BE1023168B1 - SYSTEM OF PROTECTION OF PEOPLE ON SITE BY PRECISE LOCATION. - Google Patents

Abstract

Individual or collective protection system for people (1) located in a potentially dangerous zone, comprising: - a plurality of reference terminals (3) and a central terminal (4), distributed in said zone, said reference terminals (3 ) communicating bidirectionally with each other and with the central terminal (4), and capable of measuring the distance which separates them from each other with an accuracy at least equal to a predetermined value, the central terminal (4) being capable of determining a two-dimensional or XY coordinate system, i.e. to assign a position to three reference terminals (10, 20, 30) and then locate the other reference terminals (40, ...) in this reference frame XY by a trilateration method; - at least one mobile transceiver, called tag or beacon (6), carried by a person (1) and capable of communicating bidirectionally with the central terminal (4) and with other tags (6), as well as of measuring by trilating the distance separating it from each of the reference terminals (3), said tag (6) being provided with danger warning means which can be actuated by the central terminal (4); - means (5) for tracing a border (2) of the potentially dangerous zone from the position of the reference markers (3) once located in the aforementioned XY frame, said border (2) being intended for the definition of at least one zone in which the presence of a person (1) causes the central terminal (4) to actuate the danger warning means associated with the tag (6).

Description

SYSTEM OF PROTECTION OF PEOPLE ON SITE BY

PRECISE LOCATION

The present invention relates to a system of collective or individual protection of the human person in places where provisions aimed at the safety of persons, in particular the prevention of falls of workers, are required. . The use of the system can thus extend to the protection of any human being confronted with dangerous zones, for example the protection of pedestrians against collisions with civil engineering equipment, construction site or in relation to any other vehicle confronted by example to a danger of falling, of turning over in dangerous areas or around them.

STATE OF THE ART [0002] The state of the art is described below in a series of documents, without this state of the art being considered exhaustive.

[0003] GB200816469 describes an industrial process protection by selective access authorization according to the position and the identity of the carrier of a portable communicator (electronic tag). The position of the user can be determined by RTLS.

[0004] CA2709171 describes a worker protection on railway tracks based on the detection of the worker carrying a "tag", urF central system determining the position of the worker relative to the approaching train and warning him as soon as he has left him that little time to get away. The terminals that litter the course of the train are for example connected to each other using son.

[0005] US200810099 discloses a system for protecting people by determining their position vis-à-vis industrial processes. These processes can in no case start if a zone has not been evacuated for example. The problem is very similar to that of GB200816469.

[0006] CN102768352 and CN202770989U describe a mining protection system (underground) based on joint localization in UWB and ultrasound, necessitated by a large number of echoes.

[0007] EP2226646 describes a "relative" or "mobile" location system. The system includes wireless transceiver modules connected to a wireless network. Among these there is a central "anchor" of known position in the space considered and acting as a base station, the other modules having a position to be determined with respect to this base station. Nevertheless, no means are advanced to define a boundary delimiting a danger zone.

[0008] DE202008005467 describes a system for locating people in a tunnel from anchors in the form of wireless transmitters / receivers whose position is known.

[0009] CN101571406 discloses a pet location system.

[0010] IT2004BA0059 describes a system for locating people or animals which transmits the position step by step through a network of fixed transmitters / receivers and which are aware of their absolute position.

US2003122666 discloses a triangulation position measuring system by playing on the phase of the received signals. The invention describes a method of positioning requiring anchors whose posifibns and orientations are known.

WO200398528 discloses a method of measuring distance between two objects provided with RF tags.

[0013] US20030052776 discloses a method of measuring distance between two objects based on UWB.

[0014] BR9000368U discloses a bracelet positioning system with remote and automatic reading.

[0015] EP2282106 describes a system for locating workers in an area by laser scanning.

[0016] KR101258905 describes a worker protection system presenting only two RTLS tags (position of a crane and a worker's position) and an access point connected to a server.

KR20110017707 describes a location system in a tunnel from fixed terminals (similar to CA2709171).

