Patent ID: 12189001

DETAILED DESCRIPTION

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

FIGS.1A-1Dillustrate one embodiment of a magnetic position sensor10that includes a magnet12situated above a first magnetic rod14aand a second magnetic rod14bseparated by a gap16. The first magnetic rod14aand the second magnetic rod14bmay form a singular track14. In this example, the first magnetic rod14aand the second magnetic rod14bare substantially linear. In some embodiments, the first magnetic rod14aand the second magnetic rod14beach have a length of 550 mm, a width of 11 mm, and a height of 2 mm. In some embodiments, the first magnetic rod14aand the second magnetic rod14bare composed of at least one material selected from a group consisting of a conductive material, a magneto-resistive material, a ferromagnetic material, and ferrous material.

As seen inFIG.1B, the first magnetic rod14aincludes a first end18aand a second end20aseparated by a length LFRof the first magnetic rod14a. A first axis22aintercepts a center CF of the first end18aand the second end20a. The second magnetic rod14bincludes a third end18band a fourth end20bseparated by a length LSRof the second magnetic rod14b. A second axis22bintercepts a center Cs of the third end18band the fourth end20b. The gap16is defined by a first distance or width W1between the first end18aand the third end18b, and a second distance or width W2between the second end20aand the fourth end20b. In some embodiments, the first distance W1may be approximately 1.5 mm. In some embodiments, the second distance W2may be approximately 20.6 mm. Due to the gap16, the first magnetic rod14aand the second magnetic rod14bmay form a substantially “V” shape, as the width of the gap16increases linearly from the first distance W1to the second distance W2. In some embodiments, the first magnetic rod14aand the second magnetic rod14bare separated by an angle, represented by θ inFIG.1B. In some embodiments, the angle θ is approximately 1 degree.

In some embodiments, the magnet12is situated above the first magnetic rod14aand the second magnetic rod14bso that the magnet12moves along the track14. In some embodiments, the magnet12has a length of 21.5 mm, a width of 11.0 mm, and a height of 2.0 mm. The magnet12may be separated from the track14by a vertical gap Gv. The vertical gap Gvmay be, for example, approximately 0.5 mm to 1.0 mm. When moving, the magnet12may move along the center of the track14, shown by the center axis24. The center axis24intercepts the center of the first distance created by the first end18aand the third end18b, and intercepts the center of the second distance created by the second end20aand the fourth end20b. As the magnet12moves along the track14, the magnetic flux created by the magnet12may be impacted by the first magnetic rod14aand the second magnetic rod14b. In some embodiments, the magnet12moves relative to the track14, and the track14remains stationary. In other embodiments, the magnet12is stationary and the track14moves relatively to the magnet12.

In some embodiments, the magnetic position sensor10includes a first magnetic sensor30and a second magnetic sensor32is communicatively coupled to the magnet12. The first magnetic sensor30and the second magnetic sensor32may be, for example, Hall sensors configured to detect magnetic flux. The first magnetic sensor30may be, for example, situated between the first end18aand the third end18b. In some embodiments, the first magnetic sensor30is connected to a body or device floor (not shown) of the magnetic position sensor10or a device in which the magnetic position sensor10is situated. In some embodiments, the second magnetic sensor32may be, for example, situated below the track14and on the center axis24. In some embodiments, the second magnetic sensor32may be coupled to the magnet12such that the second magnetic sensor32travels below and substantially even with the magnet12.

In some embodiments, the first magnetic sensor30and the track14are stationary as the magnet12moves along the track14. For example, the first magnetic sensor30may be coupled to the track14. In some embodiments, the second magnetic sensor32and the magnet12are stationary as the track14, with the coupled first magnetic sensor30, moves between the second magnetic sensor32and the magnet12. In some embodiments, only the first magnetic sensor30is utilized by or present within the magnetic position sensor10. In other embodiments, only the second magnetic sensor32is utilized by or present within the magnetic position sensor10. In some embodiments, both the first magnetic sensor30and the second magnetic sensor32are utilized by or present within the magnetic position sensor10. For example, the first magnetic sensor30may be stationary as the second magnetic sensor32and the magnet12move along the track14.

FIG.2illustrates the magnetic flux experienced by the track14as the magnet12moves relative to the track14. For example, in image200, the magnet12is situated at approximately the first end18aand the third end18bat position P1. The magnetic field is strongest at the first end18aand the third end18b. Accordingly, in position P1, the first magnetic sensor30and the second magnetic sensor32experience the greatest magnetic flux (for example, a large level of magnetic flux or a maximum level of magnetic flux) relative to positions P2, P3, and P4.

