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Title:
CONTROL SYSTEM FOR MARINE VESSEL
Document Type and Number:
WIPO Patent Application WO/2008/035062
Kind Code:
A2
Abstract:
The present invention relates to a control system for a marine vessel, and in particular a system that integrates control of a plurality of machine components required to operate the vessel. This is achieved using a data network connecting the machine components to a control server. The control server receives sensor data from at least some of said machine components over the data network, automatically generates appropriate control signals, and sends the control signals to the machine components. The control server comprises control logic implemented in software that is used to carry out automatic generation of the control signals.

Inventors:
HINTON TIMOTHY JAMES (GB)
Application Number:
PCT/GB2007/003545
Publication Date:
March 27, 2008
Filing Date:
September 19, 2007
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
NORTHROP GRUMMAN SPERRY MARINE (GB)
HINTON TIMOTHY JAMES (GB)
International Classes:
B63H21/22
Domestic Patent References:
WO2006021530A12006-03-02
Foreign References:
JPH01187611A1989-07-27
US20040243859A12004-12-02
Other References:
PETERSEN S T: "THE COMMAND, CONTROL, COMMUNICATIONS AND INFORMATION SYSTEM" STANDARD FLEX 300. TRUE MULTI-ROLE SHIP, March 1992 (1992-03), pages 10-11, XP002130723
CHOU L-D ET AL: "DESIGN OF SHIPBOARD LAN AND INTERWORKING TO THE INTERNET" GLOBAL INFORMATION INFRASTRUCTURE (GII) EVOLUTION: INTERWORKING ISSUES. INTERWORKING '96. THIRD INTERNATIONAL SYMPOSIUM ON INTERWORKING. NARA (JAPAN), OCT. 1-3, 1996, AMSTERDAM, IOS, NL, 1 October 1996 (1996-10-01), pages 392-401, XP000754586 ISBN: 90-5199-290-4
Attorney, Agent or Firm:
PALMER, Jonathan, Richard et al. (Verulam Gardens70 Gray's Inn Road, London WC1X 8BT, GB)
Download PDF:
Claims:

CLAIMS :

1. A marine vessel control system for controlling a marine vessel having a plurality of machine components used to operate the vessel, the control system comprising: a data network; a control server coupled to the data network and arranged to receive sensor data from at least some of said machine components over the data network, to automatically generate appropriate control signals at least partly in response to said sensor data, and to send said control signals to at least some of said machine components over the data network to thereby operate the vessel ; and a plurality of in/out elements, each in/out element coupled to the data network and to at least one machine component, each in/out element arranged to provide communication of at least one of said sensor data and control signals between said at least one machine component and the control server; wherein the control server comprises control logic implemented in software, said control logic being adapted to carry out said automatic generation of control signals.

2. The control system of claim 1 wherein the server further comprises at least one in/out driver implemented in software, each in/out driver being adapted to interface, over said network, between said control logic and at least one in/out element.

3. The control system of claim 1 or claim 2 wherein the control server comprises a server interface process adapted to generate graphics data defining a human machine

interface, the human machine interface being operable by a user at a user terminal to view an operational state of the control system and to guide the automatic generation of control signals by the server.

4. The control system of claim 3 further comprising a plurality of said user terminals, each user terminal comprising graphics logic adapted to process the graphics data to present the human machine interface to a user.

5. The control system of claim 3 or 4 wherein said graphics data is constrained by a graphics data protocol independent of the control system, such that the terminal graphics logic is also independent of the control system.

6. The control system of claim 5 wherein the graphics data protocol is an XIl protocol.

7. The control system of any of claims 3 to 6 wherein said network comprises an Ethernet network constructed from one or more rings to which the control server, the in/out elements and the user terminals are attached.

8. The control system of any of claims 3 to 7 wherein the server interface process is arranged to serve graphics data defining the human machine interface to a terminal only if that terminal has completed a logon process with the server interface process, the logon process identifying a username known to the server interface process.

9. The control system of claim 8 wherein each username is logically assigned to one of two or more levels in a

hierarchy of username levels, and the server interface process restricts the degree to which a user at a terminal can guide the automatic generation of control signals according to the level of the username identified in the logon process.

10. The control system of claim 9 in which the human machine interface is divided into a plurality of discrete control functions, and the server interface process is adapted to restrict use of members or groups of at least some of the control function to only one user at a time.

