Automatic water level monitoring system based on buoyancy conversion elevation, monitoring method and monitoring well

Abstract

The invention provides an automatic water level monitoring system based on buoyancy conversion elevation, a monitoring well and a water level monitoring method. The monitoring system comprises a buoyancy unit, a tension detection unit, a water level identification unit, a processor, a driving unit and a reading unit. Wherein the buoyancy unit floats in underground water in the monitoring well; the tension detection unit is arranged on the buoyancy unit; the water level identification unit can be wound and stretched when the water level changes; the tension detection unit is used for detecting tension change of the water level identification unit when the water level changes and can transmit detection data to the processor; the processor sends an instruction to the driving unit when the actual pulling force of the water level identification unit is inconsistent with the pulling force threshold value; the driving unit drives the water level identification unit to ascend or descend according to an instruction of the processor so as to ascend or descend the buoyancy unit; the reading unit is used for reading the value of the water level identification unit and determining the water level in the monitoring well. Based on buoyancy conversion elevation design, the real-time performance, precision and stability of water level monitoring can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering construction dewatering, in particular to water level monitoring, and in particular to an automatic water level monitoring system, a monitoring method and a monitoring well based on buoyancy conversion elevation. Background Art

[0002] In foundation pit projects, underground projects and other projects involving soil excavation, groundwater has an important impact on the safety of the project, so it is necessary to monitor the groundwater level in real time during the construction process. At present, the commonly used groundwater level monitoring methods include: manual measurement method, automatic measurement method based on the principle of photoelectric refraction, and automatic measurement method based on the principle of capacitance. Manual measurement method: When the detection head of the steel ruler water level gauge sensor contacts the water body, an induced potential is generated. After circuit processing, an acoustic and photoelectric indication is issued, and then the height difference between the water surface and the ground is manually read from the ruler. Automatic measurement method based on the principle of photoelectric refraction: This detection method emits a light source from the inside of the sensor, and the light source is fully reflected to the sensor receiver through the transparent resin. However, when encountering the liquid surface, part of the light will be refracted to the liquid, so that the sensor detects the decrease in the value of the fully reflected light to monitor the liquid level. Automatic measurement method based on the principle of capacitance: Capacitive measurement mainly measures the water level by detecting the change in capacitance value caused by the change in liquid level.

[0003] The manual measurement method requires manual reading and operation, and cannot monitor the groundwater level in real time. The automated measurement method based on the principle of photoelectric refraction can only be used for transparent liquids, and only outputs switch signals. In actual measurements, the groundwater in the observation well is often turbid, and accuracy cannot be guaranteed. Automated measurement method based on the principle of capacitance: Capacitive sensors are easily affected by the environment and solution properties. In summary, the existing methods have the following disadvantages:

[0004] (1) Poor real-time performance

[0005] Conventional devices cannot accurately capture real-time changes in water levels, and data feedback is not timely.

[0006] (2) Low accuracy

[0007] The equipment has low accuracy. Currently, the monitoring accuracy is mostly at the decimeter level, which does not meet the requirements for deep foundation pit monitoring.

[0008] (3) Prone to failure

[0009] At present, there is a lack of water level meters specifically designed for deep well monitoring in complex situations. The liquid level meters used for automated water level monitoring in actual construction are easily affected by silt and underground debris, and often fail, resulting in inaccurate data. Summary of the invention

[0010] In view of the deficiencies in the prior art, the present invention provides an automated water level monitoring system, a monitoring method and a monitoring well based on buoyancy conversion elevation to solve one or more deficiencies in the prior art.

[0011] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0012] The first aspect of the present invention provides an automatic water level monitoring system based on buoyancy conversion elevation, comprising a buoyancy unit, a tension detection unit, a water level marking unit, a processor, a driving unit and a reading unit, wherein:

[0013] The buoyancy unit floats in the groundwater in the monitoring well and is at least partially immersed below the water surface; the tension detection unit is arranged on the buoyancy unit; the drive unit and the processor are arranged outside the monitoring well; one end of the water level marking unit is connected to the tension detection unit, and the other end is wound and connected to the drive unit, and can be wound and retracted when the water level changes;

[0014] The tension detection unit is used to detect the tension change of the water level identification unit when the water level changes, and can transmit the detection data to the processor; the processor is electrically connected to the drive unit, and is used to receive and process the tension change of the water level identification unit detected by the tension detection unit, and the processor is preset with a tension threshold, and when the actual tension of the water level identification unit is inconsistent with the tension threshold, sends an instruction to the drive unit; the drive unit drives to lift or lower the water level identification unit to lift or lower the buoyancy unit according to the instruction of the processor until the actual tension of the water level identification unit is consistent with the tension threshold again;

[0015] The reading unit is arranged outside the monitoring well, and is used to read the value of the water level identification unit and determine the water level in the monitoring well.

