Displacement measuring device, displacement measuring system and displacement measuring method

Abstract

The invention discloses a displacement measuring device, a displacement measuring system and a displacement measuring method. The displacement measuring device comprises a circuit board and two magnets. The circuit board comprises a linear magnetic induction array, and the linear magnetic induction array comprises a plurality of magnetic induction sensors which are arranged in a row in the first direction. The two magnets are arranged side by side in the first direction and adjacent to the linear magnetic induction array. The south poles of the two magnets face opposite directions, and the north poles of the two magnets face opposite directions. The two magnets can synchronously move between the front end and the rear end of the circuit board in the first direction relative to the circuit board. The distance between the two magnets is not smaller than twice of the distance between the two adjacent magnetic induction sensors, so that when the two magnets are moved to the front end or the rear end of the circuit board, the number of the magnetic induction sensors located in the effective magnetic field intensity area of the two magnets is at least two. Therefore, the number of the magnetic induction sensors participating in displacement measurement calculation can be increased, and the displacement measurement precision is improved.

Description

Technical Field

[0001] The invention relates to a displacement measuring device, comprising a displacement measuring system of the displacement measuring device and a displacement measuring method. Background Art

[0002] In the prior art, a linear magnetoresistive displacement measurement system generally includes a linear magnetoresistive (MR) sensor array and a single magnet. The single magnet can move along a linear direction relative to the linear magnetoresistive sensor array, and a plurality of magnetoresistive sensors in the linear magnetoresistive sensor array are arranged in a row along the linear direction.

[0003] In the prior art, a single magnet is moved above the linear magnetoresistive sensor array along the aforementioned straight line direction to achieve displacement measurement. However, when the single magnet is moved to the front end or rear end of the linear magnetoresistive sensor array, the single magnet is adjacent to only one magnetoresistive sensor, and only one magnetoresistive sensor is involved in the displacement measurement calculation, which results in poor displacement measurement accuracy when the single magnet is moved to the front end or rear end of the linear magnetoresistive sensor array, and cannot meet the measurement accuracy requirements expected by customers.

[0004] In addition, in the prior art, when a single magnet is moved to the middle position between the front end and the rear end of the linear magnetoresistive sensor array, the single magnet is adjacent to only two magnetoresistive sensors. At this time, only two magnetoresistive sensors participate in the displacement measurement calculation, which also results in poor displacement measurement accuracy when the single magnet is moved to the middle position of the linear magnetoresistive sensor array, and cannot meet the measurement accuracy requirements expected by customers. Summary of the invention

[0005] The purpose of the present invention is to solve at least one aspect of the above-mentioned problems and defects in the prior art.

[0006] According to one aspect of the present invention, a displacement measuring device is provided. The displacement measuring device comprises: a circuit board and two magnets. The circuit board comprises a linear magnetic induction array, and the linear magnetic induction array comprises a plurality of magnetic induction sensors arranged in a row along a first direction. Two magnets are arranged side by side in the first direction and adjacent to the circuit board. The south poles of the two magnets face opposite directions, and the north poles of the two magnets face opposite directions. The two magnets can be synchronously moved between the front end and the rear end of the circuit board along the first direction relative to the circuit board. The spacing D2 between the two magnets is not less than twice the spacing D1 between two adjacent magnetic induction sensors, so that when the two magnets are moved to the front end or the rear end of the circuit board, the number of magnetic induction sensors located in the effective magnetic field strength area of ​​the two magnets is at least two.

[0007] According to another exemplary embodiment of the present invention, when the two magnets move to a middle position between the front end and the rear end of the circuit board, the number of magnetic induction sensors located in the effective magnetic field strength area of ​​the two magnets is at least three.

[0008] According to another exemplary embodiment of the present invention, the distance D2 between the two magnets is equal to twice the distance D1 between the two adjacent magnetic induction sensors, so that when the two magnets move to the front end or the rear end of the circuit board, the number of magnetic induction sensors located in the effective magnetic field strength area of ​​the two magnets is two or three.

