Meter measurement device based on magnetic field polarity sensing
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-06-05
- Publication Date
- 2026-08-13
Smart Images
Figure CN2025099230_13082026_PF_FP_ABST
Abstract
Description
An instrument metering device based on magnetic field polarity sensing Technical Field
[0001] This invention relates to the field of metrology and testing technology, and more specifically to an instrument metrology device based on magnetic field polarity sensing. Background Technology
[0002] Traditional metering, such as gas metering or water metering, often uses optical sampling technology due to its excellent anti-interference capabilities. However, ordinary optical sampling technology suffers from drawbacks such as high complexity, high power consumption, and low resolution, typically achieving only a metering resolution of 0.01 (m³), which is insufficient for higher metering accuracy. To achieve more precise measurements, magnetoresistive sampling is commonly used in current technologies, offering higher metering resolution, typically reaching 0.002 (m³). This high metering resolution makes magnetoresistive sampling technology a significant advantage in applications requiring high-precision measurement.
[0003] In existing magnetoresistive sampling technology, when the fluid to be measured flows through the instrument, it drives the magnet assembly to rotate. At this time, a magnetic field sensing device is placed at a specific position near the rotating magnet assembly. The magnetic field sensing device detects the presence or absence of a magnetic field. When the magnet assembly moves to the position furthest from the magnetic field sensing device, the sensing device detects the magnetic field strength at its weakest level, and then outputs a corresponding electrical signal. When the magnet assembly moves to the position closest to the magnetic field sensing device, the sensing device detects the magnetic field strength at its strongest level, and then outputs another corresponding electrical signal. The processing unit can then obtain the measurement result by analyzing the changes in the quantity, timing, and frequency of the two electrical signals.
[0004] While the aforementioned measurement methods offer high accuracy and can meet the application requirements of most high-precision measurement scenarios, they also have certain drawbacks. Firstly, to ensure a relatively large distance between the magnet assembly and the sensing device, allowing the sensing device to clearly distinguish the different magnetic field strengths at the two extreme positions of the magnet assembly and guarantee the accuracy of acquiring two different electrical signals, a larger operating space is required. This places higher demands on hardware layout space, leading to increased instrument size and manufacturing costs. Secondly, the presence of external interfering magnetic fields can impair the sensing accuracy of the sensing device, causing misidentification of electrical signals and resulting in serious measurement errors. Summary of the Invention
[0005] The purpose of this invention is to provide an instrument measurement device based on magnetic field polarity sensing, which can complete the measurement action with a small device size while ensuring high measurement accuracy, and has better anti-interference ability, and can be competent for various high-precision measurement tasks.
[0006] To achieve the above objectives, the specific technical solution adopted by the present invention is as follows:
[0007] A metering device based on magnetic field polarity sensing includes a rotating component driven by a fluid, a magnetic sensitive device, and a magnetic field generating device. The rotating component is connected to the magnetic sensitive device or the magnetic field generating device and drives the magnetic sensitive device or the magnetic field generating device to rotate on a device arrangement track. The magnetic field generating device includes at least one magnetic pole pair.
[0008] As a preferred embodiment of the present invention, the device arrangement track includes a first circular track and a second circular track; the diameter of the first circular track is smaller than the diameter of the second circular track.
[0009] As a preferred embodiment of the present invention, the magnetic field generating device comprises n magnetic pole pairs, each of which comprises two magnetic poles with opposite polarities.
[0010] As a preferred embodiment of the present invention, the 2n magnetic poles in one of the magnetic field generating devices are evenly and alternately distributed, dividing the track surface of the device arrangement track into 2n sector-shaped magnetic pole induction areas, and the central angle of each sector-shaped magnetic pole induction area is α=360° / (2n).
[0011] As a preferred embodiment of the present invention, the track surface of the device arrangement track is mapped with a reference positioning surface, and the reference positioning surface contains 2n primary positioning sectors; the central angle α' of the primary positioning sector is the same as the central angle α of the sector-shaped magnetic pole induction area; each primary positioning sector contains m secondary positioning sectors, where m is the number of magnetic sensitive devices arranged; the central angle of each secondary positioning sector is β=α' / m.
