Inspection methods in conductive media

Abstract

This method uses a detection system to locate or identify objects in a conductive medium, comprising n electrodes in direct electrical contact with the conductive medium. These n electrodes are capable of being in at least three different states: transmitting, receiving, and disconnected. Prior to a series of measurements, the operating point of the detection system is determined based on a pre-given setpoint, a previous system configuration, or previous measurements of one of the electrodes, by the configuration state of each electrode, the frequency of the sinusoidal component of the electrical signal emitted by one of the transmitting electrodes, or the amplitude of the electrical signal emitted by one of the electrodes configured in the transmitting or receiving state.

Description

Technical Field

[0001] This invention relates to a method for detection in a conductive medium. Background Technology

[0002] More specifically, the present invention relates to a method for detection in a conductive medium using a system comprising multiple electrodes, which allows the use of electroinduction, i.e., the generation of an electric field through certain electrodes, and the acquisition of information about the conductive medium itself or about an object located in the conductive medium by measuring electrical parameter values ​​associated with this electric field.

[0003] In the field of detection in conductive media, it is known to measure electrical parameter values ​​by receiving electrodes in order to infer information about the presence or geometric parameters of objects or boundaries in the conductive medium, such as the shape of these objects or boundaries and their orientation, without prior knowledge of these geometric parameters.

[0004] For example, document WO2013014392A1 describes a method for controlling the movement of a mobile system in a conductive medium, the system comprising at least one electrode in contact with the medium. This method specifically includes a step of measuring the electrical properties of the medium—more specifically, the current intensity—through this electrode, hence the designation as a receiver-type electrode. In a particular embodiment, this control method provides a step that may automatically manage the electrical connections of electrodes, which may be generator-type and / or receiver-type electrodes, with the aim of optimizing the detection range or positioning accuracy of the mobile system relative to a detected object.

[0005] However, the method described in WO2013014392A1 aims to optimize the management of the movement of a movable system. The management of the electrical connections of the electrodes is based on the movement of the movable system. Specifically, three connection modes are defined: an attraction mode, which allows approach to the object; a repulsion mode, which allows movement away from the object; and an object boundary following mode, which allows movement along the object. It is also possible to configure the electrodes in the mode that optimizes the detection range.

[0006] However, the measured electrical parameter values ​​(amplitude of voltage or electrical intensity at a fixed frequency) and the possible states of the electrodes (generator type, transmitting, or connected to a terminal shared by several electrodes (referred to as terminal B1 in this document)) cannot maximize the performance of the mobile system for sensing values ​​of interest beyond the detection range or positioning accuracy, such as the shape, size, or material properties of the object being detected.

[0007] Therefore, the object of the present invention is a method for detection in a conductive medium, which may be implemented independently of a mobile system, making it possible to dynamically and automatically optimize the performance of the detection system in terms of detection range or object positioning, or in terms of determining the shape or properties of the object. Summary of the Invention

[0008] Therefore, the present invention relates to a method for detection in a conductive medium by means of a detection system comprising a plurality of electrodes in direct electrical contact with the conductive medium.

[0009] The detection system includes:

[0010] - Multiple electrodes (E) that are in direct electrical contact with the medium i Its status can be selected from the list {transmit, receive, disconnect}.

[0011] - A means for measuring at least one electrical parameter value of each electrode configured in a transmitting or receiving state, selected from the list {electrical intensity of the electrode, electrical potential of the electrode}.

[0012] - A switching device that can configure each electrode in the electrode array to a state selected from the list {transmit, receive, disconnect}.

[0013] - At least one processor for exchanging information with the measuring device and the switching device.

[0014] The method includes the following steps:

[0015] a. The processor determines the operating point of the detection system based on the following:

[0016] -Pre-defined setpoint,

[0017] - and / or the previous configuration of the detection system

[0018] - and / or previous measurement results at at least one of the electrodes transmitted by the measuring device,

[0019] Determining the operating point of the detection system involves determining the following three parameters:

[0020] - The state of each electrode in the electrode array is selected from three states: transmit, receive, or disconnected.

[0021] - The frequency of at least one sinusoidal component of an electrical signal emitted by at least one electrode arranged in the transmitting state.

[0022] - The amplitude of an electrical signal emitted by at least one of the electrodes configured in the emission state;

[0023] b. The switching device receives information about the system's operating point as determined by the processor and configures the detection system at the determined operating point;

[0024] c. A series of measurements are performed by the measuring device, the series of measurements including evaluating at least one electrical parameter value at each electrode configured in the receiving or transmitting state, and the measuring device transmits the measurement data to the processor.

[0025] Because of these arrangements, it is possible to automatically and dynamically configure the states of different electrodes to maximize detection performance relative to the detection target determined before each series of measurements. For example, the target could be, for instance, optimizing the detection range in one or more spatial directions, or the positioning accuracy of the detected object, or the accuracy of identifying the shape and / or properties of the object.

[0026] In one embodiment, the detection method further includes an additional step, referred to as step d, during which the processor calculates at least one plotting data of the conductive medium based on the measurement data.

[0027] Because of this arrangement, the detection system can provide a map of all or part of the space around it at the end of a series of measurements. This map can then be used to move the movable system.

[0028] In one embodiment, the steps of the method are repeated at least once in the same order, and a setpoint is transmitted to the processor to control the repetition of the steps, either by a remote or non-remote operator before the first step a of the detection method, or by a remote operator during the detection method.

