Position reliability of magnets in switching devices

Abstract

To provide a switching device having high reliability of the state of the switching device.SOLUTION: A switching device includes: a housing HS; a moveable element slidably installed in the housing HS; and a printed circuit board PCB. A first magnetic sensing element MSE1 and a second magnetic sensing element MSE2 are configured to detect respectively a first magnetic field and a second magnetic field generated respectively by a first magnet C1 and a second magnet C2. The moveable element is closer to the first magnetic sensing element MSE1 and the second magnetic sensing element MSE2 in an engaged position than in a resting position. The pole configuration C1 of the first magnet is opposed to the pole configuration of the second magnet C2, and the first magnetic field is reverse and equal in magnitude to the second magnetic field. The first magnetic sensing element MSE1 and the second magnetic sensing element MSE2 produce respectively a first output signal and a second output signal from the first magnetic field and the second magnetic field.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates generally to magnetic-based contactless switching devices suitable for push buttons and selectors. [Background technology]

[0002] A switching device generally refers to any device that makes or breaks an electrical circuit. All electrical switching devices consist of a set of contacts that open or close when the device is actuated. Switching devices are operated in a variety of ways, from the simplest, manual switches such as household light switches, to more complex switches used in industrial applications. In these cases, the switching device may be operated using an electromagnetic coil as the inductor element to activate the switch with a magnetic sensing element.

[0003] Examples of such applications include, but are not limited to, civil aviation, spaceflight, military applications, and industrial processes where state reliability of switching devices is required to ensure continued performance of the equipment in the event of a partial failure. Such stringent requirements are imposed due to the potential consequences of failure.

[0004] Therefore, there is a demand for switching devices that have a highly reliable state. Summary of the Invention [Problem to be solved by the invention]

[0005] This Summary is provided to introduce concepts related to the present subject matter. This Summary is not intended to identify essential features of the claimed subject matter, nor is it intended for use in determining or limiting the scope of the claimed subject matter. [Means for solving the problem]

[0006] In one embodiment, Housing and a movable element made of a header, a first magnet, and a second magnet, slidably mounted within the housing, the movable element adapted to move relative to the housing between a disengaged position and an engaged position; a printed circuit board having a microcontroller and a top surface mounted in front of it with a first magnetic sensing element and a second magnetic sensing element positioned to face the first magnet and the second magnet; the first and second magnetic sensing elements are configured to detect a first magnetic field and a second magnetic field generated by the first magnet and the second magnet, respectively, and the movable element is closer to the first and second magnetic sensing elements in the engaged position than in the rest position; the polar configuration of the first magnet is opposite to the polar configuration of the second magnet, and the first magnetic field generated by the first magnet is reversed in magnitude relative to the second magnetic field generated by the second magnet; the first magnetic sensing element and the second magnetic sensing element are capable of generating a first output signal and a second output signal from the first magnetic field and the second magnetic field, respectively; The microcontroller is the first output signal falls within a first range of values ​​and the second output signal falls within a second range of values; and when a sum of the first output signal and the second output signal is substantially equal to a predetermined value derived from the difference between the magnitude of the first magnetic field and the magnitude of the second magnetic field; A reliable position of the moving element can be verified; A switching device is provided.

[0007] The switching device allows for robustness of redundant position sensing against external magnetic perturbations. More precisely, the switching device allows for a significant increase in diagnostic range and perturbation rejection by using opposite magnetic polarities between the two redundant input channels of the switching device. This structure allows for the implementation of a simple software-based plausibility check that allows for unambiguous discrimination of magnetic perturbations from actual magnetic measurements.

[0008] Advantageously, this configuration allows for a simple and compact verification system that may be suitable for many applications such as push buttons and selectors, but may also be extended to any application requiring a reliable switching device.

[0009] The opposite polarity configuration ensures that there is a consistent and repeatable pattern for determining whether the switching device has changed state, which cannot be obtained by external perturbations, allowing the switching device to significantly increase diagnostic coverage and perturbation tolerance in the switching function.

