Multi-distance layered anti-interference open channel flow measuring device and method

Abstract

A kind of multi-distance layered anti-interference open channel flow measuring device and flow measuring method, including water channel side wall (1) and water channel bottom (2), characterized by: the two inner side wall surfaces of the water channel side wall (1) opposite are respectively provided with a plurality of strip notches (3) along the longitudinal direction, at least two strip notches (3) with a certain interval are provided on the water channel side wall (1) on one side, pre-buried mounting seat (4) is respectively fixed in strip notch (3), the side of arc-shaped insertion slot (7) close to ditch water body is set as open face, flow measuring unit is respectively installed in arc-shaped insertion slot (7), a plurality of flow measuring sensors (16) are installed in flow measuring unit along different water level height interval, the algorithm of the present application is reasonable, processing speed is fast, can adapt to long time outdoor real-time detection, avoid the influence of water temperature on detection progress, reduce the influence of main factors such as machinery, time delay on the measurement of flow velocity, the measurement accuracy has been significantly improved.

Description

TECHNICAL FIELD

[0001] The application relates to an open channel flow measuring device and a flow measuring method, in particular to a multi-distance layered anti-interference open channel flow measuring device and a flow measuring method, and belongs to the technical field of hydrological flow measurement. BACKGROUND

[0002] China is a large agricultural country, and most of the total water consumption is used for agricultural irrigation. Water resource shortage has seriously hindered the development of modern agriculture in China. In order to better realize the water measurement in irrigation areas, the best way is to combine scientific measurement and accurate monitoring, improve the construction level of informationization in irrigation areas, scientifically and reasonably use water resources, and reduce water resource waste. The water measurement technology research in irrigation areas in China is relatively short, so there are many problems in the actual application of open channel flow measurement. There are various types of flow measuring devices, and most of the existing flow measuring devices are mainly flowmeters with high flow measurement accuracy, but most of them are expensive and have low automation degree, and cannot realize long-time monitoring of data. Especially for the water measurement equipment taking weirs, channels and water channels as the main objects, the working environment is the outdoor harsh natural environment, and the flow measuring device has the problems of difficult installation, aging and deformation in the use process, which are not conducive to the modernization construction of agricultural irrigation areas.

[0003] In addition, although there are many open channel flow measuring methods at present, they all have their own limitations and cannot well meet the current requirements of water measurement equipment such as measurement accuracy, convenience, cost and various factors. The existing flow measuring device has low flow measuring progress, and the water temperature and different water flow velocities in different water layers in the irrigation water channel will affect the detection accuracy. For example, due to the geometric characteristics of the water channel, the water flow velocities at the bottom, middle and top of the water channel are different, especially in the case of mixing a large amount of silt, bubbles and turbulence, the detection accuracy is greatly reduced. For a long time, how to accurately measure the flow and reduce the interference factors has been a universal technical problem in the field. A scientific and reasonable flow measuring method has been lacked to solve the above technical problems. SUMMARY

[0004] The first object of the application is to solve the defects and deficiencies of the existing water channel flow measuring device, such as difficult outdoor open channel installation, easy aging and deformation in the use process in the outdoor natural environment, inability to realize long-time real-time monitoring and high price. The application provides a multi-distance layered anti-interference open channel flow measuring device which has reasonable structure, low cost, easy installation, improved anti-interference and anti-aging performance and can realize long-time real-time monitoring.

[0005] The second object of the present application is to overcome the defects and shortcomings of the prior art, that is, the poor accuracy of the outdoor open channel method, the great influence of water temperature, sediment, bubbles, turbulence and other factors, the different water layer flow rates at different depths of the water channel, and the inability to achieve relatively accurate measurement.

[0006] To achieve the first object of the application, the technical solution of the present application is a multi-distance layered anti-interference open channel flow measuring device, comprising a water channel side wall and a water channel bottom, the two inner side wall surfaces of the water channel side wall opposite to each other are respectively provided with a plurality of strip-shaped notches along the longitudinal direction, at least two strip-shaped notches are provided on one side of the water channel side wall, a pre-buried mounting seat is fixedly arranged in each strip-shaped notch, an arc-shaped insertion slot is provided on the side close to the water body of the ditch, a flow measuring unit is arranged in each arc-shaped insertion slot, and a plurality of flow measuring sensors are arranged in the flow measuring unit at different water level intervals.

