Method and system for securing the wearing of at least one piece of personal protective equipment

Abstract

Method and system for securing the wearing of at least one piece of personal protective equipment The invention relates to a method for securing the wearing of at least one piece of PPE by a worker (100), each PPE being equipped with a respective slave radiofrequency beacon (120). According to such a method, a master radiofrequency beacon (130) equipping the worker in a predetermined position performs, for each slave beacon: - reception of a radiofrequency signal emitted by the slave beacon; - estimation of a power of the received signal; - estimation of a distance between the master beacon and the slave beacon from the power of the received signal; and, if the estimated distance is greater than a predetermined threshold distance associated with the slave beacon: - generation of a first alert information item. ABSTRACT FIGURE: [Fig.1]

Description

Title of the invention: Method and system for securing the wearing of at least one item of personal protective equipment Field of the invention

[0001] The field of the invention is that of worker safety.

[0002] The invention relates more particularly to the wearing of personal protective equipment, or PPE, by such a worker.

[0003] The invention thus has numerous applications in all fields of intervention of workers wearing such PPE, in particular but not exclusively, for the maintenance of industrial systems such as distribution or telecommunications networks, renewable energy generation systems, waste management systems, etc. Prior art and its drawbacks

[0004] PPE is designed to protect workers from occupational hazards, whether they are hazardous chemicals, extreme temperatures, airborne particles, excessive noise, or other potential hazards. However, despite the undeniable importance of PPE, wearing it can raise many challenges and problems.

[0005] First, there is a challenge in raising awareness among workers about the importance of wearing PPE. It is sometimes difficult to convince workers to wear it regularly, especially if it is perceived as uncomfortable or inconvenient. A poor understanding of occupational risks and potential health consequences can also lead to neglect of PPE.

[0006] In addition, the choice of PPE is a critical aspect. Workers must be trained to select the appropriate PPE based on their specific work environment and the nature of the risks to which they are exposed. Unsuitable PPE may not provide the necessary protection, which can endanger the health of workers.

[0007] There is thus a need for a technique for ensuring that a worker actually wears PPE while working. Preferably, such a technique must make it possible to ensure that the PPE worn by the worker is suitable for a given work environment. Statement of the invention

[0008] In one embodiment of the invention, a method is proposed for securing the wearing of at least one piece of personal protective equipment, hereinafter PPE, by a worker. Each PPE is equipped with a radiofrequency beacon, called a slave beacon, respective. According to such a method, a radiofrequency beacon, called a master beacon, equipping the worker in a predetermined position executes, for each slave beacon:

[0009] - reception of a radiofrequency signal emitted by the slave beacon;

[0010] - an estimate of a power of the received signal;

[0011] - an estimate of a distance between the master beacon and the slave beacon from the received signal strength; and, if the estimated distance is greater than a predetermined threshold distance associated with the slave beacon:

[0012] - a generation of a first alert information.

[0013] Thus, the invention proposes a new and inventive solution for ensuring that a worker actually wears one (or more) PPE during his work.

[0014] More particularly, the wearing of PPE equipped with a given slave beacon is controlled via the estimation of the distance between the master beacon and the given slave beacon. Thus, it is easily detected when the PPE in question is not worn by the worker.

[0015] In certain embodiments, if for each slave beacon the estimated distance is less than the predetermined threshold distance associated with the slave beacon, the master beacon executes again, for each slave beacon, said reception of a radiofrequency signal, said estimation of a power of the received signal, said estimation of a distance, and, if the new estimated distance is greater than the predetermined threshold distance associated with the slave beacon, the master beacon executes again the generation of a first alert information.

[0016] Thus, securing the wearing of the PPE (or PPEs) is carried out according to a predefined time sequence or periodically, e.g. with a period of between 0.5 seconds and 1 second so as not to miss events such as the removal of PPE and not to have latency in the generation of alerts. In this way, it can be detected when the worker removes PPE, e.g. a glove, when this is not authorized.

[0017] In some embodiments, the master beacon performs, for each slave beacon, an obtaining of the predetermined threshold distance associated with the slave beacon.

[0018] Thus, the process is optimized for a given worker and given equipment.

[0019] In some embodiments, obtaining the predetermined threshold distance associated with the slave tag includes:

[0020] - reception of a calibration radiofrequency signal emitted by the slave beacon when the respective PPE is correctly positioned on the worker;

[0021] - an estimate of a power of the received calibration signal; and

[0022] - an estimate of the predetermined threshold distance associated with the slave beacon to from the power of the received calibration signal.