[0009] According to another exemplary embodiment of the present invention, when the two magnets move to a middle position between the front end and the rear end of the circuit board, the number of magnetic induction sensors located in the effective magnetic field strength area of ​​the two magnets is three or four.

[0010] According to another exemplary embodiment of the present invention, the distance D2 between the two magnets is equal to three times the distance D1 between the two adjacent magnetic induction sensors, so that when the two magnets move to the front end or the rear end of the circuit board, the number of magnetic induction sensors located in the effective magnetic field strength area of ​​the two magnets is three.

[0011] According to another exemplary embodiment of the present invention, when the two magnets move to a middle position between the front end and the rear end of the circuit board, the number of magnetic induction sensors located in the effective magnetic field strength area of ​​the two magnets is four.

[0012] According to another exemplary embodiment of the present invention, the distance D2 between the two magnets is equal to four times the distance D1 between the two adjacent magnetic induction sensors, so that when the two magnets move to the front end or the rear end of the circuit board, the number of magnetic induction sensors located in the effective magnetic field strength area of ​​the two magnets is three.

[0013] According to another exemplary embodiment of the present invention, when the two magnets are moved to a middle position between the front end and the rear end of the circuit board, the number of magnetic induction sensors located in the effective magnetic field strength area of ​​the two magnets is four.

[0014] According to another exemplary embodiment of the present invention, the circuit board extends along the first direction and a second direction perpendicular to the first direction; the magnet is a bar magnet, and the south pole and the north pole of the magnet are opposite in the second direction.

[0015] According to another exemplary embodiment of the present invention, the magnetic induction sensor is a magnetoresistive sensor or a Hall sensor for detecting magnetic field strength.

[0016] According to another aspect of the present invention, a displacement measurement system is provided. The displacement measurement system comprises: the aforementioned displacement measurement device; a signal acquisition unit for acquiring magnetic field strength signals detected by a magnetic induction sensor located in the effective magnetic field strength region of the two magnets; a position calculation unit for calculating the current position of the central symmetric point between the two magnets in the first direction according to the acquired magnetic field strength signals; and a displacement calculation unit for calculating the displacement S of the two magnets in the first direction according to the following formula,

[0017] S=P1-P0

[0018] in,

[0019] P1 is the calculated current position P1 of the central symmetric point between the two magnets,

[0020] P0 is the initial position P0 of the central symmetric point between the two magnets, and the initial position P0 is known.

[0021] According to an exemplary embodiment of the present invention, the signal acquisition unit is integrated into the circuit board and is electrically connected to the plurality of magnetic induction sensors via conductive traces on the circuit board.

[0022] According to another exemplary embodiment of the present invention, the signal acquisition unit is electrically connected to the circuit board and is electrically connected to the plurality of magnetic induction sensors via conductive traces on the circuit board.

[0023] According to another exemplary embodiment of the present invention, the position calculation unit is communicatively connected to the signal acquisition unit for receiving the magnetic field strength signal acquired by the signal acquisition unit; the displacement calculation unit is communicatively connected to the position calculation unit for receiving the current position P1 of the central symmetrical point between the two magnets calculated by the position calculation unit.

[0024] According to another aspect of the present invention, there is provided a displacement measurement method, comprising the following steps:

[0025] S10: providing the aforementioned displacement measurement system;

[0026] S20: synchronously moving the two magnets along the first direction;

[0027] S30: collecting magnetic field strength signals detected by magnetic induction sensors located in the effective magnetic field strength area of ​​the two magnets;

[0028] S40: calculating the current position of the central symmetric point between the two magnets in the first direction according to the collected magnetic field strength signal; and

[0029] S50: Calculate the displacement S of the two magnets in the first direction according to the calculated current position P1 of the central symmetric point between the two magnets and the calculated initial position P0 of the central symmetric point between the two magnets.

