Water level monitoring device and water level monitoring method

Abstract

The present invention discloses a water level monitoring device and a water level monitoring method. The water level monitoring device includes a measuring device, a gyroscope and a processing device; the measuring device is used to scan the intersection point of the water level liquid surface and a target object and obtain a point cloud map of an initial scanning surface, and transmit the point cloud map of the initial scanning surface to the processing device; the gyroscope is used to detect the current inclination angle information of the measuring device and transmit it to the processing device; the processing device is used to obtain a point cloud map of a real scanning surface corresponding to the point cloud map of the initial scanning surface according to the current inclination angle information, and obtain the height of the water level liquid surface according to the point cloud map of the real scanning surface. The present invention uses a lidar as the measuring device, and has high measurement accuracy.

Description

Technical Field

[0001] The present invention relates to the field of water level monitoring, and particularly to a water level monitoring device and a water level monitoring method. Background Art

[0002] Currently, there are monitoring methods such as water level monitoring stations, radar water level gauges, and float water level gauges for water level monitoring. The monitoring station has high accuracy but a large construction cost, and has high requirements for the construction location and power supply; the radar water level gauge is convenient to install but can only be installed in places perpendicular to the water surface and cannot measure the water level on slopes; the float water level gauge has too low accuracy and is limited by water flow and depth. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome various defects existing in the prior art water level monitoring methods, and provide a water level monitoring device and a water level monitoring method.

[0004] The present invention solves the above technical problem through the following technical solutions:

[0005] The present invention provides a water level monitoring device, including a measurement device, a gyroscope, and a processing device;

[0006] The measurement device is used to scan the intersection point of the water level liquid surface and a target object and obtain a point cloud map of the initial scan plane, and transmit the point cloud map of the initial scan plane to the processing device;

[0007] The gyroscope is used to detect the current inclination angle information of the measurement device and transmit it to the processing device;

[0008] The processing device is used to obtain a point cloud map of the real scan plane corresponding to the point cloud map of the initial scan plane according to the current inclination angle information, and obtain the height of the water level liquid surface according to the point cloud map of the real scan plane.

[0009] Preferably, the point cloud map of the initial scan plane is a polar coordinate system point cloud map of a three-dimensional space section plane. The processing device is used to convert the polar coordinate system point cloud map into an initial Cartesian coordinate system point cloud map, and obtain the real Cartesian coordinate system point cloud map of the real scan plane according to the current inclination angle information.

[0010] Preferably, the processing device includes:

[0011] A point processing unit, which is used to obtain the polar coordinate system point cloud map within a period of time, and generate a stable polar coordinate system point cloud map after removing unstable measurement points. Among them, for multiple measurement points under the same polar angle, if the standard deviation of the polar radii of the multiple measurement points exceeds a preset threshold, the multiple measurement points are all unstable, otherwise the multiple measurement points are all stable;

[0012] A conversion unit for converting a stable polar coordinate point cloud map into a Cartesian coordinate point cloud map;

[0013] A statistical unit for obtaining the mode of all the Y values of the points, counting the frequency of the occurrence of the mode at each angle, obtaining two-dimensional coordinate points with the angle as the horizontal axis and the frequency as the vertical axis, and calculating the initial angle θ corresponding to the maximum absolute value of the slope and the maximum horizontal axis coordinate value;

[0014] A comparison unit for starting from the initial angle θ, comparing the stability of the distances in the first angle interval from θ to θ + N and the second angle interval from θ to θ - N, where the stability is the standard deviation between the standard deviations of the distances at each angle within the interval, and N is the first preset angle interval; if the stability in the first angle interval of [θ - N, θ] is greater than the stability in the second angle interval of [θ, θ + N], then it is determined that the stability of the θ angle is the best at this time, and the Y value of the measurement point corresponding to the θ angle at this time is obtained as the empty height value; if the stability in the first angle interval of [θ - N, θ] is less than the stability in the second angle interval of [θ, θ + N], then θ + k is assigned to θ, and the comparison of the stability is performed again until the stability in the first angle interval of [θ - N, θ] is greater than the stability in the second angle interval of [θ, θ + N], where k is the second preset angle interval.

