Method and device for distinctive capacitive detection and equipment having such a device

Abstract

The invention relates to a method for capacitive detection of nearby objects (102, 104) which may be located in an environment equipped with a capacitive detection device (100), the method comprising a step, referred to as a distinctive detection step, comprising the following operations: - polarizing a first nearby object (102) at a first alternating potential (V1) different from ground potential (M) and from the potential of at least one second nearby object (104) at a first frequency (F1); and - determining a first distinctive signal representing a capacitance, referred to as electrode-object capacitance, seen by the at least one measuring electrode at the first frequency (F1).

Description

Technical Field

[0001] The invention relates to a method for the distinctive capacitive detection of an object located in the environment of an equipment, such as a robot equipped with a capacitive detection device, a capacitive detection device implementing such a method and an equipment, in particular a robot, equipped with such a device.

[0002] The field of the invention is, without limitation, that of human-machine interaction devices, and in particular that of industrial robots or service robots, such as medical or domestic robots, or also collaborative robots, also called “cobots”. Background Art

[0003] Equipment such as robots can be equipped with a device for capacitive detection of nearby objects, which can be stationary objects, mobile objects, living beings, and especially operators.

[0004] Such a capacitive detection device can comprise a capacitive electrode, called a measuring electrode, arranged in the form of a sensitive surface at least partially covering the surface of the equipment or robot, and detection electronics for polarizing the measuring electrode and measuring a signal representative of the capacitance seen by the measuring electrode. Based on the measured signal, the presence and / or contact of a nearby object can be detected.

[0005] However, current capacitance detection devices, especially capacitance detection devices for equipped robots, cannot distinguish between a human operator and any other object. Typically, these devices cannot distinguish between a first nearby object and a second nearby object that may be in the environment of the equipment or robot at the same time or at different times. Therefore, the behavior of the equipment or robot cannot be adjusted or customized when a specific nearby object is detected.

[0006] It is an object of the present invention to overcome these disadvantages.

[0007] Another object of the invention is to propose a distinctive capacitive detection of nearby objects for equipment such as robots.

[0008] The invention also aims to propose a method and a device for capacitive detection of equipment such as a robot, making it possible to distinguish at least one nearby object from at least one other object, said nearby objects being able to be located in the environment of the equipment at the same moment or at different moments.

[0009] The invention also aims to propose a method and a device for capacitive detection of equipment such as a robot, making it possible to distinguish an operator from at least one other nearby object that may be located in the environment of the equipment at the same time as the operator or at a different time. Summary of the invention

[0010] At least one of these objects is achieved by a method for capacitive detection of nearby objects that may be located in an environment of equipment equipped with a capacitive detection device, the capacitive detection device comprising:

[0011] - at least one capacitive electrode, which is called the measuring electrode; and

[0012] - detection electronics for polarizing at least one measuring electrode at an electrical potential and measuring at least one signal representative of the so-called electrode-object capacitance seen by the at least one measuring electrode;

[0013] Characterized in that the method comprises a step of selectively detecting nearby objects (102, 104) called a distinctive detection step, which comprises the following operations:

[0014] - polarizing the first nearby object at a first alternating potential different from ground potential and different from the potential of at least one second nearby object at at least a first frequency; and

[0015] - determining a first distinctive signal representing the capacitance seen by said at least one measuring electrode at said first frequency, referred to as the electrode-object capacitance.

[0016] The method according to the invention therefore envisages polarizing the first nearby object at a first potential different from ground potential and different from the potential of at least one second object, at least at a first frequency. Thus, a capacitive detection operating at (or using) this first frequency can be achieved, which makes it possible to selectively detect one of the objects and therefore distinguish the first object from the second object, regardless of the polarization potential of the measuring electrodes.

[0017] For example, if the measuring electrode is polarized at a first potential, a first object will be electrically invisible to the capacitive detection device equipped with the equipment, since it will not generate a potential difference between the first object and the measuring electrode. When a second object is polarized at a first frequency, at a potential different from the first potential, a capacitance seen by the measuring electrode at said first frequency is established between the second object and the measuring electrode: the second object will therefore be able to be seen differently from the first object. In this case, the measuring electrode will be used to perform a "self-capacitance" detection, and the first distinctive signal will only indicate the presence or absence of the second object.

[0018] In contrast, if the measuring electrode is polarized at least at the first frequency at a potential different from the first potential, the measuring electrode is used as a receiving electrode and the first object is used as a transmitting electrode, the measuring electrode selectively detecting the first object at the first frequency. In this case, the measuring electrode will be used so as to perform a "transmitting" detection at the first frequency, and the first distinctive signal will only indicate the presence or absence of the first object.

[0019] The method according to the invention thus proposes capacitive detection, which makes it possible to distinguish at least one nearby object from at least one other object that may be in the environment of the equipment at the same moment or at a different moment. The method according to the invention thus makes it possible to adapt or even customize the behavior of the equipment according to the detected object.

[0020] A "nearby object" is any fixed or mobile object, whether alive or not, that may be located in the environment of the equipment and independent of said equipment. Such a nearby object does not constitute a part of the equipment and does not participate in the operation of said equipment or in the operation of a capacitive detection device equipped with said equipment. For example, it may be an object located in the environment of the equipment, such as an operator or person, a conveyor belt, a table or work area, a truck, etc.

[0021] In the context of the present invention, "equipment" can refer to any type of equipment, system, apparatus, or sub-part of an apparatus. For example, it can refer to:

[0022] - Panels or control interfaces, dashboards, cockpits of vehicles;

[0023] - appliances or industrial machines, such as those used for processing, treatment or packaging;

[0024] - Mobile systems, such as trucks, vehicles, autonomous vehicles;

[0025] - Robots in various forms, such as robotized systems, mobile robots, wheeled or rail vehicles, such as trucks equipped with arms or manipulator systems, or robots of the humanoid, gynoid or android type, optionally provided with moving parts such as limbs.

[0026] In particular, equipment can be mobile when it is capable of moving or when it comprises moving parts.

[0027] In the present application, when two alternating potentials each include the same alternating component at a given frequency, the two alternating potentials are the same at the frequency. Therefore, at least one of the two potentials that are the same at the given frequency can also include a DC component and / or an alternating component having a frequency different from the given frequency. Similarly, when two alternating potentials do not include the same alternating component at a given frequency, the two alternating potentials are different at the frequency.

