Hybrid displacement sensor

Abstract

We provide hybrid displacement sensors. [Solution] The hybrid displacement sensor (100) includes a waveguide (106), a target magnet (110), and a pickup (108). The waveguide includes a longitudinal axis (111), an input end (138), and a reflecting end (134). The target magnet is configured to move along the longitudinal axis with respect to the waveguide. The pickup includes a magnetostrictive detection element (120A) provided adjacent to the input end and a plurality of Hall effect detection elements (120B) distributed along the longitudinal axis.

Description

Technical Field

[0001] Cross - reference to Related Applications This application claims the benefit of and priority to U.S. Provisional Patent Application Serial No. 63 / 727,706, filed on December 4, 2024, the entire content of which is incorporated herein by reference.

[0002] Technical Field Embodiments of the present disclosure generally relate to displacement sensors, and more specifically, to hybrid displacement sensors including magnetostrictive detection elements and Hall effect detection elements.

Background Art

[0003] Magnetostrictive displacement sensors are robust and high - resolution devices, and have been proven useful in a number of measurement and control applications. Magnetostrictive displacement sensors generally include a sensor assembly, sensor electronics, and a target magnet.

[0004] The sensor assembly generally includes a waveguide (e.g., a conductive wire) and a pickup. The target magnet has a variable position along the waveguide corresponding to the position being measured. The sensor electronics includes an excitation generator circuit that generates an excitation signal such as a current pulse transmitted through the waveguide.

[0005] The excitation signal generates a magnetic field around the waveguide that interacts with the magnetic field of the target magnet, causing a magnetostrictive response at the position of the target magnet in the waveguide. The magnetostrictive response takes the form of an acoustic wave having a mechanical pulse component that includes a longitudinal wave corresponding to the compression of the waveguide along its longitudinal axis and a torsional wave corresponding to the torsional strain on the surface of the waveguide with respect to the longitudinal axis.

[0006] The pickup is located at the end of the waveguide and includes a magnetostrictive transducer or sensing element that converts longitudinal or torsional waves into electrical pulses. The electrical pulses act as a signature or index of the wave in the sensor signal output from the sensing element. The sensor signal may be processed, for example, by a sensor electronic circuit to determine the position of a target magnet based on the generation of an excitation signal and the measurement of the propagation time from the detection of the longitudinal or torsional wave index in the sensor signal. [Overview of the project] [Problems that the invention aims to solve]

[0007] Such magnetostrictive displacement sensors are well-suited to providing accurate measurements over the "stroke" distance along the waveguide. However, the stroke distance measurable by conventional magnetostrictive displacement sensors does not include the "null" region at the end of the waveguide. As a result, the length over which the sensor can perform position measurements on a target magnet is shortened by the length of these null regions.

[0008] One reason for introducing a null region at the input end of a waveguide is the response of a highly sensitive pickup located near the input end to the strong magnetic field of the injected excitation signal. Similar to striking a tuning fork, the sensor signal output from the pickup in response to the injected excitation signal oscillates for a predetermined period of time, preventing the detection of an indicator of an electrical pulse corresponding to the magnetostrictive response of a torsional or longitudinal wave in the waveguide. This period of time corresponds to the minimum distance of the target magnet from the input end of the waveguide.

[0009] Another factor influencing the length of the null region at the waveguide input end is the magnetic field of the target magnet that directly interacts with the pickup. Therefore, the null region at the input end generally extends over a distance where the magnitude of the "noise" in the sensor signal resulting from the direct interaction with the target magnet's magnetic field does not interfere with the detection of electrical pulses corresponding to torsional or longitudinal waves.

[0010] As the target magnet approaches the reflective end of the waveguide, the reflection of the magnetostrictive response generated from the reflective end can interfere with the detection of the index corresponding to the position of the target magnet. Therefore, a null region at the reflective end of the waveguide is used to avoid such interference problems.

[0011] Magnetostrictive sensors mitigate some of the causes of null regions by utilizing various conventional techniques. However, even when such techniques are implemented, the null region can still have a total length of more than 5 centimeters, which negatively impacts the useful stroke distance of the magnetostrictive displacement sensor relative to the overall length of the sensor. [Means for solving the problem]

[0012] Embodiments of the present disclosure generally relate to hybrid displacement sensors that include both magnetostrictive detection elements and Hall effect detection elements. One embodiment of the hybrid displacement sensor includes a waveguide, a target magnet, and a pickup. The waveguide includes a longitudinal axis, an input end, and a reflecting end. The target magnet is configured to move along the longitudinal axis with respect to the waveguide. The pickup includes a magnetostrictive detection element provided adjacent to the input end and a plurality of Hall effect detection elements distributed along the longitudinal axis. Additional embodiments of the hybrid displacement sensor include one or more of the embodiments described below.

[0013] According to one aspect, The magnetostrictive detection element is configured to output a first sensor signal having an index of the magnetostrictive response in the waveguide, corresponding to the position of the target magnet in the waveguide. The Hall effect detection element is configured to output one or more second sensor signals corresponding to the position of the target magnet relative to the waveguide.