[0015] Preferably, the processing device further includes:

[0016] A height value processing unit for obtaining the empty height value corresponding to each scan, saving all the empty height values according to the first time period to obtain the first window data, and obtaining the average value of the remaining data after removing the abnormal data in the first window data as the first output data within the first time period;

[0017] The height value processing unit is further used for counting the first output data of multiple first time periods included in the second time period, and obtaining the average value of the multiple first output data as the second output data.

[0018] Preferably, the water level monitoring device further includes a housing, and the measuring device, the gyroscope and the processing device are all arranged in the housing;

[0019] The housing has a measurement window with an opening facing downwards, the measuring device is arranged in the measurement window, and a sunken diversion groove is provided at the measurement window.

[0020] Preferably, the housing is hemispherical, and / or a bubble level is provided on the housing.

[0021] Preferably, the water level monitoring device further includes a temperature control switch and a cooling fan disposed inside the housing, and the temperature control switch is used to start the cooling fan after detecting that the temperature is higher than a set value.

[0022] Preferably, the water level monitoring device further includes a regulated power supply and / or a communication module, and / or, the measuring device includes a lidar.

[0023] The present invention also provides a water level monitoring method, which is implemented by using the above water level monitoring device, and the water level monitoring method includes:

[0024] Scanning the intersection point of the water level surface and a target by a measuring device and obtaining a point cloud map of an initial scanning surface;

[0025] Detecting the current inclination angle information of the measuring device;

[0026] Obtaining a point cloud map of a real scanning surface corresponding to the point cloud map of the initial scanning surface according to the current inclination angle information, and obtaining the height of the water level surface according to the point cloud map of the real scanning surface.

[0027] Preferably, the water level monitoring method specifically includes:

[0028] Obtaining a polar coordinate system point cloud map within a period of time, and generating a stable polar coordinate system point cloud map after removing unstable measurement points. Among them, for multiple measurement points under the same polar angle, if the standard deviation of the polar radii of the multiple measurement points exceeds a preset threshold, then the multiple measurement points are all unstable, otherwise the multiple measurement points are all stable;

[0029] Converting the stable polar coordinate system point cloud map into a Cartesian coordinate system point cloud map;

[0030] Taking the mode of all the Y values of the points, and counting the frequency of the occurrence of the mode at each angle, and obtaining two-dimensional coordinate points with the angle as the horizontal axis and the frequency as the vertical axis, and calculating the initial angle θ corresponding to the maximum absolute value of the slope and the maximum horizontal axis coordinate value;

[0031] Starting from the initial angle θ, compare the stability of the distance in the first angular range from θ to θ + N and the second angular range from θ to θ - N. The stability is the standard deviation of the standard deviations of the distances at each angle within the range, where N is the first preset angular interval. If the stability in the first angular range of [θ - N, θ] is greater than the stability in the second angular range of [θ, θ + N], then determine that the stability of the θ angle is the best at this time, and obtain the Y value of the measurement point corresponding to the θ angle at this time as the empty height value. If the stability in the first angular range of [θ - N, θ] is less than the stability in the second angular range of [θ, θ + N], then assign θ + k to θ and re - perform the comparison of the stability until the stability in the first angular range of [θ - N, θ] is greater than the stability in the second angular range of [θ, θ + N], where k is the second preset angular interval;

[0032] Obtain the empty height value corresponding to each scan, save all the empty height values according to the first time period to obtain the first window data, and after removing the abnormal data in the first window data, obtain the average value of the remaining data as the first output data within the first time period;

[0033] Statistically analyze the first output data of multiple first time periods included in the second time period, and obtain the average value of the multiple first output data as the second output data.