In image202, the magnet12is situated approximately ⅓ of the way along or across the track14at position P2. In position P2, the magnetic field has decreased at the first end18aand the third end18b. Accordingly, the first magnetic sensor30experiences less magnetic flux (for example, a medium level of magnetic flux). In some embodiments, the second magnetic sensor32travels with the magnet12. Although the second magnetic sensor32continues to experience a high amount of magnetic flux, the increase in the size of the gap16impacts the direction of the magnetic field. Accordingly, the second magnetic sensor32experiences a greater change in magnetic flux relative to position P1.

In image204, the magnet12is situated approximately ⅔ of the way along or across the track14at position P3. In position P3, the magnetic field has further decreased at the first end18aand the third end18b. Accordingly, the first magnetic sensor30experiences even less magnetic flux (for example, a low level of magnetic flux). In some embodiments, the second magnetic sensor32, which continues to travel with the magnet12, experiences a greater change in magnetic flux (relative to position P2) due to the increased size of the gap16.

In the image206, the magnet12is situated fully along across the track14at the second end20aand the fourth end20bat position P4. In position P4, the first magnetic sensor30experiences a lowest level of magnetic flux, relative to positions P1, P2, P3, and P4. In some embodiments, the second magnetic sensor32, also now situated at the second end20aand the fourth end20b, experiences a greatest change in magnetic flux (relative to positions P1, P2and P3) due to the increased size of the gap16.

FIGS.3A-3Dillustrate another embodiment of a magnetic position sensor10, where the magnetic position sensor10includes a first curved magnetic rod62aand a second curved magnetic rod62bforming a curved track62. The curved track62may be an arc, an oval, a crescent, a circle, or another curved shape. In some embodiments, as illustrated inFIG.3A, the first curved magnetic rod62aincludes a first end70aand a second end72asimilar to that of the first magnetic rod14a. The first end70aand the second end72aare separated by a distance LFA, defined by the length of the first curved magnetic rod62a. In some embodiments, the second curved magnetic rod62bincludes a third end70band a fourth end72bsimilar to that of the second magnetic rod14b. The third end70band the fourth end72bare separated by a distance LSA, defined by the length of the second curved magnetic rod62b.

A curved gap68is situated between the first curved magnetic rod62aand the second curved magnetic rod62b. Similar to the gap16, the curved gap68increases from a third distance or width W3between the first end70aof the first curved magnetic rod62aand the third end70bof the second curved magnetic rod62bto a fourth distance or width W4between the second end72aof the first curved magnetic rod62aand the fourth end72bof the second curved magnetic rod62b. In some embodiments, the first curved magnetic rod62aand the second curved magnetic rod62bare separated by an angle, shown as ω inFIG.3A.

Additionally, as shown inFIGS.3B-3D, the magnetic position sensor10includes a magnet60substantially similar to that of magnet12. A third magnetic sensor64and fourth magnetic sensor66function similar to that of the first magnetic sensor30and the second magnetic sensor32, respectfully. The magnet60may be configured to travel along the center axis74, similar to that of center axis24.

In some embodiments, the third magnetic sensor64and the curved track62are substantially stationary as the magnet60moves across the curved track62. For example, the third magnetic sensor64may be coupled to the curved track62. In some embodiments, the magnet60, and the coupled fourth magnetic sensor66, are substantially stationary as the curved track62moves between the magnet60and the fourth magnetic sensor66. In some embodiments, only the third magnetic sensor64is utilized by or present within the magnetic position sensor10. In other embodiments, only the fourth magnetic sensor66is utilized by or present within the magnetic position sensor10. In some embodiments, both the third magnetic position sensor64and the fourth magnetic position sensor66are utilized by or present within the magnetic position sensor10. For example, the third magnetic position sensor64may be station as the fourth magnetic position sensor66and the magnet60move along the track62.

FIG.4illustrates the magnetic flux experienced by the curved track62as the magnet60moves relative to the curved track62. For example, in image400, the magnet60is situated at approximately a position P11, or at the first end70aand the third end70bof the first curved magnetic rod62aand the second curved magnetic rod62b(e.g., the beginning of the curved track62), respectfully. At position P11, the magnetic field is strongest at the beginning of the curved track62. Accordingly, in this position, the third magnetic sensor64and the fourth magnetic sensor66experience the greatest magnetic flux relative to positions P12and P13.