[0012] As a preferred embodiment of the present invention, one of the circumferential directions of the reference positioning surface is selected as the positioning direction, and the m secondary positioning sectors contained in each primary positioning sector are sequentially marked as the first feature area to the mth feature area according to the positioning direction; the m magnetic sensitive devices are fixedly arranged in the feature areas and fall on the device arrangement track; the feature area marking numbers of each magnetic sensitive device are different.
[0013] As a preferred embodiment of the present invention, the rotating component is connected to the magnetic field generating device and drives the magnetic field generating device to rotate on the second circular track; the magnetic field generating device includes two magnetic pole pairs, dividing the track surface of the device arrangement track into four sector-shaped magnetic pole induction areas, and the central angle of each sector-shaped magnetic pole induction area is α=90°; two magnetic sensitive devices are fixedly arranged on the first circular track, and the two magnetic sensitive devices are located in two secondary positioning sectors with different feature area marking numbers.
[0014] As a preferred embodiment of the present invention, the magnetic sensitive devices fixedly arranged in each of the secondary positioning sectors are all located on the sector center line of the secondary positioning sector.
[0015] As a preferred embodiment of the present invention, the magnetic sensitive device and the magnetic field generating device are wrapped with a shielding layer on their outer sides, and the shielding layer is used to resist external magnetic interference.
[0016] As a preferred embodiment of the present invention, the instrument measurement device further includes a processor electrically connected to all of the magnetic sensing devices for collecting detection signals sent by the magnetic sensing devices and performing measurement.
[0017] In summary, the present invention has the following beneficial effects:
[0018] The magnetic sensor can determine the polarity of the current magnetic field. Since the rotating component will drive one part of the magnetic sensor or magnetic field generator to rotate, while the other part is fixed in a specific secondary positioning sector, the magnetic sensor rotates relative to the magnetic field generator on the device arrangement track. During this relative rotation, the magnetic sensor can generate different detection signals according to different magnetic field polarities. The processor can calculate the flow data based on the detection signal. In this process, the relative distance between the magnetic field generator and the magnetic sensor does not need to be set too large to obtain accurate measurement data, which greatly reduces the size of the instrument device.
[0019] Based on the distribution of magnetic pole pairs in the magnetic field generator, the track surface of the device arrangement track was divided into regions. It was divided into multiple sector-shaped magnetic pole induction zones, corresponding sequentially to different uniformly alternating magnetic field polarities. Furthermore, based on 2n sector-shaped magnetic pole induction zones, 2n primary positioning sectors were mapped, and combined with the preset number of magnetic sensing devices, the primary positioning sectors were further divided into m secondary positioning sectors. This further precisely defined the arrangement zones and positions of the magnetic sensing devices. Combined with the selection rules of the feature area markers, the angular relationship between the multiple magnetic sensing devices was defined. This angular relationship ensures that for any unit degree rotation of the sector-shaped magnetic pole induction zone relative to the magnetic sensing device, at least one magnetic sensing device can acquire a detection signal, thereby obtaining continuous, complete, and accurate measurement data.
[0020] A shielding layer is wrapped around the magnetic sensing device and magnetic field generating device to resist external magnetic interference. Since the instrument's measuring device is small in size, fewer shielding layers are needed to complete the wrapping and coverage, which also reduces the extra weight brought by the additional shielding layer. Attached Figure Description
[0021] The accompanying drawings are only used to illustrate the principles, implementation methods, applications, features, and effects of specific embodiments of this application and other related content, and should not be considered as limitations on this application.
[0022] Figure 1 is a schematic diagram of the structure of this metering device;
[0023] Figure 2 is a schematic diagram of the device arrangement in Example 5;
[0024] Figure 3 is a schematic diagram of the device arrangement in Example 7;
[0025] Figure 4 is a schematic diagram of the device arrangement in Example 8.
