Temperature drift resistant magnetic sensor and method of magnetic field measurement

Abstract

This application relates to a temperature-drift-resistant magnetic sensor and a magnetic field measurement method. The magnetic sensor includes: a substrate; a helical microcoil disposed on the substrate to generate a stable magnetic field environment; a plurality of magnetically sensitive units disposed at different radii of the microcoil, each magnetically sensitive unit outputting a first output signal under the influence of the magnetic field and temperature; a non-magnetically sensitive unit disposed on the microcoil, the non-magnetically sensitive unit outputting a second output signal under the influence of temperature; and a signal processing circuit connected to each of the magnetically sensitive units and the non-magnetically sensitive units, used to output a measured value based on at least one of the first and second output signals. This method can improve the measurement accuracy and reliability of the magnetic sensor.

Description

Technical Field

[0001] This application relates to the field of sensor technology, and in particular to a temperature-drift resistant magnetic sensor and a magnetic field measurement method. Background Technology

[0002] Magnetic sensors, due to their high sensitivity, wide linear range, low power consumption, and small size, have broad application prospects in fields such as magnetic field measurement, geomagnetic navigation, non-destructive testing, and power system monitoring. However, the performance stability of magnetic sensors in complex environments still faces severe challenges. In particular, changes in ambient temperature can cause zero-point drift (zero bias) in magnetic sensors, which seriously restricts their measurement accuracy and reliability. Summary of the Invention

[0003] Therefore, it is necessary to provide a magnetic sensor and magnetic field measurement method that are resistant to temperature drift, which can improve the measurement accuracy and reliability of the magnetic sensor.

[0004] In a first aspect, this application provides a temperature-drift resistant magnetic sensor, which includes:

[0005] substrate;

[0006] Spiral microcoils, mounted on a substrate, are used to generate a stable magnetic field environment;

[0007] Multiple magnetic sensing units are arranged at different radii of the micro coil, and each magnetic sensing unit outputs a first output signal under the influence of magnetic field and temperature.

[0008] A non-magnetic sensitive unit is disposed on a micro-coil, and the non-magnetic sensitive unit outputs a second output signal under the influence of temperature.

[0009] The signal processing circuit is connected to each magnetic sensing unit and non-magnetic sensing unit, and is used to output the measured value according to at least one first output signal and a second output signal.

[0010] In one embodiment, the non-magnetically sensitive unit is located in the central region of the microcoil.

[0011] In one embodiment, the magnetic sensor further includes an insulating layer; the insulating layer is disposed between each magnetic sensing element and the microcoil so that the magnetic sensing elements do not contact the microcoil and has a heat insulation function.

[0012] In one embodiment, the magnetic sensor further includes a magnetic shielding layer; the magnetic shielding layer is disposed on the side of the non-magnetically sensitive unit away from the substrate, and is used to shield the magnetic field.

[0013] In one embodiment, the number of coil turns at different radii in the microcoil increases sequentially from smallest to largest radius.

[0014] In one embodiment, a signal processing circuit is configured to perform a weighted summation of the differences between each first output signal and the second output signal, and obtain the measured value based on the summation result.

[0015] In one embodiment, the plurality of magnetic sensing units include a first magnetic sensing unit and a second magnetic sensing unit; the first magnetic sensing unit is close to the center of the microcoil, and the second magnetic sensing unit is far from the center of the microcoil.

[0016] In one embodiment, in the case of small-range measurement, the signal processing circuit is used to obtain the measured value based on the difference between the first output signal and the second output signal output by the first magnetic sensing unit.

[0017] In one embodiment, in the case of a large-range measurement, the signal processing circuit is used to obtain the measured value based on the difference between the first output signal and the second output signal output by the second magnetic sensing unit.

[0018] Secondly, this application provides a magnetic field measurement method, applied to a magnetic sensor as described in any one of the first aspects above; the method includes:

[0019] Multiple magnetic sensing units in a magnetic sensor measure multiple first output signals, and each first output signal is output by each magnetic sensing unit under the influence of magnetic field and temperature.

[0020] The non-magnetically sensitive unit in the magnetic sensor measures the second output signal, which is output by the non-magnetically sensitive unit under the influence of temperature.

[0021] The signal processing circuit in the magnetic sensor processes at least one first output signal and a second output signal to obtain the measured value.