[0016] Optionally, the buoyancy unit is a float which is filled with a liquid having a density consistent with that of groundwater in the monitoring well and is sealed.

[0017] Optionally, the tension detection unit adopts a tension sensor.

[0018] Optionally, the water level marking unit adopts a reading tape measure, the driving unit adopts an electric motor, one end of the reading tape measure is connected to the tension detection unit, and the other end is wound and connected to the output end of the electric motor.

[0019] Optionally, the reading unit includes:

[0020] A rotating wheel is connected to the electric motor and can be driven to rotate by the electric motor, and the rotating wheel is wound around the reading tape, and a plurality of infrared reflection points are evenly spaced circumferentially arranged on the rotating wheel;

[0021] An infrared sensor is arranged near the rotating wheel at a predetermined position, corresponding to the infrared recognition area on the rotating wheel, for identifying the infrared reflection point on the rotating wheel and reversely calculating the length of the reading tape, thereby obtaining the water level difference;

[0022] Alternatively, the reading unit comprises:

[0023] A rotating wheel is connected to the electric motor and can be driven to rotate by the electric motor, and the rotating wheel winds up the reading tape measure;

[0024] The CCD image sensor is arranged near the rotating wheel at a predetermined position, and a recognizable measurement barcode is written on the reading tape for the CCD image sensor to identify and read.

[0025] Optionally, the recognizable measurement barcode is a code segment of 10 mm×10 mm, including:

[0026] Leading area: set at the top, used to separate adjacent coding areas. The CCD image sensor can identify the beginning of a new code segment and capture an image through the leading area;

[0027] Ten-meter position identification area: set below the leading area, it is a horizontal barcode, and the ten-meter position is read by identifying the width ratio of the black and white barcodes;

[0028] Centimeter position identification area: set below the ten-meter position identification area, it is three vertical bar codes, corresponding to the meter position, decimeter position, and centimeter position from one side to the other side. By identifying the ratio of the height of the black and white codes of the three vertical bar codes respectively, the centimeter position can be read;

[0029] Millimeter digit precision reading area: It is set on the right side. After the leading area reads the new code segment, the CCD image sensor outputs the millimeter digit reading by capturing the overlapping part between the sighting axis and the barcode.

[0030] A second aspect of the present invention provides an automatic water level monitoring method based on the above automatic water level monitoring system, comprising the following steps:

[0031] Set the pull threshold F of the processor 拉 , so that it has the same gravity as the water level mark unit;

[0032] The tension detection unit detects the tension value F of the water level marking unit in real time. ’ 拉 , and transmits it to the processor;

[0033] The processor receives the tension value F ’ 拉 and compare it with the tension threshold F 拉Compare and judge, and send corresponding driving instructions to the driving unit according to the judgment result:

[0034] If F ’ 拉 =F 拉 , the drive unit does not work,

[0035] If F ’ 拉 >F 拉 The driving unit drives the water level marking unit to be lowered until F ’ 拉 =F 拉 , the driving unit stops working,

[0036] If F ’ 拉 <F 拉 The driving unit drives and lifts the water level marking unit until F ’ 拉 =F 拉 , the driving unit stops working;

[0037] The reading unit reads the actual tension value F ’ 拉 With the tension threshold F 拉 The value of the water level identification unit in the consistent state determines the water level in the monitoring well.

[0038] A third aspect of the present invention provides an automated water level monitoring well based on buoyancy conversion elevation, including a monitoring well unit, and the automated water level monitoring system described above.

[0039] Optionally, the monitoring well comprises:

[0040] The bridge-type water filter pipe has at least one inwardly concave bridge-shaped gap on its pipe body to reduce the ingress of particles;

[0041] An outer filter screen is covered on the outer periphery of the pipe body of the bridge type water filter pipe;

[0042] A fastening steel ring is fastened to the outer filter screen at the butt connection of two adjacent upper and lower bridge-type water filter pipes to fasten the bridge-type water filter pipes.

[0043] Optionally, the bridge-type water filter pipe is a socket-and-spigot type pipe body structure, and its upper and lower ends have sockets that fit together.