[0014] According to one embodiment, the hybrid displacement sensor includes an electronic circuit, Electronic circuits are, An excitation generator circuit configured to send a current pulse to the input terminal of a waveguide, The system includes a controller configured to output an estimated position of a target magnet based on one or more of the first sensor signals and / or the second sensor signals.

[0015] According to one aspect, The controller is configured to output an estimated position based on a first sensor signal when the target magnet is located within a central region extending along the longitudinal axis between the input end and the reflecting end. The controller is configured to output an estimated position based on one or more second sensor signals when the target magnet is located within an input null region extending along the longitudinal axis from a position near the input end toward the central region, and / or when the target magnet is located within a reflect null region extending along the longitudinal axis from a position near the reflect end toward the central region.

[0016] In one embodiment, the controller is configured to output an estimated position of a target magnet based on a first sensor signal and one or more second sensor signals if the target magnet is located in an overlapping region between the central region and the input null region and / or between the central region and the reflection null region along the longitudinal axis.

[0017] According to one embodiment, the first sensor signal includes an index of the magnetostrictive response generated based on a current pulse and the magnetic field of the target magnet, when the target magnet is located within the central region.

[0018] According to one aspect, The magnetostrictive detection element includes a sensor magnet and coil, or a piezoelectric material. The relative motion between the magnet and the coil, which responds to the magnetostrictive response, generates a first sensor signal in the coil. The piezoelectric material is configured to generate a first sensor signal in response to a mechanical stress on the piezoelectric material caused by a magnetostrictive response.

[0019] According to one aspect, the Hall effect detection elements are distributed along the input null region of the longitudinal axis and / or the reflection null region of the longitudinal axis.

[0020] According to one aspect, the Hall effect detection elements are distributed along at least a part of the overlapping region of the longitudinal axis.

[0021] According to one aspect, the Hall effect detection elements are each configured to detect the magnitude of the magnetic field in at least two dimensions.

[0022] According to one aspect, the Hall effect detection elements are each configured to detect the magnitude of the magnetic field in at least three dimensions.

[0023] Another embodiment of the hybrid displacement sensor includes a sensor assembly and sensor electronics. The sensor assembly includes a waveguide having a longitudinal axis, an input end, and a reflection end, a target magnet configured to move along the longitudinal axis of the waveguide, and a pickup. The pickup includes a magnetostriction detection element provided adjacent to the input end and a plurality of Hall effect detection elements distributed along the longitudinal axis. The sensor electronics includes a controller configured to output an estimated position of the target magnet based on a first sensor signal generated by the magnetostriction detection element and / or one or more second sensor signals generated by one or more of the Hall effect detection elements. Additional embodiments of the hybrid displacement sensor include one or more of the aspects described below.

[0024] According to one aspect, the sensor electronics includes an excitation generator circuit configured to send a current pulse to the input end of the waveguide.

[0025] According to one aspect, the controller is configured to output an estimated position based on the first sensor signal when the target magnet is provided in a central region extending between the input end and the reflection end along the longitudinal axis, The controller is configured to output an estimated position based on one or more second sensor signals when the target magnet is located within an input null region extending along the longitudinal axis from a position near the input end toward the central region, and / or when the target magnet is located within a reflect null region extending along the longitudinal axis from a position near the reflect end toward the central region.

[0026] In one embodiment, the controller is configured to output an estimated position of a target magnet based on a first sensor signal and one or more second sensor signals if the target magnet is located in an overlapping region between the central region and the input null region and / or between the central region and the reflection null region along the longitudinal axis.

[0027] In one embodiment, the Hall effect detection elements are distributed along the input null region and / or the reflection null region along the longitudinal axis.

[0028] According to one embodiment, the Hall effect detection elements are distributed along at least a portion of the overlapping region of the longitudinal axis.

[0029] According to one embodiment of a method for operating a hybrid displacement sensor, the hybrid displacement sensor includes a sensor assembly and sensor electronic circuitry. The sensor assembly includes a waveguide having a longitudinal axis, an input end, and a reflecting end, a target magnet configured to move along the longitudinal axis with respect to the waveguide, and a pickup. The pickup includes a magnetostrictive detection element provided adjacent to the input terminal and a plurality of Hall effect detection elements distributed along the longitudinal axis. The sensor electronic circuit includes an excitation generator circuit and a controller. This method, The process involves sending a current pulse to the input terminal of a waveguide using an excitation generator, and generating a first sensor signal based on the current pulse using a magnetostrictive detection element. To generate one or more second sensor signals using a Hall effect detection element. This includes performing at least one of the following: The method also includes using a controller to output an estimated position of the target magnet based on a first sensor signal and at least one of one or more second sensor signals. Additional embodiments of this method include one or more of the embodiments described below.

[0030] According to one embodiment, outputting the estimated position of the target magnet is: When the target magnet is located within a central region extending between the input end and the reflection end along the longitudinal axis, the estimated position of the target magnet is output based on the first sensor signal. The system includes outputting an estimated position of the target magnet based on one or more second sensor signals when the target magnet is located within an input null region extending along the longitudinal axis from a position near the input end toward the central region, and / or when the target magnet is located within a reflect null region extending along the longitudinal axis from a position near the reflect end toward the central region. Hall effect elements are distributed along the input null region and / or reflection null region along the longitudinal axis.

