Patent Publication Number: US-2020282244-A1

Title: Safety harness, safety equipment comprising said harness and protection method

Description:
TECHNICAL FIELD OF THE INVENTION 
     The present invention relates to a safety harness, safety equipment comprising said harness, and a protection method. It applies to the fields of worksite safety and sports safety. 
     STATE OF THE ART 
     In the case of work at height, where wearing a safety harness is mandatory, currently the only devices known are those giving an alert if there is a fall. The prevention of accidents is therefore non-existent. The same is true for certain sports requiring a harness to be worn, such as rock-climbing and treetop adventure trails. 
     Document CN 106 492 368 and document JP 2015 196 590 are known; they relate to securing an anchorage, not harness tightening. Document US 2010/231402, which relates to detecting the wearing of a harness, is known. 
     None of the devices described in these documents make it possible to verify that a safety harness is being worn correctly by its user. 
     SUBJECT OF THE INVENTION 
     The present invention aims to remedy all or part of these drawbacks. 
     To this end, according to a first aspect, the present invention relates to a safety harness comprising at least one loop intended to wrap around part of the body of a user, which comprises:
         for at least one loop, a sensor for measuring the tightening force exerted on said loop, each measurement sensor providing a signal representative of said force;   a means for comparing the value represented by the signal supplied by at least one measurement sensor with a predetermined minimum force value; and   a means for indicating a tightening fault if, for at least one measurement sensor, the measured force is below the predetermined minimum force value.       

     Thanks to these provisions, not only is the case of a loop closing fault signaled, but also the case where a loop&#39;s tightening force is insufficient. The inventor has found that the harness wearer&#39;s life expectancy is reduced significantly when a loop&#39;s tightening force is not sufficient. The present invention therefore makes it possible to provide safety harness wearers with increased protection. 
     In some embodiments, the comparison means is configured to compare the value represented by the signal provided by at least one measurement sensor with a predetermined maximum force value, with a tightening fault being indicated by the means for indicating a tightening fault if, for at least one measurement sensor, the measured force is greater than the predetermined maximum force value. 
     Thanks to these provisions, the risks of a loop&#39;s tightening force being too great is reduced. The harness wearer is therefore protected against the risks of phlebitis. 
     In some embodiments, the harness that is the subject of the invention comprises a means for setting at least one predetermined force value. 
     Thanks to these provisions, the minimum and maximum force values can be tailored to the harness wearer, in particular to his weight, and/or to local regulations. 
     In some embodiments, at least one measurement sensor comprises an electrical switch that is open if there is no tightening force. 
     Thanks to these provisions, the harness uses no electrical power if it is not being worn. 
     In some embodiments, at least one measurement sensor comprises an electrical resistor that varies in the presence of a tightening force. 
     In some embodiments, at least one measurement sensor is a resistive force sensor or a variable-resistance conductive fabric. 
     Thanks to each of these provisions, the reliability of the measurement is increased and the electrical consumption is reduced. 
     In some embodiments, the harness that is the subject of the invention comprises a means for the remote wireless communication of an item of information representative of the state of at least one measurement sensor. 
     Thanks to these provisions:
         the user can receive a safety fault alert on a communicating terminal;   compliance with safety instructions can be tracked; and/or   a person responsible for safety can be warned of the fault concerning the safety of the user of the equipment.       

