Magnetic Long Range Position Sensor

Abstract

To provide magnetic position sensors for measuring relatively long traveling ranges of a target.SOLUTION: A magnetic position sensor provided herein comprises a first magnetic rod including a first end and a second end, and a second magnetic rod including a third end and a fourth end, the first end and the third end being at a first distance and the second end and the fourth end being at a second distance greater than the first distance. The magnetic position sensor further includes a magnet configured to travel relative to the first magnetic rod and the second magnetic rod along a first axis, and one or more magnetic sensors communicatively coupled to the magnet.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] Related Applications

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 005,914, filed April 6, 2020, the entire contents of which are incorporated herein by reference.

[0002]

[0002] Embodiments relate to magnetic position sensors. [Background technology]

[0003] As the name suggests, magnetic position sensors are used to measure the position of objects or device components. For example, it is often useful to know the position of vehicle seats, components in braking systems, components in clutches, floats in fluid level systems, and other objects or components. The position information can be used, among other things, to adjust the operation of the system or to provide an indication of the system's status (e.g., fluid level "empty" or "full" based on information provided by the float and processed in a computer or similar device). Summary of the Invention [Problem to be solved by the invention]

[0004] It is often useful to measure the movement of an object in a linear or rotary / angular position system. Among other things, the embodiments provided herein help solve problems associated with the cost and technical complexity of linear and angular magnetic position sensors for measuring relatively long ranges of movement of an object. Additionally, the embodiments provide, among other things, flexibility in sensor package design, from small to large footprints. The embodiments also provide, among other things, improved accuracy, improved linearity, and reduced mechanical and magnetic errors (hysteresis). [Means for solving the problem]

[0005] One embodiment provides a magnetic position sensor including a first magnetic rod including a first end and a second end and a second magnetic rod including a third end and a fourth end. The first end and the third end are at a first distance from each other. The second end and the fourth end are at a second distance from each other, the second distance being greater than the first distance. The magnetic position sensor also includes a magnet configured to move relative to the first and second magnetic rods along a central axis. One or more magnetic sensors are communicatively coupled to the magnet.

[0006] In some embodiments, the magnetic position sensor includes a gap between the first magnetic rod and the second magnetic rod. The gap has a first width (equal to the first distance) between the first end and the third end. The gap widens to a second width (equal to the second distance) between the second end and the fourth end. In some examples, the gap increases linearly from the first distance to the second distance. In some embodiments, a central axis intersects the center of the gap between the first end and the third end. The central axis also intersects the center of the gap between the second end and the fourth end.

[0007] In some embodiments, the first magnetic rod and the second magnetic rod are fixed, and the magnet moves along the central axis. In some embodiments, the magnet is fixed, and the first magnetic rod and the second magnetic rod move along the central axis between the magnet and one or more magnetic sensors. In some embodiments, the one or more magnetic sensors include a first magnetic sensor fixed between the first end and the third end, and a second magnetic sensor disposed on the opposite side of the magnet.

[0008] In some embodiments, the first magnetic rod and the second magnetic rod are straight. In some embodiments, the first magnetic rod and the second magnetic rod are curved. In some embodiments, the first magnetic rod and the second magnetic rod are separated by a fixed angle of θ degrees (e.g., about 1 degree). In some embodiments, one or more magnetic sensors sense magnetic flux to determine the position of the magnet.

[0009] Another embodiment provides a position detection system including a track, a magnet, and a magnetic position sensor including one or more magnetic sensors. The magnetic sensors are configured to determine a position of the magnet along the track based on magnetic flux. The system also includes one or more temperature sensors connected to the magnetic position sensor and the first and second magnetic rods, and an electronic processor connected to the magnetic position sensor and the temperature sensors. The electronic processor is configured to receive one or more position signals from the magnetic position sensors and one or more temperature signals from the temperature sensors, and to determine a position of the magnet based on the one or more position signals and the one or more temperature signals.

[0010] In some embodiments, the track is comprised of a first conductive rod and a second conductive rod. In some embodiments, the first conductive rod extends substantially along a first axis, and the second conductive rod extends substantially along a second axis different from the first axis. In some embodiments, the second axis is offset from the first axis by a fixed angle of θ degrees (e.g., about 1 degree). In some embodiments, the first conductive rod and the second conductive rod each extend approximately L FR or L SR (e.g., about 550 mm long). In some embodiments, the first conductive rod and the second conductive rod can have a relative permeability ranging from a low value to a high value.