[0034] The positive and progressive effects of the present invention are as follows: The present invention uses lidar as the measurement device, with high measurement accuracy. The effective detection range of the lidar is 100 meters, and the angular resolution is 0.02 degrees. The present invention has low power consumption, and the power during normal operation is less than 20 watts. The present invention has a low cost. Compared with building a water level station, the present invention only requires a vertical pole and a power supply to work. The present invention is easy to install, can be fixed on various brackets, and the device shell is equipped with a bubble level. The installation location of the present invention is easy to select, and it can be installed on the water bank, in the water bank, on the slope, on the wall, etc., and can detect target objects such as dams, slopes, columns, bridge piers, and walls. The device of the present invention is wind - resistant, has a hemispherical shell, conforms to fluid mechanics, and reduces the influence of strong winds on the shaking of the device. The present invention is waterproof, has an IP65 waterproof rating, and the window of the device shell has a diversion groove, which can effectively prevent rainwater from infiltrating into the device interior after installation. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a module schematic diagram of the water level monitoring device according to Embodiment 1 of the present invention.

[0036] Figure 2 It is a module schematic diagram of the processing device of the water level monitoring device according to Embodiment 1 of the present invention.

[0037] Figure 3This is the front view of the water level monitoring device according to Embodiment 1 of the present invention.

[0038] Figure 4 This is the left view of the water level monitoring device according to Embodiment 1 of the present invention.

[0039] Figure 5 This is the top view of the water level monitoring device according to Embodiment 1 of the present invention.

[0040] Figure 6 This is the perspective view of the water level monitoring device according to Embodiment 1 of the present invention.

[0041] Figure 7 This is the point cloud schematic diagram in Embodiment 1 of the present invention.

[0042] Figure 8 This is the two-dimensional coordinate point schematic diagram in Embodiment 1 of the present invention.

[0043] Figure 9 This is the angle interval schematic diagram in Embodiment 1 of the present invention.

[0044] Figure 10 This is the flowchart of the water level monitoring method according to Embodiment 2 of the present invention.

[0045] Figure 11 This is the specific flowchart of the water level monitoring method according to Embodiment 2 of the present invention. Detailed implementation manners

[0046] The present invention will be further described below by way of embodiments, but the present invention is not limited to the scope of the described embodiments.

[0047] Embodiment 1

[0048] This embodiment provides a water level monitoring device, as Figure 1 shown, which includes a measuring device 1, a gyroscope 2 and a processing device 3;

[0049] The measuring device 1 is used to scan the intersection point of the water level surface and a target object and obtain a point cloud map of the initial scanning surface, and transmit the point cloud map of the initial scanning surface to the processing device 3; wherein, the measuring device 1 can specifically scan the intersection points of the page with solids such as the ground, the dam body, and the column, and obtain the point cloud map of the fixed plane where the intersection points are located.

[0050] The gyroscope 2 is used to detect the current inclination information of the measuring device 1 and transmit it to the processing device 3. The gyroscope 2 can specifically return information such as the yaw angle, the pitch angle, and the roll angle. According to these three angles, the three-dimensional posture of the measuring device 1 at present can be determined.

[0051] The processing device 3 is used to obtain the point cloud map of the real scanning plane corresponding to the point cloud map of the initial scanning plane according to the current inclination information, and obtain the height of the water level surface according to the point cloud map of the real scanning plane.

[0052] Specifically, the point cloud map of the initial scanning plane is a polar coordinate system point cloud map of a three-dimensional space section plane (i.e., the two-dimensional scanning plane of the measuring device 1). Among them, the pole of the polar coordinate system can specifically be the measuring device 1, and the polar axis can be customized according to the installation method of the measuring device 1. The point cloud map is composed of a finite number of points, and the number of points is controlled by the angular resolution of the measuring device 1, the size of the housing window where the measuring device 1 is located, and whether there is an echo from the measured target object. The processing device 3 is used to convert the polar coordinate system point cloud map into an initial Cartesian coordinate system point cloud map. Among them, the origin of the Cartesian coordinate system can specifically be the measuring device 1, the X-axis is the horizontal plane, and the Y-axis is perpendicular to the horizontal plane. For example, if the measuring device returns a polar coordinate point (10 cm, 0.3°), it can be converted into the Cartesian coordinate system (sin 0.3° * 10 cm, cos 0.3° * 10 cm), and the real Cartesian coordinate system point cloud map of the real scanning plane is obtained according to the current inclination information. Specifically, the polar axis of the polar coordinate system can be determined according to the current inclination information, and then the polar axis of the polar coordinate system is corrected to be located in the horizontal plane through the inclination information, and the real scanning plane can be obtained.