[0031] According to one embodiment, outputting the estimated position of a target magnet includes outputting the estimated position of the target magnet based on a first sensor signal and one or more second sensor signals when the target magnet is located in an overlapping region between the central region and the input null region and / or between the central region and the reflection null region along the longitudinal axis.

[0032] This summary is provided in a simplified form to introduce the selection of concepts, which are further described in embodiments for carrying out the inventions described below. This summary is not intended to identify any key or essential features of the subject matter, nor is it intended to be used to help determine the scope of the subject matter. The subject matter described in the claims is not limited to embodiments that solve any or all of the defects described in the background. [Brief explanation of the drawing]

[0033] [Figure 1] This is a schematic diagram of one embodiment of the hybrid displacement sensor according to the present disclosure. [Figure 2] This is a simplified circuit diagram of one embodiment of a hybrid displacement sensor according to the present disclosure. [Figure 3A] This is an isometric view of an embodiment of a pickup having a magnetostrictive detection element according to the present disclosure. [Figure 3B] This is an isometric view of an embodiment of a pickup having a magnetostrictive detection element according to the present disclosure. [Figure 3C] This is an isometric view of an embodiment of a pickup having a magnetostrictive detection element according to the present disclosure. [Figure 3D] This is an isometric view of an embodiment of a pickup having a magnetostrictive detection element according to the present disclosure. [Figure 4] This is a simplified side view of one embodiment of a hybrid displacement sensor according to the present disclosure. [Figure 5] This is a simplified diagram of one embodiment of the controller according to the present disclosure. [Modes for carrying out the invention]

[0034] Embodiments of the present disclosure are described more thoroughly below with reference to the accompanying drawings. Components identified by the same or similar reference numerals indicate the same or similar components. However, various embodiments of the present disclosure may be carried out in numerous different forms and should not be construed as being limited to the specific embodiments described herein. Rather, the embodiments are described in a manner that makes the present disclosure detailed and complete and that fully conveys the scope of the embodiments to those skilled in the art.

[0035] Figures 1 and 2 are schematic and simplified circuit diagrams, respectively, of an embodiment of the hybrid displacement sensor 100 according to the present disclosure. The displacement sensor 100 includes a sensor assembly 102 and a sensor electronic circuit 104. The sensor assembly 102 includes a magnetorheological conductor called a waveguide 106 and a pickup 108.

[0036] At least one target magnet 110 is provided near the waveguide 106 and has an adjustable position 112 along the axis 111 of the waveguide 106, as indicated by the arrow 113. The target magnet 110 may be in the form of a bar magnet provided along the waveguide 106, a ring magnet surrounding the waveguide 106, or any other suitable form.

[0037] The displacement sensor 100 is generally configured to measure the position 112 of a target magnet 110 along a waveguide 106 with respect to a reference position 114, using one or more detection elements 120 of a pickup 108. In one embodiment, the detection elements 120 include a magnetostrictive detection element 120A configured to output a sensor signal 122A, and a plurality of Hall effect detection elements 120B configured to output one or more sensor signals 122B (hereinafter referred to as sensor signal 122B), as shown in Figure 2. A signal conditioner 124 of the pickup 108 may be used, according to the prior art, to isolate the detection elements 120 from electrical interference and to adjust (e.g., amplify, rectify, filter, etc.) one or more sensor signals 122.

[0038] The sensor electronic circuit 104 includes a controller 126, which is configured to output an estimated value 128 of the target magnet position 112 based on a sensor signal 122A, a sensor signal 122B, or a combination of sensor signals 122A and 122B, depending on the operating mode of the displacement sensor 100. Thus, the position estimate 128 may correspond to a position estimate 128A based on a sensor signal 122A output by a magnetostrictive detection element 120A, a position estimate 128B based on a sensor signal 122B output by a Hall effect detection element 120B, and / or a combination of position estimates 128A and 128B, as shown in Figure 2.

[0039] The position estimate 128A may be determined by the controller 126 using prior art. For example, the sensor electronic circuit 104 includes an excitation generator circuit 130 connected to the waveguide 106. As shown in Figure 1, a closed electrical circuit may be formed by the excitation generator circuit 130, the waveguide 106, and a return wire 132 connecting the reflecting end 134 of the waveguide 106 to the excitation generator circuit 130. The controller 126 generates an excitation signal (e.g., a current pulse) 136 using the excitation generator circuit 130, and the excitation signal 136 is sent to the input end 138 of the waveguide 106. An amplifier 140 (Figure 2) of the sensor electronic circuit 104 may be used to amplify the current pulse 136 before applying it to the waveguide 106.