[0011] In some embodiments, the one or more magnetic sensors include a first magnetic sensor disposed under the track and a second magnetic sensor connected to the track. In some embodiments, the position signal from the magnetic position sensor is based on magnetic flux. In some embodiments, the track is substantially linear. In some embodiments, the track is substantially arc-shaped. In some embodiments, the track is comprised of at least one selected from the group consisting of carbon steel 1010, pure iron, and mu-metal, which is a metallic group of materials having low to high relative magnetic permeability.

[0012]

[0012] Other aspects and embodiments will become apparent by consideration of the detailed description and accompanying drawings.

[0013] The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee. [Brief explanation of the drawings]

[0013] [Figure 1]

[0014] 1A, 1B, 1C, and 1D are perspective views of a linear magnetic position sensor according to an embodiment. [Figure 2]

[0015] FIG. 2 is a top view of the linear magnetic position sensor of FIGS. 1A-1D illustrating the magnetic flux experienced by the track, according to some embodiments. [Figure 3A]

[0016] FIG. 3A is a top view of an angular magnetic position sensor illustrating magnets in various positions, according to some embodiments. [Figure 3B] FIG. 3B is a top view of an angular magnetic position sensor showing the magnet in various positions, according to some embodiments. [Figure 3C]FIG. 3C is a top view of an angular magnetic position sensor showing the magnet in various positions, according to some embodiments. [Figure 3D] FIG. 3D is a top view of an angular magnetic position sensor showing the magnet in various positions, according to some embodiments. [Figure 4]

[0017] FIG. 4 is a perspective view of the angular magnetic position sensor of FIGS. 3A-3D illustrating the magnetic flux experienced by the track, according to some embodiments. [Figure 5A]

[0018] FIG. 5A is a graph comparing the magnetic flux experienced by the magnetic sensors of FIGS. 1 and 3, according to some embodiments. [Figure 5B] FIG. 5B is a graph comparing the magnetic flux experienced by the magnetic sensors of FIGS. 1 and 3, according to some embodiments. [Figure 5C-1] FIG. 5C is a graph comparing the magnetic flux experienced by the magnetic sensors of FIGS. 1 and 3, according to some embodiments. [Figure 5C-2] FIG. 5C is a graph comparing the magnetic flux experienced by the magnetic sensors of FIGS. 1 and 3, according to some embodiments. [Figure 6]

[0019] FIG. 6 is a diagram illustrating a system incorporating a magnetic position sensor, according to some embodiments. [Figure 7]

[0020] FIG. 7 is a block diagram of a controller according to some embodiments. [Figure 8]

[0021] FIG. 8 illustrates a method performed by the controller of FIG. 7 according to some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0014]

[0022] Before any embodiments are described in detail, it is to be understood that the embodiments are not limited in their application to the details of construction and the arrangements of components set forth in the following description or illustrated in the following drawings. Other embodiments are possible, and the described and / or illustrated embodiments are capable of being practiced or carried out in various ways.

[0015]

[0023] 1A-1D illustrate one embodiment of a magnetic position sensor 10 including a magnet 12 disposed on a first magnetic rod 14a and a second magnetic rod 14b separated by a gap 16. The first magnetic rod 14a and the second magnetic rod 14b may form a single track 14. In this example, the first magnetic rod 14a and the second magnetic rod 14b are substantially straight. In some embodiments, the first magnetic rod 14a and the second magnetic rod 14b each have a length of 550 mm, a width of 11 mm, and a height of 2 mm. In some embodiments, the first magnetic rod 14a and the second magnetic rod 14b are composed of at least one material selected from the group consisting of conductive materials, magnetoresistive materials, ferromagnetic materials, and ferrous materials.