[0026] In the diagram: 1. Magnetic sensitive device; 2. Magnetic field generating device; 3. Device arrangement track; 31. First circular track; 32. Second circular track. Detailed Implementation
[0027] The technical solutions of the embodiments of the present invention will be explained and described below with reference to the accompanying drawings. However, the following embodiments are only preferred embodiments of the present invention and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments in the implementation methods without creative effort are all within the protection scope of the present invention.
[0028] The terms "first," "second," etc., in the description, claims, and accompanying drawings are used to distinguish different objects and not to describe a particular order. Furthermore, the term "comprising" and any variations thereof are intended to cover a non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such processes, methods, products, or apparatus.
[0029] As shown in Figure 1, this metering device measures fluids based on the principle of magnetic field polarity sensing. The fluids include, but are not limited to, common fuel gases or tap water. When the fluid flows through the pipeline, the metering device drives a rotating component within it to rotate. This rotating component can be a blade impeller, an annular blade impeller, etc., with a pre-installed mounting position. This mounting position can fix either the magnetic sensing device 1 or the magnetic field generating device 2, allowing the rotating component to drive either of them to rotate.
[0030] The magnetic sensing device 1 is the sensing component in this invention. It can sense the magnetic field and distinguish the polarity of the magnetic field. In an instrument metering device, the number of magnetic sensing devices 1 can be one or more. The more they are, the higher the resolution accuracy of the device. However, the corresponding data processing volume and economic cost will also increase. Therefore, in practical applications, it is necessary to find a balance between the number of devices.
[0031] The magnetic field generating device 2 is used to generate a magnetic field, and it includes at least one magnetic pole pair, which can be implemented in the form of a permanent magnet or an electromagnet. Each magnetic pole pair includes two opposing magnetic poles, namely the N pole and the S pole. It should be emphasized that the concept of "opposite" in the present invention does not mean that the N pole and the S pole are spatially opposite to each other along the center of a circle, but rather that their polarities are opposite. In fact, in some embodiments below, the two opposing magnetic poles of each magnetic pole pair are distributed adjacently at intervals, rather than spatially symmetrically.
[0032] Example 1
[0033] The device arrangement track 3 includes a first circular track 31 and a second circular track 32. Both tracks are circular because the distance between each arrangement point on the circumference of the circular track and the center is equal. This helps to reduce the distance between the magnetic sensing device 1 and the magnetic field generating device 2, thereby reducing the overall size of the device. Based on this, it can be known that there are two possible relative inner and outer distribution relationships between the magnetic sensing device 1 and the magnetic field generating device 2: one is that the magnetic sensing device 1 is arranged on the first circular track 31 (relatively inner), and the magnetic field generating device 2 is arranged on the second circular track 32 (relatively outer), as shown in Figure 1; the other is that the magnetic sensing device 1 is arranged on the second circular track 32 (relatively outer), and the magnetic field generating device 2 is arranged on the first circular track 31 (relatively inner), as shown in Figure 2. Since this invention uses the magnetic sensing device 1 to sense and identify the rotating magnetic field excited by the magnetic field generating device 2, the small distance between the two will not affect the accuracy of the judgment of the magnetic sensing device 1. It should be noted that the diameter of the first circular track 31 is smaller than that of the second circular track 32, which ensures that the second circular track 32 is always in the outer ring position. Furthermore, each of the two circular tracks naturally forms a track surface, which is usually spatially coincident, i.e., located in the same plane. However, in some special cases, the two track surfaces can also be coaxially parallel, as this does not affect the magnetic sensor 1's ability to identify different polarities. However, the distance between the two track surfaces should not be too large, as this may lead to a decrease in the sensing sensitivity of the magnetic sensor 1.
