WO2008012377A1

WO2008012377A1 - Locating system that uses personal radiobeacons

Info

Publication number: WO2008012377A1
Application number: PCT/ES2006/070119
Authority: WO
Inventors: Juan José DÍAZ MENÉNDEZ; Sebastián RODRÍGUEZ NÚÑEZ; Lucio HERNÁNDEZ GARCÍA
Original assignee: Indra Sistemas, S.A
Priority date: 2006-07-28
Filing date: 2006-07-28
Publication date: 2008-01-31

Abstract

Locating system that uses personal radiobeacons. The system also comprises at least one controller/receiver device with an antenna and a GPS antenna receiver, associated with a display means. Each personal radiobeacon comprises an antenna and a GPS antenna receiver and upon activation emits an analogue help signal, whose modulating wave consists of sweeps of descending audio frequency separated by intervals of silence, which may be received and demodulated by the controller/receiver device. Respective binary modulating signals from the respective radiobeacons are inserted in the intervals of silence of the analogue help signal, which carry data with additional information obtained by means of the GPS antenna receiver of the radiobeacon, whose instant of transmission for each radiobeacon is governed by the time information of the GPS system, and which can also be received and demodulated by the controller/receiver device.

Description

SYSTEM. LOCATOR THAT USES PERSONAL RADIOBALIZES

FIELD OF THE INVENTION

The present invention relates to a location system that uses personal radio beacons, and that has a special application in the tasks of search and rescue of people and objects.

STATE OF THE PREVIOUS TECHNIQUE There are systems used in the tasks of search and rescue of people based on the use of beacons carried by the people to whom you want to locate. These systems can have multiple applications in tasks of control and monitoring of people for their safety and their possible rescue in emergency situations. For example, they may have a special application in the search and rescue tasks of people who accidentally fall into the sea from a boat, or in the control of forest patrol members on firefighting mission. These systems are also applicable to the search and rescue of objects.

In the specific case of shipwreck search and rescue systems ("man-to-water" incidents), personal beacon is usually carried on the life jacket and emits an analog distress signal at 121.5 MHz or 243 MHz. receive on the ship's bridge of government.

The waveform of the distress signal at 121.5 MHz or 243 MHz is defined by the recommendation of the International Telecommunication Union ITU-R M.690-1 ("Technical characteristics αe the αaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa) carrier frequencies of 121.5 MHz and 243 MHz "). Although this recommendation was envisaged for claims radio beacons (such as shipwrecks) it has also been adopted as the signal analog distress beacons that emit them in person ^¬ incidents of type ^"" man overboard "that are typically resolved from the ship itself (ie," in proximity . ") The European standard ETSI EN 300 152-1 ( "Electromagnetic compatibility and Radio spectrum Matters (ERM); Maritime Emergency Position Indicating Radio Beacons (EPIRBs) intended for use on the frequency 121.5 MHz or the frequencies 121.5 MHz and 243 MHz for homing purposes only; Part 1: Technical characteristics and methods of measurement ") is an example of how the international community is adopting the waveform defined by ITU-R recommendation M.690-1 for" man-in-the-water "incidents.

There are other types of radio-beacon locator systems that use digital signals and have substantial differences with respect to the systems described above for incidents of the ^ΛΛ man-to-water ”type (also called“ proximity ”locator systems.) For example, claims beacons. (such as shipwrecks) are also used in the maritime field and are designed to be released by themselves in case of sinking of the ship.The distress signal is transmitted with the power necessary to reach the CORPAS-SARSAT satellite system, which it picks up the distress signal and relays it later when it passes over certain stations on the ground. The distress signal is emitted at 406 MHz {there are also satellites operating at 121.5 MHz that are expected to cease their service at this frequency). Relief of this type αe sinister differ from the actions in ios man-to-water incidents, since In these, the incident must be resolved by the ship itself without warning the CORPAS-SARSAT satellite system (reserved for the resolution of claims), whose speed of response is substantially less than that of the ship itself.

One type of accident beacons are EPIRB beacons (emergency position indicating beacon: "Emergency Position Information Radio Beacon"). Usually, EPIRB radio beacons transmit data information in 406 MHz to CORPAS-SARSAT satellites using a digital signal other than the analog distress signal of personal radio beacons. This signal from EPIRB radio beacons is defined by the recommendation of the International Telecommunication Union ITU-R M.633-2 ("Transmission characteristics of a satellite emergency position-indicating radio beacon {satellite EPIRB) system operating through a satellite system in the 406 MHz band ").