[0023] In some embodiments, receiving a radio frequency signal from ca libration and estimation of a power of the received calibration signal are executed a plurality of times so as to deliver a plurality of powers of received calibration signals. The predetermined threshold distance associated with the slave beacon is estimated from an average of the powers of received calibration signals.

[0024] Thus, the estimation of the predetermined threshold distance associated with the slave beacon is more precise via the averaging effect which reduces the variance of the estimation in the presence of noise.

[0025] In some embodiments, the master tag executes, for each slave tag:

[0026] - reception of a radiofrequency identification signal emitted by the beacon slave, the identification signal comprising a predefined identifier stored in the slave tag, the predefined identifier being associated with the type of PPE that the slave tag equips;

[0027] - a transmission, to a radiofrequency beacon, called a tracking beacon, implemented in a worker's work area, of the predefined identifier stored in the slave tag, the correspondence between the predefined identifier and the associated PPE type being known to the tracking tag.

[0028] Thus, the tracking beacon is able to check that the worker is wearing the PPE (or PPE) to be used in the work area.

[0029] In some embodiments, the master tag executes:

[0030] - a reception of a second alert information sent by the tracking beacon when, for at least one expected identifier associated with a type of PPE to be worn by the worker in the work area, no predefined identifier transmitted during the execution, for each slave tag, of said transmission corresponds to the expected identifier.

[0031] In certain embodiments, the master beacon executes a sending of the first alert information and / or the second alert information to a restitution device equipping the worker.

[0032] Thus, the worker is alerted that he is not wearing expected PPE, or that he is wearing PPE of the wrong type for the work area in which he is located.

[0033] In certain embodiments, the radio frequency communication between the master beacon and the at least one slave beacon implements a radio technology belonging to the group comprising:

[0034] - a Bluetooth protocol;

[0035] - a WiFi protocol;

[0036] - a Zigbee protocol; and

[0037] - an Ultra WideBand protocol.

[0038] In some embodiments, radio frequency communication between the beacon master and tracking beacon implements group-owned radio technology including:

[0039] - a Bluetooth protocol;

[0040] - a WiFi protocol;

[0041] - a Zigbee protocol;

[0042] - an Ultra WideBand protocol; and

[0043] - a modulation called OOK.

[0044] The invention also relates to a radiofrequency beacon, called a master beacon, for securing the wearing of at least one PPE by a worker. Each PPE is equipped with a respective radiofrequency beacon, called a slave beacon. The master beacon is configured to execute, for each slave beacon and when the master beacon equips the worker in a predetermined position:

[0045] - reception of a radiofrequency signal emitted by the slave beacon;

[0046] - an estimate of a power of the received signal;

[0047] - an estimate of a distance between the master beacon and the slave beacon from the received signal strength; and, if the estimated distance is greater than a predetermined threshold distance associated with the slave beacon:

[0048] - a generation of a first alert information.

[0049] The invention also relates to a system comprising:

[0050] - a radio frequency beacon, called a master beacon, as described above; and

[0051] - at least one radiofrequency beacon, called a slave beacon, intended to equip a PPE respective. List of figures

[0052] Other aims, characteristics and advantages of the invention will appear more clearly on reading the following description, given as a simple illustrative, and non-limiting, example, in relation to the figures, among which:

[0053] [Fig. 1] illustrates a system for securing the wearing of PPE by a worker according to one embodiment of the invention;

[0054] [Fig.2] illustrates an example of the structure of a radiofrequency beacon, called a beacon slave, of the system of [Fig.l] according to an embodiment of the invention;

[0055] [Fig.3] illustrates an example of the structure of a radiofrequency beacon, called a beacon master, of the system of [Fig.l] according to an embodiment of the invention;

[0056] [Fig.4] illustrates an example of the structure of a radiofrequency beacon, called a beacon of monitoring, of the system of [Fig.l] according to an embodiment of the invention;

[0057] [Fig.5a] illustrates an analog signal representing a binary train according to a mode of realization of the invention;

[0058] [Fig.5b] illustrates a radiofrequency carrier according to an embodiment of the invention;

[0059] [Fig.5c] illustrates the signal resulting from the OOK modulation of the carrier of the [Fig.5b] by the bitstream of [Fig.5a] according to one embodiment of the invention.