[0007] Further, two strip-shaped notches are provided on the inner wall of one side of the water channel side wall at a certain interval, a first flow measuring unit is arranged in one of the strip-shaped notches, and a second flow measuring unit is arranged in the other strip-shaped notch, and a third flow measuring unit is arranged in a strip-shaped notch provided on the inner wall of the other side of the water channel side wall.

[0008] Further, the pre-buried mounting seat comprises a bottom plate, an outer arc surface and an arc-shaped insertion slot, the bottom plate is located on the inner side of the strip-shaped notch, the outer arc surfaces are symmetrically fixed on both sides of the bottom plate, and the arc-shaped insertion slot is arranged between the two outer arc surfaces.

[0009] Further, the flow measuring unit comprises an arc surface sensor shell, a sensor mounting cavity, an end sealing member and a plurality of flow measuring sensors, the arc surface sensor shell is a long strip-shaped cavity structure with an open end, the sensor mounting cavity is arranged in the arc surface sensor shell, and the open end of the arc surface sensor shell is sealed by the end sealing member.

[0010] Further, a plurality of sensor detection holes are formed in the outer wall of the arc surface sensor shell corresponding to the open face of the arc-shaped insertion slot, the flow measuring sensors are arranged in the sensor mounting cavity, and the detection ends of the flow measuring sensors are located in the sensor detection holes.

[0011] Further, a sensor clamping and fixing groove corresponding to the sensor detection hole is arranged on the inner wall of the sensor mounting cavity, and the flow measuring sensor is fixed on the sensor clamping and fixing groove.

[0012] Further, the flow sensor is an ultrasonic transducer or a radar flow sensor.

[0013] To achieve the second object of the present application, the technical solution of the present application is a flow measuring method using a multi-distance layered anti-interference open channel flow measuring device, comprising the following steps:

[0014] A. First, connect more than three flow measuring units, check the waterproof sealing condition, and establish electrical connection between the flow measuring units and the controllers on the banks of the water channel;

[0015] B. Then, sequentially insert and install the flow measuring units in the pre-buried mounting seats, adjust the angles of the flow measuring units according to the detection requirements of the flow measuring sensors, and meet the mutual shooting requirements of the multiple flow measuring units;

[0016] C. Then, measure the distance parameter L of the equipment through the flow measuring units in the air without water flow between the flow measuring units on both banks;

[0017] D. Obtain the attitude difference of the measuring points through the attitude sensor integrated in the flow measuring unit, calculate the specific 3D coordinate positions of the flow measuring sensors for different depth detection signals or detection wave transceivers through 3D attitude analysis, and further obtain the accurate distances between the flow measuring sensors at each measuring point in the flow measuring unit;

[0018] E. Since the flow velocities of each layer of the open channel are quite different, then use layered measurement to obtain the flow velocities Vi of each water layer, i∈M, from top to bottom;

[0019] F. Then, through the sound velocity elimination algorithm, weaken the influence of sound velocity in measurement, avoid the serious influence of sound velocity in the presence of silt, and make the measurement error too large;

[0020] G. Finally, calculate the area of the water layer Si=f(L,K,P) through the distance K of the flow measuring sensor on the split type measuring device and the attitude quaternion data P (w,x,y,z) of the transceiving equipment, and calculate the relatively accurate cumulative flow according to the sampling interval ΔT and the total measurement time T.

[0021] Further, the sound velocity elimination algorithm in step F is as follows:

[0022] When the ultrasonic wave is incident from probe A, the following relationship exists when the ultrasonic wave is received at probe B:

[0023]

[0024] When the ultrasonic wave is incident from probe B, the following relationship exists when the ultrasonic wave is received at probe A:

[0025]

[0026] Subtracting the above two equations, we get:

[0027]

[0028] It can be seen that the expression of flow rate v no longer contains the ultrasonic wave speed c.

[0029] Further, the algorithm formula in the G step is:

[0030]

[0031] In the formula, ΔQj is the flow at any time, is the average flow rate at any time.