[0044] The beneficial effects of the present invention compared to the prior art are: the automatic water level monitoring system, monitoring method and monitoring well based on buoyancy conversion elevation provided by the present invention are intended to improve the real-time, accuracy and stability of water level monitoring through the comprehensive design of software and hardware. Specifically, it can at least bring the following beneficial effects:

[0045] 1. The monitoring well structure and connection method have been optimized. By optimizing the socket and external filter, the common problem of siltation in the siltation layer affecting water level monitoring has been avoided;

[0046] 2. Design a new measurement system to obtain water surface elevation data through the relationship between buoyancy and gravity, thus avoiding the error source of conventional level gauges in deep foundation pit water level measurement in principle;

[0047] 3. Designed an observation system using infrared sensor counting, which makes the observation accuracy reach 4cm, meeting the needs of conventional water level monitoring;

[0048] 4. An observation system based on CCD image recognition was designed, and a set of codes was designed specifically. At the same time, a decoding unit was set up at the wellhead to provide readings and data solutions, and transmit them to the monitoring platform in real time, providing four-dimensional monitoring of three-dimensional space and time sequence, and real-time monitoring of the water level rise rate and rising water level, so that the observation accuracy reached 0.2mm, meeting the dynamic monitoring needs of deep foundation pit water level.

[0049] It should be understood that the implementation of any embodiment of the present invention does not mean that multiple or all of the above-mentioned beneficial effects must be possessed or achieved at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0051] The structures, proportions, sizes, etc. illustrated in this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with the technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantial technical significance. Any structural modification, change in proportion or adjustment in size shall still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0052] Figure 1 A schematic diagram of the overall layout of an automated water level monitoring well in one implementation mode;

[0053] Figure 2 A schematic diagram of the structure of an automated water level monitoring system based on buoyancy conversion elevation according to an implementation method;

[0054] Figure 3 A schematic diagram of a measurement unit based on buoyancy conversion elevation according to an implementation method;

[0055] Figure 4 A schematic diagram of a reading system according to an embodiment;

[0056] Figure 5 is a schematic diagram of a reading system 2 according to an embodiment;

[0057] Figure 6 A schematic diagram of a second encoding code segment of a reading system according to an embodiment;

[0058] Figure 7 A schematic diagram of CCD recognition of a reading system II according to an embodiment (26.455 m);

[0059] Figure 8 A schematic diagram of a monitoring well pipe body structure in one implementation manner;

[0060] Fig. 9 A schematic diagram of a monitoring well socket in one embodiment;

[0061] Fig.10 A schematic diagram of a monitoring well entity structure in one implementation mode;

[0062] Fig.11 The present invention is a flow chart of a water level monitoring method according to an embodiment of the present invention.

[0063] Markings in the figure:

[0064] Buoyancy unit 1, tension detection unit 2, water level marking unit 3, processor 4, drive unit 5, reading unit 6, rotating wheel 61, infrared sensor 62, infrared reflection point 63, CCD image sensor 64, measurement barcode 65, bridge-type water filter pipe 7, outer filter screen 8, fastening steel ring 9, bridge-shaped gap 10, socket 11;

[0065] Monitoring well 100.

[0066] In the various drawings, the same or corresponding reference numerals represent the same or corresponding parts. DETAILED DESCRIPTION

[0067] In order to make the purpose, technical solution and advantages of the embodiments of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in conjunction with the embodiments and drawings. Here, the illustrative embodiments of the present invention and their description are used to explain the present invention, but are not intended to limit the present invention.

[0068] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0069] It should be understood that the terms "include / comprise", "consist of..." or any other variations are intended to cover non-exclusive inclusion, so that a product, device, process or method that includes a series of elements includes not only those elements, but also may include other elements not explicitly listed when necessary, or also includes elements inherent to such product, device, process or method. In the absence of more restrictions, the elements defined by the sentence "include / comprise...", "consist of..." do not exclude the presence of other identical elements in the product, device, process or method that includes the elements.

[0070] It is also necessary to understand that terms such as "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside" and "outside" to indicate directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device, component or structure must have a specific direction, be constructed or operate in a specific direction, and should not be understood as a limitation on the present invention.

[0071] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0072] Aiming at the shortcomings of existing monitoring methods, such as poor real-time performance, low precision and easy failure, the present invention provides an automated water level monitoring well, aiming to improve the real-time performance, precision and stability of water level monitoring through the comprehensive design of software and hardware:

[0073] 1. Through software and hardware design, the purpose of real-time and comprehensive feedback of water level changes can be achieved;

[0074] 2. Improve the accuracy of water level monitoring, and increase the accuracy from decimeter level to centimeter or even millimeter level;

[0075] 3. Improve the stability of monitoring instruments in dealing with complex underground environments and reduce the impact of the environment on monitoring accuracy.