[0030] In the aforementioned exemplary embodiments of the present invention, the spacing between the two magnets is not less than twice the spacing between two adjacent magnetic induction sensors, so that when the two magnets are moved to the front end or the rear end of the linear magnetic induction sensor array, the number of magnetic induction sensors located in the effective magnetic field strength area of ​​the two magnets is at least two, thereby increasing the number of magnetic induction sensors participating in the displacement measurement calculation and improving the displacement measurement accuracy.

[0031] In the aforementioned exemplary embodiments of the present invention, the spacing between the two magnets is not less than twice the spacing between two adjacent magnetic induction sensors, so that when the two magnets are moved to the middle position between the two ends of the linear magnetic induction sensor array, the number of magnetic induction sensors located in the effective magnetic field strength area of ​​the two magnets is at least three, thereby increasing the number of magnetic induction sensors participating in the displacement measurement calculation and improving the displacement measurement accuracy.

[0032] Other objects and advantages of the present invention will become apparent from the following description of the present invention with reference to the accompanying drawings, which will help to provide a comprehensive understanding of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A schematic diagram showing a displacement measuring device according to an exemplary first embodiment of the present invention, wherein two magnets are located at a middle position between the front end and the rear end of a circuit board;

[0034] Figure 2 A schematic diagram showing a displacement measuring device according to an exemplary first embodiment of the present invention, wherein two magnets are located at the front end of a circuit board;

[0035] Figure 3 A schematic diagram showing a displacement measuring device according to an exemplary first embodiment of the present invention, wherein two magnets are located at the rear end of a circuit board;

[0036] Figure 4 A schematic diagram showing a displacement measuring device according to an exemplary second embodiment of the present invention, wherein two magnets are located at a middle position between the front end and the rear end of a circuit board;

[0037] Figure 5 A schematic diagram showing a displacement measuring device according to an exemplary second embodiment of the present invention, wherein two magnets are located at the front end of a circuit board;

[0038] Figure 6 A schematic diagram showing a displacement measuring device according to an exemplary second embodiment of the present invention, wherein two magnets are located at the rear end of a circuit board;

[0039] Figure 7 A schematic diagram showing a displacement measuring device according to an exemplary third embodiment of the present invention, wherein two magnets are located at a middle position between the front end and the rear end of the circuit board;

[0040] Figure 8 A schematic diagram showing a displacement measuring device according to an exemplary third embodiment of the present invention, wherein two magnets are located at the front end of a circuit board;

[0041] Fig. 9 A schematic diagram showing a displacement measuring device according to an exemplary third embodiment of the present invention is shown, wherein two magnets are located at the rear end of a circuit board. DETAILED DESCRIPTION

[0042] The technical solution of the present invention is further specifically described below by examples and in conjunction with the accompanying drawings. In the specification, the same or similar reference numerals indicate the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the overall inventive concept of the present invention and should not be construed as a limitation of the present invention.

[0043] In addition, in the detailed description below, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the disclosed embodiments. However, it is apparent that one or more embodiments may be implemented without these specific details. In other cases, known structures and devices are embodied in a schematic manner to simplify the accompanying drawings.

[0044] According to an overall technical concept of the present invention, a displacement measuring device is provided. The displacement measuring device includes: a circuit board and two magnets. The circuit board includes a linear magnetic induction array, and the linear magnetic induction array includes a plurality of magnetic induction sensors arranged in a row along a first direction. Two magnets are arranged side by side in the first direction and adjacent to the circuit board. The south poles of the two magnets face opposite directions, and the north poles of the two magnets face opposite directions. The two magnets can be synchronously moved between the front end and the rear end of the circuit board along the first direction relative to the circuit board. The spacing D2 between the two magnets is not less than twice the spacing D1 between two adjacent magnetic induction sensors, so that when the two magnets are moved to the front end or the rear end of the circuit board, the number of magnetic induction sensors located in the effective magnetic field strength area of ​​the two magnets is at least two.

