Off-axis magnetic angle sensor using a magnetic sensing probe and a multi-pole magnet array

Abstract

Apparatus and associated methods relate to measuring the position and displacement of a 2D surface magnet array of at least three adjacent magnetic north-south tracks that are at an acute angle to their motion displacement relative to a magnetic field sensor (e.g., a magnetic sensing probe). In an illustrative example, the geometry of the 2D surface magnet array can be planar with adjacent and alternating north and south pole regions. In some embodiments, the 2D surface magnet array geometry can take the form of: (1) an axial cylindrical spiral multipole magnet array having individually magnetized layers oriented in a spiral shape, or (2) a radial disk-shaped spiral multipole magnet array having at least three adjacent north-south tracks oriented in a spiral shape.

Description

[0001] This application is a divisional application of the Chinese patent application entitled “Off-axis magnetic angle sensor using magnetic sensing probe and multi-pole magnet array” and application number 201880055687.5 filed on February 27, 2020. Technical Field

[0002] Various embodiments generally relate to motion detection using magnetic field sensors. Background Art

[0003] The control of a multi-pole electric motor can depend on sine and cosine signals with a 90-degree phase shift, with one sine and cosine period per electrical cycle. These sine and cosine signals can be generated by a resolver mounted on the rotating shaft of the electric motor. A resolver is a rotating electrical transformer used to measure rotation. A resolver can be an analog sensing element used in a control system that controls the rotational angular position and / or speed of a motor. Resolvers can be used to measure the rotational angular position of mechanical and electrical components in a variety of applications, including computer numerical control (CNC) machines, robotics and papermaking machines, and thermal or electric motors in transportation vehicles.

[0004] A rotary encoder is an electromechanical device that converts the angular position or motion of a shaft or axle into an analog or digital signal. Rotary encoders can be used in applications requiring precise shaft monitoring (sometimes with infinite rotation), such as industrial control, robotics, and rotary radar platforms. Rotary encoders can be either absolute or incremental.

[0005] Magnetic field sensors are electronic components that measure magnetic fields. They can be used in proximity switches, positioning, speed detection, and current sensing applications. They can also be used to time wheel and axle speeds, such as in internal combustion engine ignition timing, tachometers, and anti-lock braking systems. Types of magnetic field sensors include Hall effect sensors, AMR / GMR magnetometers, magnetoresistive sensors, and TMR sensors. Summary of the Invention

[0006] Apparatus and associated methods relate to measuring the position and displacement of a 2D surface magnet array of at least three adjacent magnetic north-south tracks that are at an acute angle to their motion displacement relative to a magnetic field sensor (e.g., a magnetic sensing probe). In an illustrative example, the geometry of the 2D surface magnet array can be planar with adjacent and alternating north and south pole regions. In some embodiments, the 2D surface magnet array geometry can take the form of: (1) an axial cylindrical spiral multipole magnet array with individually magnetized layers oriented in a spiral shape, or (2) a radial disk-shaped spiral multipole magnet array with at least three adjacent north-south tracks oriented in a spiral shape.

[0007] Various embodiments can achieve one or more advantages. For example, some embodiments can be suitable for use in a wide variety of mechanical, electronic, industrial, and commercial applications. In some examples, the magnet array and magnetic field sensor can be a cheaper, smaller, and lighter alternative to (and serve as a replacement for) a rotary transformer. For example, some embodiments can increase the compactness of a control motor and reduce the weight of the motor. Some embodiments can include sensors that are backward compatible solutions for rotary transformers and can provide the same type of output as a rotary transformer, but based on a low-cost, highly integrated magnetic field sensor design and an associated tilt-angle multi-pole magnetic ring rotating target.

[0008] In various embodiments, the magnet array and magnetic field sensor can provide a compensation mechanism to measure and remove any misalignment errors associated with mechanical stack tolerances or aging. In various examples, the magnet array can be customized to match the electrical phase cycle of the electric motor, allowing the magnet array and magnetic field sensor to replace a wide variety of old, damaged, or obsolete rotation measurement equipment.

[0009] An advantage of some embodiments can be a magnetic field angle sensor configured to generate analog sine and cosine outputs with a 90-degree phase shift from two magnetic probes (such as an MR bridge) sensing the displacement of a multi-pole annular magnet array having a pole width w and tilted at a specific angle θ to produce N sine and cosine cycles for every 360-degree rotation. The magnet array with a specific tilt angle can advantageously allow for customized periodic output of the magnetic field sensor to control an electric motor with N poles (e.g., motor rotation speed). This solution can result in a sensor output with a specific period that matches the resolver output.

[0010] The details of various embodiments are set forth in the accompanying drawings and the description that follows. Other features and advantages will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 Depicted is a perspective view of an exemplary brushless DC electric motor with an exemplary rotation measurement system.

[0012] Figure 2 Depicted is a perspective view of an exemplary axial cylindrical spiral multipole magnet array having three adjacent inclined tracks, and an exemplary magnetic field sensor.

[0013] Figure 3 Depicted is a perspective view of an exemplary 2D surface multipole magnet track having alternating north and south poles having the same width w.

[0014] Figure 4A、 Figure 4B and Figure 4C Depicted are exemplary axial cylindrical spiral multipole magnet arrays having varying pitches, and a perspective view of an exemplary magnetic field sensor.

[0015] Figure 5A 、 Figure 5B and 5C Depicted are an exemplary planar multi-pole magnet array of length L, in which three adjacent tilted magnetic tracks have different pitches, and a perspective view of an exemplary magnetic field sensor.

[0016] Figure 6A and Figure 6B Depicts a cross-sectional view of an exemplary motor shaft having radial bearings disposed between the shaft and an exemplary magnetic field sensor. Figure 6A An exemplary axial cylindrical multipole magnet array in which three adjacent magnetic north-south tracks have an inclined angle is maintained in Figure 6B A radial disk multipole magnet array is maintained in which three adjacent magnetic north-south tracks have an inclined angle.

[0017] Figure 7 Depicted is a perspective view of an exemplary radial disk multipole magnet array in which three adjacent magnetic north-south tracks have a tilt angle such that the adjacent magnetic north-south tracks are oriented in a spiral shape.

[0018] Figure 8A and Figure 8B Depicts a plan view of an exemplary radial disk multipole magnet array in which three adjacent magnetic north-south tracks have an inclination angle such that the adjacent magnetic north-south tracks are oriented in a spiral shape, and an exemplary magnetic field sensor, the radial disk also having Figure 8A The outer concentric North and South Poles and Figure 8B The inner concentric North and South Poles in.

[0019] Figure 8C Depicts an exemplary axial cylindrical spiral multipole magnet array and an exemplary magnetic field sensor (similar to Figure 2 and Figures 4A-4C ), an axial cylindrical spiral multipole magnet array also having stacked north and south poles and an exemplary magnetic field sensor.

[0020] Figure 8D Depicts an exemplary planar multipole magnet array (similar to Figures 5A-5C ) and a perspective view of an exemplary magnetic field sensor, a planar multipole magnet array also having adjacent straight and angled magnetic track portions.

[0021] Figure 9 Depicted is an exemplary radial disk multipole magnet array in which three adjacent magnetic north-south tracks have tilted angles (similar to Figure 7), adjacent magnetic north-south tracks are oriented in a spiral shape and have different degrees of spiraling.

[0022] Figure 10 Depicted are a cross-sectional view of an exemplary power steering system and a block diagram of an exemplary power steering monitoring and control system.

[0023] Like reference symbols in the various drawings indicate like elements. DETAILED DESCRIPTION

[0024] Figure 1 A perspective view of an exemplary brushless DC electric motor with an exemplary rotation measurement system is depicted. Exemplary brushless DC electric motor 100 is shown having a rotor core 105. Rotor core 105 rotates in response to a varying magnetic field applied by a stator (not shown). As rotor core 105 rotates, shaft 110 rotates with it. Affixed to shaft 110 is an (axial) cylindrical magnet 115, which rotates at the same rotational speed as shaft 110. Cylindrical magnet 115 has regions of varying magnetic polarity, such that as cylindrical magnet 115 rotates, it generates a varying magnetic field. This varying magnetic field is measured by at least one magnetic field sensor 120 (e.g., a magnetic sensing probe). At least one magnetic field sensor 120 is coupled to a motion control system 125 via electrical connection 130. For example, the magnetic field sensor may include at least one magnetic sensing probe 120A for measuring angular position and displacement, and at least one magnetic sensing probe 120B for measuring axial position variations due to axial stacking tolerances and compensating for errors introduced thereby. The instantaneous magnetic field at the at least one magnetic field sensor 120 is converted into an electrical signal, which the at least one magnetic field sensor 120 transmits to the motion control system 125 via electrical connection 130. The motion control system 125 includes circuitry configured to control the rotation of the rotor core 105 based on the electrical signal received from the at least one magnetic field sensor 120.

