FR2883093A1 - User e.g. skier, locating and alerting method for rescue party, involves making device to detect emergency situation, transmitting emergency signal to monitor and searching user by GPS module with same characteristics as that of user module - Google Patents

Abstract

The method involves providing a locating and alerting device (15) carried by a user e.g. skier, and having a global positioning system locating module that provides the position of a user. The device is constructed to detect an emergency situation of the user and to remotely transmit an emergency signal containing the position of the user, to a monitor (12). The user is searched for by another module having the same characteristics as that of the former module. An independent claim is also included for a locating and alerting system for implementing a method to locate and alert a user.

Description

METHOD AND SYSTEM FOR ALERTING AND LOCATING A PERSON IN

DISTRESS

  FIELD OF THE INVENTION The present invention relates to a method and system for alerting and locating a person in distress, for example a skier buried under an avalanche or a sailor lost at sea.

  DISCUSSION OF PRIOR ART An off-piste skier can today equip himself with a radio transmitter. In the event of an avalanche burst, rescuers may attempt to locate the buried skier at the avalanche site using radio receivers that can pick up radio signals from the skier's transmitter. However, such a system requires that rescuers first know the position of the avalanche so as to get close to the buried skier to capture the radio signals it emits.

  The publication FR 2 783 607 describes a method and an infrastructure for locating a person buried under an avalanche. The infrastructure consists of several stations each monitoring a portion of a geographic area. The buried person carries a transmitter that provides a radio signal received by one of the monitoring stations which then sends an alert signal to a rescue center. The approximate position of the avalanche is determined from the identification of the monitoring station at the origin of the alert. Relief is then sent to the spot and have means to more accurately determine the position of the buried person.

  Such a location method requires the establishment of a relatively large number of monitoring stations to allow a sufficiently accurate location of the avalanche otherwise the rescue may lose considerable time to accurately determine the position of the buried person . This therefore entails very high installation costs.

  The GPS system (Global Positioning System) allows a user to know his position from signals transmitted by a satellite network. However, currently commercially available GPS systems are designed to provide a position with an accuracy of the order of one hundred meters. As a result, even if a user in a distress situation were able to communicate the position provided by the GPS system to rescue services, the rescuers could find it difficult to reach the user in distress because of the inaccuracy of the system. the position provided by the GPS system.

  SUMMARY OF THE INVENTION The present invention relates to a method and system for alerting and locating a person in distress, the implementation of which can be carried out at low cost and making it possible to obtain the position of the person in danger. distress with sufficient accuracy for rapid intervention of the relief.

  According to another object of the present invention, the transmission of the alert can be carried out automatically.

  According to another object of the present invention, the transmission of the alert can use existing communication networks.

  To achieve these objects, the present invention provides a method of alerting and locating a user in distress, including the steps of providing a warning device and location carried by the user, containing a first module GPS type location adapted to provide the position of the user; causing said device to detect a distress situation; causing said device to automatically emit an alert signal containing the position of the user in distress; receiving the alert signal at a monitoring device; and searching for the user by means of a second GPS location module having the same characteristics as the first location module.

  According to one embodiment of the invention, the monitoring device is located at a rescue center.

  According to one embodiment of the invention, the monitoring device is carried by another user.

  According to one embodiment of the invention, the alert signal contains a user identification code, the method comprising the steps of storing, beforehand, at the emergency center level, information associated with the code. identification of the user; providing the information upon receipt of the alert signal; and search for the user from the information provided.

  According to one embodiment of the invention, the alert signal is transmitted over a radio link, said alert signal being relayed to the monitoring device by at least one radio station.

  According to one embodiment of the invention, the determination by the alerting and locating device of a distress situation comprises the steps, performed at the level of the alerting and locating device, of determining whether the inclination of the user relative to the vertical is greater than a given inclination; to determine, if so, whether the user is stationary; to determine, if so, the oxygen saturation rate of the hemoglobin of the blood of the user and the heart rate of the user; and to emit, when the hemoglobin oxygen saturation rate of the user's blood is lower than a given rate, or when the oxygen saturation rate of the user's blood hemoglobin is greater than the rate given and that the heart rate of the user is lower than a given heart rate, the alert signal in the absence of a manual interruption of the user for a given duration.

