Wireless transmission compensation pressure type water gauge with wave reduction structure

Abstract

The utility model provides a wireless transmission compensation pressure type water gauge with a wave reduction structure, which comprises a cylindrical main body, the cylindrical main body is provided with a mounting surface, and the plane of the mounting surface is vertical to the central axis of the cylindrical main body; the mounting surface is used for mounting a pressure sensor; a water inlet is formed in the bottom of the cylindrical main body; a first grid wave reduction structure and a second grid wave reduction structure are also arranged on the cylindrical main body; the first grid wave reduction structure and the second grid wave reduction structure are sequentially arranged in the water flow direction. The first grid wave reduction structure and the second grid wave reduction structure are each provided with a plurality of wave reduction teeth. The arrangement directions of the wave reduction teeth of the first grid wave reduction structure and the second grid wave reduction structure are perpendicular to each other; by applying the technical scheme, the influence of the water flow speed, the water flow acceleration and the water surge on the measurement precision of the pressure type water gauge can be reduced.

Description

Technical Field

[0001] This utility model relates to the field of sensing and control technology, and in particular to a wireless transmission compensation pressure gauge with a wave reduction structure. Background Technology

[0002] A pressure gauge is a device that measures the hydrostatic pressure at a certain depth using a pressure sensor and calculates the water depth. It measures the hydrostatic pressure at a specific location and uses the formula P = ρgh (where ρ is the density of water, g is the acceleration due to gravity, and h is the water depth) to obtain the water depth h at that location. Pressure gauges are often installed in rivers, lakes, and seas. The water in these places is not ideally static; rivers often have fixed flow directions, and oceans are prone to waves. The movement of water carries additional acceleration, i.e.

[0003] The pressure exerted by the water on the surface of the pressure sensor = hydrostatic pressure + additional pressure from water movement.

[0004] This will pose a challenge to the accurate measurement of pressure gauges. Utility Model Content

[0005] In view of this, the purpose of this utility model is to provide a wireless transmission compensation pressure gauge with a wave reduction structure to reduce the impact of water flow velocity, water flow acceleration, and water surge on the measurement accuracy of the pressure gauge.

[0006] To achieve the above objectives, this utility model adopts the following technical solution: a wireless transmission compensated pressure gauge with a wave-damping structure, comprising a cylindrical body, wherein the cylindrical body is provided with a mounting surface, the plane of which is perpendicular to the central axis of the cylindrical body; the mounting surface is used to mount a pressure sensor; the bottom of the cylindrical body is a water inlet; the cylindrical body is also provided with a first grid wave-damping structure and a second grid wave-damping structure; the first grid wave-damping structure and the second grid wave-damping structure are arranged sequentially along the water flow direction; both the first grid wave-damping structure and the second grid wave-damping structure are provided with multiple wave-damping teeth. The wave-damping teeth of the first grid wave-damping structure and the second grid wave-damping structure are arranged perpendicularly to each other.

[0007] In a preferred embodiment, the first grid anti-wave structure is formed by a plurality of first anti-wave teeth arranged in parallel to each other to form a first anti-wave mesh; the second grid anti-wave structure is formed by a plurality of second anti-wave teeth arranged in parallel to each other to form a second anti-wave mesh.

[0008] In a preferred embodiment, the plane containing the first and second wave-damping meshes is perpendicular to the central axis of the cylindrical body.

[0009] In a preferred embodiment, the width of the first and second wave-damping teeth along the cross section perpendicular to their length direction gradually increases along the water flow direction.

[0010] In a preferred embodiment, the first and second anti-wave teeth are trapezoidal in cross-section along their length direction.

[0011] In a preferred embodiment, the cross-section of the cylindrical body along the vertical central axis is composed of a circular arc and a line segment connecting the beginning and end.

[0012] Compared with the prior art, the present invention has the following beneficial effects: reducing the impact of water flow velocity, water flow acceleration, and water surge on the accuracy of pressure gauge measurements. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the basic structure of the water gauge according to a preferred embodiment of the present invention;

[0014] Figure 2 This is a cross-sectional view of the cylinder intersecting the plane in a preferred embodiment of the present invention;

[0015] Figure 3 This is a schematic diagram of the intersection of the cylinder and the plane in a preferred embodiment of the present invention;

[0016] Figure 4 This is a structural diagram of a single-layer grid-type anti-wave mesh according to a preferred embodiment of the present invention;

[0017] Figure 5 This is a schematic diagram of the wedge-shaped structure of the grid anti-wave mesh in a preferred embodiment of the present invention;