[0076] like Figure 1 As shown, the overall concept and composition of the automatic water level monitoring well of the present invention can be divided into a monitoring well, a measuring part, a reading part, and a decoding part. In the measurement process, two different precision measurement methods are selectively used according to the actual situation. One is based on infrared recognition technology, and the water level measurement accuracy is ≤0.1m. The other is based on CCD sensor recognition technology, and a measuring rope encoding and decoding mechanism is set, and the water level measurement accuracy is ≤1mm. The two monitoring systems meet the monitoring requirements under different precision requirements respectively, and can also perform combined observation, data comparison, and verify the validity of the data.

[0077] The implementation of the present invention is described in detail below with reference to specific implementation methods and drawings.

[0078] At present, water level observation is mostly aimed at liquid level surfaces such as rivers. For water level monitoring of deep wells, water level gauges based on water pressure are often used. Since the actual well depth cannot be accurately measured, the initial value of water level measurement is not accurate enough, and the accuracy of the reverse calculated water level cannot be guaranteed. In order to improve the actual measurement accuracy and avoid the collection of the initial value of the well depth, combined with construction experience, an automatic water level monitoring system based on buoyancy conversion elevation is proposed, which is applied to monitoring wells 100 to monitor the water level in the well in real time and with high precision, such as Figure 2 As shown, it mainly includes a buoyancy unit 1, a tension detection unit 2, a water level marking unit 3, a processor 4, a driving unit 5 and a reading unit 6.

[0079] Specifically, the buoyancy unit 1 and the tension detection unit 2 are arranged in the monitoring well 100, and the processor 4 and the driving unit 5 are arranged outside the monitoring well 100, for example, at a suitable position outside the wellhead of the monitoring well, and can be installed and fixed on a fixed facility through a fixing plate (shown in the blue rectangular area in the figure).

[0080] In some embodiments, the buoyancy unit 1 adopts a float. The present invention adopts a hollow plastic cylinder with a wall thickness of 2 mm, a diameter of 10 cm, and a height of 15 cm, which is filled with a liquid with the same density as the groundwater in the monitoring well and sealed so that it can stably float in the groundwater in the monitoring well.

[0081] In some embodiments, the tension detection unit 2 uses a tension sensor, which is disposed on the upper surface of the buoy, for example, fixed by gluing or screws, and is connected to the processor 4 at the wellhead via a data line.

[0082] The water level marking unit 3 adopts a long strip or strip-shaped structure with a soft texture. It is used to extend into the well from above the wellhead to monitor the water level height and water level changes. One end of it is connected to the tension detection unit 2 in the well, and the other end is wound and connected to the drive unit 5 outside the wellhead, and can be wound and retracted by the drive unit 5 when the water level rises or falls.

[0083] In some embodiments, the water level marking unit 3 uses a reading tape, such as a soft tape measure, and the driving unit 5 uses an electric motor. One end of the reading tape is connected to the top of the tension sensor, and the other end is wound and connected to the output end of the electric motor, for example, wound around the output shaft of the electric motor, so that the electric motor can rotate to "retract" or "release" the reading tape when needed.

[0084] The reading unit 6 is arranged outside the monitoring well 100 . After the above-mentioned error is eliminated, the value of the water level identification unit 3 is read by means of the reading unit 6 and the water level in the monitoring well 100 is determined accordingly.

[0085] The buoyancy unit 1 floats in the groundwater in the monitoring well and is at least partially immersed below the water level. When the hollow plastic cylinder is immersed in water, it is always subject to three forces: its own gravity G, the buoyancy F of the liquid in the well, and the buoyancy F of the liquid in the well. 浮 , the tension F of water level marking unit 3 拉 . Among them, F 拉 It is a preset tension threshold value, which should ensure that the water level identification unit 3 is always in a vertical state to ensure the accuracy of water level monitoring.