  The present invention also provides an alerting device and location to be worn by a user, for the implementation of the previously described method, comprising a location module of the GPS type adapted to provide the position of the user; a transceiver adapted to transmit / receive signals remotely; at least one sensor adapted to provide a signal representative of the user's situation; a control module adapted to receive the position provided by the location module, to determine, from the representative signal supplied by the sensor, if the user is in a distress situation, and to cause the transceiver to transmit an alert signal containing the position of the user in distress; and a battery supplying the components of the alerting and locating device.

  According to one embodiment of the invention, the device comprises manual actuation means adapted to interrupt the transmission of the warning signal or to force the transmission of the warning signal.

  The present invention also provides an alerting and localization system for implementing the previously described method, comprising an alerting and localization device intended to be worn by a user, the device comprising a first location module of the type GPS adapted to provide the position of the user; a transceiver adapted to transmit / receive signals remotely; at least one sensor adapted to provide a signal representative of the user's situation; a control module adapted to receive the position provided by the first location module, to be determined, from the representative signal supplied by the sensor, if the user is in a distress situation, and to cause the transmitter / receiver to issue an alert signal containing the position of the user in distress; and a battery supplying the components of the alerting and locating device; the system further comprising a monitoring device adapted to receive the alert signal; and a user search device comprising a second GPS location module having the same characteristics as the first location module.

  According to one embodiment of the invention, the system further comprises at least one radio station adapted to receive the alert signal and to relay the alert signal to the monitoring device.

Brief description of the drawings

  These and other objects, features, and advantages of the present invention will be set forth in detail in the following description of a particular nonlimiting exemplary embodiment with reference to the accompanying figures in which: FIG. schematically an embodiment of the alerting and locating system according to the invention; Figure 2 shows in greater detail a part of the system of Figure 1; and FIG. 3 represents a method for automatically determining a distress situation according to the invention. DETAILED DESCRIPTION For the sake of clarity, the same elements have been designated with the same references in the various figures.

  Figures 1 and 2 show an embodiment of the alerting and locating system 10 according to the invention.

  The system 10 comprises a communication network in a given geographical region, comprising several radio relay stations 11 and one or more fixed monitoring devices 12, each fixed monitoring device 12 being located at a backup center 13. As a for example, the radio relay stations 11 are distributed in a mountainous region at risk of avalanches of snow. Each relay station 11 is intended to cover part of the geographical area to be monitored and is connected, for example by radio link, to one of the fixed monitoring devices 12.

  A user 14 traveling in the region covered by the relay stations 11 is equipped with a mobile alerting and locating device 15 according to the invention. The mobile device 15 comprises a GPS location module 16 connected to a GPS antenna 18 receiving signals emitted by satellites of the global capacity locating device. The locating module 16 is adapted to determine the position of the user 14 from the signals received by the GPS antenna 18. In a conventional manner, with the GPS systems currently marketed, the accuracy of the position thus determined is the same. order of a hundred meters. The mobile device 15 comprises a control module 20 receiving signals provided by sensors 22 and adapted to determine, from such signals, whether the user is in a distress situation. The sensors 22, or some of them, can transmit signals to the control module 20 via a remote link. The control module 20 is connected to a radio transmitter / receiver 24 adapted to receive and transmit radio signals via a radio antenna 26. In addition, the control module 20 is connected to the location module 16. When a distress situation is detected, the control module 20 is adapted to control the radio transmitter / receiver 24 to send an alert signal to a rescue center 13 by radio link, possibly via a relay station 11 if this is necessary, communicating all information necessary for the rescue, among others, the position of the user 14 in distress.

  A manual control 28 is connected to the control module 20 and allows the user 14 to manually activate the transmission of an alert signal or to manually interrupt the transmission of an alert signal. The control module 20 is connected to a display 30, for example a liquid crystal display, and to a buzzer 32 to indicate the operating status of the mobile device 15 to the user 14. The various components of the mobile device 15 are powered by a battery 34.