[0029] Because of this arrangement, the map provided by the detection system can be enhanced by additional information derived from a continuous series of measurements and can potentially be adjusted in real time. This map can then be used to move the movable system or to track the evolution of the properties and / or positions of one or more objects in the surrounding space.

[0030] In one embodiment of the method, the operating point of the system determined in step a can be selected from a list {"boundary" mode, "positioning" mode, "recognition" mode}, where the "boundary" mode allows for the maximum detection range in one or more given directions of the medium, the "positioning" mode allows for the maximum accuracy in the positioning of previously detected objects, and the "recognition" mode allows for the optimal resolution in terms of the shape and / or composition of previously detected objects.

[0031] In one embodiment of this method, the operating point of the detection system automatically moves from step a to the next step:

[0032] - When an object is detected and it is located at a distance less than the threshold distance d2, switch from "boundary" mode (if it is in this mode) to "location" mode.

[0033] - When an object is detected, and this object is located at a distance less than the threshold distance d3, or has a shape and / or properties corresponding to the set point, switch from "Location" mode (if it is in this mode) to "Recognition" mode.

[0034] - When an object is detected and the distance to the detected object is greater than the threshold distance d2, switch from "Location" mode (if it is in this mode) to "Boundary" mode.

[0035] These arrangements allow the detection system to automatically switch from boundary mode to positioning mode when it approaches the object being detected, then to recognition mode when it gets even closer to the object, and finally back to boundary mode if it moves away from the object after entering positioning mode.

[0036] In one embodiment of the method, the shape and / or frequency and / or amplitude of the signal emitted by the electrode configured in the emission state for the operating point determined in step a are selected at the end of the frequency scan.

[0037] This arrangement allows for the determination of the optimal operating frequency for an upcoming series of measurements without prior knowledge of the surrounding space.

[0038] In one embodiment of the method, the signal emitted by at least one of the electrodes configured in the emission state for the operating point determined in step a is a combination of at least two sinusoidal signals with different frequencies.

[0039] Because of this arrangement, information corresponding to each frequency in the frequency range is collected, and it allows for the detection of specific elements in the surrounding space, such as the interface between two different media.

[0040] In one embodiment of the method, if an object is detected in step d, the amplitude and / or shape and / or frequency of the sinusoidal component of the electrical signal emitted by each of the electrodes configured in the emission state for the operating point determined in the subsequent step a is determined based on the distance to the detected object.

[0041] This arrangement also allows for the gradual construction of a map of the surrounding space, or the dynamic movement of the mobile system, i.e., optimizing the working points of an upcoming series of measurements based on the detection results of the last series of measurements performed.

[0042] In one embodiment of the method, if an object is detected in step d, the operating point determined in subsequent step a is configured such that the position of the electrode in the emission state on the system is determined based on the shape and / or position of the detected object.

[0043] This arrangement allows for the gradual construction of a map of the surrounding space, or for the dynamic movement of the mobile system, i.e., optimizing the working points of an upcoming series of measurements based on the detection results of the last series of measurements performed.

[0044] In one embodiment of the method, a known reference is used to determine at least one piece of drawing data in step d.

[0045] Because of this arrangement, graphs, for example, including electrical object characteristics, can be used to infer the properties of the object being detected.

[0046] Accordingly, the present invention relates to a computer program that includes, when executed on a computer,

[0047] Program code instructions used to execute the steps of the detection method.

[0048] The present invention also relates to a system for detection in a conductive medium, comprising:

[0049] - Multiple electrodes (E) that are in direct electrical contact with the medium i Its status can be selected from the list {transmit, receive, disconnect}.

[0050] - A measuring device for measuring at least one electrical parameter value of each electrode configured in a transmitting or receiving state, selected from the list {current intensity through the electrode, electrode potential}.

[0051] - A switching device that can configure each electrode in the electrode array to a state selected from a list {transmit, receive, disconnect}.

[0052] - At least one processor, which exchanges information with the measuring device and the switching device, and is configured to determine the operating point of the detection system based on the following:

[0053] -Pre-defined setpoint,

[0054] - and / or the previous configuration of the system,

[0055] - and / or previous measurement results at at least one of the electrodes transmitted by the measuring device.

[0056] Determining the system's operating point involves determining the following three parameters:

[0057] - The state of each electrode in the electrode array is selected from at least three states: transmit, receive, disconnect.

[0058] - The frequency of at least one sinusoidal component of an electrical signal emitted by at least one of the transmitting electrodes.

[0059] - The amplitude of an electrical signal emitted by at least one of the electrodes configured in the emission state;

[0060] Information about the determined working point is transmitted to the processor of the switching device.

[0061] In one embodiment, the mobile system further includes a control module configured to control the movement of the mobile system based on measurement results obtained by the detection system according to the detection method of one of the above embodiments.

[0062] Because of this arrangement, the mobile system can move without prior knowledge of its operating environment.

[0063] In one embodiment of the mobile system, the electrodes of the detection system equipped with the mobile system are distributed on at least a portion of the surface of the mobile system in contact with the medium. Attached Figure Description

[0064] Embodiments of the present invention will be described below with reference to the accompanying drawings, and are briefly described as follows:

[0065] Figure 1 An embodiment of a mobile system equipped with a detection system having electrodes distributed on its surface that come into contact with an external medium is shown.

