Micro-displacement detection device and detection method capable of suppressing external magnetic interference

Abstract

This application relates to a micro-displacement detection device and method capable of suppressing external magnetic interference, belonging to the field of micro-displacement detection technology. The device includes a coil array, a multi-bridge tunnel magnetoresistive junction array, a first magnetoresistive array, and a second magnetoresistive array. Each of the two magnetoresistive arrays has N parallel tunnel magnetoresistive junction bridges. Each tunnel magnetoresistive junction bridge includes one positively correlated tunnel magnetoresistive junction and one negatively correlated tunnel magnetoresistive junction, which are connected in series. The positively correlated and negatively correlated tunnel magnetoresistive junctions in adjacent tunnel magnetoresistive junction bridges are positioned in the same location. The coil array is located between the first and second magnetoresistive arrays, and is arranged parallel to both the first and second magnetoresistive arrays. This application's solution improves the device's resolution, effectively suppresses the influence of external magnetic field interference, and is more suitable for miniaturization.

Description

Technical Field

[0001] This application belongs to the field of micro-displacement detection technology, specifically relating to a redundancy, large range, high-precision displacement detection device and detection method that can suppress external magnetic interference. Background Technology

[0002] Displacement sensors, also known as linear sensors, are sensors that convert displacement into electrical quantities, thereby enabling displacement detection. Common detection methods for displacement sensors include potentiometer-type, inductive-type, magnetic-type, and photoelectric-type sensors. Current technologies convert displacement quantities, which are inconvenient to quantitatively detect and process, into electrical quantities that are easy to quantitatively detect and transmit and process. Classic displacement sensors include resistive, inductive, and capacitive displacement sensors, all of which operate based on electromagnetic principles and physical laws. Among them, potentiometer-type displacement sensors, although simple in structure and easy to use, suffer from friction and wear, resulting in stepped errors, low resolution, and short lifespan. They are also susceptible to temperature and humidity fluctuations, making high-precision detection difficult. Resistance strain gauge displacement sensors offer good linearity, high resolution, simple structure, and ease of use, but suffer from a small displacement measurement range, low measurement accuracy, and poor linearity. Capacitive displacement sensors have advantages such as low power consumption, high impedance, good dynamic characteristics, and non-contact measurement capabilities, but parasitic and distributed capacitance affect measurement accuracy and introduce non-linear errors. Inductive displacement sensors are characterized by simple structure, no friction, high sensitivity, high output power, high measurement accuracy, and wide measurement range, but their sensitivity, linearity, and measurement range are mutually restrictive. Magnetic... Grating displacement sensors have advantages such as simple structure and ease of use, but require shielding and dust protection; laser displacement sensors have the characteristics of strong adaptability, high speed, and high accuracy, and are suitable for detecting the size and positional errors of various rotating bodies and box-shaped parts, but are relatively expensive; grating displacement sensors have high measurement accuracy, large measurement range, high resolution, and strong anti-interference ability, but are expensive, have complex manufacturing processes, poor resistance to shock and vibration, are sensitive to the working environment, and are easily affected by oil and dust; fiber optic displacement sensors have the advantages of long life, high reliability, and high measurement accuracy, but their data processing is complex, and fluctuations in the light source, drift of optoelectronic devices and circuits, bending loss of the fiber itself, changes in the refractive index of the measured object surface, and environmental changes can affect the sensitivity and accuracy of the measurement.

[0003] With further miniaturization, high-precision micro-displacement measurement technology has become an important development direction of modern industrial measurement technology and a research hotspot in the field of measurement. However, due to the influence of size effect, the dynamic performance of micro-displacement detection is seriously affected. When designing the structure, many factors such as the resolution, sensitivity, range, and process accuracy of displacement detection need to be considered. Currently, many technologies cannot meet all these requirements, and there is an urgent need to carry out research on micro-displacement sensors with new effects, new principles, and new structures. Summary of the Invention

[0004] Therefore, this application provides a micro-displacement detection device and detection method that can suppress external magnetic interference, which helps to solve the problems of current micro-displacement detection devices being susceptible to external magnetic field interference, having poor signal detection consistency, and having a large device size.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] In a first aspect, this application provides a micro-displacement detection device capable of suppressing external magnetic interference, comprising:

[0007] Coil array, multi-bridge tunnel magnetoresistive junction array, first magnetoresistive array and second magnetoresistive array;

[0008] Both the first and second magnetoresistive arrays are provided with N parallel tunnel magnetoresistive junction bridges; each tunnel magnetoresistive junction bridge contains one positively correlated tunnel magnetoresistive junction and one negatively correlated tunnel magnetoresistive junction, and the positively correlated tunnel magnetoresistive junction and the negatively correlated tunnel magnetoresistive junction are connected in series; the positively correlated tunnel magnetoresistive junction and the negatively correlated tunnel magnetoresistive junction in two adjacent tunnel magnetoresistive junction bridges are in the same position.

[0009] The coil array is disposed between the first magnetoresistive array and the second magnetoresistive array, and the coil array is arranged parallel to the first magnetoresistive array and the second magnetoresistive array respectively.

[0010] The multi-bridge tunnel magnetoresistive junction array detects the high-rate-of-change magnetic field signal generated by the micro-displacement of the coil array along the sensitive axis direction, and outputs two micro-displacement detection signals.

[0011] Further, the multi-bridge tunnel magnetoresistive junction array includes: a first magnetoresistive substrate, a second magnetoresistive substrate, a third magnetoresistive substrate, a first magnetoresistive circuit array, and a second magnetoresistive circuit array; the first and second magnetoresistive substrates are parallel to each other, and are respectively vertically fixed to both ends of the third magnetoresistive substrate to form a U-shaped structure; the first magnetoresistive circuit array is fixed to the outer wall of the first magnetoresistive substrate, and the second magnetoresistive array is fixed to the inner wall of the first magnetoresistive substrate, with their positions being symmetrical. The second magnetoresistive circuit array is fixed to the outer wall of the second magnetoresistive substrate, and the second magnetoresistive array is fixed to the inner wall of the second magnetoresistive substrate, with their positions being symmetrical. A guide rail is provided on the central axis of the upper plane of the third magnetoresistive substrate, and the coil array is mounted on the guide rail, which can be moved for micro-displacement detection; the first and second magnetoresistive circuit arrays are parallel to each other, and the first and second magnetoresistive arrays are located between the first and second magnetoresistive circuit arrays.

