GB2382959A

GB2382959A - Asset protection system

Info

Publication number: GB2382959A
Application number: GB0223397A
Authority: GB
Inventors: Abolghasem Chizari
Original assignee: RADIOPLEX Ltd
Current assignee: RADIOPLEX Ltd
Priority date: 2001-10-09
Filing date: 2002-10-09
Publication date: 2003-06-11
Anticipated expiration: 2022-10-09
Also published as: GB0223397D0; GB2382959B; GB0124165D0

Abstract

An Asset Protection System for tracking the movement of assets 17 within a controlled area comprises a number of Monitoring Point units having a location identity transmitter 5, each located at a gate 18,19, 20, 21 defining an entrance to and exit from the area. Each transmitter 5 broadcasts its location into a small volume 4. Identification tags 6 are affixed to each asset 17 to be tracked. Each tag 6 includes sensor means 10, 9 to receive and recognize the location transmissions when within a transmitter's effective volume, and stores in sequence the location identities of the transmitters through whose gate it has passed. Each tag 6 is programmed with one or more sequences of location identities corresponding to permitted routes between the gate locations 18, 19, 20, 21. An alarm 14 is actuated if the asset 17 follows a path that deviates from its programmed route.

Description

ASSET PROTECTION SYSTEM Field of the Invention This invention relates to a method of, and apparatus for, protecting assets within commercial environments by detecting the movement of the assets through the environment and providing an alarm response in the event that the asset deviates from an authorised area or route through the environment. It concerns in particular, using signals for communicating to and from the assets which may be articles or personnel.

There are many situations in which articles or personnel have to be protected within a restricted area and as soon as an attempt is made to remove them, an alarm condition is created.

There are various types of radio frequency asset protection (RFAP) and identification (RFID) systems. Such systems operate by communicating to and from a tag, which is attached to or integrated into an asset within a restricted area. A restricted or radio fenced area is achieved by covering all the entrances & exits to that environment using a coded radio frequency transmission field. Whenever the tagged asset enters into the transmitting field of entry or exit point it starts to communicate. For example attaching the tag to an asset can protect the asset within a retail area and when an attempt is made to remove the asset from the retail area and it enters in to a specific transmitting field an alarm condition is created. However, there is a need for more effective and intelligent systems where assets can leave the restricted area under certain conditions without triggering alarm conditions or assets can be located and monitored within an area. These systems can be used for increasing efficiencies and improving profitability of asset management, processing and protection.

The available systems are generally categorised by the type of tags (transponders) used in the system that are either active or passive. Active tags are powered by an internal battery, have a longer read range of operation and are expensive. Passive tags operate without a separate external power source and obtain operating power generated from the reader. Therefore, they have a shorter reader range than active tags and also require a higher-powered reader. RFAP systems are distinguished by their frequency of operation. These systems commonly have operating frequencies as low as 30KHz and as high as UHF & Microwave frequencies.

Generally low frequency systems use magnetic fields to communicate and operate in the near field of the transmitting antenna. These systems use coils as the transmitting and receiving antennas, and are therefore usually large and result in entrance obstruction and are highly orientation dependent. For magnetic mode systems, the operating range is very short and is generally less then 0.5meters. Whereas high frequency systems operate in the far field and use electric fields to communicate and as the operating frequency increases the antenna structures for electrical field coupling start to become practical.

The majority of existing radio asset protection systems use lower operating frequencies and are based on passive tag technology with a short range of operation, unintelligent system, bulky system size which results in the blocking of entrances and possible health hazards due to a high level of emitted radio frequency power.

Summary of the Invention According to a first aspect of the invention there is provided an Asset Protection System for tracking the movement of assets within a controlled area and acting upon the movement tracked, comprising: a number of location-identity transmitters each located, at a gate defining an entrance to and exit from the areas, each transmitter being able to broadcast its location into a small volume there-around; a number of identification tags provided and affixed to each asset to be tracked; each tag including sensor means able to receive and recognize the location transmissions when within a transmitter's effective volume, and also having the ability to store information pertaining to the sequence of location identity transmitters through whose gate it has passed and also includes alarm means; in which each tag is programmable with one or more permitted routes for the asset to which it is affixed, between some or all of the gate locations for the defined area, and to activate the alarm if the asset follows a path that deviates from its programmed route.