[0032] The beneficial effects of the present application are:

[0033] 1、The present application has a strip-shaped notch on the surface of the existing water channel and installs a pre-buried mounting seat, or the pre-buried mounting seat is directly pre-buried, which provides convenience for installing a modularized sensor device, and the pre-buried mounting seat can well protect the sensor shell and is less affected by external factors such as silt, sundries, and exposure, is not easy to deform, and has good anti-aging performance.

[0034] 2、The present application adopts multiple groups of flow measurement units, is convenient to install and angle adjust, has strong anti-interference performance, and through a posture sensor integrated in the flow measurement unit, can accurately obtain posture differences of measurement points, solves specific 3D coordinate positions of the flow measurement sensor for different depth detection signals or detection wave transceivers through 3D posture analysis, and further obtains accurate distances between the flow measurement sensors of the measurement points in the flow measurement unit.

[0035] 3、The present application builds an ultrasonic cross-section flow rate measurement model and a flow measurement noise reduction model, inserts a flow rate-area water measurement intelligent algorithm, avoids the influence of water temperature on detection progress through a sound speed elimination algorithm, simultaneously reduces the influence of main factors such as machinery and time delay on flow rate measurement, and the measurement precision is significantly improved. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 is a cross-section structure schematic diagram of the water channel to which the present application is installed.

[0037] Figure 2 is a schematic diagram of the pre-buried mounting seat installed on the water channel.

[0038] Figure 3 is a structure schematic diagram of the pre-buried mounting seat.

[0039] Figure 4It is the structural schematic diagram of the first embodiment of the cambered surface sensor shell of the application.

[0040] Figure 5 It is the structural schematic diagram of the cambered surface sensor shell of the application.

[0041] Figure 6 It is the internal structural schematic diagram of the cambered surface sensor shell of the application.

[0042] Figure 7 It is the schematic diagram of the first embodiment of the cambered surface sensor shell of the application installed on the pre-embedded mounting seat.

[0043] Figure 8 It is the structural schematic diagram of the second embodiment of the cambered surface sensor shell of the application.

[0044] Figure 9 It is the schematic diagram of the second embodiment of the cambered surface sensor shell of the application installed on the pre-embedded mounting seat.

[0045] Figure 10 It is the measurement principle schematic diagram of the application.

[0046] Figure 11 It is the measurement principle schematic diagram of multiple measurement points of the application.

[0047] In the figure: water channel side wall 1, water channel bottom 2, strip-shaped notch 3, pre-embedded mounting seat 4, bottom plate surface 5, outer side arc surface 6, arc-shaped plug-in slot 7, No. 1 flow measurement unit 8, No. 2 flow measurement unit 9, No. 3 flow measurement unit 10, cambered surface sensor shell 11, sensor mounting cavity 12, end sealing element 13, sensor detection hole 14, sensor clamping and fixing slot 15, flow measurement sensor 16, adjustable toothed disc 17, fixing ring 18. DETAILED DESCRIPTION

[0048] The application is further described in detail in the following description and specific embodiments in conjunction with the accompanying drawings.

[0049] Referring to Figures 1 to 11 The application is a multi-distance layered anti-interference open channel flow measurement device, which comprises a water channel side wall 1 and a water channel bottom 2, characterized in that: two inner side wall surfaces of the water channel side wall 1 opposite to each other are respectively provided with a plurality of strip-shaped notches 3 along the longitudinal direction, at least two strip-shaped notches 3 with a certain interval are provided on one side of the water channel side wall 1, a pre-embedded mounting seat 4 is fixedly arranged in each strip-shaped notch 3, an arc-shaped plug-in slot 7 is provided as an open surface on the side close to the water body, a flow measurement unit is installed in the arc-shaped plug-in slot 7, and a plurality of flow measurement sensors 16 are installed in the flow measurement unit at different water level intervals.

