Title: device for detecting one or more moving targets, and apparatus and vehicle equipped with such a device

Abstract

The invention relates to a device (300) for detecting one or more disruptive magnetic targets (102) moving in a direction of travel, the device (300) comprising a measurement head (202) comprising: - a first sensor (2041) of variable reluctance, VR, comprising a first coil (2101) and a magnet (2061), and - a second sensor (2042) of variable reluctance, VR, comprising a second coil (2102) and a magnet (2062), spatially offset with respect to the first VR sensor (2041) in the direction of travel; the VR sensors (2041; 2042) being arranged in differential mode. The invention also relates to an apparatus, and in particular a wheel, equipped with a device according to the invention, and to a vehicle equipped with a device according to the invention.

Description

DESCRIPTION Title: Moving target detection device(s), device and vehicle equipped with such a device

[0001] The present invention relates to a device for detecting moving target(s). It also relates to an apparatus, and in particular a wheel, and a vehicle equipped with such a device.

[0002] The field of the invention is generally the field of variable reluctance sensors used for the detection of a target and / or for the measurement of the position and / or speed and / or acceleration of a target or a part containing said target. State of the art

[0003] Variable reluctance devices are known for measuring speed, particularly the rotational speed of a wheel. These devices include a variable reluctance sensor designed to be positioned opposite a patterned wheel, such as a toothed or slotted wheel. The variable reluctance sensor consists of a coil wound around a ferromagnetic core coupled to a magnet, and detects the passage of each pattern on the wheel as it rotates. Knowing the position and / or number of patterns on the wheel, it is possible to deduce the wheel's rotational speed from the detected patterns.

[0004] However, currently known variable reluctance devices are inaccurate, or non-functional, when the speed to be measured is low because the amplitude of the detection signal provided by the variable reluctance sensor depends on the speed at which the patterns are moving. Similarly, as the distance between the variable reluctance sensor and the wheel increases, the detection accuracy becomes low or even insufficient, rendering the sensor non-functional. Furthermore, these devices are highly sensitive to the environment, particularly the Earth's magnetic field, making their use unreliable.

[0005] One objective of the present invention is to remedy at least one of the aforementioned drawbacks.

[0006] Another aim of the invention is to provide a more precise, more reliable and more efficient target detection device. Description of the invention

[0007] The invention proposes to achieve at least one of the aforementioned goals by means of a device for detecting magnetic disruptive target(s) moving along a scrolling direction, said device comprising at least one measuring head including: -a first variable reluctance sensor, RV, comprising a first coil and a magnet; and -a second variable reluctance sensor, RV, comprising a second coil and a magnet, spatially offset from said first sensor RV in said scrolling direction; said RV sensors being arranged in differential mode.

[0008] The target detection device according to the invention comprises not one, but two RV sensors. The use of two RV sensors in a measuring head makes it possible to obtain two values ​​for the detection of the same target as it passes in front of the measuring head.

[0009] Furthermore, and most importantly, the invention proposes to arrange the two RV sensors in differential mode: -either by assembly, -either at the level of a detection electronics which reverses the signal provided by one of said RV sensors. The differential mode arrangement of the RV sensors allows for a detection signal corresponding to, or a function of, a differential signal representing the difference between the detections of the two RV sensors. This makes it possible to reject all external magnetic disturbances that could interfere with the detection device. For example, the differential mode eliminates the disturbance due to the Earth's magnetic field: indeed, this external disturbance is detected by each of the sensors, and the differential mode allows for the rejection of said disturbance. This reasoning is valid for all magnetic disturbances due to sources external to the two RV sensors of the device according to the invention. Thus, the solution proposed by the invention is more precise, more reliable, and more efficient compared to current solutions because it provides a better signal-to-noise ratio compared to current solutions.

[0010] By "target" we mean any object, or any shape intended on an object.

[0011] The target can be a single, independent piece.

[0012] The target can be a part attached to or added to an organ, or another part. For example, the target can be formed by adding a part to an organ.

[0013] The target may be, or include, a shape provided within a part or component. For example, the target may be a pattern formed directly within said component or part, such as a tooth, boss, recess, indentation, bore, etc. In particular, a target may be formed by each tooth of a gear, rack, rotating shaft, etc. These examples are given for illustrative purposes only and are not exhaustive.

[0014] A "magnetic interference target" is defined as any target formed by, or comprising, a material capable of disturbing the magnetic field flux when positioned opposite or in the immediate vicinity of an RV sensor. Alternatively, a magnetic interference target may be formed by the absence of magnetic interference material in a part itself formed by, or comprising, a magnetic interference material. According to yet another alternative, a "magnetic interference target" may be formed by a first magnetic interference material within a part made of, or comprising, a second magnetic interference material, creating a disturbance in the magnetic flux different from that of the second magnetic interference material.

[0015] The term "magnetic interference material" refers to any material, or composite of materials, that alters the magnetic field flux. For example, a magnetic interference material can be metallic, magnetic, ferromagnetic, ferritic, paramagnetic, or diamagnetic.