     In some embodiments, the harness that is the subject of the invention comprises at least one leg strap, a loop intended to wrap around the users thigh, and at least one sensor for measuring the tightening force on said leg strap. 
     In some embodiments, the harness that is the subject of the invention comprises at least one shoulder strap, a loop intended to wrap around the users shoulder, and at least one sensor for measuring the tightening force on said shoulder strap. 
     In some embodiments, the harness that is the subject of the invention comprises a control unit connected to at least one measurement sensor by a stitched conductive thread. 
     Thanks to each of these provisions, the detection of a safety fault is more reliable. 
     According to a second aspect, the present invention relates to an item of safety equipment comprising a harness that is the subject of the invention and a fastener for engaging a lanyard, and a sensor for detecting the engagement of the fastener with the lanyard, each engagement sensor providing a signal representative of the state of the engagement sensor, the means for indicating a tightening fault being configured to signal an engagement fault concerning the fastener. 
     In some embodiments, the fastening means for engaging the lanyard comprises a ring, a hook and a sensor for detecting the presence of the ring in the hook. 
     In some embodiments, the lanyard comprises two hooks and, on each hook, a sensor for detecting the presence of a mechanical part in said hook. 
     In some embodiments, at least one sensor for detecting presence in a hook is a sensor detecting the modulation of an electromagnetic field by said part. 
     According to a third aspect, the present invention relates to a method for protecting a user wearing a harness comprising at least one loop intended to wrap around part of the body of a user, said method comprising:
         a step of measuring, for at least one loop, the tightening force exerted on said loop;   a step of comparing the measured tightening force with a predetermined minimum force value; and   a step of signaling a tightening fault if the measured force is below the predetermined minimum force value.       

     In some embodiments, the method that is the subject of the invention also comprises:
         a step of comparing the measured tightening force with a predetermined maximum force value; and   a step of signaling a tightening fault if the measured force is greater than the predetermined maximum force value.       

     As the advantages, aims and features of this safety equipment and this method are similar to those of the harness that is the subject of the invention, they are not repeated here. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       Other advantages, aims and features of the present invention will become apparent from the description that will follow, made, as a non-limiting example, with reference to the drawings included in an appendix, in which: 
         FIG. 1  represents, in a front view, an item of safety equipment known from the state of the art; 
         FIG. 2  represents, in a front view, a particular embodiment of an item of safety equipment that is the subject of this invention; 
         FIG. 3  represents, in an enlarged partial view of  FIG. 2 , a sensor inserted into a leg strap; 
         FIG. 4  represents a response curve for a pressure sensor; 
         FIGS. 5A and 5B  represent, schematically, two electronic circuits comprising a pressure sensor; 
         FIGS. 6A and 6B  represent, schematically, effects of a voltage on a voltage sensor positioned on a shoulder strap; 
         FIGS. 7A and 7B  represent, schematically, two electronic circuits comprising a voltage sensor; 
         FIG. 8  represents, in a front view, a hook equipped with a sensor for detecting engagement on an anchorage; 
         FIG. 9  represents, schematically, an electronic circuit comprising a photoresistor; 
         FIG. 10  represents, schematically, the installation of units in a particular embodiment of an item of equipment that is the subject of the invention; and 
         FIG. 11  represents, in the form of a logical diagram, steps in an embodiment of the method that is the subject of the invention. 
     
    
    
     DESCRIPTION OF EXAMPLES OF REALIZATION OF THE INVENTION 
     The present description is given in a non-limiting way, each characteristic of an embodiment being able to be combined with any other characteristic of any other embodiment in an advantageous way. 
     It is now noted that the figures are not to scale. 
       FIG. 1  shows an item of safety equipment known from the state of the art. This equipment comprises a safety harness  20 . This harness  20  comprises several loops, formed from straps and intended to wrap around part of the body of a user:
         shoulder straps  21  and  22 ;   a belt  23  closed by a closure  24 ; and   leg straps  25  and  26 .       

