CN110595428A - Static level gauge for measuring liquid level based on image analysis and measuring method - Google Patents

Abstract

The invention relates to a static level gauge for measuring liquid level based on image analysis and a measuring method, the static level gauge comprises more than two dark boxes, a water pump case, a water tank, a communicating pipe and a bracket, wherein a measuring cylinder, a diffusing light screen and a camera are arranged in the dark boxes, the dark boxes are air-permeable and light-tight boxes, the measuring cylinder is arranged on the inner wall close to one side of the dark boxes, the diffusing light screen is vertically arranged between the measuring cylinder and the adjacent inner wall, the camera is arranged on the inner wall opposite to the diffusing light screen, the bracket supports the communicating pipe, the communicating pipe is connected with the water pump case in series and the liquid of the measuring cylinder in the dark boxes, and the water pump case is connected with the water tank through a pipeline; the measuring method of the hydrostatic level gauge for measuring the liquid level based on image analysis comprises the following steps: step 1: placing equipment, step 2: collecting an image; and step 3: preprocessing an image; and 4, step 4: image-related information is calculated. The invention adopts the image analysis technology to measure the liquid level, intuitively measures the change of the ratio of the water surface area, avoids the errors caused by manually reading data and calculating, and obtains more accurate settlement data.

Description

Static level gauge for measuring liquid level based on image analysis and measuring method

Technical Field

The invention provides a static level gauge for measuring liquid level based on image analysis, belonging to the technical field of structure settlement measurement of civil engineering.

Background

The static leveling system is a precise instrument for measuring relative settlement between two points or between multiple points, and is mainly used for monitoring vertical displacement and inclination of large-scale storage tanks, dams, nuclear power plants, high-rise buildings, foundation pits, tunnels, bridges, subways and the like. When the traditional static level is used, containers of a plurality of static level instruments are connected through liquid pipes, the liquid level of each container is measured by a magnetic telescopic sensor, and the float position of the sensor synchronously changes along with the change of the liquid level, so that the liquid level change of each measuring point can be measured.

There are many types of hydrostatic levels, including: vibrating wire, inductive, liquid level, etc. However, in the process of measuring settlement, the static leveling system suffers from the influence of different temperatures at different positions, and requires a complicated process such as temperature compensation. According to the fluid mechanics principle, the farther the liquid flow distance is, the smaller the water head is, and the larger flow viscosity generated can cause the liquid level to be unequal in height, so that the finally measured result has larger error. Most obviously, the traditional hydrostatic level gauge reads measurement data by means of manual reading, and converts displacement data of the liquid level into other physical quantities for computational analysis. The process of reading and converting the data also results in low accuracy of the measurement result.

Disclosure of Invention

In order to solve the problems, the invention provides a static level gauge for measuring liquid level based on image analysis, which comprises the following specific steps:

the static level gauge for measuring the liquid level based on image analysis comprises a camera bellows, a water pump case, a water tank, a communicating pipe and a bracket, wherein more than two camera bellows are arranged in the camera bellows, the camera bellows is a breathable and lightproof box body, the measuring cylinder is placed on the inner wall of one side close to the camera bellows, the diffuse light screen is vertically placed between the measuring cylinder and the adjacent inner wall of the measuring cylinder, the camera is installed on the inner wall opposite to the diffuse light screen, the communicating pipe is supported by the bracket, the communicating pipe is connected with the water pump case in series and is connected with the liquid of the measuring cylinder in the camera bellows, the water pump case is connected with the water tank through a pipeline, an image collected by the camera is uploaded to be processed by a computer, a gray value is extracted, the ratio of the above-water area and the under-water area in the measuring cylinder is determined, the change information of the liquid is obtained.

Furthermore, the lowest liquid level point of the water pump case is lower than the lowest liquid level point in the measuring cylinder, pure liquid is periodically replaced from the water tank by the water pump case, the liquidity of the liquid is kept, and the temperature of the liquid in the measuring cylinder in the dark box is kept unchanged.

Furthermore, the graduated cylinder is a transparent cylinder, liquid is filled in the graduated cylinder, and the graduated cylinders in each camera bellows are connected in series at the bottom of the camera bellows through communicating pipes.

Further, the liquid is litmus reagent.

Furthermore, the central axis of the camera lens is slightly lower than the liquid level in the measuring cylinder, so that the lifting distance of the liquid level is ensured to be within the shooting range of the camera.

Further, the camera bellows outer wall is equipped with the wide range gleitbretter, wide range gleitbretter (4) adopt the bolt fastening at the camera bellows outer wall, and the wide range gleitbretter is equipped with the scale, through adjusting the flexible of wide range gleitbretter adjustment scale, measuring distance.