[0012] The first and second magnetoresistive circuit arrays each contain N bridge voltage nodes, N-1 differential voltage output nodes, N-2 differential amplification voltage output nodes, and differential amplification voltage interfaces. Each bridge voltage node is located between the positively correlated tunnel magnetoresistive junction and the negatively correlated tunnel magnetoresistive junction in each tunnel magnetoresistive junction bridge. Each differential voltage output node is located between two adjacent bridge voltage nodes. Each differential amplification voltage output node is located between two adjacent differential voltage output nodes. The differential amplification voltage interface is electrically connected to each of the N-2 differential amplification voltage output nodes.

[0013] Furthermore, the differential amplification voltage interface includes a first differential amplification voltage interface and a second differential amplification voltage interface, and each differential amplification voltage output node is electrically connected to the first differential amplification voltage interface and the second differential amplification voltage interface respectively.

[0014] Furthermore, the coil array specifically includes: a serpentine coil, a magnetic field substrate, and a moving handle; the magnetic field substrate is disposed between the first magnetoresistive array and the second magnetoresistive array; one end of the moving handle is fixedly connected to the magnetic field substrate, and the other end of the moving handle is connected to the sensitive end of the object being measured.

[0015] Furthermore, the serpentine coil specifically includes a first movable serpentine coil and a second movable serpentine coil, which are respectively symmetrically fixed on both sides of the magnetic field substrate.

[0016] Furthermore, the line width 'a' of the serpentine coil ranges from 5 to 80 μm, the line thickness 'h' ranges from 1 to 30 μm, and the line spacing 'D' ranges from 5 to 100 μm.

[0017] Furthermore, both the first and second magnetoresistive arrays include a first tunnel magnetoresistive junction bridge, a second tunnel magnetoresistive junction bridge, a third tunnel magnetoresistive junction bridge, a fourth tunnel magnetoresistive junction bridge, a fifth tunnel magnetoresistive junction bridge, a sixth tunnel magnetoresistive junction bridge, a seventh tunnel magnetoresistive junction bridge, an eighth tunnel magnetoresistive junction bridge, and a ninth tunnel magnetoresistive junction bridge connected in parallel. The first tunnel magnetoresistive junction bridge includes a first positively correlated tunnel magnetoresistive junction and a first negatively correlated tunnel magnetoresistive junction connected in series. The second tunnel magnetoresistive junction bridge includes a second positively correlated tunnel magnetoresistive junction and a second negatively correlated tunnel magnetoresistive junction connected in series. The third tunnel magnetoresistive junction bridge includes a third positively correlated tunnel magnetoresistive junction and a third negatively correlated tunnel magnetoresistive junction connected in series. The fourth tunnel magnetic reluctance junction bridge circuit includes a fourth positively correlated tunnel magnetic reluctance junction and a fourth negatively correlated tunnel magnetic reluctance junction connected in series; the fifth tunnel magnetic reluctance junction bridge circuit includes a fifth positively correlated tunnel magnetic reluctance junction and a fifth negatively correlated tunnel magnetic reluctance junction connected in series; the sixth tunnel magnetic reluctance junction bridge circuit includes a sixth positively correlated tunnel magnetic reluctance junction and a sixth negatively correlated tunnel magnetic reluctance junction connected in series; the seventh tunnel magnetic reluctance junction bridge circuit includes a seventh positively correlated tunnel magnetic reluctance junction and a seventh negatively correlated tunnel magnetic reluctance junction connected in series; the eighth tunnel magnetic reluctance junction bridge circuit includes an eighth positively correlated tunnel magnetic reluctance junction and an eighth negatively correlated tunnel magnetic reluctance junction connected in series; the ninth tunnel magnetic reluctance junction bridge circuit includes a ninth positively correlated tunnel magnetic reluctance junction and a ninth negatively correlated tunnel magnetic reluctance junction connected in series.

[0018] Furthermore, it also includes a serpentine coil power supply, a first magnetoresistive bridge power supply, and a second magnetoresistive bridge power supply; the serpentine coil power supply is electrically connected to the first movable serpentine coil and the second movable serpentine coil respectively; the first magnetoresistive bridge power supply is electrically connected to the first magnetoresistive array; and the second magnetoresistive bridge power supply is electrically connected to the second magnetoresistive array.

[0019] Secondly, this application provides a micro-displacement detection method that can suppress external magnetic interference, including:

[0020] The coil array is set along the sensitive axis of the object being measured, and one end of the coil array is fixed to the object being measured.

[0021] The high-rate-of-change magnetic field signal generated by the micro-displacement of the detection coil array along the sensitive axis direction of the magnetoresistive circuit array is used to obtain the voltage value at the bridge voltage node in each tunnel magnetoresistive bridge circuit.

[0022] The final differential voltage output value is calculated based on the voltage value at the bridge voltage node in each tunnel magnetic reluctance bridge path, combined with the differential output voltage calculation formula.

[0023] Furthermore, the step of calculating the final differential voltage output value based on the voltage value at the bridge voltage node in each tunnel magnetoresistive bridge circuit, combined with the differential output voltage calculation formula, specifically involves: in the N tunnel magnetoresistive bridge circuits, firstly, based on the voltage value at the bridge voltage node in each tunnel magnetoresistive bridge circuit, performing a differential voltage calculation using the differential output voltage calculation formula to obtain the N-1 differential voltage value; then, performing a differential amplification voltage calculation on the N-1 differential voltage value using the differential output voltage calculation formula to obtain the N-2 differential amplification voltage output value, which is the final differential voltage output value.

[0024] Furthermore, the specific formula for calculating the differential output voltage is as follows:

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031] Where: R 11 The output resistance value of the first negatively correlated tunnel magnetoresistive junction; R 12 R is the output resistance value of the first positively correlated tunnel magnetoresistive junction; 21 R is the output resistance value of the second negatively correlated tunnel magnetoresistive junction; 22 R is the output resistance value of the second positively correlated tunnel magnetoresistive junction; 31 R is the output resistance value of the third negatively correlated tunnel magnetoresistive junction; 32 V0 is the output resistance value of the third positively correlated tunnel magnetoresistive junction; V0 is the voltage across the magnetoresistive junction bridge of each bridge path; V0 a V represents the voltage at the junction between the first positively correlated tunnel magnetoresistive junction and the first negatively correlated tunnel magnetoresistive junction. b V represents the voltage at the junction between the second positively correlated tunneling magnetoresistive junction and the second negatively correlated tunneling magnetoresistive junction. cV1 is the voltage value at the junction between the third positively correlated tunnel magnetoresistive junction and the third negatively correlated tunnel magnetoresistive junction; V2 is the differential voltage output value between the second tunnel magnetoresistive junction bridge and the third tunnel magnetoresistive junction bridge; V is the difference between the differential voltage output value between the first tunnel magnetoresistive junction bridge and the second tunnel magnetoresistive junction bridge and the differential voltage output value between the second tunnel magnetoresistive junction bridge and the third tunnel magnetoresistive junction bridge; B0 is the static magnetic field; A is the modulation depth; D is the serpentine coil spacing; d is the magnetoresistive bridge spacing; x is the displacement change; R0 is the initial resistance of the magnetoresistive junction; B1 is the magnetic flux density corresponding to the first tunnel magnetoresistive junction bridge; B2 is the magnetic flux density corresponding to the second tunnel magnetoresistive junction bridge; B3 is the magnetic flux density corresponding to the third tunnel magnetoresistive junction bridge; K is the linear relationship coefficient between the magnetoresistive junction resistance and the magnetic field strength.

