A high-sensitivity angle detection device based on tunneling magnetoresistance effect

Abstract

This invention belongs to the technical field of angle detection devices, specifically relating to a high-sensitivity angle detection device based on the tunneling magnetoresistive effect. It includes an upper substrate and a lower substrate, with the upper substrate positioned above the lower substrate and parallel to it, without contact between them. The upper substrate includes a fixed substrate, a square cutout, magnetoresistive power supply wires, a tunneling magnetoresistive element, a magnetoresistive signal transmission line, and a glass substrate. The fixed substrate is positioned above the lower substrate, with a square cutout at its center. This invention utilizes the tunneling magnetoresistive effect for detection, easily achieving full-circle detection by the angle sensor. Furthermore, the phase-shifting circuit combined with the subdivision circuit in the signal processing module improves the measurement resolution, providing a framework for achieving high-precision full-circle angle measurement using other magnetic angle sensors.

Description

Technical Field

[0001] This invention belongs to the technical field of angle detection devices, specifically relating to a high-sensitivity angle detection device based on the tunnel magnetoresistance effect. Background Technology

[0002] Angle measurement devices are widely used in various industrial fields, especially in the automotive, automation, and intelligent industries, playing a crucial role in autonomous driving, robotics, and automated production. Traditional angle sensors use resistive or strain gauge methods for angle measurement. While these methods are relatively simple in structure and principle, in practical applications, wear and error inevitably occur due to contact between the sensor and the object being measured, thus affecting measurement accuracy. Non-contact angular displacement sensors can effectively avoid these problems. Currently, non-contact angle sensors on the market can be divided into optical, capacitive, and magnetoresistive types based on their principles. Among them, capacitive angle sensors are greatly affected by the environment; in high-temperature, humid, and low-pressure environments, the measurement error of the sensor will increase significantly, and in severe cases, it may even fail. Optical angle measurement devices have high manufacturing costs and extremely high requirements for manufacturing process precision. Their measurement accuracy is often limited by the level of manufacturing technology, and they suffer from problems such as weak anti-interference ability, inability to work under harsh conditions, and difficulty in integration. Summary of the Invention

[0003] To address the technical problems of existing non-contact angle sensors, such as weak anti-interference capabilities, inability to operate under harsh conditions, and difficulty in integration, this invention provides a high-sensitivity angle detection device based on the tunnel magnetoresistive effect. By designing a tunnel magnetoresistive angle measurement device and combining a 90° phase-shifting circuit with a high-resolution subdivision circuit, highly sensitive angle detection can be achieved. This can improve the angle measurement accuracy by one to two orders of magnitude. The overall structure is simple, the manufacturing process is simple, and it is highly practical and easy to test.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0005] A high-sensitivity angle detection device based on tunnel magnetoresistive effect includes an upper substrate portion and a lower substrate portion. The upper substrate portion is disposed above the lower substrate portion, and the upper substrate portion and the lower substrate portion are parallel to each other and have no contact.

[0006] The upper substrate includes a fixed substrate, a square cutout, a magnetoresistive power supply wire, a tunnel magnetoresistive element, a magnetoresistive signal transmission line, and a glass substrate. The fixed substrate is disposed above the lower substrate, and a square cutout is formed at the center of the fixed substrate.

[0007] The tunnel magnetoresistive element is located at the center of the square cutout, and a glass substrate is installed below the square cutout of the fixed substrate. The tunnel magnetoresistive element is fixed on the glass substrate.

[0008] One end of the tunnel magnetoresistive element is electrically connected to a magnetoresistive power supply wire, and the other end of the tunnel magnetoresistive element is electrically connected to a magnetoresistive signal transmission line.

[0009] The lower substrate includes a permanent magnet, an angular displacement stage, and a lifting platform plane. The angular displacement stage is fixed on the lifting platform plane, and the permanent magnet is located at the center of the angular displacement stage.

[0010] The permanent magnet is positioned directly below the tunnel magnetoresistive element, and there is no contact between the permanent magnet and the tunnel magnetoresistive element.