[0025] Motion control system 125 may include a programmable logic controller (PLC) having specific circuit logic designed to control the rotation of rotor core 105. In some examples, motion control system 125 may be coupled to a stator (not shown) coupled to rotor 105. In such examples, motion control system 125 may control the energization and de-energization of electromagnets in the stator. The electrical signals received by motion control system 125 from at least one magnetic field sensor 120 may allow motion control system 125 to accurately time the energization and de-energization of the electromagnets in the stator to achieve smooth rotation of rotor core 105 and shaft 110.

[0026] Figure 2An exemplary axial cylindrical spiral multipole magnet array having three adjacent inclined tracks and a perspective view of an exemplary magnetic field sensor are depicted. The axial cylindrical spiral multipole magnet array 200 is shown having a central axis 205. When, for example, the axial cylindrical spiral multipole magnet array 200 is attached to a rotating shaft (e.g., Figure 1 When the axial cylindrical spiral multipole magnet array 200 is rotated about the central axis 205 (the axis of rotation of the magnet array 200 is axially aligned with the axis 110), the cylindrical spiral multipole magnet array 200 can be rotated about the central axis 205. The cylindrical spiral multipole magnet array 200 includes three adjacent magnetized layers. These magnetized layers include a north magnetized layer 210 and a south magnetized layer 215 adjacent to each other and having a fixed width w. The magnetized layers 210 and 215 are wound in a spiral manner at a constant tilt angle within the cylindrical spiral multipole magnet array 200. The magnetized layers 210 and 215 are wound about the central axis 205 so that the magnetized layers are spaced apart about the central axis 705 according to a radial angle α about the central axis 205 and a distance d along the central axis 205. z The widthwise midpoint of each magnetic layer is arranged monotonically (e.g., positioned or distributed in a circular spiral / helicoidal configuration with a constant magnitude slope). In other words, the ...) as a function of the radial angle α about the central axis 205 (e.g., moving from 0° to 360°) and the distance d along the central axis 205. z At the magnetic discontinuity 220 , the layers switch polarity but continue to coil within the cylindrical spiral multipole magnet array 200 .

[0027] The magnetic field sensor 225 is located on the outer periphery of the axial cylindrical spiral multipole magnet array 200. The magnetic field sensor 225 is configured to output an electrical signal as a function of the local magnetic field around the magnetic field sensor 225. When the cylindrical spiral multipole magnet array 200 rotates about the central axis 205, the magnetic field around the magnetic field sensor (e.g., B x and B y ) varies due to the helical nature of the magnetized layers 210 and 215. The exact output signal of the magnetic field sensor 225 according to the rotation of the cylindrical spiral multipole magnet array 200 will be described in further detail in the following paragraphs.

[0028] In some examples, the cylindrical spiral multipole magnet array 200 may not have magnetic discontinuities 220. In various embodiments, the spiral windings in the cylindrical spiral multipole magnet array 200 may have a magnetic discontinuity of 220. Figure 2 The exemplary embodiment shown has a larger or smaller pitch.The pitch of the cylindrical spiral multipole magnet array 200 can be customized to determine the exact period of the sine / cosine signals output by the magnetic field sensor 225 when the cylindrical spiral multipole magnet array 200 rotates at a constant angular velocity.

[0029] Figure 3A perspective view of an exemplary 2D surface multipole magnet track with alternating north and south poles having the same width w is depicted. Multipole magnet track 300 is planar in shape and includes north poles 305 and south poles 310 adjacent to each other. The alternating north poles 305 and south poles 310 generate magnetic field lines 315 that originate from the north poles 305 and terminate at the south poles 310. Near the center of each pole 305 and 310, the magnetic field lines 315 are substantially orthogonal to the plane defined by multipole magnet track 300. For example, near the center of the north pole 305, the magnetic field lines 315 point upward and perpendicular to the plane of the multipole magnet track 300. Near the center of the south pole 310, the magnetic field lines point downward and perpendicular to the plane of the multipole magnet track 300.

[0030] Magnetic field sensor 320 is positioned above multipole magnet track 300. The distance between magnetic field sensor 320 and multipole magnet track 300 defines an air gap 325. Magnetic field sensor 320 travels along a path 330 relative to multipole magnet track 300. Coordinate axes 335 are defined relative to multipole magnet track 300, where the x-axis is defined by left-right movement relative to multipole magnet track 300, the y-axis is defined by front-back movement relative to multipole magnet track 300, and the z-axis is defined by up-and-down movement relative to multipole magnet track 300. Path 330 of magnetic field sensor 320 remains constant along the z-axis, but it moves along the x- and y-axes. More specifically, path 330 of magnetic field sensor 320 is a substantially straight line that lies in a plane defined by the x- and y-axes for a constant z-value above multipole magnet track 300. The line of path 330 forms an angle θ 340 relative to the x-axis. The relative constant movement of the magnetic field sensor 320 along the path 330 relative to the multi-pole magnet track 300 results in a sinusoidal signal 345 output by the magnetic field sensor 320. The period P of the sinusoidal signal 345 is θ It depends in part on the period p of the pattern of north pole 305 and south pole 310 relative to their width w, and the angle θ 340 of path 330 relative to the x-axis:

[0031]

[0032] Although the details of a planar multipole magnet track 300 have been described, the same details can also be applied to axial cylindrical magnets (e.g., axial cylindrical spiral multipole magnet array 200, Figure 2) on a track. For example, the relative path of the magnetic field sensor 225 relative to the rotating cylindrical spiral multipole magnet array 200 can be similar to the relative path 330 of the magnetic field sensor 320 relative to the multipole magnet track 300. This is because the local topology of the outer surface of the cylindrical spiral multipole magnet array 200 is similar to the topology of the planar multipole magnet track 300. In this case, the angle of travel of the magnetic field sensor 225 relative to the adjacent north pole layer 210 and south pole layer 215 of the rotating cylindrical spiral multipole magnet array 200 can be determined by the pitch of the spiral. A spiral with a small pitch can correspond to a smaller angle θ340, while a spiral with a larger pitch can correspond to a larger angle θ340. Similarly, the same details of the planar multipole magnet track 300 can be applied to Figure 7 A radially spiraling disk multipole magnet array is shown (described in depth below).

[0033] In some examples, when Figure 3 When the magnetic pole pattern shown is formed (for example, there are three cycles for every 360-degree rotation of the ring magnet), the magnetic field can be projected into the xz plane and the yz plane. When the magnetic field sensor is located in the xz plane, the magnetic field sensor may be sensitive only to the magnetic field projected into the xz plane. In this way, the sinusoidal shape of the signal output from the magnetic field sensor can maintain its shape when the magnetic field sensor moves from the north pole to the south pole (because the magnetic field sensor may be insensitive to the direction of the magnetic field and may be insensitive to magnetic fields located in the yz plane).

[0034] Figure 4A 、 Figure 4B and Figure 4C Depicted are perspective views of exemplary axial cylindrical spiral multipole magnet arrays having varying pitches. Figure 4A As shown, the first axial cylindrical spiral multi-pole magnet array 400a with a radius R has a spiral pitch angle θ a 405a (between 0 and 90 degrees) and three adjacent magnetic poles with a constant pole width w 410a. Magnetic field sensor 415a is located near the outer surface of first cylindrical spiral multipole magnet array 400a. When first cylindrical spiral multipole magnet array 400a rotates at a constant angular velocity about its central axis, the changing magnetic field around magnetic field sensor 415a is converted into a sinusoidal electrical signal 420a. In this example, the helical pitch angle θ is a 405a is adjusted to generate one period P of the sinusoidal electrical signal 420a for every 360 degree rotation of the first cylindrical spiral multi-pole magnet array 400a. The angle θ that will generate one period P is a It is given by:

[0035]

[0036] like Figure 4B As shown, the second axial cylindrical spiral multi-pole magnet array 400b has a spiral pitch angle θ b 405b (between 0 and 90 degrees) and three adjacent poles with a constant pole width w 410b. Helical pitch angle θ b 405b is greater than the helical pitch angle θ a 405a. A magnetic field sensor 415b is located near the outer surface of a second cylindrical spiral multipole magnet array 400b having a radius R. When the second cylindrical spiral multipole magnet array 400b rotates at a constant angular velocity about its central axis, the changing magnetic field around the magnetic field sensor 415b is converted into a sinusoidal electrical signal 420b. In this example, the helical pitch angle θ is b 405b is adjusted to generate two cycles P of the sinusoidal electrical signal 420b for every 360 degree rotation of the second cylindrical spiral multi-pole magnet array 400b. The angle θ that will generate the two cycles P is b It is given by:

[0037]

[0038] like Figure 4C As shown, the third axial cylindrical spiral multi-pole magnet array 400c has a spiral pitch angle θ c 405c (between 0 and 90 degrees) and three adjacent poles with a constant pole width w 410c. Helical pitch angle θ c 405c is greater than the helical pitch angle θ b 405b. A magnetic field sensor 415c is located near the outer surface of a third cylindrical spiral multipole magnet array 400c having a radius R. When the third cylindrical spiral multipole magnet array 400c rotates at a constant angular velocity about its central axis, the changing magnetic field around the magnetic field sensor 415c is converted into a sinusoidal electrical signal 420c. In this example, the helical pitch angle θ is c 405c is adjusted to generate three cycles P of the sinusoidal electrical signal 420c for every 360 degree rotation of the third cylindrical spiral multi-pole magnet array 400c. The angle θ at which the three cycles P will be generated is c It is given by:

[0039]

[0040] More generally, in various embodiments, the pitch angle or tilt angle of the cylindrical multi-pole magnet array can be specifically adjusted to produce N cycles for each rotation of the cylindrical multi-pole magnet array. NFor generating N cycles P of a sinusoidal electrical signal for every 360 degree rotation of a cylindrical spiral multi-pole magnet array having three adjacent poles with a constant pole width w. The angle θ at which the N cycles P will be generated N It is given by:

[0041]

[0042] This can allow the replacement of resolvers used to control N-pole electric motors. Additionally, the pitch angle or tilt angle can be adjusted to produce N cycles for each rotation of the ring magnet so that an effective off-axis angle sensor (or linear sensor) can obtain absolute position measurements within each of these N cycles.

[0043] In some examples, around Figures 4A-4C The dashed line surrounding the cylindrical spiral multipole magnet array in FIG. 1 can represent the relative displacement of the magnetic field sensor relative to the cylindrical spiral multipole magnet array. For example, as the cylindrical spiral multipole magnet array rotates about its central axis, the magnetic field sensor can measure the magnetic field in the local vicinity of the dashed line. Due to the non-zero pitch angle of the spiral magnetic layers of the cylindrical spiral multipole magnet array, this magnetic field can vary sinusoidally. This can cause the magnetic field sensor to generate an output signal having a specific number of cycles for each rotation of the cylindrical spiral multipole magnet array.

[0044] Figure 5A 、 Figure 5B and 5C Depicted is a perspective view of an exemplary planar multipole magnet array having a length L, wherein three adjacent tilted magnetic tracks have different pitches per unit length L, and an exemplary magnetic field sensor. Figure 5A As shown, the first planar multi-pole magnet array 500a having three adjacent inclined magnetic tracks has an inclination angle θ d 505a (between 0 and 90 degrees) and the magnetic pole width w 510a. The magnetic field sensor 515a is located near the top surface of the first planar multi-pole magnet array 500a. When the magnetic field sensor 515a moves at a constant speed relative to the top surface of the first planar multi-pole magnet array 500a, the changing magnetic field around the magnetic field sensor 515a is converted into a sinusoidal electrical signal 520a. In this example, the tilt angle θ d 505a is adjusted to generate one period P of the sinusoidal electrical signal 520a per unit length L 525a of the first planar multi-pole magnet array 500a. The angle θ that will generate one period P is d It is given by:

[0045]

[0046] like Figure 5BAs shown, the second planar multi-pole magnet array 500b having three adjacent inclined magnetic tracks has an inclination angle θ e 505b (between 0 and 90 degrees) and the pole width w 510b. Inclination angle θ e 505b is greater than the tilt angle θ d 505a. Magnetic field sensor 515b is located near the top surface of second planar multi-pole magnet array 500b. When magnetic field sensor 515b moves at a constant speed relative to the top surface of second planar multi-pole magnet array 500b, the changing magnetic field around magnetic field sensor 515b is converted into a sinusoidal electrical signal 520b. In this example, the tilt angle θ e 505b is adjusted to generate two periods P of the sinusoidal electrical signal 520b per unit length L 525b of the second planar multi-pole magnet array 500b. The angle θ that will generate the two periods P is e It is given by:

[0047]

[0048] like Figure 5C As shown, the third planar multi-pole magnet array 500c having three adjacent inclined magnetic tracks has an inclination angle θ f 505c (between 0 and 90 degrees) and the pole width w 510c. Inclination angle θ f 505c is greater than the tilt angle θ e 505b. Magnetic field sensor 515c is located near the top surface of third planar multi-pole magnet array 500c. When magnetic field sensor 515c moves at a constant speed relative to the top surface of third planar multi-pole magnet array 500c, the changing magnetic field around magnetic field sensor 515c is converted into a sinusoidal electrical signal 520c. In this example, the tilt angle θ f 505c is adjusted to generate three periods P of the sinusoidal electrical signal 520c per unit length L 525c of the third planar multipole magnet array 500c. The angle θ that will generate the three periods P is f It is given by:

[0049]

[0050] More generally, in various embodiments, the pitch angle or tilt angle of a planar multipole magnet array having a length L can be specifically adjusted to produce M periods per unit length L of the 2D planar magnet array. M For generating M periods P of a sinusoidal electrical signal per unit length L of a planar multi-pole magnet array having three adjacent poles with a constant pole width w. The angle θ at which the M periods P will be generated M It is given by:

[0051]

[0052] Figure 6A and Figure 6B Depicts a cross-sectional view of an exemplary motor shaft with radial bearings, and exemplary magnetic field sensors in two cases. Figure 6A An exemplary axial cylindrical multipole magnet array in which three adjacent magnetic north-south tracks have an inclined angle is maintained in Figure 6B A radial disk multipole magnet array is maintained in which three adjacent magnetic north-south tracks have an inclined angle. The motor shaft assembly portion 600 includes a motor shaft 605 and a bearing 610 coupled (e.g., press-fit) to the motor shaft 605. The bearing 610 includes an inner race 615 and an outer race 620. A cylindrical multipole magnet array 625a / 625b is fixedly coupled (e.g., press-fit) to the outer surface of the inner race 615. When the shaft 605 rotates relative to the outer race 620, the inner race 615 and the cylindrical multipole magnet array 625a / 625b rotate with the shaft 605 (relative to the outer race 620). If the shaft is fixed and the outer race 620 rotates, then 630a and 630b can be transposed.

[0053] exist Figure 6A In the exemplary embodiment of the present invention, a magnetic field sensor 630a is fixedly coupled to the inner surface of the outer race 620 at a position near the outer surface of a cylindrical spiral (axial) multi-pole magnet array 625a, which is fixedly coupled to the outer surface of the inner race 615 of the bearing 610. Due to the relative rotation of the cylindrical spiral multi-pole magnet array 625a, the relative rotation between the inner race 615 and the outer race 620 causes a changing magnetic field at the magnetic field sensor 630a. This changing magnetic field at the magnetic field sensor 630a is converted into an electrical signal, which can be used to measure the rotational displacement, speed, and direction of the shaft 605 relative to the outer race 620.

[0054] exist Figure 6B In the exemplary embodiment of FIG. 5 , magnetic field sensor 630 b is fixedly coupled to the inner surface of outer race 620 of bearing 610 at a position proximate to the side surface of disk-shaped spiral (radial) multi-pole magnet array 625 b, which is fixedly coupled to the outer surface of inner race 615 of bearing 610 (e.g., see FIG. 5 ). Figure 7 and Figure 9 Due to the relative rotation of the disk-shaped spiral multi-pole magnet array 625b, the relative rotation between the inner race 615 and the outer race 620 causes a changing magnetic field at the magnetic field sensor 630b. This changing magnetic field at the magnetic field sensor 630b is converted into an electrical signal that can be used to measure the rotational position, displacement, speed, and direction of the shaft 605 relative to the outer race 620.

[0055] In some examples, a multi-pole magnet array system can be embedded in a bearing mounted directly to a motor, which can be an electric motor. For example, the multi-pole magnet array can be attached to the inner race or outer race of the bearing. Additionally, a magnetic field sensor can also be attached to the inner race or outer race of the bearing. The multi-pole magnet array and the magnetic field sensor can be located on different bearings, allowing the multi-pole magnet array system to be used to measure relative rotation between the bearings.