[0060] [Fig.6] illustrates the steps of a process for securing the wearing of PPE by tra value implemented by the system of [Fig.l] according to an embodiment of the invention.

[0061] Detailed description of embodiments of the invention

[0062] We now present, in relation to [Fig.l], a system for securing the wearing of PPE 110a, 110b, 110c by a worker 100 according to an embodiment of the invention. For example, such PPE 110a, 110b, 110c comprise safety shoes 110a, gloves 110b and a helmet 110c.

[0063] The security system comprises a set of radiofrequency beacons 120, called slave beacons. Each slave beacon equips a respective PPE 110a, 110b, 110c. In the present embodiment, the worker 100 wears a plurality of PPEs 110a, 110b, 110c each equipped with a respective slave beacon 120. In other embodiments, the worker 100 wears a single PPE equipped with a slave beacon 120. In general, the security system, as well as the corresponding method of [Fig. 6], relates to the wearing of at least one PPE by a worker 100, each PPE being equipped with a respective slave beacon 120.

[0064] Returning to [Fig.l], the security system also comprises a radiofrequency beacon 130, called master beacon, equipping the worker 100 in a predetermined position. The fact that the master beacon 130 is placed in a predetermined position allows, for each slave beacon 120, a comparison between, on the one hand, the estimated distance between the master beacon 130 and the slave beacon 120 considered and, on the other hand, a predetermined threshold distance associated with the slave beacon 120 considered. Such a comparison is more particularly described below in relation to [Fig.5].

[0065] Returning to [Fig.l], the security system also comprises a radiofrequency beacon 150, called a tracking beacon, implemented in a work area 160 of the worker 100 (e.g. a warehouse, a given workstation, a construction site). Such a tracking beacon 150 makes it possible in particular to check that the worker 100 is wearing the PPE 110a, 110b, 110c to be used in the work area 160. However, in other embodiments the security system does not comprise a tracking beacon 150. In such cases, the security system only comprises a master beacon 130 equipping the worker 100 in a predetermined position and one (or more) slave beacons 120 equipping a respective PPE 110a, 110b, 110c.

[0066] Returning to [Fig.l], the security system also comprises a restitution device 140. Such a restitution device 140 comprises means (e.g. a radio frequency transceiver or a wired link) making it possible to communicate with the master beacon 130 so as to receive one (or more) alert information. restitution device 140 also comprises restitution means (e.g. a loudspeaker, a screen, a light device) to the worker 100 of the alert information (or information). However, in other embodiments the security system does not comprise a restitution device 140. The alerts generated by the master beacon 130 are for example sent to a remote device, e.g. to inform a manager of the worker 100.

[0067] We now present, in relation to [Fig.2], an example of a slave beacon structure 120 comprising means making it possible to implement all or part of the corresponding steps of the securing method of [Fig.6] according to an embodiment of the invention.

[0068] More particularly, such a slave tag 120 comprises different means such as a random access memory 203 (for example a RAM memory), a processing unit 202 equipped for example with a processor, and controlled by a computer program stored in a read-only memory 201 (for example a ROM memory or a hard disk). Upon initialization, the code instructions of the computer program are for example loaded into the random access memory 203 before being executed by the processor of the processing unit 202.

[0069] The slave beacon 120 further comprises an on-board electrical energy source 205 (e.g. a battery, rechargeable or not) and radio frequency communication means 204, e.g. a transmitter / receiver implementing a protocol of the Bluetooth, Zigbee or UWB (for “Ultra WideBand” in English) type. Such communication means 204 allow communication e.g. with the master beacon 130.

[0070] This [Fig.2] illustrates only one particular way, among several possible ones, of producing the slave tag 120 so that it performs all or part of the corresponding steps of the securing method of [Fig.6] (according to any one of the embodiments and / or variants described below in relation to [Fig.6]). For example, these steps can be performed indifferently by implementing a reprogrammable computing machine (a PC computer, a DSP processor or a microcontroller) executing a program comprising a sequence of instructions, or by implementing a dedicated computing machine (for example a set of logic gates such as an FPGA or an ASIC, or any other hardware module).

[0071] In the case where the slave tag 120 is produced by implementing a reprogrammable computing machine, the corresponding program (i.e. the sequence of instructions) may be stored in a removable storage medium (such as for example a CD-ROM, a DVD-ROM, a USB key) or not, this storage medium being partially or totally readable by a computer or a processor.