[0022] The aforementioned magnetic sensor includes a substrate, a spiral microcoil, multiple magnetically sensitive units, non-magnetically sensitive units, and a signal processing circuit. The microcoil is disposed on the substrate to generate a stable magnetic field environment. Each magnetically sensitive unit is located at a different radius of the microcoil, and each magnetically sensitive unit outputs a first output signal under the influence of the magnetic field and temperature; in other words, the first output signal is related to both the magnetic field and temperature. The non-magnetically sensitive unit is disposed on the microcoil, and outputs a second output signal under the influence of temperature; in other words, the second output signal is only related to temperature. The signal processing circuit is connected to both the magnetically sensitive unit and the non-magnetically sensitive unit, and outputs a measurement value based on at least one first output signal and one second output signal. This method eliminates temperature drift errors in the obtained measurement value, thereby improving measurement accuracy and reliability. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a top view of a temperature-drift resistant magnetic sensor in one embodiment;

[0025] Figure 2 A top view of a temperature-drift resistant magnetic sensor in another embodiment;

[0026] Figure 3 A side view of a temperature-drift resistant magnetic sensor in one embodiment;

[0027] Figure 4 This is a schematic diagram illustrating the working principle of a temperature-drift resistant magnetic sensor in one embodiment.

[0028] Figure 5 This describes the working principle of a temperature drift resistant magnetic sensor in another embodiment;

[0029] Figure 6 This is a flowchart illustrating a magnetic field measurement method in one embodiment. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0031] Currently, there are various types of magnetoresistive magnetic sensors, such as GMR (Giant Magneto Resistance), TMR (Tunneling Magneto-Resistance), and AMR (Anisotropic Magneto-Resistance). These types of magnetic sensors have broad application prospects in fields such as magnetic field measurement, geomagnetic navigation, non-destructive testing, and power system monitoring due to their high sensitivity, wide linear range, low power consumption, and small size. TMR magnetic sensors, in particular, have attracted much attention due to their excellent performance. However, the performance stability of these magnetic sensors in complex environments still faces severe challenges. In particular, changes in ambient temperature can significantly affect the sensitivity and zero-point drift (zero bias) of the magnetic sensor, severely limiting the accuracy and reliability of magnetic field measurements.

[0032] Traditional temperature compensation methods typically rely on additional temperature sensors and processors to collect temperature information for compensation. However, this approach has the following limitations: (1) Dependence on the characteristics of the temperature sensor: Temperature sensors require high repeatability and consistency, and their measurement accuracy directly affects the effectiveness of temperature drift suppression. (2) Errors in indirect temperature measurement: Temperature sensors can only measure the temperature changes of the external environment and cannot accurately reflect the actual temperature changes inside the sensor, leading to compensation errors. (3) Dynamic response lag: When the temperature changes rapidly, the compensation system may not respond quickly enough to the temperature changes, which can easily lead to a decrease in compensation accuracy or even failure.

[0033] Furthermore, magnetic field measurement applications are diverse, leading to significant variations in the range requirements for magnetic sensors. Traditional single-range magnetic sensors struggle to simultaneously meet the demands of high sensitivity measurements over small magnetic field ranges and wide range measurements over large magnetic field ranges, thus limiting their applicability. The differences in characteristics among different types of magnetic sensing elements (such as GMR, TMR, and AMR) further complicate magnetic sensor design, making insufficient compatibility another challenge.

[0034] Therefore, traditional technologies have the following problems: (1) Insufficient multi-range design: Most magnetic sensor designs are only suitable for fixed ranges and cannot meet the measurement needs of small and large magnetic fields, resulting in insufficient flexibility of the sensor in application. (2) Limited temperature compensation capability: Traditional temperature compensation methods cannot reflect the internal temperature changes of the sensor in real time, and the problems of compensation lag and insufficient accuracy are prominent. (3) Poor compatibility: Different types of magnetic sensing units have differences in material properties and output signal characteristics, and existing solutions are difficult to achieve unified compatibility and optimization for different magnetic sensing units such as GMR, TMR, and AMR.

[0035] Therefore, it is necessary to propose effective technical means to solve the above-mentioned technical problems. The technical solution of this application and how it solves the above-mentioned technical problems will be described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will be described below with reference to the accompanying drawings.