[0040] The transmission of current pulses 126 through waveguide 106 generates a magnetic field 141, which interacts with the magnetic field 142 of magnet 110 to generate a mechanical magnetostrictive response (e.g., sound wave) 144 in waveguide 106. This includes longitudinal waves 144A (e.g., longitudinal compression) and torsional waves 144B (e.g., torsional strain), as shown in Figure 1.

[0041] The magnetostrictive response 144 propagates along the waveguide 106 from both sides of the magnet 110. For example, portions of the magnetostrictive response 144 may propagate along the waveguide 106 from position 112 of the magnet 110 toward end 134, and possibly to a damper (not shown) that reduces or eliminates the backpropagation of the acoustic wave 144 through the waveguide 106. Furthermore, portions of the magnetostrictive response 144 propagate from position 112 of the magnet 110 toward input end 138, where a magnetostrictive detection element 120A is used to detect the magnetostrictive response 144, such as a longitudinal wave 144A and / or a torsional wave 144B, and to output a sensor signal 122A containing one or more indices of the magnetostrictive response 144. One or more indices may include, for example, transient changes or pulses in the magnitude of the signal 122A.

[0042] The exemplary sensor electronic circuit 104 may include a signal conditioner 146 that processes the sensor signal 122A (e.g., amplify, filter, etc.) before sampling the signal 122A using an analog-to-digital converter 148 to generate a sample 122A'. Sample 122A' is processed by a controller 126 to identify an index. The controller 126 determines a time period from the time when the current pulse 136 is generated to the time corresponding to the index of the magnetostrictive response 144 in signal 122A or sample 122A'. The time period may be measured by the controller 126 based on a clock signal issued by a clock generator 149, according to the prior art. Based on the determined time period, the controller 126 generates an estimate 128A of the target magnet position 112. Depending on the operating mode of the displacement sensor 100, the controller 126 may output the position estimate 128A as the final position estimate 128, as described later.

[0043] Figures 3A to 3D are isometric views of embodiments of a pickup 108 having a magnetostrictive detection element 120A according to the present disclosure. The exemplary detection element 120A in Figure 3A includes a coil 150, which is attached to a waveguide 106, for example, via a rigid member 152. A bias or sensor magnet 154 is placed near the coil 150 and generates a magnetic field surrounding the coil 150. When the magnetostrictive response 144 (e.g., a longitudinal or torsional wave) propagating through the waveguide 106 reaches the member 152, it causes distortion of the member 152, which, according to the Villari effect, causes a change in the magnetization of the member 152. The variable permeability of the member 152, combined with the magnetic field of the bias magnet 154, results in fluctuations in the magnetic flux passing through the coil 150. This drives the current pulse index of the magnetostrictive response 144 in the sensor signal 122A. As described above, the sensor signal 122A from coil 150 may be processed by signal conditioner 146 before being sent to controller 126 (Figure 2).

[0044] One alternative to this configuration is to form member 152 from the magnetic material that forms the sensor magnet and support the coil 150 in such a way that the magnetic member 152 can move relative to the coil 150. Thus, when the magnetic member 152 vibrates in response to the magnetostrictive response 144, the movement of the magnetic field relative to the coil 150 induces a corresponding current pulse index in the sensor signal 122A from the coil 150.

[0045] The detection element 120A may include a conductive coil 156 wound around the waveguide 106, as shown in Figure 3B, or the conductive coil 156 may be arranged in a plane generally perpendicular to the waveguide 106, as shown in Figure 3C. In each case, the magnetostrictive response 144 propagating through the waveguide 106 induces a current pulse or index in the sensor signal 122A propagating through the coil 156.

[0046] The exemplary detection element 120A shown in Figure 3D comprises a piezoelectric material 158 connected to a waveguide 106, configured to physically strain in response to a magnetostrictive response 144. The strain in the piezoelectric material 158 generates a current pulse in the sensor signal 122A, which forms an indicator of the response 144. The piezoelectric material 158 may be exposed to the magnetostrictive response 144, for example, via a piezoelectric material 158A connected to the waveguide side via a rigid member 159, or via a piezoelectric material 158B connected to or following the waveguide of the waveguide.

[0047] Figure 4 is a simplified side view of one embodiment of the hybrid displacement sensor 100 according to the present disclosure. In some embodiments, the position estimate 128 is based solely on the position estimate 128A determined using the magnetostrictive detection element 120A when the target magnet position 112 is in the central region 160 of the waveguide 106, as in the prior art described above. The central region may extend from position 112A to position 112B. As described above, the length of the central region 160 is generally limited by the input null region 162 at the input end 138 and the reflection null region 163 at the reflection end 134 of the waveguide 106. Thus, conventional magnetostrictive displacement sensors have a stroke length limited by the null regions 162 and 163.

[0048] In some embodiments, the Hall effect detection element 120B is distributed along the axis 111 adjacent to the waveguide 106 across the input null region 162 and / or the reflected null region 163, as shown in Figure 4, and is used to overcome the stroke distance limitations of the magnetostrictive detection element 120A by detecting the position 112 of the target magnet 110 within the null region 162 and / or 163. As a result, the hybrid sensor 100 has a stroke distance that is the range in which the position 112 of the target magnet 110 can be detected, which is increased compared to a conventional magnetostrictive displacement sensor that uses only a magnetostrictive detection element.

