Multi-turn magnetic sensing with mid-range reset and / or flip count

Abstract

The invention relates to multi-turn magnetic sensing with mid-range reset and / or flip counting. Aspects of the present disclosure relate to multi-turn magnetic sensing systems and related methods. A system may include a first multi-turn magnetic sensor and a second multi-turn magnetic sensor, wherein domain walls propagate in opposite directions in the second multi-turn magnetic sensor relative to the first multi-turn magnetic sensor in response to a magnetic field. The decoder may output a number of turns based on states of the first and second multi-turn sensors. The first and second multi-turn sensors may have a reset state corresponding to a number of turns having a value between a minimum value and a maximum value of a count range relative to the reset state.

Description

Technical Field

[0001] The disclosed technology relates to multi-turn magnetic sensors and related systems and methods. Background Art

[0002] A magnetic sensing system may include a multi-turn magnetic sensor that counts the cumulative number of turns of a magnetic field. The multi-turn magnetic sensor may include magnetoresistive elements arranged in series with each other as spiral strips. The resistance of one or more magnetoresistive elements may change in response to the rotation of the magnetic field. The state of the multi-turn magnetic sensing may be decoded from the output signal of the multi-turn magnetic sensor. Summary of the invention

[0003] The innovations described in the claims have several aspects, no single one of which is solely responsible for its desirable attributes. Without limiting the scope of the claims, some of the prominent features of the disclosure will now be described briefly.

[0004] One aspect of the present invention is a multi-turn magnetic sensing system, comprising a first multi-turn magnetic sensor; a second multi-turn magnetic sensor; and a decoder configured to output a number of turns based on output signals from the first multi-turn magnetic sensor and the second multi-turn magnetic sensor. In the multi-turn magnetic sensing system, a domain wall propagates in the second multi-turn magnetic sensor in an opposite direction relative to the first multi-turn magnetic sensor in response to a magnetic field.

[0005] The decoder may determine the number of turns of the first and second multi-turn magnetic sensors relative to a reset state within a range from a first value to a second value, wherein the number of turns of the reset state is between the first value and the second value. The first multi-turn magnetic sensor and the second multi-turn magnetic sensor may both count the same number of turns in opposite directions, and the number of turns of the reset state may be a midpoint between the first value and the second value. The first multi-turn magnetic sensor and the second multi-turn magnetic sensor may both be filled with domain walls in the reset state.

[0006] The decoder may determine from the reset state the number of more than one full clockwise rotation of the magnetic field and determine from the reset state the number of more than one full counterclockwise rotation of the magnetic field.

[0007] The multi-turn magnetic sensing system may include a magnetic reset configured to magnetically reset the first and second multi-turn magnetic sensors to the reset state. The decoder may determine the number of turns within a range from the first value to the second value relative to the reset state. The number of turns of the reset state may have a value between the first value and the second value. In some embodiments, the magnetic reset may include a coil configured to apply a reset magnetic field to reset the first and second multi-turn magnetic sensors to the reset state. The multi-turn magnetic sensing system may include a memory storing an index value. The multi-turn magnetic sensing system may update the index value in association with magnetically resetting the first and second multi-turn magnetic sensors. The decoder may generate the number of turns based on the index value and output signals from the first multi-turn magnetic sensor and the second multi-turn magnetic sensor.

[0008] When operating in an equilibrium state, the multi-turn magnetic sensing system may operate in a subset of active states of the first and second multi-turn magnetic sensors.

[0009] The first and second multi-turn magnetic sensors may have a state having the same number of turns as that corresponding to the reset state, and the first and second multi-turn magnetic sensors may not be configured to move from the state to the reset state by rotation of a magnetic field.

[0010] The number of turns may have the same value for at least two different states of the first and second multi-turn magnetic sensors.

[0011] A multi-turn magnetic sensing system may include an angle sensor and a processing circuit configured to output a position measurement. The position measurement may be based on the number of turns and an angle, wherein the angle is based on an output signal of the angle sensor.

[0012] Another aspect of the present invention is a multi-turn magnetic sensing system with a mid-range reset function. The multi-turn magnetic sensing system includes: a first multi-turn magnetic sensor; a second multi-turn magnetic sensor; and a decoder configured to output a number of turns associated with the state of the first multi-turn magnetic sensor and the second multi-turn magnetic sensor. Domain walls propagate in opposite directions in the second multi-turn magnetic sensor and the first multi-turn magnetic sensor in response to a magnetic field. The number of turns ranges from a minimum value to a maximum value relative to a reset state. The number of turns in the reset state is between the minimum value and the maximum value.

[0013] The multi-turn magnetic sensing system may include a magnetic resetter configured to magnetically reset the first and second multi-turn magnetic sensors to the reset state.

[0014] Another aspect of the present invention is a multi-turn magnetic sensing method with mid-range reset. The method includes resetting a first multi-turn sensor and a second multi-turn sensor to a reset state, wherein domain walls propagate in opposite directions in the first multi-turn sensor and the second multi-turn sensor in response to a rotation of a magnetic field; detecting a first non-zero number of turns of the magnetic field from the reset state based on a first value read from the first multi-turn sensor and the second multi-turn sensor, the first non-zero number of turns indicating an accumulated rotation of the magnetic field from the reset state in a clockwise direction; and detecting a second non-zero number of turns of the magnetic field relative to the reset state based on a second value read from the first multi-turn sensor and the second multi-turn sensor, the second non-zero number of turns indicating an accumulated rotation of the magnetic field from the reset state in a counterclockwise direction.

[0015] The method may include generating a position measurement based on the number of turns and the angle information.

[0016] The first multi-turn sensor and the second multi-turn sensor may each include a magnetic spiral having the same number of turns.

[0017] In the reset state, the first multi-turn sensor and the second multi-turn sensor may both be filled with domain walls.

[0018] The method may include: magnetically resetting the first multi-turn sensor in response to a magnetic field rotating a certain number of turns; updating an index value stored in a memory associated with the magnetic reset; and after the update and additional rotation of the magnetic field, determining the number of turns based on the index value and reading a third value from the first multi-turn sensor and the second multi-turn sensor.

[0019] The method may include generating a position measurement based on the number of turns and angle information associated with the magnetic field.

[0020] Another aspect of the present invention is a multi-turn magnetic sensing method with flip count. The method includes resetting a multi-turn magnetic sensor to a reset state, wherein the multi-turn magnetic sensor includes a magnetic spiral having N turns, and wherein N is a positive integer greater than 1; updating an index value associated with the reset; and determining a number of turns based on an output signal from the multi-turn magnetic sensor and the index value, wherein the number of turns has a value with a magnitude greater than N.

[0021] The resetting may include applying a resetting magnetic field to the multi-turn magnetic sensor using a coil. The resetting may include moving a permanent magnet near the multi-turn magnetic sensor.

[0022] The determining of the number of turns may also be based on an output signal from a second multi-turn magnetic sensor, wherein domain walls propagate in an opposite direction in the second multi-turn magnetic sensor compared to the multi-turn magnetic sensor. The method further includes generating the number of turns having a second value after additionally rotating the magnetic field after the determining, wherein the value represents a clockwise rotation from an initialized state, and wherein the second value represents a counterclockwise rotation from the initialized state. The multi-turn magnetic sensor and the second multi-turn magnetic sensor may both be populated with domain walls in a reset state.

[0023] The number of turns may have a quarter-turn resolution.

[0024] The method may entail: processing an output signal from an angle sensor to generate angle information; and generating a position measurement value based on the number of turns and the angle information.

[0025] Another aspect of the present invention is a multi-turn magnetic sensing system with flip count. The multi-turn magnetic sensing system includes a multi-turn magnetic sensor and a processing circuit. The multi-turn magnetic sensor includes a magnetic spiral of N turns, where N is a positive integer greater than 1. The processing circuit includes: a memory configured to store an index value; and a decoder configured to determine the number of turns having a value greater than N in magnitude based on an output signal from the multi-turn magnetic sensor and the index value. The number of turns represents the number of rotations of the magnetic field.

[0026] The multi-turn magnetic sensing system may include a magnetic resetter configured to magnetically reset the magnetic spiral. The magnetic reset includes a coil configured to apply a reset magnetic field to magnetically reset the magnetic spiral in response to a control signal from the processing circuit. The processing circuit may update the index value in association with magnetically resetting the magnetic spiral. The processing circuit may update the index value in response to detecting a rotation of the magnetic field after magnetically resetting the magnetic spiral.

