GB2233120A - Computer-aided design equipment - Google Patents

Abstract

Computer-aided design equipment for designing a control system for an installation incorporating detector devices, has a visual display device 1, 6, user controls 4, 5, a data storage device 3 and a processing device 2. The processing device 2 operates to produce one or more displays on the visual display device 1, 6, from which a user can select particular interrelationships of input and output signals of the detector devices by use of one or more of the user controls 4, 5. The processing device 2 also operates to produce a further display which is representative of a chart and on which there are lists of the input and output signals of the detector devices along with indicators which are representative of the selected interrelationships between the signals. Application is to a safety system, where the inputs are smoke detectors, gas sensors, etc and the outputs are alarms, sprinklers, valves, etc. The stored data may be used directly for control purposes. <IMAGE>

Description

COMPUTER-AIDED DESIGN EQUIPMENT This invention relates to computer-aided design equipment.

In hazardous industrial installations, such as off-shore oil platforms, it is known to use automatic safety systems to provide protection against fire, gas leakage etc., such sytems comprising sensors, such as smoke detectors, gas detectors, etc., and protective devices such as alarms, sprinklers, shut off valves, etc., interconnected by a computerised control system. The protective devices are automatically actuated in a predetermined manner depending on inputs received from the sensors.

Thus, for example, where a single smoke detector is activated by detection of smoke the arrangement may be such that an audible alarm is operated by the control system whereas, where multiple smoke detectors are activated a sprinkler may be operated.

With this known arrangement, to set up the system it is necessary to identify the various sensors and protective devices and to design the desired control relationship therebetween, and commonly this is done with the assistance of a printed cause and effect chart having lists of input signals and output signals respectively along mutually perpendicular axes. Marks are made on the chart at intersections between related input and output signals so that, for example, it can be readily seen what inputs are required to activate or cause any particular output to be operated. The resulting chart is then used as a basis for assessing the correctness of the specified responses and as a basis for configuring the control system.Where a computerised control system is to be used the chart may be used as a basis for the preparation of the control programs for the system, this is commonly performed using the so-called ladder logic method which provides a pictorial representation of the system logic.

This known arrangement requires setting up, filling in and assessment of a chart for each area or zone of the installation which may be time consuming, tedious and error prone especially for large installations. Moreover, the known arrangement has practical limitations with regard to versatility and flexibility having regard to the inconvenience of repeatedly modifying charts and of producing charts which permit overall control of an installation as distinct from the detail control of the individual zones within the installation.

An object of the present invention is to provide computer-aided design equipment with which charts representing a desired relationship between input and output signals can be produced in a simple, convenient and versatile manner.

According to the invention therefore there is provided computer-aided design equipment for use in designing a control system for an installation incorporating detector devices, said equipment comprising a visual display device, user controls, a data storage device, and a processing device, said processing device being arranged to produce on said visual display device at least one display representing selectable interrelationships of input and output parameters of said detector devices, said user controls being operable to effect selection of said selectable interrelationships, and said processing device being further operable to produce at least one display representative of a chart having at least one list of input parameters of said detector devices, at least one list of output parameters of said detector devices and a matrix of discreet areas related to said lists, with indications in said areas representative of said selected interrelationships.

With this arrangement a chart representing design parameters of a control system can be produced in a particularly simple and convenient manner, furthermore, since the chart is produced automatically, there is considerable potential for flexibility and versatility in that new charts can be readily produced when required to accommodate changes in selected parameters. Also, there is the possibility of providing for the production of different charts derived from the same selected parameters e.g. charts. relating to selected portions or the whole of the control system as required.

The produced chart may be in the form of a display on the visual display device or as printed hard copy or both.

The simplicity and convenience of the production of said charts is enhanced by exploiting a fundamental characteristic of the set of charts used to represent the design parameters of the safety system for an entire installation. The said characteristic is that if all the said charts for the installation are compared, it can be found that they are all approximate subsets of a theoretical master chart.

