Water flow rate and direction measuring device and method

Abstract

The application discloses a water flow velocity and flow direction measuring device and method. The device comprises a hollow top rod and a shell, the top rod is provided with a breather pipe and an electric wire, the breather pipe is communicated with a plurality of air bag surfaces, the shell is provided with corresponding sensing units on the outer surface, a counterweight is fixed at the bottom of the shell, and a radial magnetization permanent magnet is arranged at the ball center. During measurement, the device is put into water, the water flow impacts the elastic deformation area, the Hall element follows the change of the magnetic field to sense and output a Hall voltage signal, the voltage signals of each group of radial differential measurement pairs are subtracted, and the flow velocity and flow direction are calculated according to the spatial distribution of the differential signals. The application adopts a spherical three-dimensional omnidirectional Hall type sensing structure, integrates the flow velocity and flow direction measurement into a fully sealed probe, has no dynamic seal and mechanical components, and can avoid the problems of abrasion and jamming, and is suitable for complex environments such as rivers, irrigation channels and pipelines.

Description

Technical Field

[0001] This invention belongs to the field of hydrological monitoring technology, and relates to a device for measuring water flow velocity and direction, as well as a method for measuring water flow velocity and direction. Background Technology

[0002] In long-term unattended scenarios such as field hydrological monitoring, farmland irrigation metering, and water supply and drainage pipeline flow detection, traditional propeller-type current meters rely on mechanical shafts and bearing structures. Silt, aquatic plants, and suspended solids in natural river channels can easily become entangled and jam the rotating components, leading to excessively high starting flow rates or even operational failure. Furthermore, prolonged immersion causes significant mechanical wear, which shortens the equipment's lifespan, and frequent cleaning and calibration severely restricts its reliability in practical engineering applications.

[0003] While existing Hall effect or electromagnetic current meters eliminate mechanical rotating parts, offering advantages such as low power consumption and non-contact measurement, their measurement mechanisms typically only sense the velocity component along a single axis. In areas with significant turbulence or secondary flow characteristics, such as natural river bends, tidal river sections, and downstream of pipe bends, they cannot capture true three-dimensional velocity vector information, leading to missing flow direction identification and significant deviations between flow measurement results and actual values. Furthermore, existing high-precision current meters are subject to strict constraints on installation posture, requiring precise vertical or horizontal calibration with the aid of tools to ensure measurement accuracy. However, in scenarios such as field deployment, suspension, or fixation within inspection well walls, it is often difficult to maintain an ideal horizontal position, and the equipment is prone to slow tilting due to long-term water flow impact. Existing products lack effective posture compensation mechanisms; once tilted, gravity component errors are introduced, severely deteriorating the accuracy of velocity vector calculation.

[0004] Existing measurement methods are no longer sufficient to meet the dual requirements of long-term unattended operation and accurate measurement in complex flow field environments. Therefore, there is an urgent need for a water flow velocity and direction measurement device that combines three-dimensional flow field perception capability and attitude self-adaptation. Summary of the Invention

[0005] The purpose of this invention is to provide a water flow velocity and direction measuring device, which solves the problems of single measurement dimension and large attitude deviation in the prior art.

[0006] The second objective of this invention is to provide a method for measuring water flow velocity and direction.

[0007] The technical solution adopted in this invention is a water flow velocity and direction measuring device, including a top rod and a housing. The top rod is a hollow structure and its lower end is integrally formed with the top of the housing. A vent pipe and an electrical wire pass through the top rod. The vent pipe is connected to several air bladder surfaces. Several sensing units are fixed to the outer surface of the housing. Several air bladder surfaces are respectively arranged corresponding to several sensing units. A counterweight is fixed at the bottom of the housing cavity. A radially magnetized permanent magnet is provided at the center of the housing. The counterweight, the top rod and the radially magnetized permanent magnet are coaxially arranged.

[0008] The features of this invention are: The top of the top rod has an external interface, through which a vent tube and an electrical wire are threaded. The end of the vent tube away from the airbag surface is connected to an electric air pump, and one end of the electrical wire is connected to a power source. The end of the electrical wire away from the power source has a charging interface.

