Waveguide for a magnetic sensor for measuring position with propagation speed compensation

Abstract

To provide waveguide sensors and position sensing systems.SOLUTION: In some embodiments, a position sensing system may include a waveguide configured to receive and transmit a pulse, and a magnet moveable relative to the waveguide. The waveguide may include a first core layer, a second core layer, a magnetic layer between the first and second core layers, and a conductive winding around the first core layer, the second core layer and the magnetic layer. The position sensing system may further include a first substrate layer above the conductive winding and a second substrate layer below the conductive winding.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] SUMMARY OF THE DISCLOSURE Embodiments of the present disclosure relate generally to waveguide-based position sensors, and more particularly to pulsed waveguide including PCB-based stacks. [Background technology]

[0002] A conventional position measuring device 100 is shown in FIG. 1. The system 1 includes a sensor 10, a pulse generator 20, and a signal receiver 24. The sensor 10 includes a waveguide 12 and a magnet 14. Typically, the magnet 14 is attached to a movable object. In operation, the pulse generator 20 generates a pulse 21 that is communicated to the waveguide 12. The magnet 14 creates an impedance discontinuity 11 in a region of the waveguide 12 proximate to the magnet 14. A reflection of the pulse 21 is reflected from the point of the impedance discontinuity 11, generating a reflected pulse 23. The signal receiver 24 receives the pulse 21 and the reflected pulse 23. The position of the magnet 14 relative to the waveguide 12 can be determined based on the timing of the pulse 21 relative to the reflected pulse 23. More specifically, the difference between the time the pulse 21 is received and the time the reflected pulse 23 is received can be used to determine the position of the magnet 14.

[0003] However, current manufacturing methods for pulsed waveguides require complex process steps, which require high capital investment, strict manufacturing process control, and direct worker involvement, often resulting in poor quality consistency.

[0004] The present disclosure is provided with respect to the above. Summary of the Invention

[0005] In some embodiments, the position detection system may include a waveguide that receives and transmits pulses and a magnet that is movable relative to the waveguide. The waveguide may include a first core layer and a second core layer, a magnetic layer between the first core layer and the second core layer, and a conductive winding around the first core layer, the second core layer, and the magnetic layer. The position detection system may further include a first substrate layer above the winding and a second substrate layer below the winding.

[0006] In some embodiments, the position detection system may include a waveguide for receiving and transmitting pulses, the waveguide configured as a stack of layers, and a magnet movable relative to the waveguide. The waveguide stack of layers may include a first core layer and a second core layer, a magnetic layer between the first core layer and the second core layer, and a conductive winding around the first core layer, the second core layer, and the magnetic layer. The position detection system may further include a first substrate layer above the winding and a second substrate layer below the winding.

[0007] In some embodiments, the waveguide for receiving and transmitting pulses may include a first core layer, a second core layer, and a magnetic layer between the first and second core layers, the magnetic layer being embedded in an insulating material. The waveguide may further include a conductive winding disposed around the first core layer, the second core layer, and the magnetic layer, a first substrate layer disposed above the winding, and a second substrate layer disposed below the winding. [Brief description of the drawings]

[0008] The accompanying drawings illustrate exemplary techniques of the present disclosure including practical applications of its principles.

[0009] [Figure 1] FIG. 1 shows a block diagram of a prior art location detection system.

[0010] [Diagram 2] FIG. 1 is a block diagram illustrating a location detection system according to an embodiment of the present disclosure.

[0011] [Diagram 3] 3 is a block diagram illustrating a portion of the location detection system of FIG. 2 in greater detail, according to an embodiment of the present disclosure.

[0012] [Figure 4A] FIG. 2 is a top view of a waveguide of a position sensing system according to an embodiment of the present disclosure. [Figure 4B] FIG. 2 is a top view of a waveguide of a position sensing system according to an embodiment of the present disclosure. [Figure 4C] FIG. 2 is a top view of a waveguide of a position sensing system according to an embodiment of the present disclosure.

[0013] [Diagram 5] 5 is a cross-sectional view of a waveguide layer stack taken along section line 5-5 of FIG. 4A according to an embodiment of the present disclosure.

[0014] [Figure 6] FIG. 2 illustrates a close-up view of selected layers of a waveguide according to an embodiment of the present disclosure.