[0072] We now present, in relation to [Fig.3], an example of a tag structure master 130 comprising means making it possible to implement all or part of the corresponding steps of the securing method of [Fig.6] according to an embodiment of the invention.

[0073] More particularly, such a master tag 130 comprises different means such as a random access memory 303 (for example a RAM memory), a processing unit 302 equipped for example with a processor, and controlled by a computer program stored in a read-only memory 301 (for example a ROM memory or a hard disk). At initialization, the code instructions of the computer program are for example loaded into the random access memory 303 before being executed by the processor of the processing unit 302.

[0074] The master beacon 130 further comprises an on-board electrical energy source 305 (e.g. a battery, rechargeable or not) and radio frequency communication means 304, e.g. a transmitter / receiver implementing a protocol of the Bluetooth, WiFi, Zigbee or UWB (for “Ultra WideBand” in English) type. Such communication means 204 allow communication e.g. with the slave beacon(s) 120 and with the tracking beacon 150. In certain embodiments, in order to communicate with the tracking beacon 150, the radio frequency communication means 304 implement a so-called all-or-nothing modulation, or OOK (for “On-Off Keying” in English). More particularly, according to such a modulation, an analog signal representing a binary train ([Fig.5a]) modulates the amplitude of a radio frequency carrier ([Fig.5b]) in all-or-nothing mode.For example, a low-state information bit (logical "0") corresponds to a substantially zero amplitude of the carrier while a high-state information bit (logical "1") corresponds to a non-zero predetermined value amplitude of the carrier ([Fig.5c]).

[0075] [Fig. 3] illustrates only one particular way, among several possible ways, of producing the master tag 130 so that it performs all or part of the corresponding steps of the securing method of [Fig. 6] (according to any one of the embodiments and / or variants described below in relation to [Fig. 6]). For example, these steps can be performed indifferently by implementing a reprogrammable computing machine (a PC computer, a DSP processor or a microcontroller) executing a program comprising a sequence of instructions, or by implementing a dedicated computing machine (for example a set of logic gates such as an FPGA or an ASIC, or any other hardware module).

[0076] In the case where the master tag 130 is produced by implementing a reprogrammable computing machine, the corresponding program (i.e. the sequence of instructions) may be stored in a removable storage medium (such as for example a CD-ROM, a DVD-ROM, a USB key) or not, this storage medium being partially or totally readable by a computer or processor.

[0077] We now present, in relation to [Fig.4], an example of a tracking beacon structure 150 comprising means making it possible to implement all or part of the corresponding steps of the securing method of [Fig.6] according to an embodiment of the invention.

[0078] More particularly, such a tracking beacon 150 comprises various means such as a random access memory 403 (for example a RAM memory), a processing unit 402 equipped for example with a processor, and controlled by a computer program stored in a read-only memory 401 (for example a ROM memory or a hard disk). Upon initialization, the code instructions of the computer program are for example loaded into the random access memory 403 before being executed by the processor of the processing unit 402.

[0079] The tracking beacon 150 further comprises an on-board electrical energy source 405 (e.g. a battery, rechargeable or not) and radio frequency communication means 404, e.g. a transmitter / receiver implementing a protocol of the Bluetooth, WiFi, Zigbee or UWB (for “Ultra WideBand” in English) type. Such communication means 404 allow communication e.g. with the master beacon 130. In certain embodiments, the communication means 404 implement a so-called all-or-nothing modulation, or OOK (for “On-Off Keying”), as described above.

[0080] [Fig. 4] illustrates only one particular way, among several possible ways, of producing the tracking beacon 150 so that it performs all or part of the corresponding steps of the securing method of [Fig. 6] (according to any one of the embodiments and / or variants described below in relation to [Fig. 6]). For example, these steps can be performed indifferently by implementing a reprogrammable computing machine (a PC computer, a DSP processor or a microcontroller) executing a program comprising a sequence of instructions, or by implementing a dedicated computing machine (for example a set of logic gates such as an FPGA or an ASIC, or any other hardware module).

[0081] In the case where the tracking beacon 150 is produced by implementing a reprogrammable computing machine, the corresponding program (i.e. the sequence of instructions) may be stored in a removable storage medium (such as for example a CD-ROM, a DVD-ROM, a USB key) or not, this storage medium being partially or totally readable by a computer or a processor.

[0082] We now present, in relation to [Fig. 6], the steps of a method for securing the wearing of PPE 110a, 110b, 110c implemented by the system of [Fig. 1] according to an embodiment of the invention.