[0009] The shell is a spherical shell, which is formed by joining a first hemisphere and a second hemisphere. A sealing ring is provided on the mating surface of the first hemisphere and the second hemisphere. Ear plates are fixed to the outer edges of the first hemisphere and the second hemisphere respectively. Bolts are inserted between the two ear plates. The first hemisphere and the second hemisphere are fastened together by bolts.

[0010] The shell includes an elastic deformation zone and a rigid support zone, which are integrally formed. The position of the elastic deformation zone corresponds to the airbag surface.

[0011] Each sensing unit includes two rigid support walls. The bottom of the two rigid support walls is fixed to the outer surface of the housing. Several through holes are symmetrically and evenly opened on the two rigid support walls. Hall element pins are inserted into the rigid support walls. The two Hall element pins are soldered together to a Hall element. A wire hole is opened on the wall of the housing. A sealing connector is installed in the wire hole. A sealing ring is provided between the sealing connector and the housing wall. The Hall element pins are attached to and fixed to the outer wall of the housing and pass through the housing wall. The Hall element pins pass through the sealing connector and are soldered to the PCB board at the end away from the Hall element. Two elastic metal plates are provided on both sides of the Hall element. The two elastic metal plates are snapped and fixed to the top end face of the sensing unit.

[0012] Each of the first and second hemispherical shells has six uniformly distributed elastic deformation zones, each corresponding to a Hall element. Every two Hall elements arranged opposite each other form a radial differential measurement pair.

[0013] The radially magnetized permanent magnet is fixed to the top of the counterweight by a support frame. The outer surface of the radially magnetized permanent magnet is covered with a permalloy uniform magnetic sleeve. The counterweight is made of tungsten alloy.

[0014] The top inner wall of the housing has a mounting slot, in which a power supply and a PCB board are fixed. The power supply is electrically connected to the PCB board, which has a microcontroller. The microcontroller is programmed with control programs, including an air pump control program, a sensor signal receiving program, a signal processing program, and a Bluetooth communication program. The microcontroller on the PCB board is soldered to the pins of the Hall element.

[0015] Another technical solution adopted in this invention is a method for measuring water flow velocity and direction, which uses a water flow velocity and direction measuring device and includes the following steps: Step 1: Submerge the water flow velocity measuring device in the water; Step 2: The water flow impacts the elastic deformation zone, causing local deformation in the elastic deformation zone. The Hall element moves along with the elastic deformation zone and senses the change in the magnetic field of the radially magnetized permanent magnet, outputting a Hall voltage signal. Step 3: Subtract the Hall voltage signals from each radial differential measurement pair to obtain the differential signal; Step 4: Calculate the water flow velocity and direction based on the spatial distribution of all differential signals.

[0016] The invention is further characterized by: It also includes the following steps: inflating the airbag surface through the ventilator, causing the airbag surface to expand and push against the inner wall of the elastic deformation zone, and the elastic deformation zone to return to its initial spherical shape.

[0017] The beneficial effects of this invention are: This invention relates to a water flow velocity and direction measuring device, which employs a spherical three-dimensional omnidirectional Hall effect sensor structure. It integrates velocity and direction measurements into a single, fully sealed spherical probe, eliminating the need for any dynamic seals or mechanical transmission components. This fundamentally eliminates the problems of erosion, jamming, and debris entanglement in rotating parts caused by high-silt water bodies, significantly reducing failure rates and maintenance costs. Simultaneously, the streamlined spherical shape effectively reduces water flow disturbance, improves response sensitivity at low flow velocities, and possesses a smooth, self-cleaning capability, ensuring measurement stability even after long-term immersion in complex water conditions. Furthermore, the device can achieve synchronous three-dimensional omnidirectional measurement in any spatial direction, unrestricted by the direction of incoming flow. It is particularly suitable for complex environments such as natural rivers, agricultural irrigation canals, and municipal water supply and drainage pipelines, providing a maintenance-free, highly reliable, and advanced three-dimensional omnidirectional measurement method for hydrological monitoring and irrigation metering. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the water flow velocity and direction measuring device of the present invention; Figure 2 This is a schematic diagram of the sensing unit structure of the water flow velocity and direction measuring device of the present invention.