[0045] According to another general technical concept of the present invention, a displacement measurement system is provided. The displacement measurement system includes: the aforementioned displacement measurement device; a signal acquisition unit for acquiring magnetic field strength signals detected by a magnetic induction sensor located in the effective magnetic field strength area of ​​the two magnets; a position calculation unit for calculating the current position of the central symmetric point between the two magnets in the first direction according to the acquired magnetic field strength signal; and a displacement calculation unit for calculating the displacement S of the two magnets in the first direction according to the formula S=P1-P0, wherein P1 is the calculated current position of the central symmetric point between the two magnets, and P0 is the initial position of the central symmetric point between the two magnets, and the initial position P0 is known.

[0046] According to another overall technical concept of the present invention, a displacement measurement method is provided, comprising the following steps: providing the aforementioned displacement measurement system; synchronously moving the two magnets along the first direction; collecting magnetic field strength signals detected by the magnetic induction sensor located in the effective magnetic field strength area of ​​the two magnets; calculating the current position of the central symmetrical point between the two magnets in the first direction based on the collected magnetic field strength signals; and calculating the displacement S of the two magnets in the first direction based on the calculated current position P1 of the central symmetrical point between the two magnets and the initial position P0 of the central symmetrical point between the two magnets.

[0047] First embodiment

[0048] Figures 1 to 3 The displacement measuring device according to the exemplary first embodiment of the present invention is shown. Figure 1 A schematic diagram showing a displacement measuring device according to an exemplary first embodiment of the present invention, wherein two magnets 21, 22 are located in the middle between the front end and the rear end of the circuit board 1; Figure 2 A schematic diagram showing a displacement measuring device according to an exemplary first embodiment of the present invention, wherein two magnets 21, 22 are located at the front end of a circuit board 1; Figure 3 A schematic diagram showing a displacement measuring device according to an exemplary first embodiment of the present invention is shown, wherein two magnets 21 , 22 are located at the rear end of a circuit board 1 .

[0049] like Figures 1 to 3As shown, in an exemplary embodiment of the present invention, a displacement measuring device is disclosed. The displacement measuring device includes: a circuit board 1 and two magnets 21, 22. The circuit board 1 is in a long strip shape and includes a linear magnetic induction array arranged thereon. The linear magnetic induction array includes a plurality of magnetic induction sensors 10 arranged in a row along a first direction Y. The two magnets 21, 22 are arranged side by side in the first direction Y and are adjacent to the linear magnetic induction array. In the illustrated embodiment, the two magnets 21, 22 are located above the magnetic induction sensor 10.

[0050] like Figures 1 to 3 As shown, in the illustrated embodiment, the south poles S of the two magnets 21 and 22 face opposite directions, and the north poles N of the two magnets 21 and 22 face opposite directions. In the illustrated embodiment, the south pole S of the magnet 21 faces downward, and the south pole S of the magnet 22 faces upward. The north pole N of the magnet 21 faces upward, and the north pole N of the magnet 22 faces downward.

[0051] like Figures 1 to 3 As shown, in the illustrated embodiment, the two magnets 21, 22 can be synchronously moved between the front end and the rear end of the circuit board 1 along the first direction Y relative to the circuit board 1. In the illustrated embodiment, the spacing D2 between the two magnets 21, 22 is equal to twice the spacing D1 between two adjacent magnetic induction sensors 10, so that when the two magnets 21, 22 are moved to the front end or the rear end of the circuit board 1, the number of magnetic induction sensors 10 located in the effective magnetic field strength area of ​​the two magnets 21, 22 is two or three. The effective magnetic field strength area in this article refers to a magnetic field area with a magnetic field strength greater than a predetermined threshold value. For example, the effective magnetic field strength area can be an area where the distance to the magnets 21, 22 in the first direction Y is not greater than the spacing D1.