According to a second aspect of the invention there is provided an Asset Protection method for tracking the movement of assets within a controlled area and acting upon the movement tracked, comprising the steps of:

positioning a number of Monitoring Point Units around the controlled area at gates defining entrances and exits from the area, each Monitoring Point Unit comprising a location-identity transmitter being able to broadcast its location into a small volume there-around, attaching a tag to the asset to be tracked, each tag including sensor means able to receive and recognize the location transmissions when within a transmitter's effective volume and also having the ability to store information pertaining to the sequence of Monitoring Point Units through whose gate it has passed and also including alarm means, transmitting data packages from each Monitoring Point Unit to a defined vicinity, pre-programming the tag to respond in a defined way to the series of signals received from Monitoring Point Units representing a route through the defined area.

This invention uses transmitting devices, which consist of a microcontroller, radio transmitter and a transmitting antenna. The transmitter device, which is called a Monitoring Point Unit (MPU), continuously transmits coded data packets which contain its address and will create a radiation field shape depending on the transmitting antenna used. These units are placed at the points of monitoring. For example they can be placed at entrances & exits to an area such as a retail store to achieve a radio fenced area.

The most important part of this invention is the tag, which is attached to assets or people, and preferably consists of antenna, a radio receiver, comparator, microcontroller and an audio warning device. There are microcontrollers with comparators on board such as ATtinyl2

microcontroller from ATMEL Corporation that can be used with ultra low power consumption.

The radio receiver is preferably designed in such a way that it does not require any battery power, and it is tuned to the operating frequency of the system-transmitting device. Therefore the tag has ultra low power consumption (ils) during its normal operating. For this reason it is referred to as a Semi-Active tag.

Monitoring Point Units transmit the data regarding each unit and depending on the antenna used, a coded radiation field is created which covers the entrance or exit points of the radio-fenced area or any other point of monitoring. Preferably, when an asset or people with Semi-active tags attached to them come within the range of a Monitoring Point Unit (MPU), it will wake-up the microcontroller and start to receive data. The microcontroller will be in sleep mode when it is not receiving any data.

Preferably the"wake up"of the tag is in two stages. In such case, when the tag passes within range of a Monitoring Point Unit, it will receive a voltage above a level (referred to as the trigger level) to place the tag in data receive mode. When valid data relating to the identity of the Monitoring Point Unit is received the tag is switched fully on to then activate the microprocessor and comparator to check the route being followed.

The software used on the tag will define the conditions and instructions depending on the present and past received data from coded transmitters, which are the monitoring point units. An alarm condition is created on the tag if the required conditions have not been met. These situations can be time dependent so that the alarm condition is created if the tag spends too

long in a certain zone or spends a longer period than it was programmed to outside a certain zone.

In one aspect, therefore, the invention provides a method of determining whether an article or person is leaving or entering or has permission to leave a radio fenced area without an alarm condition. The previous communication experiences (communication data) are stored to create a condition where the alarm is not triggered and can be used for analysing movement of assets and people within a radio fenced area.

Semi-active tag creating the audio alarm is more desirable then existing asset protection systems methods where gates emit an audio alarm, especially when large numbers of assets or people passing through the gate at any moment of time. The invention makes the task of locating which article or person have not met the required conditions much easier.

The alarm provided may comprise or include a visual alarm which will aid this location.

The preferred operating frequency for this system is in the UHF and microwave region of the frequency spectrum. The size of the required antenna would then be small enough to be implemented in to the Semiactive tag. It is possible to use a patch antenna for the transmitters to create a long and focused coded field to cover the point of monitoring.

Assets in this context extends to both articles and personnel and both are protected within a wide variety of environments ranging from retail, industrial, museums, hospitals, prisons or any other commercial sector. The small size of the tag means that it can be integrated seamlessly to many types of assets of widely varying sizes, from jewellery to vehicles. This is also true for protecting people as young as new-born babies or old age people within secure environments such as hospitals.

The tag's miniature size means that it can be integrated into small electronics devices and instead of creating an audible noise when an alarm condition is generated the tag can be used to do some other function that will render the device its attached to inoperable. Furthermore, this alarm condition can be time dependent so that if a tag is outside a certain zone for a given length of time then the alarm condition is generated. For example if a laptop meant to be rented for two days is out of the rental shop for more than this time period, the tag could internally disconnect the laptop's power rendering it unusable.

The tag is placed on the asset or people and has to be able to receive the data, when it enters a specific coded field. A radio frequency transmitter generates the coded field. This is referred to as a Gate Unit which is placed at the above the monitoring points.

An example of a monitoring point unit (MPU) could be using a microcontroller and a 2.45 GHz ON/OFF radio transmitter. The microcontroller is programmed so that it is continuously sending out a data packet which contains the address of the MPU and any other relevant information using an ON/OFF modulation technique. There are various antenna options at 2.45 GHz radio frequency, depending on the shape of the required coded field antenna can be selected. For example a patch antenna could be used to create a long narrow shape coded field. Therefore, the MPU will generate a radio frequency coded field, which contains coded information about the location and the address of the MPU.