[0019] In the diagram, 1. Top rod; 2. Airbag ventilation tube; 3. Wire; 4. Sensing unit; 5. Power supply; 6. Ear plate; 7. Bolt; 8. Radial magnetized permanent magnet; 9. Counterweight; 10. Housing; 11. Hall element pin; 12. Through hole; 13. Airbag surface; 14. Hall element; 15. Elastic metal sheet; 16. Rigid support wall; 17. First hemispherical shell; 18. Second hemispherical shell. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0021] Example 1 This embodiment provides a water flow velocity and direction measuring device, such as... Figure 1As shown, it includes a push rod 1 and a housing 10. The push rod 1 has a hollow structure and its lower end is integrally formed with the top of the housing 10. A vent pipe 2 and an electric wire 3 are inserted inside the push rod 1. The vent pipe 2 is connected to several air bladder surfaces 13. Several sensing units 4 are fixed to the outer surface of the housing 10. Several air bladder surfaces 13 are respectively arranged corresponding to several sensing units 4. A counterweight 9 is fixed at the bottom of the cavity of the housing 10. A radially magnetized permanent magnet 8 is provided at the center of the housing 10. The counterweight 9, the push rod 1 and the radially magnetized permanent magnet 8 are coaxially arranged.

[0022] Example 2 This embodiment provides a water flow velocity and direction measuring device, such as... Figure 1 As shown, it includes a push rod 1 and a housing 10. The push rod 1 has a hollow structure and its lower end is integrally formed with the top of the housing 10. A vent pipe 2 and an electric wire 3 are inserted inside the push rod 1. The vent pipe 2 is connected to several air bladder surfaces 13. Several sensing units 4 are fixed to the outer surface of the housing 10. Several air bladder surfaces 13 are respectively arranged corresponding to several sensing units 4. A counterweight 9 is fixed at the bottom of the cavity of the housing 10. A radially magnetized permanent magnet 8 is provided at the center of the housing 10. The counterweight 9, the push rod 1 and the radially magnetized permanent magnet 8 are coaxially arranged.

[0023] The top of the top rod 1 has an external interface, through which a vent pipe 2 and an electrical wire 3 are threaded. The end of the vent pipe 2 away from the airbag surface 13 is connected to an electric air pump, and one end of the electrical wire 3 is connected to a power source 5. The end of the electrical wire 3 away from the power source 5 has a charging interface, which can be plugged into and grounded to charge the power source 5. The top of the top rod 1 also has a mounting structure for fixing it to an external support, survey vessel, cableway, buoy, or survey platform. The top rod 1 serves as both a mounting structure and, through its internal cavity, as a conduit for the air pipe 2 and electrical wire 3. The external interface is located at the top of the top rod 1, avoiding the need for openings on the surface of the housing 10 to maintain its sealing integrity. The top rod 1 has a multi-section nested structure, with locking mechanisms between each section. The overall length of the top rod 1 can be adjusted by telescoping to change the depth at which the housing 10 is submerged below the water surface.

[0024] Example 3 This embodiment provides a water flow velocity and direction measuring device, such as... Figure 1 As shown, it includes a push rod 1 and a housing 10. The push rod 1 has a hollow structure and its lower end is integrally formed with the top of the housing 10. A vent pipe 2 and an electric wire 3 are inserted inside the push rod 1. The vent pipe 2 is connected to several air bladder surfaces 13. Several sensing units 4 are fixed to the outer surface of the housing 10. Several air bladder surfaces 13 are respectively arranged corresponding to several sensing units 4. A counterweight 9 is fixed at the bottom of the cavity of the housing 10. A radially magnetized permanent magnet 8 is provided at the center of the housing 10. The counterweight 9, the push rod 1 and the radially magnetized permanent magnet 8 are coaxially arranged.