[0053] In the specific implementation process of the present invention, as Figure 2 shown, the processing device 3 may include:

[0054] A point processing unit 31, which is used to obtain the polar coordinate system point cloud map within a period of time, and generate a stable polar coordinate system point cloud map after removing unstable measurement points. Among them, for multiple measurement points under the same polar angle, if the standard deviation of the polar radii of the multiple measurement points exceeds a preset threshold, then the multiple measurement points are all unstable, otherwise the multiple measurement points are all stable; for example, at the measurement point of the angle 0.3°, the returned data is [100, 101, 102, 103, 99, 98, 97]. Calculate the standard deviation of these points. If it is less than the preset threshold (for example, the preset threshold is 3), then these points are stable in value, otherwise these points are unstable in value and are discarded.

[0055] A conversion unit 32, which converts the stable polar coordinate system point cloud map into a Cartesian coordinate system point cloud map;

[0056] A statistical unit 33, which is used to filter and smooth the point cloud map to obtain a point cloud schematic diagram, and take the mode of all the Y values of the points (for the points scanned by the measuring device 1, the Y value specifically refers to the vertical distance from the point to the measuring device 1) (as Figure 7 shown, 4 in the figure is the mode, specifically in Figure 7In it, the horizontal axis represents X, i.e., the horizontal distance from the measuring device to this point; the vertical axis represents Y, i.e., the vertical distance from the measuring device to this point), and count the frequency of the mode appearing at each angle, and obtain two-dimensional coordinate points with the angle as the horizontal axis and the frequency as the vertical axis (the schematic diagram is as Figure 8 shown, which shows the frequency of the appearance of 4. Specifically, in Figure 8 , the horizontal axis represents the X in Figure 7 , and the vertical axis represents the number of times Y = 4 appears for each specific value of X), and obtain the connection of these two-dimensional coordinate points, and then calculate the initial angle θ corresponding to the maximum absolute value of the slope and the maximum value of the horizontal axis coordinate value (this initial angle specifically refers to the polar angle in the polar coordinate system);

[0057] A comparison unit 33 is used to start from the initial angle θ and compare the stability of the distance (this distance is the polar radius) in the first angle interval from θ to θ + N and the second angle interval from θ to θ - N (the angle interval is specifically as Figure 9 shown). The stability is the standard deviation between the standard deviations of the distances at each angle within the interval. Where N is the first preset angle interval, and N can be an artificially set value. Here, specifically, first calculate the standard deviation sθ accumulated by the θ angle, then calculate the standard deviations sθ+N of other angles in this way, and finally calculate the standard deviation S(sθ,..., sθ+N) of the standard deviations of each angle in the interval [θ, θ + N]; if the stability in the first angle interval from θ - N to θ is greater than the stability in the second angle interval from θ to θ + N, then determine that the stability of the θ angle is the best at this time, and obtain the Y value of the measurement point corresponding to the θ angle at this time as the empty height value (for the point scanned by the measuring device 1, specifically, it refers to the vertical distance from this point to the measuring device 1); if the stability in the first angle interval from θ - N to θ is less than the stability in the second angle interval from θ to θ + N, then assign θ + k to θ and re-perform the comparison of the stability until the stability in the first angle interval from θ - N to θ is greater than the stability in the second angle interval from θ to θ + N, where k is the second preset angle interval.