[0049] As shown in Figure 4, the magnetostrictive detection element 120A is located adjacent to the input end 138 of the waveguide 106, for example, within a range of about 5 millimeters, e.g., 4 to 6 millimeters, from the input end 138. The input null region 162 generally includes a region along the axis 111 where, for example, interference caused by the injected excitation signal 136 and / or the magnetic field 141 of the target magnet 110 prevents the magnetostrictive detection element 120A from accurately detecting the position 112 of the target magnet 110. Thus, the null region 162 generally extends from a position 112C near the input end 138 toward the central region 160, e.g., to position 112A, or from position 112A toward a position 112D offset toward the input end 138, as shown in Figure 4. In one embodiment, the null region 162 is about 3 to 4 centimeters.

[0050] The reflective null region 163 generally includes a region along the axis 111 where, for example, interference caused by the reflection of the magnetostrictive response 144 at the reflective end 134 or other interference prevents the magnetostrictive detection element 120A from accurately detecting the position 112 of the target magnet 110. Thus, the null region 163 generally extends from a position 112E near the reflective end 134 toward the central region 160, as shown in Figure 4, and extends, for example, to position 112B, or from position 112B toward a position 112F offset toward the reflective end 134. In one embodiment, the null region 163 is about 3 to 4 centimeters.

[0051] The Hall effect detection elements 120B may include a first group 164 of elements 120B in the input null region 162 of the waveguide 106, and / or a second group 166 of elements 120B in the reflection null region 163 of the waveguide 106, as shown in Figure 4. The number of detection elements 120B in each group 164 and 166 may vary depending on the length of the corresponding null regions 162 and 163. In one embodiment, each group 164 and group 166 includes, for example, three or more detection elements 120B, or about one detection element 120B per centimeter of the null region.

[0052] The Hall effect detection element 120B may be a conventional device that includes one or more Hall elements that generate a voltage proportional to the axial component of the applied magnetic field based on the known Hall effect. In one embodiment, each detection element 120B includes two or three Hall elements for detecting the magnitude of the applied magnetic field in mutually orthogonal directions, such as two directions (X-axis and Y-axis) or three different directions (X-axis, Y-axis, and Z-axis). An example of a suitable Hall effect detection element 120B is the Hall effect sensor TMAG5273 manufactured by Texas Instruments, which measures the magnetic field of an applied magnetic field in three orthogonal dimensions.

[0053] Various fixed magnetic fields of the sensor 100, such as those from the bias magnet 154 (Figure 3A) of the detection element 120A and / or other magnetic components, can affect the output from the Hall effect detection element 120B. If the detection element 120B utilizes a unidirectional Hall element, only the magnitude of the applied magnetic field is detected. As a result, the precise direction of the magnetic field cannot be determined. This may limit the accuracy and robustness of position measurements obtained using the sensor signal 122B output from the detection element 120B.

[0054] The use of a Hall effect detection element 120B configured to detect the applied magnetic field in two or three dimensions allows the detection element 120 to establish the magnitude and direction of the applied magnetic field. In some embodiments, if the target magnet 110 is not present, a trimming procedure may be performed on the hybrid displacement sensor 100 to establish a set of magnetic field amplitude values ​​in the X, Y, and / or Z axes with respect to a fixed magnetic field generated by various components of the sensor 100 (e.g., bias magnet 154). This set of trimmed values ​​may then be used to compensate for the magnetic field amplitude measurements obtained by the Hall effect detection element 120 during the displacement detection operation by the hybrid sensor 100 to improve the detection of the target magnet position 112.

[0055] The value of the sensor signal 122B from the Hall effect detection element 120B is established, for example, using prior art, for different positions 112 of the target magnet 110 along, for example, region 160 or 162, and stored in the memory of the hybrid sensor 100, such as the memory of the controller 126. The value may be stored as a lookup table, as an expression, or by any other suitable conventional method. During displacement detection, the controller 126 determines the corresponding position 112 of the target magnet 110 by comparing the value represented by the sensor signal 122B with the stored value.

[0056] In some embodiments, the controller 126 may determine the position estimate 128 of the target magnet 110 based solely on the position estimate 128A determined using the magnetostrictive detection element 120A when the target magnet position 112 is inside the central region 160, based solely on the position estimate 128B determined using group 164 of the Hall effect detection element 120B when the target magnet position 112 is inside the input null region 160, and based solely on the position estimate 128B determined using group 166 of the Hall effect detection element 120B when the target magnet position 112 is inside the reflection null region 163.

[0057] An initial determination of whether the target magnet position 112 lies within the central null region 160, the input null region 162, or the reflected null region 163 may be made by the controller 126 based on one or both of the sensor signals 122A and 122B. In one embodiment, the controller 126 first processes the sensor signal 122B to determine whether one or more of the Hall effect detection elements 120B have detected the presence of the magnetic field 141 of the target magnet 110. If the Hall effect detection elements 120B do not detect the presence of the magnetic field 141 (e.g., null signal 122B) indicating that the target magnet position 112 lies within the central region 160, the controller 126 controls the excitation generator 130 to generate an excitation signal 136, determines a position estimate 128A based on the sensor signal 122A of the magnetostrictive detection element 120A, and generates a position estimate 128 based solely on the position estimate 128A.