[0010] In one embodiment, The microcontroller is if the first output signal is outside the first range of values ​​or if the second output signal is outside the second range of values; and / or if the sum of the first output signal and the second output signal is not substantially equal to a predetermined value; Magnetic perturbations can be detected.

[0011] In one embodiment, the microcontroller can trigger an alarm if a magnetic perturbation is detected.

[0012] In one embodiment, the predetermined value is 0 if the first magnet and the second magnet have the same characteristics.

[0013] In one embodiment, when the switching device is operated, the header is pressed toward the printed circuit board, bringing the first magnet and the second magnet closer to the first magnetic sensing element and the second magnetic sensing element, respectively, which increases the magnetic flux through the magnetic sensing elements and changes the state of the switching device when a threshold is reached.

[0014] In one embodiment, the first and second magnetic sensing elements are omni-polar sensors that can distinguish magnetic north from magnetic south poles.

[0015] In one embodiment, a first magnetic sensing element is aligned with a first magnet and a first inductor, and a second magnetic sensing element is aligned with a second magnet and a second inductor.

[0016] In another embodiment, there is provided a method for verifying a reliable position of a movable element of a switching device comprising a housing, the movable element being made of a header, a first magnet, and a second magnet and slidably mounted within the housing, the movable element being adapted to move relative to the housing between a released position and an engaged position, the switching device further comprising a printed circuit board having a microcontroller and a top surface forwardly mounted with first and second magnetic sensing elements positioned to face the first and second magnets, the method comprising: the first magnetic sensing element and the second magnetic sensing element respectively detect a first magnetic field and a second magnetic field generated by a first magnet and a second magnet, respectively, and the movable element is closer to the first magnetic sensing element and the second magnetic sensing element in the engaged position than in the rest position; the polar configuration of the first magnet is opposite to the polar configuration of the second magnet, and a first magnetic field generated by the first magnet is reversed and equal in magnitude to a second magnetic field generated by the second magnet; the first and second magnetic sensing elements generate first and second output signals from the first and second magnetic fields, respectively; The microcontroller is the first output signal falls within a first range of values ​​and the second output signal falls within a second range of values; and when a sum of the first output signal and the second output signal is substantially equal to a predetermined value derived from the difference between the magnitude of the first magnetic field and the magnitude of the second magnetic field; Verifying reliable positions of moving elements; This includes:

[0017] In another embodiment, there is provided a computer readable medium having embodied thereon a computer program for verifying a trusted position of a moving element of a switching device, said computer program comprising instructions for performing steps according to a method according to the invention. [Brief explanation of the drawings]

[0018] The detailed description will be described with reference to the accompanying drawings. In the drawings, the leftmost digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawings to refer to like features and components. Some embodiments of systems and / or methods according to embodiments of the present subject matter will now be described, by way of example only, with reference to the accompanying drawings.

[0019] [Figure 1] 1 shows a schematic block diagram of a switching device according to one embodiment;

[0020] [Figure 2] FIG. 1 illustrates a crossed input monitoring routine within a switching device according to one embodiment.

[0021] [Figure 3a] FIG. 10 is a diagram showing a function of the magnetic field B. [Figure 3b] 10A and 10B are diagrams illustrating the behavior of different output signals from a first sensing element MSE1 and a second magnetic sensing element MSE2. [Figure 4]1 is a flow diagram of a method for a crossed input monitoring of a magnetic sensing element of a switching device according to one embodiment.

[0022] The same reference numbers represent the same element or the same type of element in all drawings.