U.S. Pat. US 6388617 provides an EPIRB type beacon, of those used to send an emergency signal from a ship to the satellite system when it is in trouble and requires help. Said patent, which, as indicated, is oriented towards EPIRB type beacons, instead of personal beacons (also known by its acronym in English as PLB: "Personal Locator Beacon"), makes use of the GPS navigation system (" Global positioning system ", or global positioning system) to obtain information geographical posi ^¬ tion. This patent proposes a system that reduces the consumption of the beacon battery while retaining recent data from the information obtained by GPS in the beacon's memory, which allows the battery life to be extended.

There are also personal radio beacons in 4ub ivihiz / 121.5 MHz, which are preferably used in terrestrial applications for assistance in mountain climbing or hiking incidents. These are radio beacons that are manually activated by the user, and that transmit the signal from 406 MHz relief to be captured by the CORPAS-SARSAT satellite system. This type of radio beacon also emits, with less power, a 121.5 MHz signal that is used for the final location in proximity. To make use of this service it is necessary to register the bearer of the radio beacon with the NESDIS (National Environmental Satellite, Data and Information Device). It is a service of the US government. through NOAA (National Oceanic & Atmospheric Administration). These radio beacons, in general, are not suitable for "man-to-water" applications, since their signal is not received on the ship's bridge and they are not usually equipped with an automatic activation mechanism in case of immersion . In general, radio beacons (personal or EPIRB) that use the CORPAS-SARSAT satellite system cannot offer immediate help, since the minimum response time of this system can be estimated at around 90 minutes. Returning to the "man-to-water" incident locator systems (also called proximity ^λλ locator systems) in the aforementioned ITU-R recommendation M.690-1 it is described that the analog distress signal does not carry more information than a characteristic audio signal, allowing receivers in 121.5 MHz or 243 MHz to demodulate an alarm signal at the time of the "man in the water" incident. Therefore, the use of this type of auditory signal only allows the alert without facilitate search and location tasks Some receivers, using radio ^¬ niometry techniques, can also indicate the direction αe arrival of the distress signal, without being able to provide more information given the intrinsic limitations of the distress signal defined by the ITU recommendation -R M.690-1 Due to their characteristics, these receivers do not manage so adequate situations in which there is more than one active beacon, unable to indicate the correct direction of two or more active beacons at the same time.

There are also personal radio beacons that transmit the distress signal at 121.5 MHz along with a digital selective call (in English, Digital Selective Calling) on another VHF frequency.

The Spanish patent ES 2014359 ("Alarm system and location by radio signals") is an example of a transmitter-receiver system with acoustic and / or optical alarm signal and which allows to know in which direction the castaway is.

Although there are multiple location systems that employ personal radio beacons that emit analog distress signals, these systems have the disadvantage that, in those cases where more than one radio beacon is activated, the management of the system can be problematic.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a localization system in proximity by means of personal beacons that allows to identify and position separately, and without interference, the emissions of several simultaneously active beacons, all immediately.

The invention relates to a locator system that uses personal radio beacons, which also comprises at least one controller-receiver device comprising an antenna and a GPS antenna-receiver and is associated with a visualization means, in which each of said Personal radio beacons comprise an antenna and a GPS antenna-receiver, so that the personal radio beacons, when activated, can emit an analog distress signal whose modulating wave consists of audio sweeps. descending frequency separated by zones of silence that can be received and demodulated by the at least one controller-receiver device, in which various additional information can be obtained through the GPS-antenna of the radio beacon, so that in the zones of silence of the distress signal is inserted respective binary modulating signals, coming from the respective radio beacons, that carry data with the various additional information obtained by the radio-beacon GPS receiver, whose transmission moment for each beacon is governed by the time information supplied by the GPS system, and which can also be received and demodulated by the at least one controller-receiver device. By inserting binary modulating signals into the silence zones of the analog distress signal and the fact that the moment of transmission of said signals for each radio beacon is governed by the GPS system, it is achieved that each beacon transmits the corresponding additional signal at a designated instant, thereby avoiding interference between the emissions of several simultaneously active radio beacons.