[0056] Figure 7 A perspective view of an exemplary radial disk multipole magnet array is depicted in which adjacent magnetic north-south tracks have an inclination angle such that the adjacent magnetic north-south tracks are oriented in a spiral shape. The radial disk multipole magnet array 700 is shown shaded to indicate the north-south polarity of the tracks of the magnetic field. The radial disk multipole magnet array 700 has a central axis 705 about which the radial disk multipole magnet array 700 can rotate. The radial disk multipole magnet array 700 is formed by a north pole layer 710 and a south pole layer 715. The north pole layer 710 and the south pole layer 715 spiral inward toward the central axis 705 (e.g., each layer has a radius R relative to the central axis 705). l The radial angle α of the magnetic layers of the radial disk multipole magnet array 700 is monotonically increasing (clockwise) or decreasing (counterclockwise). In this sense, the magnetic layers of the radial disk multipole magnet array 700 are wound about the central axis 705 such that the layers are monotonically arranged (e.g., located or positioned in an outward spiral) about the central axis 705 according to the radial angle α about the central axis 705. In other words, the radial widthwise midpoint of each magnetic layer is monotonically distributed according to the radial angle α about the central axis 705. Each north layer 710 is adjacent to a corresponding south layer 715 such that the layers alternate with increasing radial distance from the central axis 705. At the magnetic discontinuity 720, the layers switch polarity but continue to spiral within the radial disk multipole magnet array 700.

[0057] Figure 8A and Figure 8B Depicts a plan view of an exemplary radial disk multipole magnet array in which three adjacent magnetic north-south tracks have an inclination angle such that the adjacent magnetic north-south tracks are oriented in a spiral shape, and an exemplary magnetic field sensor, the radial disk also having Figure 8A The outer concentric North and South Poles and Figure 8B The inner concentric North and South Poles in. Figure 8AA first radial disk multipole magnet array 800a is depicted, comprising three adjacent inclined spiral tracks within a spiral magnetic layer portion 805a. Bounding spiral magnetic layer portion 805a are concentric north-south pole track portions 810a. In contrast to spiral magnetic layer portion 805a, concentric north-south pole layer portions 810a do not have a spiral form, but instead form concentric circles around the outer perimeter of first radial disk multipole magnet array 800a. These two concentric tracks can be used to monitor and compensate for measurement errors caused by radial displacement due to stacking tolerances and aging.

[0058] Angular magnetic field sensor 815a is located above the top surface of spiral magnetic layer portion 805a. Angular magnetic field sensor 815a detects changes in the magnetic field as first-disk radial multipole magnet array 800a rotates about its central axis. Off-axis misaligned magnetic field sensor 820a is located above the top surface of concentric north and south pole layer portion 810a. Off-axis misaligned magnetic field sensor 820a is used to detect and compensate for off-axis rotation / oscillation / movement of first-disk radial multipole magnet array 800a.

[0059] Figure 8B A second radial multipole magnetic disk array 800b is depicted, which includes a spiral magnetic layer portion 805b. Within the spiral magnetic layer portion 805b are concentric north and south pole layer portions 810b. In contrast to the spiral magnetic track portion 805b, the concentric north and south pole layer portions 810b do not have a spiral form, but rather form concentric circles on the inner periphery of the second radial multipole magnet array 800b.

[0060] Angular magnetic field sensor 815b is located above and in the middle of the top surface of spiral magnetic layer portion 805b, while off-axis misaligned magnetic field sensor 820b is located above the top surface of concentric north and south pole layer portion 810b. These sensors 815b and 820b have similar functions as sensors 815a and 820a discussed above (e.g., for correcting output signals to compensate for off-axis misalignment).

[0061] Figure 8C Depicts an exemplary axial cylindrical spiral multipole magnet array and an exemplary magnetic field sensor (similar to Figure 2 and Figures 4A-4C ), the axial cylindrical spiral multipole magnet array also has stacked north and south poles. Axial cylindrical spiral multipole magnet array 800c includes a spiral magnetic layer portion 805c. Below spiral magnetic layer portion 805c is a stacked north and south pole layer portion 810c. Compared to spiral magnetic layer portion 805c, stacked north and south pole layer portions 810c do not have a spiral form, but instead form a stacked circle / cylinder at the bottom of cylindrical spiral multipole magnet array 800c.

[0062] Angular magnetic field sensor 815c is positioned adjacent to a side surface of the spiral magnetic layer portion 805c and in the middle of three adjacent magnetic tracks, while off-axis misalignment magnetic field sensor 820c is positioned adjacent to a side surface of the stacked north and south magnetic pole layers and in the middle of north and south track portion 810c. These sensors 815c and 820c have similar functions as sensors 815a and 820a discussed above (e.g., for correcting output signals to compensate for off-axis misalignment).

[0063] Figure 8D Depicts an exemplary planar multipole magnet array (similar to Figures 5A-5C ) and a perspective view of an exemplary magnetic field sensor 815d, the planar multipole magnet array also having adjacent straight, non-angled magnetic track portions. Planar multipole magnet array 800d includes an angled magnetic layer portion having three adjacent tilted magnetic tracks 805d. Above the angled magnetic layer portion 805d is a straight magnetic layer portion 810d. Straight magnetic layer portion 810d includes two north-south track portions that run parallel to the length of planar multipole magnet array 800d. In contrast, the angled magnetic layer portion 805d has alternating north-south portions that run at an acute angle relative to the length of planar multipole magnet array 800d.

[0064] Angular magnetic field sensor 815d is positioned above the top surface of tilted magnetic layer portion 805d in the middle of three tilted adjacent tracks, while misaligned magnetic field sensor 820d is positioned adjacent to the top surface of straight magnetic layer portion 810d. These sensors 815d and 820d have similar functions to sensors 815a and 820a discussed above. Specifically, relative movement between planar multipole magnet array 800d and magnetic field sensors 815d and 820d may cause misalignment due to stacking tolerances or aging, and this misalignment can be detected by misaligned magnetic field sensor 820d.

[0065] For example, magnetic field sensors 815d and 820d can be stationary while planar multipole magnet array 800d moves. If the movement of planar multipole magnet array 800d is not parallel to the length of planar multipole magnet array 800d, this misaligned movement can be detected by misaligned magnetic field sensor 820d (due to the varying magnetic field near misaligned magnetic field sensor 820d). However, in a properly aligned state, there may not actually be a change in the magnetic field surrounding misaligned magnetic field sensor 820d because misaligned magnetic field sensor 820d can remain at the same widthwise position along straight magnetic layer portion 810d. Therefore, a varying output of misaligned magnetic field sensor 820d (due to misalignment of planar multipole magnet array 800d) can indicate misalignment, while a constant output of misaligned magnetic field sensor 820d (due to proper alignment of planar multipole magnet array 800d) can indicate proper alignment and be used to correct signal output 815d.

[0066] In some examples, if the cylindrical multipole magnet array is attached to a damaged or worn rotating shaft, the rotating shaft may rotate around an axis that is not aligned with the central axis about which the shaft is configured to rotate. In this case, the cylindrical multipole magnet array may exhibit off-axis misalignment motion (e.g., nutating motion). This off-axis motion may be measured by an off-axis misalignment magnetic field sensor, which may output an electrical signal indicative of the off-axis motion. The measured values ​​of the off-axis misalignment magnetic field sensor may then be used to correct the measured values ​​of the angular magnetic field sensor. By taking into account any off-axis misalignment, the measured values ​​obtained by the off-axis misalignment magnetic field sensor may be combined with the measured values ​​of the angular magnetic field sensor to provide a more accurate measurement of the angular rotation of the cylindrical multipole magnet array.

[0067] In some examples, the tilt angle of a cylindrical radial multi-pole magnet array can be adjusted to produce N cycles for each rotation of the ring magnet to replace resolvers for applications where resolvers are typically used, such as control of N-pole electric motors.

[0068] Figure 9 Depicted is an exemplary radial disk multipole magnet array in which three adjacent magnetic north-south tracks have tilted angles (similar to Figure 7 ), adjacent magnetic north-south tracks are oriented in a spiral shape and have different degrees of spiraling. The monopolar radial disk multipole magnet array 900 depicts a spiral pattern corresponding to a "monopolar" design. As shown, the monopolar radial disk multipole magnet array 900 has three adjacent magnetized tracks 900a, 900b, and 900c, which have the same width w and some of which taper into infinitesimal slices as one moves clockwise (or counterclockwise) around the monopolar radial disk multipole magnet array 900. When associated with a magnetic sensing probe, this "monopolar" magnetic design pattern can provide a periodic signal output for every 360° rotation.