[0023] Those skilled in the art should understand that any block diagrams herein represent conceptual views of illustrative systems embodying the principles of the present subject matter. Similarly, any flowcharts, flow diagrams, state transition diagrams, pseudocode, etc., may be substantially represented on a computer-readable medium and will be understood to represent various processes that may be performed by a computer or processor, whether or not such a computer or processor is explicitly shown. DETAILED DESCRIPTION OF THE INVENTION

[0024] The drawings and the following description illustrate specific exemplary embodiments of the present invention. It will therefore be understood that those skilled in the art can devise various configurations that, although not explicitly described or shown herein, embody the principles of the present invention and are included within the scope of the present invention. Furthermore, any examples described herein are intended to aid in the understanding of the principles of the present invention and should not be construed as being limited to such specifically recited examples and conditions. As a result, the present invention is not limited to the specific embodiments or examples described below, but rather by the claims and their equivalents.

[0025] 1, the switching device SD includes a housing HS, a movable element ME made of a header HD, a first magnet C1, and a second magnet C2. The switching device SD further includes a printed circuit board PCB fixed to the housing, and a first magnetic sensing element MSE1 and a second magnetic sensing element MSE2 connected to the printed circuit board PCB.

[0026] The movable element ME is slidably mounted within the housing and adapted to move relative to the housing between a rest position and an engaged position, for which purpose the housing HS is provided with a slot in which the movable element is slidably guided.

[0027] The printed circuit board PCB is fixed to the housing and has a top surface on which the first magnetic sensing element MSE1 and the second magnetic sensing element MSE2 are mounted in front.

[0028] The printed circuit board PCB further comprises a microcontroller MCU capable of communicating with an interface of a host computing unit, the host computing unit being operable based on feedback provided by the microcontroller MCU.

[0029] Assume that the first magnetic sensing element MSE1 is well aligned with the first magnet C1, and the second magnetic sensing element MSE2 is well aligned with the second magnet C2. This structure allows the first magnetic sensing element MSE1 and the second magnetic sensing element MSE2 to be excited by the first magnet C1 and the second magnet C2, respectively.

[0030] When the switching device is operated, for example, by a human, the header is pressed in the direction P, i.e., toward the printed circuit board, causing the first magnet C1 and the second magnet C2 to approach the first magnetic sensing element MSE1 and the second magnetic sensing element MSE2, respectively, and, according to magnetic principles, increasing the magnetic flux through the magnetic sensing elements, which changes the state of the switching device when it reaches a threshold value, which means that the state of the switching device is related to the magnitude of the magnetic field.

[0031] In one embodiment, the switching device is part of a button, such as a push button or selector. In all cases, an operator actuates the button (presses or rotates the button), causing the header and magnet to translate toward the magnetic sensing element.

[0032] Referring to FIG. 2, the operating principle of the switching device is shown.

[0033] The first magnet C1 and the second magnet C2 generate a first magnetic field F1 and a second magnetic field F2, respectively, that interact with the first sensing element MSE1 and the second magnetic sensing element MSE2, respectively.

[0034] The first and second magnetic sensors modify their respective output signals S1 and S2 in accordance with the sensed first and second magnetic fields F1 and F2, which are read by the microcontroller MCU and processed to determine whether there is a switching device status or fault condition.

[0035] The switching device implements opposite magnetic polarities between its two redundant input channels, i.e., the first magnet C1 and the second magnet C2. With respect to direction P, the first magnet C1 presents a south magnetic pole "S" above the north magnetic pole, while the second magnet C2 presents a north magnetic pole "N" above the south magnetic pole. This opposite configuration allows the switching device to be robust against external perturbations, since external magnetic perturbations will mostly affect both magnetic sensors with the same polarity.

[0036] Furthermore, because of the opposite polarity configuration, there is a consistent and repeatable pattern for determining whether the switching device has changed state, which cannot be obtained by external perturbations.

[0037] Due to the structure of the switching device, in one embodiment, the first magnetic field F1 generated by the first magnet C1 is assumed to be equal in magnitude to the second magnetic field F2 generated by the second magnet C2, but inverted. This may be the case particularly when the first magnet C1 and the second magnet C2 have the same characteristics. Under normal operating conditions, i.e., without magnetic perturbations, the first output signal S1 and the second output signal S2 should have similar characteristics to the first magnetic field F1 and the second magnetic field F2. Depending on the selected coordinate system, this means that the first output signal S1 should be equal in magnitude to the second output signal S2, but inverted. Therefore, the sum of the first output signal and the second output signal is assumed to be substantially equal to zero.