[0066] Figure 2 The electrical structure of the switching box is shown;

[0067] Figure 3 An example of a switching unit for a given electrode is shown in detail;

[0068] Figure 4 The circuit of the unit corresponding to electrodes i and j in the connected state is shown, where electrode i is in measurement mode U and electrode j is in measurement mode I;

[0069] Figure 5 This illustrates the proportion of time the electrodes are activated, depending on their position on the detection system, in a simplified case within a two-dimensional medium, under the "isotropic" bounded mode. In this particular example, the detection system is immovable in the conductive medium.

[0070] Figure 6 This illustrates the time proportions during which the electrodes are activated, depending on their positions on the detection system, in a simplified case within a two-dimensional medium under the "anisotropic" bounded mode. In this particular example, the detection system is in a linear translational state within the conductive medium.

[0071] Figure 7This illustrates the time proportions during which the electrodes are activated, depending on their positions on the detection system, in a simplified case of a detection system within a two-dimensional medium, under the "anisotropic" bounded mode. In this particular example, the detection system rotates about one of its axes of symmetry.

[0072] Figure 8 An algorithm that can implement calibration mode is shown;

[0073] Figure 9 An algorithm that can implement bounded patterns is shown;

[0074] Figure 10 An algorithm that can implement positioning mode is shown;

[0075] Figure 11 An algorithm capable of recognizing patterns is shown;

[0076] Figure 12 The different stages of the system in the "centralized electronic device" embodiment are illustrated schematically;

[0077] Figure 13 The different stages of the system in the "centralized electronic device" embodiment are illustrated schematically.

[0078] In the accompanying drawings, the same reference numerals denote the same or similar objects. Detailed Implementation

[0079] Therefore, the present invention relates to a method for detection in a conductive medium using a detection system.

[0080] The detection system implementing this method includes multiple electrodes E designed for direct electrical contact with a conductive medium. i .

[0081] For example, electrode E i The electrodes can be selectively distributed on the outer surface of the movable system 100 equipped with the detection system, so that the electrodes are in direct electrical contact with the conductive medium.

[0082] For example, the conductive medium is water.

[0083] Figure 1 A movable system 100 according to a specific embodiment of the present invention is schematically shown. This movable system 100 includes a parallelepiped with dimensions of 1000mm * 1000mm * 1000mm. The three axes of this parallelepiped, centered at its center O, constitute a spatial reference frame (Oxyz) for the detection system reference frame.

[0084] The detection system has n electrodes E i(where i is an integer between 1 and n) can be distributed on the surface of the movable system 100 to contact the conductive medium. In the specific embodiment described herein, a given electrode E exposed to the conductive medium i The surface is a disk, and 24 electrodes are distributed at the corners and edges of the parallelepiped.

[0085] This embodiment is not limiting. Electrode E i The distribution and / or shape can be adapted to the geometry of the movable system and the conductive medium to be explored. In particular, electrodes can be placed on each face of the parallelepiped.

[0086] The movable system 100 does not have to be parallelepiped. For example, it can be cylindrical or any shape.

[0087] In the case where the movable system 100 includes several parts that can move relative to each other, electrode E i It can be distributed across all of these movable parts or only on a portion of them.

[0088] Electrode E i The number of electrodes can also be adjusted according to the size of the movable system. In the case of a parallelepiped with a reference size of 1000 mm, eight electrodes arranged at the eight vertices of the parallelepiped can, for example, explore all directions of the space around the parallelepiped without leaving any blind spots.

[0089] The electrodes are corrosion-resistant, for example made of 316 stainless steel, or of platinum, titanium, or graphite and carbon fiber, and are arranged on electrically insulating supports, such as PVC supports.

[0090] According to Figure 12 In the embodiment of the "centralized electronic device", electrode E i It is electrically connected to a sealed housing approximately 10 centimeters in size via a bundle of flexible cables.

[0091] In the embodiments described herein, the housing includes:

[0092] - A setpoint generation block, comprising a microprocessor, a read-only memory containing a computer program executable by the microprocessor, a random access memory that can execute the program, and means for transmitting setpoints to the switching box and for receiving information from the switching box.

[0093] - A switching box (or equivalent switching block) comprising as many switching units as electrodes, and implementing switching according to... Figure 2 The electronic and electrical components required for the circuit.

[0094] Each switching unit is dedicated to one electrode and can include a generator for each electrode, a device for measuring electrical parameter values, and a means of implementing [the function] based on [the specific electrode]. Figure 3 The electronic and electrical components required for the electronic circuit. It is also possible for a generator to be shared among several electrodes, or even all electrodes.

[0095] Therefore, for electrode E i Switch S 3i Electrode i can be in a connected or disconnected state. If the electrode is connected, it can be switched via S. 1i Set it to transmit or receive mode.

[0096] Therefore, given electrode E i It can be in three different states: transmitting (and thus connecting), receiving (and thus connecting), and disconnecting.

[0097] In this case, switch S 2i Configure the electrodes to either measurement mode I or measurement mode U as defined below.

[0098] Switch S 1i S 2i S 3i It can be controlled by a setpoint generation box, allowing the state of each electrode to be freely configured at each step of the method.

[0099] In this embodiment, the switching box requires no manual intervention. Therefore, electrode reconfiguration can be performed remotely and automatically, as will be described below. In particular, when the detection system is immersed in a conductive medium, the electrodes can be automatically reconfigured without changing the position of the detection system or the movable system 100 equipped with it.

[0100] The sealed housing of the detection system can be used as is, or integrated into the movable system 100 in which it is assembled, or placed on the outer surface of such movable system 100.