[0058] Specifically, as shown in Table 1 below, it shows the standard deviations of the distance values of each frame at each angle and the standard deviations (i.e., stabilities) of the two angle intervals. Of course, Table 1 is only an example and does not specifically limit the solution of the present invention. In Table 1, the data obtained by the measuring device scanning one week is one frame. Of course, the time period corresponding to one frame may not be limited to one week, and specifically, other settings can be made according to actual needs. The distance value represents the straight-line distance from the measuring device to the object at this angle, and this distance is provided by the measuring device.

[0059] Table 1

[0060]

[0061] Preferably, the processing device 3 further includes:

[0062] A height value processing unit 34, configured to obtain the empty height value corresponding to each scan, save all the empty height values according to the first time period to obtain first window data, and obtain the average value of the remaining data after excluding abnormal data in the first window data as the first output data within the first time period;

[0063] The height value processing unit is further configured to count the first output data of multiple first time periods included in the second time period, and obtain the average value of the multiple first output data as the second output data.

[0064] As Figure 1 and Figures 3 - 6 shown, the water level monitoring device further includes a housing 4, and the measuring device 1, the gyroscope 2 and the processing device 3 are all arranged in the housing 4;

[0065] The housing 4 has a measurement window 41 with an opening facing downwards, the measuring device 1 is arranged in the measurement window 41, and a sunken diversion groove 42 is provided at the measurement window 41. The housing 4 is hemispherical, and a bubble level 5 is provided on the housing 4. The bubble level 5 can assist the installer to perform horizontal calibration on the entire device to prevent excessive tilting.

[0066] In the present invention, both the measuring device 1 and the processing device 3 are installed inside the housing 4, and the entire device can be installed vertically. The hemispherical housing can effectively resist wind impact. The window provided by the housing 4 for the measuring device 1 faces downwards, which can effectively prevent liquid from invading the inside of the housing 4 from above. The sunken diversion groove 42 on the window of the housing 4 can effectively prevent surface liquid from infiltrating into the device interior along the window gap. During actual use, the overall device is installed near the water surface, and it is necessary to enable the measuring device 1 to detect both the water surface and the detection target (such as a slope, a dam, a column, etc.) at the same time.

[0067] The water level monitoring device further includes a temperature control switch 6 and a cooling fan 7 arranged inside the housing 4. The temperature control switch 6 is configured to start the cooling fan 7 to dissipate heat inside the housing 4 after detecting that the temperature is higher than the set value. In addition, the water level monitoring device further includes a regulated power supply 8 and a communication module 9. The regulated power supply 8 outputs the external power supply into stable direct current, which can better adapt to the unstable power supply provided by batteries or photovoltaic and wind power generation. The communication module 9 can send real-time water level data to the outside for the processing device 3, and specifically can output data to the server or terminal device regularly at a fixed period. Of course, the server or terminal device can also actively obtain the data.

[0068] Among them, the measuring device 1 is preferably a lidar.

[0069] Example 2

[0070] This embodiment provides a water level monitoring method, which is implemented by using the water level monitoring device described in Embodiment 1. As Figure 10 shown, the water level monitoring method includes:

[0071] S1. Scan the intersection point of the water level surface and a target object through a measuring device and obtain a point cloud map of the initial scanning surface;

[0072] S2. Detect the current tilt angle information of the measuring device;

[0073] S3. Obtain a point cloud map of the real scanning surface corresponding to the point cloud map of the initial scanning surface according to the current tilt angle information, and obtain the height of the water level surface according to the point cloud map of the real scanning surface.

[0074] Specifically, as Figure 11 shown, the water level monitoring method may specifically include:

[0075] S11. Obtain a polar coordinate system point cloud map within a period of time, and generate a stable polar coordinate system point cloud map after removing unstable measurement points. Among them, for multiple measurement points under the same polar angle, if the standard deviation of the polar radii of the multiple measurement points exceeds a preset threshold, then the multiple measurement points are all unstable, otherwise the multiple measurement points are all stable;

[0076] S12. Convert the stable polar coordinate system point cloud map into a Cartesian coordinate system point cloud map;