[0038] In another embodiment, the first magnetic field F1 generated by the first magnet C1 is inverted relative to the second magnetic field F2 generated by the second magnet C2, but the magnitudes are not equal. This may be the case, particularly if the first magnet C1 and the second magnet C2 do not have the same characteristics. Under normal operating conditions, the first output signal S1 and the second output signal S2 should have similar characteristics to the first magnetic field F1 and the second magnetic field F2, which, depending on the selected coordinate system, means that the first output signal S1 must be inverted in magnitude relative to the second output signal S2. Therefore, the sum of the first output signal S1 and the second output signal S2 is assumed to be substantially equal to a predetermined value derived from the difference between the magnitudes of the first and second magnetic fields.

[0039] The output signal may be under different types, and the behavior of the output signal with respect to the corresponding magnetic field may depend on the type of output signal. It is considered that the output signal of the magnetic sensing element must be omni-polar, meaning that the magnetic sensing element can detect and distinguish between north and south poles. In non-limiting examples, the output signal may be under the form of analog output of voltage or current, or PWM and digital output.

[0040] In another embodiment, the first magnetic sensing element MSE1 and the second magnetic sensing element MSE2 may have different calibrations, meaning that for a similar magnetic field, the first output signal S1 and the second output signal S2 may be different but should have similar behavior. In that case, it may be assumed that, taking into account the calibrations of the first magnetic sensing element MSE1 and the second magnetic sensing element MSE2, the sum of the first output signal and the second output signal is approximately equal to a predetermined value derived from the difference between the magnitude of the first magnetic field and the magnitude of the second magnetic field.

[0041] 3a, the output signal is shown in the form of an analog output of voltage as a function of the magnetic field B, where the first magnet C1 and the second magnet C2 have the same properties and the first magnetic sensing element MSE1 and the second magnetic sensing element MSE2 have similar calibrations. The same principle can be applied to different types of outputs.

[0042] For example, when the header HD is not attached to the switching device SD, meaning that there is no magnetic field around the first magnetic sensing element MSE1 and the second magnetic sensing element MSE2, the voltage of the analog output of the first magnetic sensing element MSE1 and the second magnetic sensing element MSE2 is Vcc / 2. In the pole configuration of the first and second magnets of Figure 2, when the header HD is attached and pressed toward P, the second output signal S2 increases toward Vcc and the first output signal S1 decreases toward 0.

[0043] In this example, with an analog output of voltage and an offset of Vcc / 2, a consistency rule is defined whereby the output from the sensor is valid whenever the following statement is always satisfied: S1 + S2 ≒ Vcc V min1 <S1<V max1、 V min2 <S2<V max2

[0044] The minimum value V of the first output signal S1 min1 and the maximum value V of the first output signal S1 max1defines a valid range that includes the allowable values ​​of the first output signal S1. Similarly, the minimum value V of the second output signal S2 min2 and the maximum value V of the second output signal S2 max2 defines a valid region that includes the allowable values ​​of the second output signal S2.

[0045] Referring to FIG. 3b, the behavior of different output signals from the first sensing element MSE1 and the second magnetic sensing element MSE2 is shown.

[0046] As seen in Case 1, when the switching device is open, two opposite but equal magnetic fields are sensed by the first sensing element MSE1 and the second magnetic sensing element MSE2. As seen in Case 2, when the switching device is engaged, both magnetic fields increase as the first magnet and the second magnet approach the first sensing element MSE1 and the second magnetic sensing element MSE2, respectively. For both Case 1 and Case 2, the consistency of both magnetic fields is maintained, allowing the output to be easily determined and considered reliable.