[0015] [Figure 7A] 1A-1D illustrate various waveguide configurations according to embodiments of the present disclosure. [Figure 7B] 1A-1D illustrate various waveguide configurations according to embodiments of the present disclosure. [Figure 7C] 1A-1D illustrate various waveguide configurations according to embodiments of the present disclosure.

[0016] The figures are not necessarily to scale. The figures are merely diagrammatic representations and are not intended to portray specific parameters of the present disclosure. The figures are intended to depict exemplary embodiments of the present disclosure and therefore should not be considered limiting in scope. In the figures, like numbers represent like elements.

[0017] Additionally, certain elements in some of the figures may be omitted or not drawn to scale for clarity of illustration. The cross-sectional views may be in the form of a "slice" or "myoscopic" cross-section, in which certain background lines that would otherwise be visible in a "true" cross-section are omitted for clarity of illustration. Additionally, some reference numbers may be omitted in certain figures for clarity. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Position sensing systems and waveguides according to the present disclosure will now be described more fully with reference to the accompanying drawings, in which embodiments of the position sensing systems and waveguides are shown. However, the position sensing systems and waveguides may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the systems and methods to those skilled in the art.

[0019] The present disclosure describes several exemplary embodiments of a propagation velocity compensated position system sensor including a PCB-based pulsed waveguide (PWG). Generally, an example of a PWG position sensor incorporating a waveguide and a magnet. In some embodiments, the present disclosure provides compensation by measuring both the reflected pulse and the terminal pulse. It is noted that the exemplary sensors detailed herein may be implemented in a variety of different systems, such as, for example, a fluid level system, a gear box, a welding machine, a robotic system, etc. However, the examples should not be limited in this context. Additionally, the present disclosure may be implemented to compensate for variations in propagation velocity due to temperature, external magnetic fields, manufacturing tolerances, changes in the characteristic response of the waveguide due to aging of the waveguide, etc. However, this is not intended to be limiting.

[0020] FIG. 2 illustrates a block diagram of a position detection system 200 arranged in accordance with at least some embodiments of the present disclosure. The system 200 includes a position sensor 210 (sometimes referred to herein as a “sensor”) having a waveguide 212 and a magnet 214. In some embodiments, the waveguide 212 is a PWG. In other embodiments, the waveguide 212 may be, for example, a microstrip waveguide, a stripline waveguide, a rectangular waveguide, or the like. Furthermore, the magnet 214 may be any of a variety of types of magnets (e.g., permanent magnets, electromagnets, or the like). The magnet 214 is movable relative to the waveguide 212. In general, the magnet 214 creates a point of impedance discontinuity 211 in the waveguide 212. The impedance discontinuity 211 is created at the location of the magnet 214 relative to the waveguide 212. The position of the waveguide 212 relative to the magnet 214 can be determined based on the initial pulse (e.g., 221), the reflected pulse (e.g., 223), and the terminal pulse (e.g., 225). Notably, this position may be determined regardless of the propagation speed of the wave within the waveguide 212.

[0021] In practice, either the magnet 214 or the waveguide 212 may be attached to the movable object whose position is to be determined. For example, in some embodiments, the magnet 214 can be affixed to the movable object (e.g., a sewing head, a laser, a welding tip, a liquid float, etc.). The waveguide 212 can be affixed to a cooperating structure that may be positioned along the path of the movable object. As another example, in some embodiments, the waveguide 212 can be affixed to the movable object while the magnet 214 is affixed to the cooperating structure. Thus, during operation, as the movable object moves, its position relative to the cooperating structure can be determined based on determining the position of the waveguide 212 relative to the magnet 214.

[0022] To determine the position of the waveguide 212 relative to the magnet 214, the system 200 may include a compensator 202 having a pulse generator 220 and a position determination module 230. The pulse generator 220 and the position determination module 230 are operatively connected to the waveguide 212 (e.g., via an electrical connection, etc.). The pulse generator 220 may be configured to generate a signal pulse (e.g., pulse 221), where the pulse 221 is transmitted to the waveguide 212 and reflected at the impedance discontinuity 211, resulting in a reflected pulse 223. Further, the pulse 221 is transmitted through the waveguide and exits the waveguide 212 as a terminal pulse 225. The compensator 202 is configured to determine the position of the waveguide 212 relative to the magnet 214 based on the pulse 221, the reflected pulse 223, and the terminal pulse 225. In some examples, compensator 202 may be configured to determine a position of waveguide 212 relative to magnet 214 based at least in part on controlling the timing of pulse 221, e.g., by controlling a period for the series of pulses 221. In some examples, compensator 202 may be configured to determine a position of waveguide 212 relative to magnet 214 based at least in part on comparing the time between pulse 221 and terminal pulse 225 to reflected pulse 223.