  The relay stations 11 are arranged at the level of the geographical region to be covered so that the user 14 equipped with the mobile device 15 is permanently in radio range of at least one relay station 11. The fixed monitoring device 12 of each center 13 comprises a transmitter / receiver 40 adapted to receive or transmit radio signals via a radio antenna 42. A processing module 44 is connected to the transmitter / receiver 40 and performs a processing of signals received by the transmitter / receiver 40 and controls the transmitter / receiver 40 for the transmission of particular radio signals. The processing module 44 is connected to a user interface module 45 enabling an operator to monitor and act on the information transmitted over the radio. Each user 14 having a mobile alert and location device 15 according to the invention is assigned an identification code. The identification codes are accessible to the rescue centers 13, for example via the Internet, and with each identification code are stored data that may be useful during the rescue operation, for example medical data. It is also data concerning the technical characteristics of the GPS location module 16 of the mobile device 15 held by the user. Such data can be completed by each user, for example via the Internet.

  An exemplary alerting and locating method 10 according to the invention will now be described.

  As soon as the mobile device 15 of a user 14 is turned on, the location module 16 determines at regular intervals the position of the user 14. The position of the user 14 and data concerning the quality of the position can be 30. In parallel, information concerning the operating state of the mobile device 15, for example the state of charge of the battery 34, can be permanently displayed on the display 30.

  At regular intervals, the control module 20 checks whether a radio link can be established, directly or indirectly, with a fixed monitoring device 12. To do this, the control module determines whether a radio link can be established with a relay station. 11, a relay station 11 possibly corresponding in the following explanation to a fixed monitoring device 12. First, the control module 20 determines which relay stations 11 are closest to the user 14 from the position provided by the locator module 16. To do this, the positions of the relay stations 11 can be stored at the control module 20. According to the present embodiment, each relay station 11 can receive radio signals modulated at a frequency receiving frequency, the reception frequency being different for each relay station 11, and each relay station 11 may transmit s radio signals modulated at a given transmission frequency, the transmission frequency being different for each relay station 11. The radio transmitter / receiver 24 is therefore controlled to transmit, via the radio antenna 26, a modulated request signal at the reception frequency of the nearest relay station 11. If the nearest relay station 11 is operational, the transceiver 24 will detect the opening of the relay station 11 by detecting the transmission carrier of said relay station 11. Upon receipt of this confirmation signal of the availability of the relay station 11, the control module 20 stores in memory an identifier of the relay station 11 closest considered operational. In the case where the mobile device 15 does not receive an availability confirmation signal from the nearest relay station 11, it transmits a request signal to the second closest relay station 11 and, in the absence of receiving an availability confirmation signal, successively to relay stations 11 more and more distant until receiving a confirmation of availability signal from a relay station 11 questioned. The control module 20 then stores in memory an identifier of the relay station 11 having sent an availability confirmation signal. If no relay station 11 responds to the mobile device 15, the control module 20 keeps in memory the fact that no relay station 11 is operational. The presence or absence of an operational relay station 11 may be indicated on the display 30.

  At the same time, as soon as the mobile device 15 is turned on, the control module 20 periodically determines whether the user 14 is in a distress situation from the analysis of the signals supplied by the sensors 22. Determination of distress situation is described in more detail later. In the case where a distress situation is detected, the module 20 controls the transmitter / receiver 24 so as to emit a modulated warning signal at the reception frequency of the last relay station 11 considered to be operational, and which, as this has been indicated previously, may correspond to a fixed surveillance device 12. For example, the alert signal is a digital signal comprising a code indicating the distress situation, the identification code of the user, and the position of the user (eg the latitude and longitude of the user as provided by the location module 16). In the case where no relay station 11 has transmitted to the mobile device 15 of availability confirmation signal, the alert signal is transmitted at a given frequency called common frequency. The warning signal is emitted at regular intervals by the mobile device 15.

  On receipt of the alert signal (relayed if necessary by a relay station 11), the processing module 44 of the fixed monitoring device 12 located at the emergency center 13 triggers the alert, for example, by sounding an audible signal through the user interface module 45. From the identification code of the user 14 contained in the alert signal, the rescuer can obtain relevant information, for example of a medical nature, making it possible to prepare adapted relief. In addition, the fixed monitoring device 12 transmits an acknowledgment signal to the mobile device 15 indicating that the warning signal has been received and recorded by the fixed monitoring device 12. On receipt of the acknowledgment signal, the control module 20 of the mobile device 15 interrupts the periodic transmission of the warning signal.