11. The control system of claim 10 wherein the server interface process is adapted to allow a user at a higher level in the hierarchy to wrest control of a control function or group of control functions from a user at a lower level in the hierarchy.

12. The control system of any of claims 3 to 11 further comprising a radar control computer operably coupled to a radar antenna unit, and adapted to provide a radar control interface to display data from and send control signals to the radar antenna unit, the radar control computer further comprising graphics logic adapted to process the graphics data to present the human machine interface generated by the server interface process to a user of the radar antenna unit.

13. The control system of claim 12 wherein the radar control interface further comprises a switch control operable to activate the human machine interface on the radar control computer.

14. The control system of any preceding claim wherein the machine components comprise one or more of an engine, a pump, an electrical generator, an electrical breaker, a valve, an alarm unit, a steering controller, a hull speed sensor and navigation equipment.

15. The control system of any preceding claim wherein the control server is provided by a single computer unit .

16. The control system of any preceding claim wherein the control server is duplicated with at least one shadow control server arranged to take over control server operation in case of failure of the control server.

17. The control system of any preceding claim wherein the network comprises a plurality of rings to which the control server and the in/out elements are connected, the plurality of rings being arranged such that two or more deck rings extend to cover respective decks of the vessel and are linked by one or more connecting rings.

18. The control system of claim 17 wherein each deck ring is connected to a connecting ring at two points of intersection.

19. The control system of claim 17 or claim 18 wherein the network is an Ethernet network.

20. A marine vessel control system for a marine vessel which is operated using a plurality of machinery systems, the control system comprising:

a plurality of user terminals from which system defined user identities can access the control system; a control server providing a set of control functions for controlling the machinery systems, wherein the control server provides, to a user identity, access to a subset of said remote control functions which is dependent on the user identity.

21. The control system of claim 20 wherein the control server provides access to any one control function to only one user identity at a time.

22. The control system of claim 20 or 21 wherein each user identity is assigned to a level in a hierarchy of user identity levels, and the subset of control functions to which the control server allows a user identity access is dependent on the identity level of that user identity.

23. The control system of claim 22 wherein the control system is adapted to accept and action a request from a user identity at a higher level to move access to a control function from a user identity at a lower level in the hierarchy, to the user identity at the higher level.

24. A marine vessel control system for controlling a marine vessel having a plurality of machine components used to operate the vessel, the control system comprising: a data network; a control server coupled to the data network and arranged to receive sensor data from at least some of said machine components over the data network, to automatically generate appropriate control signals at least partly in

response to said sensor data, and to send said control signals to at least some of said machine components over the data network to thereby operate the vessel; and a plurality of in/out elements, each in/out element coupled to the data network and to at least one machine component, each in/out element arranged to provide communication of at least one of said sensor data and control signals between said at least one machine component and the control server; wherein: the control server comprises a server interface process adapted to generate graphics data defining a human machine interface; and the control system further comprises a radar control computer operably coupled to a radar antenna unit, and adapted to provide a radar control interface to display data from and send control signals to the radar antenna unit, and wherein the radar control computer further comprises graphics logic adapted to process the graphics data to present the human machine interface generated by the server interface process to a user of the radar antenna unit.

25. The control system of claim 24 wherein the radar control computer is adapted to allow the user to view an operational state of the control system and to guide the automatic generation of control signals by the server.

26. The control system of claim 24 or claim 25 wherein the radar control interface further comprises a switch control operable to activate the human machine interface on the radar control computer.

27. The control system of any of claims 24 to 26 further comprising a user terminal for displaying the human machine interface to a user thereby allowing the user to view an operational state of the control system and to guide the automatic generation of control signals by the server.

28. A marine vessel control system for controlling a marine vessel having a plurality of machine components used to operate the vessel, the control system comprising: a data network; a control server coupled to the data network and arranged to receive sensor data from at least some of said machine components over the data network, to automatically generate appropriate control signals at least partly in response to said sensor data, and to send said control signals to at least some of said machine components over the data network to thereby operate the vessel; and a plurality of in/out elements, each in/out element coupled to the data network and to at least one machine component, each in/out element arranged to provide communication of at least one of said sensor data and control signals between said at least one machine component and the control server; wherein the network comprises a plurality of rings to which the control server, the in/out elements and the one or more user terminals are connected, the plurality of rings being arranged such that two or more deck rings extend to cover respective decks of the vessel and are linked by one or more connecting rings.