[0058] If the sensor signal 122B indicates the presence of the target magnet 110 in the input null region 162 or the reflected null region 163, for example, by the amplitude and / or direction of the detected magnetic field satisfying a predefined threshold requirement, the controller 126 determines the position estimate 128B using the sensor signal 122B from the Hall effect detection element 120B in the corresponding group 164 or 166, and generates the position estimate 128 based solely on the position estimate 128B.

[0059] Some embodiments of this disclosure overcome problems that may occur at the intersection between the central region 160 and the input null region 162, and / or between the central region 160 and the reflected null region 163, such as abrupt jumps in the position estimate 128. In some embodiments, the overlapping region 170 may be specified between the central region 160 and the input null region 162, for example, from position 112A to position 112D, as shown, for example, in Figure 4. Similarly, the overlapping region 172 may be specified between the central region 160 and the reflected null region 163, for example, from position 112B to position 112F. Group 164 of Hall effect detection elements 120B may extend partially or completely into the overlapping region 170, and group 166 of Hall effect detection elements 120B may extend partially or completely into the overlapping region 172. In some embodiments, the overlapping region 170 may extend for a length of about 5 to 10 millimeters, and the overlapping region 172 may extend for a length of about 5 to 10 millimeters.

[0060] In one embodiment, if the target magnet 110 is inside the overlapping region 170 or 172, the controller 126 generates a position estimate 128 based on both position estimates 128A and 128B using the corresponding group 164 or 166 of the Hall effect detection element 120B. The controller 126 may first determine, based on the sensor signal 122B, that the target magnet 110 is inside one of the overlapping regions 170 and 172, for example, if the amplitude and / or direction of the magnetic field detected using group 164 or group 166 of the Hall effect detection element 120B indicates a position 112 inside one of the regions 170 or 172.

[0064] If the controller 126 determines that the target magnet position 112 is inside the region 170 or 172, the controller 126 generates a position estimate 128B based on the sensor signal 122B of the corresponding group 164 or 166. The controller 126 also generates a position estimate 128A by sending an excitation signal 136 via the waveguide 106 using the excitation generator 130 and processing the sensor signal 122A, as described above.

[0061] Next, a position estimate 128 is determined based on position estimates 128A and 128B. In one embodiment, weighting is applied to position estimates 128A and 128B, and the position estimate 128 is determined using the average of the weighted estimates, which is then output by the controller 126. When the target magnet 110 moves outward from a position closer to the central region 160 toward the corresponding input null region 162 or reflection null region 163, the weighting applied to position estimate 128A is decreased, while the weighting applied to position estimate 128B is increased. Similarly, when the target magnet 110 moves toward the central region 160 from the input null region 162 or reflection null region 163, the weighting applied to position estimate 128 is increased, while the weighting applied to position estimate 128B is decreased.

[0062] In one embodiment, the weighting applied to the position estimates 128A and 128B is based on the initial position estimate 128B determined using the sensor signal 122B. Thus, in addition to determining whether the target magnet 110 is inside one of the overlapping regions 170 and 172, the controller 126 may assign weighting using the position estimate 128B.

[0063] The weighting generally operates to ensure a smooth transition of the position estimate 128 from a case where the position estimate 128 is based solely on the sensor signal 122A generated by the magnetostrictive detection element 120A, such as when the position 112 of the target magnet 110 is inside the central region, to a case where the position estimate 128 is based solely on the sensor signal 122B generated by the Hall effect detection element 120B in the input null region 162 or the reflection null region 163. In one embodiment, the weighting transitions from a state where the position estimate 128A is 0% applied and the position estimate 128B is 100% applied when the target magnet 110 is estimated to be at position 112D or position 112F, to a state where the position estimate 128A is 100% applied and the position estimate 128B is 0% applied when the target magnet 110 is estimated to be at position 112A or 112B.

[0064] An additional embodiment relates to a method for using the hybrid displacement sensor 100. In one embodiment, the hybrid displacement sensor 100 includes a sensor assembly comprising a sensor electronic circuit 104, a waveguide 106, a target magnet 110, and a pickup 108, formed according to one or more embodiments described above. The waveguide 106 includes a longitudinal axis 111, an input end 138, and a reflecting end 134, as shown in Figure 4. The target magnet 110 is configured to move along the longitudinal axis 111 with respect to the waveguide 106. The pickup includes a magnetostrictive detection element 120A and a plurality of Hall effect detection elements 120B distributed along the axis 111. The sensor electronic circuit includes an excitation generator 130 and a controller 126.

