GB2191624A - Simulating inspection (e.g. ultrasonic) equipment - Google Patents

Abstract

Apparatus for simulating inspection equipment, eg. ultrasonic non-destructive testing equipment or ultrasonic medical diagnostics equipment, comprises a simulated test body (16) (i.e. a test body which does not actually incorporate inspectable features, e.g. defects), a simulated probe (18) for operator-controlled scanning over the body, a probe position monitor (20), storage (12, 14) for pre-recorded inspection data, a display (22) and a central processor (10) for correlating display of the inspection data with scanning movement of the probe (18). The inspection data may be derived from non-simulated scanning of for example a structure containing defects and the ultrasonic waveforms obtained during such non-simulated scanning provide a realistic display during simulated scanning of the test body (16). The need for test bodies actually incorporating defects is thus avoided. <IMAGE>

Description

SPECIFICATION Apparatus for simulating inspection equipment This invention relates to apparatus for simulating inspection equipment, eg for the purpose oftraining personnel in non-destructive testing (NDT) techniques such as ultrasonic inspection or medical diagnostics using ultrasonic techniques.

At present, NDTtraining is carried out with the aid oftest blocks having aritifically implanted defects and NDTtrainees carry out scanning, eg with a conventional ultrasonic probe which may be operated manually or automatically. This suffers from a number of drawbacks in that: such test blocks are expensive to produce and tend to be relatively immobile so that trainees haveto attend wherever the test block happens to be located; additional test blocks may need to be produced in order to offer a reasonably wide range of training experience; the security ofthe test block may be compromised in the sense that details of defects and locations may be passed to trainees in advance of a testing session; and only defects capable of being manufactured can be impianted.

One object ofthe present invention is to provide apparatus for simulating NDT equipment which avoids the use of test blocks with artificially implanted defects.

According to the present invention there is provided apparatus for simulating inspection equipment comprising a simulated test body, a simulated transducer which can bescanned manually or automatically under the control of an operator over said simulated body, means for monitoring the position co-ordinates ofthe simulatedtransducerduring such scanning, means for digitally storing pre-recorded inspection data and positional information obtained in the course of non-simulated scanning of a non-simulated body, and means responsive to said monitoring means for retrieving from said storing means inspection data corresponding to the positional co-ordinates ofthe simulated transducer whereby scanning ofthe simulated transducer over the simulated body is accompanied bythe production of inspection data correlated with the scanning movement.

The retrieved inspection data may be transferred to display meansforviewing by an operator.

In this manner, in the case of NDT inspection the operator is given the impression of carrying out a realtime NDTexamination of a substantial defect-containing structure even though in reality the simulated test body may merely consist ofthin stainless steel plate material which may be fabricated to give the appearance of a substantial structure.

In an alternative application, the retrieved inspection data may be fed to data gathering equipment.

The simulated transducer may resemble, or be constituted by, a conventional transducer (eg an ultrasonic transducer) althbugh it will be understood that where a n actual transducer is em ployed it will not be operational in the conventional sense but will merely be provided to give the operator a realistic impression of performing an inspection.

In one embodiment of the invention, the monitoring means may include a digitising tablet as used in for example computer aided draughting, the digitising tablet being incorporated in the simulated test block, for example underneath the stainless steel plate described above. The simulated transducer in this event may include an electrical coil inductively coupled through the stainless steel plate to the digitising tablet and the latter may provide an output representing the coil position in XY co-ordinates.

The pre-recorded inspection data is conveniently stored in a non-volatile memory, such as a magnetic disc or tape, and the apparatus may include volatile memory, such as semi-conductor random access memory, which is loaded with the inspection data corresponding to a range of positions around the "instantaneous" position ofthe simulated transducer and is updated in responseto each new position of the simulated transducer registered by the monitoring means. Transfer ofthe inspection data from the volatile memory to the display means or data gathering equipment may be effected by a central processor and the monitoring means may be constituted by a peripheral processor so thattime delays in determining the "instantaneous" position ofthe simulated transducer can be minimised.

To promote further understanding ofthe invention an embodiment will now be described by way of example only with reference to the accompanying drawing the sole Figure of which is a schematic block diagram.

As shown, the system for simulating for example ultrasonic non-destructive testing comprises a mini-computer 10 coupled with a disc drive 12 and buffer storage 14. The disc drive 12 is loaded with a disc containing all the software forthe system together with ultrasonic defect data. The defect data istransferablefrom the disc to the buffer storage 14 for rapid access by the mini-computer, as explained below.

The defect data is derived from non-simulated NDT ultrasonic scanning of a specimen or specimens known to contain defects. The specimen(s) may be deliberately manufactured with implanted defects or may be a structure for which a "real-life" ultrasonic NDTexamination has been recorded. Typically, the defect data will consist of a large numberofdigitised ultrasonic waveforms and their corresponding position co-ordinates.

The test block is simulated by a stainless steel plate 16 beneath which a high resolution digitising tablet is located. The simulated transducer 18 is movable over the surface of the plate 16 and incorporates a coil inductively coupled with the digitising table so thatthe latter can provide an output in digital form representing the positional co-ordinates ofthe simulated transducer 18 at any instant. This output is monitored by a peripheral processor 20 and put into a form suitable for access within the software routines of the mini-computer 10. Since this is done independently of the mini-computer, no time delay occurs when the mini-computer requests data relating to the position ofthe simulated transducers.

During scanning of the simulated test block, the mini-computer 10 as part of its program cycle repeatedly interrogates the peripheral processor to obtain the current positional data for the simulated transducer 10 and, using that data, then retrieves from the corresponding ultrasonic waveform either directly from the buffer storage 14 if already available or from the disc viva the buffer storage.The digitised waveform data is transferred to a display 22, such as an oscilloscope, via a function generator 24 which converts the digitised data into analogue form to provide a reconstructed waveform on the display which may be indistinguishable from the waveform that an operator would expect to see on observing an actual defect embedded in a steel test block or, on-site, in a manufactured item such as a pressure vessel.