[0101] For example, it can be used in the context of monitoring vibrations in stationary structures such as crude oil extraction infrastructure.

[0102] Electrode E configured in the emission state i It is connected to a suitable voltage generator so that the amplitude, frequency and / or shape of the electrode potential can be applied within the range allowed by the voltage generator.

[0103] Choosing the amplitude of the potential of the electrode in the transmitting state is equivalent to choosing the electrical power provided by the generator connected to that electrode. For simplicity, it can be said synonymously as "choosing the power of the signal emitted by the transmitting electrode".

[0104] The amplitude, frequency, and / or shape of the potential of an electrode can be applied to each electrode in the emission state independently of other electrodes in the emission state.

[0105] For example, it is possible to provide a generator for each electrode.

[0106] In another embodiment, the same generator can be connected to several electrodes in the emission state.

[0107] By way of non-limiting examples, the amplitude of this potential can be selected in the range of [0V, 15V], and its frequency can be selected in the range of [0Hz, 3MHz]. The shape of the potential can be, for example, a sine wave, a square, or a triangle. The potential can be periodic, or consist of only one or more pulses.

[0108] When multiple generators are provided, all generators connected to electrodes in the emission state are activated simultaneously.

[0109] Each of the transmitting electrodes generates an electric field in the surrounding space. A portion of these electric fields eventually appear on the electrodes in the receiving state. This portion depends on the transmitting / receiving electrode dipoles under consideration, that is, on the relative positions of the pair of transmitting and receiving electrodes under consideration.

[0110] The electric fields generated by all the electrodes are superimposed to form the resulting electric field, the topography of which depends not only on the position and shape of the transmitting electrodes and their potentials, but also on the position and shape of the receiving electrodes (whose potential is the ground potential), and the position and shape of the disconnected electrodes.

[0111] In the off state, electrode E i It is not electrically connected to any component of the detection system or movable system. Specifically, it is connected to two different electrodes E that are simultaneously in an open state. i They will not connect to each other. Disconnected electrode E i It is permissive, meaning it utilizes the potential of the medium it comes into contact with. Its potential is not imposed. The electrode is freely polarized according to its environment.

[0112] Furthermore, the open state prevents current from passing through the electrode in this mode because it is not integrated into a closed circuit. Therefore, the existence of this mode makes it possible for a receiving electrode to effectively receive current.

[0113] Therefore, the presence of the disconnected state provides the detection system with more possible perspectives compared to the absence of this mode.

[0114] The diversity of possible combinations of electrode types is one of the factors that allows for the optimization of the detection system relative to the target being sought.

[0115] As described below, between two consecutive series of measurements (the concept of series of measurements will be defined below), the reconfiguration of the electrodes, i.e. the reconfiguration of the system's operating point, makes it possible for the topography of the electric field generated by the detection system in the surrounding scene to change from one series of measurements to the next.

[0116] For example, an anisotropic electric field will provide different information about the scene than an isotropic electric field. Two anisotropic electric fields with different terrains will provide different information, even if the detection system does not change its position and / or orientation.

[0117] The presence of the disconnected state makes it possible, in particular, to explore specific directions of the conductive medium by generating an electric field of significant intensity in that specific direction, which is determined by the electrode that is not in the “disconnected” state.

[0118] The existence of the disconnected state makes even such Figure 1 The electrodes shown are distributed across all surfaces of the movable system, allowing the definition of a detectable electric field within a terrain exhibiting very strong anisotropy. For example, it is possible to disconnect all electrodes except those on one surface. In this case, only the electrodes on that surface may have current flowing through them.

[0119] The electrode configured in the receiving state can be configured for two different measurement modes:

[0120] - Measurement Mode "I": In this mode, the potential of the electrode is imposed and equal to the system's ground potential. The measured electrical parameters are the current intensity flowing to the receiving electrode, i.e., its phase and amplitude. For this purpose, N intensity measurements are performed for each period of the signal over P periods. If the signal contains several sinusoidal components, a bandpass filtering step adapted to the different components to be studied is performed, thereby measuring the phase and amplitude of each component of the electrical intensity passing through the receiving electrode. The potential difference between the transmitting and receiving electrodes involved in this case is imposed and therefore known, which ultimately allows the impedance value for each frequency to be derived from the measurements.

[0121] - Measurement Mode "U": In this mode, the potential at the receiving electrode is floating. The current intensity through the transmitting electrode and the potential at the receiving electrode are measured, i.e., their respective phases and amplitudes are measured. For this purpose, N intensity (voltage) measurements are performed for each of the P cycles of the signal. If the signal contains several sinusoidal components, a filtering step with a bandpass adapted to the different components to be studied is performed through an electronic filter, thereby measuring the phase and amplitude of each component of the current intensity through the transmitting electrode (which is the potential at the receiving electrode).

[0122] The filtering stage is placed at the input of the setpoint generation box, so that different components of the digital signal derived from the analog-to-digital conversion of the measuring device are filtered before the data are processed to obtain information about the position, properties or shape of the detected object.

[0123] Figure 4 An example of an operating point is given, electrode E i and E j They are connected, and in measurement mode I, the first one is in the transmitting state and the second one is in the receiving state.

[0124] Each of the N measurements requires a specific "time unit," which depends on the electronic equipment chosen effectively to realize the detection system.