CA2768054 discloses a complex location system using the power method received in a building. The system requires a calibration phase but checks itself whether there are enough anchors. The system needs to be told the building topology, access points, etc.

US2010017126 describes a location system, visibly GPS or SPS satellite, wherein a visibly circular area is defined with respect to a first localized object. Then a series of alerts are given if other objects approach this first object.

JP2009020847 describes a system for preventing accidents of the elderly or disabled using anchors placed inside a house. Each tag receives a signal strength from a tag, which makes it possible to determine if a tag is near an anchor and give an alert if necessary. Communication is via the electrical network (such as a lamp supply line for example).

[0021] WO2006085280 describes a GPS-based large-scale animal tracking system using relays.

[0022] US2004087314 describes a system for locating a tag with respect to a single anchor using distance and angle measurements. Many general ideas are cited in this document such as the use of a touch screen but few details are given on how to build the system or manage obstacles. The desired precision is not mentioned either.

OBJECTS OF THE INVENTION [0023] The present invention aims to specifically protect miners, drillers, machine operators, workers present as well as occasional visitors in open quarries, mines, work sites with mining or not, demolition sites with explosives or not and demining areas.

In particular, the invention aims to provide a solution that no longer requires the manual encoding of the location of the reference terminals and allows the simple and effective tracing of a boundary.

Finally, the invention aims to obtain a solution based on the collaboration of people.

Main Characteristic Elements of the Invention [0026] A first aspect of the present invention relates to a system for the personal or collective protection of persons in a potentially dangerous zone, comprising: a plurality of reference terminals and a central terminal , distributed in said zone, said reference terminals communicating bidirectionally with each other and with the central terminal, ej: capable of measuring the distance separating them from each other with a precision at least equal to a predetermined value, the central terminal being able to determine a two-dimensional fiducial or γY, that is to say to assign a position to three reference terminals and then to locate the other reference terminals in this XY coordinate system by a trilateration method; at least one mobile transceiver, called a tag or beacon, carried by a person and able to communicate bidirectionally with the central terminal and with other tags, and to measure by trilateration the distance separating it from each of the reference terminals said tag being provided with hazard warning means operable by the central terminal; means for tracing a boundary of the potentially dangerous zone from the position of the reference terminals once located in the aforementioned XY coordinate system, said boundary being intended for the definition of at least one zone in which the presence of a person causes the central terminal to activate the danger warning means associated with the tag.

According to preferred embodiments, the system of the invention comprises at least one or, where appropriate, an appropriate combination, of the following additional features: the central terminal is placed in a case equipped with a controller and input / output means; the input / output means comprise pushbuttons and a screen, preferably a touch screen; - the reference and central terminals are equipped with UWB radio transmitters and / or ultrasonic transducers; the warning means are light, acoustic and / or vibratory means; the predetermined value of precision on the determination of the distance separating the terminals between them is 50 cm, preferably 10 cm.