[0086] Specifically, when the water level changes, the buoyancy unit 1 can float or sink following the change of the water level, thereby causing the water level identification unit 3 to react and its tension to change; the tension detection unit 2 is used to detect the tension change of the water level identification unit 3 and can transmit the detection data to the processor 4; the processor 4 is electrically connected to the driving unit 5, and is used to receive and process the tension change of the water level identification unit 3 detected by the tension detection unit 2, and the processor 4 is preset with a tension threshold F 拉 (Tension threshold F 拉 It can be the tension value of the water level identification unit 3 when the buoyancy unit 1 is at a certain water level in the initial state), and the actual tension F of the water level identification unit 3 detected is ’ 拉 With the tension threshold F 拉 For comparison, the actual pulling force F ’ 拉 With the tension threshold F 拉 If the water level marking unit 3 is inconsistent, the instruction is sent to the driving unit 5; the driving unit 5 drives the lifting or lowering of the water level marking unit 3 to lift or lower the buoyancy unit 1 according to the instruction of the processor 4 until the actual tension F of the water level marking unit 3 is ’ 拉 With the tension threshold F 拉 The purpose of consistency again is to ensure that the water level height of the buoyancy unit 1 immersed in the monitoring well 100 is always consistent.

[0087] For example, when the water level rises, the volume of the hollow plastic cylinder intruding into the liquid increases, and the F浮 The buoyancy unit 1 floats up with it, and the water level marking unit 3 curls and shortens. At this time, the actual tension F of the water level marking unit 3 ’ 拉 The tension detection unit 2 detects the tension reduction and sends the detection data to the processor 4. The processor 4 sends an instruction to the drive unit 5 after calculation. The drive unit 5 makes a "retraction" action on the water level marking unit 3, that is, lifts the hollow plastic cylinder to offset its shortening, that is, lifts the water level marking unit 3 upward, so that the actual tension F ’ 拉 With the tension threshold F 拉 Once again, the electric motor stopped working.

[0088] Similarly, when the water level drops, the volume of the hollow plastic cylinder that intrudes into the liquid becomes smaller, and the F 浮 The buoyancy unit 1 sinks with it, and the water level marking unit 3 is stretched. At this time, the actual tension F of the water level marking unit 3 ’ 拉 The tension detection unit 2 detects that the tension is increasing, and sends the detection data to the processor 4. After calculation, the processor 4 sends an instruction to the drive unit 5. The drive unit 5 makes a "release" action on the water level marking unit 3, and lowers the hollow plastic cylinder to offset its stretching, that is, to lower the water level marking unit 3, so that the actual tension F ’ 拉 With the tension threshold F 拉 Again consistent.

[0089] To sum up, when the water level changes, the water level marking unit 3 is adjusted by the electric motor, no matter it is "retracted" or "released", the ultimate goal is to make the water level height of the hollow plastic cylinder immersed in the monitoring well 100 always remain consistent. If the immersion height is consistent, the buoyancy of the buoyancy unit 1 remains unchanged, thereby eliminating the monitoring error caused by the change in the length of the water level marking unit 3 when the water level changes (the change in the length of the water level marking unit 3 means the change in weight, and the change in weight means the change in the original force balance system, and the immersion depth of the buoyancy unit 1 changes, which will cause monitoring errors), which is particularly important for high-precision monitoring.

[0090] See also Figure 3 , 4The present invention provides a specific implementation of the reading unit 6, referred to as a reading system 1, including a rotating wheel 61 and an infrared sensor 62, wherein the rotating wheel 61 is connected to an electric motor and can be driven to rotate by the electric motor, a reading tape is wound on the rotating wheel 61, and a plurality of infrared reflection points 63 are evenly spaced circumferentially arranged on the rotating wheel 61. The infrared sensor 62 is arranged near the rotating wheel 61 at a predetermined position, corresponding to the infrared recognition area on the rotating wheel 61, for identifying the infrared reflection points 63 on the rotating wheel 61 and inversely calculating the length of the reading tape, thereby obtaining the water level difference, that is, the difference between the water level and the ground, and further inversely calculating the water level height according to the surface elevation.

[0091] The measuring principle of the reading unit 6 is: by installing an infrared sensor and setting b infrared reflection points on the rotating wheel, by recording the number of reflections n1, the diameter of the rotating wheel at the measuring point is set to D, the corresponding elevation of the non-integer circle of the rotating wheel is h1, and the highest accuracy of the system is σ h1 Indicates that the length of the measuring rod is calculated inversely to obtain the water level difference:

[0092]

[0093]

[0094]

[0095] Note: When D=20cm, the value of b increases, σ h1 The accuracy can be improved accordingly, but considering the wheel area and the actual installation position of the reflection point, b=16 is selected, σ h1 =4cm.

[0096] The above-mentioned reading unit can only achieve a measurement accuracy of 4cm due to the system's own reasons. In conventional water level monitoring, the accuracy is fully satisfied. However, in urban deep foundation pit precipitation measurement, higher requirements are often put forward. Single static data cannot satisfy the user's desire to predict the water level change trend by observing tiny variables in the well over a period of time. Based on this demand, the present invention further provides another reading unit solution to meet such requirements.