[0016]

[0024] As can be seen in FIG. 1B, the first magnetic rod 14a has a length L FR The first axis 22a is located at the center C of the first end 18a and the second end 20a. F The second magnetic rod 14b crosses the length L of the second magnetic rod 14b. SR The second axis 22b is located at the center C of the third end 18b and the fourth end 20b. S1B . Gap 16 is defined by a first distance or width W1 between first end 18a and third end 18b and a second distance or width W2 between second end 20a and fourth end 20b. In some embodiments, first distance W1 may be approximately 1.5 mm. In some embodiments, second distance W2 may be approximately 20.6 mm. Gap 16 may cause first magnetic rod 14a and second magnetic rod 14b to form a substantially "V" shape, as the width of gap 16 increases linearly from first distance W1 to second distance W2. In some embodiments, first magnetic rod 14a and second magnetic rod 14b are separated by an angle represented by θ in FIG. 1B . In some embodiments, angle θ is approximately 1 degree.

[0017]

[0025] In some embodiments, the magnet 12 is positioned above the first magnetic rod 14a and the second magnetic rod 14b such that the magnet 12 can move along the track 14. In some embodiments, the magnet 12 has a length of 21.5 mm, a width of 11.0 mm, and a height of 2.0 mm. The magnet 12 is spaced apart by a vertical gap G V The vertical gap G V may be, for example, about 0.5 mm to 1.0 mm. When moving, magnet 12 may move along the center of track 14, indicated by central axis 24. Central axis 24 intersects the center of the first distance created by first end 18a and third end 18b and intersects the center of the second distance created by second end 20a and fourth end 20b. As magnet 12 moves along track 14, the magnetic flux generated by magnet 12 may be affected by first magnetic rod 14a and second magnetic rod 14b. In some embodiments, magnet 12 moves relative to track 14, and track 14 remains stationary. In other embodiments, magnet 12 is stationary, and track 14 moves relative to magnet 12.

[0018]

[0026] In some embodiments, the magnetic position sensor 10 includes a first magnetic sensor 30 and a second magnetic sensor 32 communicatively coupled to the magnet 12. The first magnetic sensor 30 and the second magnetic sensor 32 may be, for example, Hall sensors configured to detect magnetic flux. The first magnetic sensor 30 may be disposed, for example, between the first end 18 a and the third end 18 b. In some embodiments, the first magnetic sensor 30 is connected to the body or device floor (not shown) of the magnetic position sensor 10 or the device in which the magnetic position sensor 10 is disposed. In some embodiments, the second magnetic sensor 32 may be disposed on the central axis 24, for example, below the track 14. In some embodiments, the second magnetic sensor 32 may be coupled to the magnet 12 such that the second magnetic sensor 32 can move substantially uniformly below and with the magnet 12.

[0019]

[0027] In some embodiments, the first magnetic sensor 30 and the track 14 are stationary as the magnet 12 moves along the track 14. For example, the first magnetic sensor 30 may be coupled to the track 14. In some embodiments, the second magnetic sensor 32 and the magnet 12 are stationary as the track 14, along with the coupled first magnetic sensor 30, moves between the second magnetic sensor 32 and the magnet 12. In some embodiments, only the first magnetic sensor 30 is utilized by or present within the magnetic position sensor 10. In other embodiments, only the second magnetic sensor 32 is utilized by or present within the magnetic position sensor 10. In some embodiments, both the first magnetic sensor 30 and the second magnetic sensor 32 are utilized by or present within the magnetic position sensor 10. For example, the first magnetic sensor 30 may be stationary as the second magnetic sensor 32 and the magnet 12 move along the track 14.

[0020]

[0028] 2 illustrates the magnetic flux experienced by track 14 as magnet 12 moves relative to track 14. For example, in image 200, magnet 12 is positioned at position P1 approximately at first end 18a and third end 18b. The magnetic field is strongest at first end 18a and third end 18b. Thus, at position P1, first magnetic sensor 30 and second magnetic sensor 32 experience the greatest magnetic flux (e.g., a high level of magnetic flux or a maximum level of magnetic flux) compared to positions P2, P3, and P4.

[0021]

[0029] In image 202, magnet 12 is positioned at position P2, approximately one-third of the way along or across trajectory 14. At position P2, the magnetic field decreases at first end 18a and third end 18b. Thus, first magnetic sensor 30 experiences less magnetic flux (e.g., a medium level of magnetic flux). In some embodiments, second magnetic sensor 32 moves with magnet 12. While second magnetic sensor 32 continues to experience a large magnetic flux, the increased size of gap 16 affects the direction of the magnetic field. Thus, second magnetic sensor 32 experiences a larger change in magnetic flux compared to position P1.

