Method for determining an anchor position

Abstract

The invention relates to a method for determining the position of an anchor (22), characterised in that the method comprises the following steps: -a) determining the initial position of an anchor (22) connected to a boat (20) and to a buoy (21); the buoy (21) is connected to the anchor (22) by a cable (23) comprising an automatic winder configured to maintain a constant tension on the cable (23) between the buoy (21) and the anchor (22); - b) determining the movement of the anchor (22) via sensors of the buoy (21); - c) determining, over a regular time interval, the change in position of the anchor (22) using the sensors from the preceding step; - d) receiving, on the boat (20), data originating from the sensors of the buoy via a data-receiving antenna belonging to a receiver box (25), wherein the buoy (21) comprises a radio transmitter configured to transmit a status signal of the anchor to the boat (20); - e) sending a message with the position of the anchor (22) to a mobile terminal.

Description

Description Title: Method for determining anchor position. [Technical field. [1] The present invention relates to a method for determining anchor position. It applies, in particular, in the field of maritime technology. Prior art [2] To immobilize a boat at the end of a navigation, an anchor is dropped into the water. An anchor is a fixing device used to hold an object firmly in place. [3] Nowadays, an anchor is an essential element to prevent a boat from drifting. [4] When the anchor fails to maintain a stable position, the boat may drift, moving away from its intended anchorage point and potentially coming dangerously close to obstacles such as other boats, rocky shores or sandbars. [5] Certain prior art documents also propose devices for determining the position of an anchor. For example, publication document EP19020016 is known, which describes a method and system for determining the displacement of an anchoring element. [6] This system has the following disadvantages: [7] Underwater measurement of displacement speed by Doppler effect or image processing seems uncertain, especially in an area where there is a current. [8] The transmission of underwater signals by acoustic means greatly disturbs underwater fauna and prevents it from developing naturally. [9] Underwater signal transmission is imprecise and subject to loss.

[0010] The user of the said process is obliged to pierce its hull to install a receiver which comes into contact with the water.

[0011] The system is not energy self-sufficient and must be recharged regularly.

[0012] Patent document WO2014 / 027210 also discloses a method for determining anchor position. This method requires a mobile phone to receive data on the buoy's position. The main disadvantage of this method is that in the event of a network outage (which is common in the maritime sector), the anchor's position cannot be tracked. Presentation of the invention.

[0013] The present invention aims to overcome these drawbacks with a completely innovative approach.

[0014] More specifically, the invention aims to provide a method for determining the position of an anchor and providing an alert in the event of it slipping on the seabed.

[0015] In particular, one objective of the invention is to provide such a technique making it possible to do away with any other complex adjustment system.

[0016] An objective of the invention is to provide such a method, which can be easily adapted to existing systems.

[0017] These objectives, as well as others which will appear subsequently, are achieved using a method for determining anchor position, remarkable in that the method comprises the following steps: -a) determining the initial position of an anchor connected to a boat and to a buoy; said buoy is connected to the anchor by a cable comprising an automatic reel configured to tension the cable between the buoy and the anchor, said initial position of the anchor being determined by a satellite position sensor of said buoy; -b) determining the displacement of said anchor by the satellite position sensor of said buoy; -c) determining during a regular time interval the change in position of the anchor using the sensor from the previous step; -d) receive, on a receiving box positioned on said boat, data from the satellite position sensor of the buoy and / or an anchor status signal, said data or said signal being received via a data receiving antenna belonging to a receiving box, said data and / or said signal being emitted by a radio transmitter of said buoy; -e) send a message of the anchor position to a mobile terminal.

[0018] With these arrangements, the buoy is used to link the movement of the anchor to the user on the boat. The sensor data is processed in the receiver box or in the buoy and an alarm signal is generated in the event of anchor slippage detected in step c).

[0019] The anchor status signal is transmitted to the boat's receiver box in a more reliable, robust, and secure manner. The boat's receiver box receives the anchor's position and / or status signal directly, without going through a mobile communications network. This local management reduces the risk of data and / or signal loss in often adverse marine environments.

[0020] Other advantageous features of the invention are listed below. Each of these features can be considered alone or in combination with the remarkable features defined above. Each of these features contributes, where appropriate, to the resolution of specific technical problems defined further in the description and in which the other features defined above do not necessarily contribute. The following characteristics may thus be the subject, where appropriate, of one or more divisional patent applications:

[0021] According to one embodiment, the satellite position sensor of the buoy is a GNSS position sensor.

[0022] According to one embodiment, during step b), the movement of the anchor is further determined by an accelerometer.

[0023] According to one embodiment, during step b), the movement of the anchor is determined by sensors of the buoy.