[0077] S13. Take the mode of all the Y values of the points, count the frequency of the mode appearing at each angle, and obtain two-dimensional coordinate points with the angle as the horizontal axis and the frequency as the vertical axis. Calculate the initial angle θ corresponding to the maximum absolute value of the slope and the maximum horizontal axis coordinate value;

[0078] S14. Starting from the initial angle θ, compare the stability of the distances in the first angle interval from θ to θ + N and the second angle interval from θ to θ - N. The stability is the standard deviation between the standard deviations of the distances at each angle within the interval, where N is the first preset angle interval; if the stability in the first angle interval of [θ - N, θ] is greater than the stability in the second angle interval of [θ, θ + N], then determine that the stability of the θ angle is the best at this time, and obtain the Y value of the measurement point corresponding to the θ angle at this time as the empty height value; if the stability in the first angle interval of [θ - N, θ] is less than the stability in the second angle interval of [θ, θ + N], then assign θ + k to θ and re-perform the comparison of the stability until the stability in the first angle interval of [θ - N, θ] is greater than the stability in the second angle interval of [θ, θ + N], where k is the second preset angle interval;

[0079] S15. Obtain the empty height values corresponding to each scan, save all the empty height values according to the first time period to obtain the first window data, and after removing the abnormal data in the first window data, obtain the average value of the remaining data as the first output data within the first time period;

[0080] S16. Count the first output data of multiple first time periods included in the second time period, and obtain the average value of the multiple first output data as the second output data.

[0081] Although the specific implementation manners of the present invention have been described above, those skilled in the art should understand that this is only for illustration. The protection scope of the present invention is defined by the appended claims. Without departing from the principle and essence of the present invention, those skilled in the art can make various changes or modifications to these implementation manners, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A water level monitoring device, characterized in that, it includes a measuring device, a gyroscope and a processing device; the measuring device is used to scan the intersection point of the water level liquid surface and a target object and obtain a point cloud map of the initial scanning plane, and transmit the point cloud map of the initial scanning plane to the processing device; the gyroscope is used to detect the current inclination angle information of the measuring device and transmit it to the processing device; the processing device is used to obtain a point cloud map of the real scanning plane corresponding to the point cloud map of the initial scanning plane according to the current inclination angle information, and obtain the height of the water level liquid surface according to the point cloud map of the real scanning plane; the point cloud map of the initial scanning plane is a polar coordinate system point cloud map of a three-dimensional space section plane, and the processing device is used to convert the polar coordinate system point cloud map into an initial Cartesian coordinate system point cloud map, and obtain the real Cartesian coordinate system point cloud map of the real scanning plane according to the current inclination angle information; the processing device includes: a point processing unit, which is used to obtain a polar coordinate system point cloud map within a period of time, and generate a stable polar coordinate system point cloud map after removing unstable measurement points. Among them, for multiple measurement points under the same polar angle, if the standard deviation of the polar radii of the multiple measurement points exceeds a preset threshold, then the multiple measurement points are all unstable, otherwise the multiple measurement points are all stable; a conversion unit, which is used to convert the stable polar coordinate system point cloud map into a Cartesian coordinate system point cloud map; a statistical unit, which is used to take the mode of all point Y values, count the frequency of the appearance of this mode at each angle, and obtain two-dimensional coordinate points with the angle as the horizontal axis and the frequency as the vertical axis, and calculate the initial angle θ corresponding to the maximum absolute value of the slope and the maximum horizontal axis coordinate value; a comparison unit, which is used to start from the initial angle θ, compare the stability of the distances in the first angle interval from θ to θ + N and the second angle interval from θ to θ - N. The stability is the standard deviation between the standard deviations of the distances at each angle within the interval, where N is the first preset angle interval; if the stability in the first angle interval of [θ - N, θ] is greater than the stability in the second angle interval of [θ, θ + N], then it is determined that the stability of the θ angle is the best at this time, and the Y value of the measurement point corresponding to the θ angle at this time is obtained as the empty height value; if the stability in the first angle interval of [θ - N, θ] is less than the stability in the second angle interval of [θ, θ + N], then θ + k is assigned to θ, and the stability comparison is carried out again until the stability in the first angle interval of [θ - N, θ] is greater than the stability in the second angle interval of [θ, θ + N], where k is the second preset angle interval; the processing device further includes: a height value processing unit, which is used to obtain the empty height value corresponding to each scan, save all the empty height values according to the first time period to obtain the first window data, and obtain the average value of the remaining data after removing abnormal data in the first window data as the first output data within the first time period; among them, for the points scanned by the measuring device, the empty height value refers to the vertical distance from the point to the measuring device; The height value processing unit is further configured to count the first output data of multiple first time periods included in the second time period, and obtain the average value of the multiple first output data as the second output data.