[0028] Two alternating components are identical when they have the same frequency, the same amplitude (e.g., plus or minus a few percentage points), and the same phase (e.g., plus or minus a few degrees). Two alternating components are not identical when they are different. They can be, for example, alternating components of different frequencies, or alternating components of the same frequency but out of phase, such as in phase quadrature.

[0029] The alternating potential realized in the context of the invention can of course be of any shape (sinusoidal, square, triangular, etc.).

[0030] In the present application, the term "ground potential" or "universal ground potential" refers to a reference potential of an electronic device, equipment or its environment, which can be, for example, the potential of a universal ground of the electronic device. The ground potential can correspond to the earth potential or another potential connected or not connected to the earth potential.

[0031] Generally, in this application, electric potential is defined relative to a common reference, which can be, for example, the ground of an electronic device. In this case, the ground potential corresponds to, for example, a zero value (0 V).

[0032] Furthermore, it should be noted that, in general, objects that are not in direct electrical contact with a particular electrical potential (electrically floating objects) tend to become polarized through capacitive coupling at the potential of other objects present in their environment, such as the ground or electrodes, if the surface area of ​​overlap between these objects and those objects (or electrodes) of the environment is large enough.

[0033] Without limitation, determining the first distinctive signal at the first frequency can be performed, for example, by realizing a synchronous demodulation of the measurement signal with a carrier signal at the first frequency, which carrier signal is preferably identical to the first potential, or at least has the same phase.

[0034] With this synchronous demodulation, selective detection of a second nearby object polarized at a potential different from the first alternating potential in one of the following ways is possible:

[0035] - the potential does not include a component at the first frequency;

[0036] The potential comprises a component at the first frequency, but is only in phase quadrature with the first potential at the first frequency. In this case, synchronous demodulation can in fact be used to distinguish or select the in-phase and quadrature components of the global measurement signal.

[0037] Determining the first distinctive signal at the first frequency can also be performed with an asynchronous demodulator or envelope detection, for example by rectifying a bandpass filtered measurement signal around the first frequency and subsequently lowpass filtering it.

[0038] In the case of such envelope detection, selective detection can be performed using a second nearby object polarized at a potential different from the first alternating potential because this potential does not include a component at the first frequency.

[0039] It should be noted that in all cases, for the selective detection step, the potential of the second object must be different from the first alternating potential in the sense that it does not comprise components indistinguishable from the first alternating potential for the detection electronics utilized.

[0040] The method according to the invention can comprise, during the distinctive detection step, polarizing the at least one second object at ground potential.

[0041] Alternatively or additionally, the method according to the invention can comprise, during the step of distinctive detection, polarizing at least one second object at a second alternating potential at a second frequency different from the first frequency.

[0042] In this case, the individual detection of this second object can be performed in isolation from the other objects by determining a second distinctive signal, which is representative of the electrode-object capacitance seen by the at least one measuring electrode at this second frequency. In fact, in this case, the second distinctive signal will only represent the presence or absence of the second object, regardless of the presence or absence of the first object (assuming, of course, that the first alternating potential does not include a component that is not distinguishable at the second frequency).

[0043] Without limitation, determining the second distinctive signal at the second frequency can be performed, for example, by synchronous demodulation of the measurement signal using a carrier signal at the second frequency or a carrier signal identical to the second potential at the second frequency.

[0044] Alternatively or additionally, the method according to the invention can comprise, during the distinctive detection step, polarizing at least one second object at the first frequency, at a potential which is identical to the first alternating potential frequency and orthogonal to the first alternating potential.

[0045] Potentials are said to be in quadrature, or orthogonal with respect to the scalar product, when the sum of the scalar product of the potentials, or the products of their successive time values, is zero (at least ± the noise level).

[0046] These potentials can of course be of any waveform (sinusoidal, square, triangle, etc.).

[0047] Examples of orthogonal potentials include, for example, potentials having different frequencies (or fundamental frequencies) that are not multiples of each other, and potentials of the same frequency (or the same fundamental frequency) that are orthogonal in phase.

[0048] Thus, in this case, each of the first and second objects is polarized at a potential comprising a component at the first frequency. However, these components are orthogonal to one another so that, according to the definition given above, they can be distinguished for capacitive detection. The detection of each of the first and second objects can then be performed separately during a distinctive detection step.

[0049] The potentials or their orthogonal components can be in phase quadrature. As described above, capacitance detection can utilize synchronous demodulation, wherein at least one carrier signal is in phase with the first alternating potential to detect the corresponding component, and optionally the carrier signal is in quadrature with the first alternating potential to detect the quadrature component.

[0050] When the step of differential detection comprises separate or selective detection of a first object and separate or selective detection of a second object, these separate detections can:

[0051] - simultaneously or sequentially based on the same measurement signal; or

[0052] - Executed sequentially based on two sequentially measured signals.

[0053] According to an embodiment, during the differential detection step, at least one measuring electrode can be polarized at ground potential.

[0054] In this case, capacitive detection is transmission detection using one or more measuring electrodes as receiving electrodes and the object(s) as transmitting electrode(s).

[0055] In this embodiment, the individual detection of the first object and the individual detection of at least one second object may be performed simultaneously or sequentially, as described above.

[0056] Alternatively, at least one measuring electrode can be polarized at a third alternating potential.

[0057] In this case, the potential of the at least one measuring electrode therefore differs from ground potential and comprises at least one alternating component at at least one frequency.

[0058] According to a non-limiting embodiment of the method of the invention, during the differential detection step, the third polarization potential can:

[0059] - is different from the first polarization potential at the first frequency, and

[0060] - where applicable, different from the second polarization potential at the second frequency.

[0061] In other words, as described above, the third polarization potential does not comprise any components which are indistinguishable from the first and / or second alternating potential for the detection electronics utilized.

[0062] For example, in case of synchronous demodulation, a third quadrature potential in terms of scalar product at the first operating potential, in particular at the first operating frequency and / or at a different frequency can be used. In case of envelope detection, a third potential with a frequency different from the first operating frequency can be used.

[0063] The same reasoning applies to the second operating potential at the second frequency.

[0064] In this case, during the distinctive detection step, at least one measuring electrode is used as a receiving electrode in the context of a transmission capacitance detection with the following detections (simultaneously or sequentially):

[0065] - performing a separate detection of the first object at the first frequency, and

[0066] - Where applicable, performing separate detection of the second object at a second frequency.

[0067] For example, the third potential may not include an alternating component at the first frequency and, where applicable, may not include an alternating component at the second frequency.

[0068] Alternatively, the third potential can be the same as the first potential at the first frequency, or the same as the second polarization potential at the second frequency.