[0047] Cases 3 and 4 do not satisfy two conditions of the consistency rule. Therefore, Cases 3 and 4 are considered to be deviation disturbances. This simple approach of using opposing magnetic fields to manage redundancy in switching devices provides a way to detect and manage external disturbances in an easy and cost-effective manner. Furthermore, this principle can be used to diagnose the integrity of the entire device with a very simple principle, thereby significantly increasing the diagnostic coverage.

[0048] Referring to FIG. 4, a method for verifying a reliable position of a movable element of a switching device SD according to an embodiment of the present invention includes steps S1 to S5.

[0049] In step S1, the movable element made of the header HD, the first magnet C1 and the second magnet C2 is operated, engaged or released, and the movable element moves relative to the housing between a released position and an engaged position.

[0050] In step S2, the first magnetic sensing element MSE1 and the second magnetic sensing element MSE2 detect the first magnetic field F1 and the second magnetic field F2 generated by the first magnet C1 and the second magnet C2, respectively.

[0051] In step S3, the first magnetic sensing element MSE1 and the second magnetic sensing element MSE2 generate a first output signal S1 and a second output signal S2 from the first magnetic field F1 and the second magnetic field F2, respectively.

[0052] In step S4, the microcontroller MCU checks whether the following two conditions of the consistency rule are met: the first output signal falls within a first range of values ​​and the second output signal falls within a second range of values; and if the sum of the first output signal and the second output signal is substantially equal to a predetermined value derived from the difference between the magnitude of the first magnetic field and the magnitude of the second magnetic field; Verify reliable position of moving elements.

[0053] The microcontroller will not operate if at least one of the two conditions is not met. In other words, if the first output signal is outside the first range of values ​​or if the second output signal is outside the second range of values; and / or if the sum of the first output signal and the second output signal is not substantially equal to a predetermined value derived from the difference between the magnitude of the first magnetic field and the magnitude of the second magnetic field; Detecting magnetic perturbations without verifying reliable position of moving elements.

[0054] Generally, the first magnetic field F1 generated by the first magnet C1 is inverted and approximately equal in magnitude to the second magnetic field F2 generated by the second magnet C2. When the first output signal and the second output signal have similar behavior as the first magnetic field and the second magnetic field, the sum of the first output signal and the second output signal is approximately equal to a predetermined value, where the predetermined value is derived from the difference between the magnitude of the first magnetic field and the magnitude of the second magnetic field.

[0055] In step S5, if the microcontroller MCU detects a magnetic perturbation, the microcontroller MCU can trigger an alarm or error that is handled by the control system of the switching device, and the control system decides on the type and status of the switching device. For example, in a critical situation requiring high reliability of the state of the switching device, if a perturbation is detected, the control system can consider it an error.

[0056] Although the present invention has been described with reference to specific embodiments, it is not intended that the invention be limited to the specific forms set forth herein. Rather, the invention is limited only by the appended claims, and other embodiments other than those specifically described above are equally possible within the scope of these appended claims.

[0057] Furthermore, while exemplary embodiments are described above with certain exemplary combinations of components and / or functions, it should be understood that alternative embodiments may be provided with different combinations of components and / or functions without departing from the scope of the present disclosure. Furthermore, it is specifically contemplated that particular features described individually or as part of an embodiment can be combined with other individually described features or parts of other embodiments.

