GB2368489A

GB2368489A - Using power saving methods and coded transmission in a device for locating missing people/objects, e.g. person buried in avalanche

Info

Publication number: GB2368489A
Application number: GB0015172A
Authority: GB
Inventors: Jeremy Dunkin; Michael Dunkin
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-06-22
Filing date: 2000-06-22
Publication date: 2002-05-01
Also published as: GB0015172D0

Abstract

The invention relates to a radio frequency system for remote location of one or more movable entities such as skiers buried in avalanches, lost hikers or climbers or any other object that needs to be located e.g. animals, vehicles. More particularly, a transmitter/receiver 10 located with the entity uses intermittent reception and triggered transmission to extend battery lifetime and enable the use of smaller batteries 18. The system comprises a portable unit 10 and a search unit (20, fig.2), each having a transmitter portion 16 and a receiver portion 14. The portable unit 10 is adapted to be carried by the entity and the receiver portion 14 of the portable unit normally operates intermittently, e.g. 10 milliseconds per second. The search unit (20) is able to transmit a coded signal and if the portable unit 10, during operation, receives a coded signal that it recognises, i.e. its own code, it is triggered to respond by actuating its transmitter 16 to transmit a unique coded signal for a predetermined period of time. The search unit (20) is able to receive this signal. In another aspect, each of a dispersed group of movable entities carries a portable unit 10 and the search unit (20) is capable of selectively transmitting any one of a series of differently coded signals, each recognisable by only one of the portable units 10. The portable unit 10 may switch from intermittent operation to a continuous mode long enough to check the incoming code against that in its memory 17. The search unit (20) may be portable and able to be connected to a central processing unit or PC for information exchange, e.g. to download from the internet the names and codes of the portable units' owners.

Description

REMOTE LOCATION SYSTEM This invention concerns a system for remote location of a movable entity. More particularly, it is concerned with pinpointing the position of hikers, ramblers, skiers, climbers and others when they are lost or in difficulties in the countryside, for example in cases of avalanche, accident or poor weather conditions.

However, the invention may have application in many other fields where it is desirable to determine quickly and accurately the position of people, animals, vehicles or other objects. Whenever skiers, climbers or hikers are reported missing, or an avalanche has occurred which has buried people, sometimes buildings, speed is of the essence. The despatch of a rescue team may take some time, but this is time which the casualties/victims may not have. Particularly in the case of avalanches, the chances of survival rapidly diminish over a period of a few hours. After two hours burial, the chances are already as low as 25%.

During the winter ski season of 1999 large numbers of people were buried by avalanches that swept across the Galtour area. Many were killed simply because their location could not be pinpointed quickly enough. An object of the invention is to speed up location of a buried person, thus increasing their chances of survival. A further object is to make the search operation safer for rescue personnel, by only allocating them to areas of need. More generally, the present invention addresses the problem of locating people lost in the countryside, often in rough terrain and poor weather conditions and seeks to provide a costeffective, yet reliable system which does not rely on any action on the part of the lost individual. Use of radio frequency transmitter/receiver units by groups of off-piste skiers and other groups of hikers or people taking part in outdoor activities is, of course, known. But in those cases, the units concerned were much larger and more expensive than envisaged in accordance with the present invention, and signal transmission was continuous, resulting in the need to recharge batteries after only a few days. Moreover, the arrangement was such that each person within the group had to be trained how to use his/her unit in a specific search pattern to search for any other member who became lost or engulfed in an avalanche.

Smaller, less expensive, so-called"passive"locator units have also been used by skiers and other outdoor enthusiasts. These have comprised discs of ceramic material each with an encased electronic component, designed to reflect back a signal transmitted from a central search transmitter. They have not proved to be effective, particularly for long range searches, owing to the weakness of any reflected signal, and the fact that whether or not the signal is reflected at all may depend on the orientation of the disc on the body of the lost individual.