[0069] The two-pole radial disk multipole magnet array 905 depicts a spiral pattern corresponding to a "two-pole" design. As shown, the two-pole radial disk multipole magnet array 905 has three adjacent magnetized tracks 900a, 900b, and 900c, which have the same width w and taper into infinitesimal slices as one moves clockwise (or counterclockwise) around the two-pole radial disk multipole magnet array 905. When associated with a magnetic sensing probe, this "two-pole" magnetic design pattern can provide two periodic signal outputs for every 360° rotation.

[0070] The quadrupole radial disk multipole magnet array 910 depicts a spiral pattern corresponding to a "quadrupole" design. As shown, the quadrupole radial disk multipole magnet array 910 has four adjacent magnetized tracks 900a, 900b, 900c, and 900d, which have the same width w and taper into infinitesimal slices as one moves clockwise (or counterclockwise) around the quadrupole cylindrical radial multipole magnet array 910. When associated with a magnetic sensing probe, this "quadrupole" magnetic design pattern can provide three periodic signal outputs for every 360° rotation.

[0071] For each of the radial disk multipole magnet array designs 900, 905, and 910, the tightness of the convolution or tilt angle (which determines the number of "poles") can be tailored to produce an N-cycle sinusoidal signal for each rotation of the radial disk multipole magnet array. More generally, in various embodiments, the pitch angle or tilt angle of a radial disk multipole magnet array having an outer radius R can be specifically adjusted to produce N cycles for each rotation of the radial disk multipole magnet array. The adjusted convolution pitch angle θ is N For generating N periods P of a sinusoidal electrical signal for every 360 degree rotation of a radial disk multipole magnet array having at least three adjacent poles with a constant pole width w. The angle θ at which the N periods P will be generated N It is given by:

[0072]

[0073] A radial disk multipole magnet array can be configured to replace a rotary transformer for controlling an N-pole electric motor. For example, an electric motor having four poles (N=4) can use a four-pole cylindrical radial multipole magnet array to generate four cycles per rotation. In another example, an electric motor having sixteen poles (N=16) can use a sixteen-pole cylindrical radial multipole magnet array to generate sixteen cycles per rotation. In this sense, the number of poles of the cylindrical radial multipole magnet array can be advantageously tailored to a specific type of electric motor having a specific number of poles.

[0074] In some examples, two additional concentric north-south tracks can be located on the inner radius and / or outer radius of the axially (or radially) magnetized ring. An additional magnetic field sensor can be positioned in the middle of the two additional tracks to measure any off-axis misalignment due to aging or stacking tolerances. The measurements of this additional magnetic field sensor can be used to correct the output of the sensor signal accordingly (e.g., to account for off-axis misalignment). In some examples, in an "axial design" (see, e.g., Figure 1 and Figure 8C ) and “graphic design” (see e.g. Figure 8D ), the addition of two non-inclined north-south tracks can also be applied.

[0075] Figure 10 A cross-sectional view of an exemplary power steering system and a block diagram of an exemplary power steering monitoring and control system are depicted. For example, mechanical system 1000 is used to control the steering of wheels in an automobile. Mechanical system 1000 is connected to power steering monitoring and control system 1005.

[0076] Mechanical system 1000 includes a steering column 1010. Steering column 1010 may be operably coupled to, for example, a steering wheel of an automobile (not shown). Fixedly coupled to steering column 1010 is a cylindrical radial multi-pole magnet array 1015 similar in construction to a conventional magnetic field. Figure 8A 800a (e.g., including a spiral magnetic layer portion 1015a (corresponding to 805a) and a concentric north and south pole layer portion 1015b (corresponding to 810a)). In some examples, when a user turns the steering wheel of a car, the rotation can impart a rotational motion on the steering column 1010, which also causes the cylindrical radial multipole magnet array 1015 to rotate.

[0077] Mechanical system 1000 also includes a steering shaft 1020. Steering column 1010 and steering shaft 1020 are operably coupled to each other via a torsion bar 1025. Steering shaft 1020 has a pinion 1030 at its distal end. Pinion 1030 is configured to drive a rack 1035 connected to a wheel (not shown) of the vehicle. Steering shaft 1020 includes a worm gear 1040. Worm gear 1040 is driven by a motor 1045 having a worm 1048.

[0078] The rotation of the cylindrical radial multipole magnet array 1015 is measured by angular magnetic field sensor 1050a by detecting the changing magnetic field caused by the rotation of the spiral magnetic layer portion 1015a. The off-axis misalignment magnetic field sensor 1050b measures the magnetic field generated by the concentric north and south pole layer portions 1015b. For example, if there is no axial misalignment of the cylindrical radial multipole magnet array 1015, the output signal of the off-axis misalignment magnetic field sensor 1050b will not change (e.g., it will be constant) as the cylindrical radial multipole magnet array 1015 rotates. However, if there is axial misalignment of the cylindrical radial multipole magnet array 1015, the output signal of the off-axis misalignment magnetic field sensor 1050b will change as the cylindrical radial multipole magnet array 1015 rotates. This changing output signal is used to correct any artifacts in the output signal of the angular magnetic field sensor 1050a caused by the axial misalignment.

[0079] With respect to power steering monitoring and control system 1005, the output signals from magnetic field sensors 1050a and 1050b are respectively transmitted to a first signal processing module 1055a and a second signal processing module 1055b. Signal processing modules 1055a and 1055b perform various signal processing functions on the corresponding output signals from magnetic field sensors 1050a and 1050b. For example, signal processing modules 1055a and 155b can perform random filtering, sampling, digital signal processing, statistical operations, spectrum analysis, time-frequency / sequence analysis, threshold processing, digital-to-analog (D / A) conversion, analog-to-digital conversion (D / A) conversion and / or data conversion. In some embodiments, signal processing modules 1055a and 155b can convert the analog signals received from their corresponding magnetic field sensors 1050a and 1050b into digital signals.

[0080] The output signals from magnetic field sensors 1050a and 1050b are forwarded to microcontroller 1060 after being processed by signal processing modules 1055a and 1055b, respectively. Microcontroller 1060 is coupled to random access memory (RAM) 1065. Microcontroller 1060 is also coupled to non-volatile memory (NVM) 1070, which contains program instructions that, when executed by microcontroller 1060, cause the microcontroller to perform various program functions. For example, NVM 1070 may include program instructions for an off-axis compensation algorithm 1070a. Off-axis compensation algorithm 1070a may take as input the processed signals from signal processing modules 1055a and 1055b and correct for any off-axis misalignment of cylindrical radial multi-pole magnet array 1015. For example, the off-axis compensation algorithm 1070a can cause the microcontroller 1060 to subtract the output signal of the off-axis misalignment magnetic field sensor 1050b from the output signal of the angular magnetic field sensor 1050a to generate a corrected rotation signal (i.e., to account for any axial misalignment). The microcontroller 1060 can then use the corrected rotation signal to control the motor 1045.

[0081] Coupled to the microcontroller 1060 is a third signal processing module 1075 that performs various signal processing functions similar to the signal processing modules 1055a and 155b. The motor 1045 is coupled to the third signal processing module 1075 so that the motor 1045 receives commands from the microcontroller 1060.

[0082] In the exemplary embodiment, the corrected rotation signal calculated by the microcontroller 1060 can be forwarded to the third signal processing module 1075, which can convert the corrected rotation signal from a digital signal to an analog signal. This analog signal can then be provided to the motor 1045 to control various operating parameters of the motor 1045. For example, a sinusoidal input signal from the angular magnetic field sensor 1050a (as a result of the user continuously turning the steering wheel clockwise and counterclockwise) can be converted into a sinusoidal control output signal to the motor 1045. This sinusoidal control output signal can cause the worm 1048 to rotate clockwise and counterclockwise in a sinusoidal manner, thereby translating into the wheel connected to the rack 1035 oscillating between turning right and turning left. In this sense, the vehicle's power steering system operates using the mechanical system 1000 and the power steering monitoring and control system 1005.

[0083] While various embodiments have been described with reference to the accompanying drawings, other embodiments are possible. For example, the cylindrical magnet array can have the shape of a hollow cylinder. The hollow cylinder design can allow the cylindrical magnet array to be attached to a shaft. In some embodiments, the cylindrical magnet array can have the shape of a closed cylinder. The closed cylinder design can advantageously allow for more magnetic layers in the cylindrical magnet array.