[0027] The multi-turn magnetic sensing system may include a second multi-turn magnetic sensor, the second multi-turn magnetic sensor including a second magnetic spiral. Domain walls may propagate in opposite directions in the magnetic spiral and the second magnetic spiral. The decoder may determine the number of turns based on an output signal from the multi-turn magnetic sensor, an output signal from the second multi-turn magnetic sensor, and the index value. The second magnetic spiral may have N turns. The processing circuit may detect a change in the rotation direction of the magnetic field. The decoder may determine the number of turns having a second value with a magnitude greater than N, wherein the value represents a clockwise rotation from an initialized state, and wherein the second value represents a counterclockwise rotation from the initialized state.

[0028] The multi-turn magnetic sensing system may include an angle sensor. The processing circuit may output a position measurement based on the number of turns and angle information from the angle sensor.

[0029] Another aspect of the present invention is a multi-turn magnetic sensing system with flip count. The multi-turn magnetic sensing system includes: a first multi-turn magnetic sensor; a second multi-turn magnetic sensor; and a decoder configured to output the number of turns based on the index value and state of the first multi-turn magnetic sensor and the second multi-turn magnetic sensor. The first multi-turn magnetic sensor includes a first magnetic spiral having N turns, where N is a positive integer greater than 1. Domain walls propagate in opposite directions in the second multi-turn magnetic sensor and the first multi-turn magnetic sensor in response to a magnetic field. The decoder is configured to determine the number of turns of the magnetic field exceeding N full clockwise rotations from an initialization state, and determine the number of turns of the magnetic field exceeding N full counterclockwise rotations from the initialization state.

[0030] The multi-turn magnetic sensing system may include a magnetic resetter configured to magnetically reset the first multi-turn magnetic sensor to a reset state. The multi-turn magnetic sensing system may include a processing circuit configured to update the index value in association with the magnetic reset of the first multi-turn magnetic sensor.

[0031] To summarize the present disclosure, certain aspects, advantages, and novel features of the innovations are described herein. It should be understood that not all of these advantages may be achieved according to any particular embodiment. Thus, the innovations may be embodied or implemented in a manner that achieves or optimizes one or a group of advantages taught herein without necessarily achieving other advantages taught or suggested herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Embodiments of the present disclosure will be described by way of non-limiting examples with reference to the accompanying drawings.

[0033] Figure 1A is a schematic diagram of two multi-turn sensors of a multi-turn magnetic sensing system according to an embodiment.

[0034] Figure 1B is the summary of the magnetic field rotation Figure 1A Table of the status and number of turns of a multi-turn magnetic sensing system.

[0035] Figure 2 is a schematic block diagram of a multi-turn magnetic sensing system with mid-position reset according to an embodiment.

[0036] Figure 3 is a schematic block diagram of a multi-turn magnetic sensing system that also includes angle sensing according to an embodiment.

[0037] Figure 4 is a schematic block diagram of a multi-turn magnetic sensing system that also includes quadrant detection according to an embodiment.

[0038] Figure 5A is a schematic diagram of two multi-turn sensors of a multi-turn magnetic sensing system according to an embodiment.

[0039] Figure 5B-1 , 5B-2 and 5B-3 is a table summarizing the behavior of the multi-turn magnetic sensor when the magnetic field rotates, the multi-turn magnetic sensor is reset, and the index value is updated. Figure 5A The sensor status, index value, and number of turns of a multi-turn magnetic sensing system.

[0040] Figure 6 is a schematic block diagram of a multi-turn magnetic sensing system with flip counting according to an embodiment.

[0041] Figure 7 is a schematic block diagram of a multi-turn magnetic sensing system with flip counting and angle sensing according to an embodiment.

[0042] Figure 8 A schematic block diagram of an embodiment of a multi-turn magnetic sensing system with flip counting and a single multi-turn magnetic sensor. DETAILED DESCRIPTION

[0043] The following detailed description of certain embodiments presents various descriptions of specific embodiments. However, the innovations described herein may be embodied in a variety of different ways, for example, as defined and covered by the claims. In this specification, reference is made to the accompanying drawings in which the same reference numerals may represent identical or functionally similar elements. It should be understood that the elements shown in the drawings are not necessarily drawn to scale. In addition, it should be understood that certain embodiments may include more elements and / or a subset of the elements shown than shown in the figures. In addition, some embodiments may combine any suitable combination of features from two or more of the drawings. Headings are provided for convenience only and do not affect the scope or meaning of the claims.

[0044] Multi-turn magnetic sensor

[0045] Multi-turn magnetic sensors can continuously detect rotational or linear motion without power and can read absolute position when powered. Multi-turn magnetic sensors can provide true power-on capability without receiving power. Multi-turn magnetic sensors can work on the principle of magnetic spirals or tracks, detecting motion in the presence of a moving permanent magnet. The magnetic spirals can include nanowires. The magnetic spirals can include giant magnetoresistive (GMR) materials. The resistance of the magnetoresistive element of the magnetic spiral can change as the magnetic spiral fills domain walls, which can also be called magnetic domains, in response to the rotation of the magnetic field. This effect can be called shape anisotropy. The number of turns can be decoded from the resistance of the magnetoresistive element of the multi-turn magnetic sensor. The turn count can be combined with the angle detected by the angle sensor to provide absolute multi-turn position information.

[0046] The technical challenge of multi-turn magnetic sensors is to initialize and / or reset the multi-turn magnetic sensors in the middle of the measuring range. The present invention provides a technical solution to this challenge.

[0047] Another technical challenge associated with multi-turn magnetic sensors is that the number of turns counted by the multi-turn sensor may be limited by the number of turns of the magnetic spiral of the multi-turn magnetic sensor. In various applications, it may be desirable for the multi-turn magnetic sensor to continue counting beyond the limit on the number of turns based on the physical geometry of the magnetic spiral. The present disclosure provides a technical solution related to counting the number of magnetic field turns that exceeds the limit imposed by the physical geometry of the magnetic spiral of the multi-turn magnetic sensor.

[0048] Reset multi-turn magnetic sensor

[0049] The multi-turn magnetic sensor may be reset by applying a magnetic field having an amplitude higher than the upper magnetic limit of the multi-turn magnetic sensor. This may cause the magnetic spiral of the multi-turn magnetic sensor to be filled with domain walls. Such a reset may correspond to the multi-turn magnetic sensor being in a maximum turns state. In some other applications, resetting the magnetic spiral of the multi-turn magnetic sensor may cause the multi-turn magnetic sensor to be in a minimum turns state, where the magnetic spiral has no domain walls.

[0050] The magnetic spiral can take the form of a clockwise (CW) sensor or a counterclockwise (CCW) sensor. A CW multi-turn magnetic sensor can count the number of turns in the presence of a magnetic field rotating in a CW direction. In such a multi-turn magnetic sensor, the number of turns can correspond to a magnetoresistive element of a magnetic spiral filled with domain walls. The magnetoresistive element can be a leg of the magnetic spiral. A CCW multi-turn magnetic sensor can count the number of turns in the presence of a magnetic field rotating in a CCW direction. Domain walls propagate in the opposite direction in a CW multi-turn magnetic sensor relative to a CCW multi-turn magnetic sensor.

[0051] If the CW sensor is magnetically reset by filling the domain walls, the CW sensor can be in a state corresponding to the maximum number of turns. Starting from the state corresponding to the maximum number of turns, the CW sensor can only detect multi-turn motion in the presence of a magnetic field rotating in the CCW direction. Similarly, after the CCW sensor is magnetically reset to a state filled with domain walls, the CCW sensor can only detect multi-turn motion in the presence of a magnetic field rotating in the CW direction.

[0052] Mid-position reset of multi-turn magnetic sensors

[0053] Aspects of the present disclosure relate to resetting a multi-turn magnetic sensor to a reset state, the reset state corresponding to a number of turns between a first value and a second value of a range of turns corresponding to states of two multi-turn magnetic sensors. The first value may be a minimum value of the turn count range, and the second value may be a maximum value of the range. Thus, the multi-turn magnetic sensing system can track CW rotation of a magnetic field from the reset state, and track CCW rotation of a magnetic field from the reset state.