[0024] According to one embodiment, the sensors of the buoy are of the following family: an accelerometer; a shock sensor configured to detect a shock between another boat and the buoy; a motion sensor, for example infrared, configured to detect whether another boat is close to the buoy; an incremental encoder configured to count the number of turns of the cable winding unwound; a sonar module configured to detect a variation in water depth and to deduce a possible movement of the anchor; a force sensor.

[0025] According to one embodiment, the automatic reel is configured to have a constant cable tension between the buoy and the anchor.

[0026] According to one embodiment, step b) and step c) are implemented in the receiving box.

[0027] According to another embodiment, step b) and step c) are implemented in the buoy.

[0028] According to one embodiment, the method comprises a step of configuring the buoy or the receiving box to determine different states of the anchor: - a "stabilizing" state during which the anchor does not have a stable position for a determined period; - a "stable" state during which the anchor has a stable position beyond a determined period; - a "skidding" state, in which the anchor, initially in a "stable" state, leaves its stable position.

[0029] According to one embodiment, during step e), the message sent to the mobile terminal is an alarm signal generated in the event of a slippage of the anchor observed during step c).

[0030] According to one embodiment, during step d), the data from the satellite position sensor of the buoy are transmitted at regular time intervals, said interval being adjustable.

[0031] According to one embodiment, the GNSS position sensor of the buoy is configured to provide an HDOP value and to calculate its position after a filtration step implemented to keep only the position data transmitted by satellites whose HDOP value is less than or equal to a threshold value.

[0032] According to one embodiment, the threshold value of the HDOP is adjustable.

[0033] According to one embodiment, the GNSS position sensor of the buoy is configured to provide the number of satellites used for calculating its position and to calculate its position by combining the data transmitted by at least ten satellites.

[0034] According to one embodiment, the method comprises a step of defining, via a user interface of the receiving box, a perimeter beyond which the buoy must not leave, an alarm signal being generated as soon as said buoy leaves said perimeter.

[0035] According to one embodiment, the perimeter is a circle whose center corresponds to the initial position of the buoy and whose radius has an adjustable value.

[0036] According to one embodiment, the method comprises a step of calculating the distance between the buoy and the boat, said distance being calculated: - from data coming from the satellite position sensor of the buoy and data coming from a satellite position sensor of the receiving box, or by calculating a round trip time of a radiofrequency signal emitted between the buoy and the receiving box.

[0037] According to one embodiment, the method comprises a step of installing the satellite position sensor and the radio transmitter of the buoy (21) in a removable waterproof housing, and a step of detachably fixing said housing on the hull of said buoy.

[0038] According to one embodiment, the data is processed in the buoy. In other words, the aforementioned steps a), b) and c) are implemented in the buoy. The receiving box on the boat only receives a signal in the event of a slip, and at regular time intervals, for example every five seconds or every five minutes, to ensure that the buoy is still in operation.

[0039] The buoy sends its position at regular time intervals, for example every five seconds, every five minutes, every hour, etc.

[0040] According to another embodiment, the data are processed in the receiving box. In other words, the aforementioned steps a), b) and c) are implemented works in the receiving box. The buoy's position data are transmitted by the buoy to the receiving box at regular time intervals, for example every five seconds or every five minutes. The determination of the initial position of the anchor, its movement and / or its change of position are thus processed and analyzed in the receiving box.

[0041] In one case, the message to the terminal is sent only in case of a skid.

[0042] The system is very simple to set up, there is no need to install anything by making a hole in the hull of the boat.

[0043] By counting the length of the cable between the anchor and the buoy, we can know very precisely the water height at the anchor location, a useful parameter to ensure that the anchor holds well.

[0044] In addition to providing a link between the sensors and the user, the buoy allows the exact position of the anchor to be located, and prevents other users from placing their anchor in the same location.

[0045] The sensors are, for example: an accelerometer; a shock sensor, which can detect a shock between another boat and the buoy; a motion sensor, for example by infrared, which can detect if another boat is close to the buoy, and therefore potentially in the process of placing its anchor on that of the user; an incremental encoder, which can count the number of turns of the cable winding unwound, and therefore deduce the water depth at the anchor; a sonar module, which can detect a variation in water depth and deduce a possible movement of the anchor; a satellite position sensor; a force sensor.

[0046] A strain gauge can be used to measure the tension in the cable connecting the buoy to the anchor. If this tension drops to zero, the buoy is no longer connected to the anchor. Either the cable has broken and the buoy is drifting, or it has been severed and the buoy has been stolen.