The mini-computer 10 is programmed so that, on obtaining positional data from the peripheral processor 20, the buffer storage 14 is loaded with the waveform corresponding to that particular positional data (if not already available in the buffer storage) and also the waveforms corresponding to a limited range of positions surrounding the current position of the simulated transducer 18. In this way, the waveform data for subsequently displacement of the simulated transducer within that limited range is immediately available from the buffer storage thereby avoiding delay in reading waveform data from disc to the buffer storage.Even when the buffer storage 14 already contains the required waveform data for a new position ofthe transducer, the buffer storage may be updated with waveform data corresponding to a predetermined range of positions centred on the new position.

From the foregoing it will be seen that the system as described aboveaffordsthefollowing advantages: a. Real data from real flaws is used to generate the waveforms presented to the inspection equipment and/or inspector. These can come from: 1. Deliberately introduced defects in test blocks.

2. Real defects that may exist due to manufacturing in the type of structure to be encountered by test personnel.

3. Predicted defects that cannot yet be artificially manufactured, but are known to be possible. It is envisaged that theoretical modelling work could supply the data such thatthese defects may be experienced by inspectors ortheirtest equipment before they are encountered in practice.

b. The data is repeatable and accurate since the waveforms are recalled from memory without distortion or degradation. The data may be copied or transmitted to other test facilities where simulator systems exist. No differences will exist between the data presented to inspectors and test equipment in the various locations and therefore comparisons and standards will be maintained over large distances in dispersed training and validation sites.

c. The system is quickly disassembled for transportto other locations, and the waveform data may be transmitted over electronic links between sites and countries. This is notthe case at present with very large test blocks.

d. The system is cheaperthan using test blocks and can take the place of many test blocks since it is so easiiy re-configured.

e. The security of the system relies upon the fact that an inspector cannot know from one session to another where the simulator programmer has placed a defect, either in orientation, position, depth orwhattype it is. This is not the case with test blocks, since if the location of defects are known or passed on to third parties the security ofthattest block is compromised.

Although the invention is described above in relation to NDT of defect-containing structures, the invention also has application to medical inspection techniques using for example ultrasonics. In this instance, the test body may be contoured to simulate for example the trunk of a human body and a probe is used to scan over the simulated trunk, means being provided to monitorthe position of the probe (eg. in 3 dimensions). In this case, pre-recorded inspection data obtained from ultrasonic inspection of a living human body may be stored digitally by means of a laser-readable optical disc and the stored data may be retrieved in dependence upon the "instantaneous" position of the probe relative to the simulated trunk and processed to produce a C-scan display which will change as a probe moves across the trunk. The optical disc may be used in conjunction with volatile memory so that at any instant the memory is loaded with inspection data associated with the current position of the probe and, in addition, data associated with a range of positions lying within a zone around the current probe position.

Claims (4)

1. Apparatus for simulating inspection equipment comprising a simulated test body, a simulated transducer which can be scanned manually or automatically under the control of an operator over said simulated body, means for monitoring the position co-ordinates ofthe simulatedtransducerduring such scanning, means for digitally storing pre-recorded inspection data and positional information obtained in the course of non-simulated scanning of a non-simulated body, and means responsive to said monitoring means for retrieving from said storing means inspection data corresponding to the positional co-ordinates of the simulated transducer whereby scanning of the simulated transducer over the simulated body is accompanied bythe production of inspection data correlated with the scanning movement.

2. Apparatus as claimed in Claim 1 including means for displaying the inspection data as a visual image.

3. Apparatus as claimed in Claim 1 or 2 in which said digital storing means comprises a non-volatile memory.

4. Apparatus as claimed in Claim 2 or3 in which a central processor effects transfer of data from the volatile memory to the display means or data gathering equipment and the monitoring means is constituted bya peripheral processor.

4. Apparatus as claimed in Claim 3 including volatile memory and means for selectively effecting loadingthevolatilememorywith partofthe inspection data from the non-volatile memory in dependence upon the instantaneous position ofthe simulated transducer.

5. Apparatus as claimed in Claim 4 in which said loading means is operable to effect loading of the volatile memory with inspection data associated with a range of positions around said instantaneous position.

6. Apparatus as claimed in Claim 4 or 5 in which a central processor effects transfer of data from the volatile memory to the display means or data gathering equipment and the monitoring is constituted by a peripheral processor.

7. Inspection apparatus substantially as hereinbefore described with reference to, and as shown in, the accompanying drawing.

Amendments to the claims have been filed, and have the following effect: (a) Claims 1,3,4 and 6 above have been deleted or textually amended.

(b) New ortextually amended claims have been filed as follows: (c) Claims 5 and 7 above have been re-numbered as3and5.

1. Apparatus for simulating inspection equipment comprising a simulated test body, a simulated transducer which can be scanned manually or automatically underthe control of an operator over said simulated body, meansfor monitoring the position co-ordinates ofthe simulated transducer during such scanning, storing means comprising non-volatile memory for digitally storing pre-recorded inspection data and positional information obtained in the course of non-simulated scanning of a non-simulated body, means for selectively effecting loading of a volatile memory with part of the inspection data from the non-volatile memory in dependence upon the instantaneous position ofthe simulated transducer, and means responsiveto said monitoring means for retrieving from said volatile memory inspection data corresponding to the positional co-ordinates ofthe simulated transducerwhereby scanning ofthe simulated transducer overthe simulated body is accompanied by the production of inspection data correlated with the scanning movement.