[0054] The multi-turn magnetic sensing system may include two multi-turn magnetic sensors, a CW multi-turn magnetic sensor and a CCW multi-turn magnetic sensing sensor. Domain walls may propagate in opposite directions in the CW multi-turn sensor and the CCW multi-turn magnetic sensor. Both the CW multi-turn magnetic sensor and the CCW multi-turn magnetic sensor may be reset to a reset state during an initialization phase. The reset state may correspond to both multi-turn magnetic sensors being filled with domain walls.

[0055] Starting from a reset state, the multi-turn magnetic sensing system can count the cumulative number of turns in the CW direction and / or the CCW direction. If the magnetic field rotates in the CW direction from the reset state, the CCW sensor counts down from N to 0, where N is the maximum number of turns. At the same time, the CW sensor can remain in its maximum N-turn state. Similarly, if the magnetic field rotates in the CCW direction from the reset state, the CW sensor can count down from N to 0, where N is the maximum number of turns. At the same time, the CCW sensor can remain in its maximum N-turn state.

[0056] Figure 1A is a schematic diagram of two multi-turn sensors of a multi-turn magnetic sensing system according to an embodiment. Figure 1B is the summary of the magnetic field rotation Figure 1A Table of the status and number of turns of a multi-turn magnetic sensing system. Figure 1A A multi-turn magnetic sensing system 10 having a CW sensor and a CCW sensor with magnetic reset capability is shown, the system being capable of measuring + / - N turns of a rotating magnetic field with a mid-range magnetic reset.

[0057] See also Figure 1A , the multi-turn magnetic sensing system 10 includes a first magnetic spiral 12 and a second magnetic spiral 14. The magnetic spirals 12 and 14 each implement their own multi-turn magnetic sensors. The magnetic spirals 12 and 14 each include a plurality of magnetoresistive elements 15 arranged in series with each other. Each side of the magnetic spirals 12, 14 between consecutive corners of the magnetic spirals 12, 14 includes a magnetoresistive element 15. The magnetic spirals 12 and 14 each include 6 turns and 24 magnetoresistive elements 15. The magnetic spirals 12 and 14 each may include a domain wall generator 16 at one end of the spiral. In some applications, the first magnetic spiral 12 and the second magnetic spiral 14 may be on a single die. Alternatively, the first magnetic spiral 12 and the second magnetic spiral 14 may be on different molds.

[0058] The multi-turn magnetic sensing system 10 can count + / - 3 turns of magnetic field starting from a reset state. The reset state can correspond to the number of turns between the end points of the counting range. For example, in the multi-turn magnetic sensing system 10, the reset state can correspond to the midpoint of the counting range. For a + / - 3 counting range, the first magnetic spiral 12 and the second magnetic spiral 14 can each have a measurement range of 6 turns. For example, Figure 1AAs shown, the first magnetic spiral 12 can count 6 turns of magnetic field in the CW direction, and the second magnetic spiral 14 can count 6 turns of magnetic field in the CCW direction. In the multi-turn magnetic sensing system 10, the reset state can correspond to the midpoint of the turn range. This may be because the first magnetic spiral 12 and the second magnetic spiral 14 have the same number of turns.

[0059] In this disclosure, a CW turn is denoted as a positive turn and a CCW turn is denoted as a negative turn. The opposite convention of a CCW turn as a positive turn and a CW turn as a negative turn can be used to describe the same function.

[0060] Will refer to Figure 1B The operation of the multi-turn magnetic sensing system 10 is discussed. The first magnetic spiral 12 and the second magnetic spiral 14 can be reset. This can fill each magnetic spiral 12, 14 with a domain wall. In the reset state, the first magnetic spiral 12 and the second magnetic spiral 14 can both be in a maximum state, which is 6 in this example. The number of turns of the multi-turn magnetic sensing system 10 can represent the cumulative number of turns starting from the reset state. Therefore, for the reset state, the number of turns is 0. This state can be a system state A of the multi-turn magnetic sensing system 10.

[0061] When the magnetic field rotates three full circles clockwise, the number of turns of the second magnetic spiral 14 can be reduced, while the state of the first magnetic spiral 12 can remain unchanged. For every clockwise rotation of the magnetic field, the number of turns of the multi-turn magnetic sensing system 10 can increase by one. Figure 1B In the figure, the states of the multi-turn magnetic sensing system 10 after one full clockwise rotation starting from the reset state, one full counterclockwise rotation ending from the reset state, and three full clockwise rotations stopping from the reset state are B, C, and D, respectively.

[0062] When the magnetic field rotates three full turns clockwise, the number of turns of the second magnetic spiral 14 can be reduced, while the number of turns of the first magnetic spiral 12 remains unchanged. For every clockwise rotation of the magnetic field, the number of turns of the multi-turn magnetic sensing system 10 can be increased by one. Figure 1B In the figure, the states of the multi-turn magnetic sensing system 10 after one full clockwise rotation starting from the reset state, one full counterclockwise rotation ending from the reset state, and three full clockwise rotations stopping from the reset state are B, C, and D, respectively.

[0063] Starting from system state D, the magnetic field can rotate counterclockwise for 3 turns. The number of turns of the first magnetic spiral 12 can decrease, while the number of turns of the second magnetic spiral 14 can increase. For each CCW full rotation of the magnetic field, the number of turns of the multi-turn magnetic sensing system 10 can decrease by 1. After these full CCW magnetic field rotations starting from system state D, the states of the multi-turn magnetic sensing system 10 are E, F, and G, respectively. In state G of the system, after 3 CW and CCW rotations from the reset state, the system turns return to 0.

[0064] The magnetic field can rotate CW for another 3 turns, wherein the number of turns of the first magnetic spiral 12 can be reduced and the number of turns of the second magnetic spiral 14 can be increased.

[0065] After the magnetic field rotates three times cumulatively in each direction from the reset state, the multi-turn magnetic sensing system 10 can operate in a balanced manner. Figure 1B The first system state K and subsequent states correspond to a multi-turn magnetic sensing system 10 operating in equilibrium. Once equilibrium is reached, the multi-turn magnetic sensing system 10 operates in one of seven system states of full turns of the magnetic field, where these system states correspond to full turn counts from -3 to +3. The seven system states are Figure 1B The states J, K, L, M, N, O and P in the pre-processing circuit and decoder can be used to decode the valid pre-balance state for counting. Figure 1B In , states A, B, C, D, E, F, G, H, and I are valid pre-balance states from which the number of turns of the system can be decoded.

[0066] like Figure 1B As shown, the multi-turn magnetic sensing system 10 can have multiple system states corresponding to the same number of turns. For example, there may be a pre-equilibrium state and a balanced state, both of which correspond to the same number of turns. As an example, system states H and L both correspond to a number of turns of -1. As another example, system states B, F, and N each correspond to a number of turns of 1. This example illustrates that multiple pre-equilibrium states can correspond to the same number of turns as one balanced state.

[0067] exist Figure 1B , 16 system states (i.e., states A to P) corresponding to a full turn from a reset state are shown. Other valid states are possible for the multi-turn magnetic sensing system 10. Other valid states may be a pre-balanced state. As an example of another valid state, 1 CCW rotation from a reset state is another possible valid state.

[0068] The operation of the multi-turn magnetic sensing system 10 is discussed above with reference to a full rotation of the magnetic field. In accordance with any suitable principles and advantages disclosed herein, the multi-turn magnetic sensing system 10 can track turns at different resolutions. For example, the decoder can determine the number of turns from the output signal associated with the first magnetic spiral 12 and / or the second magnetic spiral 14 at a half-turn resolution or a quarter-turn resolution. Using the half-turn resolution, there can be an intermediate state between any two consecutive states associated with a full turn, where the intermediate state can correspond to a half turn between two consecutive full-turn states. Using the quarter-turn resolution, there can be 3 intermediate states between any two consecutive states associated with a full turn, where the intermediate states can correspond to a quarter turn, a half turn, and three quarters of a turn.

[0069] refer to Figure 1AAny suitable principles and advantages disclosed in and / or 1B can be applied to a multi-turn magnetic sensing system that can count + / -N turns, where the CW sensor and CCW sensor each have a measurement range of 2N turns. By flipping the count and index, reference Figure 1A Any suitable principles and advantages disclosed in and / or 1B may be applied to a multi-turn magnetic sensing system with flip count, where the number of turns may have a value greater in magnitude than the number of turns of a single multi-turn magnetic sensor.