[0047] Using an accelerometer to measure the acceleration of the buoy refines the measurement of its displacement since this constitutes, with the sensor, satellite position an inertial unit. This is more reliable and accurate than underwater measurement by Doppler effect and image processing.

[0048] By focusing on the buoy's position, the user can define a perimeter beyond which it must not go out, otherwise the anchor will be slipping on the seabed.

[0049] The invention is advantageously implemented according to the embodiments and variants set out below, which are to be considered individually or in any technically effective combination.

[0050] In one embodiment, during step a) of determining the initial position or step b of determining displacement), said buoy comprises a rigid plastic shell. Thanks to these arrangements, the rigid shell makes it possible to have impermeability of the buoy and resistance to shocks.

[0051] In one embodiment, during step a) of determining the initial position or step b of determining movement), the buoy further comprises at least one of the following elements: a visual indicator, a luminous ribbon, a handle. Thanks to these arrangements, the buoy can be located more easily depending on the time of day and the weather conditions.

[0052] In one embodiment, during step a) of determining the initial position or step b of determining displacement), said buoy comprises a photovoltaic panel configured to power the elements in the buoy. Thanks to these arrangements, the photovoltaic panel makes the buoy entirely energy-autonomous.

[0053] In one embodiment, during step a) of determining the initial position or step b of determining the movement), said buoy comprises a battery and an induction charger to power the elements in the buoy. In this variant, the buoy equipped with an induction charging system allows the user to be able to recharge his buoy in the event of no sunlight. This also ensures that the system is overall watertight.

[0054] In one embodiment, during step d) of receiving data from the sensors, the buoy or the receiving box is connected to a mobile terminal. Thanks to these provisions, the boat user has the possibility of knowing the status of his anchor (stable or moving).

[0055] The mobile terminal is, for example: a digital tablet; a mobile phone, particularly a “smartphone” type; a connected watch; connected glasses; a remote control; a headset; a computer; a virtual reality headset; a connected television; a games console; or an internet box.

[0056] In one embodiment, during step d) of receiving data from the sensors, the receiving box comprises a user interface configured to consult the data from the sensors. For example, the data is configured to give the state of the anchor and the skid detection parameters. Thanks to these arrangements, the visualization of the data is easier for the user to consult.

[0057] In one embodiment, during step d) of receiving data from the sensors, the user interface, the receiving box (25) or the buoy (21) includes an alert in the event of the anchor slipping. Thus, the crew is alerted in the event of slipping on the seabed.

[0058] According to one embodiment, a skid is considered from a moment when the measured position is shifted from the initial position by a distance greater than or equal to a determined threshold value, for example shifted by a distance of at least 2 meters from the initial position. Brief description of the figures.

[0059] Other advantages, aims and characteristics of the present invention emerge from the description which is given, for explanatory and in no way limiting purposes, with reference to the appended drawings, in which:

[0060] [Fig.1] shows a diagram representing a method of determining anchor position.

[0061] [Fig.2] shows an example of a buoy.

[0062] [Fig.3] illustrates different electronic resources integrated into the buoy.

[0063] [Fig.4] illustrates an embodiment of the buoy, in which its electronic resources are installed in a removable housing.

[0064] [Fig.5] illustrates various electronic resources integrated into the boat's receiver box.

[0065] [Fig.6] illustrates an example of a perimeter beyond which the buoy must not go out. Description of the embodiments.

[0066] To possibly complete their current definition, the following clarifications are made to certain terms used in the claims and the description: - For the sake of clarity, it is to be understood within the meaning of the invention that "the buoy or the receiving box does something" means "the software executed by a processing unit of the buoy or the receiving box does something". - “Electronic resource” may be understood in a non-limiting manner as: component, sensor, user interface, hardware, software, file, connection to a network, amount of memory, hard disk space, bandwidth, processor speed, number of CPUs, etc. - “Processing unit” can be understood in a non-limiting way as: processor, microprocessors, CPU (for Central Processing Unit), etc. - "Software" can be understood as: computer application, computer program, computer microprogram, executable lines of code, software, etc. Software refers in particular to a set of computer programs, scripts and data which provide instructions to a computer or a computer system. - "Data network" can be understood in a non-limiting way as: internet network, cellular network, satellite network, etc. It is a set of computer equipment connected together to exchange, securely or not, information and / or data according to a communication protocol (ISDN, Ethernet, ATM, IP, CLNP, TCP, HTTP, etc.). - As used herein, unless otherwise indicated, the possible use of the ordinal adjectives "first", "second", etc., to describe an object simply indicates that different occurrences of similar objects are being referred to and does not imply that the objects so described must be in any given sequence, whether in time, space, order, or otherwise. - As used herein, unless otherwise indicated, the possible use of adjectives "right / left", "front / back", "top / bottom", "bottom / top", etc., are used to simply describe the position of an object in the configuration of the attached figures, but do not necessarily imply that in practice, similar objects are in the same position. - “X and / or Y” means: X alone or Y alone or X+Y. - Generally speaking, it will be appreciated that on the various attached drawings, the objects can be arbitrarily drawn to facilitate their reading.