[0125] Once each of the N*P measurements for each component of the signal has been effectively performed, the series of measurements is complete. Therefore, the series of measurements includes the evaluation of at least one electrical parameter value (in terms of electrical strength and potential) at each electrode configured in the receive or transmit state.

[0126] The system's operating point is determined before each series of measurements by the electrode configuration, particularly by configuring the following three parameters:

[0127] - The state of each electrode in the electrode is selected from at least three states: transmit, receive, disconnect;

[0128] - The frequency of a component of an electrical signal emitted by at least one of the transmitting electrodes;

[0129] - The amplitude of an electrical signal emitted by at least one of the electrodes configured in the emission state.

[0130] Then, the characteristic impedance of the conductive dielectric portion between the emitter and receiver electrodes of a given receiver / emitter electrode dipole is derived from the potential difference between the two electrodes and the current through one of them at each operating frequency. These impedances can then be used by the detection system to obtain parameters characterizing the object being detected (or the absence of an object).

[0131] Therefore, it is understood that in this invention, the concept of detection includes one and / or the other of the following two aspects: locating and characterizing an object. Thus, perception can be referred to synonymously.

[0132] When a series of measurements are performed, the impedance to the transmit / receive electrode dipole formed at a selected operating point can be evaluated for each operating frequency.

[0133] The detection system can control the amplitude to protect the electrodes: if the current intensity of one of the electrodes detected in measurement mode I is greater than the set value, the ongoing series of measurements will stop, and at the next operating point, the voltage amplitude of the generator terminal connected to the electrode in the emission state will be reduced.

[0134] The results regarding the location and / or shape and / or properties of potentially detected objects, or the fact that no object was detected, may ultimately be used by the setpoint generation box of the detection system to determine the system's operating point for the next series of measurements, for example, according to... Figures 9 to 11 The algorithm is represented in the text.

[0135] According to one embodiment, in this detection method, the operating point of the system can be selected to correspond to a "limit" mode. In this case, the electrode assembly in either the transmitting or receiving state is determined based on the direction from which the maximum detection range is desired, i.e., the distance at which the object can be detected is maximized for the rated operation of the electrical components of the circuit.

[0136] exist Figure 5 In a specific embodiment of the boundary mode represented by the simplified version, the distribution of electrodes in the three states of transmitting, receiving, and disconnection is "isotropic," that is, given the electrodes E of the detection system... i The positions are made as isotropic as possible. In this distribution, no spatial direction is privileged.

[0137] For example, in mobile system 100 Figure 1 When equipped with a detection system, the measurement in boundary mode can be repeated 6n times. In these six series of n-series measurements, only the electrodes on the interior, edges, and / or corners of one of the six faces of the parallelepiped can be in an emitting state each time, and these six faces are continuously scanned.

[0138] therefore, Figure 5 The diagram illustrates the electrode activation time assigned to each of the four faces of a simplified rectangular movable system equipped with a detection system in a simplified two-dimensional case.

[0139] In bounded mode, the voltage amplitude at the transmitting electrode can be within the range of [0, 15V]. The shape and frequency of the voltages at all these electrodes are identical. This isotropic bounded mode implementation allows, for example, simultaneous exploration of space within the same range in three directions of the reference frame of a movable system.

[0140] Conversely, if the detection system detects an object in a particular direction, or if a particular direction is of particular interest to the exploration, for example, if the movable system 100 equipped with the detection system makes a translational movement in this direction, the detection system will be able to enter the bounded mode under the "anisotropy" management of the electrodes configured to be in a connected state.

[0141] exist Figure 6 In the simplified example shown, for a detection system equipped with a two-dimensional movable system, if the direction of interest is the [Ox) direction, a portion of the series of measurements greater than 25% (65% in this example) will be performed by activating electrodes on the inner side, edge, and / or corner of the face having the same meaning and direction as [Ox), while a portion greater than half of the remaining measurements (15% in this example) will be performed by activating electrodes on the inner side, edge, and / or corner of the opposite face.

[0142] In a real 3D scenario, n series of measurements will be performed in the bounded mode, such that more than one-sixth of these n series of measurements will be performed by activating electrodes only on the inner side, edge, and / or corner of the face with the same meaning and direction as [Ox], and more than one-fifth of the remaining measurements will be performed by activating electrodes only on the inner side, edge, and / or corner of the opposite face.

[0143] With the detection system provided in the rotating movable system 100, the distribution of the number of measurements performed in different spatial directions can correspond to... Figure 7 The distribution is described in a simplified manner in two dimensions: In this case, the space around the detection system is subdivided into eight parts, with each of four parts being explored separately in one-fifth of the time allocated to the measurement, and each of the other four parts (alternating with the first four parts) being explored separately in one-twentieth of the time allocated to the measurement.

[0144] These examples are non-restrictive, and the flexibility in choosing work points makes it easy to create other variations.

[0145] Because the switching box can automatically reconfigure the electrodes according to the instructions for generating block transmission at the setpoint, the detection system can selectively map all or part of its environment in static mode. To obtain the desired map, i.e., to detect different directions of interest, the detection system or the mobile system 100 equipped with the detection system does not need to move, because the management of the electrode configuration, for example, taking into account previous measurements, allows it to select the direction of exploration and the maximum distance to explore in those directions.

[0146] In bounded mode, the maximum distance that can be detected in at least one given direction is optimized.

[0147] In the limit mode, the amplitude and / or frequency of each sinusoidal component of the signal on the electrodes in the emission state are determined based on the properties of the conductive medium.