[0083] According to such a method, the master tag 130 executes, for each slave tag 120, a step E600 of obtaining a predetermined threshold distance associated with the slave beacon 120 considered. More particularly, such a predetermined threshold distance is representative of the radioelectric distance between the master beacon 130 and the slave beacon 120 considered when the corresponding PPE 110a is correctly positioned on the worker 100. The predetermined threshold distance can thus be interpreted as a metric making it possible to decide whether the PPE 110a, 110b, 110c in question is actually correctly positioned on the worker 100.

[0084] In some embodiments, obtaining the predetermined threshold distance associated with a given slave beacon 120 comprises the following steps performed by the master beacon 130:

[0085] - reception of a calibration radiofrequency signal emitted by the slave beacon 120 considered when the corresponding PPE 110a, 110b, 110c is correctly positioned on the worker 100;

[0086] - an estimate of a power of the received calibration signal; and

[0087] - an estimate of the predetermined threshold distance associated with the slave beacon 120 considered from the power of the received calibration signal.

[0088] For example, the correspondence between the predetermined threshold distance D and the power Pr of the received calibration signal is given by the equation [Math.l] when the powers are expressed in logarithmic units:

[0089] [Math.l] D_ 10W))

[0090] Where Pe represents the transmission power of the slave beacon 120 considered and N a constant which depends on the radioelectric propagation medium (eg N —2 for vacuum).

[0091] In certain embodiments, the steps of receiving a calibration radiofrequency signal and estimating a power of the received calibration signal are executed a plurality of times so as to deliver a plurality of powers of received calibration signals. The predetermined threshold distance associated with the slave beacon 120 considered is then estimated from an average of the powers of received calibration signals.

[0092] Thus, the estimation of the predetermined threshold distance associated with the slave beacon 120 considered is more precise via the averaging effect which reduces the variance of the estimation in the presence of noise.

[0093] In other embodiments, the predetermined threshold distance associated with a given slave beacon 120 is obtained by other techniques, e.g. on the basis of estimates made from a worker model, or from electromagnetic simulations.

[0094] Returning to [Fig.6], the master tag 130 executes, for each slave tag 120:

[0095] - a step E610 of receiving a radiofrequency signal emitted by the slave beacon 120 considered. The radiofrequency signal in question is identified by the master beacon 130 as being emitted by the slave beacon 120 considered. For example, the radiofrequency signal in question comprises an identifier of the slave beacon 120 considered. Alternatively, a communications channel between the master beacon 130 and the slave beacon 120 considered is previously established according to a given radio protocol;

[0096] - a step E620 of estimating a power of the received signal;

[0097] - a step E630 of estimating a distance between the master beacon 130 and the beacon slave 120 considered from the power of the received signal; and, if the estimated distance is greater than the predetermined threshold distance associated with the slave beacon 120 considered:

[0098] - a step E640 of generating a first alert information.

[0099] For example, during step E630, the distance between the master beacon 130 and the beacon slave 120 considered is estimated by implementing the same steps as those described above in relation to step E600 of obtaining a predetermined threshold distance associated with the slave beacon 120 considered (eg by implementing the equation [Math.l] and possibly an averaging).

[0100] In the embodiment of [Fig.6], the predetermined threshold distance associated with the slave beacon 120 considered is the threshold distance determined during the execution of the aforementioned step E600.

[0101] However, in certain embodiments, step E600 is not executed and the predetermined threshold distance associated with the slave beacon 120 considered is a threshold distance previously configured e.g. on the basis of previous implementations of step E600.

[0102] Regardless of the method of obtaining the predetermined threshold distance associated with a given slave beacon 120, the wearing of a PPE 110a, 110b, 110c equipped with such a slave beacon 120 is controlled via the estimation of the distance between the master beacon 130 and the given slave beacon 120. Thus, it is easily detected if one (or more) PPE 110a, 110b, 110c is not worn by the worker 100. The present technique thus makes it possible to ensure that the worker 100 actually wears one (or more) PPE 110a, 110b, 110c during his work.

[0103] Returning to [Fig.6], if for each slave beacon 120 the estimated distance is less than the predetermined threshold distance associated with the slave beacon 120 in question, the master beacon 130 executes again, for each slave beacon 120: the step E610 of receiving a radiofrequency signal, the step E620 of estimating a power of the received signal, the step E630 of estimating a distance between the master beacon 130 and the slave beacon 120 considered. If the new estimated distance is greater than the predetermined threshold distance associated with the slave beacon 120 considered, the beacon master 130 again executes step E640 of generating a first alert information.

