GB2447459A

GB2447459A - Wireless separation alarm for monitoring loss of children or property

Info

Publication number: GB2447459A
Application number: GB0704762A
Authority: GB
Inventors: Grant Edwin Phipps
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-03-13
Filing date: 2007-03-13
Publication date: 2008-09-17
Also published as: GB0704762D0

Abstract

The alarm system comprises a master unit 22, held by a guardian, with a wireless communications link to a remote unit 28, attached to property or to a child. If the units 22 and 28 are separated by a large distance or the communications signal quality deteriorates or is lost than an alarm is raised. The master unit may poll the remote unit and check for a maximum reply time or check the signal against a strength threshold. The wireless communication can be by a Bluetooth (RTM) protocol radio signals or may be a line of sight, such as via infra-red signals. The signal may be encoded, securing a unique link to the remote unit and allows monitoring of multiple remote units, eg many children. The units may be incorporated or attached to clothing or other items; figure 2 shows baseball caps worn by parent and child with electronics 24, 32 attached to antennas 26, 30 to provide a wireless link 40.

Description

Portable Alarm

FIELD OF THE INVENTION

The present invention relates to a portable alarm. It is particularly suitable for those in a position of responsibility for children, but is potentially useful in other contexts.

BACKGROUND ART

There is a light-hearted piece of advice given to those contemplating parenthood, which seeks to communicate to them the difficulties and frustrations inherent in caring for children. The advice includes several suggestions as to how a prospective parent might be able to practice in advance of the child's arrival, one of which is to visit a supermarket with a pair of untethered goats.

The prospective parent is instructed to complete their weekly shop while keeping watch on both goats.

This is obviously not a serious suggestion; most supermarkets would refuse to admit a goat for obvious reasons of hygiene. However, the point that it makes is clear; children generally find adult-oriented activities such as food shopping boring, and will try to amuse themselves by way of an alternative activity. This will often result in them wandering off without prior warning towards something more interesting, which may or may not be in the direction that the parent wishes to move. Parents therefore need to keep watch over their children at all times, and even the most devoted parents eventually find this tiresome and difficult.

For very young children, reins are available. These include a leash that is typically about a metre long, together with some form of attachment to the child. Some attach via a simple Velcro1M loop which is fastened around the child's wrist; others include a harness that is fastened around the child's chest.

These are suited to use with children that are old enough to walk but not old enough to regard the restraint as objectionable, typically around an age of about 2 years. A child much older than that would likely refuse the harness or be able to remove it.

Outside the context of childcare, there are a wide variety of situations in which it is undesirable to allow the spatial separation between two items or an item and a guardian to increase excessively.

SUMMARY OF THE INVENTION

The present invention seeks to provide a form of monitoring of younger children which provides the necessary degree of security to the parent and is compatible with the wishes of the child. It therefore provides a distance warning system comprising a master unit incorporating an alarm, a separate remote unit, and a wireless link between the two units, the master unit being arranged to monitor the wireless link to determine range information, and trigger the alarm if a specified range criterion is exceeded.

The range criterion will typically be substantially correlated with distance, although the particular properties of some wireless links may result in that correlation being less than perfect. One means of obtaining range information is for the master unit to use the wireless link to poll the remote unit and check for a maximum reply time.

The range criterion can alternatively be correlated with connection quality.

Thus, the master unit can receive a signal from the remote unit via the wireless link and check the signal against a strength threshold. As the range of the remote unit increases, the signal strength will decline and this will be detected.

The remote unit can be arranged to poll the master unit at intervals, which may be preset.

The wireless connection can be BluetoothTM, in which case the master unit can check for a valid pairing with the remote unit by way of the range criterion.

BluetoothTM connections require adequate signal strength in order to allow two devices to pair, and this therefore provides a good proxy for range.

A further possible range criterion is line of sight, for which an infra-red link is ideally suited. In this case, the remote unit can poll the master unit or it can send a continuous signal to the master unit.