[0065] In one embodiment of this method, a current pulse 136 is sent to the input terminal 138 of the waveguide 106 using an excitation generator 130, and a sensor signal 122A is generated based on the current pulse 136 using a magnetostrictive detection element 120A, and / or one or more sensor signals 122B are generated using a Hall effect detection element 120B. The controller 126 outputs a position estimate 128 based on the sensor signals 122A and / or sensor signals 122B according to the embodiments described above. For example, if the target magnet 110 is located within a central region 160 extending between the input terminal 138 and the reflection terminal 134 along the longitudinal axis 111, the position estimate 128 may be based on a position estimate 128A determined using the sensor signal 122A. If the target magnet 110 is located within an input null region 162 or a reflection null region 163, the position estimate 128 may be based on a position estimate 128B determined using the sensor signal 122B. Furthermore, if the target magnet is in the overlapping region 170 between the central region 160 and the input null region 162, or in the overlapping region 172 between the central region 160 and the reflection null region 163, the position estimate 128 may be based on both position estimates 128A and 128B.

[0066] Figure 5 is a simplified diagram of one embodiment of a controller 126 according to the present disclosure. The exemplary controller 126 may include one or more processors 180 and memory 182. This may be local memory or memory accessible to the controller 126. One or more processors 180 are configured to perform various functions described herein in response to the execution of instructions contained in memory 182, for example.

[0067] One or more processors 180 may be components of one or more computer-based systems and may include one or more control circuits, a microprocessor-based engine control system, and / or one or more programmable hardware components such as a field-programmable gate array (FPGA). Memory 182 represents a computer-readable medium eligible as subject matter of any suitable patent and does not include transient waves or signals. Embodiments of memory 182 include conventional data storage devices such as hard disks, CD-ROMs, optical storage devices, magnetic storage devices, and / or other suitable data storage devices or computer-readable media.

[0068] The controller 126 may include circuits 184 used by one or more processors 180 for receiving input signals 186 (e.g., sensor signals, clock signals 122 from clock generator 149, etc.), issuing control signals 188 (e.g., control signals to excitation generator 130, etc.), and / or communicating data 190 (e.g., position estimates 128, etc.) in response to executing instructions stored in memory 182 by one or more processors 180.

[0069] While embodiments of this disclosure have been described with reference to preferred embodiments, those skilled in the art will recognize that the form and details may be modified without departing from the spirit and scope of this disclosure.

[0070] The functions described herein may be performed by a single controller or processor, multiple controllers or processors, or at least one controller or processor. Where, as used herein, one or more functions are described as being performed by one controller (e.g., controller 126), one or more controllers, at least one controller, one processor (e.g., a specific processor), one or more processors, or at least one processor, embodiments include, unless otherwise specified, the execution of one or more functions by a single controller or processor, or by multiple controllers or processors, in response to the execution of program instructions stored in a non-temporary computer-readable medium. Furthermore, where, as used herein, multiple functions are performed by at least one controller or processor, all of the functions may be performed by a single controller or processor, or some functions may be performed by one controller or one processor, and other functions may be performed by another controller or processor. Thus, the execution of one or more functions by one controller or at least one controller or processor does not require that all of the functions be performed by each of the multiple controllers or multiple processors, or by only one of the multiple controllers or multiple processors.

Claims

1. A hybrid displacement sensor (100) including a sensor assembly (102), A waveguide (106) having a longitudinal axis (111), an input end (138), and a reflection end (134), A target magnet (110) configured to move along the longitudinal axis of the waveguide, Equipped with a pickup (108), The above pickups are A magnetostrictive detection element (120A) is provided adjacent to the above input terminal, It comprises a plurality of Hall effect detection elements (120B) distributed along the longitudinal axis described above. Hybrid displacement sensor.

2. The magnetostrictive detection element is configured to output a first sensor signal (122A) having an index of the magnetostrictive response in the waveguide, corresponding to the position of the target magnet in the waveguide. The Hall effect detection element described above is configured to output one or more second sensor signals (122B) corresponding to the position of the target magnet with respect to the waveguide. The hybrid displacement sensor according to claim 1.

3. The above hybrid displacement sensor is An excitation generator circuit (130) configured to send a current pulse (136) to the input terminal of the waveguide, The sensor electronic circuit (104) includes a controller (126) configured to output an estimated position (128) of the target magnet based on one or more of the first sensor signals and / or the second sensor signals, In one embodiment, The controller is configured to output the estimated position based on the first sensor signal when the target magnet is located within a central region (160) extending between the input end and the reflecting end along the longitudinal axis. The controller is configured to output the estimated position based on one or more second sensor signals when the target magnet is located within an input null region (162) extending from the vicinity of the input end toward the central region along the longitudinal axis, and / or when the target magnet is located within a reflecting null region (163) extending from the vicinity of the reflecting end toward the central region along the longitudinal axis. In further embodiments, The controller described above is configured to output an estimated position of the target magnet based on the first sensor signal and one or more second sensor signals when the target magnet is located in an overlapping region (170, 172) between the central region and the input null region and / or between the central region and the reflection null region along the longitudinal axis. The hybrid displacement sensor according to claim 1 or 2.