29. The control system of claim 28 wherein each deck ring is connected to a connecting ring at two points of intersection.

30. The control system of claim 28 or claim 29, wherein the network is an Ethernet network.

31. A marine vessel comprising the marine vessel control system of any preceding claim.

32. A method of controlling a marine vessel having a plurality of machine components for operating the vessel, comprising: providing a data network in communication with the machine components; providing a control server coupled to the data network; automatically operating the control server to receive sensor data from at least some of the machine components over the network; and automatically operating the control server to generate appropriate control signals at least partly in response to said sensor data, and at least partly in response to user guidance inputs, and sending said control signals over the data network to at least some of the machine components to thereby operate the vessel.

33. The method of claim 32 further comprising: automatically operating the control server to generate graphics data defining a human machine interface operable at one or more user terminals to view an operational state of the vessel and to provide said user guidance inputs to guide

the automatic generation of control signals by the control server.

34. The method of claim 33 wherein the graphics data is constrained by a graphics data protocol which is independent of the control system.

35. The method of any of claims 32 or 34 further comprising connecting the machine components to the data network using a plurality of in/out elements such that each in/out element provides communication of at least one of sensor data and control signals between at least one machine component and the control server.

36. The method of claim 35 wherein the network is constructed of one or more rings to which the control server, the in/out elements and the one or more user terminals are connected.

37. The method of claim 36, wherein the network is an Ethernet network.

38. The method of any of claims 32 to 37 further comprising accepting user guidance inputs from a plurality of different users.

39. The method of claim 38 further comprising dividing said operation of the vessel into a plurality of discrete control functions generated automatically by the control server at least partly in response to corresponding ones of said user guidance inputs, and operating the control server to restrict access to user guidance inputs corresponding to a

particular discrete control function to a single user or a predefined subset of users.

40. The method of claim 39 wherein the users are ordered in a hierarchy and further comprising accepting, at the control server, an instruction from a user higher in the hierarchy to wrest access to a subset of said discrete control functions from a user lower in the hierarchy.

41. A method of controlling a marine vessel having a plurality of machine components for operating the vessel, comprising : providing a data network in communication with the machine components; providing a control server coupled to the data network; automatically operating the control server to receive sensor data from at least some of the machine components over the network; and automatically operating the control server to generate appropriate control signals at least partly in response to said sensor data, and at least partly in response to user guidance inputs provided by a plurality of different users, and sending said control signals over the data network to at least some of the machine components to thereby operate the vessel; and wherein the method further comprises dividing the operation of the vessel into a plurality of discrete control functions generated automatically by the control server at least partly in response to corresponding ones of said user guidance inputs, and operating the control server to restrict access to user guidance inputs corresponding to a

particular discrete control function to a single user or a predefined subset of users.

42. The method of claim 41 wherein the users are ordered in a hierarchy and further comprising accepting, at the control server, an instruction from a user higher in the hierarchy to wrest access to a subset of said discrete control functions from a user lower in the hierarchy.

43. A method of controlling a marine vessel having a plurality of machine components for operating the vessel, comprising: providing a data network in communication with the machine components; providing a control server coupled to the data network; providing a radar control computer operably coupled to a radar antenna unit, and adapted to provide a radar control interface to display data from and send control signals to the radar antenna unit, automatically operating the control server to receive sensor data from at least some of the machine components over the network; and automatically operating the control server to generate appropriate control signals at least partly in response to said sensor data, and at least partly in response to user guidance inputs, and sending said control signals over the data network to at least some of the machine components to thereby operate the vessel; wherein the control server further comprises a server interface process adapted to generate graphics data defining a human machine interface, the human machine interface being operable by a user at a user terminal to view an operational

state of the control system and to guide the automatic generation of control signals by the server; and wherein the radar control computer further comprises graphics logic adapted to process the graphics data to present the human machine interface generated by the server interface process to a user of the radar antenna unit .

Description:

CONTROL SYSTEM FOR MARINE VESSEL

Field of the invention

The present invention relates to a control system for a marine vessel, and in particular a system that integrates control of a plurality of machine components required to operate the vessel .