In image402, the magnet60is situated at a position P12, or approximately ½ of the way across the curved track62. In position P12, the magnetic field has decreased at the beginning of the curved track62. Accordingly, the third magnetic sensor64experiences less magnetic flux (for example, a medium level of magnetic flux). In some embodiments, the fourth magnetic sensor66travels with the magnet60. Although the fourth magnetic sensor66continues to experience a high amount of magnetic flux, the increase in the size of the curved gap68impacts the direction of the magnetic field. Accordingly, the fourth magnetic sensor66experiences a greater change in magnetic flux relative to position P11.

In image404, the magnet60is at a position P13, situated fully across or along the curved track62at approximately the second end72aof the first curved magnetic rod62aand the fourth end72bof the second curved magnetic rod62b(e.g., the end of the curved track62). Accordingly, the third magnetic sensor64experiences even less magnetic flux (for example, a low level of magnetic flux) relative to position P12. In some embodiments, the fourth magnetic sensor66, also now situated at the end of the curved track62, experiences a greatest change in magnetic flux relate to positions P11, P12and P13due to the increased size of the curved gap68.

In some embodiments, the material of the tracks14and62impacts the magnetic field of the magnets12and60and, therefore, impacts the magnetic flux experienced by the magnetic sensors30,32,64, and66. For example, Mu-metal has a high permeability in comparison to AISI steel 1010, more generally referred to as carbon steel. The different permeability allows for different re-direction of the magnetic flux density of the magnet12,60. High permeability, for example, attracts more flux density, resulting in more magnetic flux being concentrated in the path formed by the track14,62. A lower permeability, for comparison, attracts less magnetic field and instead acts similarly to a magnet itself.FIGS.5A-Billustrate graphs showing the magnetic flux experienced by the first magnetic sensor30. InFIG.5A, the track14is composed of Mu-metal. InFIG.5B, the track14is composed of AISI steel 1010.FIG.5Cillustrates a graph showing the magnetic flux experienced by the third magnetic sensor64when the track62is composed of at least one selected from a group consisting AISI steel 1010, pure iron, and Mu-metal. Accordingly, the material of the track14,62may be accounted for when implementing the magnetic position sensor10.

It should be understood that the angle θ can be chosen or selected for the particular application of the sensor. In some embodiments, the angle θ between the first magnetic rod14aand the second magnetic rod14bimpacts the magnetic field of the magnet12. Therefore, the angle θ impacts the magnetic flux experienced by the magnetic sensors30,32. Similarly, in some embodiments, the angle ω between the first curved magnetic rod62aand the second curved magnetic rod62bimpacts the magnetic field of the magnet60. Therefore, the angle ω impacts the magnetic flux experienced by the magnetic sensors64,66. If the chosen angle θ or co is too small (for example, 0.5 degrees), the respective magnetic rods in the tracks14,62may experience a magnetic field exchange, reducing the amount of flux density experienced by the respective magnetic sensors30,32,64,66. Accordingly, the angle θ or ω may be chosen such that the magnets12,60generate the desired magnetic flux density.

FIG.6illustrates a block diagram of a system600incorporating the magnetic position sensor10, according to some embodiments. In the example shown, the system600includes a temperature sensor602and an electronic controller604configured to receive signals from the magnetic position sensor10and the temperature sensor602. The magnetic position sensor10is configured to send one or more magnetic position signals indicative of the position (e.g., the location) of the magnet12,60to the electronic controller604. The temperature sensor602is configured to send one or more temperature signals to the electronic controller504based on at least one selected from a group consisting of an ambient temperature and a temperature of the track14,62. In some embodiments, the electronic controller604may output an output signal based on the one or more temperature signals and one or more magnetic position signals received from the magnetic position sensor10to an external device. In some embodiments, the electronic controller604may output system software and hardware diagnostic fault codes to an external device. The diagnostic fault codes may be transmitted separately-from or along with magnetic position signals from the magnetic position sensor10and temperature signals from the temperature sensor602. In some embodiments, the magnetic position sensor10transmits one or more magnetic position signals, with or without embedded diagnostic fault code, to the external device directly.