The measuring method of the hydrostatic level gauge for measuring the liquid level based on image analysis comprises the following steps:

step 1: placing equipment: placing the mounted static level device on a detection point;

step 2: collecting an image: starting a camera, shooting and recording the change of the liquid level in the measuring cylinder, and transmitting an image to a computer when the liquid level is stable;

and step 3: image preprocessing: extracting a gray value from the image;

and 4, step 4: calculating image related information: the area size of dark liquid in the target image is obtained in least square method fitting screening through MATLAB, and the blank graduated flask area size in liquid level top, the area of dark liquid will be passed through the pixel point, and the space size that the blank graduated flask area in liquid level top was in the image is quantized, according to the area of dark liquid, and the area of dark liquid is obtained to the pixel quantity that the blank graduated flask area in liquid level top was shared in the image, and the blank graduated flask area value in liquid level top, through the ratio between them, with this scale value that liquid level place in obtaining the hydrostatic level.

Has the advantages that:

(1) the liquid volume can be freely expanded, and the measurement result is not influenced by temperature change;

(2) the liquid in the measuring cylinder is replaced regularly, impurities in the measured liquid are cleaned regularly and automatically, the liquidity of the liquid is kept, and the precision of the measuring result is improved;

(3) the liquid level is measured by adopting an image analysis technology, the change of the ratio of the water surface area is measured visually, and errors caused by manual data reading and calculation are avoided, so that more accurate settlement data are obtained.

Drawings

Figure 1 is a schematic view of the overall structure of the present invention,

FIG. 2 is a schematic view of the inside of the camera bellows of the present invention,

the system comprises a camera, a water pump, a water tank, a camera, a water pump case, a camera, a water pump case, a liquid tank and a water tank, wherein the camera is arranged in the camera, the camera is arranged in the water pump case, and the water tank is arranged in the water pump case.

Detailed Description

The present invention is further illustrated by the following examples, which are intended to be purely exemplary and are not intended to limit the scope of the invention, as various equivalent modifications of the invention will occur to those skilled in the art upon reading the present disclosure and fall within the scope of the appended claims.

As shown in FIG. 2, the hydrostatic level for measuring the liquid level based on image analysis comprises a camera bellows 1, a water pump case 7, a water tank 9, a communicating pipe 6 and a bracket, wherein a measuring cylinder 2, a diffusion light screen 3 and a camera 5 are arranged in the camera bellows 1. The camera bellows 1 is a box body which is air-permeable and light-tight and provides a dustproof and no-light environment for the measuring system. The measuring cylinder 2 is arranged close to the inner wall of one side of the dark box 1, liquid 8 with poor adhesion, low density and strong light absorption capacity is filled in the measuring cylinder 2, for example, sodium hydroxide and litmus test solution are added into aqueous solution, the diffusing light screen 3 is vertically arranged between the measuring cylinder 2 and the adjacent inner wall, the camera 5 is arranged on the inner wall of the dark box 1 opposite to the diffusing light screen 3, the camera 5 and the measuring cylinder 2 keep a certain distance, the image shot by the camera 5 can be ensured to accurately record liquid level change, and the diffusing light screen 3 provides diffusing backlight needed by shooting for the camera 5; the wide-range slip sheet 4 is fixed on the outer wall of the camera bellows 1 through bolts, the distance between the camera bellows and the horizontal communicating pipe is measured by adjusting the scale on the wide-range slip sheet, the scale on the wide-range slip sheet 4 is set as the reference height, and the rest wide-range slip sheets 4 uniformly reach the reference height, so that the camera bellows are guaranteed to be placed at the uniform height.

As shown in figure 1, the bottom of the camera bellows 1 is slightly higher than the water pump case 7, the bracket is arranged in the middle of every two camera bellows 1, the communicating pipe 6 is supported at the middle position, the communicating pipe 6 communicates the measuring cylinders 2 in the two camera bellows 1 with the water pump case 7 from the bottom, the liquid 8 is kept to flow smoothly in the whole structure, the water pump case 7 is communicated with the water tank 9, the water pump case 7 regularly replaces the pure liquid 8 from the water tank 9, the main water level of the liquid 8 is controlled, and the influence of the liquid 8 factors is avoided in the measuring process.

The measuring method of the hydrostatic level gauge based on the image analysis and the liquid level measurement comprises the following steps: placing the mounted static level device on a detection point; secondly, collecting images: starting the camera 5, shooting and recording the change of the liquid level in the measuring cylinder 2, and transmitting an image to a computer when the liquid level is stable; then, image preprocessing: extracting a gray value from the image; finally, image-related information is calculated: the area size of dark liquid 8 in the target image is obtained through MATLAB's least square method fitting screening, and 2 area sizes of blank graduated flask in liquid level top, through the area of pixel point with dark liquid 8, and 2 area sizes that the blank graduated flask in liquid level top was accounted for in the image quantize, according to the area of dark liquid 8, and 2 area numbers of pixel points that the blank graduated flask in liquid level top was accounted for in the image obtain the area numerical value of dark liquid in the image, and 2 area numerical values of blank graduated flask in liquid level top, through the ratio between them, with this scale value that liquid level place in obtaining the static spirit level, and can obtain the settlement data of multiple spot through the superposition operation.