Discussion of the prior art Integrated control systems for ships are known, for example, from JP1187611, US2004/243859 and WO2006/021530. US2004/0243859 describes an automation and platform management system for naval vessels. The system can be operated from a multimedia information and control centre which resides on a dual redundant fibre optic backbone ring bus also carrying a master server and a number of continuously updated standby servers. A logistics server is connected via a redundant Ethernet connection to a plurality of local process units. Each local process unit is connected by Profibus (RTM) lines to peripheral units such as actuators and sensors .

WO2006/021530 describes a ship comprising a network integrating security, control, and multimedia and infotainment services embodied as a redundant ring.

Summary of the invention

It is an object of the invention to provide a control system for a vessel which addresses deficiencies and problems in the related prior art. It is also an object of the invention to provide a marine vessel control system which provides improved

flexible but controlled access to control functions to users of the control system.

It is also an object of the invention to provide a control system for a marine vessel which provides more flexible implementation of user terminals.

Accordingly the invention provides a marine integrated monitoring and control system in which aspects such as the programmable logic control of machine systems, alarm monitoring, construction of graphical data for serving to user terminals, and associated database functionality are provided in a single server environment, which is preferably duplicated for redundancy in case of server failure.

The invention also provides such a control system using thin client graphical display terminals over an Internet Protocol network.

The invention also provides such a control system using disseminated hierarchical control as the system topology, by use of unique user assignment, in which a particular user at any terminal is allowed control of a particular sub-set of machine systems on a user interface page-by-page basis. No two users are allowed control of the same systems concurrently, and user access levels are incorporated as a hierarchy, allowing users higher in the hierarchy to wrest control of users lower in the hierarchy as required. All available system functionality is tailored to a user's level in the hierarchy.

The invention also provides integration of a marine control system with a dedicated RADAR monitoring console, through use of a graphical display protocol such as X- windows over an IP network, and similarly, integration of a real-time CCTV display within a dedicated RADAR monitoring console over an IP network.

In particular, the invention provides a marine vessel control system for controlling a marine vessel having a plurality of machine components used to operate the vessel, the control system comprising: a data network; a control server coupled to the data network and arranged to receive sensor data from at least some of said machine components over the data network, to automatically generate appropriate control signals at least partly in response to said sensor data, and to send said control signals to at least some of said machine components over the data network to thereby operate the vessel; and a plurality of in/out elements, each in/out element coupled to the data network and to at least one machine component, each in/out element arranged to provide communication of at least one of said sensor data and control signals between said at least one machine component and the control server; and wherein the control server comprises control logic implemented in software, said control logic being adapted to carry out said automatic generation of control signals. The control system provides both monitoring and control functions at a plurality of user terminals. In particular, a user at a control terminal may guide the automatic generation of control signals by providing user guidance inputs. Machine components may include both passive and active components such as sensors, actuators, mechanical and electrical devices and system components such as engines, generators and navigation equipment. Accordingly, an in/out element may provide data flow to, from, or both to and from a machine component . The control server is preferably provided by a single computer unit, but with duplication of the server by at

least one duplicate server arranged to take over control server operation in case of failure of the main unit.

The system omits the conventional separate programmable logic controllers (PLCs) found in the prior art, and instead uses PLC functionality implemented on the control server in software. Preferably, the server further comprises at least one in/out driver implemented in software, each in/out driver being adapted to interface, over said network, between said control logic and at least one in/out element . The control server also preferably comprises a server interface process adapted to generate graphics data defining a human machine interface, for example in an X-windows or another standard GUI protocol , the human machine interface being operable by a user at a user terminal to view an operational state of the control system and to guide the automatic generation of control signals by the server. By serving GUI graphical data to the user terminals, the user terminals can be implemented as thin clients, with increased flexibility in choice of client hardware, siting and mobility, and combination with our vessel computer terminal and display functions.

The network is preferably an Ethernet network constructed from one or more rings to which the control server, the in/out elements and the user terminals are attached.

The server preferably provides a user logon process for access from terminals, for example using user names and passwords, so that access to control functions is largely or entirely independent of which user terminal is used for access.

Each username or user identity is preferably assigned to one of two or more levels in a hierarchy of username

levels, and the server interface process restricts the degree to which a user at a terminal can control the vessel and its systems. In particular, control may be delimited by functions or groups of functions, by GUI pages or screens and so on, and the server interface process is preferably adapted to restrict use of members or groups of at least some of the control functions to only one user at a time.