[0011] The tunnel magnetoresistive element is electrically connected to the power supply via a magnetoresistive power supply wire. The tunnel magnetoresistive element is electrically connected to a phase-shifting module via a magnetoresistive signal transmission line. The phase-shifting module is electrically connected to a high-magnification subdivision processing module.

[0012] Compared with the prior art, the beneficial effects of this invention are:

[0013] 1. This invention uses the tunneling magnetoresistance effect for detection, which can easily achieve full-circle detection by the angle sensor. Secondly, the phase-shifting circuit in the signal processing module, combined with the subdivision circuit, improves the measurement resolution and provides a solution for other magnetic angle sensors to achieve high-precision full-circle angle measurement.

[0014] 2. The angle sensor of this invention uses a tunnel magnetoresistive element to output one signal, which is then passed through a 90° phase shift circuit to obtain another signal with the same amplitude and frequency but a 90° phase difference. This replaces the use of two sets of tunnel magnetoresistive units to form a full bridge structure, apply sine and cosine excitation to output two sine and cosine signals with a 90° phase difference, which can greatly reduce the amplitude and phase errors introduced during the test.

[0015] 3. This invention uses the highly sensitive tunnel magnetoresistive effect for angle detection. When the direction of the magnetic field changes, the resistance of the tunnel magnetoresistive element will change dramatically. The signal is first processed by a 90-degree shift combined with a high-magnification subdivision circuit to obtain the actual angle size, which can improve the accuracy of tunnel magnetoresistive angle detection by one to two orders of magnitude. Attached Figure Description

[0016] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0017] The structures, proportions, sizes, etc. illustrated in this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed herein, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0018] Figure 1 This is a schematic diagram of the structure of the present invention;

[0019] Figure 2 This is a schematic diagram of the upper substrate portion of the present invention;

[0020] Figure 3 This is a structural diagram of the permanent magnet of the present invention;

[0021] Figure 4 This is a schematic diagram of the circuit processing module structure of the present invention;

[0022] Figure 5 This is a schematic diagram of the high-magnification subdivision processing module of the present invention;

[0023] Figure 6 This is a schematic diagram of the high-magnification subdivision processing module receiving signals according to the present invention.

[0024] Wherein: 1 is the upper substrate, 101 is the fixed substrate, 102 is the square cutout, 103 is the magnetoresistive power supply wire, 104 is the tunnel magnetoresistive element, 105 is the magnetoresistive signal transmission line, 106 is the glass substrate, 2 is the lower substrate, 201 is the permanent magnet, 202 is the angular displacement stage, 203 is the lifting stage plane, 3 is the phase shifting module, and 4 is the high magnification subdivision processing module. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. These descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the claims of the present invention. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0027] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0028] In this embodiment, as Figure 1 As shown, the upper substrate portion 1 is located directly above the lower substrate portion 2. The upper substrate portion 1 and the lower substrate are parallel to each other. The upper substrate portion 1 and the lower substrate portion 2 can be very close but not in contact. The angle displacement stage 202 is fixed on the plane 203 of the lower lifting stage and is used to adjust the distance between the tunnel magnetoresistive element 104 and the permanent magnet 201. The permanent magnet 201 is placed at the center of the surface of the angle displacement stage 202.

[0029] Furthermore, such as Figure 2 , Figure 3 As shown, a square cutout 102 at the center of the fixed substrate 101 allows the tunnel magnetoresistive element 104 to be placed on the magnetoresistive glass substrate 106, reducing the distance between the tunnel magnetoresistive element 104 and the permanent magnet 201 and enabling precise centering for measurement. When the permanent magnet 201 rotates with the rotary displacement stage 202, the tunnel magnetoresistive element 104 undergoes a significant change, outputting an angle-related cosine signal through the magnetoresistive signal transmission line 105. Figure 4 As shown, the output signal is first transmitted to the phase shifting module 3 for processing, resulting in two signals with a 90° phase difference and the same amplitude and frequency. These two signals are then transmitted to the high-multiplication subdivision processing module 4 for subdivision interpolation processing, the principle of which is as follows: Figure 5 The external angular displacement is then calculated to complete the detection. Subdivision improves the resolution of the electrical signal, further enhancing the sensitivity of angle measurement, while also suppressing interference signals from the external environment. Figure 6 This diagram illustrates the signal received by the high-magnification subdivision processing module 4 in this embodiment. It shows two signals obtained through the phase-shifting module 3, with identical amplitude and frequency to the sensor output signal but a 90° phase difference. Finally, the externally input angular displacement is calculated to complete the detection.