[0097] Continue to see Figure 3 Combined with Figure 5 As shown, the present invention provides another more accurate implementation of the reading unit 6, referred to as the second reading system, wherein the reading unit 6 comprises a rotating wheel 61 and a CCD image sensor 64, wherein the rotating wheel 61 is connected to an electric motor and can be driven to rotate by the electric motor, and the rotating wheel 61 winds up a reading tape measure. The CCD image sensor 64 is arranged near the rotating wheel 61 at a predetermined position, and a recognizable measurement barcode 65 is written on the reading tape measure for the CCD image sensor 64 to identify and read.

[0098] By using CCD image sensors and designing a set of recognizable barcodes, writing them on the measuring ruler, and utilizing CCD elements to recognize and interpret the image, accurate positioning and reading of the measuring ruler can be achieved.

[0099] The present invention designs a 10mm×10mm code segment and selects a 12mm×12mm CCD chip to ensure that the resolution of the hardware recognition image can meet the accuracy requirements. The accuracy of the system is determined by the encoding, σ h2 =1mm, the coding description will be elaborated in detail later.

[0100] Due to the relative fluctuation of water level, the millimeter position fluctuates greatly. In order to reduce redundant data and provide more accurate data services, the design program observes the reading values ​​25 times within 10 seconds, compares and corrects with the XX.Xm data of reading system one (the data form of reading system one), and then performs iterative adjustment for centimeters and millimeters separately. For example, when comparing and interpreting data, the decimeter position of the two systems should be consistent. If not, the alarm is manually verified and the consistency is detected. Then, the centimeter and millimeter positions are processed. The system enters 25 sets of data, calculates the average value, and limits the error to 3 times σ h2 , carefully read the data, filter out unfavorable data, and assume that the average is the true value, and calculate the mean error for subsequent data. If the mean error does not meet the accuracy requirement of 1 times σ h2 , carefully read the data, repeatedly enter new data, and perform calculations until the data meets the accuracy requirements.

[0101] In view of the above-mentioned reading system 2, the present invention proposes a new encoding and decoding method to determine: the position of the sighting axis of the CCD image sensor: after the CCD image sensor obtains the code of the code area, the code area number is obtained according to the relationship between adjacent bar code identifiers in the code area, that is, the rough measurement value of each bar code can be obtained; the height value represented by each pixel of the CCD image sensor and the pixel from each bar code in the code area to the reference line can obtain the precise measurement value of the bar code, and the rough measurement value and the precise measurement value are combined into the final measurement result.

[0102] like Figure 6 As shown, the 10mm×10mm code segment is divided into four areas, namely the leading area, the 10-meter position recognition area, the centimeter position recognition area, and the millimeter position precision reading area.

[0103] Preamble area: Adjacent code areas are separated by setting a preamble area in each code segment. The camera can recognize the beginning of a new code segment and capture the image through the preamble area.

[0104] Ten-meter position identification area: Under the leading area, a horizontal coding area is set, through which the black and white barcode width ratio is identified to achieve 10-meter position reading of 10 meters to 50 meters (for example: X0.000M). The coding rules are shown in Table 1 for the relationship between digital codes and black and white barcodes.

[0105] Centimeter position recognition area: Under the ten-meter position recognition area, three vertical barcodes are set, corresponding to the meter position, decimeter position, and centimeter position from left to right. By identifying the ratio of the height of the black and white codes of the three barcodes respectively, the centimeter position can be read (for example: XX.XX0M).

[0106] Millimeter precision reading area: Since the code segment is 10mm×10mm, a millimeter precision reading area is set on the right. After the new code segment is read through the leading area, the CCD image sensor can output the millimeter reading (for example: XX.XXXM) by capturing the overlapping part between the sight axis and the barcode. Figure 7 shown.

[0107] Table 1 Relationship between digital code and black and white barcode

[0108]

[0109] Based on the above measurement principles, the obtained data is automatically read. The present invention proposes two monitoring systems to meet the monitoring requirements under different accuracy requirements respectively, and can also perform combined observation to verify the validity of the data.

[0110] With the aid of the above-mentioned automatic water level monitoring system, the present invention relates to an automatic water level monitoring well based on buoyancy conversion elevation.

[0111] During the construction of deep foundation pits in cities, multiple observation wells are often set up around them. To ensure observation accuracy, the observation wells only monitor static water levels. Therefore, in the actual construction process, after the initial well washing, the observation wells are prone to siltation due to many geological conditions, especially silt layers and silty clay layers, resulting in a disconnection of the water system inside and outside the well, limiting observation.