[0023] In some examples, system 200 may be configured to determine, in part, the position of waveguide 212 relative to magnet 214 by controlling the timing of pulses 221. For example, the period between pulses 221 may be controlled to compensate for temperature dependence of the time between when pulse 221 is transmitted into waveguide 212 and when reflected pulse 223 exits waveguide 212.

[0024] 3 illustrates a block diagram of an exemplary implementation of the compensator 302. Without limitation, the compensator 302 may be implemented as the compensator 202 in the system 200 of FIG. 2. The compensator 302 may include a pulse generator 320 and a position determination module 330. As shown, the pulse generator 320 is operatively connected to the waveguide 212 to both transmit a pulse 221 to the waveguide and receive a terminal pulse 225 from the waveguide 212. Additionally, the position determination module 330 is operatively connected to both the pulse generator 320 and the waveguide 212 to receive the pulse 221 and the reflected pulse 223.

[0025] The pulse generator 320 may be configured to generate a series of pulses 221, with the period (e.g., the time between pulses 221) corresponding to the time between pulse 221 and the terminal pulse 225. As will be appreciated, this period may change during operation and can be dynamically updated by the pulse generator 320. Thus, as the temperature changes and / or the speed of the waves propagating through the waveguide 212 changes (e.g., due to temperature, etc.), the time, and corresponding period, will change.

[0026] 4A-4C show a waveguide 412 according to an embodiment of the present disclosure. The waveguide 412 may be part of the position sensor 210 shown in FIG. 2 described herein, and the waveguide 412 may be configured as a PCB layer stack-up. FIG. 4A shows an exterior (e.g., PCB layer) of the waveguide 412 including a substrate layer 414. FIGS. 4B-4C show the waveguide 412 with the substrate layer 414 removed to better view the conductive winding 415 (e.g., copper) surrounding the magnetic layer 418. Without limitation, the magnetic layer 418 may be a ferrite strip extending between the first and second ends 420, 422 (FIG. 4A) of the waveguide 412. In some embodiments, there may be more than one magnetic layer 418. A plurality of traces 426 are aligned along the outer edge of the conductive winding 415.

[0027] Without limitation, the substrate layer 414 may be made from an epoxy or polyimide resin. In some cases, the resin may be reinforced with a woven matrix such as glass cloth or chopped fiber. The substrate layer 414 may alternatively be made of a ceramic or a rigid polymer. Also, this list of acceptable substrate materials is not exhaustive and other materials may be used. The materials and manufacturing techniques used to form substrates such as PCBs are well known to those skilled in the art.

[0028] Turning now to Figures 5-6, the waveguide 412 will be described in more detail. As shown, the waveguide 412 may be arranged as a stack of layers (e.g., L1-L6) connected / coupled to one another. In some embodiments, the waveguide 412 may be surrounded by a first substrate layer 414A and a second substrate layer 414B, where the first substrate layer 414A is provided on a first plating layer (L1) 431. In some embodiments, the first plating layer 431 may be a reference plane made of copper. As mentioned above, the first and second substrate layers 414A, 414B may be made of PCB type materials.

[0029] As further shown, the waveguide 412 may include a first core layer 441 and a second core layer 442 surrounding the magnetic layer 418. In some embodiments, the first and second core layers 441, 442 may be made of FR-4 copper clad laminate. While only two core layers are shown, it will be understood that three or more core layers are possible in other embodiments. Conductive windings 415 (L2 & L5) may be provided around the first core layer 441, the second core layer 442, and the magnetic layer 418. In some embodiments, the waveguide 412 may include an insulating layer 432, and the magnetic layer 418 is embedded within or otherwise surrounded by the insulating layer 432. Without limitation, the insulating layer 432 may be an epoxy, such as a reinforced cloth pre-impregnated with epoxy resin. As further shown, the waveguide 412 may include a second magnetic layer 419 between the first core layer 441 and the first substrate layer 414A, the second magnetic layer 419 being embedded in or otherwise surrounded by a second insulating layer 433 (e.g., epoxy). The second insulating layer 433 may be disposed below the first plating layer 431.