[0070] Although the magnetic spirals 12 and 14 are configured to count the same number of turns as each other, reference Figure 1A Any suitable principles and advantages disclosed in and / or 1B can be applied to two magnetic spirals that can count different numbers of turns. For two magnetic spirals that can count different numbers of turns, the reset state may not be at the exact midpoint of the system turn range.

[0071] Multi-turn magnetic sensing system with mid-position reset

[0072] The intermediate position reset can be implemented in various multi-turn magnetic sensing systems. Such multi-turn magnetic sensing systems can include Figure 1A Additional hardware other than that shown. For example, the multi-turn magnetic system may include processing circuitry and a magnetic reset. The processing circuitry may include signal conditioning circuitry and a controller. In some applications, the multi-turn magnetic system may include one or more additional sensors, such as an angle sensor and / or a quadrant detector. Figures 2 to 4 An example multi-turn magnetic sensing system with intermediate position reset is discussed.

[0073] Figure 2 is a schematic block diagram of a multi-turn magnetic sensing system 20 according to an embodiment. The multi-turn magnetic sensing system 20 can track and output a number of turns, which represents the number of turns of a magnetic field that can be generated by the rotation of a magnetic target 21 or other magnetic field source. As shown, the magnetic target 21 can be a dipole magnet. In some applications, the magnetic target 21 can be mounted on a rotating shaft. The multi-turn magnetic sensing system 20 includes a first multi-turn magnetic sensor 22, a second multi-turn magnetic sensor 24, a signal conditioning circuit 25, a controller 26, and a magnetic reset 27.

[0074] The first multi-turn magnetic sensor 22 is a CW sensor. The second multi-turn magnetic sensor 24 is a CCW sensor. The multi-turn magnetic sensors 22 and 24 can each include a magnetic spiral. Example magnetic spirals are as follows: Figure 1A The multi-turn magnetic sensors 22 and 24 may include magnetic spirals configured to track any suitable number of turns for a particular application.

[0075] The output signals from the first multi-turn magnetic sensor 22 and the second multi-turn magnetic sensor 24 are conditioned by the signal conditioning circuit 25. The signal conditioning circuit 25 may include any suitable circuit to modify the raw analog output signals from the multi-turn magnetic sensors 22 and 24 so that the signals are suitable for further processing. The signal conditioning circuit 25 may include one or more amplifiers and / or one or more filters. The signal conditioning circuit 25 may include a readout circuit 28 that reads out values ​​associated with the magnetoresistive elements of the multi-turn magnetic sensors 22 and 24. In certain applications, the readout circuit 28 may be implemented according to any suitable principles and advantages disclosed in U.S. Patent No. 10782153, the disclosure of which is incorporated herein by reference in its entirety for all purposes. The signal generated by the readout circuit 28 may indicate the resistance of one or more magnetoresistive elements of the first multi-turn magnetic sensor 22 or the second multi-turn magnetic sensor 24.

[0076] The controller 26 may include a decoder 29 that may determine the accumulated number of turns of the magnetic field based on the output signal of the signal conditioning circuit 25. The controller 26 may digitize the output signal from the signal conditioning circuit 25 using an analog-to-digital converter (ADC). The digital output signal from the ADC may be provided to the decoder 29 for determining the number of turns. For example, the controller 26 may output the number of turns to a user interface. The user interface may be any suitable interface, including but not limited to an inter-integrated circuit (I²C) interface or a serial peripheral interface (SPI). The controller 26 may generate a control signal to control the magnetic reset 27.

[0077] The decoder 29 may output a number of turns representing the cumulative number of turns of the magnetic field. The decoder 29 may determine any suitable value from, for example, Table 1B. For example, the decoder 29 may determine the state and number of turns of the multi-turn magnetic sensors 22 and 24. The decoder 29 may determine the state of the first multi-turn magnetic sensor 22 and the second multi-turn magnetic sensor 24 based on the output signal from the readout circuit 28. The state of the first multi-turn magnetic sensor 22 may be determined based on a signal representing the resistance of the magnetoresistive element of the first multi-turn magnetic sensor 22. Similarly, the state of the second multi-turn magnetic sensor 24 may be determined based on a signal representing the resistance of the magnetoresistive element of the first multi-turn magnetic sensor 24. The decoder 29 may receive a digital input signal and provide the number of turns as a digital output signal. In some applications, the decoder 29 may implement successive approximation decoding to determine the state of a single multi-turn magnetic sensor 22 or 24. Such decoding may be implemented according to any suitable principles and advantages disclosed in U.S. Patent No. 10830613, the entire contents and all purposes of which are incorporated herein by reference.

[0078] The decoder 29 may determine the number of turns based on the states of the multi-turn magnetic sensors 22 and 24 . Figure 1BAn example mapping of revolutions to sensor states is provided in . In decoding the output signal from the readout circuit 28, the decoder 29 can decode the valid pre-balanced state and the valid balanced state. The decoder 29 can be a full-turn decoder, a half-turn decoder, or a quarter-turn decoder.

[0079] The controller 26 can control the magnetic resetter 27 to reset the multi-turn magnetic sensors 22 and 24 to a reset state. Such a magnetic reset can be performed when the system is initialized. In this case, the reset state can be an initialization state. In some applications, the magnetic reset can be performed in response to detecting a system fault, for flip count (discussed in more detail below), periodically after reaching a threshold amount of time for system operation, or in response to detecting one or more of any other suitable conditions.

[0080] The magnetic reset device 27 may include any suitable structure to reset the multi-turn magnetic sensors 22 and 24. In some applications, the magnetic reset 27 may include a coil that can generate a reset magnetic field greater than the upper limit of the operation of the multi-turn magnetic sensors 22 and 24. The controller 26 may cause a current to flow through the coil to generate the reset magnetic field. The coil may fill the multi-turn magnetic sensors 22 and 24 with domain walls to cause the multi-turn magnetic detectors 22 and 24 to enter a reset state. The coil may be implemented on a printed circuit board. In some other applications, the magnetic reset 27 may include a permanent magnet that is brought into physical proximity to the multi-turn magnetic sensors 22 and 24 to apply a magnetic field greater than the upper limit of the operation of the multi-turn magnetic sensors 22 and 24. For such a permanent magnet, the controller 26 may provide a control signal to move the permanent magnet to a position close enough to the multi-turn magnetic sensors 22 and 24 to cause them to enter a reset state. The controller 26 may then move the permanent magnet away from the multi-turn magnetic sensors 22 and 24 to allow the multi-turn magnetic sensing system 20 to track the rotation of the magnetic field.

[0081] Figure 3 is a schematic block diagram of a multi-turn magnetic sensing system 30 including an angle sensor 32 according to an embodiment. The multi-turn magnetic sensing system 30 is similar to Figure 2 The multi-turn magnetic sensing system 20 may include an angle sensor 32 in addition to the multi-turn magnetic sensing system 30 , and the processing circuit of the multi-turn magnetic sensing system 30 may combine the angle and the number of turns to generate a position measurement value.

[0082] The angle sensor 32 can detect a magnetic angle associated with a magnetic field. The angle sensor 32 can be a magnetic sensor, such as, but not limited to, an anisotropic magnetoresistive (AMR) sensor or another type of magnetoresistive sensor. As an example, the angle sensor 32 can include a half bridge of two magnetoresistive elements. The angle can be determined from the angle sensor 32. For example, the signal conditioning circuit 25 can condition the output signal of the angle sensor 32, and the controller 26 can determine the angle based on the conditioned output signal of the angle sensor 32. The angle can be in the range of 0° to 360°. The angle can be determined with any suitable accuracy, such as within 1°, within 0.5°, or within 0.25°.

[0083] The controller 26 can combine the turn count and angle to generate a position measurement. The position measurement can represent the number of turns and angles of the magnetic field rotation from the reset state. For example, when the number of turns is two and the angle is 14°, the position measurement value is 734°. The resolution of the position measurement is higher than the number of turns. In some applications, the accuracy of the position measurement can reach ±0.25°.

[0084] Processing circuitry of the multi-turn magnetic sensing system 30 (e.g., circuitry of the controller 26) may compensate for phase shifts between signals associated with the angle sensor and the multi-turn sensor, for example, based on any suitable principles and advantages disclosed in U.S. Pat. No. 10,859,406, the disclosure of which is incorporated herein by reference in its entirety for all purposes.