[0148] Before the measurement phase of the boundary pattern, it is possible to consider following... Figure 8 The calibration phase of the algorithm. For this purpose, a frequency scan can be performed within the range of [0Hz, 3MHz], repeating n consecutive series of measurements to determine the most suitable frequency [multiple frequencies], maximizing the range within the explored medium. In water, for example, an operating frequency f = 10kHz can be selected.

[0149] This calibration phase can also be used to determine prohibited operating frequencies, particularly the inherent frequencies (and their harmonics) of the mobile system 100 equipped with a detection system. The mobile system 100 in this document includes devices such as sonar.

[0150] In one particular embodiment, frequency scanning can be performed in the range of [0Hz, 25kHz], with lower frequencies often being most relevant to optimizing the detection range.

[0151] Of course, these examples are not limiting: if the composition of the conductive medium is unknown in advance, a frequency scan in the range of [0Hz, 3MHz] can be performed to determine an operating frequency or multiple frequencies that optimize the detection range in a specific direction of the conductive medium.

[0152] If the detection system is located near the water-sediment interface, the potential of the transmitting electrode will more favorably be a combination of two sinusoidal potentials. For example, two sinusoidal potentials with amplitudes between 0 and 15V, one with a frequency equal to 10kHz and the other with a frequency greater than 10kHz, such as 67kHz, can be combined. Signals with higher frequencies will yield better range, especially in sediments. The amplitude is set such that there is as strong a signal as possible on the receiving electrode, but not exceeding the intensity threshold on the electrodes in Measurement Mode I.

[0153] According to one embodiment, in the detection method, the system's operating point can correspond to a "positioning" mode, where the distance between the detection system and the detected object in a given direction continues to be measured with maximum accuracy relative to a specific distance value of the object, while maintaining a rated operating mode. In this case, the position of the electrodes configured in the transmit or receive state is determined, for example, based on the orientation of the object that has already been detected.

[0154] In a particular embodiment, the amplitude and / or frequency of the sinusoidal component of the signal are determined on the electrodes in the transmitting state to optimize positioning accuracy. The amplitude of the signal can be determined, in particular, based on the position and properties of the object being detected; specifically, a maximum amplitude value can be selected such that the amplitude relative to the position and properties of the object being detected does not exceed the maximum permissible intensity on the receiving electrodes.

[0155] The signal frequency can be selected after frequency scanning. Therefore, when an object is present in the conductive medium, due to the skin effect, if the object is located within the detection area corresponding to the selected operating point, the measured signal will be different from the signal when no object is present. At low frequencies, the range is larger than at high frequencies, but the positioning accuracy is not as good. As the frequency increases, a threshold frequency appears; above this frequency, the measured signal becomes the same as the signal in a conductive medium without an object. Selecting an operating frequency close to the threshold frequency for positioning yields the highest positioning accuracy.

[0156] This embodiment does not require movement of the detection system (or the movable system 100 equipped with the system) relative to the object being detected, although such movement is still possible. Automatic reconfiguration of the electrodes, particularly the automatic reconfiguration of the frequency of the transmitted signals, is sufficient to obtain the information needed for optimized positioning.

[0157] According to one embodiment, the detection method can determine the operating point of the system in order to correspond to the “recognition” mode, that is, to determine the shape and / or properties of the detected object with maximum accuracy.

[0158] To more accurately detect the shape of an object of interest, electrodes configured in either transmitting or receiving states are determined based on the orientation of the detected object, and n series of measurements are performed. Only electrodes on the inner sides, edges, and / or corners of surfaces with outward normals corresponding to the direction of interest are connected, and different electrode combinations are traversed across the n series of measurements to infer the shape of the object from the measurements. To confirm the shape of an obstacle, for example, the electrodes are asymmetrically switched from one series of measurements to the next in a given direction. Therefore, it is possible to confirm that an object located beneath the bottom surface of the detection system has a certain extension in the (x'x) direction by continuously grouping and connecting electrodes on the bottom surface in the (x'x) direction, while other electrodes on that surface are disconnected: first the electrode closest to the rear, then their neighbors in the (x'x) direction, until the electrode closest to the front. The differences or similarities between the results of these n series of measurements then allow the inference of the object's shape in the (x'x) direction.

[0159] To confirm the nature of the obstacle, the frequency of the voltage applied to the electrodes in the emission state can be modified, for example, to perform n consecutive series of measurement scans in the range of [0Hz, 3MHz] in "identification" mode.

[0160] This makes it possible to obtain information about the properties of the object being tested. For example, the presence of an electrically insulating object will result in a lower measured current intensity than if the object were not present, while if the object is conductive, the intensity will be greater than if the object were not present.

[0161] For example, a homogeneous mineral object will not cause a phase difference between the transmitted and measured signals, while the presence of a biological object, as long as the cells that make it up behave like capacitors, will cause a phase difference between the transmitted and measured signals.

[0162] It is also possible to obtain information about the object being detected (such as, for example, the object's shape, size, conductivity, or insulation), for example, by comparing the measurement results with known reference data, i.e., a database of objects and the effect of immersing the object in a conductive medium on the electrical signal measured by the detection system, or based on a scenario-based electrical and mechanical evolution model, or by comparing the measurement results with known feature bases, or by information items prepared in advance for the task. These methods are not mutually exclusive.