According to further embodiments of the invention, the analog distress signal may be 121.5 MHz or 243 MHz.

Therefore, an additional advantage of the system is that it can be used with the receivers currently in service at the frequencies of 121.5 MHz or 243 MHz.

According to another embodiment of the invention, the binary modulating signals comprise geogratic position coordinate data and the instant of the radio beacon activation.

According to another embodiment of the invention, the binary modulating signals are FSK ("Frequency Shift Keying") signals. „Η __

According to another embodiment of the invention, the binary modulating signals are PSK ("Phase Shift Keying") signals.

Preferably the shape of the modulating wave of the analog distress signal consists of a descending audio frequency sweep in a range not less than 700 Hz, between 1600 Hz and 300 Hz, and with a sweep repetition frequency of 2 to 4 times per second.

More preferably, the descending audio frequency scan is performed between 1200 Hz and 400 Hz.

Therefore, another additional advantage would be the rapidity of the sweep repetition, which would allow to obtain data from several radio beacons in a relatively short time. According to another embodiment of the invention the display means is a radar screen.

According to another embodiment of the invention, the display means is a screen with user interface.

According to another embodiment of the Invention, the radio beacons are integrated into a garment of a vest or similar type.

According to another embodiment of the invention, the radio beacons are activated by an automatic water immersion activation mechanism.

BRIEF DESCRIPTION OF THE DRAWINGS

An illustrative, and in no way limiting, embodiment of the object of the present invention will be described below, with reference to the accompanying drawings, in which:

Figure 1 shows a basic scheme of the locator system of the invention, with a personal beacon.

Figure 2 shows a graph of the frequency as a function of time, corresponding to the analog distress signal and the inserts of the data signals in the silence zones of the analog distress signal.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 illustrates in a very schematic way the locator system of the invention, in which a personal radio beacon and a receiver have been represented. ^¬ not prejudge you, in most cases localized tion systems consist of several personal radio beacon devices and one or more receivers or transceivers controllers. The controller-receiver device may consist of a panel computer that integrates the receiver capable of receiving the analog signal from the radio beacons. Said device may further comprise an antenna, a GPS antenna-receiver (which, in marine salvage applications, allows to know the position of the vessel) and be associated with a display means (which can be, for example, a screen with user interface) . In this screen you can locate, for example, the geographical position information transmitted by the radio beacons. The controller-receiving device can also, for ahem ^¬ ple, provide the information received by the personal radar screen beacon boat, allowing to concentrate all the graphic representation on a ma ^¬ sists. On the other hand, each of the personal radio beacons comprises an antenna and a GPS antenna-receiver. When personal radio beacons are activated, they emit an analog distress signal whose modulating wave consists of descending audio frequency sweeps (they are represented graphically in Figure 2 with the indication "Audio") separated by zones of silence. That analog signal is received and demodulated by the controller-receiver device. In addition, the radio beacon's GPS antenna receiver allows obtaining various additional information, such as the precise Instances of occurrence (or "tics") of the seconds (that is, the PPS signal, in English "Pulse Per Second", of the GPS system).

As can be seen in figure 2, in the silence zones of the analog distress signal, binary modulating signals (represented as DATA 1, DATA 2, etc.) are inserted, respectively, from radio beacons 1, 2 , etc. These signals carry data with the various additional information obtained through the GPS antenna-receiver of the corresponding radio beacon. In addition, the transmission time for each radio beacon is governed by the time information provided by the GPS system. Said binary modulator signals are also transmitted to the controller-receiver device, which can also receive and demodulate them.

Preferably, in marine rescue applications for "man-in-the-water" incidents, the analog distress signal is transmitted in 121.5 MHz or 243 MHz, as established by ITÜ-R M.690-1. The data comprising the binary modulating signals can be the coordinates of geographical position (longitude and latitude) and the instant of activation of the beacon. In the case of marine rescue applications, this instant of activation of the beacon must coincide with the moment of immersion of the beacon in the water.

The binary modulating signals (or data signals) indicated above may be, for example FSK ("Frequency Shift Keying") signals, PSK ("Phase Shift Keying") signals, etc.