The radio receiver used on the Semi-active tag has zero power consumption, hence it is in receiving mode at all times. The microcontroller and warning device will consume power and quiescent

current consumption of the Semi-active tag is in the order of a few u. A, therefore it has a long battery life.

For example a 2.45 GHz Semi-active tag could have a /4 length of wire or printed track on the printed circuit board (PCB) as the receiving antenna. The front-end filter could be printed as track on the PCB, which has inductance (L) and capacitance (C). A 2.45 GHz frequency detector is used to demodulate the data and a comparator used to produce a TTL output, which is fed to the microcontroller. The microcontroller is programmed so that it will be in sleep mode until it wakes-up with voltage received above trigger voltage and data input starting. If the received data packet is valid, it will register it and take action as required in the programme. The programme will set the conditions to be met if the alarm condition is not required. The simples system could have MPUs with two different addresses, one at the exit points with the same addresses and another at the point of authorisation with different address. The programme could behave in such a way that, tags which go to the point of authorisation and then go to the point of exits, will not create an alarm condition. If the tag goes to the exit point without going to the point of authorisation then the alarm condition is created.

At higher frequencies, it is easier to implement more efficient antennae for the radio transmitters and the receivers on the tag. Therefore lower emitted power is required to achieve the desired range of operation due to higher antenna efficiencies, hence it is a more environmentally friendly system.

The system is intelligent in such way that it can distinguish between assets or people that can and can not leave or enter the radio fenced area. An audio or visual warning is created on the asset or people, if they do

not have authorisation or do not met the required conditions to leave or enter the area.

The novelty of this invention is that, the tag attached to assets or people is self-contained with all the required parts to alarm condition. Therefore, it is much easier to locate a tag, which has not met the required conditions, when an alarm condition is created.

The invention thus provides asset and people protection with intelligence (read/write capability to carryout instructions), discretion (Small system size), a long range of operation, higher communication data rate, ultra low current consumption and a low tag cost.

Brief Description of the Drawings One specific embodiment of both aspects of the invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 shows transmitter and receiver radio frequency communication Figure 2 shows the radio frequency protection system set-up with the key as the asset.

Figure 3 shows a block diagram of the Monitoring Point Unit Figure 4 shows a typical radiation pattern of an antenna on the Gate Unit Figure 5 shows a block diagram of a Semi-Active Tag Figure 6 shows an intelligence flow diagram of the system

Description of the Preferred Embodiment Firstly referring to figure 1, a wireless radio communication link with a transmitter (1), propagating medium (2) and receiver (3) is shown. The range of operation of the system is defined by the valid data received from the transmitter. This range (4) is determined by the transmitted radiated power, the propagating medium and the receiver sensitivity.

The radio frequency protection system set-up is shown in figure 2, with the Monitoring Point Unit (MPU) transmitter (5), Semi-active tag (6) attached to a key, the radio coded field shape (7) and the gate (8) of entry or exit. As soon as the Semi-active tag comes within the range of the coded field, it wakes-up and starts looking for a valid data packet. When a valid data packet has been received it will carry out the preprogrammed instructions for that specific monitoring point.

An example of the Monitoring Point Unit is shown in figure 3, which consists of a microcontroller (9), a radio transmitter (10) with an ON/OFF modulation technique and a transmitting antenna (11). The radiation pattern of the transmitting antenna will define the shape of the coded field, which in part defines the tag's range of operation as shown in figure 1. The transmitting antenna produces the shape of the coded field and by selecting different antenna characteristics the shape of the coded field can be modified as shown in figure 4 for a patch antenna.

A Semi-active tag as shown in figure 5 consists of a receiving antenna (16), a radio receiver (12), a comparator and microcontroller (13), a warning device or an interfacing unit connected to the asset which renders it unusable (14), and a battery or batteries (15). The method of operation of the Semi-active tag is that it will be in sleep mode to reduce battery

power consumption and as soon it enters a coded field it will activate the microcontroller. This will result in the data processor starting to look for a valid data packet and carry out instructions or go back to sleep mode if it is a false coded field. The software used on the Semi-active tag will create the intelligence for the system.

The Semi-active tag has the ability to identify one pair or more of specific coded Monitoring Point Units and when these are identified in a certain order will trigger the alarm condition for a pre-set period of time. The tag's intelligence is that it can sense the direction it's moving in by passing through two different coded fields next to each other with different addresses, and depending on which coded field is experienced first, the tag will know in which direction it is moving.