[0085] Figure 4 is a schematic block diagram of a multi-turn magnetic sensing system 30 including a quadrant detector 42 according to an embodiment. The multi-turn magnetic sensing system 40 is similar to Figure 3 The multi-turn magnetic sensing system 40 further includes a quadrant detector 42, and a processing circuit of the multi-turn magnetic sensing system 40 may combine quadrant information with the number of turns and / or angle information.

[0086] The quadrant detector 42 can detect a quadrant associated with the magnetic field. The angle sensor 42 can be a magnetic sensor, such as, but not limited to, an anisotropic magnetoresistive (AMR) sensor or another type of magnetoresistive sensor. The quadrant can be determined from the quadrant detector 42. For example, the controller 26 can determine the quadrant based on the output signal from the quadrant detector 42 conditioned by the signal conditioning circuit 25. The controller 26 can use the quadrant information to increase safety and / or redundancy. The controller 26 combines the quadrant with the turn count to generate a position measurement and / or verify the turn count and / or position measurement. In some cases, the multi-turn magnetic sensing system may include the multi-turn magnetic sensors 22 and 24 and the quadrant detector 42, but not the angle sensor 32.

[0087] Multi-turn magnetic sensing with flip counting

[0088] Aspects of the present disclosure relate to a flip count exceeding a number of turns associated with a number of turns of a magnetic track of a multi-turn magnetic sensor. Through flip counts, a multi-turn magnetic sensor system can continuously count the number of rotations of a magnetic field exceeding a number of turns associated with a physical geometry of a multi-turn magnetic sensor of the multi-turn magnetic sensing system. The number of turns associated with the physical geometry can be referred to as sensor turns. When the multi-turn magnetic sensor reaches a value at the end of a sensor turns range, the multi-turn magnetic sensor of the system can be reset and an index value can be stored in a memory of the system. In a subsequent turns decoding, the system can determine the number of turns based on the state of the multi-turn magnetic sensor and the index value.

[0089] In some embodiments, the multi-turn magnetic sensor includes a magnetic spiral having N turns, where N is a positive integer greater than 1. The index value can be updated in association with resetting the multi-turn magnetic sensor. The number of turns can be determined based on the output signal of the multi-turn magnetic sensor and the index value, and the number of turns can have a value greater than N. The number of turns can also be determined based on the output signal of a second multi-turn magnetic sensor, in which the domain wall propagates in an opposite direction compared to the multi-turn magnetic sensor.

[0090] The ability to continue counting beyond the number of turns associated with the physical geometry of the multi-turn magnetic sensor can be achieved by a system including two multi-turn magnetic sensors and a magnetic reset system, wherein the two multi-turn magnetic sensors include a CW sensor and a CCW sensor. The magnetic reset can be implemented according to any suitable principles and advantages of the magnetic reset disclosed herein.

[0091] Both CW and CCW sensors can be magnetically reset (e.g., to fill domain walls) during the initialization phase. If the magnetic field is rotated in the CW direction from the reset state, the CCW sensor can be active and count down from N to 0, where N is the maximum number of turns of the sensor, while the CW sensor can remain in its N-max-turns static state. Similarly, if the magnetic field is rotated in the CCW direction from the reset state, the CW sensor can be active and count down from N to 0, where N is the maximum number of turns of the sensor, while the CCW sensor can remain in its N-max-turns static state.

[0092] Applying a magnetic reset each time the active sensor reaches 0 turns allows for continuous counting. After reset, as rotation continues, the number of turns can be indexed up or down as needed when the active sensor state changes from N to N-1. The updated index value can be stored to memory.

[0093] When a static sensor set to N turns changes state, a change in rotation direction can be detected. When a static sensor changes phase, the previously static sensor can count down from N to 0, while the previously active sensor can count in the opposite direction.

[0094] A magnetic reset may be applied in response to the previously active sensor reaching N turns after a direction change. After reset, the index value may be updated in the opposite direction when the newly activated sensor state changes from N to N-1. The newly activated sensor may be reset when it reaches 0 turns.

[0095] Figure 5A is a schematic diagram of two multi-turn sensors of a multi-turn magnetic sensing system according to an embodiment. Figure 5B-1 , 5B-2 and 5B-3 is a table summarizing the behavior of the multi-turn magnetic sensor when the magnetic field rotates, the multi-turn magnetic sensor is reset, and the index value is updated. Figure 5A The sensor status, index value, and number of turns of a multi-turn magnetic sensing system. Figure 5A A multi-turn magnetic sensing system 50 is shown having a 10-turn CW sensor and a 10-turn CCW sensor with magnetic reset capability and index tracking.

[0096] See also Figure 5A , a multi-turn magnetic sensing system 50 includes a first magnetic spiral 52 and a second magnetic spiral 54. Each of the magnetic spirals 52 and 54 implements a multi-turn magnetic sensor. The magnetic spirals 52 and 54 each include a plurality of magnetoresistive elements 15 arranged in series with each other. Each side of the magnetic spirals 52, 54 between consecutive angles of the corresponding magnetic spirals 52, 54 includes a magnetoresistive element 15. Each of the magnetic spirals 52 and 54 includes 10 turns and 40 magnetoresistive elements 15. Any suitable principles and advantages of flip counting disclosed herein can be applied to magnetic spirals having any suitable number of turns. Each of the magnetic spirals 52 and 54 can include a domain wall generator 16 at one end of the spiral.

[0097] By magnetic resetting and indexing, the multi-turn magnetic sensing system 50 can count the rotation of the magnetic field in the CW and CCW directions for more than a single magnetic spiral 52, 54 turns. Figure 5B-1 , 5B-2 The tables 5B-3 and 5B-4 summarize the operation of the multi-turn magnetic sensing system 50 at various rotations of the magnetic field, with the initial state being -23 turns to 27 turns. In this example, the multi-turn magnetic sensing system 50 can track the number of turns using the state of the magnetic spirals 52 and 54 and the index value. The index value is stored in the memory of the multi-turn magnetic sensing system 50. The multi-turn magnetic sensing system 50 can count any suitable number of turns in the CW direction and any suitable number of turns in the CCW direction.

[0098] As described above, in this disclosure, a CW turn is indicated as a positive turn and a CCW turn is indicated as a negative turn. The opposite convention of a CCW turn as a positive turn and a CW turn as a negative turn can be used to describe the same function.

[0099] Will refer to Figure 5B-1 , 5B-25B-3 discuss the operation of the multi-turn magnetic sensing system 50. The first magnetic spiral 52 and the second magnetic spiral 54 can be reset to an initialization state. This can fill each magnetic spiral 52, 54 with a domain wall. In the initialization state, the first magnetic spiral 52 and the second magnetic spiral 54 can both be at a maximum state, which is 10 in this example. The number of turns of the multi-turn magnetic sensing system 50 can represent the cumulative number of turns starting from the initialization state. For the initialization state, the number of turns is 0. As Figure 5B-1 As shown, the initialization state corresponds to a turn number of 0. The initialization state also corresponds to Figure 5B-1 In response to detecting a rotation of the magnetic field from the initialization state, the index is updated. For example, in this example, in response to detecting a CW rotation of the magnetic field from the initialization state, the index is incremented from 0 to 1.

[0100] When the magnetic field rotates clockwise for 9 full turns, the number of turns of the second magnetic spiral 54 can decrease, while the state of the first magnetic spiral 52 can remain unchanged. For every clockwise rotation of the magnetic field, the number of turns of the multi-turn magnetic sensing system 50 can increase by 1. During this CW rotation, the second magnetic spiral 54 is active, while the first magnetic spiral 52 is stationary.

[0101] After the magnetic field rotates a number of complete CW rotations corresponding to the number of turns of the second magnetic spiral 54, the magnetic spiral 54 can be magnetically reset. In the multi-turn magnetic sensing system 50, the second magnetic spiral 54 is reset after the magnetic field rotates 10 full turns clockwise from the reset state. The magnetic spirals 52 and 54 can be reset to the reset state. Since the index value is non-zero, the reset state may be different from the initialization state. For example, in Figure 5B-1 In the reset state, corresponding to 10 turns, the states of the magnetic spirals 52 and 54 are both 10, and the index value is 1. When the reset state corresponds to 0 turns, the reset state may be the same as the initialization state. For example, Figure 5B-2 The reset state corresponding to 0 turns is the same as the initialization state.