[0104] Thus, securing the wearing of PPE 110a, 110b, 110c is carried out according to a predefined time sequence or periodically, e.g. with a period of between 0.5 seconds and 1 second. This makes it possible, for example, not to miss events such as the removal of PPE and also to avoid latency in the generation of alerts. In this way, it can be detected when the worker 100 removes PPE 110a, 110b, 110c, e.g. a glove, during his work when this is not authorized.

[0105] In the embodiment of [Fig.6], the master tag 130 executes, for each slave tag 120:

[0106] - a step E650 of receiving a radiofrequency identification signal emitted by the slave tag 120 considered. The identification signal comprises a predefined PPE type identifier stored in the slave tag 120 considered. The predefined PPE type identifier being associated with the type of PPE 110a, 110b, 110c that the slave tag 120 considered equips. For example, such a PPE type identifier can take a first value associated with the “glove” type, a second value associated with the “safety shoe” type, a third value associated with the “helmet” type, etc. The PPE type identifier is for example programmed in the slave tag 120 at the time of its implementation in the corresponding PPE 110a, 110b, 110c or at the time of a calibration phase of the overall system;

[0107] - a transmission step E660, to the tracking beacon 150 implemented in the zone 160 of work, of the predefined PPE type identifier stored in the slave tag 120 considered.

[0108] The correspondence between the predefined PPE type identifier and the associated PPE type 110a, 110b, 110c is known to the tracking tag 150.

[0109] Thus, the tracking beacon 150 is able to check that the worker 100 is wearing the PPE 110a, 110b, 110c to be used in the work zone 160. To do this, the tracking beacon 150 performs eg a comparison of the predefined PPE type identifier transmitted by the master beacon 130 with one (or more) expected identifiers corresponding to the types of PPE to be worn in the work zone 160 in which the tracking beacon 150 is implemented.

[0110] For example, when, for at least one expected identifier associated with a type of PPE to be worn in the work area 160, no predefined identifier transmitted by the master tag 130 during the execution, for each slave tag 120, of the transmission step E660 corresponds to the expected identifier, the tracking tag 150 generates a second alert information. To do this, the tracking tag 150 eg compares, to a predetermined list of expected identifiers of types of PPE to be worn in the work area 160, each predefined identifier received during the execution of step E660. The tracking beacon 150 detects, for each expected identifier, whether a predefined identifier received during the execution of step E660 corresponds to the expected identifier. For example, if for at least one expected identifier, no predefined identifier received during the execution of step E660 corresponds to the expected identifier in question, the tracking beacon 150 generates the second alert information, eg after a predetermined time duration.

[0111] In this case, during a step E670, the tracking beacon 150 transmits the second alert information to the master beacon 130. Conversely, during the step E670, the master beacon 130 receives the second alert information.

[0112] However, in other embodiments, steps E650, E660 and E670 are not implemented, eg when the work area 160 does not include a tracking beacon 150 as described above in relation to [Fig.l].

[0113] Returning to [Fig.6], during a step E680, the master beacon 130 executes a sending of the first alert information and / or the second alert information to the restitution device 140 equipping the worker 100.

[0114] Thus, the worker 100 is alerted that he is not wearing one (or more) PPE 110a, 110b, 110c, or that he is wearing one (or more) PPE 110a, 110b, 110c of the wrong type for the work zone 160 in which he is located.

[0115] In certain embodiments described above in relation to [Fig.l] in which the security system does not comprise a restitution device 140, step E680 is not necessarily implemented. For example, the alert information (or information) is stored in the master tag 130 in order to generate a history of the problems that have occurred, e.g. for post-processing purposes. Alternatively, during step E680 the master tag 130 sends the alert information (or information) to a remote device, e.g. to inform a manager of the worker 100.

[0116] In certain embodiments, the radio frequency communication between the master beacon 130 and the slave beacon(s) 120 implements a radio technology belonging to the group comprising: a Bluetooth protocol, a WiFi protocol, a Zigbee protocol and a UWB protocol.

[0117] In certain embodiments, the radio frequency communication between the master beacon 130 and the tracking beacon 150 implements a radio technology belonging to the group comprising: a Bluetooth protocol, a WiFi protocol, a Zigbee protocol, a UWB protocol and a so-called OOK modulation as described above.