The signal from the remote unit to the master unit can be encoded, for example by way of a signal that is unique to the remote unit concerned. This prevents the master unit from being confused by the presence of other remote units within range, and also enables the master unit to monitor multiple remote units and warn if any one of the remote units exceeds the range criterion.

The remote unit is preferably attachable to a child, such as by way of a suitable hook and loop fastening, or by being associated with an item of clothing, for example. The latter can be achieved by containing the remote unit within the item of clothing; suitable items of clothing include hats and coats.

The invention could be applied to other situations in which excessive spatial separation is undesirable, such as a lap-top computer or holiday luggage.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the present invention wilJ now be described by way of example, with reference to the accompanying figures in which; Figure 1 illustrates the principal of a range criteria-based distance alarm according to the present invention; Figure 2 illustrates an embodiment of the invention; and Figure 3 illustrates the operation of a line-of-sight device.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Losing a child is probably the greatest fear of any caring parent. Many parents fear that their children could be abducted, although the actual likelihood of this is very low indeed. There is however, a very strong likelihood that a child will meander off toward something that interests them, without realising that they have lost sight of their parent. If the parent is distracted, such as during a shopping trip, there is every possibility that neither the parent nor the child will realise that contact has been lost until the child is (potentially) some distance from the parent. At this point, it can be most distressing both for the parent and for the child as they seek to re-establish contact with the other.

Figure 1 demonstrates schematically a system for alerting either party to the fact that a specific range criterion has been exceeded. A central master unit includes a radio-transceiver 12 having an aerial or the like 14. A plurality of remote units 16a, 16b and 16c each include transceiver units 18a, 18b and 18c.

Each of these is, in turn, associated with an aerial or the like 20a, 20b and 20c.

At a preset interval of (say) one second, the master unit 10 prompts its radio transmitter 12 to poll each of the remote units 16a, 16b and 16c. Each signal comprises a broadcast request for a response by a specific unit, and the remote units 16a are programmed to receive these via the aerial 20 and transmitter until 18, check whether the signal is intended for them and, if so, reply immediately via a suitably encoded response signal.

The master unit 10 must interpret the result of this. If no response signal is received from a specific remote unit 20 then clearly that remote unit is out of range. This should trigger an alarm state for the master unit 10. A round trip response delay of more than (say) lOOms (plus processing time) would indicate a distance of approximately 15 metres (via electromagnetic transmission) and would be about right for parents of small children. A higher time limit might be applicable for parents of older children; accordingly the master unit should be programmable with a sensitivity level.

The base unit can send an alert signal addressed to the particular remote unit 16 confirming that they are beyond range; if this is received by the remote unit, or if they have not received a polling signal within a specified time such as three or four times the polling interval of the base unit 10, then the remote unit can enter an alarm state.

When either unit enters an alarm state, this can be communicated to a user by way of visible, audible or other alarms, or some combination of both. A flashing light is a visible example of warning state, and this may be combined with warning beeps, warning tones, vibrations of the unit and the like. In the case of the remote unit, a bright upwardly directed light will help locate the child if indoors.

Figure 2 illustrates the association of the device together with an item of clothing, in this case a baseball cap. A parent's baseball cap 22 includes the necessary electronics 24 strapped to the side band of the hat together with a transmitting antenna 26 on top of the hat. Likewise, the child's hat 28 includes an antenna 30 on the top which is connected to the necessary electronics 32 on the hat band. In this way, if the child exceeds a maximum range 34 from the master unit 10, a warning state is initiated in both units. Integration of the device into headwear can be particularly advantageous in that ear pieces 36, 38 can be provided, to be worn together with the hat to render any warning tones somewhat more discreet.

The above-describe embodiment employs a radio frequency transmission, which, in this case, is bespoke to the particular embodiment. However, an off the shelf radio communication system is available in a form of the BluetoothTM communications protocol, which is typically used for allowing intercommunication between electronic devices via temporary radio links.