[0022]

[0030] In image 204, magnet 12 is positioned at position P3, approximately two-thirds of the way along or across trajectory 14. At position P3, the magnetic field further decreases at first end 18a and third end 18b. Thus, first magnetic sensor 30 experiences even less magnetic flux (e.g., a lower level of magnetic flux). In some embodiments, second magnetic sensor 32, which continues to move with magnet 12, experiences a larger change in magnetic flux (compared to position P2) due to the increased size of gap 16.

[0023]

[0031] In image 206, magnet 12 is positioned at position P4, completely passing along trajectory 14 at second end 20a and fourth end 20b. At position P4, first magnetic sensor 30 experiences the lowest level of magnetic flux compared to positions P1, P2, P3, and P4. In some embodiments, second magnetic sensor 32, also positioned at second end 20a and fourth end 20b, experiences the largest change in magnetic flux (compared to positions P1, P2, and P3) due to the increased size of gap 16.

[0024]

[0032] 3A-3D illustrate another embodiment of the magnetic position sensor 10, which includes a first curved magnetic rod 62a and a second curved magnetic rod 62b that form a curved track 62. The curved track 62 can be an arc, an ellipse, a crescent, a circle, or another curved shape. In some embodiments, as illustrated in FIG. 3A, the first curved magnetic rod 62a includes a first end 70a and a second end 72a, similar to the first magnetic rod 14a. The first end 70a and the second end 72a are spaced apart by a distance L defined by the length of the first curved magnetic rod 62a. FA In some embodiments, the second curved magnetic rod 62b includes a third end 70b and a fourth end 72b, similar to the second magnetic rod 14b. The third end 70b and the fourth end 72b are separated by a distance L defined by the length of the second curved magnetic rod 62b. SA It's just a distance away.

[0025]

[0033] A curved gap 68 is disposed between the first curved magnetic rod 62a and the second curved magnetic rod 62b. Similar to gap 16, curved gap 68 increases from a third distance or width W3 between a first end 70a of the first curved magnetic rod 62a and a third end 70b of the second curved magnetic rod 62b to a fourth distance or width W4 between a second end 72a of the first curved magnetic rod 62a and a fourth end 72b of the second curved magnetic rod 62b. In some embodiments, the first curved magnetic rod 62a and the second curved magnetic rod 62b are separated by an angle shown as ω in FIG. 3A .

[0026]

[0034] 3B-3D, magnetic position sensor 10 includes a magnet 60 that is substantially similar to magnet 12. A third magnetic sensor 64 and a fourth magnetic sensor 66 function similarly to first magnetic sensor 30 and second magnetic sensor 32, respectively. Magnet 60 may be configured to move along a central axis 74 that is similar to central axis 24.

[0027]

[0035] In some embodiments, the third magnetic sensor 64 and the curved track 62 are substantially stationary as the magnet 60 moves along the curved track 62. For example, the third magnetic sensor 64 may be coupled to the curved track 62. In some embodiments, the magnet 60 and the coupled fourth magnetic sensor 66 are substantially stationary as the curved track 62 moves between the magnet 60 and the fourth magnetic sensor 66. In some embodiments, only the third magnetic sensor 64 is utilized by or present within the magnetic position sensor 10. In other embodiments, only the fourth magnetic sensor 66 is utilized by or present within the magnetic position sensor 10. In some embodiments, both the third magnetic position sensor 64 and the fourth magnetic position sensor 66 are utilized by or present within the magnetic position sensor 10. For example, the third magnetic position sensor 64 can be stationary as the fourth magnetic position sensor 66 and the magnet 60 move along the track 62.

[0028]

[0036] 4 illustrates the magnetic flux experienced by the curved track 62 as the magnet 60 moves relative to the curved track 62. For example, in image 400, the magnet 60 is positioned approximately at position P11, i.e., at the first and third ends 70a and 70b of the first and second curved magnetic rods 62a and 62b (e.g., the beginning of the curved track 62). At position P11, the magnetic field is strongest at the beginning of the curved track 62. Thus, at this position, the third and fourth magnetic sensors 64 and 66 experience the greatest magnetic flux compared to positions P12 and P13.