[0034] Example 2
[0035] The magnetic field generating device 2 contains n magnetic pole pairs, each containing two magnetic poles with opposite polarities, meaning the magnetic field generating device 2 contains 2n magnetic poles. Furthermore, the 2n magnetic poles are evenly and alternately distributed, dividing the track surface of the device arrangement track 3 into 2n sector-shaped magnetic pole induction areas. The central angle of each sector-shaped magnetic pole induction area is α = 360° / (2n). Since both tracks of the device arrangement track 3 are circular, under the premise of even alternation, each of the 2n magnetic poles provides a sector-shaped magnetic pole induction area with equal central angles, i.e., α = 360° / (2n). The 2n magnetic poles divide the track surface of the device arrangement track 3 into 2n sector-shaped magnetic pole induction areas. Specifically, the divided track surface can be either the track surface of the first circular track 31 or the track surface of the second circular track 32, depending on which circular track the magnetic field generating device 2 is arranged on.
[0036] Example 3
[0037] The track surface of the device arrangement track 3 is mapped with a reference positioning surface. The reference positioning surface is a spatial fixed positioning concept similar to a coordinate axis. Since in this invention, the rotating component always drives one of the magnetic sensing device 1 and the magnetic field generating device 2 to rotate, while the other remains stationary, a reference positioning surface is mapped to determine the spatial distribution position of the stationary component on one of the circular tracks of the device arrangement track 3. The reference positioning surface contains 2n primary positioning sectors. It can be seen that the number of primary positioning sectors is 2n, the same as the number of sector-shaped magnetic pole induction areas, and its central angle α' is the same as the central angle α of the sector-shaped magnetic pole induction areas. This makes each sector-shaped magnetic pole induction area similar in shape to each primary positioning sector. Furthermore, each primary positioning sector contains m secondary positioning sectors, where m is the number of magnetic sensing devices 1 arranged; the central angle of each secondary positioning sector is β = α' / m. It is important to note that each primary positioning sector contains m secondary positioning sectors, meaning that a single reference positioning surface contains a total of 2n·m secondary positioning sectors. Here, m represents the numerical number of magnetic sensing devices 1 arranged in a single instrument's measuring device.
[0038] Therefore, one of the circumferential directions of the reference positioning surface is selected as the positioning direction, and the m secondary positioning sectors contained in each primary positioning sector are sequentially marked as the first feature area to the mth feature area according to the positioning direction.
[0039] For example, in one possible reference positioning surface, there are four primary positioning sectors, and m=3 is set, meaning each primary positioning sector contains three secondary positioning sectors. The clockwise circumferential direction of the reference positioning surface is selected as the positioning direction. The three secondary positioning sectors contained in each primary positioning sector are sequentially labeled as first feature area β1 to third feature area β3. Then, three magnetically sensitive devices 1 are fixedly arranged in the feature areas and placed on the device arrangement track 3 (specifically, on the first circular track 31 or the second circular track 32). It is particularly important to note that the feature area labels for each magnetically sensitive device 1 are different. That is, the three magnetically sensitive devices 1 are respectively arranged in the first feature area s1, the second feature area s2, and the third feature area s3 of any four primary positioning sectors. For example, if a magnetic sensor 1 is already positioned in the first feature area s1 of one of the primary positioning sectors, then the other two magnetic sensors 1 cannot be positioned in the first feature area s1 of the remaining primary positioning sectors; they can only be positioned in the second feature area s2 or the third feature area s3. This is to ensure that at least one magnetic sensor can acquire a detection signal when the sector-shaped magnetic pole induction area rotates relative to the magnetic sensor by any unit degree, thereby obtaining continuous, complete, and accurate measurement data. One unit degree is numerically equal to the central angle β of the secondary positioning sector. Therefore, the more magnetic sensors 1 are arranged, the smaller the central angle β of the secondary positioning sector, the smaller the value of one unit degree, the higher the measurement accuracy, and the greater the data processing volume.
[0040] Example 4
[0041] The magnetic sensing devices 1, which are fixedly arranged in each secondary positioning sector, are all located on the sector center line of that secondary positioning sector. This arrangement ensures that the angle between the centers of the circles formed by each magnetic sensing device 1 is an integer multiple of one unit degree, making subsequent calculations more convenient and improving calculation accuracy.