4. The first sensor signal described above includes an index of the magnetostrictive response generated based on the current pulse and the magnetic field of the target magnet when the target magnet is located within the central region. In one embodiment, The above magnetostrictive detection element comprises a sensor magnet (152, 154) and a coil (150), or a piezoelectric material (158). The relative motion between the magnet and the coil in response to the magnetostrictive response generates the first sensor signal in the coil. The piezoelectric material (158) is configured to generate the first sensor signal in response to the mechanical stress on the piezoelectric material caused by the magnetostrictive response, and / or The Hall effect detection elements described above are distributed along the input null region and / or the reflection null region along the longitudinal axis. The hybrid displacement sensor according to claim 2 or 3.

5. The Hall effect detection elements described above are distributed along at least a portion of the overlapping region of the longitudinal axis, The hybrid displacement sensor according to claim 4.

6. Each of the above Hall effect detection elements is configured to detect the magnitude of the magnetic field in at least two dimensions. The hybrid displacement sensor according to claim 4.

7. Each of the above Hall effect detection elements is configured to detect the magnitude of the magnetic field in at least three dimensions. The hybrid displacement sensor according to claim 4.

8. A hybrid displacement sensor (100) comprising a sensor assembly (102) and a sensor electronic circuit (104), The above sensor assembly (102) is A waveguide (106) having a longitudinal axis (111), an input end (138), and a reflection end (134), A target magnet (110) configured to move along the longitudinal axis of the waveguide, Equipped with a pickup (108), The above pickup (108) is, A magnetostrictive detection element (120A) is provided adjacent to the above input terminal, It comprises a plurality of Hall effect detection elements (120B) distributed along the longitudinal axis described above, The sensor electronic circuit (104) includes a controller (126) configured to output the estimated position (128) of the target magnet based on at least one of a first sensor signal (122A) generated by the magnetostrictive detection element and one or more second sensor signals (122B) generated by one or more of the Hall effect detection elements. Hybrid displacement sensor.

9. The above sensor electronic circuit includes an excitation generator (130) circuit configured to send a current pulse (136) to the input terminal of the waveguide. The hybrid displacement sensor according to claim 8.

10. The controller is configured to output the estimated position based on the first sensor signal when the target magnet is located within a central region (160) extending between the input end and the reflecting end along the longitudinal axis. The controller is configured to output the estimated position based on one or more second sensor signals when the target magnet is located within an input null region (162) extending from the vicinity of the input end toward the central region along the longitudinal axis, and / or when the target magnet is located within a reflecting null region (163) extending from the vicinity of the reflecting end toward the central region along the longitudinal axis. In one embodiment, The controller described above is configured to output an estimated position of the target magnet based on the first sensor signal and one or more second sensor signals when the target magnet is located in an overlapping region (170, 172) between the central region and the input null region and / or between the central region and the reflection null region along the longitudinal axis. The hybrid displacement sensor according to claim 8.

11. The Hall effect detection elements described above are distributed along the input null region and / or the reflection null region along the longitudinal axis. The hybrid displacement sensor according to claim 10.

12. The Hall effect detection elements described above are distributed along at least a portion of the overlapping region of the longitudinal axis, The hybrid displacement sensor according to claim 11.

13. A method for operating a hybrid displacement sensor (100), The above hybrid displacement sensor (100) comprises a sensor assembly (102) and a sensor electronic circuit (104), The above sensor assembly (102) is A waveguide (106) having a longitudinal axis (111), an input end (138), and a reflection end (134), A target magnet (110) configured to move along the longitudinal axis of the waveguide, Equipped with a pickup (108), The above pickups are A magnetostrictive detection element (120A) is provided adjacent to the above input terminal, It comprises a plurality of Hall effect detection elements (120B) distributed along the longitudinal axis described above, The above sensor electronic circuit (104) includes an excitation generator circuit (130) and a controller (126). The above method, The excitation generator is used to send a current pulse (136) to the input terminal of the waveguide, and the magnetostrictive detection element is used to generate a first sensor signal (122A) based on the current pulse. The above Hall effect detection element is used to generate one or more second sensor signals (122B) and Perform at least one of the following, The above controller is used to output an estimated position (128) of the target magnet based on the first sensor signal and at least one of the one or more second sensor signals. method.

14. Outputting the estimated position of the target magnet mentioned above means When the target magnet is located within a central region (160) extending between the input end and the reflecting end along the longitudinal axis, the estimated position of the target magnet is output based on the first sensor signal. The system includes outputting an estimated position of the target magnet based on one or more second sensor signals when the target magnet is located within an input null region (162) extending from the vicinity of the input end toward the central region along the longitudinal axis, and / or when the target magnet is located within a reflecting null region (163) extending from the vicinity of the reflecting end toward the central region along the longitudinal axis, The Hall effect detection elements described above are distributed along the input null region and / or reflection null region along the longitudinal axis, The method according to claim 13.

15. Outputting the estimated position of the target magnet includes, if the target magnet is located in an overlapping region (170, 172) between the central region and the input null region and / or between the central region and the reflection null region along the longitudinal axis, outputting the estimated position of the target magnet based on the first sensor signal and one or more second sensor signals. The method according to claim 14.

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