[0029]

[0037] In image 402, magnet 60 is positioned at position P12, i.e., approximately halfway along the path of curved trajectory 62. At position P12, the magnetic field decreases at the beginning of curved trajectory 62. Thus, third magnetic sensor 64 experiences less magnetic flux (e.g., a medium level of magnetic flux). In some embodiments, fourth magnetic sensor 66 moves with magnet 60. Fourth magnetic sensor 66 continues to experience a large magnetic flux, but the increased size of curved gap 68 affects the direction of the magnetic field. Thus, fourth magnetic sensor 66 experiences a larger change in magnetic flux compared to position P11.

[0030]

[0038] In image 404, magnet 60 is at position P13, positioned substantially across or along curved trajectory 62, approximately at second end 72a of first curved magnetic rod 62a and fourth end 72b of second curved magnetic rod 62b (e.g., at the end of curved trajectory 62). Thus, third magnetic sensor 64 experiences even less magnetic flux (e.g., a lower level of magnetic flux) compared to position P12. In some embodiments, fourth magnetic sensor 66, positioned at the end of curved trajectory 62, also experiences the greatest change in magnetic flux associated with positions P11, P12, and P13 due to the increased size of curved gap 68.

[0031]

[0039] In some embodiments, the material of the tracks 14 and 62 affects the magnetic field of the magnets 12 and 60 and, therefore, the magnetic flux experienced by the magnetic sensors 30, 32, 64, and 66. For example, mu-metal has a higher magnetic permeability than AISI steel 1010, more commonly referred to as carbon steel. Different permeabilities allow for different reorientations of the magnetic flux density of the magnets 12 and 60. For example, a higher magnetic permeability attracts more magnetic flux density, resulting in more magnetic flux concentrating in the path formed by the tracks 14 and 62. For comparison, a lower magnetic permeability attracts less magnetic field, instead acting similarly on the magnet itself. Figures 5A-5B illustrate graphs showing the magnetic flux experienced by the first magnetic sensor 30. In Figure 5A, the track 14 is made of mu-metal. In Figure 5B, the track 14 is made of AISI steel 1010. 5C illustrates a graph showing the magnetic flux experienced by the third magnetic sensor 64 when the track 62 is composed of at least one selected from the group consisting of AISI steel 1010, pure iron, and mu metal. Thus, the material of the tracks 14, 62 may be considered when implementing the magnetic position sensor 10.

[0032]

[0040] It should be understood that the angle θ can be chosen or selected for a particular application of the sensor. In some embodiments, the angle θ between the first magnetic rod 14a and the second magnetic rod 14b affects the magnetic field of the magnet 12. Thus, the angle θ affects the magnetic flux experienced by the magnetic sensors 30, 32. Similarly, in some embodiments, the angle ω between the first curved magnetic rod 62a and the second curved magnetic rod 62b affects the magnetic field of the magnet 60. Thus, the angle ω affects the magnetic flux experienced by the magnetic sensors 64, 66. If the selected angle θ or ω is too small (e.g., 0.5 degrees), each magnetic rod in the track 14, 62 will undergo magnetic field exchange, reducing the amount of magnetic flux density experienced by each magnetic sensor 30, 32, 64, 66. Thus, the angle θ or ω can be selected so that the magnets 12, 60 generate a desired magnetic flux density.

[0033]

[0041] FIG. 6 illustrates a block diagram of a system 600 incorporating the magnetic position sensor 10, according to some embodiments. In the illustrated example, the system 600 includes a temperature sensor 602 and an electronic controller 604 configured to receive signals from the magnetic position sensor 10 and the temperature sensor 602. The magnetic position sensor 10 is configured to transmit one or more magnetic position signals to the electronic controller 604 indicative of the position (e.g., location) of the magnet 12, 60. The temperature sensor 602 is configured to transmit one or more temperature signals to the electronic controller 604 based on at least one temperature selected from the group consisting of an ambient temperature and a temperature of the track 14, 62. In some embodiments, the electronic controller 604 may output an output signal to an external device based on the one or more temperature signals and the one or more magnetic position signals received from the magnetic position sensor 10. In some embodiments, the electronic controller 604 may output system software and hardware diagnostic fault codes to the external device. The diagnostic fault codes may be transmitted separately from or together with the magnetic position signals from the magnetic position sensor 10 and the temperature signal from the temperature sensor 602. In some embodiments, the magnetic position sensor 10 transmits one or more magnetic position signals directly to an external device, with or without embedded diagnostic fault codes.