[0084] In various embodiments, the magnetic field sensor / magnetic field probe may not be limited to a specific type of magnetic field sensor. For example, the magnetic field sensor may be any of the following types of magnetic field sensors: a Hall effect sensor, a magneto-diode, a magneto-transistor, an anisotropic magnetoresistive (AMR) magnetometer, a giant magnetoresistive (GMR) magnetometer, a magnetic tunnel junction magnetometer, a magneto-optical sensor, a micro-electromechanical system (MEMS) sensor based on Lorentz force, a MEMS sensor based on electron tunneling, a MEMS compass, a nuclear precession magnetic field sensor, an optically pumped magnetic field sensor, a fluxgate magnetometer, a search coil magnetic field sensor, a magnetoresistive sensor, a tunnel magnetoresistive (TMR) sensor, or a superconducting quantum interference (SQUID) magnetometer. In some examples, where more than one magnetic field sensor is deployed, they may be of different types. For example, if two magnetic field sensors are used to detect movement of a magnetic array, one sensor may be an AMR magnetometer and the other may be a Hall effect sensor.

[0085] In some examples, the magnetic field sensor may include two interleaved or overlapping magnetoresistive (MR) Wheatstone bridge sensors. The two MR bridge sensors may be offset 45 degrees relative to each other. Measuring the differential signal of the two MR bridge sensors (via a comparator or operational amplifier) ​​may advantageously generate separate sine and cosine signals (e.g., signals that are phase-shifted by 90 degrees). The periodic sine and cosine signal outputs generated by the two MR bridges tilted 45 degrees relative to each other may be the result of the relative movement of the MR bridges over a multi-pole magnetic array (e.g., a linear track or a multi-pole ring magnet). These sine and cosine signals may allow for the extraction of the angle, velocity, direction, and linear position of the multi-pole magnetic array (e.g., using an inverse tangent function to extract position information). In some examples, the displacement of the magnetic field sensor in the x-direction over the multi-pole magnetic array may generate a periodic sinusoidal signal output per magnetic pole length P (one period). The air gap between the multi-pole magnet array and the magnetic field sensor may be between P / 2 and P / 4 to minimize distortion of the sinusoidal signal. For example, two MR bridges may have periodic outputs defined by Y1 = cos(2πX / P) and Y2 = sin(2πX / P), respectively.

[0086] In some embodiments, the linear displacement of the magnetic field sensor relative to a multi-pole magnet array tilted at an angle θ can generate a sinusoidal signal with a period P, which can depend on the value of θ. Thus, two MR bridges can generate sine and cosine signals using a periodic multi-pole magnet array with a pole width of w, where the signal period is:

[0087]

[0088] By introducing an angle θ between the displacement of the magnetic field sensor and the direction of the adjacent magnetic pole. This can be done while maintaining the air gap between the magnetic field sensor and the multipolar magnetic track between w / 2 and w / 4 to minimize sinusoidal signal distortion. In various embodiments, the magnetic field sensor can be stationary while the multipolar magnet array can be in motion. Alternatively, the magnetic field sensor can be in motion while the multipolar magnet array can be stationary.

[0089] In various examples, the magnetic field sensor may be an anisotropic magnetoresistive (MR) sensor. Such a sensor may be sensitive to magnetic fields that are parallel to the plane in which the magnetic field sensor is located. Such a sensor can detect the angle of the magnetic field but cannot distinguish the polarity of the magnetic field.

[0090] Figure 1 、 Figure 2 、 Figures 4A-4C , Figure 6A and Figure 8C The illustrated embodiment may be referred to as an "axial design," "cylindrical design," or "helical design" for a multi-pole magnet array. Figure 6B 、 Figure 7 、 Figures 8A-8B 、 Figure 9 and Figure 10 The illustrated embodiment may be referred to as a “radial design,” “disc design,” or “disc design” for a multi-pole magnet array. For example, both the axial and radial designs may be advantageously mounted to a rotating shaft of a motor. Figure 3 、 Figures 5A-5C and Figure 8D The embodiment shown may be referred to as a "planar design" for a multi-pole magnet array. The planar design may advantageously be integrated into a flat track located on an assembly line for use in monitoring the speed at which the assembly line moves.

[0091] Some embodiments may include a device suitable for detecting the position of a rotating shaft as an alternative to a rotary transformer. In some embodiments, a cylindrical magnet may have a rotationally symmetric central axis and individually magnetized layers, each of the individually magnetized layers being adjacent to at least one oppositely magnetized layer. The individually magnetized layers may be wound around the rotationally symmetric central axis such that each of the individually magnetized layers is monotonically arranged relative to the rotationally symmetric central axis according to a radial angle α about the rotationally symmetric central axis.

[0092] In various examples, the at least one magnetic field sensor can be configured to detect a changing magnetic field in response to relative motion between a cylindrical magnet and the at least one magnetic field sensor. The at least one magnetic field sensor can be configured to output a motion signal indicative of the relative motion between the cylindrical magnet and the at least one magnetic field sensor. The at least one magnetic field sensor can include two MR bridges rotated 45 degrees relative to each other and disposed proximate to the cylindrical magnet, such that when the cylindrical magnet rotates at a constant angular velocity relative to the magnetic field sensor, one of the two MR bridges generates a sine signal and the other of the two MR bridges generates a cosine signal.

[0093] In some examples, when the cylindrical magnet rotates about the rotationally symmetric central axis, the movement of successive individually magnetized layers can be by a translation angle θ greater than zero and less than 90 degrees relative to the at least one magnetic field sensor. Each of the individually magnetized layers can have a width p, such that the sine and cosine signals can have a period of P = p / cos(θ) per rotation of the cylindrical magnet.

[0094] In some embodiments, the at least one magnetic field sensor can be radially disposed from the center and the rotational axis of the magnet such that the at least one magnetic field sensor is disposed proximate to the outer periphery of the cylindrical magnet. In various examples, the at least one magnetic field sensor can be radially and axially disposed from the center and the rotational axis of the cylindrical magnet such that the at least one magnetic field sensor is disposed proximate to the top surface of the cylindrical magnet.

[0095] In some examples, the individual magnetized layers can be oriented in a radial spiral relative to the rotational center axis, such that each of the individual magnetized layers is disposed at increasing radial distances from the rotational center axis according to increasing radial angle α about the rotational center axis. The top surface of the disk magnet can have magnetic field lines that are substantially concentric with the rotational center axis. Some examples can include concentric north-south disk magnets integrated with the disk magnet.

[0096] In various embodiments, the individually magnetized layers may be oriented in a helix having a helical axis aligned with a central axis of rotational symmetry, such that each of the individually magnetized layers is progressively wound around the helical axis as an axial displacement d along the helical axis. z The outer surface of the disk magnet may have magnetic field lines that are substantially orthogonal to the central axis of rotational symmetry.

[0097] A position measurement system for measuring the position of a movable device relative to a fixed device may include a two-dimensional (2D) surface magnet array, wherein adjacent magnetized tracks have sequentially alternating magnetic polarities, and each magnetized track has a constant width w. The position measurement system for measuring the position of a movable device relative to a fixed device may include at least one magnetic field sensor positioned proximate to the 2D surface magnet array and maintaining a constant air gap relative to the magnet array. In some examples, the 2D surface magnet array and the at least one magnetic field sensor may be in a specific relative orientation such that the relative track of the at least one magnetic field sensor is configured to be tilted at an acute angle θ relative to the length direction of at least three adjacent magnetized tracks of the 2D surface magnet array. In response to relative movement along the relative track, the at least one magnetic field sensor may be configured to generate a periodic position signal having a period P of the periodic position signal. θ The magnetic field sensor may be configured to sense the magnetic field generated by at least two (or at least three) adjacent magnetized tracks. In various examples, the 2D surface magnet array may have two or more magnetized bands, resulting in three or more magnetized tracks.

[0098] In some embodiments, in response to the relative movement along the relative trajectory, at least one magnetic field sensor can be configured to generate a periodic position signal having a period P of θ It depends at least in part on the width w and the acute angle of inclination θ according to the following equation:

[0099] Where a=1 or a=2,

[0100] Where a=1 covers the case where the magnetic field sensor (e.g., a magnetic probe) outputs one cycle per magnetic pole (e.g., a single north or south pole), and a=2 covers the case where the magnetic field sensor outputs one cycle per magnetic pole pair (e.g., a pair of magnetic poles including a north pole and a south pole). Depending on the type of magnetic field sensor used, the magnetic field sensor may output one cycle for each north pole or south pole, or one cycle for each north pole / south pole pair. For example, a magnetoresistive magnetic probe may output one cycle for each north pole or south pole (meaning one cycle for crossing the north pole, followed by another cycle for crossing the south pole). In some examples, a Hall effect magnetic probe may output one cycle for each magnetic pole pair (meaning one cycle for crossing a combined south / north pole pair). Different periodic outputs may be the result of specific characteristics of a given magnetic field sensor. For example, a TMR or Hall effect sensor may be able to distinguish between a north pole and a south pole and may produce a single cycle when it crosses a south / north pole pair, while an AMR sensor may provide two cycles when it crosses a south / north pole pair (e.g., one cycle for crossing the north pole, followed by another cycle for crossing the south pole).