[0052] like Figures 1 to 3 As shown, in the illustrated embodiment, when the two magnets 21, 22 are moved to the middle position between the front end and the rear end of the circuit board 1, the number of magnetic induction sensors 10 located in the effective magnetic field strength area of ​​the two magnets 21, 22 is three or four.

[0053] like Figures 1 to 3 As shown, in the illustrated embodiment, the circuit board 1 extends along a first direction Y and a second direction X perpendicular to the first direction Y. The magnets 21 and 22 are bar magnets, and the south pole S and the north pole N of the magnets 21 and 22 are opposite in the second direction X.

[0054] like Figures 1 to 3 As shown, in the illustrated embodiment, the magnetic induction sensor 10 may be a magnetoresistive sensor or a Hall sensor for detecting the strength of a magnetic field.

[0055] like Figures 1 to 3As shown, in another exemplary embodiment of the present invention, a displacement measurement system is also disclosed. The displacement measurement system includes: the aforementioned displacement measurement device, a signal acquisition unit (not shown), a position calculation unit (not shown) and a displacement calculation unit (not shown). The signal acquisition unit is used to collect the magnetic field strength signal detected by the magnetic induction sensor 10 located in the effective magnetic field strength area of ​​the two magnets 21 and 22. The position calculation unit (which can be a functional module combining software and hardware, for example, it can include a microprocessor and a computer program running in the microprocessor) is used to calculate the current position of the central symmetrical point O between the two magnets 21 and 22 in the first direction Y based on the collected magnetic field strength signal. The displacement calculation unit (which can be a functional module combining software and hardware, for example, it can include a microprocessor and a computer program running in the microprocessor) calculates the displacement S of the two magnets 21 and 22 in the first direction Y according to the following formula,

[0056] S=P1-P0

[0057] in,

[0058] P1 is the calculated current position of the central symmetric point O between the two magnets 21 and 22,

[0059] P0 is the initial position of the central symmetric point O between the two magnets 21 and 22 , and the initial position P0 is known.

[0060] like Figures 1 to 3 As shown, in an exemplary embodiment of the present invention, the signal acquisition unit may be integrated into the circuit board 1 and electrically connected to the plurality of magnetic induction sensors 10 via conductive traces on the circuit board 1 .

[0061] like Figures 1 to 3 As shown, in another exemplary embodiment of the present invention, the signal acquisition unit may be independent of the circuit board 1 and electrically connected to the circuit board 1. In this way, the signal acquisition unit may be electrically connected to the plurality of magnetic induction sensors 10 via the conductive traces on the circuit board 1.

[0062] like Figures 1 to 3 As shown, in the illustrated embodiment, the position calculation unit is connected in communication with the signal acquisition unit to receive the magnetic field strength signal acquired by the signal acquisition unit. The displacement calculation unit is connected in communication with the position calculation unit to receive the current position P1 of the central symmetric point O between the two magnets 21 and 22 calculated by the position calculation unit.

[0063] like Figures 1 to 3 As shown, in another exemplary embodiment of the present invention, a displacement measurement method is also disclosed. The displacement measurement method comprises the following steps:

[0064] S10: Providing a displacement measurement system according to any one of claims 11 to 14;

[0065] S20: synchronously moving the two magnets 21 and 22 along the first direction Y;

[0066] S30: collecting magnetic field strength signals detected by the magnetic induction sensor 10 located in the effective magnetic field strength area of ​​the two magnets 21 and 22;

[0067] S40: Calculate the current position of the central symmetric point O between the two magnets 21 and 22 in the first direction Y according to the collected magnetic field strength signal; and

[0068] S50 : Calculate the displacement S of the two magnets 21 , 22 in the first direction Y according to the calculated current position P1 of the central symmetric point O between the two magnets 21 , 22 and the calculated initial position P0 of the central symmetric point O between the two magnets 21 , 22 .