[0069] For example, the third potential can be identical to the first potential at the first frequency.In this case, the first object becomes invisible and the second object generates a capacitance seen by the measuring electrode in the self-detection mode at the first frequency.

[0070] Alternatively, the third potential can be the same as the second potential at the second frequency. In this case, the second object becomes invisible and the first object can be detected in the transmission mode at the first frequency.

[0071] The method according to the present invention can also include a step of detecting nearby objects, called a co-detection step, which includes the following operations:

[0072] - polarizing at least one measuring electrode at least at a frequency called operating frequency, at an alternating potential called operating potential, which is different from ground potential and from the potential of the first and second nearby objects; and

[0073] - determining a common signal which represents the capacitance seen by at least one measuring electrode at said operating frequency, referred to as the electrode-object capacitance.

[0074] Thus, the common signal represents the capacitance of one or more objects that cannot be distinguished due to the presence of the first object, or due to the presence of the second object, or due to the presence of both objects. In other words, the common signal represents the presence or absence of at least one object without being able to distinguish the objects.

[0075] According to a specific non-limiting embodiment, during the co-detection step:

[0076] - the operating frequency can be identical to the first frequency and at this frequency the operating potential can be identical to the first polarization potential of the first object during the differential detection step, or

[0077] - where applicable, the operating frequency can be identical to the second frequency and at this frequency the operating potential can be identical to the second polarization potential of the second object;

[0078] A distinctive detection step and a common detection step are sequentially performed, and the method includes the step of changing the potential of the first object or the potential of the second object between the detection steps.

[0079] In this case, the distinctive detection step and the common detection step are performed sequentially.

[0080] Furthermore, the distinctive detection step comprises a measurement of the electrical signal, from which measurement a first distinctive detection signal is determined, and the common detection step comprises a further measurement of the electrical signal, from which further measurement a common detection signal is determined.

[0081] According to another embodiment, the working potential used during the common detection step can:

[0082] - a polarization potential of the object at the first frequency that is different from that used during the differential detection step; and

[0083] - where applicable, different from the second potential at the second frequency.

[0084] In this case, the distinctive detection step and the common detection step can be performed simultaneously, so that the common signal and the distinctive signal(s) are determined from the same measurement signal.Thus, the method according to the invention enables a faster detection from the same measurement signal.

[0085] Alternatively, in this embodiment, the distinctive detection step and the common detection step can also be performed sequentially according to different measurement signals.

[0086] According to a first example of this embodiment, the operating frequency can be a first frequency, but at this frequency the operating potential can be orthogonal to each polarization potential used to polarize the object at the first frequency.

[0087] According to another example of this embodiment, the operating frequency can be the second frequency, but at this frequency the operating potential can be orthogonal to the second potential and more generally to each polarization potential used to polarize the object at this second frequency.

[0088] According to another example, the working potential used during the common detection step can have a frequency different from the first frequency and, where applicable, can have a frequency different from the second frequency.

[0089] The method according to the invention therefore envisages polarizing at least a first object at a first frequency, at a potential different from ground potential.

[0090] In order to do this, at least one nearby object can be polarized in wired connection to a source supplying power to the capacitive detection device used in the method according to the invention.

[0091] Alternatively or additionally, at least one nearby object can be polarized by a power source independent of powering the detection device.

[0092] In this case, the method according to the invention can comprise exchanging wireless signals between said sources for:

[0093] - synchronizing the sources with each other; or

[0094] - Acquiring the frequency and / or phase of the polarization signal of the at least one nearby object.

[0095] Such wireless signals can be exchanged by any wireless connection using any type of communication protocol.

[0096] For example, such wireless signals can be exchanged via Bluetooth, a WiFi connection or more generally via any radio connection.

[0097] Advantageously, at least one nearby object can be the body or a body part of a human operator.

[0098] Therefore, the presence or absence of the operator can be detected independently of the presence or absence of another object.

[0099] Thus, it is possible to envisage at the equipment level a specific behavior in the case of detecting an operator, and a different behavior in the case of detecting another object. In particular, a specific behavior can be adopted that optimizes operator safety, because the operator can be detected by distinguishing the operator from another, in particular from any other nearby object.

[0100] According to one embodiment, the first object can be at least a part of a body of a human operator, and in particular a hand or an arm of said operator.

[0101] The human operator or a part of the human operator's body can be polarized via one or more electrical contacts, the one or more electrical contacts being equipped with at least:

[0102] - a wrist strap worn by the operator,

[0103] - a piece of clothing worn by the operator,

[0104] - shoes worn by the operator,

[0105] -etc.

[0106] Alternatively, the first object can also be a work area facing equipment such as a table, a workbench, a belt conveyor, and the second object can be at least a part of the body of a human operator.

[0107] The method according to the present invention can also include the following steps:

[0108] - in case a first object is detected during the distinctive detection step, triggering at least one first command previously associated with the first object; and

[0109] - In case a second object is detected during the distinctive detection step, at least one second command previously associated with the second object is triggered, the second command being different from the first command.

[0110] For example, when one of the objects is an operator, the command associated therewith can be an emergency procedure or the stopping of the equipment when the latter is mobile or comprises moving parts (such as a robot).

[0111] Still according to a non-limiting example, when one of the objects is an object other than an operator, the command associated therewith can be a slowing down or a change in the trajectory of the mobile equipment or a mobile part of the equipment.

[0112] Of course, the method according to the invention enables selective detection of multiple first objects in the presence of one or more second objects. Thus, for example, different first alternating potentials can be applied to different first nearby objects, respectively, and selectively and individually detected according to the invention.

[0113] Thus, for example, different operators can be polarized at different first frequencies and identified. The individually detected first objects can also include operators and other elements of the environment, such as mobile elements, trucks, workbenches or the like.

[0114] Furthermore, the second object can represent any element of the environment of the equipment or robot (the ground, a conveyor belt, an operator, etc.) which is, for example, at earth potential or ground potential.

[0115] According to another aspect of the present invention, a capacitance detection device for equipment is provided, comprising:

[0116] - at least one capacitive electrode, which is called the measuring electrode; and

[0117] - detection electronics for polarizing at least one measuring electrode and measuring at least one signal representative of the capacitance seen by said at least one measuring electrode, called electrode-object capacitance; and

[0118] - means for polarizing at least one nearby object;

[0119] The capacitance detection device is arranged to implement all steps of the method according to the invention.

[0120] In particular, the capacitance detection electronics can be configured to implement each of the steps or operations described above with reference to the method according to the present invention, alone or in combination, and for the sake of brevity, they are not repeated here.