[0025] The top of the top rod 1 has an external interface, through which a vent pipe 2 and an electrical wire 3 are threaded. The end of the vent pipe 2 away from the airbag surface 13 is connected to an electric air pump, and one end of the electrical wire 3 is connected to a power source 5. The end of the electrical wire 3 away from the power source 5 has a charging interface. The top of the top rod 1 also has a mounting structure for fixing it to an external support, survey vessel, cableway, buoy, or survey platform. The top rod 1 serves as both a mounting structure and its internal cavity as a conduit for the air pipe 2 and electrical wire 3. The external interface is located at the top of the top rod 1, avoiding the need for openings on the surface of the housing 10 to maintain its sealing integrity. The top rod 1 has a multi-section nested structure, with locking mechanisms between each section. The overall length of the top rod 1 can be adjusted by telescoping to change the depth to which the housing 10 is submerged below the water surface.

[0026] The shell 10 is a spherical shell, which is formed by joining a first hemispherical shell 17 and a second hemispherical shell 18. A sealing ring is provided on the mating surface of the first hemispherical shell 17 and the second hemispherical shell 18. Ear plates 6 are fixedly connected to the outer edges of the first hemispherical shell 17 and the second hemispherical shell 18 respectively. Bolts 7 are passed between the two ear plates 6. The first hemispherical shell 17 and the second hemispherical shell 18 are relatively fastened together by bolts 7.

[0027] The shell 10 includes an elastic deformation region and a rigid support region. The elastic deformation region and the rigid support region are integrally formed. The position of the elastic deformation region corresponds to the airbag surface 13.

[0028] Example 4 This embodiment provides a water flow velocity and direction measuring device, such as... Figure 1 As shown, it includes a push rod 1 and a housing 10. The push rod 1 has a hollow structure and its lower end is integrally formed with the top of the housing 10. A vent pipe 2 and an electric wire 3 are inserted inside the push rod 1. The vent pipe 2 is connected to several air bladder surfaces 13. Several sensing units 4 are fixed to the outer surface of the housing 10. Several air bladder surfaces 13 are respectively arranged corresponding to several sensing units 4. A counterweight 9 is fixed at the bottom of the cavity of the housing 10. A radially magnetized permanent magnet 8 is provided at the center of the housing 10. The counterweight 9, the push rod 1 and the radially magnetized permanent magnet 8 are coaxially arranged.

[0029] The top of the top rod 1 has an external interface, through which a vent pipe 2 and an electrical wire 3 are threaded. The end of the vent pipe 2 away from the airbag surface 13 is connected to an electric air pump, and one end of the electrical wire 3 is connected to a power source 5. The end of the electrical wire 3 away from the power source 5 has a charging interface. The top of the top rod 1 also has a mounting structure for fixing it to an external support, survey vessel, cableway, buoy, or survey platform. The top rod 1 serves as both a mounting structure and its internal cavity as a conduit for the air pipe 2 and electrical wire 3. The external interface is located at the top of the top rod 1, avoiding the need for openings on the surface of the housing 10 to maintain its sealing integrity. The top rod 1 has a multi-section nested structure, with locking mechanisms between each section. The overall length of the top rod 1 can be adjusted by telescoping to change the depth to which the housing 10 is submerged below the water surface.

[0030] The shell 10 is a spherical shell, which is formed by joining a first hemispherical shell 17 and a second hemispherical shell 18. A sealing ring is provided on the mating surface of the first hemispherical shell 17 and the second hemispherical shell 18. Ear plates 6 are fixedly connected to the outer edges of the first hemispherical shell 17 and the second hemispherical shell 18 respectively. Bolts 7 are passed between the two ear plates 6. The first hemispherical shell 17 and the second hemispherical shell 18 are relatively fastened together by bolts 7.

[0031] The shell 10 includes an elastic deformation region and a rigid support region. The elastic deformation region and the rigid support region are integrally formed. The position of the elastic deformation region corresponds to the airbag surface 13.

