormal Methods for Dependable Systems^', Proc. IMA Conf. on Mathematics for Dependable Systems, Surrey, Sept. 1993.
[2] TowaAtfs the intelligent engine, hJER, Dec. 1992.
[3] Kyrtatos N.P., Koumbar^s L, "Perfyrmance prediction of
next-generation speed diesel engines during ship manoeuvres^'.
To be published: Trans. I.Mar.E., 1994.
[4] Faber E., "Some thoughts on Diesel Marine Engineering", SNAME Centennial Meeting, New Ypri^, Sept. 1993.
[5] Grossman, G., "Speed controt or fuel control for Motorships vinth
fixedpitch propeHer", 9th Ship Control Systems Symposium,
Maryland, USA. Sept, 1 9 ^ .
[6] F>rinciples of Naval Architecture, SNAME, 1990.
[7] Genyu H., "Or? the crash stop of ships", Proc. 3rd IMAEM Intemational Congress on Marine Technology, Athens, May 1984.
[8] Kyrtatos N.P., "A microcomputer based diesel engine simulator
for advanced ship propulsion moriitoring and control systeni^',
I
8 B1
Q1
S o to I IFIGURES
Ftg.1 Schematic of advanced propulsion engine management system. Fig.2 Propulsion engine rhodel in simplified block diagiram form.
Fig.3 Interaction of engine rhodel with models for hull, rudder and ship kinetics.
Fig.4 Trajedory of instantaneous engine operating point bn the compressor map during a crash-stop astem manoeuvre. Fig.5 Power-RPM curves for 3 load conditions.
Fig.6 SFOC improvement with optimised VIT/VEC setting (Condition 1). Fig.7 SFOC improvement with optimised VIT/VEC setting (Condition 2). Fig.S SFOC improvement with optimised VIT/VEC setting (Condition 3). Fig.9 Engine speed variation with fuel control and speed cpntrol in
seaway.
Fig. 10 Fuel rack index variation with speed control.
Fig.11 Engine torque and Load tprque variation with fijel control and speed control in seaway.
Fig. 12 Trajectory of iristantaneous engine operating point with fuel control and speed control.
Fig.13 Crash stop manoeuvre on Robinson diagram.
Fig.14 Variation of engine speed, vessel speed and sailed distance, for different reversing sequences.
MOIDRSHIP
Towards the Intelligent Engine Kaspar Aeberli
Assistant Vice-President, Two Stroke Engine Development.
New Sulzer Deisel
Bom on the shores of the Lake of Zürich, he graduated as mechantoal engirœer at the Sw\88 Federal Technical University (ETH) in Zürich in 1971. He began his involvement v«tti Sulzer diesel engines in 1972 and since 1987 has been responsi-ble for tiie development and design of Sulzer two-sfroke diesel engines.
TOWARDS THE 'INTELLIGENT ENGINE'
SUMMARY
An 'intelligent engine' can be meaningfully defined as an engine whose performance in terms of reliability, operational economy fiexibility and maintenance requirements is self-optimizing on tiie basis pf the particular preferences of the operator
It would also extend the current scope of condition monitoring and fault diagnosis sys-tems, in being self coneding to avoid faults. The 'intelligent engine' may also be asso-ciated with computer-based management features, for example maintenance planning and spare parts control.
The 'intelligent ^ g i n e ' is a long-tmn projed at New Sulzer Diesel Ltd and it is envis-aged that it will bring clear benefits fpr shipowners and ship operatoris.
The paper addresses various aspects ofthe 'intelligent engine'. It outlines those ele-ments Vilich have already been developed and implemented by New Sulzer Diesel Ltd, and indicates a pradical path forward.
INTRODUCTION
The 'intelligent engine' is a new expression of which everyone has their own percep-tions. It is not yet on the market and its charaderisttos are not yet fully defined. How-ever, progress is being made towards a new generation of engine control, alarm and condition monitpring which will result in what, for convenience, v^re can call the 'intelli-gent engine".
This is a long-term projed. Thus we are not going to announce that the 'intelligent, engirt' is now here. Instead we shall show the progress already made towards the 'flitelligent engine' and outline the next steps. As an introdudion of the subjed, how-e v ^ , whow-e nhow-ehow-ed to addrhow-ess a numbhow-er of fundamhow-ental quhow-estions.
WHAT DO WE UNDERSTAND BY ÎNTËLLIGENCE'7
According to a didionary, 'intelligence' is the capacity for understanding, or the ability tp perceive and comprehend meaning. It is usually recognized as a uniquely-human attribute.
Although the expression 'intelligent engine' is perhaps misleading, it has become a convenient expression for an engine equipped with something more sophisticated than the control, alarm and condition monitoring equipment (Uie engine management sys-tem) which is now usual in modern ships. The key step is that the 'intelligerrt engine' will have an 'intelligent engine-management systern' which will effectively close the feedback loop by enabling it to use built-in 'expert knowledge' to adjust its
At present, feutts sensed by tiie monitoring system trigger alarms and in extreme cases the slowing down, or stopping of tiie engine. Ultimately an 'inteltigent engine' would instead diagnose the jxoblem and then initiate remedial action. Instead of reacting to faults after tiiey have arisen, the 'intelligent engine' would use ite built-in 'expert knowl-edge' in an effort to antidpate difficulties and thereby avpid faults.