[0032] The application employs the above technical solution and has at least the following beneficial effects:

[0033] The micro-displacement detection device for suppressing external magnetic interference provided in this application includes a coil array, a multi-bridge tunnel magnetoresistive junction array, a first magnetoresistive array, and a second magnetoresistive array. Both the first and second magnetoresistive arrays are provided with N parallel tunnel magnetoresistive junction bridges. Each tunnel magnetoresistive junction bridge includes one positively correlated tunnel magnetoresistive junction and one negatively correlated tunnel magnetoresistive junction, which are connected in series. The positively correlated and negatively correlated tunnel magnetoresistive junctions in adjacent tunnel magnetoresistive junction bridges are positioned in the same location. The coil array is positioned between the first and second magnetoresistive arrays, and is parallel to both the first and second magnetoresistive arrays. The multi-bridge tunnel magnetoresistive junction array detects the high-rate-of-change magnetic field signal generated by the micro-displacement of the coil array along the sensitive axis and outputs two micro-displacement detection signals. In this device structure, the present application's solution sets up N parallel tunnel magnetoresistive junction bridges in the first and second magnetoresistive arrays, keeping the positions of each positively correlated magnetoresistive junction and negatively correlated magnetoresistive junction consistent, thereby improving the resolution of the micro-displacement detection device, effectively suppressing the influence of external magnetic field interference, eliminating DC flow without increasing the size of the detection device, and making it more suitable for miniaturization.

[0034] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is an overall structural diagram of the micro-displacement detection device of the present invention;

[0037] Figure 2 This is a diagram of the dual-redundancy high-rate-of-change magnetic field array structure of the present invention;

[0038] Figure 3 This is a structural diagram of the multi-bridge tunnel magnetoresistive array of the present invention;

[0039] Figure 4 These are comparative diagrams of the tunnel magnetic reluctance bridge structure of the present invention;

[0040] Figure 5 Comparison chart of tunnel magnetic reluctance bridge algorithm outputs;

[0041] Figure 6 This is a diagram showing the tunnel magnetic reluctance bridge structure and algorithm output of the present invention;

[0042] Figure 7 This is a circuit diagram of the magnetoresistive junction in the multi-bridge tunnel of the present invention;

[0043] Figure 8 This is a connection diagram of the micro-displacement detection circuit of the present invention;

[0044] In the attached diagram: 1-coil array; 2-first movable serpentine coil; 3-second movable serpentine coil; 4-magnetic field substrate; 5-moving handle; 6-multi-bridge tunnel magnetoresistive junction array; 7-first magnetoresistive array; 8-second magnetoresistive array; 9-first magnetoresistive substrate; 10-second magnetoresistive substrate; 11-third magnetoresistive substrate; 12-guide rail; 13-first positively correlated tunnel magnetoresistive junction; 14-first negatively correlated tunnel magnetoresistive junction; 15-second positively correlated tunnel magnetoresistive junction; 16- 17 - Second negative correlation tunnel magnetic reluctance junction; 18 - Third positive correlation tunnel magnetic reluctance junction; 19 - Fourth positive correlation tunnel magnetic reluctance junction; 20 - Fourth negative correlation tunnel magnetic reluctance junction; 21 - Fifth positive correlation tunnel magnetic reluctance junction; 22 - Fifth negative correlation tunnel magnetic reluctance junction; 23 - Sixth positive correlation tunnel magnetic reluctance junction; 24 - Sixth negative correlation tunnel magnetic reluctance junction; 25 - Seventh positive correlation tunnel magnetic reluctance junction; 26 - Seventh negative correlation tunnel magnetic reluctance junction; 27 - Eighth positive correlation tunnel magnetic reluctance junction; 28 - Tunnel magnetoresistive junction; 29 - Eighth negatively correlated tunnel magnetoresistive junction; 30 - Ninth positively correlated tunnel magnetoresistive junction; 31 - First magnetoresistive circuit array; 32 - Second magnetoresistive circuit array; 33 - First group of bridge voltage nodes; 34 - Second group of bridge voltage nodes; 35 - Third group of bridge voltage nodes; 36 - Fourth group of bridge voltage nodes; 37 - Fifth group of bridge voltage nodes; 38 - Sixth group of bridge voltage nodes; 39 - Seventh group of bridge voltage nodes; 40 - Eighth group of bridge voltage nodes; 41 - Ninth group of bridge voltage nodes; 42 - First differential amplification voltage interface of the first magnetoresistive array; 43 - Second differential amplification voltage interface of the first magnetoresistive array; 44 - First serpentine coil power supply; 45 - First magnetoresistive bridge power supply; 46 - First differential amplification voltage interface of the second magnetoresistive array; 47 - Second differential amplification voltage interface of the second magnetoresistive array; 48 - Second serpentine coil power supply; 49 - Second magnetoresistive bridge power supply. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0046] Please see Figure 1 , Figure 1 This is an overall structural diagram of a micro-displacement detection device capable of suppressing external magnetic interference, illustrated according to an exemplary embodiment. Figure 1 As shown, the device includes: a coil array 1, a multi-bridge tunnel magnetoresistive junction array 6, a first magnetoresistive array 7, and a second magnetoresistive array 8. Among them,

[0047] Both the first magnetoresistive array 7 and the second magnetoresistive array 8 are provided with N (N≥3) parallel tunnel magnetoresistive junction bridges; each tunnel magnetoresistive junction bridge contains one positively correlated tunnel magnetoresistive junction and one negatively correlated tunnel magnetoresistive junction, and the positively correlated tunnel magnetoresistive junction and the negatively correlated tunnel magnetoresistive junction are connected in series; the positively correlated tunnel magnetoresistive junction and the negatively correlated tunnel magnetoresistive junction in two adjacent tunnel magnetoresistive junction bridges are in the same position.