[0032] like Figure 2 As shown, each sensing unit 4 includes two rigid support walls 16. The bottom of the two rigid support walls 16 is fixed to the outer surface of the housing 10. Several through holes 12 are symmetrically and evenly opened on the two rigid support walls 16. Hall element pins 11 are passed through the rigid support walls 16. The two Hall element pins 11 are welded together to the Hall element 14. The wall surface of the housing 10 is provided with a wire hole. A sealing connector is provided in the wire hole. A sealing ring is provided between the sealing connector and the wall surface of the housing 10. The Hall element pins 11 are attached to and fixed to the outer wall surface of the housing 10 and pass through the wall surface of the housing 10. The Hall element pins 11 pass through the sealing connector and are welded to the PCB board 19 at the end away from the Hall element 14. Elastic metal sheets 15 are provided on both sides of the Hall element 14. The two elastic metal sheets 15 are snapped and fixed to the top end face of the sensing unit 4.

[0033] Each of the first hemispherical shell 17 and the second hemispherical shell 18 has six uniformly distributed elastic deformation zones. Each elastic deformation zone corresponds to a Hall element 14. Every two Hall elements 14 arranged opposite each other form a radial differential measurement pair.

[0034] The radially magnetized permanent magnet 8 is fixed to the top of the counterweight 9 by a support frame. The outer surface of the radially magnetized permanent magnet 8 is covered with a permalloy uniform magnetic sleeve. The counterweight 9 is made of tungsten alloy.

[0035] Example 5 This embodiment provides a water flow velocity and direction measuring device, such as... Figure 1 As shown, it includes a push rod 1 and a housing 10. The push rod 1 has a hollow structure and its lower end is integrally formed with the top of the housing 10. A vent pipe 2 and an electric wire 3 are inserted inside the push rod 1. The vent pipe 2 is connected to several air bladder surfaces 13. Several sensing units 4 are fixed to the outer surface of the housing 10. Several air bladder surfaces 13 are respectively arranged corresponding to several sensing units 4. A counterweight 9 is fixed at the bottom of the cavity of the housing 10. A radially magnetized permanent magnet 8 is provided at the center of the housing 10. The counterweight 9, the push rod 1 and the radially magnetized permanent magnet 8 are coaxially arranged.

[0036] The top of the top rod 1 has an external interface, through which a vent pipe 2 and an electrical wire 3 are threaded. The end of the vent pipe 2 away from the airbag surface 13 is connected to an electric air pump, and one end of the electrical wire 3 is connected to a power source 5. The end of the electrical wire 3 away from the power source 5 has a charging interface. The top of the top rod 1 also has a mounting structure for fixing it to an external support, survey vessel, cableway, buoy, or survey platform. The top rod 1 serves as both a mounting structure and its internal cavity as a conduit for the air pipe 2 and electrical wire 3. The external interface is located at the top of the top rod 1, avoiding the need for openings on the surface of the housing 10 to maintain its sealing integrity. The top rod 1 has a multi-section nested structure, with locking mechanisms between each section. The overall length of the top rod 1 can be adjusted by telescoping to change the depth to which the housing 10 is submerged below the water surface.

[0037] The shell 10 is a spherical shell, which is formed by joining a first hemispherical shell 17 and a second hemispherical shell 18. A sealing ring is provided on the mating surface of the first hemispherical shell 17 and the second hemispherical shell 18. Ear plates 6 are fixedly connected to the outer edges of the first hemispherical shell 17 and the second hemispherical shell 18 respectively. Bolts 7 are passed between the two ear plates 6. The first hemispherical shell 17 and the second hemispherical shell 18 are relatively fastened together by bolts 7.

[0038] The shell 10 includes an elastic deformation region and a rigid support region. The elastic deformation region and the rigid support region are integrally formed. The position of the elastic deformation region corresponds to the airbag surface 13.