[0016] By "differential mode" we mean a configuration in which the sum of the signals provided by the RV sensors cancels out when a target is located between said two RV sensors, at an equal distance from said RV sensors.

[0017] In some embodiments, the magnet of at least one, and in particular of each, RV sensor can be a permanent magnet. This allows for a compact architecture for the device according to the invention, with reduced power consumption. In particular, in this embodiment, the power consumption of the measuring head is very low, or even zero.

[0018] Depending on the embodiment, the magnet of at least one, and in particular of each, RV sensor can be an electromagnet.

[0019] Of course, the magnet of at least one, and in particular of each, RV sensor may be another type of magnet.

[0020] The measuring head of the device according to the invention comprises at least two RV sensors.

[0021] Of course, the invention is not limited to a measuring head comprising two RV sensors and the measuring head may comprise more than two RV sensors.

[0022] According to embodiments, at least one RV sensor may include a magnet coupled to a ferromagnetic core around which the coil of said RV sensor is wound.

[0023] This implementation method allows for a simple architecture that can be implemented with existing components.

[0024] According to some embodiments, at least one RV sensor may include a magnet around which the coil of said RV sensor is wound, without the use of a ferromagnetic core.

[0025] This embodiment allows for a simple architecture that can be implemented with existing components, while also enabling a more compact and less expensive architecture because it avoids the use of a ferromagnetic core.

[0026] Depending on the embodiment, each RV sensor can have an individual magnet independent of the magnet of the other RV sensor.

[0027] This implementation method allows for a simple architecture that can be implemented with existing components.

[0028] In some embodiments, the RV sensors may have a common magnet. In other words, in this embodiment, the RV sensors do not include individual magnets: the measuring head has a single magnet common to both RV sensors.

[0029] This embodiment allows for a simple architecture that can be implemented with existing components, while also enabling a more compact and less expensive architecture because it saves the need for a magnet.

[0030] In this embodiment, the measuring head comprises a single magnet connected to two ferromagnetic cores: one for each RV sensor. The coil of each RV sensor is wound around the respective ferromagnetic core of said RV sensor.

[0031] As mentioned above, the invention proposes using two RV sensors in differential mode. This feature makes it possible to eliminate external disturbances, also known as common noise, which apply to the two RV sensors.

[0032] This differential mode for the two RV sensors can be obtained in different ways and the invention is not limited to a specific way of obtaining the differential mode between the RV sensors.

[0033] According to embodiments, the RV sensors can be mounted in the same direction so as to provide electrical voltages of the same sign when a target is located in the middle of said sensors, said device further comprising detection electronics realizing the difference between the detection signals, and in particular the detection voltages, provided by said RV sensors.

[0034] In this case, the differential mode configuration of the RV sensors is obtained through the detection electronics which performs the difference between the measurement signals provided by said RV sensors.

[0035] According to some embodiments, the RV sensors can be mounted in opposite directions so as to provide electrical signals, and in particular electrical voltages, of opposite signs which cancel each other out when a target is in the middle of said sensors.

[0036] In this case, the RV sensors provide detection signals, and in particular electrical voltages, of opposite signs. Thus, their sum cancels out when the target is located between the two RV sensors at an equal distance from said RV sensors.

[0037] The opposite mounting of two RV sensors can be achieved in different ways and the invention is not limited to a specific method of opposite mounting of RV sensors.

[0038] Following one embodiment, the RV sensors can include one or more magnets of the same orientation and windings of opposite orientation. Thus, the RV sensors are mounted in opposite directions and provide measurement signals that cancel each other out when the target is located between the two RV sensors at an equal distance from said RV sensors.

[0039] In another embodiment, the RV sensors can have magnets with opposite orientations and windings with the same orientation. Thus, the RV sensors are mounted in opposite directions and provide measurement signals that cancel each other out when the target is located between the two RV sensors at an equal distance from said RV sensors.

[0040] According to embodiments, the device according to the invention may include detection electronics to receive the detection signal(s) provided by the measuring head.

[0041] This detection electronics can be digital, or analog, or a combination of at least one digital component and at least one analog component.

[0042] The detection electronics can implement one or more functions.

[0043] Depending on the embodiment, the detection electronics may include an integrator.

[0044] The integrator's function is to integrate the differential signal provided by the differential mode configuration of the RV sensors, that is, the difference between the detection signals provided by the two RV sensors.

[0045] Such an integrator makes it possible to obtain a detection signal whose amplitude does not depend on the speed of movement of the target(s).

[0046] However, the detection signal provided by the integrator still depends on the distance between the measuring head and the target(s). In particular, the amplitude of the detection signal is inversely proportional to, or varies inversely with, the distance between the measuring head and the target(s).

[0047] Advantageously, the device according to the invention, and in particular the detection electronics, may include a computing module providing a target position value as a function of the detection signal.

[0048] Thus, according to embodiments, the device according to the invention can be used to determine the position of the target.