BluetoothTM devices need to be "paired" on first use, via process of synchronisation between the two units, which allows the units to learn an association with each other.

If the connection is broken through inadequate signal quality, then this is reported back to the controlling device. The loss of a BluetoothTM pairing typically occurs at a range of about 20 metres, which be adequate warning that the range criterion had been exceeded. Alternatively, the units could exchange information via the BluetoothTM link, and if information is not forthcoming then they can deduce that the BluetoothTM connection has been lost. That information could also put to use; it could include information such as timing data, which would reveal the time of flight of the messages. Alternatively, or in addition, the devices could each be integrated with GPS transceivers and thus exchange location information, which would enable an immediate and accurate determination of the distance between them. This would also allow the parent to be guided towards the child's last known position if contact was lost.

An alternative and potentially simpler arrangement is for a line of sight communication means. This is shown integrated into figure 2, if the aerials 26, are interpreted as infrared transceivers. If a line of sight communication such as that illustrated at 40 can be maintained between the two transceivers, then the range of criterion can be considered met. As shown in figure 3, if the parent 42 is within a direct line of sight of the child 44 then generally they can locate the child simply by looking around. They wish to be warned as soon as the child leaves that line of sight by moving position such as that shown at location 44 where the child is obscured by an item such as a supermarket shelf 46.

Given that children are generally less tall than parents, it would be advisable to provide repeated transceivers around at least the parent's hat, shown as 48 in figure 2. These may also be provided on the child's hat.

To provide protection in other contexts, such as preventing theft of an item, the remote unit can be attached to the item via a keyring, lanyard, cable tie or (in the case of a (laptop) a "Kensington" lock, or the like. The base unit can be integrated into an item of clothing, or can be carried about the person, as described above.

It will of course be understood that many variations may be made to the above-described embodiment without departing from the scope of the present invention.

Claims

1. A distance warning system comprising a master unit incorporating an alarm, a separate remote unit, and a wireless link between the two units, the master unit being arranged to monitor the wireless link to determine range information, and trigger the alarm if a specified range criterion is exceeded.

2. A distance warning system according to claim 1 in which the range criterion is substantially correlated with distance.

3. A distance warning system according to claim 2 in which the master unit uses the wireless link to poll the remote unit and check for a maximum reply time.

4. A distance warning system according to claim 1 in which the range criterion is correlated with connection quality.

5. A distance warning system according to claim 4 in which the master unit receives a signal from the remote unit via the wireless link and checks the signal against a strength threshold.

6. A distance warning system according to claim 4 or claim 5 in which the remote unit polls the master unit at intervals.

7. A distance warning system according to claim 6 in which the intervals are preset.

8. A distance warning system according to any one of the preceding claims in which the wireless connection is BluetoothTM.

9. A distance warning system according to claim 8 in which the master unit checks for a valid pairing with the remote unit.

10. A distance warning system according to claim 1 in which the range criterion is line of sight.

11. A distance warning system according to claim 10 in which the wireless connection is an infra-red link.

12. A distance warning system according to claim 11 in which the remote unit sends a continuous signal to the master unit.

13. A distance warning system according to claim 11 in which the remote unit polls the master unit at intervals.

14. A distance warning system according to claim 13 in which the intervals are preset.

15. A distance warning system according to claim 13 or claim 14 in which the signal from the remote unit to the master unit is encoded.

16. A distance warning system according to claim 15 in which the encoded signal is unique to the remote unit concerned.

17. A distance warning system according to any one of the preceding claims in which the remote unit is attachable to a child.

18. A distance warning system according to claim 17 in which the remote unit includes a hook and loop fastening.

19. A distance warning system according to claim 17 in which the remote unit is associated with an item of clothing.

20. A distance warning system according to claiml9 in which the remote unit is contained within the item of clothing.

21. A distance warning system according to claim 19 in which the item of clothing is one of a hat and a coat.

22. A distance warning system substantially as herein described with reference to and/or as illustrated in the accompanying figures.