[0069] Second embodiment

[0070] Figures 4 to 6 A displacement measuring device according to an exemplary second embodiment of the present invention is shown. Figure 4 A schematic diagram showing a displacement measuring device according to an exemplary second embodiment of the present invention, wherein two magnets 21, 22 are located in the middle between the front end and the rear end of the circuit board 1; Figure 5 A schematic diagram showing a displacement measuring device according to an exemplary second embodiment of the present invention, wherein two magnets 21, 22 are located at the front end of a circuit board 1; Figure 6 A schematic diagram showing a displacement measuring device according to an exemplary second embodiment of the present invention is shown, wherein two magnets 21 , 22 are located at the rear end of a circuit board 1 .

[0071] Figures 4 to 6 The second embodiment of the displacement measuring device shown is Figures 1 to 3 The first exemplary embodiment of the displacement measuring device shown differs mainly in that the distance D2 between the two magnets 21 , 22 is different.

[0072] like Figures 4 to 6 As shown, in the illustrated embodiment, the distance D2 between the two magnets 21, 22 is equal to three times the distance D1 between two adjacent magnetic induction sensors 10, so that when the two magnets 21, 22 are moved to the front end or the rear end of the circuit board 1, the number of magnetic induction sensors 10 located in the effective magnetic field strength area of ​​the two magnets 21, 22 is three.

[0073] like Figures 4 to 6As shown, in the illustrated embodiment, when the two magnets 21, 22 are moved to a middle position between the front end and the rear end of the circuit board 1, the number of magnetic induction sensors 10 located in the effective magnetic field strength area of ​​the two magnets 21, 22 is four.

[0074] In addition to the above differences, Figures 4 to 6 Other technical features of the displacement measuring device shown are similar to Figures 1 to 3 The displacement measuring device shown is basically the same and can be referred to Figures 1 to 3 For the sake of brevity, the displacement measuring device shown will not be described in detail here.

[0075] Third embodiment

[0076] Figures 7 to 9 FIG. 2 shows a displacement measuring device according to an exemplary third embodiment of the present invention. Figure 7 A schematic diagram showing a displacement measuring device according to an exemplary third embodiment of the present invention, wherein two magnets 21, 22 are located in the middle between the front end and the rear end of the circuit board 1; Figure 8 A schematic diagram showing a displacement measuring device according to an exemplary third embodiment of the present invention, wherein two magnets 21, 22 are located at the front end of a circuit board 1; Fig. 9 A schematic diagram showing a displacement measuring device according to an exemplary third embodiment of the present invention is shown, wherein two magnets 21 , 22 are located at the rear end of a circuit board 1 .

[0077] Figures 7 to 9 The third embodiment of the displacement measuring device shown is Figures 1 to 3 The first exemplary embodiment of the displacement measuring device shown differs mainly in that the distance D2 between the two magnets 21 , 22 is different.

[0078] like Figures 7 to 9 As shown, in the illustrated embodiment, the distance D2 between the two magnets 21, 22 is equal to four times the distance D1 between two adjacent magnetic induction sensors 10, so that when the two magnets 21, 22 are moved to the front end or the rear end of the circuit board 1, the number of magnetic induction sensors 10 located in the effective magnetic field strength area of ​​the two magnets 21, 22 is three.

[0079] like Figures 7 to 9 As shown, in the illustrated embodiment, when the two magnets 21, 22 are moved to a middle position between the front end and the rear end of the circuit board 1, the number of magnetic induction sensors 10 located in the effective magnetic field strength area of ​​the two magnets 21, 22 is four.

[0080] In addition to the above differences, Figures 7 to 9 Other technical features of the displacement measuring device shown are similar to Figures 1 to 3The displacement measuring device shown is basically the same and can be referred to Figures 1 to 3 For the sake of brevity, the displacement measuring device shown will not be described in detail here.