[0048] The coil array 1 is positioned between the first magnetoresistive array 7 and the second magnetoresistive array 8, and is arranged parallel to both the first magnetoresistive array 7 and the second magnetoresistive array 8. When energized, the coil array 1 generates a high-rate-of-change magnetic field; therefore, the coil array 1 is essentially a high-rate-of-change magnetic field array.

[0049] The multi-bridge tunnel magnetoresistive array 6 detects the high rate of change magnetic field signal generated by the micro-displacement of the coil array 1 along the sensitive axis direction, and outputs two micro-displacement detection signals.

[0050] Reference Figure 2 As shown, the coil array 1 designed in this invention specifically includes: a serpentine coil, a magnetic field substrate 4, and a moving handle 5; the magnetic field substrate 4 is disposed between the first magnetoresistive array 7 and the second magnetoresistive array 8; one end of the moving handle 5 is fixedly connected to the magnetic field substrate 4, and the other end of the moving handle 5 is connected to the sensitive end of the object being measured, and the moving handle 5 drives the magnetic field substrate 4 to change a small displacement according to the sensitive end of the object being measured.

[0051] The serpentine coil specifically includes a first movable serpentine coil 2 and a second movable serpentine coil 3. The first movable serpentine coil 2 and the second movable serpentine coil 3 are symmetrically bonded and fixed to both sides of the magnetic field substrate 4, achieving a dual-redundancy, high-rate-of-change magnetic field design. The rate of change and linear period of the magnetic field can be controlled by designing and changing the linewidth a, line thickness h, and line spacing D of the serpentine coils. The linewidth a ranges from 5 to 80 μm, the line thickness h ranges from 1 to 30 μm, and the line spacing D ranges from 5 to 100 μm. Different linewidths a, line thickness h, and line spacing D are selected according to resolution, range, and period requirements. The system is composed of multiple periodic serpentine coil regions, resulting in a very large range. It is important to note that when the detected displacement change range is within a certain orientation, the differential voltage output circuit design in the magnetoresistive circuit can be adjusted to achieve redundant signal detection.

[0052] Reference Figure 3As shown, the multi-bridge tunnel magnetoresistive junction array 6 designed in this invention includes: a first magnetoresistive substrate 9, a second magnetoresistive substrate 10, a third magnetoresistive substrate 11, a first magnetoresistive circuit array 31, and a second magnetoresistive circuit array 32. The first magnetoresistive substrate 9 and the second magnetoresistive substrate 10 are parallel to each other, and the first magnetoresistive substrate 9 and the second magnetoresistive substrate 10 are respectively vertically fixed to both ends of the third magnetoresistive substrate 11 to form a U-shaped structure. Among them, the first magnetoresistive circuit array 31 is fixed to the outer wall of the first magnetoresistive substrate 9, and the first magnetoresistive array 7 is fixed to the inner wall of the first magnetoresistive substrate 9; the second magnetoresistive circuit array 32 is fixed to the outer wall of the second magnetoresistive substrate 10, and the second magnetoresistive array 8 is fixed to the inner wall of the second magnetoresistive substrate 10; a guide rail 12 is provided on the central axis of the upper plane of the third magnetoresistive substrate 11, and the coil array 1 is mounted on the guide rail 12; the first magnetoresistive circuit array 31 and the second magnetoresistive circuit array 32 are parallel to each other, and the first magnetoresistive array 7 and the second magnetoresistive array 8 are disposed between the first magnetoresistive circuit array 31 and the second magnetoresistive circuit array 32.

[0053] Furthermore, both the first magnetoresistive circuit array 31 and the second magnetoresistive circuit array 32 include N bridge voltage nodes, N-1 differential voltage output nodes, N-2 differential amplification voltage output nodes, and differential amplification voltage interfaces. Each bridge voltage node is located between the positively correlated tunnel magnetoresistive junction and the negatively correlated tunnel magnetoresistive junction in each tunnel magnetoresistive junction bridge. Each differential voltage output node is located between two adjacent bridge voltage nodes. Each differential amplification voltage output node is located between two adjacent differential voltage output nodes. The differential amplification voltage interface includes a first differential amplification voltage interface and a second differential amplification voltage interface, and each differential amplification voltage output node is electrically connected to the first differential amplification voltage interface and the second differential amplification voltage interface, respectively.

[0054] Specifically, Figure 3 In this embodiment, the second magnetoresistive circuit array 32 includes a first group of bridge voltage nodes 33, a second group of bridge voltage nodes 34, a third group of bridge voltage nodes 35, a fourth group of bridge voltage nodes 36, a fifth group of bridge voltage nodes 37, a sixth group of bridge voltage nodes 38, a seventh group of bridge voltage nodes 39, an eighth group of bridge voltage nodes 40, a ninth group of bridge voltage nodes 41, a first differential amplification voltage interface 46 of the second magnetoresistive array, a second differential amplification voltage interface 47 of the second magnetoresistive array, a second serpentine coil power supply 48, and a second magnetoresistive bridge power supply 49. Since the bridge voltage nodes of the second magnetoresistive circuit array 32, the first differential amplification voltage interface 42 of the first magnetoresistive array, the second differential amplification voltage interface 43 of the first magnetoresistive array, the first serpentine coil power supply 44, and the first magnetoresistive bridge power supply 45 of the first magnetoresistive circuit array 32 are all the same as those of the first magnetoresistive circuit array 31, and all have the same circuit structure and layout, the structure and layout of the first magnetoresistive circuit array 31 will not be described again here.

[0055] Furthermore, the first magnetoresistive circuit array 31 and the second magnetoresistive circuit array 32 designed in this invention respectively include N bridge voltage output signals, 2 total output signals, and 2 power supply modules. The output signals of the N bridge voltage nodes are differentially output once through N-1 differential voltage output nodes to obtain N-1 differential voltage signals. Then, the differential voltage signals of the N-1 differential voltage output nodes are differentially output a second time through N-2 differential amplification voltage output nodes to obtain N-2 differential amplification signals. The N-2 differential amplification voltage output signals can be designed in series or parallel as needed, and the final differential voltage signal can be output through the 2 total output signal interface. The first magnetoresistive circuit array 31 and the second magnetoresistive circuit array 32 are arranged parallel to and opposite to the first movable serpentine coil 2 and the second movable serpentine coil 3, respectively. The nine bridge voltage nodes, the second serpentine coil power supply 48, the second magnetoresistive bridge power supply 49, and the 2 total output signal interface are disposed on the second magnetoresistive substrate 10 and firmly bonded thereto. In the multi-bridge tunnel magnetoresistive arrays 7 and 8, there is a magnetoresistive differential voltage between two adjacent paths, and a differential amplified voltage output signal between two adjacent magnetoresistive differential voltages in the first magnetoresistive array 7 and the second magnetoresistive array 8; the two differential amplified voltage interfaces of the second magnetoresistive array 8 are the final differential voltage output interfaces for the two circuit settings.