[0018] Figure 6 This is a schematic diagram of the longitudinal section of the triangular wedge-shaped anti-wave tooth structure of the preferred embodiment of this utility model;

[0019] Figure 7 This is a schematic diagram of the trapezoidal wedge-shaped wave-reducing tooth structure in the longitudinal section of a preferred embodiment of the present invention;

[0020] Figure 8 This is a side view of the double-layer grid-type anti-wave mesh structure of a preferred embodiment of the present invention;

[0021] Figure 9 This is a bottom view of the double-layer grid-type anti-wave mesh structure of a preferred embodiment of the present invention;

[0022] Figure 10 The anti-wave tooth structure parameters of the wedge-shaped grid anti-wave mesh in the preferred embodiment of this utility model;

[0023] Figure 11 The trend graph of function value of formula (2) in the preferred embodiment of this utility model;

[0024] Figure 12 This is a schematic diagram of the terminal connection of a preferred embodiment of the present invention;

[0025] Figure 13 The sensing output curve of the pressure sensor in a preferred embodiment of this utility model;

[0026] Figure 14 This is a structural diagram of a preferred embodiment of the present invention with multiple pressure sensors. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0028] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0029] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations according to this application; as used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise; furthermore, it should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0030] Wireless transmission compensated pressure gauge with wave reduction structure, reference Figure 1-14 The device includes a cylindrical body with a mounting surface 3, the plane of which is perpendicular to the central axis of the cylindrical body. The mounting surface is used to mount a pressure sensor. The bottom of the cylindrical body is a water inlet. The cylindrical body also has a first grid wave-damping structure 1 and a second grid wave-damping structure 2. The first grid wave-damping structure 1 and the second grid wave-damping structure 2 are arranged sequentially along the water flow direction. Both the first grid wave-damping structure 1 and the second grid wave-damping structure 2 have multiple wave-damping teeth. The wave-damping teeth 2 of the first grid wave-damping structure 1 and the second grid wave-damping structure are arranged perpendicularly to each other.

[0031] The first grid wave-reducing structure consists of multiple first wave-reducing teeth arranged in parallel to each other to form a first wave-reducing net; the second grid wave-reducing structure consists of multiple second wave-reducing teeth arranged in parallel to each other to form a second wave-reducing net. Specifically, the planes containing the first and second wave-reducing nets are perpendicular to the central axis of the cylindrical body. The width of the cross-sections of the first and second wave-reducing teeth along their length direction gradually increases along the water flow direction. Specifically, the cross-sections of the first and second wave-reducing teeth along their length direction are trapezoidal.

[0032] Specifically, the cross-section of the cylindrical body along the vertical central axis consists of a circular arc and a line segment connecting the beginning and end.

[0033] Because river water flows from high to low, the water may have acceleration. This acceleration exerts a force on the pressure sensing surface of the pressure gauge, causing an increase in measured pressure and correspondingly an increase in measured depth. However, this increase is actually an error. Therefore, the inlet of this pressure gauge is located at the bottom of the gauge body. This avoids interference from laterally flowing water on water depth measurement.

[0034] To further reduce the impact of undercurrents or currents entering the water flow through the bottom inlet on the installation... Figure 1 To mitigate the influence of the pressure sensor at mounting surface 3, this invention employs two layers of mutually perpendicular wedge-shaped grid-type anti-reflective mesh. The structure of a single-layer grid-type anti-reflective mesh is as follows: Figure 4 As shown, the wave-damping mesh is composed of rows of wedge-shaped wave-damping teeth, and the structure of the wave-damping teeth is shown in the diagram. Figure 5 As shown, it forms a wedge shape, wider at the bottom and narrower at the top. The longitudinal section structure of the anti-wave tooth can be triangular or trapezoidal, and can present different individual and combined forms, such as... Figure 6 and Figure 7 As shown.

[0035] In practical use, this utility model adopts a two-layer grid-type anti-wave mesh structure with the upper and lower layers stacked, and the anti-wave teeth are arranged in a mutually perpendicular shape. Figure 8 and Figure 9 These are its side view and bottom view, respectively. From Figure 9 As can be seen from the upward angle, the water flows through two layers of wave-damping grids, and the flow holes are rectangular in shape.

[0036] To enable those skilled in the art to understand the method of using this utility model, the method of using this utility model is described below:

[0037] Algorithm for the wave-reducing tooth structure parameters of wedge-shaped grid wave-reducing mesh. There are 6 parameters involved in the wave-reducing teeth: tooth root width S1, tooth tip width S2, tooth height hs, tooth spacing Ms, tooth pattern coefficient st, and tooth arrangement coefficient q.