[0067] [Fig.1] shows a diagram representing a method of determining the position of anchor 22.

[0068] This diagram shows that this process is carried out in a marine environment. In one example, the marine environment is the sea, but could be a lake or a maritime canal.

[0069] This diagram shows the following components: a buoy 21, an anchor 22 and a boat 20. The buoy 21 is connected to the anchor 22 by a cable 23. The anchor 22 is connected to the boat 20 by a chain 24. The cable 23 is tensioned by an automatic reel. According to one example, the cable 23 is made of dyneema, a registered trademark.

[0070] Dyneema is a trademark for an ultra-high molecular weight polyethylene fiber. This fiber is extremely strong and is used in a variety of applications for its light weight, exceptional tensile strength, and abrasion resistance.

[0071] In order to obtain a static or quasi-static positioning of the buoy 21 with the anchor 22, the buoy 21 advantageously comprises a spring-mounted dyneema winding. This dyneema winding is located inside the buoy 21. This makes it possible to obtain statics between the buoy 21, the cable 23, and the anchor 22. Description of buoy 21.

[0072] [Fig.2] shows an example of a buoy 21. The buoy 21 comprises a rounded area and a flat area. The rounded area of ​​the buoy 21 advantageously comprises a rigid shell 28 made of plastic. This rigid shell 28 provides impermeability, resistance to ultraviolet rays and protection in the event of contact with the surrounding environment. According to one example, the rounded area has a diameter between 20 cm and 30 cm. According to a variant, the diameter of the rounded area is 25 cm. The buoy 21 has a height between 20 cm and 30 cm. According to a variant, the height of the buoy 21 is 25 cm. The buoy 21 is connected and comprises sensors.

[0073] The flat area of ​​the buoy 21 advantageously comprises a photovoltaic panel 27. This photovoltaic panel 27 makes it possible to obtain recharging and energy autonomy. According to another variant, the energy recharging is done by induction with a standard charger. The energy autonomy of the system inside the buoy 21 is unlimited in the event of sunshine, and limited to three days in the event of a total absence of solar recharging.

[0074] According to one embodiment, the buoy 21 comprises a handle 26. This allows for a better grip of the buoy 21 manually.

[0075] According to one embodiment, in order to locate the buoy 21 according to the time of day, the buoy 21 advantageously comprises a visual indicator, such as a pennant and a light strip. According to one exemplary embodiment, the light strip is an LED.

[0076] According to one embodiment, the buoy 21 includes the following technical characteristics: geolocation, a radio antenna, and possibly software.

[0077] In Figure 3, the buoy 21 integrates a satellite position sensor 210 and a data transmitter 211. If necessary, the buoy 21 can also integrate one or more other sensors 212, one or more memories 213 in which software is recorded, a processing unit 214 and / or a communication interface 215.

[0078] The satellite position sensor 210 and preferably a GNSS geolocation module (for the English acronym for “Global Navigation Satellite System" or "Global Navigation Satellite System" in French), registered trademark, as explained further in the description. The position of the position sensor 210 corresponds to that of the buoy 21 and the anchor 22.

[0079] Geolocation allows you to know the actual position of anchor 22 in real time. The use of GNSS allows you to collect data on the frequency of coves, and to direct users to the least densely populated coves, which also reduces the risk of anchor 22 slipping. A GNSS is a satellite navigation system that can determine the precise position of a GNSS receiver anywhere on Earth. The GNSS system uses a network of satellites orbiting the planet to transmit signals that allow GNSS receivers to calculate their position and speed, using the principle of triangulation. The GNSS system brings together several navigation systems such as GPS®, GLONASS®, GALILEO®, BEIDOU®, etc. GNSS has global coverage.

[0080] According to one embodiment, the accuracy of the GNSS is between 1 meter and 3 meters. According to a variant, the accuracy is 2 meters.

[0081] The transmitter 211 is adapted to exchange data, via a short-range wireless link, with the receiving box 25 installed on the boat 20 and described further in the description. According to an exemplary embodiment, the buoy 21 comprises a radio wave connection to a receiving box 25 of the boat 20. The transmitter 211 is preferably in the form of a radio antenna. The short-range wireless link has, for example, a range less than or equal to 125 meters. The data exchanged includes the position data of the satellite position sensor 210 and possibly the data of the other sensors 212 and / or the data relating to the steps a) to d) claimed. These data are preferably included in radio frequency signals. The short-range wireless link preferably uses a communication protocol from the following family: Simple RF, Proprietary Wireless Communication, Bluetooth®, Zigbee®, LoRa®.