Claims

1. Housing (HS) and a movable element made of a header, a first magnet (C1) and a second magnet (C2) slidably mounted within said housing, said movable element adapted to move relative to said housing between a rest position and an engaged position; a printed circuit board (PCB) comprising a microcontroller and a top surface having mounted thereon a first magnetic sensing element (MSE1) and a second magnetic sensing element (MSE2) positioned to face the first magnet (C1) and the second magnet (C2); the first magnetic sensing element (MSE1) and the second magnetic sensing element (MSE2) are configured to detect a first magnetic field and a second magnetic field generated by the first magnet (C1) and the second magnet (C2), respectively, and the movable element is closer to the first magnetic sensing element (MSE1) and the second magnetic sensing element (MSE2) in the engaged position than in the rest position; the polar configuration of the first magnet (C1) is opposite to the polar configuration of the second magnet (C2), and the first magnetic field generated by the first magnet is reversed in magnitude relative to the second magnetic field generated by the second magnet; the first magnetic sensing element (MSE1) and the second magnetic sensing element (MSE2) are capable of generating first and second output signals from the first and second magnetic fields, respectively; The microcontroller the first output signal is within a first range of values ​​and the second output signal is within a second range of values; and when a sum of the first output signal and the second output signal is substantially equal to a predetermined value derived from the difference between the magnitude of the first magnetic field and the magnitude of the second magnetic field; A reliable position of the moving element can be verified. Switching device.

2. The microcontroller if the first output signal is outside a first range of values ​​or if the second output signal is outside a second range of values; and / or if the sum of the first output signal and the second output signal is not substantially equal to the predetermined value; The switching device of claim 1 capable of detecting magnetic perturbations.

3. The switching device of claim 2 , wherein the microcontroller is capable of triggering an alarm if a magnetic perturbation is detected.

4. A switching device according to any one of claims 1 to 3, wherein the predetermined value is 0 if the first magnet (C1) and the second magnet (C2) have the same properties.

5. 5. The switching device of claim 4, wherein when the switching device is operated, the header is pressed toward the printed circuit board (PCB), causing the first magnet (C1) and the second magnet (C2) to approach the first magnetic sensing element (MSE1) and the second magnetic sensing element (MSE2), respectively, and when a threshold is reached, the switching device increases magnetic flux through the magnetic sensing elements, causing the switching device to change state.

6. 5. The switching device of claim 4, wherein the first magnetic sensing element (MSE1) and the second magnetic sensing element (MSE2) are omnipolar sensors that can distinguish magnetic north from magnetic south poles.

7. 5. The switching device of claim 4, wherein the first magnetic sensing element (MSE1) is aligned with the first magnet (C1) and a first inductor (EM1), and the second magnetic sensing element (MSE2) is aligned with the second magnet (C2) and a second inductor (EM2).

8. 5. The switching device of claim 4, which is part of a push button or a selector.

9. 1. A method for verifying a reliable position of a moving element of a switching device (SD) comprising a housing (HS), the moving element being made of a header, a first magnet (C1) and a second magnet (C2) and slidably mounted within the housing, the moving element being adapted to move relative to the housing between a rest position and an engaged position, the switching device (SD) further comprising a printed circuit board (PCB) comprising a microcontroller and a top surface having mounted on its front side first and second magnetic sensing elements (MSE1) and (MSE2) positioned to face the first and second magnets (C1) and (C2), the method comprising: the first magnetic sensing element (MSE1) and the second magnetic sensing element (MSE2) respectively detect (S2) a first magnetic field and a second magnetic field generated by the first magnet (C1) and the second magnet (C2), respectively, wherein the movable element is closer to the first magnetic sensing element (MSE1) and the second magnetic sensing element (MSE2) in the engaged position than in the rest position; the polar configuration of the first magnet (C1) is opposite to the polar configuration of the second magnet (C2), and the first magnetic field generated by the first magnet is inverted and equal in magnitude to the second magnetic field generated by the second magnet; the first magnetic sensing element (MSE1) and the second magnetic sensing element (MSE2) generate (S3) a first output signal and a second output signal from the first magnetic field and the second magnetic field, respectively; The microcontroller (MCU) the first output signal is within a first range of values ​​and the second output signal is within a second range of values; and when a sum of the first output signal and the second output signal is substantially equal to a predetermined value derived from the difference between the magnitude of the first magnetic field and the magnitude of the second magnetic field; Verifying (S4) the reliable position of the moving element; The method includes:

10. A computer readable medium having embodied thereon a computer program for performing the method for verifying a trusted position of a moving element of a switching device (SD) according to claim 9.

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