[0050] Two strip-shaped slots 3 are provided on the inner wall of one side of the canal side wall 1 at a certain interval, wherein a No. 1 flow measuring unit 8 is installed in one of the strip-shaped slots 3, and a No. 2 flow measuring unit 9 is installed in the other strip-shaped slot 3. A strip-shaped slot 3 is provided on the inner wall of the other side of the canal side wall 1, and a No. 3 flow measuring unit 10 is installed in the strip-shaped slot 3. The No. 3 flow measuring unit 10 is respectively arranged corresponding to the No. 1 flow measuring unit 8 and the No. 2 flow measuring unit 9.

[0051] The embedded mounting seat 4 includes a bottom plate surface 5, an outer arcuate surface 6 and an arcuate plug-in groove 7. The bottom plate surface 5 is located on the inner side of the strip-shaped slot 3. The outer arcuate surfaces 6 are symmetrically fixed on both sides of the bottom plate surface 5, and an arcuate plug-in groove 7 is provided between the two outer arcuate surfaces 6.

[0052] The flow measuring unit includes a curved surface sensor housing 11, a sensor mounting cavity 12, an end seal 13 and multiple flow measuring sensors 16. The curved surface sensor housing 11 is a long strip-shaped cavity structure with one end open. The interior of the curved surface sensor housing 11 is provided with a sensor mounting cavity 12, and the open end of the curved surface sensor housing 11 is sealed by an end seal 13.

[0053] The outer wall of the arc sensor housing 11 is provided with a plurality of sensor detection holes 14 corresponding to the open surface of the arc-shaped plug-in slot 7 . A flow measuring sensor 16 is installed in the sensor installation cavity 12 , and the detection end of the flow measuring sensor 16 is located in the sensor detection hole 14 .

[0054] An adjustable toothed disc 17 is fixedly provided at the upper end of the arc surface sensor housing 11 , and a fixing ring 18 with a gear ring is fixedly provided at the upper end of the arc-shaped plug-in slot 7 . The gear ring on the fixing ring 18 cooperates with the tooth structure on the adjustable toothed disc 17 .

[0055] A sensor clamping and fixing groove 15 corresponding to the sensor detection hole 14 is provided on the inner wall of the sensor installation cavity 12 , and a flow measuring sensor 16 is fixed on the sensor clamping and fixing groove 15 .

[0056] The flow measuring sensor 16 is an ultrasonic transducer or a radar flow measuring sensor.

[0057] A flow measurement method using a multi-distance layered anti-interference open channel flow measurement device comprises the following steps:

[0058] A. First, connect three or more flow measuring units, check the waterproof seal, and establish electrical connections between the flow measuring units and the controllers on the bank of the canal;

[0059] B. Then, plug and install the flow measuring units in the pre-buried mounting bases one by one, and adjust the angles of the flow measuring units according to the detection requirements of the flow measuring sensors to meet the requirements of the two-to-two cross-reflection of multiple flow measuring units;

[0060] C. Then the distance parameter L of the device is measured by the flow measurement unit in the air without water between the two flow measurement units on both sides;

[0061] D. The attitude difference of the measurement point is obtained by the attitude sensor integrated in the flow measurement unit, and the specific 3D coordinate position of the flow sensor for different depth detection signals or detection wave transceivers is calculated by 3D attitude analysis, and the accurate distance between the flow sensors of each measurement point in the flow measurement unit is further obtained;

[0062] E. Since the flow rate of each layer of the open channel is quite different, the flow rate Vi of each water layer is obtained by layering, i∈M, from top to bottom, and the water layer number is obtained.

[0063] F. Then the influence of sound velocity in measurement is weakened by the sound velocity elimination algorithm, and the influence of silt on sound velocity is avoided, so that the measurement error is too large.

[0064] G. Finally, the area Si of the water layer is calculated by the distance K of the flow sensor on the split type measuring device and the attitude quaternion data P (w, x, y, z) of the transceiver device, Si=f(L, K, P), and the relatively accurate cumulative flow can be calculated according to the sampling interval ΔT and the total measurement time T.

[0065] The sound velocity elimination algorithm in the F step is as follows:

[0066] When the ultrasonic wave is incident from the probe A, the ultrasonic wave is received at the probe B, and the following relationship exists:

[0067]

[0068] When the ultrasonic wave is incident from the probe B, the ultrasonic wave is received at the probe A, and the following relationship exists:

[0069]

[0070] The above two formulas are subtracted to obtain:

[0071]

[0072] It can be seen that the expression of the flow rate v no longer contains the ultrasonic wave velocity c.