[0049] Indeed, using two RV sensors, particularly in differential mode, allows for the precise determination of the target's position in the direction of travel. When the signal obtained is zero, it indicates that the target is equidistant from the RV sensors. This signal reaches a maximum when the target is facing one of the two RV sensors and a minimum when the target is facing the other. Thus, it is possible to determine the target's position from the detection signal.

[0050] Advantageously, the device according to the invention, and in particular the detection electronics, may include a calculation module providing a speed value as a function of the detection signal.

[0051] Thus, according to embodiments, the device according to the invention can be used to determine the speed of the target.

[0052] Knowing the distance between two targets, and the time elapsed between the detection of these two targets, it is possible to deduce the speed of movement of said targets, and where applicable the speed of movement, and in particular the speed of rotation or translation, of a part containing said targets.

[0053] In the case of a single target, it is possible to detect the target's movement speed using at least two measuring heads. Knowing the distance between these two measuring heads and the time elapsed between the target's detection by each of them, it is possible to deduce the target's movement speed, and consequently the movement speed, and where applicable, the rotational or translational speed, of a part containing the target.

[0054] Advantageously, the device according to the invention, and in particular the detection electronics, may include a computing module providing an acceleration value of the target as a function of the detection signal.

[0055] Thus, according to embodiments, the device according to the invention can be used to determine the acceleration of the target.

[0056] According to embodiments, the device according to the invention may comprise a single measuring head.

[0057] Thus, the architecture of the detection device is simple, compact and inexpensive.

[0058] According to embodiments, the device according to the invention may include several measuring heads distributed in the direction of scrolling, each measuring head comprising at least two RV sensors used in differential mode.

[0059] Thus, the detection device can make it possible to obtain the directions of rotation, translation, and more generally of scrolling of targets and also to carry out more precise, more redundant, and therefore more robust measurements.

[0060] In this case, the device according to the invention may include common detection electronics for at least two measuring heads, if necessary.

[0061] Alternatively, or in addition, the device according to the invention may include individual sensing electronics for at least one and in particular each of at least two measuring heads, as appropriate.

[0062] According to embodiments, the measuring head can be positioned facing at least one target so that the aiming direction of the RV sensors is parallel to, or is included in, the plane comprising the scrolling direction of at least one target.

[0063] In this case, the measuring head, and therefore the RV sensors of the measuring head, face the target.

[0064] According to embodiments, the measuring head can be positioned laterally to at least one target so that the aiming direction of the RV sensors is not parallel, and in particular is perpendicular, to the plane comprising the scrolling direction of at least one target.

[0065] In this case, the measuring head, and therefore the RV sensors of the measuring head, is / are positioned laterally to the target, or targets.

[0066] According to another aspect of the same invention, a device equipped with: -of a moving part, rotating or translating, comprising targets, and -of a device according to the invention for measuring the speed of said part by detecting said targets.

[0067] Such a device can be of any type.

[0068] Such a device can be equipment for another device, machine, or vehicle.

[0069] The detection device according to the invention equipping the device according to the invention can be equipped with one or more measuring heads.

[0070] According to embodiments, the detection device according to the invention equipping the device according to the invention can be equipped with a single measuring head.

[0071] According to embodiments, the detection device according to the invention equipping the device according to the invention can be equipped with several measuring heads.

[0072] In this case, preferably, the multiple measuring heads can be distributed in, or along, the direction of the target's movement. This allows for more precise velocity measurements, as they can be confirmed by multiple measuring heads, each providing a detection signal. Furthermore, velocity measurements can be performed more robustly, as it is possible to compensate for the failure of one of the measuring heads. The direction of rotation, translation, and, more generally, the direction of movement of the target can also be detected.

[0073] At least two consecutive measuring heads can be offset by a predetermined distance, or angular distance.

[0074] Preferably, at least two measuring heads can be offset by a distance, denoted d without loss of generality, corresponding to a fraction, denoted f without loss of generality, of the separation step, denoted p without loss of generality, between two consecutive targets, modulo an integer step, denoted n without loss of generality, with n > 0. Thus, it is possible to have detection signals offset by a phase value, denoted A0 without loss of generality, corresponding to A0 = fp360°

[0075] According to an advantageous embodiment, at least two measuring heads can be offset by a distance d such that d=n.p+(p / 4): in this case f=l / 4. This embodiment makes it possible to obtain a sine detection signal on one of the detection heads and a cosine detection signal on the other of the detection heads.

[0076] This embodiment is simple to implement and also allows other data to be deduced from the detection signals, such as the direction of movement, or rotation, of the moving part, the position of the target, etc.

[0077] In this embodiment, one of the measuring heads provides a sine detection signal, and the other provides a cosine signal. From these signals, for example, it is possible to obtain a magnitude and an angle by calculating arctan(sin / cos), which allows determining a value relative to the target's position.

[0078] Following examples of embodiment, the device according to the invention can be a wheel for a vehicle.

[0079] According to another aspect of the same invention, a vehicle is proposed equipped with an apparatus according to the invention, or with a device according to the invention.

[0080] The vehicle according to the invention can be any type of vehicle.

[0081] In particular, the vehicle according to the invention can be a land vehicle, such as a car, a truck, a bus, a coach, etc.