A second aspect of the invention relates to a method for implementing the above-mentioned system for the individual or collective protection of persons in a potentially dangerous zone, characterized by at least the following steps: the plurality of terminals is installed; reference arbitrarily in the potentially hazardous area; the central terminal interrogates the plurality of reference terminals and determines the distances separating them from each other as well as the distance separating them from the central terminal; the central terminal establishes a two-dimensional reference reference mark or XY which will be used for locating people; a closed boundary of the potentially dangerous zone, said red zone, is determined and filtered, said closed boundary being defined as being a polygon, that is to say a set of points or vertices connected by segments of the right or sides; ; a boundary of an area within the red zone is defined, defining a so-called orange zone, the zone lying inside the boundary delimiting the orange zone being defined as the safety zone for the people or green zone, the previous steps being configuration steps; - In operation, it provides a tag every person brought to be in the potentially dangerous area; the central terminal periodically interrogates all the tags, determines their position in the XY coordinate system and assigns each of these positions a location either in the green zone, in the orange zone or in the red zone; if one of the tags is in the orange or red zone, the central terminal activates the warning means associated with said tag and optionally activates one of the warning means associated with the other tags. According to preferred embodiments, the method of the invention comprises at least one or, where appropriate, an appropriate combination, of the following additional characteristics: the red zone boundary is determined: either by using a locating the reference terminals in the XY mark displayed on a touch screen associated with the central terminal and by drawing said boundary on the touch screen in the form of the aforementioned polygon; or by using a device called a plotter which communicates with the central terminal and the reference terminals, the central terminal periodically interrogating the plotter when it is moved in the area and asking it for the respective distances separating it from the reference terminals, which allows at the central terminal, to determine the successive positions of the tracer in the XY coordinate system and to create the boundary by joining these positions by line segments to create the aforementioned polygon; or by geometric location starting from the positions of a plurality of reference terminals in the XY coordinate system and applying a homothety to define a boundary that includes the polygon made by the reference terminals; - The filtering of the red zone boundary is achieved by replacing the constituent vertices of the above-mentioned polygon by a reduced number of vertices connected by line segments or sides, so that the filtered boundary substantially corresponds to the departure boundary; the border of the orange zone is determined from the red zone boundary by creating an inner polygon by homothety, the distance corresponding to the withdrawal being between 50 cm and 1 m; - the XY mark is established as follows by the central terminal: a first (reference) terminal is arbitrarily assigned to the coordinate (0, 0); a second terminal at a distance d is assigned to the coordinate (d, 0); a third terminal is located from the two aforementioned terminals using the intersection of two circles from the respective distances of the third terminal with respect to the two aforementioned terminals, one of the two possible intersections being arbitrarily chosen as the position of the third terminal; the following terminals are located from the first three bounds using a trilateration algorithm. a refinement step is used to render the location algorithm insensitive to the initial choice of the first three terminals.

BRIEF DESCRIPTION OF THE FIGURES [0030] FIG. 1 schematically represents a general and synthetic view of the personal protection system according to the present invention.

[0031] Figure 2 schematically shows the creation of an XY landmark.

[0032] Figure 3 schematically shows the respective red, orange and green zones defined around a moving vehicle.

FIG. 4 represents an example of boundary filtering.

DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS [0034] The system according to the present invention makes it possible to warn the minor or any other person located near a danger zone. This warning is made through a transceiver, or tag or tag, worn by the person directly on the body or on personal protective equipment (PPE). The transceiver or the tag indicates the danger by luminous, acoustic and vibratory signals, whether or not depending on the danger.

The operation requires that each transceiver }· locate itself in relation to the danger zone. To do this, several reference terminals are placed in the field. After laying the terminals, a configuration step preferably consists of moving a special transceiver called a tracer along the boundary between the danger zone and the safety zone. This step allows the system to record a set of positions that ultimately define the warning limit. The recording is done within a central terminal placed preferably in a suitcase.

The location of the transceivers with respect to the terminals is performed by a trilateration or triangulation system.

A feature of the invention is that the definition of the area is during the tracing while the terminals were initially arbitrarily laid and that the position of the reference terminals is unknown during the installation of the device and will remain so throughout the operation of the device. The resolution of this apparent contradiction is an element of the invention.

A second feature is the protection of the system against measurement errors by the redundancy of measurements and the redundancy of communication channels between the terminals, the (or) receivers) and the bag.

Figure 1 schematically shows the various components of the system of the invention: a person 1 holder of a tag 6 (here in the green zone), the reference terminals 3, the central terminal (and the bag) ) 4, the tracer 5 and the three safety zones 7, 8, 9.

Generic problem to be solved [0040] The problem to be solved is to warn one or more people that they are possibly in danger because of their position. This position must be obtained quickly, accurately (+/- 10 cm for example) indoors and outdoors. This last point excludes any solution based on a system of geolocation (GPS).

The danger is defined according to the position occupied by the person (s). More precisely, it is desired to map, according to the invention, a given space into three zones: green zone: zone in which there is no danger; - orange zone: zone in which there is no danger but which is close to a danger zone; - red zone: zone in which there is effective danger.