[0073] The algorithm formula in the G step is:

[0074]

[0075] In the formula, ΔQj is the flow at any time, is the average flow rate at any time.

[0076] Referring to Figures 1 to 5The application can adapt to long-time outdoor real-time detection, avoids the influence of water temperature on detection progress, and reduces the influence of main factors such as machinery and time delay on flow velocity measurement. The application adopts a multi-distance layered anti-interference open channel flow measuring device, and scientifically and ingeniously builds an ultrasonic cross-section flow velocity measuring model and a flow measuring noise reduction model, and inserts a flow velocity-area water measuring method intelligent algorithm, and avoids the influence of water temperature on detection progress through a sound velocity elimination algorithm. The specific method steps and principles are as follows:

[0077] The application is characterized in that a plurality of strip-shaped notches 3 are longitudinally arranged on the side wall of the water channel, water tank or other open channel agricultural irrigation facilities, at least two strip-shaped notches 3 are arranged on one side of the water channel side wall 1 at a certain interval. One set of open channel flow measuring device is generally provided with not less than three strip-shaped notches 3, the strip-shaped notches 3 are used for installing the pre-embedded mounting seat 4, and the strip-shaped notches 3 can be pre-embedded during construction or can be slotted on site during installation. The pre-embedded mounting seat 4 is fixedly arranged in the strip-shaped notch 3, and the pre-embedded mounting seat 4 can be made of a whole stainless steel or aluminum alloy component, is effectively connected and fixed with the surface of the water channel and other water conservancy facilities, the connection part is smoothly transitioned, and stability can be ensured under the action of water flow.

[0078] The pre-embedded mounting seat 4 can adopt various structure forms, and the structure with an arc-shaped insertion groove is preferred. Specifically, the pre-embedded mounting seat 4 comprises a bottom plate surface 5, an outer arc surface 6 and an arc-shaped insertion groove 7, and the bottom plate surface 5, the outer arc surface 6 and the arc-shaped insertion groove 7 are fixed as a whole and can be processed by casting or welding. The cross-sectional contour of the pre-embedded mounting seat 4 is the same as that of the strip-shaped notch 3. The bottom plate surface 5 is located on the inner side of the strip-shaped notch 3, and the outer arc surfaces 6 are symmetrically arranged on both sides of the bottom plate surface 5. The arc-shaped insertion groove 7 is arranged between the two outer arc surfaces 6, and the connection part between the two outer arc surfaces 6 and the bottom plate surface 5 is smoothly connected with the water channel side wall 1.

[0079] The arc-shaped insertion groove 7 is respectively installed with a flow measuring unit. Taking a set of open channel flow measuring device provided with three flow measuring units as an example, the three flow measuring units are respectively denoted as a first flow measuring unit 8, a second flow measuring unit 9 and a third flow measuring unit 10. Therefore, two strip-shaped notches 3 are arranged on the inner wall of one side of the water channel side wall 1 at a certain interval, one of the two strip-shaped notches 3 is installed with the first flow measuring unit 8, and the other strip-shaped notch 3 is installed with the second flow measuring unit 9. One strip-shaped notch 3 is arranged on the inner wall of the other side of the water channel side wall 1, and the third flow measuring unit 10 is installed in the strip-shaped notch 3. The third flow measuring unit 10 is correspondingly arranged with the first flow measuring unit 8 and the second flow measuring unit 9.

[0080] The arc-shaped insertion slot 7 is provided with strip-shaped notches distributed along the length direction, that is, the side of the arc-shaped insertion slot 7 close to the ditch water body is provided as an open surface, the arc-shaped sensor shell 11 is installed in the arc-shaped insertion slot 7, and the stability after fixing is good. The radius of the circular arc of the arc-shaped insertion slot 7 is the same as the radius of the outer circular arc of the arc-shaped sensor shell 11, and the arc-shaped sensor shell 11 can rotate by a certain angle after being installed in the arc-shaped insertion slot 7, so as to adjust the orientation of the sensor.