[0121] The means for polarizing at least one nearby object can include at least one electrical contact that transmits a polarization potential from a power source to the object.

[0122] When the nearby object is a human body or a part of a human body, the polarization means can include at least one electrical contact placed at least in:

[0123] - a wrist strap worn by the operator,

[0124] - clothing worn by the operator,

[0125] - shoes worn by the operator,

[0126] -etc.

[0127] The arrangement according to the invention can comprise a common power source for powering the detection electronics and polarizing at least one nearby object.

[0128] In this case, the nearby objects are connected to the detection electronics in a wired manner.

[0129] Alternatively or additionally, the device according to the invention can comprise:

[0130] - a first power source for polarizing the first object; and

[0131] - a second source for powering the detection electronics independently of said first source.

[0132] In this case, the first power source can communicate with the detection electronics by wire or wirelessly to send and / or receive synchronization signals of the polarization potential it provides to nearby objects.

[0133] On one side of the nearby object, the swapped signal can be used to provide the correct polarization of the nearby object.

[0134] On the side of the detection electronics, the exchanged signal can be used to determine the distinctive signal and, more specifically, used as the signal measured by the detection electronics during the distinctive detection phase or to generate a carrier for synchronously demodulating this signal.

[0135] According to an alternative embodiment, the device according to the invention can comprise a single power source for sequentially polarizing:

[0136] - at least one nearby object, and

[0137] - measuring electrodes;

[0138] The apparatus further comprises means for sequentially connecting and disconnecting the source to and from the nearby object and the measuring electrodes.

[0139] The connection / disconnection means can comprise a controlled switch.

[0140] It is possible to switch between a distinctive detection step, during which the source polarizes the nearby objects, and a common detection step, during which the source polarizes the measuring electrodes.

[0141] The detection device can also comprise at least one guard electrode for electrically protecting the at least one measuring electrode.

[0142] In this case, at least one guard electrode is polarized at the same potential as the measuring electrode or, where applicable, at the same potential at the detection frequency as the measuring electrode.

[0143] The detection electronics can be manufactured using analog or digital components or by a combination of analog and digital components.

[0144] According to an embodiment, the capacitance detection electronics can include a measurement stage including an operational amplifier (OA) or a circuit producing an operational amplifier, the measurement stage acting as a transimpedance or charge amplifier, wherein:

[0145] - a first input, for example an inverting input, connected to one or more measuring electrodes directly or via, for example, a polling device;

[0146] A second input, for example a non-inverting input, is connected to the polarization potential of the measuring electrode (and, if applicable, the guard electrode).

[0147] The output of the OA is looped over the first input via an impedance, in particular via a capacitor.

[0148] In this configuration, the output of the OA provides a voltage V S , whose magnitude is proportional to the electrode-object capacitance between at least one measuring electrode and the object.

[0149] The detection electronics can also comprise an oscillator which provides an alternating potential which polarizes the measuring electrode and, if applicable, the at least one guard electrode.

[0150] The polarization potential can comprise a sinusoidal or square wave signal, or any other waveform. The detection frequency can correspond to the fundamental frequency of the waveform.

[0151] The detection electronics can include at least one analysis stage for determining the voltage V provided by the measurement stage. S The detection signal is determined at a detection frequency, ie, a first frequency, or a second frequency, or an operating frequency.

[0152] This analysis stage can include a demodulator (synchronous or asynchronous) at the detection frequency, or an amplitude detector, a calculation module, etc.

[0153] The detection electronics can comprise a single analysis stage which in turn is used to determine each detection signal, ie the first distinctive detection signal, where applicable the second distinctive detection signal, and the common detection signal.

[0154] Alternatively, the detection electronics can comprise several analysis stages, each dedicated to determining the detection signal, namely:

[0155] - a first analysis stage for determining a first distinctive detection signal,

[0156] - where applicable, a second analysis stage for determining a second distinctive detection signal, and

[0157] - A third analysis stage, which serves to determine the common detection signal.

[0158] The or each analysis stage can be an analog or digital step, a physical level or a software level. Furthermore, the analysis stages can be arranged in series or in parallel.

[0159] According to another aspect of the same invention, a device is proposed which is provided with a capacitance detection device according to the invention.

[0160] According to a non-limiting embodiment, the equipment can be of robotic type, or comprise any robotized system.

[0161] As mentioned above, it can in particular have the form of a robot arm or comprise a robot arm.

[0162] The robot can also be or comprise, for example, a mobile robot, a wheeled or rail-mounted vehicle, such as a truck equipped with an arm or a handling system, or a robot of the animatronic, gnu or android type, optionally provided with moving parts such as limbs. BRIEF DESCRIPTION OF THE DRAWINGS

[0163] Other advantages and features will become apparent by examining the detailed description of non-limiting examples and from the accompanying drawings, in which:

[0164] - Figure 1 is a schematic diagram of a non-limiting embodiment of a capacitance detection device that can be used in the present invention;

[0165] - Figure 2a is a schematic diagram of one example of a step in which a distinctive capacitance detection step may be performed;

[0166] - Figure 2b is a schematic diagram of an example of a common capacitance detection step that can be performed;

[0167] - Figure 3a is a schematic diagram of one example of a step in which a distinctive capacitance detection step may be performed;

[0168] - Figure 3b is a schematic diagram of another example in which a distinctive capacitance detection step may be performed;

[0169] - Figure 4 is a schematic diagram of another example in which the distinctive capacitance detection step and the common detection step may be performed;

[0170] - Figure 5a and Figure 5b is a schematic diagram of two configurations of one example in which a single power supply may be used to perform both the distinctive capacitive detection step and the common detection step;

[0171] - Figure 6 is a schematic diagram of another example in which the distinctive capacitance detection step may be performed; and

[0172] - Figure 7a and Figure 7b is a schematic diagram of two configurations of another example in which a single power supply may be used to perform both the distinctive capacitive detection step and the common detection step. DETAILED DESCRIPTION

[0173] It is understood that the embodiments described below are by no means limiting. In particular, it is conceivable that variations of the invention include only a selection of the features described below (isolated from the other features described), as long as the selection of features is sufficient to confer a technical advantage or to distinguish the invention from the prior art. The selection includes at least one, preferably functional, feature without structural details, or a feature with only a portion of a structural detail, as long as the portion is sufficient to confer a technical advantage or to distinguish the invention from the prior art.

[0174] In particular, all described variants and all exemplary embodiments can be combined, provided that such a combination is not objectionable from a technical point of view.

