A method for electromechanical conversion of intelligent water meter

Abstract

The present invention discloses an electromechanical conversion method for an intelligent water meter. The device used in the method includes a housing, a rotating shaft rotatably connected to the housing, an impeller connected to the circumference of the rotating shaft, a rotating shaft extending outside the housing fixed with a magnetic steel seat, a magnetic steel symmetrically fixed on the magnetic steel seat, a tunnel magnetoresistive sensor board fixed on the housing, and two tunnel magnetoresistive sensors installed on the tunnel magnetoresistive sensor board. The polarities of the two magnetic steels are opposite, and the sensitive axes of the two tunnel magnetoresistive sensors are perpendicular to each other. The method records the change in the direction of the magnetic field generated by the magnetic steel seat caused by the rotation of the impeller, and calculates the instantaneous rate of the impeller rotation by #imgabs0# where k'=1 / k is a constant. Compared with the prior art, with the support of the present method, the instantaneous speed of the impeller's deflection angle at the current moment can be accurately calculated, the metering resolution of the water meter can be improved, the instantaneous flow rate at any moment can be measured, and the accuracy of the instantaneous flow rate measurement can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of water meter measurement, and in particular to an electromechanical conversion method for an intelligent water meter. Background Art

[0002] Smart water services are an important part of smart city construction, and smart water meters are important basic equipment for realizing smart water services. Existing small-caliber smart water meters can be roughly divided into electromechanical conversion type and ultrasonic type according to the measurement principle. The electromechanical conversion type uses a mechanical structure (usually an impeller, turbine, etc.) and a tunnel magnetoresistive sensor (reed switch, magnetoresistive, Hall, etc.) to convert the water flow signal into a switch signal, and then measure it by counting the switch signal. The ultrasonic type measures the cumulative water volume by fitting the flow curve at discrete instantaneous flow points.

[0003] Although ultrasonic smart water meters can directly obtain instantaneous flow information, they use discrete instantaneous flow points to fit the actual flow curve, resulting in weak flow-following performance. In situations where the flow changes greatly, large water volume errors will occur, especially when some water meters blindly reduce the sampling frequency to reduce power consumption, resulting in greater measurement errors. At the same time, small-caliber ultrasonic smart water meters basically rely on propagation time difference for measurement. When the clock chip temperature drifts, the probe position changes, or foreign matter is attached to the probe, it will directly lead to serious measurement deviations. Therefore, in order to ensure the accuracy of measurement, necessary maintenance of ultrasonic water meters is usually required, but the base of small-caliber smart water meters is huge, making it difficult to perform effective maintenance.

[0004] Most of the existing small-diameter smart water meters use electromechanical conversion, and measure the water meter by measuring the number of revolutions of the water meter impeller (i.e., "counting pulses"), that is, one revolution is one pulse (usually 0.1L). The measurement principle results in a low measurement resolution and is unable to measure the instantaneous flow at a certain moment, that is, the accuracy of the instantaneous flow is not high. Summary of the invention

[0005] The purpose of the present invention is to design an electromechanical conversion method for a smart water meter to solve the problems raised in the above background technology.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a method for electromechanical conversion of a smart water meter, wherein the device used in the method comprises a housing, a rotating shaft rotatably connected to the housing, an impeller connected to the circumference of the rotating shaft, a magnetic steel seat fixed to the rotating shaft extending outside the housing, magnetic steel symmetrically fixed to the magnetic steel seat, a tunnel magnetoresistive sensor board fixed to the housing, and two tunnel magnetoresistive sensors mounted on the tunnel magnetoresistive sensor board. It is characterized in that: the polarities of the two magnetic steels are opposite, the sensitive axes of the two tunnel magnetoresistive sensors are perpendicular to each other, and the steps of the method are as follows:

[0007] S1. Continuously record the output signal value B of the tunnel magnetoresistance sensor S1 , B S2

[0008] S2, calculate the impeller rotation angle α according to the theoretical value of S1: Wherein B is the magnetic field intensity corresponding to the sensing plane of the tunnel magnetoresistive sensor;

[0009] S3. The impeller rotation speed is proportional to the water flow rate through the water meter, that is: ω = k·Q, Among them, ω is the impeller rotation angular velocity, that is, the magnetic field rotation angular velocity, t is time, Q is the water flow rate flowing through the water meter, k is a constant, and k'=1 / k is a constant.

[0010] Furthermore, in order to retain the advantages of continuous metering, each complete cycle represents a fixed water volume V0, and the cumulative water volume is: Where n represents the number of cycles of impeller rotation.