     This harness is associated with a lanyard  27  ending in a snap hook  28  intended to be engaged in an anchor ring  29  forming a fastener for engaging the snap hook  28 . The lanyard  27  comprises a second snap hook, in the bottom of  FIG. 1 , intended to secure the user to a tether point or to a guardrail. 
       FIG. 1  shows the ring  29  in an abdominal position. In other types of harness, this ring  29  is in a dorsal position. 
     In an embodiment of the safety equipment that is the subject of the invention shown in  FIG. 2 , a harness  30  comprises, formed from straps, shoulder straps  31  and  32 , a belt  33  closed by a closure  34 , leg straps  35  and  36 , and a lanyard  27  ending in a snap hook  39 . Each of the leg straps  35  and  36  is equipped with a sensor  37  for measuring the tightening force. The belt  33  is equipped with a sensor  38  for measuring the tightening force on the shoulder straps. The snap hook  39  is equipped with a sensor  40  for detecting engagement on the ring  29 . This engagement sensor  40  is inserted into a second control unit  41 . A first control unit  42  has a wired connection via stitched conductive thread to the various sensors,  37 ,  38  and  40 . 
     The safety devices—sensors and control units—of the safety harness  30  make it possible to know whether this harness  30  is positioned correctly on the user&#39;s body, the loops are tightened correctly and the restraint lanyard  27  is engaged with the ring  29 . 
     Examples of realization of the safety devices are detailed with reference to  FIGS. 3 to 10 . 
     More generally, the safety harness  30  that is the subject of the invention comprises:
         at least one loop  31 ,  32 ,  33 ,  35  and/or  36  intended to wrap around part of the body of a user;   for at least one loop, a sensor  37  and/or  38  for measuring the tightening force exerted on said loop, each measurement sensor providing a signal representative of said force;   a means  42  for comparing the value represented by the signal supplied by at least one measurement sensor with a predetermined minimum force value; and   a means  42  for indicating a tightening fault if, for at least one measurement sensor, the measured force is below the predetermined minimum force value.       

     Preferably, the comparison means  42  is configured to compare the value represented by the signal provided by at least one measurement sensor with a predetermined maximum force value, with a tightening fault being indicated by the means  42  for indicating a tightening fault if, for at least one measurement sensor, the measured force is greater than the predetermined maximum force value. 
     Preferably, the harness comprises a means for setting at least one predetermined force value. 
     The means for comparing the force, signaling a tightening fault and setting force values are incorporated into the first control unit  42 , with the second unit  41  performing the detection and signaling of engagement faults concerning the fastener and/or the lanyard. For the force value comparison, the first unit  42  comprises an analog-digital converter, a memory with maximum and minimum values, and a central processing unit for processing these values. 
     Preferably, the first and second control units  41  and  42  each comprise a wireless remote communications module for the remote transmission of an item of information representative of the state of at least one sensor. Preferably, this item of information representative of the state of at least one sensor represents changes in the state of the sensors, i.e. the closing and the measurement of the tightening force of the loops and the engagement of the snap hook  39  in the ring  29 , or their loosening or disengagement, respectively. This information is received by a communicating terminal of the user and/or by a communicating terminal of a person responsible for the safety of the user. The term ‘communicating terminal’ includes in particular mobile telephones, tablets, computers, connected watches, lone worker protection (LWP) devices or lone worker alarm (LWA) devices. For clarity, an LWP or LWA is a device used by one (or more) workers “out of sight and hearing range” of other workers (e.g. in a hazardous environment, for window cleaners). It is a device that enables the emergency services to be notified if there is a problem. The call can be triggered by the LWP or LWA on a voluntary basis and/or automatically, for example in the event of the worker&#39;s loss of verticality. 
     The remote communication can use a short-range communications protocol, for example Bluetooth (registered trademark), which can be relayed by the communicating terminal utilizing a long-distance communications protocol, for example GSM (acronym of Global System for Mobile Communications). 
     The safety harness comprising the harness  30  and the lanyard  27  makes it possible to ensure that a worker working at height wears his equipment correctly (leg straps and shoulder straps tightened with a force between the two predetermined values, maximum and minimum; chest belt closed), and that the snap hook  39  of the lanyard  27  is engaged on one of the rings of the harness, for example ring  29 . Optionally, the lanyard  27  comprises a second engagement sensor to notify of a possible tethering fault. 
     Signals, for example light, sound, or vibration signals, allow the user to be notified when the connected harness or connected lanyard is used incorrectly. These data will also be available or visible on the communicating terminal. 
     Thanks to this remote communication:
         the user can receive a safety fault alert on a communicating terminal;   compliance with safety instructions can be tracked; and/or   a supervisor can be warned of the fault concerning the safety of the user of the harness.       