The problem to be solved is then reduced along two axes: - provide a solution to define these three areas and - provide a solution to determine in which area a person is with a desired location accuracy of +/- 10 cm by example.

Special features of the problem The particularities or requirements of the problem to be solved are the following: speed of implementation, need for moving zones (around a truck for example), determination of the time and of the position of the system, - presence of obstacles, - collaborative protection, - principle of the traffic light with a universal three-zone code (green, red, orange) and - rapid determination of a boundary.

Proposed solution [0044] The proposed solution is thus based on a set of reference terminals which are distributed more or less uniformly in the area in which one wants to achieve the positioning of people.

These reference terminals communicate with each other and also communicate to a central bounded line. It is this central pillar that orchestrates the entire system. In a preferred implementation, it is envisaged to place this central terminal in a suitcase to provide a screen, touch or not, and pushbuttons.

The reference terminals are also capable of measuring the distance separating them by means known to those skilled in the art. One solution, for example, is to use UWB radio transmitters or ultrasonic transducers with a TOF (time offlight) method.

It will be noted that the UWB technology, like other technologies, can evaluate a degree of reliability over the distance returned as well as the presence of potential obstacles. This information is advantageously used to reject any calculation distances considered unreliable.

Creation of an "XY" Mark [0048] Once the reference terminals have been installed, the user asks the system to check the placement of the terminals. To do this, the central terminal interrogates the set of reference terminals and asks them for the distance that separates them from each other.

[0049] Any location requires a reference mark. According to the prior art, it is still required that this marker be defined by assigning known positions to the reference terminals. The proposed invention, however, does not require this heavy constraint for a system that needs to be installed quickly.

From the distance information collected about the reference terminals, the central terminal determines an XY mark that will be used for further localization. This determination works in several steps (see also Figure 2): 1) A terminal 10 is arbitrarily assigned to the coordinate (0, 0). 2) A second terminal 20 which is at a distance d is assigned to the coordinate (d, 0). 3) A third terminal 30 is located from the other two using the intersection of two circles from the distance information (= radius of the circles). This creates ambiguity because there are two possible intersections. One of the two positions is then arbitrarily chosen. 4) At this stage, since three reference terminals are located, all the other terminals (eg terminal 40 on the figure) can be located by trilateration algorithms known to those skilled in the art. 5) A refinement step is possible once all the coordinates of the determined terminals. This step aims to make the localization algorithm insensitive to the initial choice of terminals in steps 1), 2) and 3).

Finally, it will be noted that the choice of the terminals in steps 1), 2) and 3) can be based on the reliability of the distance measurements. The terminals corresponding to the most reliable distance measurements will thus preferably be chosen. Determination of a boundary of the red zone [0052] It is envisaged, according to the invention, to determine the red zone boundary in at least three different ways from the position of the reference terminals located in an XY coordinate system. .

Location on a touch screen [0053] The reference terminals are located on a touch screen in an XY coordinate system. It is then possible to draw on the touch screen a limit determining the red zone. The boundary is then defined as a set of closely spaced points joined by straight line segments.

Tracer Location [0054] As already mentioned above, an apparatus called a tracer capable of communicating with the central terminal and the reference terminals is moved along the boundary by a person, for example by walking. The central terminal interrogates the plotter periodically (typically 10x per second) and asks for the distances-which separates it from the reference terminals. From this information, the central terminal determines the successive positions of the tracer and thus creates a boundary by joining these positions approximated by line segments. As a non-limiting illustration, the tracer could be embodied in the form of a wheel provided with a handle. The wheel could be advantageously used to send the aforementioned periodic signal which would correspond to a given displacement thereof.

Geometric localization [0055] In the case of reference terminals placed at the four "corners" of a vehicle such as a truck for example, the danger zone is defined by connecting the four reference terminals by segments of the right and by applying a homothety to define a larger rectangle that delimits the danger zone (red), as shown in Figure 3.

It is also envisaged to consider the presence of danger in the direction of movement of the vehicle to minimize the alerts that prevent vehicles from moving because of the signaling of false dangers.