[0038] To design the structure of wave-damping teeth, we first need to define a grid wave-damping value γ. This value indicates the degree to which the wave-damping teeth and the wave-damping mesh structure they form attenuate water flow and waves. The larger the grid wave-damping value γ, the more obvious the grid wave-damping effect, but at the same time, the slower the pressure sensor refresh effect is affected by changes in water depth.

[0039]

[0040] Where st is the tooth pattern coefficient, q is the tooth arrangement coefficient, ω is the wave reduction adjustment coefficient, A is the wave reduction influence value, which is calculated by equation (2); hs is the tooth height, and Ms is the tooth center distance.

[0041]

[0042] Where g = S1 - S2, Figure 11 The trend line of the function in formula (2) is such that the larger the value of g, the larger the value of γ, and the better the wave reduction effect; μ and σ are the function adjustment parameters, which act on... Figure 11 The style coefficient st of the tooth is shown in the image. Figure 6 As shown in (1), (2), and (3), the isosceles triangle in the longitudinal section has a better wave reduction effect than the right triangle. The st value for the isosceles triangle can be taken as 1.2, and the st value for the right triangle as 1.0. The specific values ​​should be confirmed by the user through experiments. The tooth arrangement coefficient q is as follows: Figure 6 As shown in (4) and (5), the wave reduction effect of the opposing arrangement is better than that of the parallel arrangement. The q value of the opposing arrangement can be 1.2, and the q value of the parallel arrangement can be 1.0.

[0043] like Figure 1 As shown, besides the toothed structure of the grid, the beam reduction effect of the beam reduction grid is also affected by the beam reduction mesh spacing H1 and the distance H2 between the beam reduction mesh and the sensor mounting surface. Therefore, the system Ф is determined by the following formula:

[0044]

[0045] Where a and b are the set values ​​for the spacing between the anti-reflection mesh and the distance between the anti-reflection mesh and the sensor mounting surface, respectively, which are determined by the engineer through preliminary experiments, and λ is the adjustment coefficient, which is determined by the actual situation.

[0046] The tuning steps are as follows:

[0047] Step 1: Based on the average annual flow velocity, water density, and impurity level of the water body (river), determine Ф using equation (3) through theoretical derivation, experiments, and analysis.

[0048] Step 2: Reverse derive equation (1)γ from Ф

[0049] Step 3: Calculate the parameters on the right side of γ.

[0050] The parameters were determined through theoretical derivation, field experiments, and specific analysis.

[0051] The principle of a pressure gauge is to measure the pressure P by measuring the pressure exerted by water on the diaphragm of a single pressure sensor (not a differential pressure sensor) at the water level. The water depth h at that location is then calculated using the formula P = ρgh (where ρ is the density of water, g is the acceleration due to gravity, and h is the water depth). Therefore, the atmospheric pressure superimposed on the water pressure will affect the actual measured P value, so it needs to be subtracted. Additionally, the temperature of the water itself will affect the water density ρ, so the water temperature must also be measured.

[0052] like Figure 12 As shown, the terminal device of this utility model consists of two parts:

[0053] A water gauge measures water level pressure (for determining water depth h) and water temperature (for obtaining water density ρ). This data is then wirelessly transmitted via a communication chip supporting the LoRa protocol to a receiver on the shore. The receiver, in addition to receiving data from the water gauge, also measures atmospheric pressure, temperature, and humidity. The atmospheric temperature and humidity are used to calibrate the atmospheric pressure value. Subtracting the atmospheric pressure value from the water level pressure value obtained from the water gauge yields the actual pressure value. The water depth at the location of the water level pressure sensor can then be calculated using the formula P = ρgh (where ρ is the density of water, g is the acceleration due to gravity, and h is the water depth). Finally, combining this with the water gauge's elevation and length information, the water depth at that location can be further determined.

[0054] The sampling compensation mechanism of this innovation can improve the measurement accuracy of the pressure gauge.

[0055] like Figure 13 As shown, the output curve of a pressure sensor is not necessarily a straight line, but often exhibits an upward curve shape, meaning the output voltage increases with increasing pressure, but it is not on a straight line. Therefore, a straight line segment connecting two points on the curve can be used to approximate the output relationship of this segment of the curve in a local area (similar to the red-marked line segments ab and bc) to obtain a relatively accurate measurement value. Users are often not familiar with the output curve of the pressure sensor, and the curve may also deviate from the actual measurement due to changes in the complex external environment. Therefore, it is necessary to perform piecewise linear approximation manual calibration of the equipment before use. This involves manually measuring the output voltage at several points at different water depths, using the pressure value estimated by the formula as the abscissa, and the actual voltage output value of the sensor as the ordinate, to perform curve fitting and obtain the corresponding curve.