[0102] After reset, the second magnetic spiral 54 can continue to adjust its number of turns and act as an active sensor when the magnetic field rotates in the CW direction. The index value can be adjusted in association with the magnetic reset. The index value can be updated before, during, or after the magnetic reset to track the number of turns associated with the magnetic reset. In some applications, the index value can be adjusted after reset. For example, Figure 5B-1 and 5B-2 As shown, after reset, the index value can be updated corresponding to a full turn. After reset in various applications, the index value can be updated corresponding to less than a full turn (e.g., a quarter turn, a half turn, a three-quarter turn, etc.). In some other implementations, the index value can be updated before or during the magnetic reset.

[0103] The multi-turn magnetic sensing system 50 can detect changes in the direction of rotation of the magnetic field. In response to the change in the direction of rotation of the magnetic field, the static sensor can change state and the magnetic spirals 52 and 54 can count in opposite directions. For example, Figure 5B-2 It is shown that after the magnetic field rotation direction changes, the first magnetic spiral 52 can change from 10 turns to 9 turns, and the second magnetic spiral 54 can change from 3 turns to 4 turns, for a full CCW rotation. This shows that a previously static sensor can be activated with a change in rotation direction. When both magnetic spirals 52 and 54 have an active state different from their respective reset states, this can indicate that there is a change in rotation direction within half a turn of the magnetic spirals 52, 54.

[0104] As the magnetic field rotates CCW, the number of turns of the first magnetic spiral 52 can decrease, while the number of turns of the second magnetic spiral 54 can increase. The magnetic spirals 52 and 54 can be reset as the magnetic field rotates CCW, so that the magnetic spiral 52 or 54 reaches an end point (for example, Figures 5B-1 to 5B-3 For example, a magnetic reset may be performed in association with the second magnetic spiral 54, the magnetic reset reaching the same Figure 5B-2 In some other applications where the magnetic field transitions from CW rotation to CCW rotation and the count of the second spiral is closer to the maximum count value than the minimum count value, a magnetic reset may be performed in association with the first magnetic spiral 52 reaching the minimum number of turns.

[0105] The index can be updated in association with the magnetic reset. When the magnetic field changes from CW rotation to CCW rotation and then performs a magnetic reset, the index value can be reduced. For a magnetic reset associated with CW rotation and a magnetic reset associated with CCW rotation, the index value can be adjusted in opposite directions.

[0106] When the magnetic field rotates CCW after resetting, the number of turns of the first magnetic spiral 52 can be reduced, while the state of the second magnetic spiral 54 can remain unchanged. For each CCW full rotation of the magnetic field, the number of turns of the multi-turn magnetic sensing system 50 can be reduced by 1. During this CCW rotation, the first magnetic spiral 52 is active and the second magnetic spiral 54 is stationary.

[0107] Magnetic spiral 54 may be magnetically reset after the magnetic field rotates a number of CCW turns corresponding to the number of turns of first magnetic spiral 52. In multi-turn magnetic sensing system 50, first magnetic spiral 52 is reset after the magnetic field rotates 10 full CCW turns from the reset state. Magnetic spirals 52 and 54 may be reset to the reset state.

[0108] After reset, when the magnetic field rotates in the CCW direction, the first magnetic spiral 52 can continue to adjust its number of turns and act as an active sensor. The indicator value can be adjusted after reset. For example, Figure 5B-2 and 5B-3As shown, the index value may decrease with reset and CCW rotation.

[0109] The multi-turn magnetic sensing system 50 can continue to count the accumulated turns of the magnetic field in the CW and CCW directions by magnetic resetting and updating the index value. The number of turns can be determined based on the state of the magnetic spirals 52 and 54 and the index value. The multi-turn magnetic sensing system 50 can count to calculate the number of turns with any suitable number of magnetic field direction changes and any suitable number of magnetic resetting.

[0110] like Figures 5B-1 to 5B-3 As shown, the multi-turn magnetic sensing system 50 can have a plurality of state combinations of magnetic tracks 52 and 54 and index values ​​corresponding to the same number of turns. For example, the number of turns of 4 corresponds to (a) a first magnetic spiral 52 having 10 turns, a second magnetic spiral 54 having 6 turns, and an index value of 1, and (b) a first magnetic spiral 52 having 4 turns, a second magnetic spiral 54 having 10 turns, and an index value of 1. As another example, the number of turns of 23 corresponds to (a) a first magnetic spiral 52 having 10 turns, a second magnetic spiral 54 having 7 turns, and an index value of 3, and (b) a first magnetic spiral 52 having 6 turns, a second magnetic spiral 54 having 7 turns, and an index value of 3.

[0111] exist Figures 5B-1 to 5B-3 , the number of turns corresponding to a full turn in the initialization state is shown. Other valid states are possible for the multi-turn magnetic sensing system 50. Other valid states may include states related to changes in rotation direction at different numbers of turns. Other valid states may correspond to Figures 5B-1 to 5B-3 Number of turns outside the table range.

[0112] The operation of the multi-turn magnetic sensing system 50 is discussed above with reference to a full rotation of the magnetic field. In accordance with any suitable principles and advantages disclosed herein, the multi-turn magnetic sensing system 50 can track turns at different resolutions. For example, the decoder can determine the number of turns from the output signals associated with the first magnetic spiral 52 and / or the second magnetic spiral 54 at a half-turn resolution or a quarter-turn resolution. Using the half-turn resolution, there can be an intermediate state between any two consecutive states associated with a full turn, where the intermediate state can correspond to a half turn between two consecutive full-turn states. Using the quarter-turn resolution, there can be 3 intermediate states between any two consecutive states associated with a full turn, where the intermediate states can correspond to a quarter turn, a half turn, and three quarters of a turn.

[0113] refer to Figure 5A And / or any suitable principles and advantages disclosed in 5B-1 to 5B-3 can be applied to a multi-turn magnetic sensing system, which includes a magnetic spiral with any suitable number of turns for multi-turn magnetic sensing.

[0114] Although the magnetic spirals 52 and 54 have the same number of turns as each other, Figure 5A And / or any suitable principles and advantages disclosed in 5B-1 to 5B-3 can be applied to two magnetic spirals having different numbers of turns.

[0115] Figure 6 is a schematic block diagram of a multi-turn magnetic sensing system 60 according to an embodiment. The multi-turn magnetic sensing system 60 can implement indexing and flip counting. This can enable the multi-turn magnetic sensing system 60 to calculate the rotation of the magnetic field in the CW direction and the CCW direction for more turns than the multi-turn sensor 22 or 24.

[0116] In the multi-turn magnetic sensing system 60, the first multi-turn magnetic sensor 22 is a CW sensor and the second multi-turn magnetic sensor 24 is a CCW sensor. The signal conditioning circuit 25 can condition the signals from the first and second multi-turn sensors 22 and 24. The multi-turn magnetic sensing system 60 includes a controller 62, which can adjust the index value and store it in the memory 64 for flip count. The index value can be updated when one of the multi-turn magnetic sensors 22, 24 reaches the maximum or minimum number of turns due to the rotation of the magnetic field. The controller 62 can control the magnetic reset to magnetically reset the multi-turn magnetic sensor 22 and / or 24 in response to one of the multi-turn magnetic sensors 22, 24 reaching the maximum or minimum number of turns due to the rotation of the magnetic field. The multi-turn magnetic sensing system 60 can count endlessly in the CW or CCW direction.

[0117] The multi-turn magnetic sensing system 60 is similar to Figure 2 The multi-turn magnetic sensing system 20 includes a controller 62 and a decoder 65, wherein the index value of the controller 62 is stored in a memory 64, and the decoder 65 is used to decode the number of turns. The memory 64 may include any suitable non-volatile memory to store the index value. The controller 62 may include a counter to update the index value.

[0118] The decoder 65 can decode the number of turns based on the signals from the first and second multi-turn magnetic sensors 22 and 24 and the index value stored in the memory 64. The decoder 65 can output the number of turns representing the accumulated number of turns of the magnetic field. The decoder 65 can decode the number of turns based on the reference value. Figures 5A to 5B-3 Any suitable principles and advantages discussed herein may be used to determine the number of turns. Figures 5B-1 to 5B-3 An example of a revolution mapping of sensor status and indicator value is provided.