[0175] In the figures, elements common to several figures have the same reference numerals.

[0176] Figure 1 is a schematic diagram of a non-limiting embodiment of a capacitance detection device that can be implemented in the context of the present invention.

[0177] Figure 1 The device 100 shown in FIG. 1 can be produced in analog or digital form, or a combination of analog and digital components.

[0178] Figure 1 Also shown are a first nearby object 102 and a second nearby object 104 which may be detected by the device 100 and which do not form part of equipment (eg a robot) with which the detection device 100 is equipped.

[0179] In order to detect nearby objects 102-104, the capacitance detection device 100 includes several capacitance electrodes 1061-106 n , referred to as measuring electrodes, so that one or more measuring electrodes 1061-106 formed on one side can be measured n The value of the charge, in particular the voltage, between one or more objects 102 and 104 on the other hand represents the capacitance referred to as the electrode-object capacitance. i Can be used to represent a measuring electrode.

[0180] The device 100 also optionally comprises at least one electrode 108, called guard electrode, for electrical protection of the measuring electrode 106. To this end, the guard electrode 108 is set to the same potential as the measuring electrode 106, at least at the detection frequency of the electronics.

[0181] The detection device 100 also includes detection electronics 110 for:

[0182] - polarizing at least one measuring electrode 106 at a potential, which can be ground potential or a potential different from ground potential, for example an alternating potential, and

[0183] - measuring at least one signal representative of a capacitance known as electrode-object capacitance seen by the at least one measuring electrode 106 .

[0184] To this end, the detection electronics 110 comprises a measuring stage 112 .

[0185] The measurement stage 112 includes a current or charge amplifier represented by an operational amplifier (OA) 114 , and a feedback capacitor 116 looping the output of the OA 114 at the inverting “−” input of the OA 114 .

[0186] Furthermore, in the example shown, the non-inverting “+” input of OA 112 receives the polarization potentials of the measuring electrode 106 and the guard electrode 108, and the inverting “-” input of OA 114 is arranged to be connected to each measuring electrode 106 via the polling device 118. i , so as to poll the measuring electrodes 106 individually in sequence.

[0187] Of course, the polling device 118 is optional and can be, for example, a switch.

[0188] Under these conditions, the charge amplifier, in particular OA 114, provides a voltage V at the detection frequency at its output. S , whose magnitude is equal to the coupling capacitance C between one or more measuring electrodes 106 connected at the “-” input of the charge amplifier and one or more objects close to or in contact with the measuring electrodes 106, called the electrode-object capacitance. eo In the example shown, the voltage V S It is measured relative to the ground potential indicated by M in the reference numeral.

[0189] In general, the measurement stage 112 can be analog and / or digital (microprocessor) and comprises all necessary means for filtering, conversion, processing, etc. The measurement stage 112 can also comprise components other than those described.

[0190] The detection electronics 100 can further comprise an analysis stage 120 which is configured to analyze the signal V S And the capacitance detection signal is derived therefrom.

[0191] The analysis stage 120 can include:

[0192] a demodulator (synchronous or asynchronous) for demodulating the signal provided by the measurement stage 112 at the detection frequency,

[0193] - an amplitude detector for measuring the amplitude of the signal provided by the demodulator; and

[0194] - A computing module for providing a signal regarding the presence and / or contact of one or more nearby objects.

[0195] As previously mentioned, the demodulator can thus comprise a synchronous demodulator. In this case, the measurement signal originating from the measurement stage 112 is optionally bandpass filtered, then multiplied by a carrier signal at the detection frequency, preferably in phase with the measurement signal, and then lowpass filtered to obtain the amplitude signal.

[0196] The demodulator can also comprise an asynchronous demodulator or envelope detection, wherein the bandpass filtered measurement signal is rectified around the detection frequency and subsequently low-pass filtered, for example.

[0197] The calculation module can be configured to determine a distance or a distance information item and / or a contact or a contact information item between at least one measuring electrode 106 and at least one object. For example, the calculation module can include a microcontroller or an FPGA, or can be manufactured in the form of a microcontroller or an FPGA. The calculation module can also provide other information items, such as triggering an alarm or a safety procedure when, for example, the measured distance is less than a predetermined distance threshold.

[0198] exist Figure 1 In , only one analysis stage is shown. Of course, the detection electronics can comprise several analysis stages used simultaneously or sequentially, for the same detection frequency or for different detection frequencies.

[0199] In general, the analysis stage 120 can be analog and / or digital (microprocessor) and comprises all necessary means for filtering, conversion, processing, etc. The analysis stage 120 can also comprise components other than those described.

[0200] The detection electronics 110 or at least the sensitive part thereof with the charge amplifier can be referenced to (or supplied with a referenced power supply to) the same potential as the guard electrode to minimize parasitic capacitances, in particular when this potential varies alternately and / or is different from ground potential M. The detection electronics 100 can also be referenced to ground potential M more conventionally.

[0201] Figure 2a and Figure 2b are schematic diagrams of two configurations of general examples for performing the distinctive capacitance detection step and the common capacitance detection step.

[0202] Figure 2a shows a configuration for performing a distinctive capacitance detection step, while Figure 2b A configuration is shown for performing a common detection step.

[0203] exist Figure 2aand Figure 2b In the example 200 shown:

[0204] - setting the measuring electrode 106 at the potential V0,

[0205] - setting the first nearby object 102 to an alternating potential V1 at a frequency F1, and

[0206] - The second nearby object 104 is set at the potential V2.

[0207] Reference Figure 2a , a step of distinctive detection of one of the nearby objects can be performed at a non-zero frequency F1, and it is provided that the potentials V1 and V2 are different at the frequency F1, and the potential V1 is different from the ground potential M.

[0208] According to the first case, if the potentials V1 and V0 are the same or substantially the same at the frequency F1, then V1 and V0 have (substantially) the same phase and the same amplitude at the frequency F1. In this case, the first object 102 will be at the same potential as the measuring electrode at the frequency F1. Capacitive detection at the frequency F1 will only detect the object 104, because the object 102 is not electrically visible to the measuring electrode 106, because it is at the same potential. Therefore, the capacitive detection will be self-capacitive capacitance detection.