[0034]

[0042] 7 illustrates a block diagram of electronic controller 604 (e.g., a computer, microcontroller, microprocessor, electronic processor, or similar device or devices). In the illustrated embodiment, electronic controller 604 includes an electronic processor 700, a memory 708, input devices 710, and output devices 712. Electronic processor 700, memory 708, input devices 710, and output devices 712, as well as the various modules or circuits connected to electronic controller 604, are connected by one or more control and / or data buses. Memory 708 includes program and data storage areas. The program and data storage areas may include a combination of different types of memory 708, such as machine-readable non-transitory memory, read-only memory (“ROM”), random access memory (“RAM”) (e.g., dynamic RAM (“DRAM”), synchronous DRAM (“SDRAM”), etc.), electrically erasable programmable read-only memory (“EEPROM”), flash memory, a hard disk, an SD card, or other suitable magnetic, optical, physical, or electronic memory device. The electronic processor 700 is coupled to the memory 708 and executes software instructions, which may be stored in the RAM of the memory 708 (e.g., during execution), in the ROM of the memory 708 (e.g., more or less permanently), or on another non-transitory computer-readable medium. Software included for the processes and methods of the system 600 may be stored in the memory 708 of the electronic controller 604. The software may include firmware, one or more applications, program data, filters, rules, one or more program modules, and other executable instructions. The electronic controller 604 is configured to retrieve from memory 708 and execute instructions related to, among other things, the control processes and methods described herein. In other configurations, the electronic controller 604 includes additional, fewer, or different components.

[0035]

[0043] For example, the electrical and (electro)magnetic properties (e.g., permeability) of components of the magnetic position sensor 10, such as the tracks 14, 62, may be temperature dependent. Thus, the magnetic flux experienced by the magnetic sensors 30, 32, 64, 66 may also be temperature dependent. In some embodiments, the electronic controller 604 is configured to determine the position of the magnets 12, 60 based on one or more magnetic position signals and one or more temperature signals.

[0036]

[0044] 8 illustrates a block diagram of a method 800 performed by the electronic controller 604, for example, to determine the position of a magnet. In block 802, the electronic controller 604 receives one or more magnetic position signals from the magnetic position sensors 10. The one or more magnetic position signals may be, for example, magnetic flux experienced by the first magnetic sensor 30, the second magnetic sensor 32, or a combination of the first magnetic sensor 30 and the second magnetic sensor 32. In some embodiments, the one or more magnetic position signals may represent magnetic flux experienced by the third magnetic sensor 64, the fourth magnetic sensor 66, or a combination of the third magnetic sensor 64 and the fourth magnetic sensor 66.

[0037]

[0045] In block 804, the electronic controller 604 receives one or more temperature signals from the temperature sensor 602. The temperature signals may represent the ambient temperature, the temperature of a component of the magnetic position sensor 10 (e.g., track 14, 62), or a combination of the ambient temperature and the temperature of a component of the magnetic position sensor 10. In block 806, the electronic controller 604 determines the position of the magnet 12, 60 based on the one or more magnetic position signals and the one or more temperature signals. In some embodiments, the electronic controller 604 transmits the position of the magnet 12, 60 to an external device. Prior to transmission, the position of the magnet 12, 60 may be conditioned using a filter (e.g., a low-pass filter, a high-pass filter, etc.), converted to a digital format, etc. In some embodiments, linearization of the output signal may be performed by the magnetic sensor 10, the electronic controller 604, or some combination thereof, prior to transmission to the external device.