[0036] In one embodiment, such as Figure 1 and Figure 2As shown, this application provides a top view of a temperature-drift resistant magnetic sensor. The magnetic sensor includes: a substrate 101, a spiral microcoil 102, a plurality of magnetically sensitive units 103, non-magnetically sensitive units 104, and a signal processing circuit 105. The microcoil 102 is disposed on the substrate 101 to generate a stable magnetic field environment. Each magnetically sensitive unit 103 is disposed at a different radius position of the microcoil 102, and each magnetically sensitive unit 103 outputs a first output signal under the influence of the magnetic field and temperature. The non-magnetically sensitive unit 104 is disposed on the microcoil 102, and the non-magnetically sensitive unit 104 outputs a second output signal under the influence of temperature. The signal processing circuit 105 is connected to each magnetically sensitive unit 103 and each non-magnetically sensitive unit 104, and outputs a measurement value based on at least one first output signal and one second output signal.

[0037] The substrate 101 is used to support the micro coil 102, each magnetic sensing unit 103 and non-magnetic sensing unit 104; the material of the substrate 101 can be an insulating material.

[0038] Microcoils 102 are disposed on one side of substrate 101 and distributed in a planar spiral shape. Specifically, microcoils 102 can be circular spirals or rectangular spirals. Figure 1 and Figure 2 The example is a rectangular spiral. The two ends of the microcoil 102 are connected to the positive and negative terminals of the power supply, respectively. The microcoil 102 covers the areas of each magnetically sensitive unit 103 and the non-magnetically sensitive unit 104, and is used to provide a stable magnetic field environment and perform dynamic compensation.

[0039] Multiple magnetic sensing units 103 can be disposed on the side of the microcoil 102 away from the substrate 101, and each magnetic sensing unit 103 is disposed at a different radius position of the microcoil 102. The number of magnetic sensing units 103 can be four, that is, the multiple magnetic sensing units 103 can include a pair of first magnetic sensing units and a pair of second magnetic sensing units. The pair of first magnetic sensing units is close to the center of the microcoil 102, and the pair of second magnetic sensing units is away from the center of the microcoil 102. The positions of the pair of first magnetic sensing units on the microcoil 102 are equidistant from the center of the microcoil 102, and the two first magnetic sensing units are arranged opposite each other. The positions of the pair of second magnetic sensing units on the microcoil 102 are equidistant from the center of the microcoil 102, and the two second magnetic sensing units are arranged opposite each other. Figure 2 As shown. Of course, the number of magnetic sensing units 103 can be two, that is, multiple magnetic sensing units 103 may include a first magnetic sensing unit and a second magnetic sensing unit; the first magnetic sensing unit is close to the center of the microcoil 102, and the second magnetic sensing unit is far from the center of the microcoil 102, as shown. Figure 1As shown. For example, the first magnetic sensing unit is disposed on the coil adjacent to the outermost coil in the micro coil 102, and the second magnetic sensing unit is disposed on the outermost coil of the micro coil 102.

[0040] The magnetic sensing unit 103 near the center of the microcoil 102, that is, the magnetic sensing unit 103 near the inner ring of the microcoil 102, is suitable for small-range measurement; the magnetic sensing unit 103 far from the center of the microcoil 102, that is, the magnetic sensing unit 103 near the outer ring of the microcoil 102, is suitable for large-range measurement.

[0041] In addition, the magnetic sensing unit 103 can be of the type GMR, TMR or AMR, which outputs a first output signal under the influence of magnetic field and temperature, that is, the first output signal is a signal related to magnetic field and temperature.

[0042] The number of non-magnetic sensing units 104 can be one or more. Each non-magnetic sensing unit 104 needs to be placed in the same temperature environment as the magnetic sensing unit 103 and located in the shielding area of ​​the microcoil. When there is only one non-magnetic sensing unit 104, it can be located in the central region of the microcoil 102 on the side away from the substrate 101, such as... Figure 1 As shown; when there are multiple non-magnetic sensing units 104, each non-magnetic sensing unit 104 can be arranged in a corresponding manner near each magnetic sensing unit 103, such as... Figure 2 As shown. Preferably, the number of non-magnetically sensitive units 104 is one, which is disposed in the central region of the microcoil 102 on the side away from the substrate 101, because the temperature difference at different radii on the microcoil 102 is not significant, so one non-magnetically sensitive unit 104 is sufficient.