[0163] In this operating mode, a feature database can be created, known as the "inductive" features of the object of interest (such as mines, cables, and pipes). When the detection system is deployed in situ, it can be compared with the database to infer one or more pieces of information about the object being detected.

[0164] The implementation of the positioning mode does not require (but does not preclude!) movement of the detection system (or a movable system equipped with such a system) relative to the object being detected. Automatic reconfiguration of the electrodes, particularly the automatic reconfiguration of the frequency of the transmitted signals, is sufficient to obtain the information required for identification.

[0165] According to one embodiment, the detection method can be implemented by a computer program executing on a processor integrated into the detection system. Reference will now be made to... Figures 8 to 11 Describe the main steps of this computer program.

[0166] In one particular embodiment, the detection system can be configured to "boundary" mode at the start of detection. Figure 9 A detailed algorithmic example for the "boundary" mode is provided. If the medium conditions are unknown beforehand, the first optional step of the frequency scan, corresponding to the calibration phase, can be performed to determine the optimal operating frequency for this mode.

[0167] When there are no objects in the medium or interfaces with other conductive media, the dielectric impedance is measured using a reference value, which can be given in advance or measured during calibration. The presence of an object or interface changes this impedance, allowing the assessment of the distance to that object or interface.

[0168] The system remains in boundary mode as long as no object or interface is detected within a distance less than the threshold distance d1. If an interface with another medium is detected within a distance less than the threshold distance d1, the frequency scan is repeated.

[0169] Otherwise, if an object is detected at a distance less than the threshold distance d2, the system enters "localization" mode to perform the next measurement. Figure 10 The paper provides an algorithmic example for this mode, and the system remains in this mode as long as the distance between the object and the system is greater than the threshold distance d3.

[0170] If the distance between the object and the system becomes greater than the distance d2 again, the system re-enters the "boundary" mode.

[0171] Conversely, if the distance between the object and the system becomes less than a threshold distance d3, and if the task requires it, the system will enter "recognition" mode for the next measurement. A series of measurements are then performed so that the shape and properties of the object can be inferred with the highest possible accuracy.

[0172] The task can be defined in advance as instructions.

[0173] When the recognition results are satisfactory, the task continues in a pattern adapted to the next task.

[0174] When a mobile system is equipped with a detection system, the "boundary" mode takes precedence over other modes to prevent potential collisions. More specifically, the detection system includes a watchdog timer, requiring the detection system to revert to boundary mode whenever the watchdog timer's cycle has elapsed.

[0175] According to one embodiment, the detection method can be implemented on a movable system 100 equipped with a detection system in a conductive medium. In this case, the result of the detection method can be used to guide the movement of the movable system 100, for example, to avoid obstacles, or to position the movable system at a certain distance and in an orientation of interest relative to an object present in the wall, interface, or medium.

[0176] Therefore, this task is able to integrate setpoints related to the movement of the movable system 100.

[0177] In one embodiment, the work point configuration box uses the recorded measurements as a basis to determine the next work point.

[0178] In another embodiment, the operating point can be determined by a pre-selected algorithm, independent of the measurement being performed, within the limits of the system's automatic control threshold.

[0179] In one particular embodiment, referred to as a "distributed electronics system," the detection system includes one generator per electrode, and all {generator-electrode-analog measurement device-analog-digital conversion stage} are connected via a bundle of flexible cables to a sealed housing comprising a setpoint generation block and a switching box. Figure 13 As shown. This embodiment makes it possible for only digital signals to be transmitted through the flexible cable, which provides better noise immunity.

[0180] Alternatively, a single generator can be provided to power all electrodes in connected mode. In this case, the generator is located in a sealed housing that includes a setpoint generation block.

[0181] Finally, in one particular embodiment, the detection system includes an interface for communicating with a remote control station, through which an operator can view data originating from the detection process and configure the detection system, particularly specifying tasks to be performed.

[0182] Once the detection system is submerged, a remote operator may be able to remotely modify the task or control the setpoint generation block to perform specific configurations on the detection system.

[0183] Therefore, the multiple possibilities for electrode configuration in the detection system, combined with the automated nature of electrode reconfiguration and potentially remote operator intervention, enable the detection system to provide mapping data of the surrounding space without prior knowledge of that space. This mapping data can correspond to a region of the space surrounding the detection system, which can be statically selected or dynamically changed, either due to the movement of the detection system, such as due to the mobile system 100 equipped with it, or due to previous detection results.

[0184] Drawing data refers to information about a conductive medium having at least one spatial characteristic. Specifically, but not limitingly, it can be the location and possible shape of possible interfaces with other media (liquid, gas, or solid). It can also be the location (spatial coordinates) of a solid object within the medium, and / or its shape and / or the properties of the object, such as its electrical insulation or conductivity.

[0185] For example, switching from boundary mode to location mode is equivalent to shrinking the spatial area covered by the map to focus on the area where objects are detected. It may also change the map scale to obtain more detail in this specific area.

[0186] Reference tag list

[0187] 100: A mobile system equipped with a detection system;

[0188] E i (i is an integer from 1 to n): the i-th electrode of the detection system;

[0189] S 1i (i is an integer from 1 to n): a switch that, if connected, allows selection of the state of electrode i from the transmit and receive states;

[0190] S 2i (i is an integer from 1 to n): Switch, which can select the measurement mode of electrode i from modes U and I;

[0191] S 3i (i is an integer from 1 to n): Switch, which can select the connection state of electrode i from the connected and disconnected connection states.