[0209] According to the second case, if the potentials V1 and V0 are different at the frequency F1, the capacitive detection at the frequency F1 will only detect the object 102, provided of course that the potentials V0 and V2 do not generate (at least significant) components that can be measured by the demodulator at the frequency F1, i.e., in particular, there is no component at the frequency F1, or, in the case of using only a synchronous detector, there is no component in phase with the potential V1 at the frequency F1. The capacitive detection will then be a transmission capacitive detection using the object 102 as a transmitting electrode and the measuring electrode 106 as a receiving electrode. In this case, the potential V0 can be equal to or different from the ground potential M. In addition, the potential V2 can be equal to or different from the ground potential M and / or equal to or different from the potential V0.

[0210] According to the third case, if the potential V1 is different from V0 at the frequency F1, and the potential V2 as the alternating potential is also different from V0 at the frequency F2, the capacitance detection at the frequency F1 will detect only the object 102. In addition, it is possible to perform capacitance detection at the frequency F2, which will detect only the object 104. Then, the capacitance detection will be a transmission capacitance detection using the object 102 as the transmitting electrode and the measuring electrode 106 as the receiving electrode. This is possible in the case of using a synchronous or asynchronous demodulator and different frequencies F1 and F2. This is also possible in the case of using a synchronous demodulator operating in phase and orthogonally and using a potential V2 at the frequency F1 (or F2) that is the same frequency as V1 but orthogonal in phase.

[0211] Reference Figure 2b By applying an alternating potential V0 of frequency F0 to the measuring electrode 106, all objects 102 and 104 can be detected indiscriminately by means of demodulation at frequency F0, as long as the potentials V0 and V1, V0 and V2 are different at F0. As described above, these conditions are met if the potentials V1 and V2 do not generate (at least significant) components that can be measured by the demodulator at frequency F0, i.e., in particular, there are no components at frequency F0 or, in the case of using only a synchronous detector, there are no components at frequency F0 that are in phase with the potential V0.

[0212] In particular, for the common detection step, the potentials V1 and V2 can be made equal to or substantially equal to the ground potential M.

[0213] The frequency F0 can be different from the frequencies of V1 and V2, which allows synchronous or asynchronous demodulation.

[0214] Alternatively, using synchronous demodulation, V0 can have the same frequency as V1 , V2 , respectively, but be in phase quadrature with V1 , V2 , respectively.

[0215] From the above, it can be inferred that when the potentials V1, V2 and V0 are all different, it is possible to execute:

[0216] - on the one hand, a step of distinctively detecting nearby objects, detecting object 102 individually using demodulation at F1 and detecting object 104 individually using demodulation at F2; and

[0217] - On the other hand, the step of jointly detecting objects indiscriminately detects all objects present using demodulation at F0.

[0218] Furthermore, the steps can be performed simultaneously or sequentially.

[0219] In case of synchronous or asynchronous demodulation, V0, V1 and V2 can have different frequencies.

[0220] Alternatively, in case of synchronous demodulation, at least one of the potentials V0, V1 and V2 can have the same frequency but in phase quadrature as at least one other of the potentials V0, V1 and V2.

[0221] Now refer to Figures 3a to 5b In these figures, without limitation, the first nearby object 102 is considered to be the operator's hand, and the second nearby object 104 is any other object that can be found in the environment of the equipment, in the illustrated case a robot, such as a table, a support, a workbench, another robot, etc.

[0222] Figure 3a is a schematic diagram of an example of an embodiment of steps for performing distinctive capacitance detection.

[0223] Specifically, Figure 3a The example 300 shown in makes it possible to perform distinctive capacitive detection of a hand 102 (which corresponds to a first nearby object 102).

[0224] To this end, the hand 102 is polarized at a potential V1 having a frequency F1 , which is delivered by the power supply 302 and which is different from the ground potential M.

[0225] The second object 104 and the capacitive electrode 106 are polarized at a ground potential M.

[0226] This example 300 makes it possible to perform a differential capacitive detection step to detect the presence or absence of the hand 102 at the frequency F1. The detection performed is a transmission detection using the hand 102 as a transmitting electrode and the measuring electrodes 106 as receiving electrodes.

[0227] However, this example 300 cannot perform a common capacitance detection step, ie, a step of detecting either of the objects 102 and 104 indiscriminately.

[0228] Figure 3b is a schematic diagram of an example of an embodiment of steps for performing distinctive capacitance detection.

[0229] In particular, Figure 3b The example 310 shown in FIG. 3 enables a distinctive capacitive detection of the hand 102 (which corresponds to the first proximate object 102 ) and a distinctive detection of the second object 104 to be performed.

[0230] For this reason, Figure 3a As shown, the hand 102 is polarized at a potential V1 having a frequency F1, which is delivered by the power supply 302 and is different from the ground potential M.

[0231] The capacitor electrode 106 is polarized at ground potential, as shown in FIG. Figure 3a shown.

[0232] As for the second object 104 , it is polarized at a potential V2 having a frequency F2 , which is delivered by the power source 312 and is different from the ground potential M and the potential V1 .

[0233] This example 310 makes it possible to perform a distinctive capacitive detection step to detect the presence or absence of the hand 102 at the frequency F1. The detection performed at the frequency F1 is a transmission detection using the hand 102 as a transmitting electrode and the measuring electrode 106 as a receiving electrode.

[0234] Furthermore, this example 310 makes it possible to perform a distinctive capacitive detection step to detect the presence or absence of the second object 104 at frequency F2. The detection performed at frequency F2 is a transmission detection using the second object 104 as a transmitting electrode and the measuring electrode 106 as a receiving electrode.

[0235] exist Figure 3b In the example 310 described in , the same analysis stage 120 is used for both the distinctive capacitance detection at frequency F1 and the distinctive capacitance detection at frequency F2. Alternatively, two analysis stages may be used, one for the distinctive capacitance detection at F1 and another for the distinctive capacitance detection at F2.

[0236] Furthermore, the distinctive capacitance detection at F1 and F2 can be performed simultaneously or sequentially.

[0237] In order to perform a differentiated detection with a synchronous or asynchronous demodulator, for example different frequencies F2 and F1 can be used. For a synchronous demodulator, it is also possible to use potentials V1 and V2 with the same frequency and in phase quadrature.

[0238] It should be noted that this example 310 also makes it possible to perform a common capacitance detection step, that is, a step of indiscriminately detecting any one of the objects 102 and 104 by applying the same or substantially the same potentials V1 and V2 at the frequency F1 (or F2). In this case, by changing the configuration of at least one power supply 302, 312, the step of distinguishing detection and the step of common detection are performed sequentially.

[0239] Figure 4 is a schematic diagram of an example of an embodiment for performing a distinctive capacitance detection step and a common detection step.