[0042] Example 5
[0043] As shown in Figure 2, three magnetic sensing devices 1 are selected, and the magnetic field generating device 2 includes a magnetic pole pair. The two opposing magnetic poles in the magnetic pole pair are spatially distributed, dividing the track surface of the device arrangement track 3 into two sector-shaped magnetic pole induction areas. The central angle of each sector-shaped magnetic pole induction area is α = 180°. At the same time, the reference positioning surface includes two primary positioning sectors, each with a central angle α' = 90°. Each primary positioning sector contains three secondary positioning sectors in the clockwise positioning direction. The unit degree is the same as the central angle β of the secondary positioning sector, which is 60°. Furthermore, the magnetic sensing device A is arranged in the upper half of the primary positioning sector in Figure 2. On the center line of the sector of the second feature area s2 in the region, the magnetic sensitive device B is arranged on the center line of the sector of the first feature area s1 in the lower half of the primary positioning sector, and the magnetic sensitive device C is arranged on the center line of the sector of the third feature area s3 in the lower half of the primary positioning sector in Figure 2. Thus, the feature area markings of each magnetic sensitive device 1 are different, and the angle between the centers of the circles formed by each magnetic sensitive device 1 is twice a unit degree, i.e., 120°. Furthermore, all three magnetic sensitive devices 1 fall on the upper second circular track 32 and are fixed in position. In this embodiment, the rotating component is fixedly connected to the magnetic field generating device 2, driving one of the magnetic pole pairs in the magnetic field generating device 2 to rotate on the first circular track 31.
[0044] Let A, B, and C represent three magnetic sensing devices 1. Each magnetic sensing device 1 uses a high level 1 to indicate that it senses the relative magnetic pole N and a low level 0 to indicate that it senses the S pole. In any rotation cycle of the magnetic field generating device 2, the three magnetic sensing devices 1 generate a total of six detection signals, which correspond to six states. The truth table for each state can be shown in Table 1 below. In this table, the switching of two adjacent states once represents that the volume of the measured fluid has increased by one unit of measurement V.
[0045] When the magnetic field generating device 2 rotates, the rotating magnetic field will produce different excitation effects on the three magnetic sensitive devices 1. Assuming that the rotation is clockwise and each rotation is 60°, the state changes in the following order: state 1, state 2... state 5, state 6. When the rotation is counterclockwise, the state changes in the following order: state 6, state 5... state 2, state 1.
[0046] Table 1. Status Statistics of Magnetically Sensitive Devices A, B, and C
[0047]
[0048] Example 6
[0049] The difference from Example 5 is that the number of magnetic sensing devices 1 is reduced to two, with A and C representing the two magnetic sensing devices 1 respectively. This example can simulate the scenario in Example 1 where magnetic sensing device B 1 fails, and the remaining two magnetic sensing devices 1 can still maintain normal measurement function. Ignoring magnetic sensing device B, the corresponding state statistics table is shown in Table 2 below. Unlike Table 1, states 1 and 6 have the same state result, and states 3 and 4 have the same state result. The fluid volume increase corresponding to both state results is 2V; while the fluid volume increase corresponding to states 2 and 5 is still V (unchanged compared to Table 1), thus maintaining accurate measurement.
[0050] Table 2. Status Statistics of Magnetically Sensitive Devices A and C
[0051]
[0052] Example 7
[0053] As shown in Figure 3, the difference from Embodiment 6 is that there are two magnetic sensing devices 1, and the magnetic field generating device 2 contains two magnetic pole pairs. The four opposing magnetic poles are evenly and alternately distributed in space, dividing the track surface of the device arrangement track 3 into four sector-shaped magnetic pole induction areas. The central angle of each sector-shaped magnetic pole induction area is α=90°. At the same time, the reference positioning surface contains four primary positioning sectors, and the central angle of each primary positioning sector is α`=90°. Each primary positioning sector contains two secondary positioning sectors in the clockwise positioning direction. The central angle β of one unit degree is the same as that of the secondary positioning sector, which is 45°. Furthermore, magnetic sensing device A is arranged on the center line of the second feature area s2 of one of the primary positioning sectors in Figure 3, and magnetic sensing device B is arranged on the center line of the first feature area s1 of another primary positioning sector. Thus, the angle between the centers of magnetic sensing devices A and B is twice that of one unit degree, which is 45°.