[0081] like Figures 1 to 9 As shown, in the aforementioned embodiment, the two magnets 21, 22 can move along the entire magnetic induction sensor array, and the accuracy is improved not only at the front end or the rear end of the circuit board 1, but also at other places of the circuit board 1. In the illustrated embodiment, at least two magnetic induction sensors 10 are located in the effective magnetic field strength area of ​​the two magnets 21, 22 at the end of the circuit board 1, so at least two magnetic induction sensors 10 at the end of the circuit board 1 participate in the position calculation, and at least three magnetic induction sensors 10 are located in the effective magnetic field strength area of ​​the two magnets 21, 22 at the middle part of the circuit board 1, so at least three magnetic induction sensors 10 at the middle part of the circuit board 1 participate in the position calculation.

[0082] like Figures 1 to 9 As shown, in the above-mentioned embodiment, the present invention can improve the measurement accuracy, not only because the number of magnetic induction sensors involved in the position calculation is increased, but also because the combination of two magnets 21 and 22 with opposite polarities changes the magnetic field distribution in the space around the magnets, and the magnetic induction curve (magnet distance and magnetic induction intensity relationship curve) of the magnetic induction sensor has a wider linear region, thereby improving the measurement accuracy. It can be understood by those skilled in the art that the embodiments described above are exemplary, and those skilled in the art can improve them. The structures described in various embodiments can be freely combined without conflicts in structure or principle, and these changes should fall within the scope of protection of the present invention.

[0083] Although the present invention has been described in conjunction with the accompanying drawings, the embodiments disclosed in the accompanying drawings are intended to exemplify the preferred implementations of the present invention and should not be construed as limiting the present invention.

[0084] Although some embodiments of the general inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the general inventive concept, the scope of which is defined in the claims and their equivalents.

[0085] It should be noted that the word "comprising" does not exclude other elements or steps, and the word "a" or "an" does not exclude a plurality. In addition, any element reference signs in the claims shall not be construed as limiting the scope of the present invention.

Claims

1. A displacement measuring device, characterized in that: include: A circuit board (1), comprising: A linear magnetic induction array comprises a plurality of magnetic induction sensors (10) arranged in a row along a first direction (Y); and Two magnets (21, 22) are arranged side by side in the first direction (Y) and adjacent to the linear magnetic induction array, The south poles (S) of the two magnets (21, 22) face in opposite directions, and the north poles (N) of the two magnets (21, 22) face in opposite directions, The two magnets (21, 22) are capable of synchronously moving relative to the circuit board (1) along the first direction (Y) between the front end and the rear end of the circuit board (1), The spacing D2 between the two magnets (21, 22) is not less than twice the spacing D1 between two adjacent magnetic induction sensors (10), so that when the two magnets (21, 22) are moved to the front end or the rear end of the circuit board (1), the number of magnetic induction sensors (10) located in the effective magnetic field strength area of ​​the two magnets (21, 22) is at least two.

2. The displacement measuring device according to claim 1, characterized in that: When the two magnets (21, 22) are moved to an intermediate position between the front end and the rear end of the circuit board (1), the number of magnetic induction sensors (10) located in the effective magnetic field strength area of ​​the two magnets (21, 22) is at least three.

3. The displacement measuring device according to claim 1 or 2, characterized in that: The spacing D2 between the two magnets (21, 22) is equal to twice the spacing D1 between the two adjacent magnetic induction sensors (10), so that when the two magnets (21, 22) are moved to the front end or the rear end of the circuit board (1), the number of magnetic induction sensors (10) located in the effective magnetic field strength area of ​​the two magnets (21, 22) is two or three.

4. The displacement measuring device according to claim 3, characterized in that: When the two magnets (21, 22) are moved to a middle position between the front end and the rear end of the circuit board (1), the number of magnetic induction sensors (10) located in the effective magnetic field strength area of ​​the two magnets (21, 22) is three or four.

5. The displacement measuring device according to claim 1 or 2, characterized in that: The spacing D2 between the two magnets (21, 22) is equal to three times the spacing D1 between the two adjacent magnetic induction sensors (10), so that when the two magnets (21, 22) are moved to the front end or the rear end of the circuit board (1), the number of magnetic induction sensors (10) located in the effective magnetic field strength area of ​​the two magnets (21, 22) is three.