  The rescue center 13 sends a rescue team 46 to the user's position indicated in the alert signal. However, as indicated above, the accuracy of a position provided by the GPS location module 16 is of the order of one hundred meters. In order to locate the user 14 with greater accuracy, the rescue team 46 has a mobile device 15 having the same technical characteristics as the mobile device 15 of the user in distress 14. The technical characteristics of the module GPS location 16 of the mobile device 15 of the rescue team 46 are therefore identical to the characteristics of the GPS location module 16 contained in the mobile device 15 of the distressed user 14. Two GPS location modules, each having accuracy of the order of one hundred meters, having the same technical characteristics and being in the same geographical area provide, at the same time, a comparison of their respective position with a precision less than one meter. Therefore, even if the absolute position of the user 14 remains inaccurate, the rescue team 46, using the same mobile device 15 as the distressed user 14 and moving towards the position indicated in the signal d alert, arrives directly to the precise location where the user 14 in distress.

  In addition, in order to refine the location of the user 14 in distress, the mobile device 15 of the rescue team 46 transmits, at regular intervals, a signal requesting the mobile device 15 of the user 14 of the transmit the last update of the position calculated by its GPS location module 16. If the GPS location module 16 of the mobile device 15 of the user 14 is unable to provide an updated position, the mobile device 15 of the user 14 sends a specific signal indicating to the mobile device 15 of the rescue team 46 that the position to be taken into account is the last valid position issued. If the mobile device 15 of the emergency team 46 is out of range of the mobile device 15 of the distressed user 14, the communication between the two mobile devices is via the fixed monitoring device 12 until the rescue team 46 is sufficiently close to the user 14 in distress so that the two mobile devices 15 are within radio range and can communicate live.

  Further, when the mobile device 15 of the rescue team 46 is used to search for a user 14 in distress (as in the case described above), the display 30 of the mobile device 15 can be used to provide a proper visual interface. to simplify searches. For example, it can be displayed in search mode, an arrow indicating the direction to be followed and the distance between the rescue team 46 of the user 14 to rescue.

  The alerting and locating method has been described in the case of an automatic transmission of an alert signal by the mobile device 15 when the user 14 is in a distress situation. However, the user 14 can voluntarily cause the mobile device 15 to emit an alert signal, for example by actuating the manual control 28.

  Advantageously, the relay stations 11 may correspond to the radio stations of the security networks used for example by the emergency professionals who cover all the mountainous regions of France. Such radio stations are adapted to receive modulated radio signals on a reception frequency specific to each radio station and to emit signals modulated on a transmission frequency specific to each radio station. The transmission and reception frequencies of such radio stations are in the 150 MHz band. As a result, the present invention simply requires equipping the operational centers with the rescue professionals with fixed monitoring devices 12 and the mobile alerting device first responders 15.

  For such an exemplary embodiment, the transmission of the signals between the mobile device 15 and the fixed monitoring device 12, possibly via the relay stations 11, can implement a frequency modulation of the MSK type according to the French standard AN1382 describing the frequencies modulation used for the binary coding as well as the frames necessary for the opening and closing of the relays in the case where the radio network is secure.

  In order to implement the present invention with the existing network of radio stations of the high mountain gendarmerie platoon and to ensure that a signal received by a radio station can be correctly demodulated to provide the warning signal, it is necessary to that the mobile device 15 emits with a transmission power of the order of 5 Watts.

  According to a variant of the present invention, the transmission of signals between the mobile device 15 and a backup center 13 can implement the global system of mobile communications or GSM (acronym for Global System for Mobile Communications) or a satellite communication .

  The mobile device 15 can emit, parallel to the transmission of an alert signal modulated at the reception frequency of a relay station 11, the same warning signal modulated at the common frequency. The common frequency modulated alert signal may be received by another mobile device held by another user located sufficiently close to the user 14 in distress. In particular, in the case where the mobile device 15 of the user 14 in distress can not communicate with any relay station 11, the alert signal is transmitted only at the common frequency. In this case, the other user having received the common frequency modulated warning signal can, if he can, use his mobile device 15, under the same conditions as the rescue team 46 (as described above). previously) to rescue the user 14 in distress. In addition, if the mobile device 15 of the other user is itself under cover of the radio network, the alert is automatically relayed to the fixed monitoring device 12.