     The information available concerning the state of the sensors (tightening force for each measurement sensor and open/closed for each engagement sensor) can be viewed locally by visual signals as well as on a smartphone, for example, or remotely on another terminal (for example mobile telephone, tablet, personal computer, LWP lone worker protection device or connected watch). 
     To know whether the harness is correctly positioned and correctly tightened, and whether the restraint lanyard is installed between the harness and an attachment point, according to the invention, sensors are placed at different harness and lanyard locations. 
     As shown in  FIG. 3 , in some embodiments the harness  30  comprises, for at least one leg strap  56 , a sensor  37  for measuring the tightening force on said leg strap, this sensor being a pressure sensor inserted between two parallel straps  57  and  58  of a leg strap  56 . This pressure sensor  37  is, for example, an FRS (Force Sensitive Resistor) type. This sensor  37  preferably has a wired connection via stitched conductive threads to the first control unit  42 . 
     The resistance of this pressure sensor  37  varies as a function of the pressure exerted on its surface, as shown in  FIG. 4 . The measurement of the variation in electrical voltage applied to this variable resistor makes it possible to determine whether the user has tightened the leg strap sufficiently or too much, as shown in  FIGS. 5A and 5B . 
     In  FIG. 4 , curve  59  shows the relationship between the force exerted, on the x-axis, and the resistance at the terminals of the sensor measuring the tightening force, on the y-axis. If the pressure exerted is non-existent or insufficient, the sensor  37  measuring the tightening force acts as an infinite resistor (open circuit). The terminal  63  is therefore isolated from the electrical ground and no current passes, which limits electrical consumption solely to the use of the device. 
     For the tightening to be sufficient (a hand must not be able to pass between the strap and the thigh), a force of about one Newton must be exerted. A voltage of approximately 0.5 V is then measured between the terminals  62  and  64  of the sensor  37 , the electrical equivalent of a variable resistor  60  connected in series with a fixed resistor  61 , as shown in  FIGS. 5A and 5B . The use of a 10-kilohm fixed resistor  61  allows the circulating current to be limited to 0.2 mA. It is noted that this value is much lower than the first perception threshold (0.5 mA) given for the prevention of electrical hazards. 
     As shown in  FIGS. 6A and 6B , the harness  30  comprises, for at least one shoulder strap  31  or  32 , at least one sensor  38  for detecting the tightening of said shoulder strap. 
     In the embodiments shown in  FIGS. 6A and 6B , conductive fabrics  67  and  68 , positioned on straps  65  and  66  and mobile relative to each other, are used to realize the sensor  37  and/or  38  for measuring the tightening force. By evaluating the electrical continuity between these conductive fabrics, represented by the electrical resistance between these conductive fabrics, the tightening force of each shoulder strap  31  and  32  and/or of each leg strap  35  and  36  is measured. 
       FIG. 6A  represents the case in which the shoulder strap or leg strap is not tightened: the conductive fabrics  67  and  68  are not superposed and therefore are not in contact. The electrical resistance  69  of the link between the fabrics  67  and  68 , in this case equivalent to an open switch, is infinite.  FIG. 6B  represents the case in which the shoulder strap or leg strap is tightened: the conductive fabrics  67  and  68  are superposed and provide electrical continuity, their link  69  is thus equivalent to a variable resistor. 
     In some embodiments, a conductive fabric is used that is sensitive to pressure (for example, Velostat or Linqstat, registered trademarks). On each strap, this conductive fabric is stitched such that, when the corresponding shoulder strap is in place and is tightened, contact is made between two strips of conductive fabric, variable electrical resistances  70  and  74  appearing between the terminals  72  and  75 . 
       FIGS. 7A and 7B  show electronic circuits for utilizing pressure-sensitive conductive fabrics, electrical equivalents of variable resistors  70  and  74 . When there is no tightening,  FIG. 7A , the conductive fabrics  67  and  68  are electrically equivalent to an open switch. When the harness is tightened,  FIG. 7B , the conductive fabrics  67  and  68  are electrically equivalent to a variable resistor where the tighter the harness loop, the lower the electrical resistance. 
     For the tightening to be sufficient, a predetermined voltage, for example 0.1 V, must be measured between the terminals  72  and  75  of the sensor  38 , the electrical equivalent of variable resistors  70  and  74  connected in parallel to each other, and connected together in series with a fixed resistor  71  linked to the positive pole of the electrical supply of the first control unit  42 . The use of a 10-kilohm fixed resistor  71  allows the circulating current to be limited. 
     It is noted that, when the tightening is non-existent or insufficient, the terminal  73  is isolated from the electrical ground, as shown in  FIG. 7A , and no current circulates. This limits electrical consumption solely to periods when the device is being used. 
     In other embodiments in which the chest belt is closed by clipping metal fasteners together, the tightening of this chest belt can be checked by using stitched conductive threads placed over the entire length of the strap forming this belt. These conductive threads connect each of the conductive fabrics  67  and  68  to the first control unit  42 , with electrical continuity being provided by the metal fasteners of the belt. 
     With regard to the engagement sensor  40 , in its embodiment shown in  FIG. 8  a presence detector  77  checks that the snap hook  76  is engaged with a portion  78  of the ring  29 , by means of magnetic detection. More generally, a sensor detecting presence in a hook can be a sensor detecting the modulation of an electromagnetic field (electrical, magnetic, or light) by a portion  78  of the ring  29 . 
     In the case where each snap hook of the lanyard comprises a sensor checking its engagement on a metal part (harness ring or tether point), the electrical connections from at least one engagement sensor incorporated in a snap hook to the second control unit  41  can be realized by stitched conductive threads. 
     The first control unit  42  performs:
         the comparison of the tightening force value represented by the signal supplied by at least one measurement sensor with a predetermined minimum force value;   the comparison of the tightening force value represented by the signal supplied by at least one measurement sensor with a predetermined maximum force value;   the notification of a tightening fault if, for at least one measurement sensor, the measured force is below the predetermined minimum force value or greater than the predetermined maximum force value.       