[0081] The arc-shaped sensor shell 11 is a long strip-shaped cavity structure with one end open, the inside of the arc-shaped sensor shell 11 is provided as a sensor installation cavity 12 for installing the sensor. A plurality of sensor detection holes 14 are formed in the outer wall of the arc-shaped sensor shell 11 corresponding to the open surface of the arc-shaped insertion slot 7, a plurality of sensor clamping fixing grooves 15 are arranged on the inner wall of the arc-shaped sensor shell 11, a flow measuring sensor 16 is fixed on the sensor clamping fixing groove 15, the flow measuring sensor 16 adopts an ultrasonic transducer, a radar flow measuring sensor or other sensors, and the detection end of the flow measuring sensor 16 is located in the sensor detection hole 14. At the same time, the sensor installation cavity 11 is effectively sealed, the bottom end of the arc-shaped sensor shell 11 is closed or sealed by the end sealing element 13, and the upper end of the arc-shaped sensor shell 11 is also sealed by the end sealing element 13, so as to ensure good waterproof performance, and the anti-interference and anti-aging performance are also improved.

[0082] In addition, in order to facilitate the fixing of the arc-shaped sensor shell and the adjustment of a certain angle according to needs, the present application adopts the structure of toothed disc and toothed ring, the upper end of the arc-shaped sensor shell 11 is fixedly provided with an adjustable toothed disc 17, the upper end of the arc-shaped insertion slot 7 is fixedly provided with a fixed ring 18 with a tooth ring, the tooth ring on the fixed ring 18 cooperates with the tooth structure on the adjustable toothed disc 17, after the arc-shaped sensor shell 11 and the adjustable toothed disc 17 rotate by a certain angle, the fixing can be realized through the clamping between the adjustable toothed disc 17 and the fixed ring 18, and the adjustment according to needs is facilitated.

[0083] The method of the present application will be described in detail in combination with the specific embodiments as follows:

[0084] Taking three flow measuring units as an example, first, connect the three flow measuring units, check the waterproof sealing condition, and establish an electrical connection between the flow measuring units and the controller on the bank of the water channel. Then, sequentially insert and install the flow measuring units in the pre-buried mounting seat, adjust the angle of the flow measuring unit according to the detection requirements of the flow sensor, and meet the two-way shooting requirements of multiple flow measuring units. Then, the distance parameter L of the equipment is measured in the air without flowing water between the flow measuring units on both banks. The attitude difference of the measuring points is obtained through the attitude sensor integrated in the flow measuring unit, and the specific 3D coordinate position of the flow sensor for different depth detection signals or detection wave transceivers is calculated through 3D attitude analysis, and the accurate distance between the flow sensors of each measuring point in the flow measuring unit is further obtained. Since the flow velocity of each layer of the open channel is quite different, then the flow velocity Vi of each water layer is obtained by layer-by-layer measurement, i∈M, from top to bottom.

[0085] In order to eliminate the influence of ultrasonic wave velocity c on the measurement result of the to-be-measured fluid velocity v, the sound velocity elimination algorithm is used to weaken the influence of sound velocity in measurement, avoid the serious influence of sound velocity in the presence of silt, and effectively prevent the measurement error from being too large. The sound velocity elimination algorithm is as follows:

[0086] When the ultrasonic wave is incident from the probe A, the ultrasonic wave is received at the probe B, and the following relationship exists:

[0087]

[0088] When the ultrasonic wave is incident from the probe B, the ultrasonic wave is received at the probe A, and the following relationship exists:

[0089]

[0090] Subtracting the above two formulas gives:

[0091]

[0092] It can be seen that the expression of the flow velocity v no longer contains the ultrasonic wave velocity c, so as to avoid the interference of the change of the ultrasonic wave velocity c caused by the influence of temperature on the measurement result, greatly improve the accuracy of the related ultrasonic wave measurement data, and ensure the measurement accuracy.