[0082] According to one embodiment, the radio antenna 211 transmits and receives on a frequency between 650 MHz and 1000 MHz or between 400 MHz and 1000 MHz. The term Mhz designates “mega hertz”, it is a unit of measurement of the frequency. According to one variant, the frequency is 868 MHz. According to another variant, the frequency is 433 MHz. The radio antenna allows a radio wave range of between 75 meters and 125 meters. According to one variant, the range is 100 meters.

[0083] The sensors 212 are, for example: an accelerometer; a shock sensor, which makes it possible to detect a shock between another boat and the buoy; a motion sensor, for example by infrared, which makes it possible to detect whether another boat is close to the buoy, and therefore potentially in the process of placing its anchor on that of the user; an incremental encoder, which makes it possible to count the number of turns of the cable winding unwound, and therefore to deduce the water depth at the anchor; a sonar module, which makes it possible to detect a variation in water depth and to deduce a possible movement of the anchor; a force sensor.

[0084] In particular, the buoy 21 may include an accelerometer that measures the displacement of the buoy 21 by double integration of the acceleration. An accelerometer is a sensor that measures the linear acceleration along three axes of an object to which it is attached or incorporated. Linear acceleration refers to the changes in speed of an object per unit of time. This sensor makes it possible to avoid the drift of the double integration, only acceleration values ​​above a certain threshold will be considered.

[0085] The instructions of the software implemented in the memory 213, when executed by the processing unit 214, make it possible to carry out steps of the method which are claimed and / or described further in the description. The software may include management of solar charging and induction charging, and management of the lighting of the LED (acronym for light-emitting diode and in English terminology: Light-Emitting Diode, LED). According to an exemplary embodiment, the software detects the precise position of the anchor 22. This makes it possible to warn the user of a possible skid.

[0086] The buoy 21 communicates with a mobile terminal 3. In particular, the communication interface 215, for example GSM, 2G, 3G, 4G, 5G, Bluetooth®, or Wifi®, is suitable for establishing a wireless communication link with the mobile terminal 3 described further in the description, through a data network.

[0087] The software comprises radio communication with a receiving antenna of the receiving box 25 of the boat 20. According to one example, the communication with the mobile terminal 3 is made by mobile data. According to a variant, the mobile terminal 3 is a telephone.

[0088] Referring to Figure 4, the position sensor 210, the transmitter 211 and the other possible electronic resources 212-215, are preferably installed in a removable waterproof housing 29 detachably attached to the hull 28 of the buoy 21. When installed, the waterproof housing 29 is located in the upper part of the buoy 21, preferably above the waterline. The detachable attachment means are advantageously magnets, clips or any other equivalent means suitable to the person skilled in the art and not requiring special tools. A padlock or a lock may also be provided to prevent malicious disassembly of the housing 29.

[0089] The possibility of separating the housing 29 - containing fragile electronic components - from the hull 28 has several advantages. First of all, this configuration makes it possible to protect the electronic components against risks of deterioration linked to unfavorable environmental conditions when the buoy is not in service, such as prolonged humidity, temperature variations or salt water projections. In addition, maintenance and replacement operations of the electronic components are facilitated, since they do not require the transport or complete disassembly of the buoy 21. Finally, the housing 29 can be stored in a protective cover or dedicated storage reducing the risk of theft or damage to the sensitive components, while the buoy is stored in a conventional manner in a storage box or in the hold of the boat. Description of the receiving box 25.

[0090] The receiving box module 25 comprises a transmitter and a receiver. According to one embodiment, the receiving box 25 comprises the following technical characteristics: a radio antenna, a microcontroller, a memory. In one example, the receiver box has a user interface. In one example, power is provided by a battery. The power autonomy of the receiver box 25 lasts approximately two to ten days. In another example, the power supply is connected to the boat's power supply.

[0091] In Figure 5, the receiving box 25 integrates a data receiver 250. If necessary, the box 25 can also integrate a satellite position sensor 251, one or more memories 252 in which software is recorded, a processing unit 253, a communication interface 254 and / or a user interface 255.

[0092] The receiver 250 is adapted to exchange data with the transmitter 211 of the buoy 21, via the aforementioned short-range wireless link. It is preferably in the form of a radio antenna. The data exchanged may be the position data of the satellite position sensor 210 of the buoy 21, and possibly the data of the other sensors 212 and / or the data relating to the steps a) to d) claimed. According to one embodiment, the radio antenna 250 comprises the same technical information as the radio antenna 211 of the buoy 21.