Claims

Claims

1. Method for securing the wearing of at least one piece of personal protective equipment (110a, 110b, 110c), hereinafter PPE, by a worker (100), each PPE being equipped with a respective radiofrequency beacon (120), called a slave beacon, characterized in that a radiofrequency beacon (130), called a master beacon, equipping the worker in a predetermined position performs, for each slave beacon: - a reception (E610) of a radiofrequency signal emitted by the slave beacon; - an estimation (E620) of a power of the received signal; - an estimation (E630) of a distance between the master beacon and the slave beacon from the power of the received signal; and, if the estimated distance is greater than a predetermined threshold distance associated with the slave beacon: - a generation (E640) of a first alert information.

2. Method according to claim 1, in which, if for each slave beacon the estimated distance is less than the predetermined threshold distance associated with the slave beacon, the master beacon executes again, for each slave beacon, said reception of a radiofrequency signal, said estimation of a power of the received signal, said estimation of a distance, and, if the new estimated distance is greater than the predetermined threshold distance associated with the slave beacon, the master beacon executes again the generation of a first alert information.

3. Method according to claim 1 or 2, in which the master beacon executes, for each slave beacon: - obtaining (E600) the predetermined threshold distance associated with the slave beacon.

4. The method of claim 3, wherein obtaining the predetermined threshold distance associated with the slave beacon comprises: - receiving a calibration radiofrequency signal emitted by the slave beacon when the respective PPE is correctly positioned on the worker; - estimating a power of the received calibration signal; and - estimating the predetermined threshold distance associated with the slave beacon from the power of the received calibration signal.

5. The method of claim 4, wherein said receiving a calibration radiofrequency signal and said estimation of a power of the received calibration signal are executed a plurality of times so as to deliver a plurality of powers of received calibration signals, and wherein the predetermined threshold distance associated with the slave beacon is estimated from an average of the powers of received calibration signals.

6. Method according to any one of claims 1 to 5, in which the master tag executes, for each slave tag: - a reception (E650) of a radiofrequency identification signal emitted by the slave tag, the identification signal comprising a predefined identifier stored in the slave tag, the predefined identifier being associated with the type of PPE that the slave tag equips; - a transmission (E660), to a radiofrequency tag (150), called a tracking tag, implemented in a work area (160) of the worker, of the predefined identifier stored in the slave tag, the correspondence between the predefined identifier and the associated type of PPE being known to the tracking tag.

7. Method according to claim 6, in which the master beacon executes: - a reception (E670) of a second alert information sent by the tracking beacon when, for at least one expected identifier associated with a type of PPE to be worn by the worker in the work zone, no predefined identifier transmitted during the execution, for each slave beacon, of said transmission corresponds to the expected identifier.

8. Method according to any one of claims 1 to 7, in which the master beacon executes: - a sending (E680) of the first alert information and / or of the second alert information to a restitution device (140) equipping the worker.

9. Method according to any one of claims 1 to 8, in which the radio frequency communication between the master beacon and the at least one slave beacon implements a radio technology belonging to the group comprising: - a Bluetooth protocol; - a WiFi protocol; - a Zigbee protocol; and - an Ultra WideBand protocol.

10. Method according to claim 6 or 7, in which the radio frequency communication between the master beacon and the tracking beacon implements a radio technology belonging to the group comprising: - a Bluetooth protocol; - a WiFi protocol; - a Zigbee protocol; - an Ultra WideBand protocol; and - a so-called OOK modulation.

11. radiofrequency beacon (130), called master beacon, for securing the wearing of at least one piece of personal protective equipment (110a, 110b, 110c), hereinafter PPE, by a worker (100), each PPE being equipped with a respective radiofrequency beacon (120), called slave beacon, characterized in that the master beacon is configured to execute, for each slave beacon and when the master beacon equips the worker in a predetermined position: - a reception (E610) of a radiofrequency signal emitted by the slave beacon; - an estimation (E620) of a power of the received signal; - an estimation (E630) of a distance between the master beacon and the slave beacon from the power of the received signal; and, if the estimated distance is greater than a predetermined threshold distance associated with the slave beacon: - generation (E640) of a first alert information.

12. System comprising: - a radiofrequency beacon (130) according to claim 11; and - at least one radiofrequency beacon (120), called a slave beacon, intended to equip a respective PPE.

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