Preferably, the server interface process is adapted to allow a user at a higher level in the hierarchy to wrest control of a control function or group of control functions from a user at a lower level in the hierarchy.

The invention also provides a radar control computer operably coupled to a radar antenna unit, and adapted to provide a radar control interface to display data from and send control signals to the radar antenna unit, the radar control computer further comprising graphics logic adapted to process the graphics data to present a human machine interface generated by a server interface process of a marine vessel control system, for example as set out above, to a user of the radar antenna unit.

The invention also provides a control system for a marine vessel which is operated using a plurality of machinery systems, the control system comprising: a plurality of user terminals from which system defined user identities can access the control system; a control server providing a set of control functions for controlling the machinery systems, wherein the control server provides, to a user identity, access to a subset of said remote control functions which is dependent on the user identity. The invention also provides a ship, boat or other vessel incorporating the control system set out above, operably coupled to machine components to monitor and

control operation of the vessel. The invention also provides a method of operating a vessel in accordance with the invention and computer software, including such software written onto a computer readable medium, for effecting the control server of the invention on a suitable computer system.

Other aspects of the invention and features of preferred embodiments of the invention will be apparent from the appended claims.

Brief description of the drawings

Figure 1 illustrates, schematically, a ship or other marine vessel within which an integrated control system of the present invention may be employed; Figure 2 illustrates an integrated control system according to a first embodiment, with programmable logic controller (PLC) , data server (DS) and human machine interface (HMI) layers between in/out control of machine components (20) and user terminals (54) ; Figure 3 shows the DS, HMI and user interface elements of figure 2 in more detail;

Figure 4 illustrates an integrated control system according to a second embodiment, with control server (110) , user terminal (116) and in/out (I/O) elements (114) connected to a common network;

Figure 5 shows in more detail an I/O element of figure 4 and connections to machine components;

Figure 6 shows in more detail the control server of figure 4 ; Figure 7 illustrates a user interface window built from graphics data served by the HMI process of figure 6 ;

Figure 8 shows a hierarchy of user interface windows;

Figure 9 illustrates a plurality of levels, defined as a hierarchy, to one of which a user account for using the user interface must belong;

Figure 10 illustrates access to the control system of figure 4 at a RADAR terminal; and

Figure 11 shows example RADAR and control system interface windows presented at the RADAR terminal of figure 10.

Detailed description of preferred embodiments

Figure 1 illustrates, schematically, a ship or other marine vessel 10 within which an integrated control system embodying the present invention may be employed. The vessel 10 includes a number of machine components which provide the operational functionality of the vessel. In figure 1 the machine components include an engine 12, a steering control 14, a bilge pump 16 and an electrical generator 18. Of course, many other machine components will be required or desirable for a typical vessel . Although many components will require control and provide sensory feedback, some of the components may act only as sensors, such as a hull pressure gauge, a depth gauge, a cooling water temperature gauge or navigation equipment, and some may only require control, such as a cabin heating device, an electrical isolator, or fire or other alarm, a valve or a motor.

Associated with each machine component is an in/out (I/O) element 20 which serves to connect the component to an automatic control function 22 via a communication connection 24. The communication connections 24 could, in general, be provided by a single common data network or by multiple data networks, or by dedicated control lines. The automatic control function 22 is typically provided by computer

hardware suitably programmed and may be centralised at a single place such as a machine control room 26, or may be distributed across the vessel.

Human control over the automatic control function 22 is provided by terminals typically located at a bridge 28, as well as at a machine control room 26 or similar where the automatic control function 22 may be at least in part located. The terminals may be computers implementing a graphical or other human machine interface . Figures 2 and 3 illustrate a first way in which an integrated control system as shown in figure 1 may be implemented, by using dedicated programmable logic controllers. In figure 2 the I/O elements 20 are connected to machine components such as those discussed above which, for clarity, are not shown. The I/O elements 20 may be Rockwell Flex (RTM) units which include a Controlnet backbone into which are plugged hot swappable functional units- of various types as required by the particular machine component for control and sensor feedback, such as power relays, analogue voltage and current inputs, digital inputs and so on. The I/O elements 20 are connected to an industry standard "Controlnet" serial protocol network 40 with suitable redundancy provision, which connects the I/O elements 20 in a robust manner to a programmable logic controller 42.