[0082] The vehicle according to the invention can be a railway vehicle, such as a locomotive, a train, a tram, etc.

[0083] The vehicle according to the invention can be a maritime vehicle, such as a boat, a passenger liner, a ship, a submarine, etc.

[0084] The vehicle according to the invention can be a flying vehicle, such as an airplane, a helicopter, a drone, etc.

[0085] The vehicle according to the invention can be a space vehicle, such as a rocket, a satellite, etc.

[0086] Following a non-limiting example of embodiment, the vehicle may be an aircraft equipped with a wheel according to the invention.

[0087] According to non-limiting embodiments, the vehicle can be equipped with a wheel according to the invention.

[0088] According to non-limiting embodiments, the vehicle can be equipped with a rotating shaft and a detection device according to the invention for measuring the rotational speed of said rotating shaft.

[0089] According to non-limiting embodiments, the vehicle can be equipped with a rack and a detection device according to the invention for measuring the speed of movement of said rack.

[0090] According to non-limiting embodiments, the vehicle can be equipped with a toothed wheel and a detection device according to the invention for measuring the rotational speed of said toothed wheel. Description of the figures and methods of realization

[0091] Other advantages and features will become apparent upon examination of the detailed description of non-limiting embodiments and the accompanying drawings, in which: - FIGURE 1 is a schematic representation of a non-limiting example of a detection device according to the state of the art; -FIGURES 2-7 are schematic representations of non-limiting examples of embodiments of a detection device according to the invention; -FIGURES 8a and 8b are schematic representations of non-limiting examples of configurations of a detection device according to the invention; -Figure 9 is a schematic representation of a non-limiting example of a wheel according to the invention; and - FIGURE 10 is a schematic representation of a non-limiting example embodiment of a vehicle according to the invention.

[0092] It is understood that the embodiments described below are by no means exhaustive. In particular, variants of the invention may be conceived comprising only a selection of features described hereafter, isolated from the other described features, if this selection of features is sufficient to confer a technical advantage or to differentiate the invention from the prior art. This selection includes at least one preferably functional feature without structural details, or with only a portion of the structural details if this portion alone is sufficient to confer a technical advantage or to differentiate the invention from the prior art.

[0093] In particular, all the variants and embodiments described can be combined with each other if there are no technical obstacles to this combination.

[0094] In the figures and in the rest of the description, elements common to several figures retain the same reference.

[0095] FIGURE 1 is a schematic representation of a non-limiting example embodiment of a prior art target detection device.

[0096] The device 100 in FIGURE 1 can be used to detect a target capable of disrupting the magnetic field flux.

[0097] In the example shown in FIGURE 1, the device 100 is used to detect the teeth 102 provided on a rotating part 104 around a rotation axis 106: thus, each tooth 102 of the rotating part 104 is a target. It should be noted that the rotating part 104, equipped with teeth 102, is not part of the device 100.

[0098] The prior art device 100 comprises a variable reluctance sensor 110, referred to hereafter as sensor RV. In the example shown, the sensor RV 110 includes a magnet 112 magnetically coupled to a ferromagnetic core 114. A coil 116 is wound around the ferromagnetic core 114. The voltage across the coil 116 depends on the magnetic flux, and in particular on the change in magnetic flux. Thus, if the reluctance of the sensor RV 110 is changed, this changes the magnetic flux through the magnet 112 and therefore the voltage across the coil 116.

[0099] In operation, the RV 110 sensor is positioned opposite the rotating part 104 so that each tooth 102 of said rotating part 104 passes in front of and in the immediate vicinity of the RV 110 sensor during the rotation of said part 104. Thus, the targets formed by the teeth 102 move along a rotating path in front of the RV 110 sensor during the rotation of the rotating part 104. When a tooth passes in front of the RV 110 sensor, this changes the reluctance of the RV sensor, and therefore the magnetic field flux, which generates an electrical detection signal, and in particular an electrical voltage Vs supplied by the RV 110 sensor. Generally, the detection signal supplied by the RV 110 sensor is an electrical pulse Vs each time a tooth 102 passes in front of the RV 110 sensor, as shown in FIGURE 1.

[0100] The device 100 in Figure 1 detects the passage of each tooth 102 but has drawbacks. It is inaccurate when the rotational speed of the workpiece 104 is low because the amplitude of the detection signal Vs provided by the sensor RV 110 depends on the speed of the teeth 102. Similarly, as the distance between the sensor RV 110 and the rotating workpiece 104 increases, the detection accuracy becomes low or even insufficient. Finally, and most importantly, the sensor RV 110 is very sensitive to the environment, particularly the Earth's magnetic field, making the use of device 100 unreliable.

[0101] FIGURE 2 is a schematic representation of a non-limiting example embodiment of a target detection device according to the invention.

[0102] The device 200 in FIGURE 2 can be used to detect any target that disturbs the magnetic field flux. Such a target can be made of, or include, any material capable of disturbing the magnetic field flux, such as, for example, a metallic, magnetic, ferromagnetic, ferritic, paramagnetic, diamagnetic, etc., material. These examples are given for illustrative purposes only and are not exhaustive.