[0056] like Figure 4 , 5 The diagram shows a comparison of the tunnel magnetoresistive junction bridge structure and algorithm output. The first tunnel magnetoresistive junction bridge includes a first positively correlated tunnel magnetoresistive junction 13 and a first negatively correlated tunnel magnetoresistive junction 14; the second tunnel magnetoresistive junction bridge includes a second positively correlated tunnel magnetoresistive junction 15 and a second negatively correlated tunnel magnetoresistive junction 16; the output resistance value of the first positively correlated tunnel magnetoresistive junction 13 is R. 12 The output resistance value of the first negatively correlated tunnel magnetoresistive junction 14 is R. 11 The output resistance value of the second positively correlated tunnel magnetoresistive junction 15 is R. 22 The output resistance value of the second negatively correlated tunnel magnetoresistive junction 16 is R. 21 The voltage across each bridge tunnel magnetoresistive junction is V0; the voltage at the junction between the first positively correlated tunnel magnetoresistive junction 13 and the first negatively correlated tunnel magnetoresistive junction 14 is V. a The voltage at the junction between the second positively correlated tunnel magnetoresistive junction 15 and the second negatively correlated tunnel magnetoresistive junction 16 is V. b Simulation results of the energized magnetic field detection using the serpentine coil show that its magnetic induction intensity curve is consistent with the cosine function curve. The output resistance value of the tunnel magnetoresistive junction can be expressed as: R 11 =R0-K·B1,R 12 =R0+K·B1、R21 =R0-K·B2、R 22 =R0+K·B2.

[0057] The existing differential output voltage method is as follows:

[0058]

[0059]

[0060]

[0061] The differential output voltage method provided by this invention is as follows:

[0062]

[0063]

[0064]

[0065] Where: B0 is the static magnetic field, A is the modulation depth, D is the serpentine coil spacing, d is the magnetoresistive bridge spacing; x is the displacement change; R0 is the initial resistance of the magnetoresistive junction; B1 is the magnetic induction intensity corresponding to the first tunnel magnetoresistive junction bridge; B2 is the magnetic induction intensity corresponding to the second tunnel magnetoresistive junction bridge; K is the linear relationship coefficient between the magnetoresistive junction resistance and the magnetic field strength.

[0066] Figure 5 The output voltage curve of the prior art solution shown in the attached figure (a) includes a DC quantity, while Figure 5 (b) The output voltage curve of the present invention shown in the partial figures does not contain DC, which can be directly eliminated when the micro-displacement detection signal is output. The output voltage of the present invention does not require a rectifier module or other means to eliminate DC, which can greatly reduce the size of the micro-displacement detection device and make it more suitable for miniaturization. By integrating and differentiating the output voltage of the present invention, with the serpentine coil spacing D fixed, the output voltage of the present invention can reach its maximum value when d = D / 2.

[0067] like Figure 6 The diagram shown illustrates the tunnel magnetoresistive junction bridge structure and algorithm output of this invention. The tunnel magnetoresistive junction bridge structure of this invention is based on existing technical solutions with further differential processing. The output resistance value of the tunnel magnetoresistive junction in the third tunnel magnetoresistive junction bridge can be expressed as: R 31 =R0-K·B3、R 32 =R0 + K·B3. The differential output voltage method of this invention is as follows:

[0068]

[0069]

[0070]

[0071]

[0072]

[0073]

[0074] Figure 6 The output voltage curve of the present invention shown does not contain DC, and therefore does not require a rectifier module or other means to eliminate DC. DC can be directly eliminated when the micro-displacement detection signal is output, which can greatly reduce the size of the micro-displacement detection device and make it more suitable for miniaturization. The output voltage of the present invention is amplified based on the original invention, making weak micro-displacement signals easier to detect.

[0075] Reference Figure 7 As shown, both the first magnetoresistive array 7 and the second magnetoresistive array 8 include a first tunnel magnetoresistive junction bridge circuit, a second tunnel magnetoresistive junction bridge circuit, a third tunnel magnetoresistive junction bridge circuit, a fourth tunnel magnetoresistive junction bridge circuit, a fifth tunnel magnetoresistive junction bridge circuit, a sixth tunnel magnetoresistive junction bridge circuit, a seventh tunnel magnetoresistive junction bridge circuit, an eighth tunnel magnetoresistive junction bridge circuit, and a ninth tunnel magnetoresistive junction bridge circuit connected in parallel. The first tunnel magnetoresistive junction bridge circuit includes a first positively correlated tunnel magnetoresistive junction 13 and a first negatively correlated tunnel magnetoresistive junction 14 connected in series. The second tunnel magnetoresistive junction bridge circuit includes a second positively correlated tunnel magnetoresistive junction 15 and a second negatively correlated tunnel magnetoresistive junction 16 connected in series. The third tunnel magnetoresistive junction bridge circuit includes a third positively correlated tunnel magnetoresistive junction 17 and a third negatively correlated tunnel magnetoresistive junction 18 connected in series. The fourth... The tunnel magnetic reluctance junction bridge circuit includes a fourth positively correlated tunnel magnetic reluctance junction 19 and a fourth negatively correlated tunnel magnetic reluctance junction 20 connected in series; the fifth tunnel magnetic reluctance junction bridge circuit includes a fifth positively correlated tunnel magnetic reluctance junction 21 and a fifth negatively correlated tunnel magnetic reluctance junction 22 connected in series; the sixth tunnel magnetic reluctance junction bridge circuit includes a sixth positively correlated tunnel magnetic reluctance junction 23 and a sixth negatively correlated tunnel magnetic reluctance junction 24 connected in series; the seventh tunnel magnetic reluctance junction bridge circuit includes a seventh positively correlated tunnel magnetic reluctance junction 25 and a seventh negatively correlated tunnel magnetic reluctance junction 26 connected in series; the eighth tunnel magnetic reluctance junction bridge circuit includes an eighth positively correlated tunnel magnetic reluctance junction 27 and an eighth negatively correlated tunnel magnetic reluctance junction 28 connected in series; and the ninth tunnel magnetic reluctance junction bridge circuit includes a ninth positively correlated tunnel magnetic reluctance junction 29 and a ninth negatively correlated tunnel magnetic reluctance junction 30 connected in series.