[0093] In addition, the calculation formula of the sound velocity can be expressed by the sound pressure, that is, the sound pressure (p) 2 = sound intensity (I) x medium density (p) x sound velocity (C). Wherein, the sound intensity unit is W / m 2 , the density unit is kg / m 3 , and the sound velocity is m / s;

[0094] Adaptive filter sound velocity elimination algorithm: according to the statistical characteristics of the input signal automatically adjust the parameters of the filter. In flow measurement, the adaptive filter algorithm can be used to filter out the noise signal caused by the change of sound velocity or interference frequency component, improve the accuracy of flow signal.

[0095] First, take the first layer of the rectangular pipe of the measurement section as an example. In a group of ultrasonic transducers, the first ultrasonic transducer emits sound waves reflected to the second ultrasonic transducer through the reflection plane, and the transmission time t of the sound wave along the gas flow direction is collected ab ; The second ultrasonic transducer emits sound waves reflected to the first ultrasonic transducer through the reflection plane, and the transmission time t of the sound wave against the gas flow direction is collected. Then list the relationship between the propagation time and the flow velocity v, and eliminate the sound velocity c after association to get the formula of the flow velocity v as follows:

[0096]

[0097] Where l is the distance from the ultrasonic transducer to the reflection point, and a is the angle between the ultrasonic propagation direction and the horizontal direction. Finally, according to the above method, the flow velocities Vi of the multiple layers of rectangular pipes are measured, and the estimated value of the average flow velocity of the pipe is obtained by using the mathematical function relationship. Multiply the flow area A of the measurement section, and the final flow Q can be obtained. The formula is: Q=VA, where k is less than or equal to the number of layers of the rectangular pipe.

[0098] Finally, the area of the water layer Si=f(L,K,P) is calculated through the distance K of the flow sensor on the split type measuring device and the attitude quaternion data P (w,x,y,z) of the transceiver equipment. According to the sampling interval ΔT and the total measurement time T, the relatively accurate cumulative flow Q can be calculated.

[0099] The average flow velocity at any time is:

[0100]

[0101] The average flow at any time is: ;

[0102] Since the total sampling number is:

[0103]

[0104] Therefore, the total flow is:

[0105]

[0106] Considering that there is a large integral error in rectangular integration, the formula can be modified as:

[0107]

[0108] The application maximizes the flow velocity detection precision, reduces the influence of main factors such as machinery and time delay on the flow velocity measurement, and significantly improves the measurement precision by building an ultrasonic cross-section flow velocity measurement model and a flow measurement noise reduction model and placing a flow velocity-area water measurement intelligent algorithm.

[0109] The above is a further detailed description of the application made in combination with the specific embodiments, and cannot be considered as limiting the specific embodiments of the application to these descriptions. Simple modifications and replacements made by those skilled in the art without departing from the concept of the application should be considered as belonging to the protection scope of the application.

Claims

1. A flow measurement method for a multi-distance layered anti-interference open channel flow measurement device, comprising the following steps: A. First, connect three or more flow measuring units, check the waterproof seal, and establish electrical connections between the flow measuring units and the controllers on the bank of the canal; B. Then, plug and install the flow measuring units in the pre-buried mounting bases one by one, and adjust the angles of the flow measuring units according to the detection requirements of the flow measuring sensors to meet the requirements of the two-to-two cross-reflection of multiple flow measuring units; C. Then, the distance parameter L of the device is measured by the flow measuring unit in the air without water flow between the flow measuring units on both sides; D. Using the attitude sensors integrated in the flow measurement units, the attitude differences of the flow measurement sensors are obtained. The specific 3D coordinate positions of the flow measurement sensors in each flow measurement unit are calculated through 3D attitude analysis, and the precise distances between the flow measurement sensors in the flow measurement units are further obtained. E. Since the flow velocity of each layer in the open channel is quite different, the flow velocity of each water layer Vi is obtained by layered measurement, i∈M, and the water layers are numbered from top to bottom; F. Then, the sound velocity elimination algorithm is used to weaken the influence of sound velocity in the measurement, so as to avoid the serious influence of sound velocity in the presence of sediment, which would cause excessive measurement error. G. Finally, the area of ​​the water layer Si=f(L,K,P) is calculated through the spacing K of the flow measuring sensors and the attitude quaternion data P (w,x,y,z) of the flow measuring sensors. The relatively accurate cumulative flow rate can be calculated based on the sampling interval ΔT and the total metering time T.