The invention can exploit this characteristic by allowing the explicit definition of said theoretical master chart. From this explicit definition the said cause and effect charts may be generated by selecting a subset of said input signals and said output signals from said explicit master chart, which results in the automatic inclusion of those marks that occur, on said explicit master chart, at the intersections between the selected input signals and the selected output signals.

When a change in the philosophy of the safety system results in a set of changes to said cause and effect charts that could be described by a change to said theoretical master chart then by. applying said change to said explicit master chart the required set of changes can be automatically made to said cause and effect charts.

In addition to providing at least one display representing selectable relationships between detector devices, there may be provided at least one display representing selectable parameters of the detector devices whereby for example different inputs can be selected for a particular device dependent on the requirements for actuation of the device within the control system.

The invention will now be described further by way of example only and with reference to the accompanying drawings of which: Fig. 1 is a block circuit diagram of one form of computer-aided design equipment according to the invention; and Figs. 2-10 show different VDU displays produced with the equipment.

As shown in Fig. 1 the computer-aided design equipment comprises a VDU 1, a central processing unit 2 of a microcomputer, a data storage device 3, a keyboard 4, a mouse 5 and a printer 6. For the sake of convenience the embodiment is described in relation to the use of a microcomputer but in practice a terminal-accessed mini or main frame may be used.

The VDU 1 comprises a conventional computer monitor with a high resolution colour screen.

The microcomputer is of a conventional kind and has an operating system which permits production of graphic and text displays on the VDU 1 and manipulation and storage of such displays.

The data storage device 3 has two parts: the internal memory of the computer (RAM and/or ROM) and external memory for example in the form of hard disc, floppy disc and solid state such as Electronically Erasable Programmable Read Only Memory (EEPROM) multiline board.

The keyboard 4 is a standard computer keyboard having usual functions, and the optional mouse 5 is a standard user control enabling the selection of individual pixels on the screen and identification of such by coordinate designation.

The printer 6 is a laser printer enabling high speed, accurate printing.

The VDU 1, processing unit 2, data storage device 3, keyboard 4, define a single computer system which may be formed as in integral unit physically, or as a number of separate interconnected units.

On logging into the system the user is shown a succession of types of screens from which he may select various parameters and combinations of parameters relating to a safety control system for a hazardous installation such as an off-shore oil platform.

The first type of screen, as shown in Fig. 2, relates to the classification of locations that the safety system is intended to protect.

This classification will be achieved by specifying the various hazards and associated safety equipment that may be used in any or all of the various locations.

Thus, as shown in Fig. 2, the screen allows the user to enter textual descriptions of the various items that will eventually allow for the classification of an area. This action will typically only take place once during the specification of a safety system, the result of this action is stored in memory and will be used both when printing charts and when entering data at later stages.

The data entered at this stage will appear on every cause and effect chart that is used in the specification of the system. An example of a possible location and style for this data is shown in Fig. 3 which is a specially prepared extract of an example cause and effect chart which could be produced from the same data as was used for Fig. 2.

The second type of screen, as shown in Fig. 4, relates to the explicit version of the theoretical master chart, and is used to enter all said input signals, all said output signals and the said interrelationship between them.

Thus, as shown in Fig. 4, the screen allows the user to enter textual descriptions of said input signals, said output signals and to mark said interrelationships between them. This action will typically only take place once during the specification of a safety system, the result of this action is stored in memory and will be used both when printing charts and when entering data at later stages.

The data entered at this stage will appear on every cause and effect chart that is used in the specification of the system. An example of a possible location and style for this data is shown in Fig. 5 which is a specially prepared extract of an example cause and effect chart which could be produced from the said data as was used for Fig. 4.

The third type of screen, as shown in Fig.6, relates to the definition of particular types of location that the safety system is intended to protect. This definition is achieved by selecting from among those various hazards and associated safety equipment, as described on the screen shown in Fig. 2, that are actually present at a location of the particular type.