[0112] In order to avoid this situation, based on construction experience, the monitoring well structure and construction method are optimized as follows: Figure 8 As shown, the monitoring well is composed of a bridge-type water filter pipe 7, an outer filter screen 8, and a fastening steel ring 9.

[0113] The bridge-type water filter pipe adopts a steel pipe body structure, and the pipe body is provided with at least one annular inwardly concave bridge-shaped gap 10, and the bridge-shaped gap is at least 1.5 mm to reduce the entry of particulate matter; the outer filter screen 8 is covered on the outer periphery of the pipe body of the bridge-type water filter pipe 7 throughout its length; the fastening steel ring 9 is fastened to the outer filter screen 8 at the butt connection of the upper and lower adjacent sections of the bridge-type water filter pipe 7 to fasten the bridge-type water filter pipe 7 to ensure that the filter screen is firmly installed and not damaged.

[0114] Continue to see Fig. 9The bridge-type water filter pipe 7 is a socket-type pipe body structure, and its upper and lower ends have mutually matching sockets 11. The lower end socket 11 of the upper pipe body is inserted into the upper end socket 11 of the lower pipe body, and the lower end socket 11 of the bridge-type water filter pipe 7 is concave, so that a gap is formed between the lower end socket 11 and the upper end socket 11 for the outer filter screen 8 to be embedded therein, so as to seal the plug-in joint. By adding a socket, on the one hand, it is convenient for actual construction, and on the other hand, it increases the tightness of the connection between the steel pipe wells and avoids siltation caused by loose connection between pipes. The physical structure of the bridge-type water filter pipe 7 is as follows: Fig.10 shown.

[0115] Through the optimized design of monitoring wells, the probability of monitoring well failure is greatly reduced, ensuring that the monitoring wells are in normal working condition and providing protection for groundwater level monitoring.

[0116] Combination Fig.11 The automatic water level monitoring method of the automatic water level monitoring well of the present invention is as follows:

[0117] Set the pull threshold F of processor 4 拉 , so that it has the same gravity as the water level marking unit 3;

[0118] The tension detection unit 2 detects the tension value F of the water level marking unit 3 in real time ’ 拉 , and transmit to processor 4;

[0119] Processor 4 receives the tension value F ’ 拉 and compare it with the tension threshold F 拉 Compare and judge, and send corresponding driving instructions to driving unit 5 according to the judgment result:

[0120] If F ’ 拉 =F 拉 , drive unit 5 does not work,

[0121] If F ’ 拉 >F 拉 , the driving unit 5 drives the water level marking unit 3 to be lowered until F ’ 拉 =F 拉 , drive unit 5 stops working,

[0122] If F ’ 拉 <F 拉 , the driving unit 5 drives the water level marking unit 3 to lift until F ’ 拉 =F 拉 , the driving unit 5 stops working;

[0123] The reading unit 6 reads the value of the water level identification unit 3 and determines the water level in the monitoring well.

[0124] By means of the water level monitoring method of the automatic water level monitoring system of the present invention, the actual tension F ’ 拉 With the tension threshold F 拉 Always keep consistent, that is, make the water level height of the buoyancy unit 1 immersed in the monitoring well always keep consistent. If the immersion height is consistent, the buoyancy of the buoyancy unit 1 remains unchanged, thereby eliminating the monitoring error caused by the change in the length of the water level identification unit 3 when the water level changes, and ensuring the accuracy of the monitoring results.

[0125] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned preferred solutions can be freely combined and superimposed.

[0126] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An automated water level monitoring system based on buoyancy conversion elevation, characterized in that: It includes a buoyancy unit, a tension detection unit, a water level marking unit, a processor, a driving unit and a reading unit, wherein: The buoyancy unit floats in the groundwater in the monitoring well and is at least partially immersed below the water surface; the tension detection unit is arranged on the buoyancy unit; the drive unit and the processor are arranged outside the monitoring well; one end of the water level marking unit is connected to the tension detection unit, and the other end is wound and connected to the drive unit, and can be wound and retracted when the water level changes; The tension detection unit is used to detect the tension change of the water level identification unit when the water level changes, and can transmit the detection data to the processor; the processor is electrically connected to the drive unit, and is used to receive and process the tension change of the water level identification unit detected by the tension detection unit, and the processor is preset with a tension threshold, and when the actual tension of the water level identification unit is inconsistent with the tension threshold, sends an instruction to the drive unit; the drive unit drives to lift or lower the water level identification unit to lift or lower the buoyancy unit according to the instruction of the processor until the actual tension of the water level identification unit is consistent with the tension threshold again; The reading unit is arranged outside the monitoring well, and is used to read the value of the water level identification unit and determine the water level in the monitoring well.