[0076] In this multi-bridge tunnel magnetoresistive junction circuit, each path contains one positively correlated tunnel magnetoresistive junction and one negatively correlated tunnel magnetoresistive junction. The tunnel magnetoresistive junction regions of each bridge are connected in parallel. As needed, N (N≥3) identical tunnel magnetoresistive junction bridges can be connected in parallel, but the positions of the positively correlated and negatively correlated tunnel magnetoresistive junctions in adjacent bridges remain consistent. The voltage between the positively correlated and negatively correlated tunnel magnetoresistive junctions in any bridge is defined by the following group of bridge voltages: Group 1, Group 2, Group 3, Group 4, Group 5, Group 6, Group 7, Group 8, and Group 9. The differential voltage signals output from any two adjacent bridges in the multi-bridge tunnel magnetoresistive junction circuit are the following groups of magnetoresistive differential voltages: V1 (first group), V2 (second group), V3 (third group), V4 (fourth group), V5 (fifth group), V6 (sixth group), V7 (seventh group), and V8 (eighth group). The differentially amplified voltage signals output from any two adjacent differential voltage signals are the following groups of differentially amplified voltages: U1 (first group), U2 (second group), U3 (third group), U4 (fourth group), U5 (fifth group), U6 (sixth group), and U7 (seventh group).

[0077] like Figure 8 As shown, the present invention provides a schematic diagram of the connection of a micro-displacement detection circuit. The first magnetoresistive circuit array 31 and the second magnetoresistive circuit array 32 respectively include N-1 differential voltage output signals, 2 total output signals, and 2 power supply modules (serpentine coil power supply and magnetoresistive bridge power supply). The N-1 differential voltage output signals are V1, V2, V3, V4, V5, V6, V7, and V8. The N-1 differential voltage output signals are subjected to secondary differential output to produce N-2 differential amplified signals. The N-2 differential amplified voltage output signals can be designed in series, parallel, or other circuit configurations as required and can be output through the 2 total output signal interface. When the first serpentine coil power supply 44 and the second serpentine coil power supply 48 in the first magnetoresistive circuit array 31 and the second magnetoresistive circuit array 32 energize the first movable serpentine coil 2 and the second movable serpentine coil 3, and the first magnetoresistive bridge power supply 45 and the second magnetoresistive bridge power supply 49 energize the N tunnel magnetoresistive junction bridges, and the first movable serpentine coil 2 and the second movable serpentine coil 3 undergo a micro-displacement change relative to the first magnetoresistive array 7 and the second magnetoresistive array 8, the first differential amplification voltage interface and the second differential amplification voltage interface of the first magnetoresistive array 7 and the second differential amplification voltage interface of the second magnetoresistive array 8 respectively output detection signals, realizing at least dual-redundancy micro-displacement signal measurement.

[0078] Furthermore, the power supply in this application includes a first serpentine coil power supply 44, a second serpentine coil power supply 48, a first magnetoresistive bridge power supply 45, and a second magnetoresistive bridge power supply 49. The first serpentine coil power supply 44 and the second serpentine coil power supply 48 can be combined to power a single serpentine coil power supply, further reducing the size of the device.

[0079] In this application, when the object under test is displaced, the moving handle 5 drives two sets of movable serpentine coils set on the magnetic field substrate 4 to move together along the sensitive direction. The two sets of movable serpentine coils undergo a small displacement relative to the multi-bridge tunnel magnetoresistive array. The movable serpentine coils generate a periodic high-rate-of-change magnetic field. The positive and negative correlated tunnel magnetoresistive junctions in the multi-bridge tunnel magnetoresistive array are sensitive to the magnetic field changes caused by the small displacement. The magnetic field changes cause a change in the probability of spin electron tunneling in the magnetoresistive junction, resulting in a tunnel magnetoresistive effect, which leads to a drastic change in the resistance of the magnetoresistive junction. Each channel in the multi-bridge tunnel magnetoresistive array can be sensitive to the magnetic field signal. By differentially outputting the bridges of adjacent channels, the DC influence of external interference magnetic fields can be suppressed. The differential voltage values ​​of the two channels are further differentially divided to achieve a further amplification of the detection signal. By measuring the secondary differential voltage, the micro-displacement detection in the sensitive axis direction can be achieved.

[0080] The magnetoresistive circuit in this application consists of positively correlated tunnel magnetoresistive junctions (TMJs) and negatively correlated TMMs connected in series and then in parallel to achieve differential voltage detection. Adjacent differential voltages are further divided to produce differential voltage outputs. The differential outputs of the three-channel TMM bridge circuit effectively amplify the displacement detection signal. The multiple TMM bridge circuits provide redundant three-channel differential voltage outputs. A dual-redundant high-rate-of-change magnetic field, via a guide rail, enables relative micro-displacement detection with the multi-bridge TMM array, achieving high-precision, large-range dual-redundant micro-displacement detection. Compared to existing micrometer-level displacement detection devices, this invention features a controllable high-rate-of-change magnetic field period, increasing the detection range. The design of a dual-sided magnetic field allows for dual-redundant detection. The differential voltage detection using positive and negative magnetoresistive structures effectively suppresses external magnetic interference and eliminates DC current. The three-channel differential output amplifies the signal, and the multiple channels provide redundant signal outputs, improving the accuracy of micro-displacement detection. This device has a reasonable and simple structural design, eliminates the need for rectifier modules to eliminate DC current, and is more suitable for miniaturization, making it more practical.

[0081] Furthermore, this application provides a micro-displacement detection method capable of suppressing external magnetic interference, applied to the micro-displacement detection device capable of suppressing external magnetic interference provided in this application. The method includes the following steps:

[0082] The coil array 1 is set along the sensitive axis of the object being measured, and one end of the coil array 1 is fixed to the object being measured.

[0083] The high-rate-of-change magnetic field signal generated by the micro-displacement of the magnetoresistive circuit array 1 along the sensitive axis direction is used to obtain the voltage value at the bridge voltage node in each tunnel magnetoresistive bridge circuit.

[0084] The final differential voltage output value is calculated based on the voltage value at the bridge voltage node in each tunnel magnetic reluctance bridge path, combined with the differential output voltage calculation formula.

[0085] Furthermore, the step of calculating the final differential voltage output value based on the voltage value at the bridge voltage node in each tunnel magnetoresistive bridge circuit, combined with the differential output voltage calculation formula, specifically involves: in the N tunnel magnetoresistive bridge circuits, firstly, based on the voltage value at the bridge voltage node in each tunnel magnetoresistive bridge circuit, performing a differential voltage calculation using the differential output voltage calculation formula to obtain the N-1 differential voltage value; then, performing a differential amplification voltage calculation on the N-1 differential voltage value using the differential output voltage calculation formula to obtain the N-2 differential amplification voltage output value, which is the final differential voltage output value.

