GB2332547A

GB2332547A - Radio tagging security systems

Info

Publication number: GB2332547A
Application number: GB9726853A
Authority: GB
Inventors: David Richard Norrie
Original assignee: Oxley Developments Co Ltd
Current assignee: Oxley Developments Co Ltd
Priority date: 1997-12-20
Filing date: 1997-12-20
Publication date: 1999-06-23
Anticipated expiration: 2017-12-20
Also published as: GB2332547A9; GB2332547B; GB9726853D0

Abstract

A security system based on tagging is disclosed. Items to be monitored are provided with respective RFID transponders/tags in a first class 2 which are such as to be activated when brought into the vicinity of an antenna 5 coupled to a decoder 6 by which an alarm or other suitable response can be raised. Thus for example, the system can be used in a hospital to give an alarm signal if an infant is taken from a secure area. However, the system includes transponders/tags in a second class 4 and the decoder 6 is programmed not to raise the response (eg. the alarm) if within a period after detecting a transponder of the first class it detects a transponder of the second class. Hence the response can be inhibited, eg. by a tag worn by an authorised person. Transponders associated with different types of item may have respective different response times.

Description

2332547

-1DESCRIPTION

IMPROVEMENTS IN RADIO TAGGING SECURITY SYSTEMS The present invention is concerned with security systems which involve radio tagging of articles, objects and other items whose location and/or movement is to be monitored.

Such systems constitute forms of Electronic Article Surveillance (EAS) using Radio Frequency Identification (RFID).

One known system, where radio tagging is employed to monitor location/movement of items within/from a supervised area, is concerned with the monitoring of baby location/movement within a hospital environment. In the current system, a nurse uses a swipe card (or equivalent) to inform a security system prior to taking an infant out of a secure area. An alarm system, which detects an RF tag on the infant, is arranged to be de-activated for a short period after the nurse has identified herself. This is necessary because the current RFID system cannot reliably identify multiple RF tags. In the absence of the nurse identifying herself within that short period, the alarm would be activated.

Such systems are therefore awkward and time consuming in that the nurse needs to carry a special swipe card (or the equivalent) and have a hand free to perform the swiping operation.

Tag systems are now becoming available, however, which can identify multiple tags and it is an object of the present invention to make use of the latter tag systems to overcome some of the drawbacks of existing security apparatus.

According to a first aspect of the present invention, there is provided a security system wherein assets to be monitored are provided with respective RFID transponders/tags of a first class which are adapted to be activated when brought into the vicinity of an antenna coupled to a decoder by which an alarm or other appropriate response may be raised, the decoder being programmed such that if, within a predetermined period before or after detecting an asset transponder, it detects the presence of an RFID transponder of a second class associated with an authorisation for these assets to be moved or relocated, the alarm or other appropriate response is not raised.

Thus, the alarm or other appropriate response is arranged to be suppressed by the detection of the combination of signals, within the predetermined period, from an asset transponder of said first class and a transponder of the second class associated with the necessary authorisation, for example carried by an authorised person.

Thus, for example, if the asset is a baby and the authorised person is a particular nurse, then the raising of the alarm or other appropriate response will be suppressed by the detection of the presence, within the predetermined period of the combination of the baby and that nurse. Obviously, several nurses, doctors etc. could be "authorised persons" and carry suitable transponders. Likewise, there could be a number of babies being supervised.

In an industrial situation, the assets could for example be manufactured items and the authorised person someone who is authorised to transport such items out of the secure/monitored area.

Different categories of items to be monitored can be identified by arranging for the transponders associated with said different classes or categories to respond at different rates detectable by the decoder. This can enable, for example, the presence of an authorised person to be detected quickly, regardless of the overall size of the population of individual item transducers.

Thus, according to a second aspect of the present invention, there is provided a system wherein items of different types are to be monitored, in which respective different classes of transponder are associated with different types of items such that the response times of different classes of transponder are programmed to be of different speeds so as to enable one particular class Z:1 of transponder to be capable of being recognised by a detector coupled to an antenna regardless of the size of the total population of items/transponders that Z may be within the range of the antenna.

Where the invention is applied to warehouse security and tracking, the presence of an authorised storekeeper can be detected to enable goods to be released and dispatched.

There may also be situations where there is a hierarchy of transponders, for example on individual items, boxes/crates pallets and containers, as well as on personnel. Advantageously the system is adapted to identify the "highest level" transponder first. This can be achieved by arranging for each tag to respond at random intervals to avoid contention. The range of the random delay intervals can be programmed for different classes of tags, thus enabling higher level tags to be read earlier in the sequence without, for example, having to resolve several hundred tags in order to identify their security status.

The invention is described further hereinafter, by way of example only, with reference to the accompanying drawings, in which:- Figures 1 and 2 illustrate diagrammatically two different embodiments of asset monitoring systems in accordance with the present invention.