The system's intelligence flow diagram is demonstrated in figure 6 where a Semi-active tag is attached to an asset or person (17) and there are several monitoring points (18,19, 20,21). The Semi-active tag can leave the radio fenced-area at exit points (18) and (21), for which it will create an alarm condition. However if the tag goes to the point of authorisation (20) and then goes to exit point (18) there will be no alarm condition. Monitoring points (18) and (19) will give the Semi-active tag a sense of direction by the order it receives the monitoring points. For example if it receives monitoring points code (20), (19) and then (18), it will make a decision that the tag is leaving the radio-fenced area with authorisation. Whereas if it receives monitoring points (18) and then (19), the tag will know it is entering the radio-fence area and can go to the storage area (22) by passing through monitoring point (20) without an alarm condition. Therefore the tag's intelligence is in the order which it receives the monitoring points, and the programme that defines the conditions for which the alarm is created.

Claims

CLAIMS 1. An Asset Protection System for tracking the movement of assets within a controlled area and acting upon the movement tracked, comprising: a number of Monitoring Point units comprising a location-identity transmitter each located, at a gate defining an entrance to and exit from the areas, each transmitter being able to broadcast its location into a small volume there-around; a number of identification tags provided and affixed to each asset to be tracked; each tag including sensor means able to receive and recognize the location transmissions when within a transmitter's effective volume, and also having the ability to store information pertaining to the sequence of location identity transmitters through whose gate it has passed and also includes alarm means; in which each tag is programmable with one or more permitted routes for the asset to which it is affixed, between some or all of the gate locations for the defined area, and to activate the alarm if the asset follows a path that deviates from its programmed route.
2. A system as claimed in claim 1 in which the power source in the tag is only activated when a signal is received from a Monitoring Point Unit.
3. The system of claim 2 in which the power source in the tag is activated by the receipt of predefined data from a Monitoring Point Unit.

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4. The system according to any previous claim in which data relating to the interactions between each Monitoring Point Unit and the tag is recorded on the tag.
5. The system of claim 4 in which the tag is pre-programmed to respond to data recorded on Monitoring Point Unit interactions.
6. The system of claim 5 in which the tag creates an alarm condition if signals from a defined sequence of Monitoring Point Units are received.
7. The system of claim 6 in which the tag creates an alarm condition if the tag is outside or inside a certain area for over the authorized amount of time.
8. The system according to any previous claim in which in which the Monitoring Point Units transmit at UHF or microwave frequencies.
9. The system according to any previous claim in which a patch antenna for providing a shaped field is used on one or more Monitoring Point Units.
10. A system according to any one of the previous claims, in which each Monitoring Point Unit comprises an antenna, a radio transmitter and a microcontroller.
11. A system according to any one of the previous claims, in which each tag includes an antenna, a radio receiver, a comparator, a microcontroller, an audio device and a power source

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12. An Asset Protection method for tracking the movement of assets within a controlled area and acting upon the movement tracked, comprising the steps of: positioning a number of Monitoring Point Units around the controlled area at gates defining entrances and exits from the area, each Monitoring Point Unit comprising a location-identity transmitter being able to broadcast its location into a small volume there-around, attaching a tag to the asset to be tracked, each tag including sensor means able to receive and recognize the location transmissions when within a transmitter's effective volume and also having the ability to store information pertaining to the sequence of Monitoring Point Units through whose gate it has passed and also including alarm means, transmitting data packages from each Monitoring Point Unit to a defined vicinity, pre-programming the tag to respond in a defined way to the series of signals received from Monitoring Point Units representing a route through the defined area
13. The method of claim 12 including the additional step of activating an inactive power source on the tag when a tag enters the vicinity of an Monitoring Point Unit.
14. A method according to claim 12 or claim 13 in which preprogrammed responses on the tag are audible instructions.
15. A method according to claims 12 or 13 in which the preprogrammed response is an alarm.

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16. A method according to claims 12 or 13 in which the preprogrammed response is a signal to an interfacing unit which renders the device the tag is attached to inoperable.
17. A method according to any of claims 12 to 16 including the additional step of recording on the tag data relating to interactions with each Monitoring Point Unit.
18. A method according to claim 17 in which the tag is preprogrammed to respond to the recorded data on Monitoring Point Unit interactions.
19. A method according to claim 18 in which the Monitoring Point Unit is positioned at entrances or exits of controlled areas
20. A tag for a system according to claims 1 to 11 attachable to an asset to be tracked.
21. A system substantially as herein described and referred to in Figures 1 to 6 of the attached drawings.