[0119] The controller 65 may control the magnetic reset 27 to magnetically reset the first multi-turn magnetic field sensor 22 to a reset state in response to detecting that the rotation of the magnetic field causes the first multi-turn magnetic sensor 22 to reach an endpoint value (e.g., the maximum number of turns or the minimum number of turns of the first multi-turn magnetic sensor 22). In some cases, the magnetic reset device 27 may magnetically reset the second multi-turn magnetic sensor 24 while magnetically resetting the first multi-turn magnetic sensor 22. The controller 65 may control the magnetic reset 27 to magnetically reset the second multi-turn magnetic field sensor 24 to a reset state in response to detecting that the rotation of the magnetic field causes the second multi-turn magnetic sensor 24 to reach an endpoint value, such as the maximum number of turns or the minimum number of turns of the second multi-turn magnetic sensor 24. In some cases, the magnetic reset device 27 may magnetically reset the first multi-turn magnetic sensor 22 while magnetically resetting the second multi-turn magnetic sensor 24.

[0120] Figure 7 is a schematic block diagram of a multi-turn magnetic sensing system 70 including an angle sensor 32 according to an embodiment. The multi-turn magnetic sensing system 70 is similar to Figure 6 The multi-turn magnetic sensing system 60 includes an angle sensor 32 in addition to the multi-turn magnetic sensing system 70. The processing circuit of the multi-turn magnetic sensing system 70 can combine the angle and the number of turns to generate a position measurement value. The angle sensor 32 can be used according to the reference Figure 3 Any suitable principles and advantages discussed may be implemented.

[0121] According to reference Figure 6 and / or Figure 7 Any suitable principles and advantages discussed, the quadrant detector can be implemented using a multi-turn magnetic sensing system with flip count.

[0122] Although certain embodiments with flip counts in both CW and CCW directions are disclosed, any suitable principles and advantages of flip counts and indexes disclosed herein can be applied to a multi-turn magnetic sensing system that is arranged to count turns unidirectionally from an initialization state. Such a magnetic sensing system can count the accumulated turns of the magnetic field in either the CW direction or the CCW direction.

[0123] Figure 8 FIG. 8 is a schematic block diagram of an embodiment of a multi-turn magnetic sensing system 80 with flip count and a single multi-turn magnetic sensor 82. The multi-turn magnetic sensing system 80 is similar to Figure 6 The multi-turn magnetic sensing system 60 is a multi-turn magnetic sensing system 80, except that the multi-turn magnetic sensing system 80 includes a single multi-turn magnetic sensor 82. The multi-turn magnetic sensing system 80 accumulates the number of magnetic field turns starting from the initialization state in the CW or CCW direction depending on whether the multi-turn magnetic sensor 82 is a CCW sensor like the second multi-turn magnetic sensor 24 or a CW sensor like the first multi-turn magnetic sensor 22 and the initialization state. The controller 62 can update the index value stored in the memory 64, and the decoder 65 can update the index value stored in the memory 64 according to the reference. FIG. 5A to FIG. 7 Any suitable principles and advantages discussed herein are used to decode the number of turns, which principles and advantages are applicable to counting the accumulated number of turns of the magnetic field in the CW or CCW direction.

[0124] In certain other applications, a single multi-turn magnetic sensor can be used for flip counts in both CW and CCW directions. In response to reaching a state where the single multi-turn magnetic sensor is free of domain walls due to rotation of the magnetic field in a first direction, the single multi-turn magnetic sensor can be magnetically reset to be full of domain walls, and the index value can be updated accordingly. In response to reaching a state where the single multi-turn magnetic sensor is full of domain walls due to rotation of the magnetic field in a second direction opposite to the first direction, the single multi-turn magnetic sensor can be reset to be free of domain walls, and the index value can be updated accordingly.

[0125] Applications, terminology, and conclusions

[0126] The multi-turn magnetic sensing system disclosed herein can be implemented in any suitable application that can benefit from counting the number of turns of a rotating magnetic field. Example applications include, but are not limited to, electronic power steering (EPS) applications, such as EPS steer-by-wire actuator applications, parking lock actuators, seat belt retractors, transmission actuators, other vehicle applications, robotics and / or collaborative robotics applications, such as arm joint position tracking, rotary to linear actuator applications, wire drawing encoder applications, other industrial automation applications, etc.

[0127] In the above embodiments, sensors, circuits, systems and methods for multi-turn magnetic sensing are described in conjunction with specific embodiments. However, it should be understood that the principles and advantages of the embodiments can be applied to any other suitable sensors, circuits, systems and methods with multi-turn magnetic sensing.

[0128] Unless the context clearly requires otherwise, throughout the specification and claims, the words "include", "comprising", "having" and the like should be interpreted as inclusive and not exclusive or exhaustive; that is, in the sense of "including but not limited to". The word "coupled" or "connected" as generally used herein refers to two or more elements that can be directly connected or connected through one or more intermediate elements. Therefore, although the various schematic diagrams shown in the figures depict example arrangements of elements and components, there may be additional intervening elements, devices, features or components in actual embodiments (assuming that the functionality of the depicted circuits is not adversely affected). In addition, the words "herein", "above", "below" and words of similar meaning used in this application shall refer to the entire application, not to any particular part of this application. Where the context permits, words used in the singular or plural in the detailed description may also include the plural or singular, respectively. When referring to a list of two or more items, the word "or" is intended to cover all the following interpretations of the word: any item in the list, all items in the list, and any combination of items in the list. All numerical values ​​provided herein are intended to include similar values ​​within measurement error.

[0129] Additionally, unless specifically stated otherwise or understood otherwise in the context of use, conditional language used herein, such as "may," "might," "could," "for example," "such as," etc., is generally intended to convey that some embodiments include and other embodiments do not include certain features, elements, and / or states.

[0130] The teaching of the embodiments provided herein can be applied to other systems, not necessarily the above-mentioned systems. The elements and actions of the various embodiments described above can be combined to provide further embodiments. The actions of the methods discussed herein can be appropriately performed in any order. In addition, the actions of the methods discussed herein can be performed serially or in parallel as needed.

[0131] Although certain embodiments of the present invention have been described, these embodiments are presented only by way of example and are not intended to limit the scope of the present disclosure. In fact, the novel circuits, methods and systems described herein can be embodied in various other forms. In addition, without departing from the spirit of the present disclosure, various omissions, replacements and changes can be made to the forms of the circuits, methods, devices and systems described herein. For example, although the disclosed embodiments are presented in a given arrangement, alternative embodiments can use different components and / or circuit topologies to perform similar functions, and some elements can be deleted, moved, added, subdivided, combined and / or modified. Each of these elements can be implemented in various different ways. Any suitable combination of the elements and actions of the various embodiments described above can be combined to provide further embodiments. The attached claims and their equivalents are intended to cover forms or modifications that belong to the scope and spirit of the present disclosure. Therefore, the scope of the present invention is defined by reference to the claims.

[0132] Although the claims set forth herein are filed with the USPTO in a single-dependency format, it should be understood that any claim may depend on any prior claim of the same type unless this is clearly technically infeasible.

Claims

1. A multi-turn magnetic sensing system, comprising: a first multi-turn magnetic sensor; a second multi-turn magnetic sensor, wherein domain walls propagate in an opposite direction in the second multi-turn magnetic sensor relative to the first multi-turn magnetic sensor in response to a magnetic field; and A decoder is configured to output a number of turns based on output signals from the first multi-turn magnetic sensor and the second multi-turn magnetic sensor.

2. The multi-turn magnetic sensing system of claim 1 , wherein the decoder is configured to determine a number of turns of the first and second multi-turn magnetic sensors relative to a reset state within a range from a first value to a second value, and wherein the number of turns of the reset state is between the first value and the second value.

3. The multi-turn magnetic sensing system of claim 2, wherein the first multi-turn magnetic sensor and the second multi-turn magnetic sensor are each configured to count the same number of turns in opposite directions, and the number of turns in the reset state is a midpoint between the first value and the second value. 4 . The multi-turn magnetic sensing system of claim 2 , wherein the first multi-turn magnetic sensor and the second multi-turn magnetic sensor are both filled with domain walls in the reset state.

5. The multi-turn magnetic sensing system of claim 1 , wherein the decoder is configured to determine the number of more than one full clockwise rotation of the magnetic field from the reset state and to determine the number of more than one full counterclockwise rotation of the magnetic field from the reset state.

6. The multi-turn magnetic sensing system of claim 1 , further comprising a magnetic reset configured to magnetically reset the first and second multi-turn magnetic sensors to the reset state, wherein the decoder is configured to determine a number of turns within a range from the first value to the second value relative to the reset state, and wherein the number of turns of the reset state has a value between the first value and the second value. 7 . The multi-turn magnetic sensing system of claim 6 , wherein the magnetic reset comprises a coil configured to apply a reset magnetic field to reset the first and second multi-turn magnetic sensors to the reset state.