The present invention proposes a system for remote location of a movable entity comprising a portable unit adapted to be carried by the entity and a search unit, the portable unit and the search unit each having a transmitter portion and a receiver portion which are capable, respectively, of transmitting and receiving radio frequency radiation, the system being such that the receiver portion of the portable unit normally operates intermittently and if, during operation, it receives a coded signal it recognises the associated transmitter portion is actuated to transmit a unique coded signal for a predetermined period of time, the search unit being operable, respectively, to transmit and receive the aforesaid coded signals.

The reference herein to a movable entity should be understood to mean a person, animal, vehicle or other object which is capable of moving, within an outdoor terrain or an environment of any kind. Thus, although the invention has particular application to searching for lost individuals in the countryside, it is potentially applicable to many other situations. In practical situations, the system will usually be set up to locate any of a number of individuals who are active within the relevant area of countryside. Thus, within the same concept the invention also proposes a system for remote location of a selected movable entity from a dispersed group of movable entities comprising a plurality of portable units, each of which is carried by a respective one of the group of entities, and a search unit, each portable unit and the search unit having respective transmitter and receiver portions capable, respectively, of transmitting and receiving radio frequency radiation, the system being such that the search unit is capable, selectively, of transmitting any one of a series of differently coded signals, each recognisable by the receiver portion of only one of the portable units, that each portable unit normally operates intermittently and if, during operation, it receives a coded signal it recognises, the associated transmitter portion is actuated to transmit a unique coded signal for a predetermined period of time, which coded signal can be received by the search unit. The invention will now be described further by way of example, by reference to the accompanying drawings in which: Figure 1 is a block diagram of a personal portable unit of a system in accordance with the invention; and

Figure 2 is a block diagram of a search transceiver unit of the transceiv same system. The exemplary system will be described with reference to its use for location of a person lost in the countryside. The exemplary system consists of two parts, namely a personal portable unit (10) (fig. 1) and a search transceiver unit (20) (fig. 2) which is equipped to locate the personal, portable unit. The portable unit (10) is located on the person either by the individual him or herself or during the manufacture of a product or piece of clothing either purchased by or allocated to that individual and worn or carried by them. The person in possession of the portable unit (10) does not need any knowledge of its operation or the system in general in order for it to function as designed.

The portable unit (10) is a radio frequency transceiver but it only functions as a transmitter when triggered to do so by the request of the search transceiver unit (20) which may, for example, be held by a rescue team.

More specifically, the portable unit (10) illustrated in Fig. 1 comprises surface mount electronic components namely a microchip processor (12) connected respectively to a receiver part (14), a transmitter part (16). The processor (12) is also connected to a power source in the form of a lithium battery cell (18) which is available in thin form to provide a much smaller size product than anything currently available. An aerial system (15) is arranged to serve both the receiver and transmitter parts (14), (16). A memory cell (17), which is capable of storing a unique coded sequence, is also connected to the microchip processor (12). This coded sequence can be input at the time of manufacture or supply or changed via input/output port (19). It can be accessed and transmitted when the microchip (12) receives the necessary trigger from the receiver part (14) of the unit. To get a reasonable search range the personal portable transceiver unit (10) will need to be switched to"active"mode on the person to be located. To get a reasonable life from the battery (18) the receiver part (14) of the unit (10) will be on a short-ON long-OFF cycle, e. g. 10 milliseconds in 1 second i. e.

1%, and the transmitter part (16) will be switched off. Usually the system will include a plurality of portable units (10) for each search unit (20). Each portable unit (10) will have its own unique code, which may be in the form of a number, stored in the memory cell (17), as mentioned above, and this will correspond to a unique transmission code which can be transmitted by the search unit (20) and transmitted back by the transmitter part (16) when the person is being searched for. A register of the names of owners of personal units (10) and their coded numbers will be kept. This register could be available on the Internet on a secure link for downloading and loading into the search transceiver unit (20) when required. Location of a person in possession of one of the portable unit transreceivers (10) would be the function of the search transceiver unit (20) which would locate and instruct the portable unit transreceiver to transmit it's exact location. Upon receipt of the correct code in-band radio signal from the search transceiver (20) the portable unit receiver part (14) will go from its short-ON long-OFF cycle to continuous mode for a long enough period to check the incoming code against that in the memory (17). Then, under control of the microchip (12), the same coded signal will be transmitted by the transmitter part (16) for a predetermined period.