[0038]

[0046] Water level sensor example

[0047] Water level detection is one of many applications of magnetic position sensor 10. In one example, a water tank includes four potential water levels (e.g., level 1, level 2, level 3, and level 4). In some embodiments, level 1 is a low water level (1 / 4), level 2 is a medium water level (1 / 2), level 3 is a high water level (3 / 4), and level 4 is full (1). The water tank may include, for example, a reservoir configured to hold water and one or more openings configured to allow water to enter or exit the reservoir. Magnetic position sensor 10 may be attached to the side of the reservoir, for example, such that first end 18 a and third end 18 b are located at the bottom of the reservoir and second end 20 a and fourth end 20 b are located at the top of the reservoir. Additionally, the magnet 12 is connected to or otherwise incorporated into a buoyant float such that the physical location of the magnet 12 corresponds to the physical elevation of the top surface of the water contained within the reservoir.

[0039]

[0048] 2, when the reservoir is at water level 1, the magnetic flux experienced by the magnetic position sensor 10 may be, for example, the magnetic flux shown by image 200. When the reservoir is at water level 2, the magnetic flux experienced by the magnetic position sensor 10 may be, for example, the magnetic flux shown by image 202. When the reservoir is at water level 3, the magnetic flux experienced by the magnetic position sensor 10 may be, for example, the magnetic flux shown by image 204. When the reservoir is at water level 4, the magnetic flux experienced by the magnetic position sensor 10 may be, for example, the magnetic flux shown by image 206.

[0040]

[0049] The electronic controller 604 receives one or more magnetic position signals from the magnetic position sensor 10. In some embodiments, the electronic controller 604 also receives one or more temperature signals indicative of the temperature of the water from the temperature sensor 602. Based on the one or more magnetic position signals and the one or more temperature signals, the electronic controller 604 determines the level of water stored in the reservoir of the water tank.

[0041]

[0050] Accordingly, embodiments provide, among other things, a magnetic position sensor. Various features and advantages are set forth in the following claims. [Item 1] 1. A magnetic position sensor, comprising: a first magnetic rod including a first end and a second end; a second magnetic rod including a third end and a fourth end, the first end and the third end being at a first distance, and the second end and the fourth end being at a second distance greater than the first distance; a magnet configured to move relative to the first and second magnetic rods along a central axis; and one or more magnetic sensors communicatively coupled to the magnet. [Item 2] 2. The magnetic position sensor of claim 1, further comprising a gap between the first magnetic rod and the second magnetic rod, the gap being the first distance between the first end and the third end, the gap widening to the second distance between the second end and the fourth end, and the gap linearly increasing from the first distance to the second distance. [Item 3] 3. The magnetic position sensor of claim 2, wherein the central axis intersects a center of the gap between the first end and the third end, and the central axis intersects a center of the gap between the second end and the fourth end. [Item 4] Item 2. The magnetic position sensor of item 1, wherein the first magnetic rod and the second magnetic rod are fixed, and the magnet moves along the central axis. [Item 5] Item 1, a magnetic position sensor according to item 1, wherein the magnet is fixed and the first magnetic rod and the second magnetic rod move along the central axis between the magnet and the one or more magnetic sensors. [Item 6] Item 1, wherein the one or more magnetic sensors include a first magnetic sensor fixed between the first end and the third end, and a second magnetic sensor positioned on the opposite side of the magnet. [Item 7] Item 2. The magnetic position sensor of item 1, wherein the first magnetic rod and the second magnetic rod are linear. [Item 8] Item 1, wherein the first magnetic rod and the second magnetic rod are curved. [Item 9] Item 1 . The magnetic position sensor of item 1 , wherein the first magnetic rod and the second magnetic rod are separated by a fixed angle of θ degrees. [Item 10] Item 1 , a magnetic position sensor according to item 1, wherein the one or more magnetic sensors sense magnetic flux to determine the position of the magnet. [Item 11] 1. A location detection system, comprising: a magnetic position sensor including a track, a magnet, and one or more magnetic sensors configured to determine a position of the magnet along the track based on magnetic flux; and one or more temperature sensors connected to the magnetic position sensor and the track; an electronic processor connected to said magnetic position sensor and said one or more temperature sensors; Equipped with The electronic processor receiving one or more position signals from the magnetic position sensor; receiving one or more temperature signals from the one or more temperature sensors; determining a position of the magnet based on the one or more position signals and the one or more temperature signals; A location detection system configured to: [Item 12] Item 12. The position detection system of item 11, wherein the track is composed of a first conductive rod and a second conductive rod. [Item 13] Item 13. The position detection system of item 12, wherein the first conductive rod extends substantially along a first axis and the second conductive rod extends substantially along a second axis different from the first axis. [Item 14] Item 14. The position detection system of item 13, wherein the second axis is offset from the first axis by a fixed angle of θ degrees. [Item 15] Item 13. The position detection system of item 12, wherein the first conductive rod and the second conductive rod have a length of approximately 550 mm. [Item 16] Item 12. The position detection system of item 11, wherein the one or more magnetic sensors include a first magnetic sensor positioned under the track, and the one or more magnetic sensors include a second magnetic sensor connected to the track. [Item 17] Item 12. The position detection system of item 11, wherein the position signal from the magnetic position sensor is based on magnetic flux. [Item 18] Item 12. The position detection system of item 11, wherein the trajectory is substantially linear. [Item 19] Item 12. The position detection system of item 11, wherein the trajectory is substantially arcuate. [Item 20] Item 12. The position detection system of item 11, wherein the track is constructed from a material selected from the group consisting of carbon steel, pure iron, and mu metal. [Explanation of symbols]