The programmable logic controller 42 may be provided by a Rockwell CLX (RTM) unit or system which runs dedicated control algorithms programmed in ladder logic and stored in FLASH or other non volatile memory at the controller 42. At least one second, identical programmable logic controller 44 is provided in case of failure of the first controller 42.

The programmable logic controller 42 is connected to a data server 46 running dedicated Rockwell database software. The data server 46 stores control variables and diagnostics to be used by and reported back from the programmable logic controller 42. Again, redundancy is provided in the form of a second data server 48 which promptly takes over if the first data server fails.

The data server 46 is connected to a human machine interface (HMI) server 50, which provides an interface between the data server 46 and a number of user terminals 54 which are connected to the HMI server by a management network 56. Redundancy is provided by a second HMI server 52.

The programmable logic controllers 42,44, the data servers 46,48 and the HMI servers 50,52 are typically all provided by separate hardware components, such at separate computers, at a common location such as a machine or control room 26, and together constitute the automatic control function 22 illustrated in figure 1. The data servers, HMI interfaces, terminals and other associated components are illustrated in more detail in figure 3. The data server 46 is a computer unit which runs a data server process 60 which reads from and writes to a database 62 as described above. The data server 46 includes an interface 63 between the data server process 60 and the programmable logic controller 42 (not shown) , and an alarm process 64. The alarm process monitors, through the data server process 60, the status of various processes in the vessel and signals to an alarm unit 66 if any status requires this. For example, an alarm could be triggered by low voltage output of an electrical generator, or by low oil pressure in an engine. The alarm unit triggers alarms 68

which may be audible, visual or both, and carried by personnel or located in particular or multiple locations throughout the vessel .

The HMI server 50 is a computer unit which runs a human machine interface (HMI) process 70 under the control of HMI process parameters 72. The HMI process accesses the data server process 60 through a data server interface 74. Communication with terminals 54 is through a number of terminal interfaces 76, each of which communicates with a terminal 54 over the management network 56.

The terminals 54 illustrated in figure 3 are of two different types, distinguished by the software being run at each terminal. Display client terminal 80 executes a dedicated display terminal application which enables a user to access, through the HMI interface, information stored in the data server 46, but not to make any changes or to control any aspect of the vessel machine components. Control client terminal 84, on the other hand, executes a slightly different dedicated control terminal application 86 which enables a user both to read parameters stored on the data server 46 and to control machine components indirectly by changing such parameters. In practice, display and control terminal applications may combine elements of display and control subject to the intended role of the terminal and also dependent on allocated permissions of a user logged on to the terminal .

The terminal applications 82, 86 in their various forms carry out any graphics generation and processing required to interpret and display data received from the HMI server 50, and to prompt a user to input data. In this sense, the terminals act as fat clients of the HMI server 50, with the terminal applications comprising programming logic

specifically adapted for handling data related to the control of the vessel. The HMI process 70 does not contain any programming logic relating to the graphical layout and display of data relating to the control of the vessel, but only logic relating to the data itself.

Figure 4 to 7 illustrate a second way in which an integrated vessel control system as shown in figure 1 may be implemented, using machine component control logic implemented in software on a control server, rather than by using dedicated programmable logic controllers.

In the network arrangement illustrated in figure 4, the hierarchical arrangement of separate functional layers shown in figure 2 has been abandoned in favour of a single network layer. Although a wide variety of network configurations are possible, in this case a main ring 100 is connected to a number of sub rings 102, 104, 106, either directly, or indirectly as between the main ring 100 and sub ring 106. Advantageously, the main ring could circulate around the vessel in a substantially horizontal plane at one level, while particular sub rings, connected to the main ring by routers 108 could circulate around the vessel in substantially vertical planes to reach other levels, thus providing efficient coverage of the entire vessel as shown in the cartoon 110 which puts the network rings into the context of a ship.

The network rings are preferably provided using a widespread industry standard such as Ethernet. For example, the main ring 100 could be provided by 1 Gbit optical fibre or 100 baseT twisted pair cable, with the sub rings being provided at the same specification, or at lower data rate specifications if appropriate. Each ring is preferably bridged to another ring by at least two bridges 108 to

provide redundancy in the case of failure of a network bridge, or failure of a ring at two points.

I/O elements 114, and human control and display- terminals 116, may be connected to the network at any point. To the network are also connected a wireless router 110 and a satellite communications router 111. These routers enable access to the network, for example to monitor the control system or to control the vessel in some way, both from wireless equipped terminals in or in the vicinity of the vessel, and from anywhere else which can connect through a linked satellite communication system.