[0054] Example 8
[0055] As shown in Figure 4, the difference from the above implementation is that the magnetic sensing device 1 is arranged on the upper first circular track 31 and fixed in position. In this implementation, the rotating component is fixedly connected to the magnetic field generating device 2, driving the two magnetic pole pairs in the magnetic field generating device 2 to rotate on the second circular track 32. In this embodiment, the two magnetic pole pairs of the magnetic field generating device 2 are arranged in a ring shape on the outer ring track, and the magnetic sensing device 1 is fixedly arranged on the inner ring track. Four opposing magnetic poles are evenly and alternately distributed in space, dividing the track surface of device arrangement track 3 into four sector-shaped magnetic pole induction areas. The central angle of each sector-shaped magnetic pole induction area is α=90°. At the same time, the reference positioning surface contains four primary positioning sectors, and the central angle of each primary positioning sector is α`=90°. Each primary positioning sector contains two secondary positioning sectors in the clockwise positioning direction. And one unit degree is the same as the central angle β of the secondary positioning sector, which is 45°. Magnetic sensitive device A is arranged on the center line of the second feature area s2 of one of the primary positioning sectors in Figure 4, and magnetic sensitive device B is arranged on the center line of the first feature area s1 of another primary positioning sector. The angle between the centers of magnetic sensitive devices A and B is three times one unit degree (45°), that is, 135°.
[0056] In the above-described implementations, the rotating component is fixedly connected to the magnetic field generating device 2, driving the magnetic field generating device 2 to rotate on the first circular track 31 or the second circular track 32. In addition, it should be noted that, based on the claims of this invention, the rotating component can also be fixedly connected to the magnetic sensitive device 1, driving the magnetic sensitive device 1 to rotate on the first circular track 31 or the second circular track 32. In this case, the relevant distribution rules regarding the magnetic sensitive device 1 still apply, because the magnetic sensitive device 1 and the magnetic field generating device 2 are always rotating relative to each other. Here, it can still be considered that the position of the magnetic sensitive device 1 is fixed, while the magnetic field generating device 2 rotates relative to it. Whether the rotating component is specifically fixedly connected to the magnetic sensitive device 1 or the magnetic field generating device 2 is determined based on the actual product's spatial arrangement requirements, hardware parameter configuration, and production material model, all of which are applicable to the technical solution provided by this invention.
[0057] It is important to note that in this invention, both the magnetic sensing device 1 and the magnetic field generating device 2 are wrapped with a magnetic shielding layer on their outer sides. This magnetic shielding layer is used to resist external magnetic interference. A magnetic shielding layer is a layered structure used to reduce or prevent interference from external magnetic fields on equipment or devices, and is typically made of a material with high magnetic permeability. Common types of magnetic shielding layers include, for example, metallic shielding layers made of ferromagnetic materials such as soft iron, silicon steel, and permalloy, or gas shielding layers formed by surrounding the device with gaseous materials such as nitrogen or argon.
[0058] It should also be noted that this type of metering device also includes a processor electrically connected to all magnetic sensing devices, used to collect and measure the detection signals sent by the magnetic sensing devices. The processor can be implemented using a microcontroller or MCU, used to collect and measure the detection signals sent by the magnetic sensing devices to calculate the flow rate of the measured gas or water.
[0059] The above description is merely a preferred embodiment disclosed in this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of protection involved in this disclosure is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-disclosed concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this disclosure.