Note also that it is also envisaged to locate the mobile reference terminals of the truck relative to the fixed reference terminals in the same way that we locate the tags. With this, it is possible to have a complete map of the location of vehicles and pedestrians.

Boundary Filtering [0058] As explained above, the boundary is defined by a set of points connected by straight line segments. In the case of the plotter, if the person fitted with the plotter moves at a speed of 1 m / s and determines a 1 km long boundary, this represents 10,000 points and segments (if acquisition of 10 points per second). It is therefore advantageous to modify this boundary and replace it with a reduced number of points and segments by "filtering". This step is performed once and reduces the computational power required to determine the position of the tags in relation to the borders. FIG. 4 ~ represents an example of boundary filtering (raw data obtained from tracer 50 and border after filtering 51). Determining a border of the orange zone The orange zone is defined by a distance parameter with respect to the red zone. For example, we can decide that a tag enters the orange zone if it is less than 80 cm from the red zone. Given a boundary defined by a set of segments, it is easy for a person skilled in the art to find the geometric algorithms necessary to derive if a tag is or is not less than 80 cm from the border. Securing in operation [0060] In operation, anyone who arrives in a protected area must wear a tag. This tag is a mobile transceiver, capable of communicating with the central terminal and capable of measuring the distances that separate it from the reference terminals.

Once the border corresponding to the red and orange areas is defined relative to the reference terminals, the central terminal is able to periodically interrogate all tags for which it provides protection, to determine their position in the XY mark and evaluate this position with respect to the boundaries of the previously defined zones.

The tags are advantageously provided with visual, auditory and / or vibratory signaling means. When a tag enters an orange or red zone, it is notified by the central terminal.

It is intended, according to a particular embodiment of the invention, to warn other tags so that several people forming a team can monitor and protect themselves from each other.

Thus, if a tag enters a red zone, it can for example begin to vibrate, emit a shrill sound and indicate a red light signaling. Tags worn by other people will only emit a sound for example. Thus, the bearers of such a tag know that someone else in the group of people is in danger.

The originality of the present invention resides first in the solution provided to not have to manually encode the location of the reference terminals. A second originality is la., The way the boundary is defined using a tracer and filtered. The idea of making the system based on the collaboration of people is also innovative.

Glossary - UWB (ultra-wideband signal): Broadband signal (over 100 MHz standardized by IEEE 802.15.4a - 2007). - RTLS: real-time location System. - anchor (anchor point, beacon, reference terminal): a fixed or mobile object used as a reference to locate another object.

Benchmarks 1 person to protect 2 danger zone boundary (red zone) 3 reference terminal 4 center bollard (with suitcase) 5 border plotter 6 tag carried by the person 7 green zone 8 orange zone 9 red zone

Terminal No. 1 in the XY mark 20 terminal No. 2 in the XY mark 30 terminal No. 3 in the XY mark 40 terminal No. 4 in the XY mark 50 raw boundary 51 filtered boundary

Claims (12)