The automatic control function 22 for the vessel is implemented in a single control server 110, which is duplicated by at least a second control server 112 for redundancy in case of failure. The control server 110 is in communication with the various machine components (not shown) over the network, through the I/O elements 114, and with vessel personnel , who can thereby intervene in the otherwise automatic control, through the terminals 116 over the same network.

An I/O element 114 as used in the arrangement of figure 4 is illustrated in more detail in figure 5. Instead of using Rockwell Flex I/O elements as discussed in connection with figure 2, the illustrated I/O element includes an Ethernet switch 120, a power supply unit 122 and a control module Terminator I/O 124 supplied by Automationdirect , 3505 Hutchinson Road, Cumming, GA 30040, USA, although clearly a variety of other configurations, types and sources of components could be used. These components are mounted on an industry standard DIN rail mount, and specific I/O modules

126 are mounted on the control module 124. The specific I/O modules can be used to control and/or receive signals from

machine components such as a pump 128, an electrical breaker 130 and a valve 132. Connected directly to the Ethernet switch 120 is a serial I/O unit 134 which bridges between the Ethernet ring 102 and industry standard RS232, RS485 and MODBUS connections 136 for communicating with machine components already provided with RS232 interfaces, such as an engine controller 138 and a fire alarm 140.

Figure 6 illustrates in more detail the control server 110,112 of figure 4. The server is implemented on a robust marine approved PC type computer running a Linux or MS Windows operating system. The server provides various commonplace functions such as a TCP/IP facility 140 coupled to a network card 142 which connects to the main network ring 100, as well as (not illustrated) a non volatile file system, volatile memory, a multi threaded kernel and so forth. A server application 144 executes on the server 110, and includes a number of functional components. A server application database 146 holds parameters relating to the machine components monitored and controlled by the system, as well as parameters relating to the operation of the server application 144, network 100,102,104,106 and human control terminals 116.

A Human Machine Interface process 148 has access to read from and write to the database 146, and includes a graphical component 150 which constructs the details of the interface to be presented at each terminal 116 in the XIl graphical protocol, defining windows and window areas and their content, and function graphical elements such as buttons, sliders and text boxes for use at the terminal. The graphical component communicates with the terminals 116 using the TCP/IP interface 140. Because the terminals are served directly with data defining the graphical interface

to be displayed, the terminals can be implemented as thin clients with programming logic to understand and implement the interface graphics served by the HMI process, but with no programming logic directly implementing control processes relating to the vessel itself. The terminals can therefore be implemented, for example, as XIl terminals, although a variety of other graphical interface standards could be used such as HTML, Flash and so on.

The HMI process 148 implements a system of access rights controlling the extent to which particular terminals or users of the system can control the machine components, alarms, network and the control system itself. This system of access rights, which is discussed in more detail below in connection with figure 10, is determined using a set of access parameters 151 to which the HMI process 148 has access . These access parameters may be stored in database 146 along with other operational control parameters.

The automatic logical control of the machine components is implemented in software in a Soft PLC process 152 on the basis of process control logic 154 stored at the control server. The soft PLC process has access to read process parameters from and write such parameters to the database 146, and communicates with the machine components through a data collection and control service 156. The data collection and control service incorporates a number of I/O drivers 158 specifically adapted to interface with the I/O elements 114, over the network through the TCP/IP function 140 and the network card 142.

The server application 144 also includes a redundancy function 160. This function connects to one or more other servers 112 through a second network card 162 and a dedicated communications link 164. In this way, the one or

more backup servers 112 are always kept concurrent with the main server and can take over at any time should the main server fail for any reason.

The server application may be implemented using a commercially available systems control product such as "AutbmationX" (RTM) from Industrial Automation GmbH Teslastrasse 8, A-8074 Grabach, Austria.

Aspects of a graphical user interface presented by the HMI process 148 at a terminal 116 are illustrated in figure 7. In particular, an interface window 180 for a diesel generator is shown. Below the generator window 180 is an alarm window 182 which is always displayed on the terminal and lists recent alarms generated by the server application 144. The generator window includes a graphical image 184 representing the generator in question, including an interface button 186 which provides functionality to stop the generator, for example in an emergency. Other graphical interface elements 188 either provide information about the generator, such as the frequency and voltage of the output, control functions, or both.