[0093] The satellite position sensor 251 is preferably a GNSS sensor and / or includes the same characteristics and functionalities as those mentioned above relating to the position sensor 210 of the buoy 21.

[0094] The software instructions stored in the memory 252, when executed by the processing unit 253, enable steps of the method to be carried out which are claimed and / or described further in the description.

[0095] The communication interface 254, for example GSM, 2G, 3G, 4G, 5G, Bluetooth® or Wifi®, is adapted to establish a wireless communication link with the mobile terminal 3, via a data network. According to one example, the communication with the mobile terminal 3 is made by mobile data.

[0096] According to one embodiment, the user interface 255 comprises a touchscreen. According to another example, the user interface comprises a screen alphanumeric and is backlit. According to an exemplary alphanumeric display, it has two lines and sixteen characters. The backlight or lights are configured to indicate the status of the anchor 22 and indicate the battery level of the receiving box 25. According to an exemplary embodiment, the receiving box 25 is sized according to the following measurements: twelve to sixteen centimeters in length, ten to sixteen centimeters in width, and three to five centimeters in height. The receiving box 25 is recharged via a USB port. The term USB is an English term meaning "Universal Serial Bus", in French it means "Universal Serial Bus" and includes different versions (e.g.: USB 1.0, 2.0, 3.0, 3.1, 3.2, USB4) as well as different types of physical connectors, including USB-C. It is a connectivity standard widely used to connect peripherals to computers and other electronic devices. Description of some features

[0097] According to one embodiment, the anchor 22 can have three states defined by the position of the buoy 21: a “stabilizing” state, a “stable” state and a “skidding” state. These different states are determined by the buoy 21 or by the receiving box 25, depending on whether one or the other has the electronic resources provided for this purpose. In the “stabilizing” state, the anchor 22 is hooking. It does not have a stable position for a determined period (for example for 3 minutes). In the “stable” state, the anchor 22 is hooked, its position being stable beyond a determined period (for example beyond 3 minutes). By “stable position”, it is meant that the position of the anchor 22 remains within a determined perimeter as explained further in the description. In the “skidding” state, the anchor 22 initially in a “stable” state, skids on the seabed and leaves its stable position.In this case, the alarm signal is generated.

[0098] The initial position of the anchor 22 preferably corresponds to its position in the “stable” state, but could correspond to its position as soon as the location function is activated, for example when activating the buoy 21 or the receiving box 25. This initial position can be determined by buoy 21 or by the receiving box 25, depending on whether one or the other has the electronic resources provided for this purpose.

[0099] According to one embodiment, the change in position of the anchor 22 is determined during a regular time interval. The starting point of this interval may correspond to the moment of activation of the location function of the anchor 22, in particular during the activation of the buoy 21 or the receiving box 25 as soon as the anchor is put into the water, or correspond to the moment when the anchor 22 has a stable position. The end of this interval corresponds to the moment of deactivation of the location function of the anchor 22, for example during the deactivation of the buoy 21 or the receiving box 25 once the anchor is brought back on board.

[0100] The buoy 21 sends to the receiving box 25, via its radio antenna 211, its position and / or its state at regular time intervals, for example every five seconds, every five minutes, every hour, etc. This transmission interval can be re-parameterized or adjustable from the user interface 255 of the receiving box 25. For example, if the boat 20 is at anchor in a very busy area, it may be advantageous to have a high transmission frequency (for example a transmission every five seconds) to be quickly alerted in the event of the anchor 22 slipping. Conversely, if the boat 20 is at anchor in a little or not busy area, the transmission frequency can be lowered (for example a transmission every five minutes or every hour) to the extent that a possible slipping of the anchor 22 does not present any particular risk.The electronic resources of buoy 21 and box 25 (in particular their battery) are, in this case, more preserved.

[0101] The data provided by the GNSS sensor 210 of the buoy 21 generally includes latitude, longitude and a timestamp. According to one embodiment, the GNSS sensor 210 is configured to also provide the number of satellites used for calculating its position and / or a value of HDOP (for the English acronym for “Horizontal Dilution of Precision”). The HDOP is a factor of dilution of precision (DOP) which measures the geometric quality of the satellites for calculating the horizontal position (latitude and longitude). Typically the HDOP value is between 0 and 5. The lower the HDOP, the better the position accuracy.