Referring first to Figure 1, there is illustrated a system wherein items such as assets 1 are to be monitored and an alarm or other appropriate response raised if an attempt is made to remove them from the monitored area without approved authorization. At the or each outlet of the monitored area, there is provided an antenna 5 coupled to a decoder/computer 6. Also connected to the decoder/computer 6 is an alarm system, including for example an alarm bell/siren 7.

Attached to each asset item 1 is an RED transponder 2. A further RED transponder 4 is carried by the or each person 3 who is authorised to remove assets 1 from the monitored area.

The transponders 2, 4 are such that when they approach or are in the vicinity of the antenna 5 they are energised/activated to transmit a respective signal which is picked up by the antenna and transmitted to the decoder/computer 6. The decoder/computer 6 is programmed such that if it detects the presence of the or any transponder 4 associated with an authorised person, within a predetermined set period of time before or after detecting the presence of the asset transponder 2, the alarm which would otherwise be raised when the presence of an asset transponder 2 is detected, is suppressed.

Thus, the alarm is suppressed by the detection of the combination of signals, within a predetermined period, from an asset transponder 2 and a transponder 4 associated with an authorised person.

Referring now to Figure. 2, there is illustrated a development of the system of Figure. 1 which uses an antenna 12 and a decoder/computer 13. In this embodiment, there are a number of different classes of assets, for example individual items 7, boxes 9, pallets 8 and personnel 10. All of these are fitted with RFID transponders 11 which are activated and detected by the antenna 12 and the decoder system 13.

It is arranged that the transponder(s) associated with the authorised person(s) have on average a faster response time to the activation signal provided via the antenna 12 than that of the transponder associated with the individual items 7 and boxes 9. By this means, the decoder system 12 can easily identify quickly the presence of the authorised person 10 regardless of the size of the population of individual item transponders present.

By utilising a similar arrangement, it is also possible to enable pallet transponders 8 to be preferentially identified in the presence of many box transponders, and likewise box transponders to be preferentially identified in relation to individual items.

Using such an arrangement, the presence of one class of transponder can be used to control the system response to the presence of a second class of transponder.

Furthermore particular transponders can be programmed to respond more frequently in order to be recognised in the presence of many other transponders operating within the same RF system.

Still further, the system can be extended to situations where there is a hierarchy of tags/transponders on items, boxes/crates, pallets and containers etc. as well as on personnel. If many hundreds of tags/transponders are present it is clearly highly advantageous to identify the "highest leveP of tag first.

A further application of the techniques of the present invention lies in hospital baby tagging systems. Authorised nurses (or mothers) and supervised babies all carry transponders. The system software in the decoder/computer is programmed to verify their individual identities and to allow only approved combinations to pass from a supervised area. Thus, for example, the system will generate an alarm if a baby transducer is detected without an authorised nurse/mother transponder within the specified predetermined period.

The latter system has the great benefit of a completely hands-free operation and simplified hardware compared to existing systems wherein, because current RFID systems cannot reliably identify multiple RF tags/transponders, nurses have to use a swipe card (or equivalent) to inform the surveillance system prior to taking the infant out of the secure area, and wherein the alarm system which detects an RF tag on the infant, is deactivated for a short period after the nurse has identified herself.

Claims

1. A security system wherein assets to be monitored are provided with respective RFID transponders/tags of a first class which are adapted to be activated when brought into the vicinity of an antenna coupled to a decoder by which an alarm or other appropriate response may be raised, the decoder being programmed such that if, within a predetermined period before or after detecting an asset transponder, it detects the presence of an RFID Under of a second class associated with an authorisation for these assets to be moved or relocated, the alarm or other appropriate response is not raised.

2. A security system as claimed in claim 1, wherein transponders of the second class are such as to respond more rapidly andlor more frequently thm responders of the first class.

3. A security system as claimed in claim 1 wherein the transponders are arranged to respond at random intervals, selected transponders being arranged to respond more frequently than others, whereby these transponders can be detected more rapidly than others.

4. A security system as claimed in claim 3, wherein transponders in the second class are arranged to respond more frequently than transponders in the first class.

5. A security system as claimed in any preceding claims having a hierarchy of transponders, the system being adapted to detect the highest level transponders first.

6. A system for monitoring items of different types, in which -8respective different classes of transponder are associated with different types of item different classes of transponder being programmed to have different response times so as to enable one particular class of ponder to be capable of being recognised by a detector coupled to an antenna regardless of the size of the total population of items/transponders that may be within the range of the antenna.

7. A system as claimed in clahn 6, wherein there is a hierarchy of transponders and the system is adapted to identify the highest level transponders more rapidly than others.

8. A system as claimed in claim 6 or claim 7 wherein the transponders are arranged to respond at random intervals, the average interval being shorter for the one particular class of transponder than for others.

9. A security system substantially as herein described with reference to, and as illustrated in, the accompanying drawings.