[0030] As further shown, a second plating layer 444 (L6) may be provided on the second substrate layer 414B, a third plating layer 445 (L3) may be provided on the insulating layer 432, and a fourth plating layer 446 (L4) may be provided on the second core layer 442. Without limitation, the second plating layer 444 may be a reference plane including a layer of copper 449. In some embodiments, the fourth plating layer 446 includes a ground connection 453 for the waveguide 412. A third insulating layer (e.g., epoxy) 447 may be provided between the winding 415 and the second plating layer 444.

[0031] The PCB-based stack design of the waveguide 412 allows for a variety of configurations. For example, as shown in the top view of FIG. 7A, the waveguide 412 may be configured with one or more bell-shaped portions. More specifically, the waveguide 412 may include a first bell-shaped portion 461 at the first end 420 and a second bell-shaped portion 462 at the second end 422. A relatively narrow central portion 463 is provided between the first and second bell-shaped portions 461, 462. The first and second bell-shaped portions 461, 462 represent regions of delay in the beginning and ending of the detection process as the magnet 417 moves relative to the waveguide 412, for example, from the first end 420 toward the second end 422. Without limitation, the first and second bell-shaped portions 461, 462 may be of the same or different dimensions.

[0032] In other embodiments, the waveguide 412 may be configured as a semicircle or U-shape, as shown in the side perspective view of FIG. 7B. More specifically, the waveguide 412 may include a first end 420 facing a second end 422, spaced apart from one another by a gap 466. A central portion 463 between the first and second ends 420, 422 may be curved or looped. Each of the first and second ends 420, 422 may represent a "dead zone" during the detection process as the magnet 417 moves relative to the waveguide 412, for example, from the first end 420 toward the second end 422. In the embodiment of FIG. 7C, the waveguide 412 may be configured as a wave including one or more protrusions and recesses between the first end 420 and the second end 422. It will be understood that a wide variety of shapes and configurations are possible within the scope of the present disclosure.

[0033] The above description is provided for illustrative purposes, and the description is not intended to limit the disclosure to one or more forms disclosed herein. For example, various features of the disclosure may be grouped together into one or more aspects, embodiments, or configurations for the purpose of organizing the disclosure. However, it should be understood that various features of a particular aspect, embodiment, or configuration of the disclosure may be combined with alternative aspects, embodiments, or configurations. Moreover, the following claims are hereby incorporated into this detailed description, with each claim standing on its own as a separate embodiment of the disclosure.

[0034] As used herein, elements or steps described in the singular and preceded by the word "a" or "an" are to be understood as not excluding a plurality of elements or steps, unless such exclusion is expressly stated. Moreover, references to "one embodiment" of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments incorporating the same described features.

[0035] The use of "including," "comprising," or "having" and variations thereof herein is intended to encompass the items listed thereafter and equivalents thereof as well as additional items. Thus, the terms "including," "comprising," or "having" and variations thereof are open-ended and can be used interchangeably herein.

[0036] The phrases "at least one," "one or more," and "and / or," as used herein, are open-ended expressions that function both conjunctively and non-conjunctively. For example, the expressions "at least one of A, B, and C," "at least one of A, B, or C," "one or more of A, B, and C," "one or more of A, B, or C," and "A, B, and / or C" mean A only, B only, C only, A and B together, A and C together, B and C together, or A, B, and C together.

[0037] All directional designations (e.g., proximal, distal, upper, lower, upward, downward, left, right, lateral, longitudinal, forward, rear, top, bottom, above, below, vertical, horizontal, radial, axial, clockwise, and counterclockwise) are used for identification purposes only to aid in the reader's understanding of this disclosure and do not create limitations on the location, orientation, or use of the disclosure, among others. Connection designations (e.g., attached, coupled, connected, and joined) should be interpreted broadly and may include intermediate members between groups of elements and relative movement between the elements, unless otherwise indicated. Thus, connection designations do not necessarily imply that two elements are directly connected in a fixed relationship to each other.

[0038] Further, identifying designators (e.g., primary, secondary, first, second, tertiary, fourth, etc.) are not intended to imply importance or priority, but are used to distinguish one feature from another. The drawings are for illustrative purposes only, and the dimensions, positions, order, and relative sizes reflected in the drawings attached hereto may vary.