[0101] Some aspects of the embodiments can be implemented as a computer system. For example, various embodiments can include digital circuits and / or analog circuits, computer hardware, firmware, software, or a combination thereof. The device elements can be implemented in a computer program product tangibly embodied in an information carrier (e.g., a machine-readable storage device) for execution by a programmable processor; and the method can be performed in the following manner: the programmable processor executes an instruction program to perform the functions of the various embodiments by operating on input data and generating output. Some embodiments can be advantageously implemented in one or more computer programs executable on a programmable system, the programmable system including at least one programmable processor coupled to receive data and instructions from a data storage system, at least one input device, and / or at least one output device, and transmit data and instructions to the data storage system, at least one input device, and / or at least one output device. A computer program is a set of instructions that can be used directly or indirectly in a computer to perform an activity or produce a result. A computer program can be written in any form of programming language, including compiled or interpreted languages, and the computer program can be deployed in any form, including as a standalone program or as a module, component, subroutine, or other unit suitable for use in a computing environment.

[0102] Suitable processors for executing a program of instructions include, by way of example and not limitation, both general-purpose and special-purpose microprocessors, which may comprise a single processor or one of multiple processors of any type of computer. Generally speaking, a processor will receive instructions and data from a read-only memory or a random access memory, or both. The essential elements of a computer are a processor for executing instructions and one or more memories for storing instructions and data. Storage devices suitable for tangibly embodying computer program instructions and data include all forms of non-volatile memory, including (by way of example) semiconductor memory devices such as EPROM, EEPROM, and flash memory devices; magnetic disks such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. The processor and memory may be supplemented by or incorporated into an ASIC (application-specific integrated circuit). In some embodiments, the processor and components may be supplemented by or incorporated into a hardware programmable device, such as an FPGA, for example.

[0103] In some embodiments, each system can be programmed with the same or similar information and / or initialized with substantially the same information stored in volatile memory and / or non-volatile memory. For example, a data interface can be configured to perform auto-configuration, auto-download, and / or auto-update functions when coupled to an appropriate host device (such as a desktop computer or server).

[0104] In some embodiments, one or more user interface features may be custom configured to perform a specific function. Exemplary embodiments may be implemented on a computer system that includes a graphical user interface and / or an internet browser. To provide for interaction with a user, some embodiments may be implemented on a computer having a display device (such as an LCD (liquid crystal display) monitor for displaying information to the user), a keyboard, and a pointing device (such as a mouse or trackball) through which the user can provide input to the computer.

[0105] In various embodiments, the system can communicate using suitable communication methods, devices, and techniques. For example, the system can communicate with compatible devices (e.g., devices capable of transmitting data to and / or from the system) using point-to-point communication, where messages are transmitted directly from the source to the receiver via a dedicated physical link (e.g., a fiber optic link, an infrared link, an ultrasonic link, point-to-point wiring, a daisy chain). Components of the system can exchange information via any form or medium of analog or digital data communication, including packet-based messaging over a communication network. Examples of communication networks include, for example, LANs (local area networks), WANs (wide area networks), MANs (metropolitan area networks), wireless and / or optical networks, as well as the computers and networks that form the Internet. Other embodiments can deliver messages via broadcast to all or substantially all devices coupled together via the communication network, for example, using omnidirectional radio frequency (RF) signals. Other embodiments can deliver messages characterized by high directionality, such as RF signals transmitted using directional (i.e., narrow beam) antennas or infrared signals that can optionally be used with focusing optics. Other embodiments may also be implemented using appropriate interfaces and protocols such as, by way of example and not limitation, USB 2.0, FireWire, ATA / IDE, RS-232, RS-422, RS-485, 802.11a / b / g / n, Wi-Fi, WiFi-Direct, Li-Fi, Bluetooth, Ethernet, IrDA, FDDI (Fiber Distributed Data Interface), Token Ring networks, or frequency, time, or code division based multiplexing techniques. Some embodiments may optionally include features such as error checking and correction (ECC) for data integrity, or security measures such as encryption (e.g., WEP) and password protection.

[0106] In various embodiments, a computer system may include non-transitory memory. The memory may be connected to one or more processors, which may be configured to encode data and computer-readable instructions, including processor-executable program instructions. The data and computer-readable instructions may be accessible to the one or more processors. The processor-executable program instructions, when executed by the one or more processors, may cause the one or more processors to perform various operations.

[0107] In various embodiments, a computer system may include an Internet of Things (IoT) device. An IoT device may include objects embedded with electronics, software, sensors, actuators, and network connectivity that enable these objects to collect and exchange data. An IoT device can be used with wired or wireless devices by sending data to another device through an interface. An IoT device can collect useful data and then autonomously flow the data between other devices.

[0108] A number of embodiments have been described. However, it should be understood that various modifications are possible. For example, advantageous results may be achieved if the steps of the disclosed techniques are performed in a different order, or if the components of the disclosed systems are combined in a different manner, or if components are supplemented with other components. Therefore, other implementations are within the scope of the following claims.

Claims

1. A method for measuring a position of a movable device relative to a fixed device, the method comprising: positioning at least one magnetic field sensor proximate to a two-dimensional surface magnet array and maintaining a constant air gap relative to the two-dimensional surface magnet array; The two-dimensional surface magnet array has at least three adjacent magnetized tracks, the at least three adjacent magnetized tracks have sequentially alternating magnetic polarities, and each magnetized track has a constant width w; configuring the relative trajectory of the at least one magnetic field sensor to be inclined at an acute angle θ relative to the length direction of the at least three adjacent magnetized tracks of the two-dimensional surface magnet array, wherein the relative trajectory comprises a rotation of the two-dimensional surface magnet array relative to the at least one magnetic field sensor, Wherein, the two-dimensional surface magnet array comprises one of the following: an axial cylindrical spiral multipole magnet array with an outer radius R or a radial disc-shaped spiral multipole magnet array with an outer radius R, Wherein, in response to the relative movement along the relative trajectory, the at least one magnetic field sensor is configured to generate a periodic position signal having a period P θ , the period P θ It depends at least in part on the width w and the acute inclination angle θ according to the following formula: Where a=1 or a=2, The acute tilt angle θ is set so that the at least one magnetic field sensor is configured to generate N cycles of the periodic position signal for every 360° rotation of the axial cylindrical spiral multi-pole magnet array based on the following formula: Among them, θ N is the angle that generates N cycles.

2. The method according to claim 1, further comprising: The two-dimensional surface magnet array is coupled to one of an inner race and an outer race of a bearing, and the at least one magnetic field sensor is coupled to the other of the inner race and the outer race.

3. The method according to claim 1: in, The two-dimensional surface magnet array further comprises: a circularly stacked north-south magnetized track having a common central axis with the axial cylindrical spiral multipole magnet array, and wherein the at least one magnetic field sensor comprises: a position magnetic field sensor disposed above a side surface of the axial cylindrical spiral multipole magnet array; and An axially misaligned magnetic field sensor is disposed above a side surface of the circularly stacked north-south magnetized tracks.

4. The method according to claim 1, wherein The acute tilt angle θ is set such that the at least one magnetic field sensor is configured to generate N cycles of the periodic position signal for every 360° rotation of the radial disk-shaped spiral multi-pole magnet array based on the following formula: Among them, θ N is the angle that generates N cycles.

5. The method according to claim 1: in, The two-dimensional surface magnet array further comprises: a circular concentric north-south magnetized track having a common central axis with the radial disc-shaped spiral multipole magnet array, and Wherein, the at least one magnetic field sensor comprises: a position magnetic field sensor disposed above a top surface of the radially disc-shaped spiral multi-pole magnet array; and A radially misaligned magnetic field sensor is disposed above a top surface of the circular concentric north-south magnetized track.

6. The method according to claim 1, wherein The relative trajectory includes translation of the two-dimensional surface magnet array relative to the at least one magnetic field sensor.

7. The method according to claim 6, wherein: The two-dimensional surface magnet array includes a planar multi-pole magnet array having a length L.