[0240] In particular, Figure 4 The example 400 shown in makes it possible to perform distinctive capacitive detection of the hand 102 but also to perform common detection of all nearby objects indiscriminately.

[0241] To this end, the hand 102 (which corresponds to the first nearby object) is polarized at a potential V1 having a frequency F1 , which is delivered by the power source 302 and is different from the ground potential M.

[0242] The second object 104 is polarized at ground potential M.

[0243] As for the measuring electrode 106 , it is polarized at a potential V0 with a frequency F0 , which is delivered by the source 402 and which is different from the ground potential M and from the potential V1 .

[0244] This example 400 makes it possible to perform a distinctive capacitive detection step to detect the presence or absence of the hand 102 at the frequency F1. The detection performed at the frequency F1 is a transmission detection using the hand as a transmitting electrode and the measuring electrodes 106 as receiving electrodes.

[0245] Furthermore, this example 400 enables a common detection step to be performed at F0, so that the presence or absence of any nearby object can be detected indiscriminately. The detection performed at frequency F0 is a self-capacitance detection, because any nearby object, in particular objects 102 and 104, produces a capacitance seen by measurement electrode 106 at frequency F0.

[0246] As mentioned above, different frequencies F0 and F1 may be used. Alternatively, for a synchronous demodulator, potentials V0 and V1 in phase quadrature with the same frequency (F0=F1) may be used.

[0247] exist Figure 4 In the example described in , the same analysis stage 120 is used for distinctive capacitance detection at F1 and for common capacitance detection at F0. Alternatively, two analysis stages may be used, one for distinctive capacitance detection at F1 and another for common capacitance detection at F0.

[0248] Furthermore, in the example 400 , the distinctive capacitance detection step and the common capacitance detection step can be performed simultaneously based on a single measurement signal provided by the measuring step 112 .

[0249] exist Figure 4 In the example described in , at least two power supplies are used to perform the distinctive capacitance detection step and the common capacitance detection step.

[0250] It is also possible to perform these two capacitance detection steps sequentially using a single power supply.

[0251] Figure 5a and Figure 5b is a schematic diagram of two configurations of an example that enables the distinctive capacitance detection step and the common detection step to be performed using a single power supply.

[0252] In particular, Figure 5a represents a configuration that enables distinctive capacitive detection of the hand 102 alone to be performed, and Figure 5b102 represents a configuration that enables common capacitance detection of any object including the hand 102 to be performed indiscriminately.

[0253] exist Figure 5a and Figure 5b In the example shown, a single power source is used, namely the power source 302 which delivers an alternating potential V1 at a frequency F1.

[0254] The first switch 502 is used to selectively associate the hand 102 with the ground potential M or the potential V1 delivered by the power source 302 .

[0255] The second switch 504 is used to selectively associate the measuring electrode 106 with the ground potential M or with the potential V1 delivered by the source 302 .

[0256] Regardless of the configuration, the second object 104 is polarized at ground potential M.

[0257] exist Figure 5a In the configuration shown, the hand is connected to the power supply 302 via the switch 502: the hand is therefore polarized at the potential V1. At the same time, the measuring electrode 106 is connected to the ground potential M via the switch 504: the measuring electrode 106 is therefore polarized at the ground potential M. This configuration makes it possible to perform a discriminative capacitive detection step to detect the presence or absence of the hand 102 alone at the frequency F1. The detection performed at the frequency F1 is a transmission detection using the hand 102 as a transmitting electrode and the measuring electrode 106 as a receiving electrode.

[0258] exist Figure 5b In the configuration shown, the hand is connected to ground potential M via switch 502: the hand 102 is therefore polarized at ground potential M. At the same time, the measuring electrode 106 is connected to the power supply 302 via switch 504: the measuring electrode 106 is therefore polarized at potential V1. This configuration makes it possible to perform a common capacitance detection step to detect the presence or absence of any nearby object, in particular the presence or absence of the hand 102 and / or a second object 104, both of which are polarized at ground potential M. The detection performed at frequency F1 is a self-capacitance detection.

[0259] Now refer to Figure 6 to Figure 7b Other specific embodiment examples are described. In these figures, and without limitation, the second nearby object 104 is considered to be the operator's hand and the first nearby object 102 is any other object that can be found in the environment of the equipment, in the illustrated case, the robot, such as a table, a support, a workbench, another robot, etc. In particular, the first object can be a workbench on which the robot performs operations.

[0260] Figure 6 is a schematic diagram of an example of an embodiment for performing the distinctive capacitance detection step.

[0261] Figure 6 The example 600 shown in enables distinctive capacitive detection of the hand 104 (which corresponds to the second nearby object) to be performed.

[0262] For this purpose, the hand 104 is polarized at a ground potential M. The first object 102 and the capacitive electrode 106 are polarized at a potential V1 having a frequency F1 , which is delivered by the power supply 302 and which is different from the ground potential M at said frequency F1 .

[0263] Under these conditions, the first object 102 is electrically invisible to the measuring electrode 106 , since it is at the same electrical potential as the measuring electrode 106 .

[0264] This example 600 makes it possible to perform a differential capacitance detection step to detect the presence or absence of a hand 104 at a frequency F1, the hand being grounded, changing the capacitance seen by the measurement electrode 106. The detection performed is a self-capacitance detection.

[0265] However, this example 600 does not perform the common capacitance detection step.

[0266] Figure 7a and Figure 7b are schematic diagrams of two configurations of examples that make it possible to perform the distinctive capacitance detection step and the common capacitance detection step using a single power supply.

[0267] In particular, Figure 7a represents a configuration that enables distinctive capacitive detection of the hand 104 alone to be performed, and Figure 7b 104 represents a configuration that enables common capacitance detection of any object including the hand 104 to be performed indiscriminately.

[0268] exist Figure 7a and Figure 7b In the example represented in , a single power source is used, namely the power source 302 which delivers an alternating potential V1 at a frequency F1.

[0269] Regardless of the configuration, the hand 104 (which corresponds to the second object 104 ) is polarized at ground potential M.

[0270] Whatever the configuration, the measurement electrode 106 is polarized at the potential V1 delivered by the source 302 .

[0271] Switch 702 is used to Figure 7a The configuration represented in Figure 7b In particular, the switch 702 selectively connects the first object to the potential V1 delivered by the source 302 or to the ground potential M.