2. The automatic water level monitoring system according to claim 1, characterized in that: The buoyancy unit adopts a buoy which is filled with liquid having the same density as the groundwater in the monitoring well and is sealed.

3. The automatic water level monitoring system according to claim 1, characterized in that: The tension detection unit adopts a tension sensor.

4. The automatic water level monitoring system according to claim 1, characterized in that: The water level marking unit adopts a reading tape measure, the driving unit adopts an electric motor, one end of the reading tape measure is connected to the tension detection unit, and the other end is wound and connected to the output end of the electric motor.

5. The automatic water level monitoring system according to claim 4, characterized in that: The reading unit comprises: A rotating wheel is connected to the electric motor and can be driven to rotate by the electric motor, and the rotating wheel is wound around the reading tape, and a plurality of infrared reflection points are evenly spaced circumferentially arranged on the rotating wheel; An infrared sensor is arranged near the rotating wheel at a predetermined position, corresponding to the infrared recognition area on the rotating wheel, for identifying the infrared reflection point on the rotating wheel and reversely calculating the length of the reading tape, thereby obtaining the water level difference; Alternatively, the reading unit comprises: A rotating wheel is connected to the electric motor and can be driven to rotate by the electric motor, and the rotating wheel winds up the reading tape measure; The CCD image sensor is arranged near the rotating wheel at a predetermined position, and a recognizable measurement barcode is written on the reading tape for the CCD image sensor to identify and read.

6. The automatic water level monitoring system according to claim 5, characterized in that: The recognizable measurement barcode is a 10mm×10mm code segment, including: Leading area: set at the top, used to separate adjacent coding areas. The CCD image sensor can identify the beginning of a new code segment and capture an image through the leading area; Ten-meter position identification area: set below the leading area, it is a horizontal barcode, and the ten-meter position is read by identifying the width ratio of the black and white barcodes; Centimeter position identification area: set below the ten-meter position identification area, it is three vertical bar codes, corresponding to the meter position, decimeter position, and centimeter position from one side to the other side. By identifying the ratio of the height of the black and white codes of the three vertical bar codes respectively, the centimeter position can be read; Millimeter digit precision reading area: It is set on the right side. After the leading area reads the new code segment, the CCD image sensor outputs the millimeter digit reading by capturing the overlapping part between the sighting axis and the barcode.

7. An automated water level monitoring method based on the automated water level monitoring system according to any one of claims 1 to 6, characterized in that: The steps include: Set the pull threshold F of the processor 拉 , so that it has the same gravity as the water level mark unit; The tension detection unit detects the tension value F of the water level marking unit in real time. ’ 拉 , and transmits it to the processor; The processor receives the tension value F ’ 拉 and compare it with the tension threshold F 拉 Compare and judge, and send corresponding driving instructions to the driving unit according to the judgment result: If F ’ 拉 =F 拉 , the drive unit does not work, If F ’ 拉 >F 拉 The driving unit drives the water level marking unit to be lowered until F ’ 拉 =F 拉 , the driving unit stops working, If F ’ 拉 <F 拉 The driving unit drives and lifts the water level marking unit until F ’ 拉 =F 拉 , the driving unit stops working; The reading unit reads the actual tension value F ’ 拉 With the tension threshold F 拉 The value of the water level identification unit in the consistent state determines the water level in the monitoring well.

8. An automated water level monitoring well based on buoyancy conversion elevation, characterized in that: It comprises a monitoring well unit and the automated water level monitoring system as described in any one of claims 1 to 6.

9. The automated water level monitoring well according to claim 8, characterized in that: The monitoring wells include: The bridge-type water filter pipe has at least one inwardly concave bridge-shaped gap on its pipe body to reduce the ingress of particles; An outer filter screen is covered on the outer periphery of the pipe body of the bridge type water filter pipe; A fastening steel ring is fastened to the outer filter screen at the butt connection of two adjacent upper and lower bridge-type water filter pipes to fasten the bridge-type water filter pipes.

10. The automated water level monitoring well according to claim 9, characterized in that: The bridge type water filter pipe is a socket-and-spigot type pipe body structure, and its upper end and lower end are provided with socket-and-spigot ports which match each other.

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