[0103] The target can be any type of target. It can be an entire object, a part of an object, or a pre-existing shape on an object. A target can be an additional component attached to another component, or a pre-existing shape within that other component. For example, a target can be formed by adding a metal component to another component. As another example, a target can be formed directly within that other component, for instance, in the form of a tooth or a pattern. In particular, a target can be formed by each tooth of a gear, rack, rotating shaft, etc. These examples are illustrative only and are not exhaustive.

[0104] In the example shown in FIGURE 2, device 200 is used to detect the teeth 102 provided on the rotating part 104: thus, each tooth 102 of the rotating part 104 is a target. It should be noted that the rotating part 104, equipped with teeth 102, is not part of device 200.

[0105] The device 200 includes a measuring head 202 comprising a first RV sensor 204i and a second RV sensor 2042 arranged side by side, on, or along, the path of the teeth 104, at an equal distance from the rotating part 102 and therefore from the teeth 104.

[0106] In the example shown in FIGURE 2, the first sensor RV 204i consists of a magnet 206i magnetically coupled to a ferromagnetic core 208i around which a coil 210i is wound. Under these conditions, the first sensor RV 204i provides a detection signal Vsl when a tooth 104 passes in front of the first sensor RV 202i. The magnet 206i can be any type of magnet, and in particular a permanent magnet or an electromagnet. For the sake of generality, the magnet 206i is considered to be a permanent magnet.

[0107] In the example shown in Figure 2, the second sensor RV 2042 consists of a magnet 2062 magnetically coupled to a ferromagnetic core 2082 around which a coil 2102 is wound. Under these conditions, the second sensor RV 2042 provides a detection signal Vs2 when a tooth 104 passes in front of said second sensor RV 2042. The magnet 2062 can be any type of magnet, and in particular a permanent magnet or an electromagnet. For the sake of generality, the magnet 2062 is considered to be a permanent magnet.

[0108] According to the invention, the two RV sensors 204i and 2042 are used in differential mode in the detection device according to the invention. In the device 200 of FIGURE 2, this differential mode of the RV sensors 204i and 2042 is achieved with a detection electronic 212 connected to the RV sensors 204i and 2042 and, in particular, to the coils 210i and 2102 of the respective RV sensors 204i and 2042. This detection electronic 212 receives the detection signals Vsl and Vs2 and provides a detection signal Vs which corresponds to, or is proportional to, a difference between the signals Vsl and Vs2 such that Vs = f(Vsl - Vs2). In particular, Vs = Vsl - Vs2.

[0109] Under these conditions, that is, in this differential mode operation of the RV 204i and 2042 sensors, all external magnetic disturbances to the device 200 that could interfere with the detection device 200 during target detection are rejected. For example, the differential mode eliminates the disturbance due to the Earth's magnetic field: this external disturbance is detected by each of the sensors, and the differential mode allows for its rejection. This reasoning is valid for all magnetic disturbances due to sources external to the device according to the invention. Thus, the device 200, and more generally the detection device according to the invention, is more precise, more reliable, and more efficient compared to current solutions, and in particular to the device 100 of FIGURE 1.

[0110] The detection electronics 212 can be of any type. Following a very simplified embodiment, the detection electronics 212 may include an inverter for inverting one of the two signals Vs1 and Vs2, for example, the signal Vs2, connected to an adder that adds said inverted signal with the other signal. Of course, this example is given for illustrative purposes only, and the invention is not limited to this example. [YES] In the example of FIGURE 2, the differential mode configuration of the RV 204i and 2042 sensors is obtained by inverting one of the Vsl and Vs2 signals in the sensing electronics 212. Of course, the invention is not limited to this embodiment and the differential mode can be obtained in other ways, as described above.

[0112] FIGURE 3 is a schematic representation of another non-limiting embodiment of a target detection device according to the invention.

[0113] The device 300 of FIGURE 3 includes the measuring head 202 comprising the first sensor RV 204i and the second sensor RV 2042 of the device 200 of FIGURE 2, mounted in differential mode.

[0114] Unlike device 200 in FIGURE 2, in device 300 the coils 210i and 2102 of the RV sensors 204i and 2042 are connected together and directly provide the detection signal Vs, without the use of detection electronics. In particular, -one terminal of the RV 2042 sensor coil 2102 is connected to an electrical ground, for example earth or a reference input such as a floating local ground; and -the other terminal of coil 2102 is connected to a first terminal of coil 210i of sensor RV 204i. The detection signal Vs is provided by the second terminal of the coil 210i of the sensor RV 204i.

[0115] In device 300, the RV sensors 204i and 2042 are configured, and in particular mounted, in differential mode. The differential mode of the RV sensors 204i and 2042 in device 300 can be achieved in different ways. According to one embodiment, the respective magnets 206i and 2062 can be arranged in opposite directions, and the respective coils 210i and 2102 can be wound in the same direction: this embodiment is shown in FIGURE 3. According to another embodiment, the respective magnets 206i and 2062 can be arranged in the same direction, and the respective coils 210i and 2102 can be wound in opposite directions.