[0086] Furthermore, in one embodiment, the formula for calculating the differential output voltage is as follows:

[0087]

[0088]

[0089]

[0090]

[0091]

[0092]

[0093] Where: R 11 The output resistance value of the first negatively correlated tunnel magnetoresistive junction 14; R 12 R is the output resistance value of the first positively correlated tunnel magnetoresistive junction 13; 21 The output resistance value of the second negatively correlated tunnel magnetoresistive junction 16; R 22 R is the output resistance value of the second positively correlated tunnel magnetoresistive junction 15; 31 The output resistance value of the third negatively correlated tunnel magnetoresistive junction 18; R 32 V0 is the output resistance value of the third positively correlated tunnel magnetoresistive junction 17; V0 is the voltage across the magnetoresistive junction bridge of each bridge path; V0 a V is the voltage value at the junction between the first positively correlated tunnel magnetoresistive junction 13 and the first negatively correlated tunnel magnetoresistive junction 14; b V is the voltage value at the junction between the second positively correlated tunnel magnetoresistive junction 15 and the second negatively correlated tunnel magnetoresistive junction 16;c V1 is the voltage value at the junction between the third positively correlated tunnel magnetoresistive junction 17 and the third negatively correlated tunnel magnetoresistive junction 18; V2 is the differential voltage output value between the first tunnel magnetoresistive junction bridge circuit and the second tunnel magnetoresistive junction bridge circuit; V is the differential voltage output value between the second tunnel magnetoresistive junction bridge circuit and the third tunnel magnetoresistive junction bridge circuit; V is the difference between the differential voltage output value between the first tunnel magnetoresistive junction bridge circuit and the second tunnel magnetoresistive junction bridge circuit and the differential voltage output value between the second tunnel magnetoresistive junction bridge circuit and the third tunnel magnetoresistive junction bridge circuit; B0 is the static magnetic field; A is the modulation depth; D is the serpentine coil spacing; d is the magnetoresistive bridge circuit spacing; x is the displacement change; R0 is the initial resistance of the magnetoresistive junction; B1 is the magnetic induction intensity corresponding to the first tunnel magnetoresistive junction bridge circuit; B2 is the magnetic induction intensity corresponding to the second tunnel magnetoresistive junction bridge circuit; B3 is the magnetic induction intensity corresponding to the third tunnel magnetoresistive junction bridge circuit; K is the linear relationship coefficient between the magnetoresistive junction resistance and the magnetic field strength.

[0094] It should be noted that in the description of this application, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this application, unless otherwise stated, "multiple" or "more" means at least two.

[0095] It should be understood that when an element is referred to as “fixed to” or “set on” another element, it may be directly on the other element or may be interposed with an intervening element; when an element is referred to as “connected to” another element, it may be directly connected to the other element or may be interposed with an intervening element. Furthermore, the term “connected” as used herein may include wireless connections; the word “and / or” as used includes any and all combinations of one or more of the associated listed items.

[0096] Any process or method description in the flowchart or otherwise herein can be understood as: representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the function involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0097] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0098] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0099] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0100] The storage media mentioned above can be read-only memory, disk, or optical disk, etc.

[0101] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0102] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A micro-displacement detection device capable of suppressing external magnetic interference, characterized in that, include: Coil array, multi-bridge tunnel magnetoresistive junction array, first magnetoresistive array and second magnetoresistive array; Both the first and second magnetoresistive arrays are provided with N parallel tunnel magnetoresistive junction bridges; each tunnel magnetoresistive junction bridge contains one positively correlated tunnel magnetoresistive junction and one negatively correlated tunnel magnetoresistive junction, and the positively correlated tunnel magnetoresistive junction and the negatively correlated tunnel magnetoresistive junction are connected in series; the positively correlated tunnel magnetoresistive junction and the negatively correlated tunnel magnetoresistive junction in two adjacent tunnel magnetoresistive junction bridges are in the same position. The coil array is disposed between the first magnetoresistive array and the second magnetoresistive array, and the coil array is arranged parallel to the first magnetoresistive array and the second magnetoresistive array respectively. The multi-bridge tunnel magnetoresistive junction array detects the high-rate-of-change magnetic field signal generated by the micro-displacement of the coil array along the sensitive axis direction, and outputs two micro-displacement detection signals. Both the first and second magnetoresistive circuit arrays include N bridge voltage nodes, N-1 differential voltage output nodes, N-2 differential amplification voltage output nodes, and differential amplification voltage interfaces; each bridge voltage node is located between the positively correlated tunnel magnetoresistive junction and the negatively correlated tunnel magnetoresistive junction in each tunnel magnetoresistive junction bridge; each differential voltage output node is located between two adjacent bridge voltage nodes; each differential amplification voltage output node is located between two adjacent differential voltage output nodes. The differential amplifier voltage interface is electrically connected to N-2 differential amplifier voltage output nodes respectively; The multi-bridge tunnel magnetoresistive junction array includes: a first magnetoresistive substrate, a second magnetoresistive substrate, a third magnetoresistive substrate, a first magnetoresistive circuit array, and a second magnetoresistive circuit array; the first magnetoresistive substrate and the second magnetoresistive substrate are parallel to each other, and the first magnetoresistive substrate and the second magnetoresistive substrate are respectively vertically fixed to the two ends of the third magnetoresistive substrate to form a U-shaped structure; the first magnetoresistive circuit array is fixed to the outer wall of the first magnetoresistive substrate and the second magnetoresistive circuit array is fixed to the inner wall of the first magnetoresistive substrate; the second magnetoresistive circuit array is fixed to the outer wall of the second magnetoresistive substrate and the second magnetoresistive circuit array is fixed to the inner wall of the second magnetoresistive substrate; a guide rail is provided on the central axis of the upper plane of the third magnetoresistive substrate, and the coil array is mounted on the guide rail; the first magnetoresistive circuit array and the second magnetoresistive circuit array are parallel to each other, and the first magnetoresistive array and the second magnetoresistive circuit array are located between the first magnetoresistive circuit array and the second magnetoresistive circuit array; The differential amplified voltage interface includes a first differential amplified voltage interface and a second differential amplified voltage interface, and each differential amplified voltage output node is electrically connected to the first differential amplified voltage interface and the second differential amplified voltage interface respectively. The coil array specifically includes: a serpentine coil, a magnetic field substrate, and a moving handle; the magnetic field substrate is disposed between the first magnetoresistive array and the second magnetoresistive array; one end of the moving handle is fixedly connected to the magnetic field substrate, and the other end of the moving handle is connected to the sensitive end of the object being measured. The serpentine coil specifically includes a first movable serpentine coil and a second movable serpentine coil, which are symmetrically fixed on both sides of the magnetic field substrate.