[0039] like Figure 2As shown, each sensing unit 4 includes two rigid support walls 16. The bottom of the two rigid support walls 16 is fixed to the outer surface of the housing 10. Several through holes 12 are symmetrically and evenly opened on the two rigid support walls 16. Hall element pins 11 are passed through the rigid support walls 16. The two Hall element pins 11 are welded together to the Hall element 14. The wall surface of the housing 10 is provided with a wire hole. A sealing connector is provided in the wire hole. A sealing ring is provided between the sealing connector and the wall surface of the housing 10. The Hall element pins 11 are attached to and fixed to the outer wall surface of the housing 10 and pass through the wall surface of the housing 10. The Hall element pins 11 pass through the sealing connector and are welded to the PCB board 19 at the end away from the Hall element 14. Elastic metal sheets 15 are provided on both sides of the Hall element 14. The two elastic metal sheets 15 are snapped and fixed to the top end face of the sensing unit 4. Two elastic metal sheets 15 are locked together with the Hall element 14 as a single unit, referred to as an integrated component. It is only deformed by the pressure difference of the water body. The air bladder surface 13 inside the cavity of the sensing unit 4 only serves as a reset structure and does not generate pressure.

[0040] Each of the first hemispherical shell 17 and the second hemispherical shell 18 has six uniformly distributed elastic deformation zones, each corresponding to a Hall element 14. Every two Hall elements 14 arranged opposite each other form a radial differential measurement pair. The normal vectors of the 12 sensing units 4 are uniformly distributed radially along the center of the shell 10, achieving three-dimensional spatial coverage. By utilizing the topological structure of the 12 sensing units 4 centrally symmetrically distributed on the spherical surface, the dynamic pressure component collected by each measuring point under any incoming flow direction can be precisely matched and canceled by the reverse dynamic pressure component output by the measuring point located at its central symmetrical position. This ensures that the vector sum of the dynamic pressure components of all measuring points is always zero, thereby completely eliminating the influence of common-mode interference on measurement accuracy from a structural perspective.

[0041] The radially magnetized permanent magnet 8 is fixed to the top of the counterweight 9 by a support frame. The outer surface of the radially magnetized permanent magnet 8 is covered with a permalloy uniform magnetic sleeve. The counterweight 9 is made of tungsten alloy.

[0042] The inner top wall of the housing 10 has a mounting groove, in which a power supply 5 and a PCB board are fixed. The power supply 5 is electrically connected to the PCB board 19. A microcontroller is mounted on the PCB board 19, and a control program is programmed into the microcontroller. The control program includes an air pump control program, a sensor signal receiving program, a signal processing program, and a Bluetooth communication program. The microcontroller on the PCB board 19 is soldered to the Hall element pins 11. Specifically, the air pump control program controls the electric air pump, which inflates the airbag 13 through the air tube 2; the sensor signal receiving program receives the Hall voltage signal output by the Hall element 14; the signal processing program processes the Hall voltage signal output by the Hall element 14 and calculates the flow rate and direction; and the Bluetooth communication program communicates with mobile devices and outputs the measurement results.

[0043] Example 6 This embodiment provides a method for measuring water flow velocity and direction, using any one of the water flow velocity and direction measuring devices from Embodiments 1-5, and includes the following steps: Step 1: Submerge the water flow velocity measuring device in the water; Step 2: The water flow impacts the elastic deformation zone, causing local deformation in the elastic deformation zone. The Hall element 14 moves along with the elastic deformation zone and senses the change in the magnetic field of the radially magnetized permanent magnet 8, outputting a Hall voltage signal. Step 3: Subtract the Hall voltage signals from each radial differential measurement pair to obtain the differential signal; Step 4: Calculate the water flow velocity and direction based on the spatial distribution of all differential signals.

[0044] The procedure also includes the following steps: inflating the airbag surface 13 through the vent pipe 2, causing the airbag surface 13 to expand and push against the inner wall of the elastic deformation zone, restoring the elastic deformation zone to its initial spherical shape. When a reset operation is required, the PCB board sends a reset command to the air pump control program, which then controls the start of the electric air pump to inflate the airbag surface 13 through the vent pipe 2, causing the airbag surface 13 to expand. The expanded airbag surface 13 pushes against the inner wall of the elastic deformation zone at its tip, restoring the elastic deformation zone to its initial unstressed state.