[0116] FIGURE 4 is a schematic representation of another non-limiting embodiment of a target detection device according to the invention.

[0117] Device 400 in FIGURE 4 includes all the elements of device 300 in FIGURE 3 except for the differences indicated below.

[0118] Unlike device 300 in FIGURE 3, in device 400 the RV 204i and 2042 sensors comprise a single magnet 402, common to said RV 204i and 2042 sensors. In other words, the RV 204i and 2042 sensors do not each comprise an individual magnet but share the same magnet 402.

[0119] The 402 magnet can be any type of magnet, and in particular a permanent magnet or an electromagnet. In the following, without loss of generality, we will consider the 402 magnet to be a permanent magnet.

[0120] In device 400, the RV 204i and 2042 sensors are configured, and in particular mounted, in differential mode. The differential mode of the RV 204i and 2042 sensors in device 400 is achieved by winding the respective coils 210i and 2102 of said RV 204i and 2042 sensors in opposite directions.

[0121] FIGURE 5 is a schematic representation of another non-limiting embodiment of a target detection device according to the invention.

[0122] Device 500 in FIGURE 5 includes all the elements of device 300 in FIGURE 3 except for the differences indicated below.

[0123] Unlike device 300 in Figure 3, in device 500 the RV sensors 204i and 2042 do not include a ferromagnetic core. In other words, the RV sensor 204i includes the magnet 206i, and the coil 2101 is wound directly onto the magnet 206i without the use of the ferromagnetic core 208i. Similarly, the RV sensor 2042 includes the magnet 2062, and the coil 2IO2 is wound directly onto the magnet 2062 without the use of the ferromagnetic core 2082.

[0124] In device 500, the RV 204i and 2042 sensors are configured, and in particular mounted, in differential mode. The differential mode of the RV 204i and 2042 sensors in device 500 is achieved by winding the respective coils 210i and 2IO2 of said RV 204i and 2042 sensors in opposite directions.

[0125] In the example in FIGURE 5, neither of the RV 204i and 2042 sensors includes a ferromagnetic core. According to an alternative (not shown), one of the RV 204i and 2042 sensors may include a ferromagnetic core, and the other of the RV 204i and 2042 sensors may not include a ferromagnetic core.

[0126] According to examples not shown, it is possible to configure the RV 204i and 2042 sensors of device 500 in differential mode in a sensing electronic, like device 200 in FIGURE 2. According to yet another alternative, the differential mode of the RV 204i and 2042 sensors in device 500 can be obtained by winding the respective coils 210i and 2102 of said RV 204i and 2042 sensors in the same direction and by arranging the respective magnets 206i and 2062 in opposite directions.

[0127] Following examples not shown, it is possible not to use a ferromagnetic core for one of the sensors of devices 200 or 400, like device 500.

[0128] FIGURE 6 is a schematic representation of another non-limiting embodiment of a target detection device according to the invention.

[0129] The device 600 in FIGURE 6 includes the RV sensors 204i and 2042 mounted in differential mode according to one of the options described above with reference to FIGURES 2-5. In other words, the RV sensors 204i and 2042 can be the RV sensors of any of the devices 200, 300, 400, 500 described above with reference to FIGURES 2-5, or of one of the alternatives described above with reference to FIGURES 2-5.

[0130] The device 600 of FIGURE 6 further includes a detection electronics 602 taking as input the detection signal Vs supplied by the measuring head 202, or the measurement signals Vs1 and Vs2 supplied by the measuring head 202, and providing a detection signal Vd.

[0131] The sensing electronics 602 includes an integrator 604 to integrate the Vs signal supplied by the measuring head 202, or a difference of the Vs1-Vs2 signals.

[0132] Following a non-limiting example, the integrator 604 can be implemented with an operational amplifier configured as a load amplifier. The load amplifier can be configured as an inverter with a negative feedback capacitor and a time constant adapted to the speed of the target 102.

[0133] Such an integrator 604 makes it possible to obtain a detection signal whose amplitude does not depend on the speed of movement of the target(s).

[0134] FIGURE 7 is a schematic representation of another non-limiting embodiment of a target detection device according to the invention.

[0135] Device 700 in FIGURE 7 includes all the elements of device 600 in FIGURE 6.

[0136] Furthermore, the device 700, in particular the detection electronics 602, also includes, downstream of the integrator 604, a module 702 for calculating the speed of movement of the targets 102. This module 702 takes as input the detection signal Vd provided by the integrator 604 and provides as output a data Vv giving the value of, or representing, the speed of movement of the targets 102. Indeed, knowing the distance separating two consecutive targets 102 and the time elapsed between the detection of two targets 102, it is possible to calculate the speed of movement of the targets 102 and therefore the speed of the wheel 104.

[0137] Optionally, the device 700, and in particular the detection electronics 602, may further include, downstream of the integrator 604, a module (not shown) for calculating the position of each target as it passes in front of the measuring head 202. This position calculation module takes as input the detection signal Vd provided by the integrator 604 and provides as output a data Vp giving the value of, or representing, the position of the target 102 passing in front of the measuring head.