[0011] Beneficial effects of the present invention: Compared with the prior art, since the electromechanical conversion method of the smart water meter of the present invention records the magnetic field direction change curve caused by the impeller magnetic steel conversion structure through two tunnel magnetoresistive sensors, the instantaneous speed of the impeller's deflection angle at the current moment can be accurately calculated, the metering resolution of the water meter can be improved, the instantaneous flow rate at any moment can be measured, and the accuracy of instantaneous flow rate measurement can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0013] Figure 1 A schematic diagram of the structure of the device used in the electromechanical conversion method of the smart water meter of the present invention;

[0014] Figure 2 It is a working schematic diagram of the measuring method of the present invention;

[0015] Figure 3 is a schematic diagram of the states of the sensing signals of the first tunnel magnetoresistive sensor and the second tunnel magnetoresistive sensor;

[0016] The names of the components marked in the figure are as follows: 1. Shell; 2. Impeller; 3. Rotating shaft; 4. Magnetic steel seat; 5. First tunnel magnetoresistance sensor; 6. Tunnel magnetoresistance sensor board; 8. Second tunnel magnetoresistance sensor; 9. Magnetic steel. DETAILED DESCRIPTION

[0017] The following will be combined with the accompanying drawings in the present invention to clearly and completely describe the technical solution in the present invention. Obviously, what is described is only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0018] Reference Figure 1-2 The electromechanical conversion method of the smart water meter of the present invention, the device used in the method includes a housing 1, a rotating shaft 3 rotatably connected to the housing 1, an impeller 2 connected to the peripheral side of the rotating shaft 3, a magnetic steel seat 4 fixed to the rotating shaft 3 extending outside the housing 1, a magnetic steel 9 symmetrically fixed to the magnetic steel seat 4, a tunnel magnetoresistive sensor board 6 fixed to the housing 1, and a first tunnel magnetoresistive sensor 5 and a second tunnel magnetoresistive sensor 8 installed on the tunnel magnetoresistive sensor board 6. The two magnetic steels 9 are permanent magnets with opposite polarities, the two tunnel magnetoresistive sensors are perpendicular to each other, an XY coordinate system is established with the intersection of the two sensor sensing ends, and the magnetic field direction angle between the second tunnel magnetoresistive sensor 8 and the coordinate system plane is set as α, and the steps of the method are as follows:

[0019] S1, continuously record the output signal value B of the tunnel magnetoresistance sensor S1 , B S2 :B S1 =B·sinα、B S2 =B·cosα, where B is the magnetic field intensity corresponding to the sensing plane of the tunnel magnetoresistive sensor, which is a constant value. As the impeller drives the shaft to rotate, the magnetic steel seat rotates, thereby causing the magnetic field direction to rotate, that is, α changes between (0°, 360°). The corresponding B measured by the first tunnel magnetoresistive sensor 5 and the second tunnel magnetoresistive sensor 8 S1 , B S2 Data such as Figure 3 As shown;

[0020] S2. Calculate the impeller rotation angle α, i.e. the angle between the magnetic field direction and the second tunnel magnetoresistive sensor, based on the theoretical value of S1:

[0021] S3. The impeller rotation speed is proportional to the water flow rate through the water meter, that is: ω = k·Q,

[0022] Therefore Among them, ω is the impeller rotation angular velocity, that is, the magnetic field rotation angular velocity, t is time, Q is the water flow rate flowing through the water meter, k is a constant, and k'=1 / k is a constant. , is the rate of change of magnetic field components. The corresponding relationship can be expressed by applying linear regression through multi-point sampling, which is convenient for calculation.

[0023] In an optional embodiment, in order to retain the advantages of continuous metering, each complete cycle represents a fixed water volume V0, and the accumulated water volume is: Among them, n represents the number of cycles, that is, the integer number of revolutions of the impeller.

[0024] In summary, by applying this structure and method, the instantaneous flow velocity when the impeller rotates to a specific angle can be accurately measured, thereby improving the metering resolution of the water meter. At the same time, the accumulated water volume can be accurately calculated based on this principle.

[0025] The above is a specific description of the preferred implementation of the present invention, but the present invention is not limited to the described embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A method for electromechanical conversion of a smart water meter, wherein the device used in the method comprises a housing (1), a rotating shaft (3) rotatably connected to the housing (1), an impeller (2) connected to the circumference of the rotating shaft (3), a magnetic steel seat (4) fixed to the rotating shaft (3) extending outside the housing (1), a magnetic steel (9) symmetrically fixed to the magnetic steel seat (4), a tunnel magnetoresistive sensor plate (6) fixed to the housing (1), and two tunnel magnetoresistive sensors mounted on the tunnel magnetoresistive sensor plate (6), characterized in that: The polarities of the two magnetic steels are opposite, and the sensitive axes of the two tunnel magnetoresistive sensors are perpendicular to each other. The steps of the method are as follows: S1. Continuously record the output signal value B of the tunnel magnetoresistance sensor S1 , B S2 ; S2, calculate the impeller rotation angle α according to the theoretical value of S1: Wherein B is the magnetic field intensity corresponding to the sensing plane of the tunnel magnetoresistive sensor; S3, the impeller rotation speed is proportional to the water flow rate through the water meter, ω = k·Q, Among them, ω is the impeller rotation angular velocity, that is, the magnetic field rotation angular velocity, t is time, Q is the water flow rate flowing through the water meter, k is a constant, and k'=1 / k is a constant.

2. The electromechanical conversion method of the smart water meter according to claim 1, characterized in that: In order to retain the advantages of continuous metering, the fixed water volume for each complete cycle is V0, and the cumulative water volume is: Where n represents the number of cycles of impeller rotation.

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