     By means of a communicating terminal, the first control unit makes it possible to set at least one predetermined force value. For example, a user interface displayed on a display screen of the communicating terminal makes it possible to assign a numerical value to each of the predetermined minimum and maximum force values. Alternatively, this user interface makes it possible to assign a value for the users weight and/or the applicable regulation, and the communicating terminal determines the minimum and maximum force values to be applied. 
     For the lanyard  27  shown in  FIG. 2 , an engagement sensor is provided at each extremity of the lanyard  27 , on the harness  30  side and on the tether point side. 
     As the lanyard is attached to but separate from the harness, a second electronic circuit and a second control unit  41  are necessary. Like the first control unit  42 , light and/or sound indications can be seen or heard by the user and sent to a communicating terminal. 
     Some embodiments of the device that is the subject of the invention can be adapted to very different snap hook shapes. In some embodiments, such as that shown in  FIG. 9 , two photoelectric cells act as presence detector for the second control unit  41 . The first measures the light intensity in the vicinity (reference value), and the second is darkened when an object is placed in the optical field of the cell. This solution ensures reliable operation even in very low light conditions. The electrical resistance of each photoelectric cell varies with the intensity of incident light. For the tethering hook, when an object (fixed point or guardrail) is present in the detection area of the second photoelectric cell, the light intensity is reduced on the second photoelectric cell and the difference between the signal emitted by the second photoelectric cell and the signal emitted by the first photoelectric cell indicates that the lanyard is correctly positioned. 
       FIG. 9  shows an electronic circuit in the case where a photoresistor  80  is used to detect the presence of a portion  78  of the ring in the snap hook  76 . The electrical resistance, variable with the incident illumination, of the photoresistor  80  is measured by connecting it in series with a fixed electrical resistor  81 , for example of  10  kilo ohms, between the terminals  79  and  83  of the electrical supply, the measurement being made at terminals  82  and  83  of the photoresistor  80 . 
     Preferably, as shown in  FIG. 9 , the ambient light level measured with a complementary photoresistor  80 ′ in series with a fixed electrical resistor  81 ′, and the light level in front of an obstacle (in our case the anchor point) are compared. The photoresistors  80  and  80 ′ are identical but positioned in different locations so that the illumination of the photoresistor  80 ′ is not affected by the anchoring of the hook. The electrical resistors  81  and  81 ′ are the same. 
     If the two measurements made at the terminals  82  and  82 ′ are close, for example a difference of less than twenty-five percent, this indicates that the hook is not positioned on the anchor point. Conversely, if the two measurements are very different, this indicates that the hook is positioned in front of an obstacle (ladder rung, anchor point, guardrail). This comparison makes it possible to avoid false alerts linked to variations in the ambient light conditions. 
       FIG. 10  partially illustrates an embodiment of the harness that is the subject of the invention, comprising a dorsal ring  84 , an energy absorber  85 , a lanyard  27 , a first unit  42 , a tethering hook  88  for fastening on a tether point  89 , and a third unit  90 , similar to the second unit  41 . 
     It is noted that, ideally, when the harness is not correctly positioned on the user or is removed intentionally in a hazardous area, the person responsible for worksite safety must be informed of this, in addition to the user. 
     It is not always possible to ensure that the lanyard is connected to a reliable attachment point. The user might circumvent the proximity detector, for example by attaching a strap with the lanyard connector. To overcome this problem, in some embodiments there is an electronic tag at each of the predefined fixed tether points, and an electronic tag reader is incorporated in the second electronic control unit  41  of the lanyard  27 . The presence of an electronic tag guarantees that the connector of the lanyard is positioned on a fixed tether point. For the guardrails (taut cables), this solution would only be applicable if the guardrail transports an identification signal, for example by forming an antenna. In some embodiments, a magnetized part is placed at the disconnect point of the guardrail, the magnetization being detected by the engagement sensor to confirm the disconnection. 
     Therefore, in embodiments where one wants to prevent the user from being able to place a dummy object in the snap hook, an identifier can be positioned on the tether point or guardrail, for example a label or an electronic tag, and an identifier reader can be incorporated in the engagement sensor positioned on the inside of the snap hook of the restraint lanyard, with a controller verifying the identifier read in this way. In the case of an electronic tag, a communication protocol such as RFID (Radio Frequency Identification) can be utilized. 
     Each control unit of the harness and lanyard comprises, for example:
         a microcontroller board, which manages the sensors;   a remote communication board, for example using the Bluetooth (registered trademark) protocol, which transfers information to a communicating terminal;   an electrical power supply, for example using a cell or battery recharged through a connector, for powering the boards of the unit; and   a local alarm device (sound, light, or vibration).       