[0102] According to a preferred embodiment, the GNSS sensor 210 of the buoy 21 calculates its position after a filtering step implemented to keep only the position data transmitted by the satellites whose HDOP value is less than or equal to a threshold value, advantageously an HDOP < 2 and preferably an HDOP < 1. This filtering makes it possible to improve and make more reliable the precision of the calculation of the position of the GNSS sensor 210 and therefore of the buoy 21. This threshold value can be re-parameterized or adjustable from the user interface 255 of the receiving box 25. For example, if the boat 20 is at anchor in a very busy area, it may be advantageous to have very good precision of the position of the buoy 21 to be alerted quickly in the event of the anchor slipping or beyond a reduced perimeter. In this case, the threshold value can be set to an HDOP < 1.Conversely, if the boat 20 is at anchor in a little or no frequented area, a less precise position of the buoy 21 may suffice. In this case, the threshold value can be set to an HDOP < 2, or an HDOP < 4, or even a deselection of the filtering function. The electronic resources of the buoy 21 and the box 25 are in this case more preserved.

[0103] According to an embodiment making it possible to further optimize the precision and reliability of the calculation of the position of the buoy 21, and to make it more robust, the GNSS sensor 210 calculates its position by combining the data transmitted by a determined number of satellites, preferably at least ten satellites.

[0104] According to one embodiment, the user can, via the user interface 255, define a perimeter beyond which the buoy 21 must not leave, otherwise the anchor 22 is skidding on the seabed. As soon as the buoy 21 leaves this perimeter, the alarm signal is generated. In Figure 6, this perimeter is represented diagrammatically by a circle of radius R (or avoidance radius) and whose center corresponds to the initial position of the buoy 21, preferably as soon as the position of the anchor 22 is stable. From the interface 255, the user can for example select different values ​​of the radius R, for example between 1 m and 20 m. The interface 254 may also present the user with different selectable modes that automatically define a value of the radius R. For example, a "normal" mode automatically defines a radius R = 10 m, a "restricted" mode a radius R = 5 m, and a "wide" mode a radius R = 20 m.

[0105] A radius R of between 1 m and 5 m can be selected in particular when the boat 20 is at anchor in a busy area. The user is thus quickly warned that the anchor 22 is slipping so that he can act promptly to avoid a possible collision with another boat. Conversely, a radius R greater than 10-15 m can be selected when the boat 20 is at anchor in a little-used area, slipping of the anchor 22 in this perimeter being tolerated in this case, without generating any particular risk.

[0106] Referring to Figure 1, it may be advantageous to calculate the distance D between the buoy 21 and the boat 20. Knowing this distance makes it possible in particular to warn the user in the event of breakage of the mooring line 24, generally a chain. The distance D is determined by the buoy 21 or by the receiving box 25, depending on whether one or the other has the electronic resources allowing it. The distance D can in particular be calculated by the difference in the positions of the position sensors 210 and 251. According to another embodiment, a radiofrequency signal is emitted between the buoy 21 and the box 25 (via their respective transmitter / receiver), the distance D being determined by calculating the round-trip time of this signal.

[0107] According to one embodiment, the receiving box 25 transmits control instructions to activate the buoy 21 and / or to activate, adjust or configure the functionalities of said buoy. For example, the box 25 can transmit to the buoy 21 control instructions to activate / deactivate it, to activate / deactivate the anchor location function 22, to adjust the transmission frequency of the position of the buoy, to adjust the threshold value of the HDOP, to adjust the value of the radius R, etc. According to another embodiment, these control instructions are directly generated from a user interface of the buoy 21. According to yet another embodiment, these control instructions are transmitted from the mobile terminal 3 and transmitted to the buoy 21 and / or to the receiving box 25.

[0108] Naturally, the invention is described in the above by way of example. It is understood that those skilled in the art are able to carry out different variant embodiments of the invention without departing from the scope of the invention.

[0109] It is emphasized that all features, as they emerge for a person skilled in the art from this description, the drawings and the attached features, even if they have been specifically described only in relation to other specific features, both individually and in any combinations, may be combined with other features or groups of features disclosed herein, provided that this has not been expressly excluded or that technical circumstances make such combinations impossible or meaningless.

[0110] In other words, one or more features disclosed only in one embodiment may be combined with one or more other features disclosed only in another embodiment. Similarly, one or more features disclosed only in one embodiment may be generalized to other embodiments, even if that or those features are described only in combination with other features.