6. The displacement measuring device according to claim 5, characterized in that: When the two magnets (21, 22) are moved to a middle position between the front end and the rear end of the circuit board (1), the number of magnetic induction sensors (10) located in the effective magnetic field strength area of ​​the two magnets (21, 22) is four.

7. The displacement measuring device according to claim 1 or 2, characterized in that: The spacing D2 between the two magnets (21, 22) is equal to four times the spacing D1 between the two adjacent magnetic induction sensors (10), so that when the two magnets (21, 22) are moved to the front end or the rear end of the circuit board (1), the number of magnetic induction sensors (10) located in the effective magnetic field strength area of ​​the two magnets (21, 22) is three.

8. The displacement measuring device according to claim 7, characterized in that: When the two magnets (21, 22) are moved to a middle position between the front end and the rear end of the circuit board (1), the number of magnetic induction sensors (10) located in the effective magnetic field strength area of ​​the two magnets (21, 22) is four.

9. The displacement measuring device according to claim 1, characterized in that: The circuit board (1) extends along the first direction (Y) and a second direction (X) perpendicular to the first direction (Y); The magnets (21, 22) are bar magnets, and the south poles (S) and north poles (N) of the magnets (21, 22) are opposite to each other in the second direction (X).

10. The displacement measuring device according to claim 1, characterized in that: The magnetic induction sensor (10) is a magnetoresistive sensor or a Hall sensor for detecting the intensity of a magnetic field.

11. A displacement measurement system, characterized in that: include: The displacement measuring device according to any one of claims 1 to 10; A signal acquisition unit, used for acquiring a magnetic field intensity signal detected by a magnetic induction sensor (10) located in an effective magnetic field intensity region of the two magnets (21, 22); A position calculation unit, used for calculating the current position of the central symmetric point (O) between the two magnets (21, 22) in the first direction (Y) according to the collected magnetic field strength signal; and A displacement calculation unit calculates the displacement S of the two magnets (21, 22) in the first direction (Y) according to the following formula, S=P1-P0 in, P1 is the calculated current position P1 of the central symmetric point (O) between the two magnets (21, 22), P0 is the initial position P0 of the central symmetric point (O) between the two magnets (21, 22), and the initial position P0 is known.

12. The displacement measurement system according to claim 11, characterized in that: The signal acquisition unit is integrated onto the circuit board (1) and is electrically connected to the plurality of magnetic induction sensors (10) via conductive traces on the circuit board (1).

13. The displacement measurement system according to claim 11, characterized in that: The signal acquisition unit is electrically connected to the circuit board (1) and is electrically connected to the plurality of magnetic induction sensors (10) via conductive traces on the circuit board (1).

14. The displacement measurement system according to claim 11, characterized in that: The position calculation unit is in communication with the signal acquisition unit and is used to receive the magnetic field strength signal acquired by the signal acquisition unit; and The displacement calculation unit is in communication connection with the position calculation unit and is used to receive the current position P1 of the central symmetric point (O) between the two magnets (21, 22) calculated by the position calculation unit.

15. A displacement measurement method, characterized in that: The following steps are involved: S10: Provide a displacement measurement system as described in any one of claims 11 to 14; S20: synchronously moving the two magnets (21, 22) along the first direction (Y); S30: collecting magnetic field intensity signals detected by a magnetic induction sensor (10) located in an effective magnetic field intensity region of the two magnets (21, 22); S40: calculating the current position of the central symmetric point (O) between the two magnets (21, 22) in the first direction (Y) according to the collected magnetic field strength signal; and S50: Calculate the displacement S of the two magnets (21, 22) in the first direction (Y) based on the calculated current position P1 of the central symmetrical point (O) between the two magnets (21, 22) and the initial position P0 of the central symmetrical point (O) between the two magnets (21, 22).

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