[0045] Example 7 Based on the water flow velocity and direction measurement method provided in Example 6, the water flow velocity and direction measurement method provided in this example specifically includes: Step 401: Establish a calculation model for the flow pressure around the spherical measuring points of the shell 10; For a steady, incompressible, uniformly flowing water volume, neglecting small head differences at small locations, Bernoulli's energy equation is established along the same streamline:

[0046] In the formula, The static pressure at the distant point of the inflow, Pa; The constant density of water is kg / m³ 3 ; The overall inflow velocity of the water body is expressed in m / s. Let i be the hydrostatic pressure of the fluid at measuring point i, in Pa; Let i be the local water flow velocity at measuring point i, in m / s; The local flow velocity at any measuring point i on the spherical surface of shell 10 is determined by the angle θ between the incoming flow direction and the normal of the measuring point. i It was decided to introduce a dimensionless pressure coefficient. The pressure at the measuring point and the incoming flow pressure satisfy the following:

[0047] In the formula, The pressure coefficient at the measuring point is determined solely by the included angle θ. i Uniquely definite, dimensionless; When the angle θ between the normal vector of the corresponding measuring point i and the direction of the incoming flow... i In the extreme condition where the pressure coefficient is 0, i.e., when the water impacts the shell 10, the stagnation velocity at the point directly opposite the incoming flow drops to 0, and the pressure coefficient... =1, the kinetic energy is completely converted into pressure energy, and the total pressure relationship at the stagnation point is obtained:

[0048] In the formula, The total pressure at the stagnation point is Pa; Step 402: Perform linear conversion of water pressure to Hall voltage signal; When the water pressure collected at each measuring point i When the pressure is applied to the sensing unit 4 through the through-hole 12, the elastic metal sheet 15 undergoes elastic deformation. The parallel spacing between the two elastic metal sheets 15 changes linearly with the pressure difference. Within a small deformation range, the deformation satisfies Hooke's Law.

[0049] In the formula, The change in distance between the two elastic metal sheets is expressed in m. The overall elastic coefficient of the integrated component is given in m / Pa. The constant reference pressure inside the sensing unit cavity is measured in Pa. The deformation of the integrated component changes the spacing between the permanent magnet metal sheets, and the magnetic induction intensity in the Hall sensitive area changes linearly with the deformation:

[0050] In the formula, Let T be the magnetic flux density perpendicular to the sensitive surface of the Hall element. The magnetic field-deformation conversion coefficient is T / m; When a constant operating current is applied to the Hall element, the output voltage is proportional to the magnetic flux density.

[0051] In the formula, The output voltage of the Hall element at measurement point i is V; The Hall coefficient of the Hall element material is m. 3 / (A·s); The constant operating current of the Hall element is A; The thickness of the Hall chip substrate is in meters (m).

[0052]

[0053] In the formula, The total voltage-pressure sensitivity of a single-channel sensing unit is expressed in V / Pa. For zero differential pressure at measurement point i, the i-th sensing unit has zero differential pressure ( = The zero-point offset voltage, V; Step 403: Common-mode interference is eliminated, and the pure differential-mode signal is solved. The signal is split into two parts: a global common-mode component and a flow-velocity-dependent differential-mode component.

[0054] In the formula, The global electromagnetic common-mode offset voltage, V, caused by temperature and power fluctuations; For global common mode components; These are the differential mode components; among them, the global common mode component is independent of the incoming flow velocity, while the differential mode component is determined only by the flow velocity and direction. The 12 sensing units are symmetrically arranged along the center of an icosahedron. Summing all 12 differential-mode components results in natural vector cancellation.