[0043] Additionally, the non-magnetically sensitive unit 104 can be an MTJ (Magnetic Tunnel Junction) unit, which is only affected by temperature. Under the influence of temperature, the non-magnetically sensitive unit 104 outputs a second output signal, that is, the second output signal is a temperature-dependent signal. This second output signal can be used as a reference signal for temperature drift compensation. It should be noted that the signal types output by each magnetically sensitive unit 103 and the non-magnetically sensitive unit 104 are the same.

[0044] The signal processing circuit 105 can be disposed around the micro-coil 102, such as... Figure 1 and Figure 2As shown, the signal processing circuit 105 includes a microcontroller, which is connected to each magnetic sensing unit 103 and non-magnetic sensing unit 104 via signal transmission lines. The microcontroller is used to perform a weighted summation of the differences between each first output signal and a second output signal to obtain a measured value. In one example, the signal processing circuit 105 performs a weighted summation of the first output signals, and then subtracts the weighted summation result from the second output signal to obtain the measured value. In another example, the signal processing circuit 105 selects one of the multiple first output signals and subtracts it from the second output signal to obtain the measured value. The measured value can be the magnetic field strength.

[0045] The working principle of the above-mentioned temperature drift resistant magnetic sensor is as follows: the magnetic sensing unit 103 senses the magnetic field under the action of an external magnetic field and outputs a first output signal V. 磁 The first output signal V 磁 It is affected by both magnetic field and temperature. The non-magnetically sensitive unit 104 is unaffected by the external magnetic field and only outputs a second output signal V that is related to temperature. 非磁 The signal processing circuit 105 calculates the difference between the two, i.e., V. 测量 =V 磁 -V 非磁 .

[0046] The aforementioned temperature-drift resistant magnetic sensor includes: a substrate 101, a spiral microcoil 102, multiple magnetically sensitive units 103, non-magnetically sensitive units 104, and a signal processing circuit 105. The microcoil 102 is disposed on the substrate 101 to generate a stable magnetic field environment. Each magnetically sensitive unit 103 is located at a different radius of the microcoil 102, and each magnetically sensitive unit 103 outputs a first output signal under the influence of the magnetic field and temperature. The non-magnetically sensitive unit 104 is disposed on the microcoil 102, and the non-magnetically sensitive unit 104 outputs a second output signal under the influence of temperature. The signal processing circuit 105 is connected to both the magnetically sensitive unit 103 and the non-magnetically sensitive unit 104, and outputs a measurement value based on at least one first output signal and one second output signal. This method eliminates temperature drift errors in the obtained measurement value, thereby improving measurement accuracy and reliability.

[0047] Furthermore, a reference signal (i.e., the second output signal) is provided by the non-magnetic sensing unit 104, which is directly compared with the output signal (i.e., the first output signal) of the magnetic sensing unit 103 to achieve temperature drift elimination, without the need for an additional reference magnetic field. Temperature drift compensation is completed directly in the signal, without complex calculations or hysteresis, resulting in strong real-time performance. Moreover, it supports compatibility with GMR, TMR, and AMR, and different types of magnetic sensing units can be configured according to requirements, offering high design flexibility.

[0048] In one embodiment, such as Figure 3The diagram shows a side view of a magnetic sensor resistant to temperature drift. The magnetic sensor also includes an insulating layer 301. The insulating layer 301 is disposed between each magnetic sensing element 103 and the microcoil 102 to prevent contact between the magnetic sensing elements 103 and the microcoil 102, and also provides thermal insulation. The insulating layer 301 is provided to prevent communication between the magnetic sensing elements 103 and the microcoil 102, which could lead to damage to the magnetic sensing elements 103.

[0049] In one embodiment, continue to refer to Figure 3 As shown, the magnetic sensor also includes a magnetic shielding layer 302; the magnetic shielding layer 302 is disposed on the side of the non-magnetically sensitive unit 104 away from the substrate 101, and is used to shield the magnetic field. The magnetic shielding layer 302 is provided to ensure that the non-magnetically sensitive unit 104 is not affected by the magnetic field.