  FIG. 2 represents an exemplary embodiment of the method for determining a distress situation implemented at the level of the control module 20.

  In the present exemplary embodiment, the sensors 22 used for the determination of a distress situation comprise: an inclinometer providing a signal representative of the user's inclination 14, for example the inclination of the user's torso 14, with respect to the vertical; a motion sensor, for example an inertial sensor, providing a signal representative of the mobile or immobile state of the user 14; and a pulse oximeter, for example of the type marketed by the companies Nellcor, Masimo, and Sentec, from which the user's heart rate 14 and the saturation (SpO2) oxygen level of the hemoglobin of the patient can be determined. blood of the user 14.

  In step 50 of the method for determining a distress situation according to the invention, the control module 20 receives the signal supplied by the inclinometer and determines the inclination of the user 14 relative to the vertical. In step 52, the control module 20 compares the determined inclination with a reference inclination, for example 45.

  If the inclination with respect to the vertical is less than 45, indicating that the user 14 is more or less in the upright position, the process proceeds to step 54 at which an expectation of a determined duration is realized, for example of the order of 10 seconds. The process then returns to step 50 for the acquisition of a new signal provided by the inclinometer. In the present embodiment, it is therefore considered that a user 14 more or less standing is not in a situation of distress.

  In step 52, if the inclination with respect to the vertical is greater than 45, the method continues at a step 54 at which the control module 20 acquires the signal provided by the motion sensor. In step 58, the control module 20 determines whether the user 14 is stationary or in motion. If the user 14 is moving, the process proceeds to step 54, before restarting an acquisition cycle in step 50. In the present embodiment, it is therefore considered that a user 14 in motion is not in a distress situation. If in step 58, the control module 20 determines that the user 14

  is stationary, the method continues in step 60 at which the control module 20 determines the user's heart rate 14 and the oxygen saturation rate (SpO2) of the blood hemoglobin of the user 14 from the signal provided by the pulse oximeter. The process continues at step 62 at which the oxygen saturation rate is compared to a reference saturation rate SpO2ref. If the saturation rate is lower than the reference rate, meaning that the blood of the user 14 is insufficiently oxygenated, a distress situation is detected and the process continues in step 64 at which the module 20 controls the emission of an audible signal via the buzzer 32, and / or the display of a specific image at the display 30 so as to warn the user of the imminence of the sending of an alert signal. The method continues in step 66 at which the control module 20 waits, for example for about ten seconds, an action of the user 14. Indeed, if the user 14 is not in a situation of distress it can, for example by means of the manual control 28, interrupt the process which then returns to step 54. If during the waiting period of: Step 66, the user 14 does not perform any action, the method continues in step 68 at which the module 20 controls the transmitter / receiver 24 for the transmission of an alert signal, as described above.

  If in step 62, the determined oxygen saturation rate is greater than the SpO2ref reference rate, the process proceeds to step 70 at which the control module 20 compares the user's heart rate 14, determined at step 60, a reference heart rate. If the determined heart rate is below a reference heart rate, indicating the imminence of cardiac arrest or malaise, the method continues at step 64 to trigger an alert. If the determined heart rate is higher than the reference heart rate, the method continues in step 72 at which the control module 20 analyzes the recent changes in heart rate, for example by comparing the last determined heart rate values. . If an increase in heart rate occurs, indicating for example a malaise situation, the process continues at step 64 to trigger an alert. If no increase in heart rate is observed, the process returns to standby 54 to restart an acquisition cycle in step 50.

  The present invention has many advantages: first, the present invention allows a precise location of a person 14 in distress through the use of a GPS location module 16 which provides relatively inaccurate position information. Indeed, the rescue team 46 using a GPS location module 16 having the same technical characteristics as the GPS location module 16 of the mobile device 15 of the person 14 in distress, the two GPS location modules 16 provide data of position with substantially the same type of error, thus allowing the rescue team 46 to quickly find the user 14 in distress. By location modules having identical technical characteristics is meant two location modules having components of the same nature and implementing similar position determination and position correction algorithms. However, the present invention can also be implemented with GPS location modules implementing different position determination and correction algorithms. In this case, even if the accuracy of the difference between the positions provided by the locating module 16 of the rescue team 46 and the locating module 16 of the person 14 in distress may be greater than one meter, it is nevertheless better as the accuracy of the position provided by the one and the other GPS location module.

