GB2287163A

GB2287163A - Identification of prohibited articles contained in luggage

Info

Publication number: GB2287163A
Application number: GB9504036A
Authority: GB
Inventors: Georg Geus; Patricia Schall; Hermann Ries
Original assignee: Heimann Systems GmbH; Heimann Systems GmbH and Co KG
Current assignee: Heimann Systems GmbH; Heimann Systems GmbH and Co KG
Priority date: 1994-03-03
Filing date: 1995-02-28
Publication date: 1995-09-06
Anticipated expiration: 2015-02-28
Also published as: DE4406956A1; GB9504036D0; DE4406956C2; GB2287163B

Description

2287163 1 - T ITLE Method of Testing Prohibited Objects in Luggage This

invention relates to a method for testing and detecting prohibited objects in luggage by means of a multistage detector system.

The monitoring of objects, and particularly luggage which is to be taken on board an aircraft, for the possible presence of explosives or bombs, is an essential requirement for the safety of air transport. The corresponding detection devices are on the one hand required to operate with high precision, in order to ensure maximum detection efficiency combined with a very low false alarm rate and on the other hand have to ensure a high rate of throughput in order to process the large number of objects to be monitored in the time available.

Detection devices operating by the known methods are therefore usually formed from two or more stages, the first of which generally consists of a rapid system capable of coping with the recurrence rate of the objects, combined with a high explosive detection probability rate. This system suffers from an excessively high false alarm rate in relation to the relevant testing requirement. In the subsequent stage 2 or stages the continually decreasing number of objects which have activated an alarm, or a false alarm, are examined in more detail over a longer time. Known multistage apparatus operating by the method referred to examine again the complete object in the second or later stage. This process takes valuable measuring time which may be required for highly accurate verification of material at some other point. One of the objects of this invention, in contrast to the foregoing, is to concentrate the examination process in the second or higher stage on those parts of an object wherein an unambiguous view was not obtained in the previous stage and to thus speed up the entire process in the said second or higher stage. According to this invention there is provided a method of testing for detecting prohibited objects in luggage, said method using a multistage detector system, wherein a) in a lower stage of the detector system an object to be tested is notionally subdivided into a twodimensional system of coordinates at least and the positions of any areas of the object containing suspect articles and in which clarity is not obtained are defined by the coordinates; b) in a subsequent step in the method the coordinate - 3 values are transferred to at least one higher stage of the detector system; c) in the higher stage an exclusively local examination is effected, in the zone defined by the coordinates of the said object in order to achieve better clarity. This invention therefore is based on the realisation that at the lower stage of the method the material to be monitored is subdivided at least into a two-dimensional system of coordinates by the aid of which certain positions in the material are unambiguously described and transmitted as coordinates to the higher stage. In the higher stage of the method either the material or the measuring apparatus is adjusted according to the said coordinates, only local examinations being then carried out on the items, of luggage for example, and of which the nature was not completely clarified initially. This method thus also enables locally detailed special measurements to be effected over a longer time period if necessary. A further advantage of the precise localisation resides in the reduction in damage which the material is liable to suffer, for example photographic films in a passenger's luggage may be subjected to damage by ionising radiation, this being because objects outside the examination zone remain unaffected.

The method of this invention is further described and in greater detail and by way of example with reference to the diagram shown in the drawing.

In the drawing an object 16 to be examined by a detection system consists of a suitcase passing through the first stage of a customary security screening scanning apparatus on a conveyor belt, not shown, in the direction indicated by the arrow 28. The tests performed in this lower stage of the detection system are already known and are described, for example, in EP 0390950 Bl or in DE 4137372 Al.

On the introduction of the object 16 into the lower stage 14 of the method at least two-dimensional coordinates 20, 22 are defined. With a two-dimensional coordinate system 18 the coordinate points 20 lie in the Y direction and the coordinate points 22 lie in the X direction for example. With a three-dimensional system of representation a further coordinate, not shown, would extend perpendicularly to the coordinates 20, 22 in a Z direction.

The definition of the coordinates in the lower stage 14 of the process can be effected in various ways. In one variant of this invention it is possible, in the lower stage 14 of the method, for the coordinates to be defined, according to the object, by the leading edge 26 - of the object 16, this edge being recognised by light beams (not shown). A further variant enables the coordinates 20, 22 to be defined in accordance with the transport means, for example by the aid of certain marks on the transport means, which are not shown in the drawing, and according to which the object 16 is aligned. By means of stepping motors, position sensors or comparable devices, not indicated, the coordinates 20, 22, continue to be counted during the examination process, for example as the transport of the object continues within the lower stage of the method, the scale being adapted to the degree of accuracy determined by the measuring process.

If the measuring process detects in the monitored object 16 a point to be re-examined, for example one or more articles of luggage 10 on which complete clarity has not yet been obtained, the present coordinates, which may, for example be between X2 and X, and between Y2 and Y1, arei read and transferred, if necessary, to the higher stage 24 in the method through an intermediate store (not shown). The monitored object is then conveyed, for example, by means of a conveyor belt (not shown) to the higher stage 24, moving in the direction-indicated by the arrow 30.

This higher process stage 24 evaluates the coordinate details determined in the lower stage and aligns the object 16 or the measuring system accordingly. A local examination is then effected of the particular position of any article of luggage 10 which may have proved unacceptable or even of a number of positions thus marked. In the higher process stage the article of luggage 10 can be examined by any testing methods possibly differing from the lower process stage, for example using X-ray diffraction techniques or by nuclear or particle radiation methods, such as neutron activation (excitation) analysis.

The coordinates transferred from the lower to the higher process stage takes place under computer control using microprocessors (not shown) via a cable connection 32, for example, or an optical conductor.

If no unacceptable article 10 is detected in the object 16, then this leaves the detection system in the direction shown by the arrow 34 immediately after passing through the process stage 14, so that the higher process stage is not employed.

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Claims

1. Method of testing for detecting prohibited objects in luggage, said method using a multistage detector system, wherein a) in a lower stage of the detector system an object to be tested is notionally subdivided into a twodimensional system of coordinates at least and the positions of any areas of the object containing suspect articles and in which clarity is not obtained are defined by the coordinates; b) in a subsequent step in the method the coordinate values are transferred to at least one higher stage of the detector system; c) in the higher stage an exclusively local examination is effected, in the zone defined by the coordinates of the said object in order to achieve better clarity.

2. Method of testing in accordance with Claim 1, wherein the coordinates, on the introduction of the object in the lower stage, are referenced relative to the object.

3. Method of testing in accordance with Claim 2, wherein the coordinates are defined by reference to a front edge of the object, the said edge being recognised by a detector such as a light beam.

4. Method of testing in accordance with Claim 1, wherein the coordinates, on the introduction of the object in the lower stage, are defined by reference to a transport means, using indices in or on the said transport means and by which the object is aligned.

5. Method of testing in accordance with any one of Claims 1 to 4, wherein the coordinates determined in the lower stage are transferred to the higher stage through an intermediate store.

6. Method of testing in accordance with any one of Claims 1 to 5, wherein at least two different monitoring operations are carried out in the lower stage and in the higher stage.

7. Method of testing passengers' luggage or the like objects carried out substantially as described herein and exemplified with reference to the drawings.

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8. Security screening apparatus constructed and operating in accordance with the method of any preceding claim.