     As the harness that is the subject of the invention is used outdoors, the unit preferably has a water splash protection class of at least IP67 and impact resistance at least equal to IK8 class, compatible with on-site working. If used in an explosive atmosphere, the unit needs to be ATEX-certified. 
     The unit is preferably permanently fastened to the harness, as opposed to a removable fastening. On the harness, the measurement sensors make it possible to control the tightening force of the leg straps, shoulder straps and the closure of the chest belt. The incorporation of pressure sensors poses no specific problems with certain harnesses that have double straps or a single strap covered with a comfort material (e.g. foam), for example by placing the pressure sensor between two straps. 
     To check the closure of the chest strap, depending on its type, the following is provided, for example: for clip closures, the sensor described above; for quick-release closures, a contact similar to the contacts used in car seat belts; for snap hook closures, a magnetic or optical sensor. 
     In some variants not shown, the second control unit  41  and/or the third unit  90  of the restraint lanyard is connected to the first control unit  42  of the harness by a wireless connection. The restraint lanyard can be mechanically linked to the harness by a dorsal fastening point  84  of the harness (as shown in  FIG. 10 ), an abdominal fastening point of the harness, or a lateral fastening point of the harness. 
     To make sure that the user observes the various safety measures, a control system, provided for a crew manager, enables the crew manager to be informed of the state of the various sensors on the harness and on the restraint lanyard. 
     Preferably, the alarm signals sent to the user are sound, light, or vibration signals at the location of the monitoring units and/or at the communicating terminal. 
     Preferably, to avoid having alarms triggered when, for example, the user changes lanyard to carry out his task, a device allows the user to indicate a deliberate uncoupling of the lanyard. An electronic tag on the abdominal loop can be used for this purpose. When the user moves, he places the snap hook  39  on the abdominal loop. An electronic tag could be positioned there, which would be identified as an “authorized point”. 
     In some embodiments not shown, the communicating terminal performs additional useful functions related to the safety of the user such as, if supported by the data exchange protocol, connecting to other personal protection equipment (PPE), image capture, access control, monitoring the outside temperature, monitoring for the loss of wireless links, noise measurement, and/or LMRA (Last Minute Risk Analysis). 
     In some embodiments, instead of stitched conductive threads, a harness is used that comprises conductive textiles, for example comprising graphene or carbon nanotubes. The harness structure is therefore conductive. In some embodiments, the pressure or voltage sensors comprise nano-LED light barriers, magnetic sensors, or ultrasonic sensors. 
     Other types of sensor can be utilized to check the position and correct tightening of the harness or the fastening of the lanyard on the harness or tether point. For example, sensors for:
         measuring an angle;   measuring mechanical stress;   measuring a current;   measuring an electrical or magnetic field;   measuring a flow rate;   measuring displacement;   measuring distance;   measuring force;   measuring inertia;   measuring luminosity;   measuring levels;   measuring position;   measuring pressure;   measuring sound frequency or intensity;   measuring temperature;   measuring electrical voltage;   measuring physical tension.       