[0050] In one embodiment, the number of coil turns at different radii in the micro-coil 102 increases sequentially from smallest to largest radius. In other words, expanding outward from the center, the number of spiral coil turns gradually increases from the inside out, ensuring the uniformity of the magnetic field of the magnetic sensing unit 103 at different radii.

[0051] In one embodiment, the signal processing circuit 105 is used to perform a weighted summation of the differences between each first output signal and a second output signal, and obtain a measurement value based on the summation result.

[0052] like Figure 4 As shown, the working principle of the temperature drift resistant magnetic sensor is as follows:

[0053] Step 401: Activate microcoil 102 to generate a stable magnetic field working environment.

[0054] Step 402: The first output signal of all magnetic sensing units 103 is acquired by the signal processing circuit 105, and the second output signal of non-magnetic sensing units 104 is acquired by the signal processing circuit 105.

[0055] Step 403: Subtract each first output signal from the second output signal to obtain multiple difference values. Sum these multiple difference values ​​with weights to obtain the measured value.

[0056] In one embodiment, for small-range measurements, the signal processing circuit obtains the measured value based on the difference between a first output signal and a second output signal from the first magnetic sensing unit. For large-range measurements, the signal processing circuit obtains the measured value based on the difference between a first output signal and a second output signal from the second magnetic sensing unit.

[0057] like Figure 5 As shown, the working principle of the temperature drift resistant magnetic sensor is as follows:

[0058] Step 501: Based on the sensor configuration of the magnetic sensor, activate the first magnetic sensing unit, the second magnetic sensing unit, and the signal processing circuit 105.

[0059] Step 502: The signal processing circuit 105 detects whether the current external magnetic field value exceeds the measurement range of the first magnetic sensing unit based on the first output signal of the first magnetic sensing unit and the second magnetic sensing unit.

[0060] Step 503: If the measurement range of the first magnetic sensing unit is exceeded, the first magnetic sensing unit is turned off and the second magnetic sensing unit is turned on. The measured value is obtained based on the difference between the first output signal and the second output signal of the second magnetic sensing unit. If the measurement range of the first magnetic sensing unit is not exceeded, the second magnetic sensing unit is turned off and the first magnetic sensing unit is turned on. The measured value is obtained based on the difference between the first output signal and the second output signal of the first magnetic sensing unit.

[0061] It should be noted that, under the condition of magnetic field change, the magnetic sensor can switch between the first magnetic sensing unit and the second magnetic sensing unit in real time, or switch from using only the first magnetic sensing unit or only the second magnetic sensing unit to a weighted fusion state, that is, switch or fuse the first output signal output by the magnetic sensing unit 103 at different radius positions to achieve dynamic adjustment. This can ensure measurement accuracy and improve the reliability of the magnetic sensor.

[0062] This embodiment combines the outputs of magnetic sensing units 103 at different positions to achieve accurate measurement of magnetic fields from small to large, which means that the magnetic sensor has the characteristic of multi-range measurement.

[0063] The application scenarios of the aforementioned temperature-drift resistant magnetic sensor are as follows: In geomagnetic navigation scenarios, the magnetic sensor provides high-sensitivity measurements through the first magnetic sensing unit, capturing weak geomagnetic changes; when the magnetic sensor approaches a strong magnetic source, the second magnetic sensing unit automatically activates, providing stable measurements over a large magnetic field range. The temperature drift compensation mechanism of the non-magnetic sensing unit 104 ensures measurement accuracy; even under extreme environmental temperature changes, the magnetic sensor can still output accurate measurement values. Of course, the temperature-drift resistant magnetic sensor of this application can also be applied to other fields, such as non-destructive testing and power equipment monitoring.

[0064] In one embodiment, such as Figure 6 As shown, this application provides a flowchart of a magnetic field measurement method, applicable to the magnetic sensor in any of the above-described magnetic sensor embodiments; the method includes:

[0065] Step 601: Multiple magnetic sensing units in the magnetic sensor measure multiple first output signals, each of which is output by the magnetic sensing unit under the influence of magnetic field and temperature.

[0066] Step 602: The non-magnetically sensitive unit in the magnetic sensor measures the second output signal, which is output by the non-magnetically sensitive unit under the influence of temperature.

[0067] Step 603: The signal processing circuit in the magnetic sensor processes at least one first output signal and a second output signal to obtain the measured value.