1. Personal or collective protection system of persons (1) in a potentially dangerous zone, comprising: - a plurality of reference terminals (3) and a central terminal (4), distributed in said zone, said reference terminals (3) communicating bidirectionally with each other and with the central terminal (4), and capable of measuring the distance separating them from each other with an accuracy at least equal to a predetermined value, the central terminal (4) being able to to determine a two-dimensional reference or XY, that is to say to assign a position to three reference terminals (10, 20, 30) and then to locate the other reference terminals (40, ...) in this XY mark by a trilateration method; at least one mobile transceiver, called a tag or beacon (6), carried by a person (1) and capable of communicating bidirectionally with the central terminal (4) and with other tags (6), as well as measuring by trilateration the distance separating it from each of the reference terminals (3), said tag (6) being provided with hazard warning means operable by the central terminal (4); means for tracing (5) a boundary (2) of the potentially dangerous zone from the position of the reference terminals (3) once located in the aforementioned XY mark, said boundary (2) being intended for the defining at least one zone in which the presence of a person (1) causes the central terminal (4) to actuate the danger warning means associated with the tag (6). 2. Protection system according to claim 1, characterized in that the central terminal (4) is placed in a bag provided with a controller and input / output means. 3. Protection system according to claim 2, characterized in that the input / output means comprise pushbuttons and a screen, preferably a touch screen. Protection system according to Claim 1, characterized in that the reference terminals (3) and the central terminal (4) are equipped with UWB radio transmitters and / or ultrasonic transducers. 5. Protection system according to claim 1, characterized in that the warning means are light, acoustic and / or vibratory means. 6. System according to claim 1, characterized in that the predetermined value of precision on the determination of the distance, separating the terminals (3, 4) between them, is 50 cm, preferably 10 cm. 7. A method of implementing the personal or collective protection system of persons (1) in a potentially hazardous area, according to any one of the preceding claims, characterized by at least the following steps: - installing the plurality of terminals of reference (3) arbitrarily in the potentially hazardous area; the central terminal (4) interrogates the plurality of reference terminals (3) and determines the distances separating them from each other as well as the distance separating them from the central terminal (4); - The central terminal establishes a two-dimensional reference reference or XY which will be used for locating people (1); a closed boundary (2) of a potentially dangerous zone, called a red zone (9), is determined and filtered, said closed boundary (2) being defined as being a polygon, that is to say a set of points or vertices connected by line segments or sides - a boundary of an area within the red zone (9) defining a so-called orange zone (8) is determined, the zone lying inside the boundary defining the orange zone being defined as the security zone for the persons or green zone (7), the preceding steps being configuration steps; - In operation, is provided with a tag (6) each person (1) to be in the potentially dangerous area; - The central terminal (4) periodically interrogates all the tags (6), determines their position in the XY coordinate system and assigns each of these positions a location either in the green zone (7) or in the orange zone (8). ), in the red zone (9); if one of the tags (6) is in the orange (8) or red (9) zone, the central terminal (4) activates the warning means associated with said tag (6) and optionally activates one of the warning means associated with other tags (6). 8. Method according to claim 6, characterized in that the boundary (2, 50) of the red zone (9) is determined: - either by using a location of the reference terminals (3) in the XY mark displayed on a screen touch associated with the central terminal (4) and by drawing said boundary (2, 50) on the touch screen in the form of the aforementioned polygon; or by using a device called tracer (5) which communicates with the central terminal (4) and the reference terminals (3), the central terminal (4) periodically interrogating the tracer (5) when it is moved in the zone and requesting the respective distances separating it from the reference terminals (3), which allows the central terminal (4) to determine the successive positions of the tracer in the XY coordinate system and to create the boundary (2, 50) by joining these positions by line segments to create the aforementioned polygon; either by geometric localization starting from the positions of a plurality of reference terminals (3) in the XY coordinate system and by applying a homothety to define a boundary (2, 50) which encompasses the polygon made by the reference terminals. 9. Method according to claim 6, characterized in that the filtering of the boundary (2, 50) of the red zone (9) is achieved by replacing the constituent vertices of the aforementioned polygon by a reduced number of vertices connected by segments of right or sides, so that the filtered boundary (51) substantially corresponds to the departure boundary (2, 50). Method according to claim 6, characterized in that the boundary of the orange zone (8) is determined from the boundary (2) of the red zone (9) by creating an inner polygon by homothety, the distance corresponding to the shrinkage being between 50 cm and 1 m. 11. The method of claim 6, characterized in that the XY mark is established in the following manner by the central terminal (4): a first terminal (10) is assigned arbitrarily to the coordinate (0, 0); a second terminal (20) at a distance d is assigned to the coordinate (d, 0); a third terminal (30) is located from the two aforementioned terminals (10, 20) using the intersection of two circles from the respective distances of the third terminal (30) with respect to the two aforementioned terminals (10, 20); ), one of the two possible intersections being arbitrarily chosen as the position of the third terminal (30); the following terminals (40, ...) are located from the first three terminals (10, 20, 30) using a trilateration algorithm. 12. The method of claim 10, characterized in that a refinement step is used to make insensitive to the initial location algorithm of the first three terminals (10, 20, 30).