[0138] Optionally, the device 700, and in particular the detection electronics 602, may further include, downstream of the integrator 604, a module (not shown) for calculating the acceleration of the targets 102. This acceleration calculation module takes as input the detection signal Vd provided by the integrator 604 and provides as output a data Va giving the value of, or representing, the acceleration of the targets 102 passing in front of the measuring head.

[0139] Optionally, the device 700, and in particular the detection electronics 602, may further include, downstream of the integrator 604, a module (not shown) for determining the direction of movement of the targets 102. This module for determining the direction of movement takes as input the detection signal Vd provided by the integrator 604 and provides as output a data Vsens giving the value of, or representing, the direction of movement, in rotation or in translation, of the targets 102 passing in front of the measuring head 202.

[0140] In the examples described, the device according to the invention is shown in a configuration in which the measuring head 202 faces the targets 102 as they pass in front of said measuring head. In other words, the aiming direction of the measuring head 202, and therefore of the RV sensors 204i and 2042, is parallel to, and in particular contained within, the plane comprising the direction of travel. For example, in the case of the rotating part 104, the aiming direction of the RV sensors is perpendicular to the axis of rotation of the rotating part. Of course, the invention is not limited to this configuration.

[0141] FIGURE 8a is a schematic representation of another example of a non-limiting configuration of a target detection device according to the invention.

[0142] The target detection device shown in FIGURE 8a is, without limitation, device 700 of FIGURE 7. Alternatively, the device in FIGURE 8 can be any one of the devices in FIGURES 2-7 and more generally a detection device according to the invention.

[0143] In the 800 configuration of FIGURE 8a, the measuring head 202 is positioned laterally to the targets 102 as they pass in front of said measuring head. In other words, the sighting direction of the measuring head 202, and therefore of the RV sensors 204i and 2042, is parallel to the axis of rotation 106 of the rotating part 104.

[0144] Of course, other configurations of the measuring head are possible and the invention is not limited to the configuration described with reference to FIGURES 2-7, nor to the configuration described with reference to FIGURE 8a.

[0145] In all the examples described above, the device according to the invention comprises a single measuring head 202. Of course, the invention is not limited to a single measuring head and the device according to the invention may comprise several measuring heads, identical or different.

[0146] FIGURE 8b is a schematic representation of another example of a non-limiting configuration of a target detection device according to the invention.

[0147] The target detection device of configuration 810 shown in FIGURE 8a can be any one of the devices in FIGURES 2-7 and more generally a detection device according to the invention.

[0148] In the configuration shown in FIGURE 8b, the detection device according to the invention comprises two measuring heads 202i and 2022, each equipped with two RV sensors. The measuring heads 202i and 2022 are arranged along the direction of travel, laterally to the targets, in a manner similar to the configuration in FIGURE 8a. According to an alternative (not shown), at least one of the measuring heads 202i and 2022 can be positioned facing the targets 102, in a manner similar to the configuration in FIGURES 2-7.

[0149] The two measuring heads 202i and 2022 are separated by a distance d, along said trajectory of target movement.

[0150] Part 104 has several targets 102 separated by a constant pitch p.

[0151] Following an advantageous but by no means limiting configuration, the distance d separating the two measuring heads 202i and 2022 can be chosen such that d = p(n + l / 4), where n is an integer n > 0. In other words, the second measuring head 2022 is separated from the first measuring head 2021 by a distance d equal to np, plus a quarter step p. In the configuration shown in FIGURE 8b, the two measuring heads 202i and 2022 are separated by an angular distance d = p(4 + l / 4) such that n = 4

[0152] This arrangement allows the two measuring heads to produce sinusoidal detection signals, 90° out of phase. In other words, the detection signals obtained with the two measuring heads correspond to a sine wave and a cosine wave.

[0153] Such signals allow a simple and practical measurement of the speed of the targets moving and therefore of the speed of rotation of part 104, but also to know the direction of rotation of said part 104.

[0154] FIGURES 9 is a schematic representation of a non-limiting example embodiment of a device according to the invention.

[0155] The device 900 includes a moving part, rotating or translating, comprising targets to be detected. In particular, the device 900 includes part 104 having teeth 102.

[0156] The apparatus 900 of FIGURE 9 is equipped with at least one device 902 according to the invention. The device 902 can be any one of the devices 200, 300, 400, 500, 600, 700 of FIGURES 2-7, according to any one of the configurations described above.

[0157] Device 800 can be any type of device, such as, for example, a wheel of a vehicle.

[0158] FIGURE 10 is a schematic representation of a non-limiting example embodiment of a vehicle according to the invention.

[0159] In the example shown in FIGURE 10, vehicle 1000 is an aircraft with a landing gear equipped with several wheels 1002.

[0160] At least one of the wheels 1002 of the aircraft 1000 includes at least one detection device according to the invention and in particular any one of the devices in FIGURES 2-7, according to any one of the configurations described above.