[0068] The specific implementation method has been described in detail in the above magnetic sensor embodiments, and will not be repeated here.

[0069] In one embodiment, this application also provides a method for fabricating a temperature-drift resistant magnetic sensor, the method comprising the following steps:

[0070] A planar spiral micro-coil 102 is formed on the substrate 101, which can be fabricated by photolithography and metal deposition processes.

[0071] Multiple magnetic sensing elements 103 are deposited above the micro coil 102 according to a predetermined radius. The magnetic sensing element 103 can be of the type of GMR, TMR or AMR.

[0072] A non-magnetically sensitive unit 104 is arranged in the central region of the micro coil 102 and connected to the signal processing circuit 105;

[0073] All magnetic sensing elements 103 are initially calibrated to determine their range and sensitivity.

[0074] The current control parameters of the microcoil 102 were tested and adjusted to optimize the dynamic response capability of the compensation magnetic field.

[0075] In summary, temperature-drift resistant magnetic sensors include:

[0076] Substrate 101 is used to carry micro coil 102 and magnetic sensing unit 103;

[0077] Micro-coil 102 is arranged in a planar spiral on substrate 101 to generate reference magnetic field and compensation magnetic field.

[0078] Multiple magnetic sensing elements 103 are arranged at different radius positions of the micro coil 102 for measuring magnetic field signals of different ranges; the magnetic sensing elements can be of GMR, TMR or AMR type.

[0079] The non-magnetic sensing unit 104 is located in the central region of the micro coil 102. It adopts the same size and technical solution as the magnetic sensing unit 103. A magnetic shielding layer 302 is used on top to ensure that it is not affected by the external magnetic field. It is used to provide a reference signal to correct temperature drift.

[0080] The signal processing circuit 105 is used to receive the first output signal of the magnetic sensing unit 103 and the second output signal of the non-magnetic sensing unit 104, and to realize real-time compensation and correction.

[0081] Multiple magnetic sensing units 103 are arranged sequentially from the inner radius to the outer radius of the micro coil 102, with magnetic sensing units at different radius positions corresponding to different measurement ranges; the magnetic sensing unit 103 at the inner radius is used for measurement in a small magnetic field range, and the magnetic sensing unit 103 at the outer radius is used for measurement in a large magnetic field range.

[0082] The second output signal (i.e., the reference signal) of the non-magnetic sensing unit 104 is compared with the first output signal of the magnetic sensing unit 103 in real time. When the comparison is consistent, the compensation magnetic field is dynamically adjusted by the micro coil 102. The magnitude of the compensation magnetic field is the actual value of the magnetic field to be measured.

[0083] The magnetic field measurement method includes the following steps: generating a reference magnetic field with constant frequency and amplitude through a micro coil 102 and applying it to the region where multiple magnetic sensing units 103 are located;

[0084] Simultaneously, the signal processing circuit 105 acquires the first output signals of multiple magnetic sensing units 103 and compares each first output signal with the second output signal of a non-magnetic sensing unit; based on the magnitude of the first output signal of the magnetic sensing unit 103, the micro coil 102 generates a compensation magnetic field to adjust the changes in the external magnetic field in real time.

[0085] When the first output signal of the magnetic sensing unit 103 matches the second output signal of the non-magnetic sensing unit 104, the induced magnetic field is considered to be zero. The compensation magnetic field generated at this time is the measured value of the external magnetic field. The magnetic sensing unit 103 can be selected as GMR, TMR, or AMR. The appropriate sensing unit type is selected according to the application requirements to meet the measurement requirements. The compensation magnetic field is generated in real time through closed-loop control to eliminate environmental temperature drift and interference signals.

[0086] The measurement process combines the sensitivity of the magnetic sensing unit 103 at different radius positions and calculates a unified and accurate magnetic field value through a weighted summation algorithm.

[0087] When any magnetic sensing unit 103 malfunctions, it is corrected using the first output signal of other magnetic sensing units 103 and the signal of non-magnetic sensing unit 104.

[0088] The number of turns and wire width of the microcoil are optimized according to different measurement ranges to ensure that a uniform and stable reference magnetic field is generated at different radius positions; the microcoil adopts a multi-layer structure to reduce volume and increase magnetic field strength.