The camera bellows adopted by the invention is dustproof and breathable, so that the interior of the camera bellows is not interfered by external environmental factors during measurement; the liquid in the measuring cylinder is replaced regularly, so that the purity of the liquid is guaranteed, the liquid has poor adhesiveness, low density and high fluidity, and the measuring result is not influenced by temperature and magazines; the image analysis technology is adopted to measure the liquid level, the change of the ratio of the water surface area in the measuring cylinder is visually measured, reading errors caused by manual reading of data are avoided, and more accurate settlement data are obtained through calculation.

In light of the foregoing description of the preferred embodiment of the present invention, many modifications and variations will be apparent to those skilled in the art without departing from the spirit and scope of the invention. The technical scope of the present invention is not limited to the content of the specification, and must be determined according to the scope of the claims.

Claims (7)

1. Static water level based on image analysis measures liquid level, its characterized in that: the device comprises a camera bellows (1), a water pump case (7), a water tank (9), a communicating pipe (6) and a bracket, wherein the camera bellows (1) is more than two, a measuring cylinder (2), a diffusing light screen (3) and a camera (5) are arranged in the camera bellows (1), the camera bellows (1) is a breathable and lightproof box body, the measuring cylinder (2) is arranged on the inner wall of one side close to the camera bellows (1), the diffusing light screen (3) is vertically arranged between the measuring cylinder (2) and the adjacent inner wall of the measuring cylinder, the camera (5) is arranged on the inner wall opposite to the diffusing light screen (3), the bracket supports the communicating pipe (6), the communicating pipe (6) is connected with the liquid (8) of the measuring cylinder in the camera bellows (1) in series through the communicating pipe (6), the water pump case (7) is connected with the water tank (9) through a pipeline, the image collected by the camera (5) is uploaded to be processed by, determining the ratio of the above-water area to the underwater area in the measuring cylinder, acquiring the change information of the liquid, and measuring the relative settlement data between two points or multiple points in the measuring cylinder (2).

2. A hydrostatic level measuring liquid level based on image analysis according to claim 1, characterized in that: the lowest liquid level point of the water pump case (7) is lower than that of the measuring cylinder (2), pure liquid (8) is replaced from the water tank (9) by the water pump case (7) regularly, the liquidity of the liquid (8) is kept, and the temperature of the liquid (8) in the measuring cylinder (2) in the dark box (1) is kept unchanged.

3. A hydrostatic level measuring liquid level based on image analysis according to claim 1, characterized in that: the measuring cylinder (2) is a transparent cylinder with scales, liquid (8) is contained in the measuring cylinder (2), and the measuring cylinder (2) in each camera bellows (1) are connected in series at the bottom of the camera bellows (1) through a communicating pipe (6).

4. A hydrostatic level measuring liquid level based on image analysis according to claim 3, characterized in that: the liquid (8) is litmus reagent.

5. A hydrostatic level measuring liquid level based on image analysis according to claim 1, characterized in that: the central axis of the lens of the camera (5) is slightly lower than the liquid level in the measuring cylinder (2), so that the lifting distance of the liquid level is ensured to be within the shooting range of the camera (5).

6. A hydrostatic level measuring liquid level based on image analysis according to claim 1, characterized in that: the camera bellows (1) outer wall is equipped with wide range gleitbretter (4), wide range gleitbretter (4) adopt the bolt fastening at camera bellows outer wall (1), and wide range gleitbretter (4) are equipped with the scale, through adjusting the flexible of wide range gleitbretter (4) adjustment scale, measuring distance.

7. The measuring method of the static level gauge based on the image analysis and the liquid level measurement is characterized in that: the method comprises the following steps:

step 1: placing equipment: placing the mounted static level device on a detection point;

step 2: collecting an image: starting a camera, shooting and recording the change of the liquid level in the measuring cylinder, and transmitting an image to a computer when the liquid level is stable;

and step 3: image preprocessing: extracting a gray value from the image;

and 4, step 4: calculating image related information: the area size of dark liquid in the target image is obtained in least square method fitting screening through MATLAB, and the blank graduated flask area size in liquid level top, the area of dark liquid will be passed through the pixel point, and the space size that the blank graduated flask area in liquid level top was in the image is quantized, according to the area of dark liquid, and the area of dark liquid is obtained to the pixel quantity that the blank graduated flask area in liquid level top was shared in the image, and the blank graduated flask area value in liquid level top, through the ratio between them, with this scale value that liquid level place in obtaining the hydrostatic level.