A plurality of interface windows similar to that illustrated in figure 7 are generated by the HMI process in order to provide comprehensive control of and information about the vessel machine components. As illustrated in figure 9 these may be mutually ordered, for example in a tree structure or similar. According to aspects of the user interface illustrated in figure 8, a main menu window 190 provides initial access to the control system. From the main menu window a number of second level windows 192 relate to specific subsystems such as all pumps, electrics, engine or steerage. These second level windows may also provide key information about and/or control of the relevant subsystems,

such as a summary status . Each second level window provides access to further windows 194 providing more specific control or information relating to particular components of each subsystem, such as particular pumps, generators and so forth.

It has already been discussed, in connection with figure 6, that the HMI process 148 implements a system of access rights controlling the extent to which particular terminals or users of the system can control the machine components, alarms, network and the control system itself, using a set of access parameters 151 to which the HMI process 148 has access. In the present example, to initiate the operation of a terminal 116 it is necessary to input a user name and a password, although a password may not be required for certain user names. Different user names are associated with different levels in a user hierarchy as illustrated in figure 9. At a top "supervisor" level 200, users have full access to all functionality of the control system, including both operational control of all machine components through the various user interface windows, and system administration control of aspects of the control system itself such as the operation of the control servers, network elements and so forth. At a lower "senior" level 202, users have full access to all machine components through the user interface windows, but do not have any access to system administration control functions.

At a yet lower "operational" level 204, users have no system administration control, and only limited control of machine components. At this level, users may have restricted access to particular user interface screens, certain user interface screens may omit certain functional control elements, or certain control elements may be displayed but

disabled. For example, one "operational" user may be restricted to control of engine room functions, while another may be restricted to control of electrical functions . Conveniently, control access to machine components may be delimited according to the pages of the user interface which were discussed above in connection with figure 8, so that a particular operational user may be given access to any functionality only on certain of the user interface pages, which are designed accordingly.

At a yet lower "display" level 206, one or more display users may be defined. A single display user name could be defined which provides full display-only access on any terminal activated using that user name. Alternatively, multiple display users could be defined, optionally with display access to limited parts of the control user interface. For display users, the requirement to enter a password could be waived.

For safety and operational purposes, preferably only one user has control of any particular element or group of elements of the machine components at any one time. Therefore, to allow a user at a higher level of the user hierarchy to be logged on to one terminal at the same time as a user at a lower level is logged on to another terminal, it may be necessary to suspend the access of the higher level user to control functions available to the lower level user. This restriction can be implemented by limiting operational use of any one interface page to a single user at any one time. However, a higher level user is given the ability to wrest control of functions from a lower level user.

Referring now to figure 10, the functionality of a user terminals 116 may be integrated into other terminal equipment on board the vessel . This is especially possible because of the thin client nature of the control system terminals 116 which require only appropriate graphics client software, such as an XIl client or an HTML browser.

Figure 10 illustrates a marine radar system including a radar antenna 210 which is controlled by and returns radar signal data back to a radar processor/controller unit 212. Conventionally, the processor/controller 212 would provide a video feed to a dedicated display/control unit to display the radar data and with limited functionality to return control signals to the processor/controller. However, in the present embodiment the display/control unit is replaced with a radar/control computer 214 provided as a marine approved personal computer with appropriate peripherals such as a screen 216 and keyboard 218, and executing a radar graphical user interface (GUI) 220.

The radar/control computer 214 also executes a graphical client such as an XIl client process 222 which receives a graphics feed over the network 100. The radar/control computer 214 is configured to allow a user to switch the display between a radar user interface and a control system user interface, or to allow windows from both interfaces to be displayed at the same time.

Figure 11 illustrates two different user interfaces or user interface windows displayed by the radar/control computer 214. A radar interface 230 provides radar data display 232 and controls 234 and a system control interface switch 236. Operation of the system control switch 236 activates a system control interface 240 and deactivates the radar interface 230.

The system control interface 240 comprises access to part or all of the human machine interface provided by the HMI process 148 of the control server 110 as discussed above, but also provides a radar interface switch 242. Operation of the radar interface switch 242 activates the radar interface 230 and deactivates the system control interface 240.

It will be apparent to the skilled person that a variety of alternatives and modifications to the embodiments described without departing from the spirit and scope of the invention.