2. The flow measurement method of the multi-distance layered anti-interference open channel flow measurement device according to claim 1, characterized in that: The specific algorithm for eliminating the speed of sound term in step F is as follows: When ultrasonic waves are incident from probe A and received by probe B, the following relationship holds: When ultrasonic waves are incident from probe B and received by probe A, the following relationship exists: Subtracting the above two equations, we get: It can be seen that the expression of flow velocity v no longer contains the ultrasonic wave velocity c.

3. The flow measurement method of the multi-distance layered anti-interference open channel flow measurement device according to claim 1, characterized in that: The algorithm formula in the G step is: Where ΔQj is the flow rate at any time, is the average flow velocity at any time.

4. A multi-distance layered anti-interference open channel flow measurement device using the flow measurement method according to claim 1, comprising a channel sidewall (1) and a channel bottom (2), characterized in that: The inner wall surfaces of the two opposing canal side walls (1) are respectively provided with a plurality of strip-shaped notches (3) along the longitudinal direction, wherein the canal side wall (1) located on one side is provided with at least two strip-shaped notches (3) spaced at a certain interval, and embedded mounting seats (4) are respectively fixedly provided in the strip-shaped notches (3), and the side of the arc-shaped plug-in groove (7) close to the canal water body is provided with an open surface, and flow measuring units are respectively installed in the arc-shaped plug-in groove (7), and a plurality of flow measuring sensors (16) are installed in the flow measuring units at intervals along different water levels.

5. The multi-distance layered anti-interference open channel flow measurement device according to claim 4, characterized in that: Two strip-shaped slots (3) are provided on the inner wall of one side of the canal side wall (1) at a certain interval, wherein a No. 1 flow measuring unit (8) is installed in one of the strip-shaped slots (3), and a No. 2 flow measuring unit (9) is installed in the other strip-shaped slot (3). A strip-shaped slot (3) is provided on the inner wall of the other side of the canal side wall (1), and a No. 3 flow measuring unit (10) is installed in the strip-shaped slot (3). The No. 3 flow measuring unit (10) is respectively provided corresponding to the No. 1 flow measuring unit (8) and the No. 2 flow measuring unit (9).

6. The multi-distance layered anti-interference open channel flow measurement device according to claim 4, characterized in that: The embedded mounting seat (4) comprises a bottom plate surface (5), an outer arcuate surface (6) and an arcuate plug-in groove (7), wherein the bottom plate surface (5) is located on the inner side of the strip-shaped notch (3), the outer arcuate surfaces (6) are symmetrically fixedly provided on both sides of the bottom plate surface (5), and the arcuate plug-in groove (7) is provided between the two outer arcuate surfaces (6).

7. The multi-distance layered anti-interference open channel flow measurement device according to claim 4, characterized in that: The flow measuring unit comprises a curved surface sensor housing (11), a sensor mounting cavity (12), an end sealing member (13), and a plurality of flow measuring sensors (16). The curved surface sensor housing (11) is a long strip-shaped cavity structure with one end open. The sensor mounting cavity (12) is provided inside the curved surface sensor housing (11), and the open end of the curved surface sensor housing (11) is sealed by the end sealing member (13).

8. The multi-distance layered anti-interference open channel flow measurement device according to claim 7, characterized in that: The outer wall of the arc-shaped sensor housing (11) is provided with a plurality of sensor detection holes (14) corresponding to the open surface of the arc-shaped plug-in slot (7), a flow measuring sensor (16) is installed in the sensor installation cavity (12), and a detection end of the flow measuring sensor (16) is located in the sensor detection hole (14).

9. The multi-distance layered anti-interference open channel flow measurement device according to claim 7, characterized in that: A sensor clamping and fixing groove (15) corresponding to the sensor detection hole (14) is provided on the inner wall of the sensor installation cavity (12), and a flow measuring sensor (16) is fixed on the sensor clamping and fixing groove (15).

10. The multi-distance layered anti-interference open channel flow measurement device according to claim 8 or 9, characterized in that: The flow measuring sensor (16) is an ultrasonic transducer or a radar flow measuring sensor.

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