8. The multi-turn magnetic sensing system of claim 6, further comprising a memory configured to store an index value, wherein the multi-turn magnetic sensing system is configured to update the index value in association with magnetically resetting the first and second multi-turn magnetic sensors, and wherein the decoder is configured to generate a number of turns based on the index value and output signals from the first multi-turn magnetic sensor and the second multi-turn magnetic sensor.

9. The multi-turn magnetic sensing system of claim 1, wherein when operating in an equilibrium state, the multi-turn magnetic sensing system operates in a subset of active states of the first and second multi-turn magnetic sensors.

10. The multi-turn magnetic sensing system of claim 1 , wherein the first and second multi-turn magnetic sensors have a state having the same number of turns as that corresponding to the reset state, and the first and second multi-turn magnetic sensors are not configured to move from the state to the reset state by rotation of a magnetic field.

11. The multi-turn magnetic sensing system of claim 1 , wherein the number of turns has the same value for at least two different states of the first and second multi-turn magnetic sensors.

12. The multi-turn magnetic sensing system of claim 1 further comprising an angle sensor and a processing circuit configured to output a position measurement, wherein the position measurement is based on the number of turns and the angle, and wherein the angle is based on an output signal of the angle sensor.

13. A multi-turn magnetic sensing system with mid-range reset function, comprising: a first multi-turn magnetic sensor; a second multi-turn magnetic sensor, wherein domain walls propagate in opposite directions in the second multi-turn magnetic sensor and the first multi-turn magnetic sensor in response to a magnetic field; and A decoder is configured to output a number of turns associated with states of the first multi-turn magnetic sensor and the second multi-turn magnetic sensor, wherein the number of turns is in a range from a minimum value to a maximum value relative to a reset state, and wherein the number of turns in the reset state is between the minimum value and the maximum value. 14 . The multi-turn magnetic sensing system of claim 13 , further comprising a magnetic resetter configured to magnetically reset the first and second multi-turn magnetic sensors to the reset state.

15. A multi-turn magnetic sensing method with mid-range reset, the method comprising: resetting the first multi-turn sensor and the second multi-turn sensor to a reset state, wherein domain walls propagate in opposite directions in the first multi-turn sensor and the second multi-turn sensor in response to rotation of the magnetic field; detecting a first non-zero number of turns of a magnetic field from a reset state based on first values ​​read from the first multi-turn sensor and the second multi-turn sensor, the first non-zero number of turns indicating an accumulated rotation of the magnetic field in a clockwise direction from the reset state; and Based on second values ​​read from the first and second multi-turn sensors, a second non-zero number of turns of the magnetic field relative to the reset state is detected, the second non-zero number of turns indicating an accumulated rotation of the magnetic field in a counterclockwise direction from the reset state.

16. The method of claim 15, further comprising generating a position measurement based on the number of turns and the angle information. 17 . The method of claim 15 , wherein the first multi-turn sensor and the second multi-turn sensor each include a magnetic spiral having the same number of turns.

18. The method of claim 15, wherein in the reset state, the first multi-turn sensor and the second multi-turn sensor are both filled with domain walls.

19. The method according to claim 15, further comprising: In response to the magnetic field rotating a certain number of turns, magnetically resetting the first multi-turn sensor; updating an index value stored in a memory in association with the magnetic reset; and After the update and additional rotation of the magnetic field, the number of turns is determined based on the index value and a third value is read out from the first multi-turn sensor and the second multi-turn sensor.

20. The method of claim 15, further comprising generating a position measurement based on turns and angle information associated with the magnetic field.

21. A multi-turn magnetic sensing method with flip counting, the method comprising: resetting a multi-turn magnetic sensor to a reset state, wherein the multi-turn magnetic sensor comprises a magnetic spiral having N turns, and wherein N is a positive integer greater than 1; updating an index value associated with the reset; and A number of turns is determined based on an output signal from the multi-turn magnetic sensor and the index value, wherein the number of turns has a value having a magnitude greater than N.

22. The method of claim 21, wherein the resetting comprises applying a reset magnetic field to the multi-turn magnetic sensor using a coil.

23. The method of claim 21, wherein the resetting comprises moving a permanent magnet proximate the multi-turn magnetic sensor.

24. The method of claim 21, wherein the determining is further based on an output signal from a second multi-turn magnetic sensor, and wherein domain walls propagate in an opposite direction in the second multi-turn magnetic sensor compared to the multi-turn magnetic sensor.

25. The method according to claim 24, further comprising: generating a number of turns having a second value after performing an additional rotation of the magnetic field after determining, where the values ​​represent clockwise rotation from the initialization state, and The second value represents a counterclockwise rotation starting from the initialization state.

26. The method of claim 24, wherein the multi-turn magnetic sensor and the second multi-turn magnetic sensor are both filled with domain walls in a reset state.

27. The method of claim 21, wherein the number of turns has a quarter-turn resolution.

28. The method of claim 21, further comprising: processing an output signal from the angle sensor to generate angle information; and A position measurement is generated based on the number of turns and the angle information.

29. A multi-turn magnetic sensing system with flip count, the multi-turn magnetic sensing system comprising: A multi-turn magnetic sensor comprising a magnetic spiral having N turns, wherein N is a positive integer greater than 1; and The processing circuit includes: a memory configured to store index values; and A decoder is configured to determine a number of turns having a value greater than N in magnitude based on an output signal from the multi-turn magnetic sensor and the index value, wherein the number of turns represents a number of rotations of the magnetic field.

30. The multi-turn magnetic sensing system of claim 29, further comprising a magnetic resetter configured to magnetically reset the magnetic spiral.

31. The multi-turn magnetic sensing system of claim 30, wherein the magnetic reset comprises a coil configured to apply a reset magnetic field to magnetically reset the magnetic spiral in response to a control signal from the processing circuit.

32. The multi-turn magnetic sensing system of claim 30, wherein the processing circuit is configured to update the index value in association with magnetically resetting the magnetic spiral.

33. The multi-turn magnetic sensing system of claim 30, wherein the processing circuit is configured to update the index value in response to detecting a rotation of the magnetic field after magnetically resetting the magnetic spiral.

34. The multi-turn magnetic sensing system of claim 29, further comprising a second multi-turn magnetic sensor, the second multi-turn magnetic sensor comprising a second magnetic spiral, wherein domain walls propagate in opposite directions in the magnetic spiral and the second magnetic spiral, and wherein the decoder is configured to determine the number of turns based on an output signal from the multi-turn magnetic sensor, an output signal from the second multi-turn magnetic sensor, and the index value.

35. The multi-turn magnetic sensing system of claim 34, wherein the second magnetic spiral has N turns.

36. The multi-turn magnetic sensing system of claim 34, wherein the processing circuit is configured to detect a change in a rotational direction of the magnetic field.

37. The multi-turn magnetic sensing system of claim 34, wherein the decoder is configured to determine a second value having a magnitude greater than N as the number of turns, wherein the value represents a clockwise rotation from an initialization state, and the second value represents a counterclockwise rotation from the initialization state.

38. The multi-turn magnetic sensing system of claim 29, further comprising an angle sensor, wherein the processing circuit is configured to output a position measurement based on the number of turns and angle information from the angle sensor.

39. A multi-turn magnetic sensing system with flip counting, the multi-turn magnetic sensing system comprising: A first multi-turn magnetic sensor comprising a first magnetic spiral having N turns, wherein N is a positive integer greater than 1; a second multi-turn magnetic sensor, wherein domain walls propagate in opposite directions in the second multi-turn magnetic sensor and the first multi-turn magnetic sensor in response to a magnetic field; and A decoder is configured to output a number of turns based on the index value and state of the first multi-turn magnetic sensor and the second multi-turn magnetic sensor, wherein the decoder is configured to determine the number of turns of the magnetic field exceeding N full clockwise rotations from an initialization state, and determine the number of turns of the magnetic field exceeding N full counterclockwise rotations from the initialization state.

40. The multi-turn magnetic sensing system of claim 39, further comprising a magnetic resetter and a processing circuit, wherein the magnetic resetter is configured to magnetically reset the first multi-turn magnetic sensor to a reset state, and the processing circuit is configured to update the index value in association with the magnetic reset of the first multi-turn magnetic sensor.

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