Claims

Claims

1. [Method for determining the position of an anchor (22), characterized in that the method comprises the following steps: -a) determining the initial position of an anchor (22) connected to a boat (20) and to a buoy (21); said buoy (21) is connected to the anchor (22) by a cable (23) comprising an automatic reel configured to tension the cable (23) between the buoy (21) and the anchor (22), said initial position of the anchor (22) being determined by a satellite position sensor (210) of said buoy (21); -b) determining the displacement of said anchor (22) by the satellite position sensor (210) of said buoy (21); -c) determining during a regular time interval the change in position of the anchor (22) using the sensor from the previous step; -d) receiving, on a receiving box (25) positioned on said boat (20), data coming from the satellite position sensor (210) of the buoy (21) and / or a status signal of the anchor (22), said data or said signal being received via a data receiving antenna (250) belonging to said receiving box, said data and / or said signal being emitted by a radio transmitter (211) of said buoy; -e) sending a message of the position of the anchor (22) to a mobile terminal (3).

2. The method of claim 1, wherein the satellite position sensor (210) of the buoy (21) is a GNSS position sensor.

3. Method according to one of the preceding claims, wherein during step b), the displacement of the anchor (22) is further determined by an accelerometer.

4. Method according to one of the preceding claims, in which during step b), the movement of the anchor (22) is determined by sensors of the buoy (21).

5. Method according to claim 4, in which the sensors (212) are of the following family: an accelerometer; a shock sensor configured to detect a shock between another boat and the buoy; a motion sensor, for example by infrared configured to detect if another boat is close to the buoy; an incremental encoder configured to count the number of turns of cable winding (23) unwound; a sonar module configured to detect a variation in water depth and to deduce a possible movement of the anchor; a force sensor.

6. Method according to one of the preceding claims, in which the automatic reel is configured to have a constant tension of the cable (23) between the buoy (21) and the anchor (22).

7. Method according to one of claims 1 to 6, in which step b) and step c) are implemented in the receiving box (25).

8. Method according to one of claims 1 to 6, in which step b) and step c) are carried out in the buoy (21).

9. Method according to one of the preceding claims, comprising a step of configuring the buoy (21) or the receiving box (25) to determine different states of the anchor (22): - a “stabilizing” state during which the anchor (22) does not have a stable position for a determined period, - a “stable” state during which the anchor (22) has a stable position beyond a determined period, - a “skidding” state, in which the anchor (22), initially in a “stable” state, leaves its stable position.

10. Method according to one of the preceding claims, in which during step e), the message sent to the mobile terminal (3) is an alarm signal generated in the event of a slippage of the anchor (22) observed during step c).

11. Method according to one of the preceding claims, in which during step d), the data coming from the satellite position sensor (210) of the buoy (21) are transmitted at regular time intervals, said interval being adjustable.

12. Method according to one of the preceding claims taken in combination with claim 2, in which the GNSS position sensor (210) of the buoy (21) is configured to provide a value of HDOP and to calculate its position after a filtration step implemented works to keep only position data transmitted by satellites whose HDOP value is less than or equal to a threshold value.

13. The method of claim 12, wherein the threshold value of the HDOP is adjustable.

14. Method according to one of the preceding claims taken in combination with claim 2, in which the GNSS position sensor (210) of the buoy (21) is configured to provide the number of satellites used for calculating its position and to calculate its position by combining the data transmitted by at least ten satellites.

15. Method according to one of the preceding claims, comprising a step of defining, via a user interface (255) of the receiving box (25), a perimeter beyond which the buoy (21) must not leave, an alarm signal being generated as soon as said buoy (21) leaves said perimeter.

16. Method according to claim 15, in which the perimeter is a circle whose center corresponds to the initial position of the buoy (21) and whose radius (R) has an adjustable value.

17. Method according to one of the preceding claims, comprising a step of calculating the distance (D) between the buoy (21) and the boat (20), said distance being calculated: - from data from the satellite position sensor (210) of the buoy (21) and data from a satellite position sensor (251) of the receiving box (25), or - by calculating a round trip time of a radiofrequency signal emitted between the buoy (21) and the receiving box (25).

18. Method according to one of the preceding claims, comprising a step of installing the satellite position sensor (210) and the radio transmitter (211) of the buoy (21) in a removable waterproof housing (29), and a step of detachably fixing said housing (29) on the hull (28) of said buoy (21).

19. Method according to one of the preceding claims, comprising a step of equipping the buoy (21) with at least one of the following elements: a visual indicator, a luminous ribbon, a handle (26).

20. Method according to one of the preceding claims, comprising a step of equipping the buoy (21) with a photovoltaic panel (27) or a battery and an induction charger configured to power the elements in said buoy (21).

21. Method according to one of the preceding claims, in which during step d), the receiving box (25) comprises a user interface (255) configured to consult the data coming from the sensors (212).

22. Method according to claim 21, wherein during step d), the user interface (255), the receiving box (25) or the buoy (21) comprises an alert in the event of slippage of the anchor (22).]

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