[0272] exist Figure 7aIn the configuration shown, the first object 102 is connected to the source 302 via the switch 702: the first object 102 is therefore polarized at the potential V1, like the measuring electrode 106. The first object is therefore electrically invisible to the measuring electrode 106 at the frequency F1 of V1. This configuration makes it possible to perform a distinctive capacitive detection step to detect the presence or absence of the hand 104 alone at the frequency F1. The detection performed at the frequency F1 is a self-capacitive detection, since the hand polarized at the ground potential M changes the capacitance seen by the measuring electrode 106.

[0273] exist Figure 7b In the configuration shown, the first object is connected to ground potential M via switch 702: the first object 102 is therefore polarized at ground potential M, just like the hand 104. This configuration makes it possible to perform a common capacitance detection step at frequency F1 to detect the presence or absence of nearby objects, in particular the presence or absence of the first object 102 and / or the hand 104, both of which are polarized at ground potential M. The detection performed at frequency F1 is a self-capacitance detection.

[0274] Of course, the invention is not limited to the embodiments that have just been described, and various modifications can be made to these embodiments without exceeding the scope of the invention.

Claims

1. A method for capacitance detection of nearby objects (102, 104) located in an environment of equipment equipped with a capacitance detection device (100), the capacitance detection device comprising: - at least one capacitive electrode (106), which is called a measuring electrode; as well as - detection electronics (110) for polarizing at least one measuring electrode (106) at an electric potential and measuring at least one signal (V) representative of the capacitance seen by the at least one measuring electrode (106), referred to as the electrode-object capacitance S ); Characterized in that the method comprises a step of selectively detecting nearby objects (102, 104) called a distinctive detection step, which comprises the following operations: - polarizing the first nearby object (102) at least at a first alternating potential (V1) different from ground potential (M) and different from the potential of at least one second nearby object (104) at at least a first frequency (F1); and - determining a first distinctive signal representing the capacitance, called electrode-object capacitance, seen by the at least one measuring electrode at the first frequency (F1).

2. The method according to claim 1, characterized in that The method includes polarizing at least one second object (104) at ground potential (M) during the distinctive detection step.

3. The method according to claim 1 or 2, characterized in that: The method comprises polarizing at least one second object (104) at a second alternating potential (V2) at a second frequency (F2) different from the first frequency (F1) during the differential detection step.

4. The method according to claim 1 or 2, characterized in that: The method comprises polarizing at least one second object (104) at the first frequency (F1) during the differential detection step, at a potential having the same frequency as the first alternating potential (V1) and being orthogonal to the first alternating potential (V1).

5. The method according to claim 1 or 2, characterized in that: During the differential detection step, the at least one measuring electrode (106) is polarized at ground potential (M).

6. The method according to claim 3, characterized in that During the differential detection step, the at least one measuring electrode (106) is polarized at a third alternating potential.

7. The method according to claim 6, characterized in that During the differential detection step, the third polarization potential (V0): - is different from the first polarization potential at the first frequency (F1), and - where applicable, different from a second polarization potential at a second frequency (F2).

8. The method according to claim 6, characterized in that The third potential is the same as the first polarization potential at the first frequency (F1), or the same as the second polarization potential at the second frequency (F2).

9. The method according to claim 3, characterized in that: The method further comprises a step of detecting nearby objects (102, 104), referred to as a co-detection step, which comprises the following operations: - polarizing at least one measuring electrode at an alternating potential, called working potential, at a frequency, called working frequency, which is different from ground potential (M) and from the potential of the first and second nearby objects; as well as - determining a common signal which represents the capacitance seen by at least one measuring electrode at the operating frequency, referred to as the electrode-object capacitance.

10. The method according to claim 9, characterized in that During the co-detection step: - said operating frequency is identical to the first frequency (F1) and, at said frequency (F1), said operating potential is identical to the first polarization potential of the first object (102) during the differential detection step, or - where applicable, the operating frequency is the same as the second frequency and at this frequency the operating potential is the same as the second polarization potential of the second object (104); The distinctive detection step and the common detection step are performed sequentially, and the method includes the step of changing the potential of the first object (102) or the second object (104) between the detection steps.

11. The method according to claim 9, characterized in that Working potential used during the common detection step: - a polarization potential of the object (102, 104) at a first frequency (F1) different from that used during the differential detection step; and - where applicable, a second polarization potential different from the second frequency; The distinctive detection step and the common detection step are performed simultaneously, so that a common detection signal and one or more distinctive detection signals are determined from the same measurement signal.

12. The method according to claim 11, characterized in that At least one nearby object (102, 104) is polarized in wired connection with a power source (302) that supplies power to a capacitance detection device.

13. The method according to claim 11, characterized in that At least one nearby object (102, 104) is polarized by a power source (302) that is independent of a power source (402) that powers a capacitance detection device (100), the method further comprising exchanging wireless signals between the power source that powers the capacitance detection device and the power source that is independent of the power source that powers the capacitance detection device for: - synchronizing the power supply for supplying power to the capacitance detection device and the power supply (302, 402) independent of the power supply for supplying power to the capacitance detection device with each other; or - acquiring the frequency and / or phase of the polarization signal of the at least one nearby object (102).

14. The method according to claim 10, characterized in that The first object (102) is at least a portion of a body of a human operator.

15. The method according to claim 10, characterized in that: The first object (102) is a working area facing equipment, and the second object (104) is at least a part of a body of a human operator.

16. The method according to claim 14, characterized in that The first object (102) is a hand or an arm of the operator.

17. The method according to claim 15, characterized in that The equipment is a table, a workbench, a belt conveyor.

18. A capacitance detection device (200; 300; 310; 400; 500; 600; 700) for equipment, the capacitance detection device comprising: - at least one capacitive electrode (106), which is called the measuring electrode, and - detection electronics (110) for polarizing at least one measuring electrode (106) and measuring at least one signal representative of the capacitance seen by the at least one measuring electrode (106), referred to as electrode-object capacitance; as well as - means for polarizing at least one nearby object (102, 104); The capacitance detection device is arranged to implement all steps of the method according to any one of claims 1 to 17 .

19. The device (400) according to claim 18, characterized in that include: - a first power source (302) for polarizing the first object (104); as well as - a second source for supplying power to the detection electronics (110) independently of said first power source.

20. The device (500; 700) according to claim 18, characterized in that A single power source (302) is included for sequentially polarizing: - at least one nearby object (102; 104), and - measuring electrodes (106); The device (500) also includes means for sequentially connecting and disconnecting the single power source to the nearby object and the measurement electrode.

21. An installation provided with a capacitance detection device according to any one of claims 18 to 20.

22. The apparatus according to claim 21, characterized in that The equipment is of robotic type.

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