[0030] Furthermore, the tunnel magnetoresistive high-sensitivity angle detection method of this embodiment first uses the rotation of the permanent magnet 201 to change the angle, thereby generating a changing magnetic field. When current is applied to the power supply wire 103 of the magnetoresistive element, the magnetization direction of the free layer in the tunnel magnetoresistive element 104 changes with the magnetic field. The angle between the magnetization directions of the free layer and the pinned layer gradually increases, resulting in a change in resistance. The angle is detected by measuring the change in resistance. Therefore, the tunnel magnetoresistive element 104 will generate a strong change in resistance based on this changing magnetic field, which serves as the input signal for the subsequent signal processing module. To achieve angle measurement, the signal is first processed by the phase-shifting processing module 3 to obtain two signals with a 90° phase difference and the same other characteristic values. The signals are then further subdivided by the high-magnification subdivision processing module 4 to obtain higher detection accuracy and resolution.

[0031] The above description only illustrates the preferred embodiments of the present invention. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention, and all such changes should be included within the protection scope of the present invention.

Claims

1. A high-sensitivity angle detection device based on tunneling magnetoresistance effect, characterized in that: The system includes an upper substrate portion (1) and a lower substrate portion (2). The upper substrate portion (1) is disposed above the lower substrate portion (2). The upper substrate portion (1) and the lower substrate portion (2) are parallel to each other and there is no contact between the upper substrate portion (1) and the lower substrate portion (2). The upper substrate portion (1) includes a fixed substrate (101), a square cutout (102), a magnetoresistive power supply wire (103), a tunnel magnetoresistive element (104), a magnetoresistive signal transmission line (105), and a glass substrate (106). The fixed substrate (101) is disposed above the lower substrate portion (2). Above 2), a square cutout (102) is provided at the center of the fixed substrate (101); one end of the tunnel magnetoresistive element (104) is electrically connected to a magnetoresistive power supply wire (103), and the other end of the tunnel magnetoresistive element (104) is electrically connected to a magnetoresistive signal transmission line (105); the tunnel magnetoresistive element (104) is electrically connected to the power supply through the magnetoresistive power supply wire (103), and the tunnel magnetoresistive element (104) is electrically connected to a phase shifting module (3) through the magnetoresistive signal transmission line (105), and the phase shifting module (3) is electrically connected to a high-magnification subdivision processing module (4).

2. The high-sensitivity angle detection device based on tunneling magnetoresistance effect according to claim 1, characterized in that: The tunnel magnetoresistive element (104) is disposed at the center of the square cutout (102), and a glass substrate (106) is installed below the square cutout (102) of the fixed substrate (101), and the tunnel magnetoresistive element (104) is fixed on the glass substrate (106).

3. The high-sensitivity angle detection device based on tunneling magnetoresistance effect according to claim 1, characterized in that: The lower substrate portion (2) includes a permanent magnet (201), an angle displacement stage (202), and a lifting platform plane (203). The angle displacement stage (202) is fixed on the lifting platform plane (203), and the permanent magnet (201) is located at the center of the angle displacement stage (202).

4. The high-sensitivity angle detection device based on tunneling magnetoresistance effect according to claim 3, characterized in that: The permanent magnet (201) is positioned directly below the tunnel magnetoresistive element (104), and there is no contact between the permanent magnet (201) and the tunnel magnetoresistive element (104).

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