8. The method according to claim 7, wherein: The acute tilt angle θ is set such that the at least one magnetic field sensor is configured to generate N periods of the periodic position signal for each displacement over the length L of the two-dimensional surface magnet array based on the following formula: Among them, θ N is the angle that generates N cycles.

9. The method according to claim 8: in, The two-dimensional surface magnet array further comprises: a straight stacked north-south magnetized track running parallel to the length L of the two-dimensional surface magnet array and disposed above the planar multipole magnet array, and, Wherein, the at least one magnetic field sensor comprises: an angular magnetic field sensor disposed above a top surface of the planar multi-pole magnet array; and An off-axis misaligned magnetic field sensor is disposed above a top surface of the straight stacked north-south magnetized tracks.

10. A position measurement system for measuring a position of a movable device relative to a fixed device, the position measurement system comprising: A two-dimensional surface magnet array wherein at least three adjacent magnetized tracks have sequentially alternating magnetic polarities, each magnetized track having a constant width w; and at least one magnetic field sensor disposed proximate to the two-dimensional surface magnet array and maintaining a constant air gap therewith, wherein the air gap distance between the at least one magnetic field sensor and the two-dimensional surface magnet array is between w / 2 and w / 4 to minimize signal distortion, wherein the two-dimensional surface magnet array and the at least one magnetic field sensor are in a specific relative orientation such that the relative track of the at least one magnetic field sensor is configured to be tilted at an acute angle θ relative to the length direction of the at least three adjacent magnetized tracks of the two-dimensional surface magnet array, In response to the relative movement along the relative trajectory, the at least one magnetic field sensor is configured to generate a periodic position signal having a period P θ , the period P θ It depends at least in part on the width w and the acute inclination angle θ according to the following formula: Wherein a=1 or a=2. 11 . The position measurement system of claim 10 , wherein the relative trajectory comprises a rotation of the two-dimensional surface magnet array relative to the at least one magnetic field sensor. 12 . The position measurement system of claim 11 , wherein the two-dimensional surface magnet array comprises an axial cylindrical spiral multipole magnet array having an outer radius R. 13 . The position measurement system of claim 11 , wherein the two-dimensional surface magnet array is a radial disk-shaped spiral multipole magnet array having an outer radius R.

14. The position measurement system of claim 12 , wherein the acute tilt angle θ is set such that the at least one magnetic field sensor is configured to generate N cycles of the periodic position signal for every 360° rotation of the axial cylindrical spiral multi-pole magnet array based on the following formula: in, θ N is the angle that generates N cycles.

15. The position measurement system of claim 12 , further comprising a bearing having an inner race and an outer race, wherein the two-dimensional surface magnet array is fixedly coupled to one of the inner race and the outer race, and the at least one magnetic field sensor is fixedly coupled to the other of the inner race and the outer race.

16. The position measurement system according to claim 12: Wherein the two-dimensional surface magnet array further comprises: a circularly stacked north-south magnetized track having a common central axis with the axial cylindrical spiral multipole magnet array, and wherein the at least one magnetic field sensor comprises: a position magnetic field sensor disposed above a side surface of the axial cylindrical spiral multipole magnet array; and An axially misaligned magnetic field sensor is disposed above a side surface of the circularly stacked north-south magnetized tracks.

17. The position measurement system of claim 13 , wherein the acute tilt angle θ is set such that the at least one magnetic field sensor is configured to generate N cycles of the periodic position signal for every 360° rotation of the radial disk-shaped spiral multi-pole magnet array based on the following formula: in, θ N is the angle that generates N cycles.

18. The position measurement system of claim 13 , further comprising a bearing having an inner race and an outer race, wherein the two-dimensional surface magnet array is fixedly coupled to one of the inner race and the outer race, and the at least one magnetic field sensor is fixedly coupled to the other of the inner race and the outer race.

19. The position measurement system according to claim 13: Wherein the two-dimensional surface magnet array further comprises: a circular concentric north-south magnetized track having a common central axis with the radial disc-shaped spiral multipole magnet array, and wherein the at least one magnetic field sensor comprises: a position magnetic field sensor disposed above a top surface of the radially disc-shaped spiral multi-pole magnet array; and A radially misaligned magnetic field sensor is disposed above a top surface of the circular concentric north-south magnetized track.

20. The position measurement system of claim 10, wherein the relative trajectory comprises translation of the two-dimensional surface magnet array relative to the at least one magnetic field sensor.

21. The position measurement system of claim 20, wherein the two-dimensional surface magnet array comprises a planar multi-pole magnet array having a length L.

22. The position measurement system of claim 21 , wherein the acute tilt angle θ is set such that the at least one magnetic field sensor is configured to generate N cycles of the periodic position signal for each displacement over the length L of the two-dimensional surface magnet array based on the following formula: in, θ N is the angle that generates N cycles.

23. The position measurement system according to claim 21: Wherein the two-dimensional surface magnet array further comprises: a straight stacked north-south magnetized track running parallel to the length L of the two-dimensional surface magnet array and disposed above the planar multipole magnet array, and, wherein the at least one magnetic field sensor comprises: an angular magnetic field sensor disposed above a top surface of the planar multi-pole magnet array; and An off-axis misaligned magnetic field sensor is disposed above a top surface of the straight stacked north-south magnetized tracks. 24 . The position measurement system of claim 10 , wherein the at least one magnetic field sensor is configured to output at least one periodic sinusoidal signal in response to relative movement along the relative trajectory.

25. The position measurement system according to claim 10 further includes the movable device and the fixed device, the movable device having a predetermined trajectory relative to the fixed device, and a constant air gap between the fixed device and the movable device, wherein the at least one magnetic field sensor is fixedly coupled to one of the fixed device and the movable device, and the two-dimensional surface magnet array is fixedly coupled to the other of the fixed device and the movable device.

26. A position measurement system for measuring a position of a movable device relative to a fixed device, the position measurement system comprising: A two-dimensional surface magnet array wherein at least three adjacent magnetized tracks have sequentially alternating magnetic polarities, each magnetized track having a constant width w; and at least one magnetic field sensor disposed proximate to the two-dimensional surface magnet array and maintaining a constant air gap therewith, wherein the two-dimensional surface magnet array and the at least one magnetic field sensor are in a specific relative orientation such that the relative track of the at least one magnetic field sensor is configured to be tilted at an acute angle θ relative to the length direction of the at least three adjacent magnetized tracks of the two-dimensional surface magnet array, wherein the at least one magnetic field sensor is configured to output at least one periodic sine signal and at least one periodic cosine signal in response to relative movement along the relative trajectory, such that the at least one magnetic field sensor allows for absolute position measurement of the two-dimensional surface magnet array relative to the at least one magnetic field sensor within a period of the sine and cosine signals, In response to the relative movement along the relative trajectory, the at least one magnetic field sensor is configured to generate a periodic position signal having a period P θ , the period P θ It depends at least in part on the width w and the acute inclination angle θ according to the following formula: Wherein a=1 or a=2.

27. A position measurement system for measuring a position of a movable device relative to a fixed device, the position measurement system comprising: A two-dimensional surface magnet array wherein at least three adjacent magnetized tracks have sequentially alternating magnetic polarities, each magnetized track having a constant width w; and at least one magnetic field sensor disposed proximate to the two-dimensional surface magnet array and maintaining a constant air gap therewith, wherein the at least one magnetic field sensor comprises two magnetoresistive Wheatstone bridge sensors tilted 45° relative to each other and positioned apart from each other or staggered relative to each other, wherein the two-dimensional surface magnet array and the at least one magnetic field sensor are in a specific relative orientation such that the relative track of the at least one magnetic field sensor is configured to be tilted at an acute angle θ relative to the length direction of the at least three adjacent magnetized tracks of the two-dimensional surface magnet array, wherein in response to movement along the relative trajectory, a first magnetoresistive Wheatstone bridge sensor of the two magnetoresistive Wheatstone bridge sensors is configured to output a sine signal and a second magnetoresistive Wheatstone bridge sensor of the two magnetoresistive Wheatstone bridge sensors is configured to output a cosine signal, such that the two magnetoresistive Wheatstone bridge sensors allow for absolute position measurement of the two-dimensional surface magnet array relative to the at least one magnetic field sensor within a period of the sine and cosine signals, In response to the relative movement along the relative trajectory, the at least one magnetic field sensor is configured to generate a periodic position signal having a period P θ , the period P θ It depends at least in part on the width w and the acute inclination angle θ according to the following formula: Wherein a=1 or a=2.

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