FIG.7illustrates a block diagram of an electronic controller604(e.g., a computer, a microcontroller, a microprocessor, an electronic processor, or similar device or group of devices). In the embodiment illustrated, the electronic controller604includes an electronic processor700, a memory708, input devices710, and output devices712. The electronic processor700, the memory708, the input devices710, and the output devices712, as well as various modules or circuits connected to the electronic controller604, are connected by one or more control and/or data buses. The memory708includes a program storage area and a data storage area. The program storage area and the data storage area can include combinations of different types of memory708, 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 devices. The electronic processor700is connected to the memory708and executes software instructions that are capable of being stored in a RAM of the memory708(e.g., during execution), a ROM of the memory708(e.g., on a generally permanent basis), or another non-transitory computer readable medium. Software included for the processes and methods for the system600can be stored in the memory708of the electronic controller604. The software can include firmware, one or more applications, program data, filters, rules, one or more program modules, and other executable instructions. The electronic controller604is configured to retrieve from memory708and execute, among other things, instructions related to the control processes and methods described herein. In other constructions, the electronic controller604includes additional, fewer, or different components.

Electrical and (electro)-magnetic characteristics (e.g., permeability) of components of the magnetic position sensor10, for example, the tracks14and62may be dependent on the temperature. Accordingly, the magnetic flux experienced by the magnetic sensors30,32,64, and66may also be dependent on the temperature. In some embodiments, the electronic controller604is configured to determine the position of the magnet12,60based on one or more magnetic position signals and on the one or more temperature signals.

FIG.8, for example, illustrates a block diagram of a method800performed by the electronic controller604for determining the position of the magnet. At block802, the electronic controller604receives one or more magnetic position signals from the magnetic position sensor10. The one or more magnetic position signals may be, for example, the magnetic flux experienced by the first magnetic sensor30, the second magnetic sensor32, or a combination of the first magnetic sensor30and the second magnetic sensor32. In some embodiments, the one or more magnetic position signals may represent the magnetic flux experienced by the third magnetic sensor64, the fourth magnetic sensor66, or a combination of the third magnetic sensor64and the fourth magnetic sensor66.

At block804, the electronic controller604receives one or more temperature signals from the temperature sensor602. The temperature signals may represent the ambient temperature, the temperature of a component of the magnetic position sensor10(such as the track14,62), or a combination of the ambient temperature and the temperature of a component of the magnetic position sensor10. At block806, the electronic controller604determines a position of the magnet12,60based on the one or more magnetic position signals and the one or more temperature signals. In some embodiments, the electronic controller604transmits the position of the magnet12,60to an external device. Prior to transmission, the position of the magnet12,60may be conditioned using a filter (for example, a low-pass filter, a high-pass filter, or the like), may be converted to a digital format, or the like. In some embodiments, a linearization of the output signal may be performed by the magnetic sensor10, the electronic controller604, or some combination thereof prior to transmission to the external device.

Water Level Sensor Example

Water level detection is one of many applications for the magnetic position sensor10. In one example, a water tank includes four potential levels of water (e.g., level 1, level 2, level 3, and level 4). In some embodiments, level 1 is a low level (¼) of water, level 2 if a medium level of water (½), level 3 is a high level of water (¾), and level 4 is a full tank (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 and exit the reservoir. The magnetic position sensor10may be, for example, attached to a side of the reservoir, such that the first end18aand the third end18bare situated at the bottom of the reservoir, and such that the second end20aand the fourth end20bare situated at the top of the reservoir. Additionally, the magnet12is connected to or otherwise incorporated in a buoyant float such that the physical position of the magnet12corresponds to the physical level of a top surface of the water contained within the reservoir.

Referring toFIG.2, when the reservoir is at a water level of level 1, the magnetic flux experienced by the magnetic position sensor10may be, for example, the magnetic flux shown by image200. When the reservoir is at a water level of level 2, the magnetic flux experienced by the magnetic position sensor10may be, for example, the magnetic flux shown by image202. When the reservoir is at a water level of level 3, the magnetic flux experienced by the magnetic position sensor10may be, for example, the magnetic flux shown by image204. When the reservoir is at a water level of level 4, the magnetic flux experienced by the magnetic position sensor10may be, for example, the magnetic flux shown by image206.

The electronic controller604receives one or more magnetic position signals from the magnetic position sensor10. In some embodiments, the electronic controller604also receives one or more temperature signals indicative of the temperature of the water from the temperature sensor602. Based on the one or more magnetic position signals and the one or more temperature signals, the electronic controller604determines the level of the water stored within the reservoir of the water tank.

Thus, embodiments provide, among other things, a magnetic position sensor. Various features and advantages are set forth in the following claims.