2. The micro-displacement detection device capable of suppressing external magnetic interference according to claim 1, characterized in that, The serpentine coil has a line width a ranging from 5 to 80 μm, a line thickness h ranging from 1 to 30 μm, and a line spacing D ranging from 5 to 100 μm.

3. The micro-displacement detection device capable of suppressing external magnetic interference according to claim 1, characterized in that, Both the first and second magnetoresistive arrays include parallel-connected first, second, third, fourth, fifth, sixth, seventh, eighth, and ninth tunnel magnetoresistive junction bridges. The first tunnel magnetoresistive junction bridge includes a first positively correlated tunnel magnetoresistive junction and a first negatively correlated tunnel magnetoresistive junction connected in series. The second tunnel magnetoresistive junction bridge includes a second positively correlated tunnel magnetoresistive junction and a second negatively correlated tunnel magnetoresistive junction connected in series. The third tunnel magnetoresistive junction bridge includes a third positively correlated tunnel magnetoresistive junction and a third negatively correlated tunnel magnetoresistive junction connected in series. The fourth tunnel magnetic reluctance junction bridge circuit includes a fourth positively correlated tunnel magnetic reluctance junction and a fourth negatively correlated tunnel magnetic reluctance junction connected in series; the fifth tunnel magnetic reluctance junction bridge circuit includes a fifth positively correlated tunnel magnetic reluctance junction and a fifth negatively correlated tunnel magnetic reluctance junction connected in series; the sixth tunnel magnetic reluctance junction bridge circuit includes a sixth positively correlated tunnel magnetic reluctance junction and a sixth negatively correlated tunnel magnetic reluctance junction connected in series; the seventh tunnel magnetic reluctance junction bridge circuit includes a seventh positively correlated tunnel magnetic reluctance junction and a seventh negatively correlated tunnel magnetic reluctance junction connected in series; the eighth tunnel magnetic reluctance junction bridge circuit includes an eighth positively correlated tunnel magnetic reluctance junction and an eighth negatively correlated tunnel magnetic reluctance junction connected in series; the ninth tunnel magnetic reluctance junction bridge circuit includes a ninth positively correlated tunnel magnetic reluctance junction and a ninth negatively correlated tunnel magnetic reluctance junction connected in series.

4. The micro-displacement detection device capable of suppressing external magnetic interference according to claim 1, characterized in that, It also includes a serpentine coil power supply, a first magnetoresistive bridge power supply, and a second magnetoresistive bridge power supply; the serpentine coil power supply is electrically connected to the first movable serpentine coil and the second movable serpentine coil respectively; the first magnetoresistive bridge power supply is electrically connected to the first magnetoresistive array; and the second magnetoresistive bridge power supply is electrically connected to the second magnetoresistive array.

5. A micro-displacement detection method capable of suppressing external magnetic interference, characterized in that, The micro-displacement detection device capable of suppressing external magnetic interference as described in any one of claims 1 to 4 comprises: The coil array is set along the sensitive axis of the object being measured, and one end of the coil array is fixed to the object being measured. The high-rate-of-change magnetic field signal generated by the micro-displacement of the detection coil array along the sensitive axis direction of the magnetoresistive circuit array is used to obtain the voltage value at the bridge voltage node in each tunnel magnetoresistive bridge circuit. The final differential voltage output value is calculated based on the voltage value at the bridge voltage node in each tunnel magnetic reluctance bridge path, combined with the differential output voltage calculation formula.

6. The micro-displacement detection method capable of suppressing external magnetic interference according to claim 5, characterized in that, The specific steps for calculating the final differential voltage output value based on the voltage value at the bridge voltage node in each tunnel magnetoresistive bridge circuit and the differential output voltage calculation formula are as follows: In N tunnel magnetoresistive bridge circuits, firstly, based on the voltage value at the bridge voltage node in each tunnel magnetoresistive bridge circuit, perform a differential voltage calculation using the differential output voltage calculation formula to obtain N-1 differential voltage values. Then, the differential output voltage calculation formula is used to perform a differential amplification voltage calculation on the N-1 differential voltage value to obtain the N-2 differential amplification voltage output value, which is the final differential voltage output value.

7. The micro-displacement detection method capable of suppressing external magnetic interference according to claim 5, characterized in that, The specific formula for calculating the differential output voltage is as follows: ； ； ； ； ； Where: R 11 The output resistance value of the first negatively correlated tunnel magnetoresistive junction; R 12 R is the output resistance value of the first positively correlated tunnel magnetoresistive junction; 21 R is the output resistance value of the second negatively correlated tunnel magnetoresistive junction; 22 R is the output resistance value of the second positively correlated tunnel magnetoresistive junction; 31 R is the output resistance value of the third negatively correlated tunnel magnetoresistive junction; 32 V0 is the output resistance value of the third positively correlated tunnel magnetoresistive junction; V0 is the voltage across the magnetoresistive junction bridge of each bridge path; V0 a V represents the voltage at the junction between the first positively correlated tunnel magnetoresistive junction and the first negatively correlated tunnel magnetoresistive junction. b V represents the voltage at the junction between the second positively correlated tunneling magnetoresistive junction and the second negatively correlated tunneling magnetoresistive junction. c V1 is the voltage value at the junction between the third positively correlated tunnel magnetoresistive junction and the third negatively correlated tunnel magnetoresistive junction; V2 is the differential voltage output value between the second tunnel magnetoresistive junction bridge and the third tunnel magnetoresistive junction bridge; V is the difference between the differential voltage output value between the first tunnel magnetoresistive junction bridge and the second tunnel magnetoresistive junction bridge and the differential voltage output value between the second tunnel magnetoresistive junction bridge and the third tunnel magnetoresistive junction bridge; B0 is the static magnetic field; A is the modulation depth; D is the serpentine coil spacing; d is the magnetoresistive bridge spacing; x is the displacement change; R0 is the initial resistance of the magnetoresistive junction; B1 is the magnetic flux density corresponding to the first tunnel magnetoresistive junction bridge; B2 is the magnetic flux density corresponding to the second tunnel magnetoresistive junction bridge; B3 is the magnetic flux density corresponding to the third tunnel magnetoresistive junction bridge; K is the linear relationship coefficient between the magnetoresistive junction resistance and the magnetic field strength.

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