As described in the ITU-R recommendation M.690-1, the modulating waveform signal in consis relief ^¬ will sweep downward audio not less than 700 Hz range between 1600 and 300 Hz, and a repeat sweep frequency of 2 to 4 times according to do. A typical multiplexing of this modulating waveform is said sweeps separated by zones of silence, as can be seen in Figure 2. In a preferred embodiment of the invention, said descending audio-frequency scan is performed between 1200 Hz and 400 Hz

It is noteworthy that the locator system of the invention has multiple applications, such as the search and rescue of people who accidentally fall into the sea from a vessel (maritime rescue), the search and retrieval of objects (in military applications, for example, training torpedoes), the control of the members of forest patrols in firefighting mission and, in general, the simultaneous control of the position of the components of any group of mobile elements.

As we have indicated, one of its main applications is in the tasks of maritime rescue ("man in the water" incidents). In this case, the personal radio beacon would be integrated into a garment of the castaway, usually the life jacket. The controller-receiver device would be located on the ship's bridge, which could receive both the 121.5 MHz or 243 MHz analog distress signal and personal radio beacon data signals, such as its geographical position or the instant of falling into the water. In this specific application, personal radio beacons would be activated by means of an automatic water immersion activation mechanism of those commonly used.

According to Figure 2, when a person falls into the water, his radio beacon sends the analog distress signal ("Audio") and the corresponding data signal (DATA i). The moment in which said DATA 1 signal is transmitted is governed by the time information provided by the GPS system. Thus, when a second person falls into the water, his radio beacon will also emit his corresponding data signal (DATA 2} at a different time than the transmission of the DATA 1 signal and also governed by the time information provided by the GPS system. In the same way it would happen with successive radio beacons. several radio ^¬ beacons simultaneously activated, each of them transmitting it at a designated instant, thereby avoiding interference between the emissions of said beacons and allowing easy identification and detection of position separately.

Although an embodiment of the invention has been described and represented, it is evident that modifications within the scope of the invention can be introduced therein, which should not be considered limited to said embodiment, but only to the content of the following claims:

Claims

1.-Locator system that uses personal radio beacons, which also comprises at least one controller-receiver device comprising an antenna and a GPS antenna-receiver and is associated with a visualization means, in which each of said radio beacons personal includes an antenna and a GPS antenna-receiver, so that the personal radio beacons, when activated, can emit an analog distress signal whose modulating wave consists of descending audio frequency sweeps separated by zones of silence that can be received and demodulated by the less a controller-receiver device, in which various additional information can be obtained by means of the GPS-antenna of the radio beacon, characterized in that in the silence zones of the analog distress signal respective binary modulating signals are inserted, from the respective radio beacons , which carry data with the various additional information obtained given by the radio beacon GPS receiver, whose transmission instant for each beacon is governed by the time information supplied by the GPS system, and which can also be received and demodulated by the at least one controller-receiver device.

2. A locator system using personal radio beacons, according to claim 1, characterized in that the analog distress signal is 121.5 MHz.

J.- Locator system using personal radio beacons, according to claim 1, characterized in that the analog distress signal is 243 MHz. "1 ^* 3

- _L or -

4.-Locator system that uses personal radio beacons, according to any of the preceding claims, characterized in that the binary modulating signals comprise data of the geographical position coordinates and the instant of activation of the beacon.

5.-Locator system that uses personal radio beacons, according to any of the preceding claims, characterized in that the binary modulating signals are FSK ("Frequency Shift Keying") signals.

6.-Locator system using personal radio beacons, according to claims 1 to 4, characterized in that the binary modulating signals are PSK ("Phase Shift Keying" signals).

7.-Locator system using personal radio beacons, according to any of the preceding claims, characterized in that the shape of the modulating wave of the analog distress signal consists of a descending audio frequency sweep in a range not less than 700 Hz, between 1600 Hz and 300 Hz, and with a repeat sweep frequency of 2 to 4 times per second.

8.-Locator system using personal radio beacons, according to claim 7, wherein the descending audio frequency scan is performed between 1200 Hz and 400 Hz.

9.-Locator system that uses personal radio beacons, according to any of the preceding claims, characterized in that the display means is a radar screen.

10.-Locator system using personal radio beacons, according to any of claims 1 to 8, characterized in that the display means is a screen with user interface.

11.-Locator system that uses personal beacons, according to any of the preceding claims, characterized in that the beacons are integrated into a vest-type garment or similar.

12. - Locator system using personal radio beacons, according to claim 11, characterized in that the beacons are activated by an automatic activation mechanism by water immersion.