Claims

1. A method for detection in a conductive medium using a detection system, the detection system comprising: Multiple electrodes E that are in direct electrical contact with the medium i Its status can be selected from the list {transmit, receive, disconnect}. A means for measuring at least one electrical parameter value of each electrode configured in a transmit or receive state, the electrical parameter values ​​being selected from a list {electrical intensity of the electrode, electrical potential of the electrode}. A switching device for configuring each of the electrodes to a state selected from a list {transmit, receive, disconnect}. At least one processor exchanges information with the measuring device and the switching device. The method includes the following steps: a. The processor determines the operating point of the detection system based on the following: Pre-defined setpoints, and / or the previous configuration of the detection system, And / or previous measurement results at at least one of the electrodes transmitted by the measuring device, Determining the operating point of the detection system includes determining the following three parameters: The state of each electrode in the electrode array is selected from three states: transmit, receive, or disconnected. The frequency of at least one sinusoidal component of an electrical signal emitted by at least one of the electrodes configured in the transmitting state. The amplitude of an electrical signal emitted by at least one of the electrodes configured in the emission state; b. The switching device receives information about the operating point of the system determined by the processor, and configures the detection system at the determined operating point; c. A series of measurements are performed by a measuring device, the series of measurements including evaluating at least one electrical parameter value at each electrode configured in a receiving or transmitting state, the measuring device transmitting measurement data to a processor.

2. The detection method according to claim 1, characterized in that, It also includes an additional step, referred to as step d, during which the processor calculates at least one plotting data of the conductive medium based on the measurement data.

3. The detection method according to claim 1 or 2, characterized in that, The steps of the method are repeated at least once in the same order, and a set point is transmitted to the processor so that the repetition of the steps can be controlled by a remote or non-remote operator before the first step a of the detection method, or the repetition of the steps can be controlled by a remote operator during the detection method.

4. The method for detection in a conductive medium according to claim 1, characterized in that, The operating point of the system determined in step a can be selected from the list {"boundary" mode, "positioning" mode, "recognition" mode}, wherein the "boundary" mode enables the maximum detection range in one or more given directions of the medium, the "positioning" mode enables the maximum accuracy of positioning with respect to previously detected objects, and the "recognition" mode enables the best resolution with respect to the shape and / or composition of previously detected objects.

5. The method for detection in a conductive medium according to claim 4, characterized in that, The operating point of the detection system automatically proceeds from step a to the next step: When an object is detected and it is located at a distance less than a threshold distance d2, if it is in "boundary" mode, then it switches from "boundary" mode to "positioning" mode. When an object is detected, and this object is located at a distance less than a threshold distance d3, or has a shape and / or properties corresponding to a set point, if it is in "Location" mode, then it switches from "Location" mode to "Recognition" mode. When an object is detected and the distance to the detected object becomes greater than the threshold distance d2, if it is in "Location" mode, it switches from "Location" mode to "Boundary" mode.

6. The method for detection in a conductive medium according to claim 1, characterized in that, The shape and / or frequency and / or amplitude of the signal emitted by the electrode configured in the emission state at the operating point determined in step a are selected at the end of the frequency scan.

7. The method for detection in a conductive medium according to claim 1, characterized in that, A combination of at least two sinusoidal signals with different frequencies emitted by at least one of the electrodes configured in the emission state for the operating point determined in step a.

8. The method for detection in a conductive medium according to claim 2, characterized in that, If an object is detected in step d, the amplitude and / or shape and / or frequency of the sinusoidal component of the electrical signal emitted by each of the electrodes configured in the emission state for the operating point determined in subsequent step a is determined based on the distance to the detected object.

9. The method for detection in a conductive medium according to claim 2, characterized in that, If an object is detected in step d, the position of the electrode configured to emit in the operating state on the system is determined in subsequent step a based on the shape and / or position of the detected object.

10. The method for detection in a conductive medium according to claim 2, characterized in that, The known references are used to determine at least one piece of plotting data in step d.

11. A computer program comprising, when executed on a computer, program code instructions for performing the steps of the method according to any one of claims 1 to 10.

12. A system for detection in a conductive medium, comprising: Multiple electrodes E that are in direct electrical contact with the medium i Its status can be selected from the list {transmit, receive, disconnect}. A means for measuring at least one electrical parameter value of each electrode configured in a transmitting or receiving state, selected from the list {current intensity through the electrode, electrode potential}. The switching device can configure each of the electrodes to a state selected from the list {transmit, receive, disconnect}. At least one processor exchanges information with the measuring device and the switching device, and is configured to determine the operating point of the detection system based on the following: Pre-defined setpoints, and / or the previous configuration of the system, And / or previous measurement results at at least one of the electrodes transmitted by the measuring device, Determining the operating point of the system includes determining the following three parameters: The state of each electrode in the electrode array is selected from the at least three states: transmit, receive, and disconnect. The frequency of at least one sinusoidal component of an electrical signal emitted by at least one of the transmitting electrodes. The amplitude of an electrical signal emitted by at least one of the electrodes configured in the emission state; Information about the determined operating point is transmitted to the processor of the switching device.

13. A movable system in a conductive medium, equipped with a detection system as described in claim 12, further comprising a control module adapted to control the movement of the movable system based on measurement results obtained by the detection system according to the method described in any one of claims 1 to 10.

14. The movable system in a conductive medium according to claim 13, characterized in that, The electrodes of the detection system are distributed on at least a portion of the surface of the movable system in contact with the medium.

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