The 'expert knowledge' would go much forther than dealing with faults. Feedback con-frol would also give the engine tiie fiexibility to maintain optimum performarKse auto-matically under various individual circum^ances without manual intervention. It would tiiereby enable tiie ship's engineers to seied tiieir preference for tiie engine's operating criteria to suit tiieir ship's prevailing requirements. For e>âmple, there could be prefer-ences for optimizing the engine for low fuel consumptton or low âichaust gas emissions, or to suit long periods of 'slow steaming'.
The development of tiie 'intelligent engine' is drawing on the tremendous advances in computers and tiieir software being made today. It would really be a 'high-tech' engine. The basic engine would itself be technotogicalty advanced and, in ite physical design, would offer significant improvemente in reliability durability and also opereting fiexibil-ity. Its engine management system would be much further integrated with the engine than with today's control, alarm and condition monitoring systerns.
Such an 'intelligent engine-management system' may also be taken a step further by cpnceming not only the engine operation but also induding management features, for example maintenance planning and spare parts control.
W H E R E IS THE RESPONSIBILITY?
The 'intelligent engine' would be a fairly sophisticated propulsion package, even though the complexity would be hidden from the user by what is known in the computer indus-try as a 'user^riendly' interface. Although it involves a marriage of traditional diesel engineering skill and the latest computer technology its design and manufacture would remain the responsibility of the engine designer and builder just as with tpda/s en-gines.
It needs to be clear, however, that here we are not referring to 'unmanned' engines. There would still be the need for qualified ships' engineers. The 'intelligent engine' would offer the engineers more options for engine operation and would proyide more information, in a user friendly way about its operation and condition. Yet there would remain the need for overall supervision to obtain the best from the engine's e x t ^ d e d capabilities. There would also riemain the many other duties in a ship's engine room. WOULD IT B E A C C E P T E D IN THE MARINE ENVIRONMENT?
Shipovmers and ship operators are naturally cautious people. With their ships laden with valuable cargoes voyaging the world's oceans far from port, they are often wary of new technotogy Yet, if a new technical development can be demonstrated to offer clear benefits, many owners are ready tp adopt it. Thus, new developments need to be led by market requirements tp ensure their commCTCial viability.
The basis of judging whether a new devetopment is worth adopting is nomially a bal-37
ance between tiie cost outlay involved and the added value of any resulting benefits. If an 'intelligent engine' is to be a commerciaj proposition, it must offer the user significant gains in terms of, for example, lov^rfuel costs, lower maintenance costs, compliance with exhaust emissions legislation, better safety, less dependence on personnel, etc. Other less tangible fadors also become involved in tiie acceptance of new technology but, in the case of the 'intelligent engine' and ite electronic systems, shipboard eledron-ics and personal computers are today widely used, and shipboard personnel are be-coming increasingly familiar with tiiem. It is also recognized that the reliability of elec-tionic equipment has considerably improved.
It needs to be understood, however, that the introduction of 'intelligent engines' would call fpr a fondamental change in thinking by the engine user as wet) as by the engine designer to obtain the greatest benefits.
OPPORTUNITIES FOR THE 'INTELLIGENT ENGINE'
It is envisaged that the addition of 'intelligence' to a marine engine will offer id^tifiable added value to the ovmer and user. This may arise in vartous ways, for exanple:
• To help make the engine less dependent on the numbers and skills of shipboard personnel;
• By tending to avoid faults by picking up irregularities at the eariiest stage;
• By improving the predidability of engine maintenance requirements and thereby allowing better planning of overhauls;
- To help meet the imposition of regulations, such as those antidpated for ^ a u s t emissions;
• To give the engine the added fiexibility to cope with a wider range bf foel qualities. As engine designers, we perceive four main areas of development trends for marine diesel engines, each of which is infiuenced by the prosj^ed of 'intelligent engines': • Reliability, durability and availability are pf continuing importance and can be
improved in different ways:
- By inherent design of the engine;
- By monitoring, engine protedion through on-line measurement bf 'health' and even self correction;
- By changing maintenance philosophies using new maintenance systems witii expert knowledge.
The 'intelligent engine-management system' itself would not give tiie engine greater durability as expressed by longer times between overhauls. It could, however, im-prove the reliability - that is the probability of reaching tiie planned time k)etween overiiauls. The maintenance requiremerrts of an 'intelligent engine' wouW thus be even more predtdable than witii today's engines.
• Operating economy is of continual concem but tiiis involves several fodors, iri-dudir^:
- Fuel consumption
- Fuel oil quality adaption - Lubricating oil consumption