[0039] Furthermore, the terms "substantially" or "substantially" and "approximately" or "nearly" can be used interchangeably in some embodiments and can be described using any relative measurement acceptable to those skilled in the art. For example, these terms can serve as a comparison to a reference parameter to indicate a deviation that can provide the intended function. Without being limiting, the deviation from the reference parameter can be, for example, less than 1%, less than 3%, less than 5%, less than 10%, less than 15%, less than 20%, etc. The present disclosure is not limited in scope by the specific embodiments described herein. Naturally, other various embodiments of the present disclosure and modifications thereto, in addition to those described herein, will become apparent to those skilled in the art from the above description and the accompanying drawings. Thus, such other embodiments and modifications are intended to be within the scope of the present disclosure. Furthermore, the present disclosure has been described herein in the context of specific implementations in specific environments for specific purposes. Those skilled in the art will recognize that the usefulness is not limited thereto, and the present disclosure may be beneficially implemented in any number of environments for any number of purposes. Thus, the claims set forth below should be construed in light of the full breadth and spirit of the present disclosure as described herein.

Claims

1. a waveguide for receiving and transmitting pulses; a magnet movable relative to the waveguide; A position detection system comprising: The waveguide is a first core layer and a second core layer; a magnetic layer between the first core layer and the second core layer; a conductive winding around the first core layer, the second core layer and the magnetic layer; a first substrate layer above the conductive winding and a second substrate layer below the conductive winding; having the waveguide further comprises an epoxy layer, the magnetic layer being embedded within the epoxy layer; The waveguide is a second magnetic layer between the first core layer and the first substrate layer, the second magnetic layer being embedded in a second epoxy layer; a first plating layer overlying the second epoxy layer; a second plating layer on the second substrate layer; a ground layer between the second core layer and the magnetic layer; Further comprising Location detection system.

2. 2. The position detection system of claim 1, wherein the waveguide further comprises a third epoxy layer between the conductive winding and the second plating layer.

3. The position detection system according to claim 1 or 2, wherein the first substrate layer and the second substrate layer are each a printed circuit board.

4. 4. The position detection system according to claim 1, wherein the first core layer and the second core layer are made of FR-4 copper clad laminate.

5. 5. The position detection system of claim 1, wherein the waveguides are arranged as a semicircle or a wave.

6. The position detection system of claim 1 , wherein the waveguide has one or more bell-shaped sections.

7. a waveguide for receiving and transmitting pulses, said waveguide being constructed as a stack of layers; a magnet movable relative to the waveguide; A position detection system comprising: The layer stack of the waveguide comprises: a first core layer and a second core layer; a magnetic layer between the first core layer and the second core layer; a conductive winding around the first core layer, the second core layer and the magnetic layer; a first substrate layer above the conductive winding and a second substrate layer below the conductive winding; having the stack of layers further comprises an epoxy layer, the magnetic layer being embedded within the epoxy layer; The stack of layers comprises: a second magnetic layer between the first core layer and the first substrate layer, the second magnetic layer being embedded in a second epoxy layer, the epoxy layer and the second epoxy layer being made of a reinforcement cloth pre-impregnated with epoxy resin; a first plating layer overlying the second epoxy layer; a second plating layer on the second substrate layer; a ground layer between the second core layer and the magnetic layer; Further comprising Location detection system.

8. 8. The position sensing system of claim 7, wherein the stack of layers further comprises a third epoxy layer between the conductive winding and the second plating layer.

9. 9. The position detection system according to claim 7 or 8, wherein the first substrate layer and the second substrate layer are each a printed circuit board.

10. 10. The position detection system according to claim 7, wherein the first core layer and the second core layer are made of FR-4 copper clad laminate.

11. A waveguide for receiving and transmitting pulses, the waveguide comprising: a first core layer and a second core layer; a magnetic layer between the first core layer and the second core layer, the magnetic layer being embedded in a first insulating material; a conductive winding around the first core layer, the second core layer and the magnetic layer; a first substrate layer above the conductive winding and a second substrate layer below the conductive winding; a second magnetic layer between the first core layer and the first substrate layer, the second magnetic layer being embedded in a second insulating material, the first insulating material and the second insulating material being a reinforcing cloth pre-impregnated with an epoxy resin; a first plating layer overlying the second insulating material; a second plating layer on the second substrate layer; a ground layer between the second core layer and the magnetic layer; A waveguide comprising:

12. 12. The waveguide of claim 11, further comprising a third epoxy layer between the conductive winding and the second plating layer.

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