     As shown in  FIG. 11 , in some embodiments the method for protecting a user wearing a harness that is the subject of the invention comprises:
         a step  91  of setting at least a predetermined minimum force value and, optionally, a predetermined maximum force value;   a step  92  of capturing, for at least one loop, the measurement of the tightening force on said loop;   a step  93  of comparing the measured force represented by the signal coming from the measurement sensor with a predetermined minimum force value;   a step  94  of comparing the measured force represented by the signal coming from the measurement sensor with a predetermined maximum force value;
 
and, if the measured force is below the predetermined minimum force or the predetermined maximum force:
   a step  95  of transmitting to a user communicating terminal an item of information representative of a tightening fault, and of triggering a local alarm on said terminal; and   a step  96  of storing the timestamped information representative of the tightening fault.       

     The method also comprises:
         a step  97  of detecting, for the fastening means, the fasteners engagement with a lanyard;   a step  98  of detecting an engagement fault, as a function of the signal provided by the engagement sensor; and, if an engagement fault has been detected:   a step  99  of transmitting to a user communicating terminal an item of information representative of an engagement fault, and of triggering a local alarm on said terminal; and   a step  100  of storing the timestamped information representative of the fault.       

     Should at least one tightening fault, below the predetermined minimum value or greater than the predetermined maximum value, or an engagement fault be detected, the method also comprises:
         a step  101  of counting the number of faults detected and of comparing this number with a predetermined limit value, for example five, during a predetermined length of time, for example five minutes;   if the number of faults is greater than the limit value, a step  102  of transmitting to a supervisor communicating terminal an item of information representative of this limit value being exceeded;   a step  103  of triggering an alarm at the location of this supervisor communicating terminal; and   a step  104  of storing, with timestamp, the triggering of this alarm.