2. The water level monitoring device according to claim 1, wherein, the water level monitoring device further includes a housing, and the measuring device, the gyroscope and the processing device are all arranged in the housing; the housing has a measuring window with an opening facing downward, the measuring device is arranged in the measuring window, and a sunken diversion groove is provided at the measuring window.

3. The water level monitoring device according to claim 2, wherein, the housing is hemispherical, and / or a bubble level is provided on the housing.

4. The water level monitoring device according to claim 2, wherein, the water level monitoring device further includes a temperature control switch and a cooling fan arranged inside the housing, and the temperature control switch is configured to start the cooling fan after detecting that the temperature is higher than a set value.

5. The water level monitoring device according to claim 1, wherein, the water level monitoring device further includes a regulated power supply and / or a communication module, and / or the measuring device includes a lidar.

6. A water level monitoring method, wherein, implemented by using the water level monitoring device according to any one of claims 1-4, and the water level monitoring method includes: scanning the intersection point of the water level liquid surface and a target object by a measuring device to obtain a point cloud map of an initial scanning surface; detecting the current tilt angle information of the measuring device; obtaining a point cloud map of a real scanning surface corresponding to the point cloud map of the initial scanning surface according to the current tilt angle information, and obtaining the height of the water level liquid surface according to the point cloud map of the real scanning surface; the water level monitoring method specifically includes: obtaining a polar coordinate point cloud map within a time period, and generating a stable polar coordinate point cloud map after removing unstable measurement points. Among them, for multiple measurement points under the same polar angle, if the standard deviation of the polar radii of the multiple measurement points exceeds a preset threshold, then the multiple measurement points are all unstable, otherwise the multiple measurement points are all stable; converting the stable polar coordinate point cloud map into a Cartesian coordinate point cloud map; taking the mode of all the Y values of the points, counting the frequency of the occurrence of the mode at each angle, and obtaining two-dimensional coordinate points with the angle as the horizontal axis and the frequency as the vertical axis, and calculating the initial angle θ corresponding to the maximum absolute value of the slope and the maximum horizontal axis coordinate value; Starting from the initial angle θ, compare the stability of the distance in the first angular interval from θ to θ + N and the second angular interval from θ to θ - N. The stability is the standard deviation of the standard deviations of the distances at each angle within the interval, where N is the first preset angular interval. If the stability in the first angular interval [θ - N, θ] is greater than the stability in the second angular interval [θ, θ + N], then determine that the stability of the θ angle is the best at this time, and obtain the Y value of the measurement point corresponding to the θ angle at this time as the clear height value. If the stability in the first angular interval [θ - N, θ] is less than the stability in the second angular interval [θ, θ + N], then assign θ + k to θ and re - perform the comparison of the stability until the stability in the first angular interval [θ - N, θ] is greater than the stability in the second angular interval [θ, θ + N], where k is the second preset angular interval. Obtain the clear height value corresponding to each scan, save all the clear height values according to the first time period to obtain the first window data, and after removing the abnormal data in the first window data, obtain the average value of the remaining data as the first output data in the first time period. Among them, for the points scanned by the measuring device, the clear height value refers to the vertical distance from the point to the measuring device. Statistically analyze the first output data of multiple first time periods included in the second time period, and obtain the average value of the multiple first output data as the second output data.

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