[0060] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.
[0061] The foregoing description is merely an exemplary embodiment of this disclosure and should not be construed as limiting the scope of this disclosure. Any equivalent changes and modifications made in accordance with the teachings of this disclosure shall still fall within the scope of this disclosure. Those skilled in the art will readily conceive of embodiments of this disclosure upon considering the specification and practicing the disclosure herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not described herein. The specification and embodiments are to be considered exemplary only, and the scope and spirit of this disclosure are defined by the claims.
Claims
1. An instrument metering device based on magnetic field polarity sensing, comprising a rotating component driven by a fluid, a magnetic sensitive device (1), and a magnetic field generating device (2), characterized in that, The rotating component is connected to the magnetic sensitive device (1) or the magnetic field generating device (2) and drives the magnetic sensitive device (1) or the magnetic field generating device (2) to rotate on the device arrangement track (3); the magnetic field generating device (2) includes at least one magnetic pole pair.
2. The instrument metering device based on magnetic field polarity sensing according to claim 1, characterized in that, The device arrangement track (3) includes a first circular track (31) and a second circular track (32); the diameter of the first circular track (31) is smaller than the diameter of the second circular track (32).
3. The instrument metering device based on magnetic field polarity sensing according to claim 2, characterized in that, The magnetic field generating device (2) contains n magnetic pole pairs, each of which contains two magnetic poles with opposite polarities.
4. A metering device based on magnetic field polarity sensing according to claim 3, characterized in that, The magnetic field generating device (2) has 2n magnetic poles that are evenly and alternately distributed, dividing the track surface of the device arrangement track (3) into 2n sector-shaped magnetic pole induction areas, with the central angle of each sector-shaped magnetic pole induction area being α=360° / (2n).
5. A metering device based on magnetic field polarity sensing according to claim 4, characterized in that, The track surface of the device arrangement track (3) is mapped with a reference positioning surface, and the reference positioning surface contains 2n primary positioning sectors; the central angle α` of the primary positioning sector is the same as the central angle α of the sector magnetic pole induction area; each primary positioning sector contains m secondary positioning sectors, where m is the number of magnetic sensitive devices (1) arranged; the central angle of each secondary positioning sector is β=α` / m.
6. The instrument metering device based on magnetic field polarity sensing according to claim 5, characterized in that, Select one of the circumferential directions of the reference positioning surface as the positioning direction, and mark the m secondary positioning sectors contained in each primary positioning sector as the first feature area to the mth feature area according to the positioning direction; m magnetic sensing devices (1) are fixedly arranged in the feature area and fall on the device arrangement track (3); the feature area marking numbers of each magnetic sensing device (1) are different.
7. The instrument metering device based on magnetic field polarity sensing according to claim 6, characterized in that, The rotating component is connected to the magnetic field generating device (2) and drives the magnetic field generating device (2) to rotate on the second circular track (32); the magnetic field generating device (2) includes two magnetic pole pairs, dividing the track surface of the device arrangement track (3) into four sector magnetic pole induction areas, and the central angle of each sector magnetic pole induction area is α=90°; two magnetic sensitive devices (1) are fixedly arranged on the first circular track (31), and the two magnetic sensitive devices (1) are located in two secondary positioning sectors with different feature area marking numbers.
8. The instrument metering device based on magnetic field polarity sensing according to claim 6, characterized in that, The magnetic sensitive device (1) fixedly arranged in each of the secondary positioning sectors is located on the sector center line of the secondary positioning sector.
9. A metering device based on magnetic field polarity sensing according to claim 1, characterized in that, The magnetic sensing device (1) and the magnetic field generating device (2) are wrapped with a shielding layer on the outside, which is used to resist external magnetic interference.
10. A metering device based on magnetic field polarity sensing according to any one of claims 1-9, characterized in that, The instrument measurement device also includes a processor electrically connected to all of the magnetic sensing devices (1) for collecting the detection signals sent by the magnetic sensing devices (1) and performing measurement.