[0056] However, this requires manual calibration of each sensor for use in different scenarios, which is tedious, labor-intensive, inconvenient, and significantly increases deployment costs. This invention proposes a small-segment underwater self-calibration error compensation mechanism. Figure 14 As shown, the number of sensors is increased, with more than two sensors arranged along the extension of the water gauge. Figure 14 Taking three points as an example, at positions a, b, and c respectively, the straight-line distance between a and b is s1, and the straight-line distance between b and c is s2; x1, x2, and x3 are the x-coordinates of a, b, and c, and the projection values ​​of the three points a, b, and c onto the x-axis, respectively. The intervals s1 and s2 can be equal or unequal. By measuring the pressure values ​​p1, p2, and p3 at points a, b, and c respectively, three point pairs (x1, p1), (x2, p2), and (x3, p3) can be formed. Using the analytical geometry formula for finding a straight line from two points, line segment 1 determined by (x1, p1) and (x2, p2) and line segment 2 determined by (x2, p2) and (x3, p3) can be obtained. In this way, the region from a to c can be divided into two regions according to a->b and b->c, and different straight-line slopes can be used for calculation, thereby approximating the original output curve and reducing the error.

[0057] The advantages of this process are: first, it allows for automatic calibration via equipment without manual intervention; second, it reduces the error of directly fitting a straight line using the two endpoints (by using segmentation to determine the slope).

[0058] Pressure gauges are typically installed in reservoirs or rivers. Normally, their electronic systems rely solely on battery power, which is difficult to replenish. Therefore, low power consumption and energy-saving mechanisms are crucial considerations. Sometimes, when river water levels change slowly, the water pressure sampling interval and wireless communication interval can be gradually increased; conversely, when water levels change rapidly, these intervals need to be shortened. Since the power consumption from sensor sampling and wireless communication constitutes a major portion of the system's power, while the microcontroller's standby power consumption is very small, adopting a mechanism that adaptively adjusts the sampling and transmission intervals based on the water pressure change rate can significantly reduce overall system power consumption, extend the equipment's lifespan when only a single battery is installed without additional power, and improve the equipment's overall lifespan.

[0059] This method uses the differential value dp / dt (i.e., the slope of the tangent line at that point in the water pressure change curve) of the recorded water pressure change curve to determine the size of the interval. The calculation formula is shown below:

[0060]

[0061] Where T is the sampling and transmission interval, λ is adjustment parameter 1, and α is adjustment parameter 2, both specified by the engineer according to the actual situation; dp / dt is the water pressure change rate. As the change rate increases, it indicates that the external water level is changing rapidly, requiring timely feedback. To prevent missed reports or loss of timeliness, the sampling interval must be shortened. As the change rate decreases, it indicates that the external water level is changing more slowly, and the sampling interval can be increased to save valuable energy.

Claims

1. A wireless transmission compensated pressure gauge with a wave reduction structure, characterized in that, The device includes a cylindrical body with a mounting surface perpendicular to its central axis. The mounting surface is used to mount a pressure sensor. The bottom of the cylindrical body is a water inlet. The cylindrical body also has a first grid wave-damping structure and a second grid wave-damping structure. The first and second grid wave-damping structures are arranged sequentially along the water flow direction. Both the first and second grid wave-damping structures have multiple wave-damping teeth. The damping teeth of the first grid damping structure and the second grid damping structure are arranged perpendicular to each other.

2. The wireless transmission compensated pressure gauge with wave reduction structure according to claim 1, characterized in that, The first grid anti-wave structure is formed by multiple first anti-wave teeth arranged in parallel to each other to form a first anti-wave mesh; the second grid anti-wave structure is formed by multiple second anti-wave teeth arranged in parallel to each other to form a second anti-wave mesh.

3. The wireless transmission compensated pressure gauge with wave reduction structure according to claim 2, characterized in that, The plane containing the first and second wave-damping nets is perpendicular to the central axis of the cylindrical body.

4. The wireless transmission compensated pressure gauge with wave reduction structure according to claim 3, characterized in that, The width of the first and second wave-damping teeth along their cross-sections perpendicular to their length gradually increases along the direction of water flow.

5. The wireless transmission compensated pressure gauge with wave reduction structure according to claim 3, characterized in that, The first and second anti-wave teeth have trapezoidal cross sections along their length direction.

6. The wireless transmission compensated pressure gauge with wave reduction structure according to claim 1, characterized in that, The cross-section of the cylindrical body along the vertical central axis consists of a circular arc and a line segment connecting the beginning and end.

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