Thus, as shown in Fig. 6, the screen allows the user to enter a selection against those relevant textual descriptions of said various items that allow for the classification of an area. This action results in the definition of a fire area type and will typically be repeated more than once during the specification of a safety system, once for each distinct type of fire area. The result of this action is stored in memory and will be used both when printing charts and when entering data at later stages.

The data entered at this stage will appear on those cause and effect charts that are used in the specification of fire area of this type within the system. An example of a possible location and style for this data is shown in Fig. 7 which is a specially prepared extract of an example cause and effect chart which could be produced from the same data as was used for Fig. 6.

The fourth type of screen, as shown in Fig. 8, relates to the explicit version of the theoretical master chart, and is used to select a set of said input signals, a set of said output signals and, implicitly, said interrelationships between them.

Thus, as shown in Fig. 8, the screen allows the user to select said input signal and said output signals. During the specification of a safety system this action will take place once for each definition of a type of fire area. The result of this action is stored in memory and will be used both when printing charts and when entering data at later stages.

The data entered at this stage will appear associated with the data entered with the corresponding fire area description. An example of a possible location and style for this data is shown in Fig. 9 which is a specially prepared extract of an example cause and effect chart which could be produced from the same data as was used for Fig. 8.

At the final stage a complete cause and effect chart for a fire area is produced by specifying its name and type. From this the correct cause and effect chart can be combined with the specified fire area definition chart to produce a final chart as shown in Fig. 10.

This chart can now be printed out by use of the printer or alternatively can be written onto a disc or other non-volatile storage device for subsequent display in the same or a different computer system.

Having produced the chart, it is now possible by use of the mouse to select parameters or areas from the chart and the computer will produce a display relevant to that parameter. Thus it is possible from the cause and effect chart for the whole system to produce one for each different area if desired.

It will be appreciated that the system is flexible insofar as it is possible to alter any of the inputs or outputs on the screens and the control system will be automatically redefined by the control device and a new chart will be produced for the new system.

It is to be understood that the invention is not intended to be restricted to the details of the above embodiment which are described by way of example only.

Thus, for example, a simple succession of four types of screen displays has been described but in practice there may be more types of screen displays relating to subdivision of the above described screens so that parts of the system can be considered, and parameters selected, in greater detail. Also there may be screen displays relating to auxiliary information, such as, for example, screen displays which show automatic actions (and which permit selection of parameters in relation thereto) in response to production of alarm-condition outputs. Essentially the system is capable of generating and displaying all the information required to enable the control system to be implemented as required. This information may be output, as described, in a form capable of being displayed on the VDU (or on a VDU of another computer system) or in printed form, such as a printed cause and effect chart. However, it is also possible for the system to provide an electronic output, as electronically stored data or as on-line or otherwise transmitted data which can be used directly in the control system thereby omitting wholly or in part the step of generating a computer program or computer data from a printed chart.

Claims (5)

1. Computer-aided design equipment for use in designing a control system for an installation incorporating detector devices, said equipment comprising a visual display device, user controls, a data storage device, and a processing device, said processing device being arranged to produce on said visual display device at least one display representing selectable interrelationships of input and output parameters of said detector devices, said user controls being operable to effect selection of said selectable interrelationships, and said processing device being further operable to produce at least one display representative of a chart having at least one list of input parameters of said detector devices, at least one list of output parameters of said detector devices and a matrix of discreet areas related to said lists, with indications in said areas representative of said selected interrelationships.

2. Equipment according to claim 1 wherein said produced chart is in the form of a display on the visual display device.

3. Equipment according to claim 1 or claim 2 wherein at least one further chart relating to a selected portion of the control system is derived from said selected parameters.

4. Equipment according to any one of claims 1 to 3 wherein at least one further display is provided representing selectable parameters of the detector devices whereby for example different inputs can be selected for a particular device dependent on the requirements for actuation of a device within the control system.

5. Equipment substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.