[0042] 10 Magnetic Position Sensor 12 Magnet 14 orbit 14a First magnetic rod 14b Second magnetic rod 16 Gap 18a First end 18b Third end 20a Second end 20b Fourth end 22a First axis 22b Second axis 24 Center axis 30 First magnetic sensor 32 Second magnetic sensor 60 Magnet 62 orbit 62a Magnetic Rod 62b Magnetic Rod 64 Third Magnetic Sensor 66 Fourth Magnetic Sensor 68 Gap 70a first end 70b Third end 72a second end 72b Fourth end 74 Center axis 200 images 202 images 204 images 206 images 400 images 402 images 404 images 600 System 602 Temperature Sensor 604 Electronic Controller 700 Electronic Processor 708 memory 710 Input Devices 712 output device C F center C S center G V vertical gap L FA distance L FR length L SA distance L SR length P1 position P2 position P3 position P4 position P11 position P12 position P13 position W1 First distance W2 Second distance W3 Third distance W4 Fourth distance θ angle ω angle

Claims

1. 1. A magnetic position sensor, comprising: a first magnetic rod including a first end and a second end; a second magnetic rod including a third end and a fourth end, the first magnetic rod and the second magnetic rod forming an orbit with a central axis located between the first magnetic rod and the second magnetic rod, the first end and the third end being separated by a first distance, and the second end and the fourth end being separated by a second distance greater than the first distance; a magnet spaced from the track by a vertical gap, the magnet configured to move along the central axis; a plurality of magnetic sensors communicatively coupled to the magnet; The magnetic position sensor, wherein the plurality of magnetic sensors includes a first magnetic sensor fixed between the first end and the third end, and a second magnetic sensor positioned on an opposite side of the track from the magnet and configured to move with the magnet.

2. 2. The magnetic position sensor of claim 1, further comprising a gap between the first magnetic rod and the second magnetic rod, the gap being the first distance between the first end and the third end, the gap widening to the second distance between the second end and the fourth end, and the gap increasing linearly from the first distance to the second distance.

3. 3. The magnetic position sensor of claim 2, wherein the central axis intersects a center of the gap between the first end and the third end, and the central axis intersects a center of the gap between the second end and the fourth end.

4. The magnetic position sensor of claim 1 , wherein the first magnetic rod and the second magnetic rod are fixed and the magnet moves along the central axis.

5. The magnetic position sensor of claim 1 , wherein the magnet is fixed, and the first magnetic rod and the second magnetic rod move along the central axis between the magnet and the plurality of magnetic sensors.

6. The magnetic position sensor of claim 1 , wherein the first magnetic rod and the second magnetic rod are linear.

7. The magnetic position sensor of claim 1 , wherein the first magnetic rod and the second magnetic rod are curved.

8. The magnetic position sensor of claim 1 , wherein the first magnetic rod and the second magnetic rod are separated by a fixed angle of θ degrees.

9. The magnetic position sensor of claim 1 , wherein the plurality of magnetic sensors sense magnetic flux to determine the position of the magnet.

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