The search transceiver unit (20) illustrated in Figure 2 comprises a microprocessor (22) connected to a receiver part (24) and a transmitter part (26), respectively, in a similar manner to the portable unit (10). The microprocessor (22) is also connected to an aerial system (25), a power source, which may be both a battery (28) or main power (21), a display screen (23), a keyboard (27) and an input/output port (29). The search unit (20) may itself be portable and will then be disconnected from the main power supply (21) and rely on the battery (28) for The aerial system (25) of the search transceiver unit (20) will have a variable angle, and may or may not incorporate phased array technology, so as to be capable of sweeping a wide range of terrain. The display screen (23) on the unit (20) will indicate receipt of a valid signal and its direction. The power for the entire system is primarily provided in the search transceiver unit, as it is this which is operated to transmit (from part (26) ) the relevant coded signal of the portable unit (10) which is being sought possibly for a prolonged period, and simultaneously has its receiver part (24) operating to try and locate any reciprocated signal from the relevant portable unit (10).

Data may be up and downloadable from the search transceiver unit (20), via its port (29), to a PC or on site laptop for deployment or analysis and data may also be input via the keyboard (27). If the system were to be adopted by skiers, every fleece, every ski coat and every pair of'salopettes provided with the portable transceiver unit (10) would enable any rescue team, ambulance crew or expedition leader suitably equipped with a search transceiver (20) to locate a casualty faster than hitherto, giving the skier the additional vital minutes needed for survival.

In the event of avalanche, the normal time consuming and labour intensive process of probing the suspected burial area with long poles, as a line search, would become obsolete.

In addition to its application by skiers or in ski resorts, the system of the invention may have applications, for example, in high earthquake risk zones, for the safe location and retrieval of missing or injured person by mountain rescue teams, and for the safe despatch and location of MR personnel themselves, by fire services, to safely and successfully monitor the position of personnel at the front end of operations, by health services for patient and safety orientated staff tracking, and also in military training and deployment.

Claims

CLAIMS 1. A system for remote location of a movable entity comprising a portable unit adapted to be carried by the entity and a search unit, the portable unit and the search unit each having a transmitter portion and a receiver portion which are capable, respectively, of transmitting and receiving radio frequency radiation, the system being such that the receiver portion of the portable unit normally operates intermittently and if, during operation, it receives a coded signal it recognises the associated transmitter portion is actuated to transmit a unique coded signal for a predetermined period of time, the search unit being operable, respectively, to transmit and receive the aforesaid coded signals.
2. A system for remote location of a selected movable entity from a dispersed group of movable entities comprising a plurality of portable units, each of which is carried by a respective one of the group of entities, and a search unit, each portable unit and the search unit having respective transmitter and receiver portions capable, respectively, of transmitting and receiving radio frequency radiation, the system being such that the search unit is capable, selectively, of transmitting any one of a series of differently coded signals, each recognisable by the receiver portion of only one of the portable units, that each portable unit normally operates intermittently and if, during operation, it receives a coded signal it recognises, the associated transmitter portion is actuated to transmit a unique coded signal for a predetermined period of time, which coded signal can be received by the search unit.
3. A system as claimed in claim 1 or 2 wherein the search unit includes a visual display.
4. A system as claimed in claim 1, 2 or 3 wherein the search unit includes a wide angled aerial system.
5. A system as claimed in any preceding claim wherein the search unit is connectable to a central processing unit or a personal computer terminal, for exchange of information therewith.
6. A system as claimed in any preceding claim wherein the search unit is itself portable.
7. A system as claimed in any preceding claim wherein the or each portable unit is battery powered.
8. A system as claimed in any preceding claim wherein the receiver part of each portable unit as carried by a

respective entity is normally operational for between 10' and 10-. 5 of any given time period.
9. A system as claimed in any of claims 1 to 5, or 7 to 9 wherein the portable unit is accommodated within a pocket of a garment.
10. A system for remote location of a movable entity substantially as hereinbefore described with reference to and as illustrated by the accompanying drawings.