[0161] In the example shown, at least one of the wheels 1002 of the aircraft is a wheel according to the invention and in particular wheel 900 of FIGURE 9.

[0162] Of course, the vehicle according to the invention is not limited to an airplane.

[0163] The vehicle according to the invention can be any type of vehicle.

[0164] In particular, the vehicle according to the invention may be a land vehicle, such as a car, truck, bus, coach, etc. Alternatively, the vehicle according to the invention may be a railway vehicle, such as a locomotive, train, tram, etc. Alternatively, the vehicle according to the invention may be a maritime vehicle, such as a boat, liner, ship, submarine, etc. The vehicle according to the invention may be an flying vehicle, such as an airplane, helicopter, drone, etc. Alternatively, the vehicle according to the invention may be a space vehicle, such as a rocket, satellite, etc.

[0165] In the examples described above, the device according to the invention is used for detecting targets, or patterns, on a rotating moving part. Of course, the invention is not limited to this illustrative example. The device according to the invention can be used to detect, and optionally measure the speed of movement / scrolling, of any moving target that disturbs the magnetic flux. The target(s) can be moving in translation or rotation. For example, a target can be formed by each tooth of a gear, rack, rotating shaft, etc.

[0166] In general, the invention is not limited to the examples just described.

Claims

DEMANDS 1. Device (200;300;400;500;600;700) for detecting magnetic disturbing target(s) (102) moving along a direction of travel, said device (200;300;400;500;600;700) comprising at least one measuring head (202) including: - a first variable reluctance sensor (204i), RV, comprising a first coil (210i) and a magnet (206i), and -a second variable reluctance sensor (2042), RV, comprising a second coil (2IO2) and a magnet (2062), spatially offset from said first sensor RV (204i) in said scrolling direction; said RV sensors (204I;2042) being arranged in differential mode.

2. Device (200;300;400;600;700) according to the preceding claim, characterized in that at least one RV sensor (204I;2042) comprises a magnet (206I,20O2;402) coupled to a ferromagnetic core (2081,2082) around which is wound the coil (2101,2102) of said RV sensor (204I;2042).

3. Device (500) according to any one of the preceding claims, characterized in that at least one RV sensor (204I;2042) comprises a magnet (206I;20Ô2) around which is wound the coil (210I;21Û2) of said RV sensor (204I;2042), without use of a ferromagnetic core.

4. Device (200;300;500;600;700) according to any one of the preceding claims, characterized in that each RV sensor (204I;2042) has an individual magnet (206I;20Ô2) and independent of the magnet of the other RV sensor (204I;2042).

5. Device (400) according to any one of claims 1 to 3, characterized in that the RV sensors (2041;2042) have a common magnet (402).

6. Device (200) according to any one of the preceding claims, characterized in that the RV sensors (204I;2042) are mounted in the same direction so as to provide electrical voltages of the same sign when a target (102) is located in the middle of said sensors (204I;2042), said device (200) further comprising a detection electronic (212;602) realizing the difference of the electrical voltages supplied by said RV sensors (204I;2042).

7. Device (300;400;500;600;700) according to any one of claims 1 to 5, characterized in that the RV sensors (204I;2042) are mounted in opposite directions so as to provide electrical signals, and in particular electrical voltages, of opposite signs which cancel each other out when a target (102) is in the middle of said sensors (204I;2042).

8. Device (300;400;500;600;700) according to the preceding claim, characterized in that the RV sensors (2041;2042) comprise: -one or more magnets of the same orientation and windings of opposite orientation; or -magnets of opposite direction and windings of the same direction.

9. Device (600) according to any one of the preceding claims, characterized in that it comprises a detection electronics (602) receiving the detection signal(s) supplied by the measuring head (202), said detection electronics (602) comprising an integrator (604).

10. Device (700) according to any one of claims 6 or 9, characterized in that the sensing electronics (602) includes a computing module (702) providing a speed value as a function of the sensing signal.

11. Device according to any one of the preceding claims, characterized in that it comprises several measuring heads distributed on the direction of travel, each measuring head comprising at least two RV sensors used in differential mode.

12. Apparatus (900) equipped with: - a rotating or translating moving part (104) comprising targets (102), and -of a device (902) according to any one of the preceding claims for measuring the speed of said part (104) by detecting said targets (102).

13. Apparatus (900) according to the preceding claim, characterized in that the detection device (902) comprises several measuring heads distributed in the direction of movement of the targets (102), at least two measuring heads being offset by a distance, or an angular distance, corresponding to a fraction of the separation step of two consecutive targets, modulo an integer number n of steps, with n>0.

14. Apparatus (900) according to any one of claims 12 or 13, characterized in that the detection device (902) comprises several measuring heads distributed in the direction of the targets' movement, at least two measuring heads being offset by a distance d such that d=n.p+p / 4 to obtain a sine-shaped detection signal, with p the step between two consecutive targets and n an integer such that n>0.

15. Apparatus (900) according to any one of claims 12 to 14, characterized in that it is a wheel for a vehicle.

16. Vehicle (1000) equipped with a wheel according to the preceding claim.

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