[0089] The non-magnetically sensitive unit 104 is disposed in the central region of the micro coil and covered with a magnetic shielding layer to minimize external magnetic field interference.

[0090] The second output signal of the non-magnetic sensitive unit 104 can be digitally filtered to improve the stability of the reference signal.

[0091] The output signal of the magnetic sensing unit 103 is transmitted to the signal processing circuit through an independent channel to avoid coupling between signals of different ranges;

[0092] The signal processing circuit 105 acquires signals from each channel in real time through the analog-to-digital conversion module and adjusts the compensation magnetic field of the micro coil 102 in conjunction with the closed-loop control algorithm.

[0093] The magnetic field measurement process can dynamically select different magnetic sensing units 103 to participate in the measurement to match the range of the magnetic field to be measured. Furthermore, the magnetic sensor can also dynamically optimize the linearity and accuracy of the output signal through a signal fusion algorithm.

[0094] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0095] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0096] It should be noted that, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0097] It is understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0098] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0099] It is understandable that "at least one" refers to one or more, and "multiple" refers to two or more. "At least a part of an element" refers to part or all of an element.

[0100] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0101] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0102] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A temperature drift immune magnetic sensor, characterized by The magnetic sensor includes: substrate; A spiral-shaped microcoil is disposed on the substrate to generate a stable magnetic field environment; Multiple magnetic sensing units are provided, each of which is located at a different radius position of the micro coil. Each magnetic sensing unit outputs a first output signal under the influence of magnetic field and temperature. A non-magnetic sensitive unit is disposed on the micro-coil, and the non-magnetic sensitive unit outputs a second output signal under the influence of temperature; A signal processing circuit, which is connected to each of the magnetic sensing units and the non-magnetic sensing units, is used to output a measurement value based on at least one first output signal and a second output signal; The plurality of magnetic sensing units includes a first magnetic sensing unit and a second magnetic sensing unit; the first magnetic sensing unit is close to the center of the microcoil, and the second magnetic sensing unit is far from the center of the microcoil; In the case of small-range measurement, the signal processing circuit is used to obtain the measured value based on the difference between the first output signal and the second output signal output by the first magnetic sensing unit; in the case of large-range measurement, the signal processing circuit is used to obtain the measured value based on the difference between the first output signal and the second output signal output by the second magnetic sensing unit.

2. The magnetic sensor of claim 1, wherein, The non-magnetically sensitive unit is located in the central region of the micro-coil.

3. The magnetic sensor of claim 1, wherein, The magnetic sensor also includes an insulating layer; The insulating layer is disposed between each of the magnetic sensing units and the microcoil so that the magnetic sensing units do not come into contact with the microcoil and also has a heat insulation function.

4. The magnetic sensor of claim 1, wherein, The magnetic sensor also includes a magnetic shielding layer; The magnetic shielding layer is disposed on the side of the non-magnetically sensitive unit away from the substrate, and is used to shield the magnetic field.

5. The magnetic sensor of claim 1, wherein, The number of coil turns at different radii in the micro-coil increases sequentially from smallest to largest radius.

6. The magnetic sensor of claim 1, wherein, In the weighted fusion state, the signal processing circuit is used to perform a weighted summation of the differences between each of the first output signals and the second output signals, and obtain the measured value based on the summation result.

7. The magnetic sensor according to any one of claims 1 to 6, characterized in that When the magnetic field changes, the magnetic sensor switches between the first magnetic sensing unit and the second magnetic sensing unit, or switches from a state that uses only the first magnetic sensing unit or only the second magnetic sensing unit to a weighted fusion state.

8. The magnetic sensor of claim 1, wherein, The magnetically sensitive unit is GMR, TMR or AMR; the non-magnetically sensitive unit is MTJ.

9. A method of measuring a magnetic field, characterized by, Applied to the magnetic sensor according to any one of claims 1-8; the method includes: The magnetic sensor has multiple magnetic sensing units that measure multiple first output signals, and each first output signal is output by the magnetic sensing unit under the influence of magnetic field and temperature. The non-magnetically sensitive unit in the magnetic sensor measures a second output signal, which is output by the non-magnetically sensitive unit under the influence of temperature. The signal processing circuit in the magnetic sensor processes at least one of the first output signals and the second output signal to obtain a measurement value.

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