  Secondly, the present invention makes it possible to implement a method for alerting and locating a person 14 in distress in which the transmission of the alert signal from the mobile device carried by the distressed person can put an already existing communication network. Advantageously, such a communication network may correspond to the radio stations used by the rescue professionals, which allows the implementation of a low-cost warning and localization method and effectively covering large geographical areas. at risk".

  Third, the present invention permits the determination of a distress situation in a substantially safe manner with a minimum number of sensors.

  Of course, the present invention is susceptible of various variations and modifications which will be apparent to those skilled in the art. In particular, other sensors can be used to determine if a user is in a distress situation. By way of example, it may be an environment sensor surrounding the user, based on the Doppler effect, in which the sensor emits a wave and measures the difference in frequency and frequency. intensity between the transmitted wave and a reflected wave, which gives indications as to the nature of the immediate environment of the user and in particular indicates whether the user is surrounded by snow or water.

Claims (10)

  1. Method for alerting and locating a user (14) in a distress situation, comprising the following steps: providing a user-provided alerting and locating device (15) containing a first module GPS type location (16) adapted to provide the user's position; causing said device to detect a distress situation; causing said device to automatically emit an alert signal containing the position of the user in distress; receiving the alert signal at a monitoring device (12; 15); and searching for the user by means of a second GPS location module having the same characteristics as the first location module.   The method of claim 1, wherein the monitoring device (12) is located at a rescue center (13).   The method of claim 1, wherein the monitoring device (15) is carried by another user.   4. Method according to claim 2, wherein the alert signal contains a user identification code (14), the method comprising the following steps: store, beforehand, at the emergency center (13) information associated with the identification code of the user (14); provide the information upon receipt of the alert signal; and search the user from the information provided. 15   5. The method of claim 1, wherein the alert signal is transmitted over a radio link, said alert signal being relayed to the monitoring device (12; 15) by at least one radio station (11).   6. Method according to claim 1, wherein the determination, by the alerting and locating device (15), of a distress situation comprises the following steps, carried out at the level of the alerting and locating device: determining if the inclination of the user (14) relative to the vertical is greater than a given inclination; determine, if so, whether the user is stationary; determine, if so, the oxygen saturation rate of the user's hemoglobin blood and the user's heart rate; and emit, when the oxygen saturation rate of the hemoglobin of the user's blood is below a given rate, or when the oxygen saturation rate of the user's blood hemoglobin is greater than the given rate and that the heart rate of the user is lower than a given heart rate, the alert signal in the absence of a manual interruption of the user for a given duration.   7. An alerting and locating device (15) intended to be worn by a user (14), for carrying out the method according to claim 1, comprising: a GPS-type location module (16) adapted to provide the position of the user; a transmitter / receiver (24) adapted to transmit / receive signals remotely; at least one sensor (22) adapted to provide a signal representative of the user's situation; a control module (20) adapted to receive the position provided by the location module, to be determined, from the representative signal supplied by the sensor, if the user is in a distress situation, and to bring the transmitter / receiver to emit an alert signal containing the position of the user in distress; and a battery (34) supplying the components of the alerting and locating device.   8. Device according to claim 7, comprising a manual actuating means (28) adapted to interrupt the emission of the warning signal or to force the emission of the warning signal.   An alerting and locating system (10) for carrying out the method according to claim 1, comprising: an alerting and locating device (15) to be carried by a user (14), comprising: a first GPS location module (16) adapted to provide the position of the user; a transmitter / receiver (24) adapted to transmit / receive signals remotely; at least one sensor (22) adapted to provide a signal representative of the user's situation; a control module (20) adapted to receive the position provided by the first location module, to determine, from the representative signal supplied by the sensor, if the user is in a distress situation, and to bring the transmitter / receiver to emit an alert signal containing the position of the user in distress; and a battery (34) supplying the components of the alerting and locating device; a monitoring device (12; 15) adapted to receive the warning signal; and a user search device (15) comprising a second GPS location module having the same characteristics as the first location module.   The system of claim 9, further comprising at least one radio station (11) adapted to receive the alert signal and relay the alert signal to the monitoring device (12; 15).