[0055] Solving for pure differential mode signals:

[0056]

[0057]

[0058] In the formula, This includes all global disturbances such as hydrostatic pressure and electromagnetic drift. Step 404: Determine the direction of water flow; Based on the pressure distribution characteristics of the flow around a sphere, facing the incoming flow θ i When =0, =1, pure differential mode voltage Take the maximum value; reverse flow θ i When =Π, pure differential mode voltage Take the minimum value; Take the three groups adjacent to the maximum value. Combined with the corresponding spatial angle θ of the measuring point i Perform surface interpolation to obtain the three-dimensional azimuth and pitch angles of the incoming flow; Step 405: Determine the water flow velocity; Let the three-dimensional velocity vector of the incoming flow be... The unit radial normal vector at measurement point i The pressure coefficient at the measuring point meets the requirements. The one-way equation is:

[0059] The 12 sensing units correspond to 12 sets of independent equations, forming an overdetermined system of 12 equations and 3 unknowns:

[0060] The above overdetermined equations are solved using the least squares method to obtain the optimal three-dimensional velocity components. The magnitude of the combined incoming flow velocity:

[0061] Pick ,at this time The formula for calculating water flow velocity is obtained as follows:

[0062] This application presents a method for measuring water flow velocity and direction based on a water flow velocity and direction measuring device. This method enables three-dimensional omnidirectional synchronous measurement in any spatial direction, without being limited by the direction of incoming flow. It is particularly suitable for complex environments such as natural rivers, farmland irrigation canals, and municipal water supply and drainage pipelines.

Claims

1. A water flow velocity and direction measuring device, characterized in that, The device includes a top rod (1) and a housing (10). The top rod (1) is a hollow structure and its lower end is integrally formed with the top of the housing (10). A vent pipe (2) and an electric wire (3) are inserted inside the top rod (1). The vent pipe (2) is connected to several air bladder surfaces (13). Several sensing units (4) are fixed to the outer surface of the housing (10). Several air bladder surfaces (13) are respectively arranged corresponding to several of the sensing units (4). A counterweight (9) is fixed at the bottom of the cavity of the housing (10). A radially magnetized permanent magnet (8) is provided at the center of the housing (10). The counterweight (9), the top rod (1), and the radially magnetized permanent magnet (8) are coaxially arranged.

2. The water flow velocity and direction measuring device according to claim 1, characterized in that, The top of the top rod (1) is provided with an external interface, and an air pipe (2) and an electric wire (3) are installed inside the external interface. The end of the air pipe (2) away from the airbag surface (13) is connected to an electric air pump. One end of the electric wire (3) is connected to a power source (5), and the end of the electric wire (3) away from the power source (5) is provided with a charging interface.

3. The water flow velocity and direction measuring device according to claim 1, characterized in that, The shell (10) is a spherical shell, which is formed by joining a first hemispherical shell (17) and a second hemispherical shell (18). A sealing ring is provided on the mating surface of the first hemispherical shell (17) and the second hemispherical shell (18). Ear plates (6) are fixed to the outer edges of the first hemispherical shell (17) and the second hemispherical shell (18), and bolts (7) are passed between the two ear plates (6). The first hemispherical shell (17) and the second hemispherical shell (18) are relatively fastened together by bolts (7).

4. The water flow velocity and direction measuring device according to claim 3, characterized in that, The shell (10) includes an elastic deformation zone and a rigid support zone. The elastic deformation zone and the rigid support zone are integrally formed. The position of the elastic deformation zone corresponds to the airbag surface (13).

5. The water flow velocity and direction measuring device according to claim 4, characterized in that, Each of the sensing units (4) includes two rigid support walls (16). The bottom of the two rigid support walls (16) is fixed to the outer surface of the housing (10). Several through holes (12) are symmetrically and evenly opened on the two rigid support walls (16). Hall element pins (11) are passed through the rigid support walls (16). Hall element (14) is welded together on the two Hall element pins (11). A wire hole is opened on the wall of the housing (10). A sealing connector is provided in the wire hole. A sealing ring is provided between the sealing connector and the wall of the housing (10). The Hall element pin (11) is attached to the outer wall of the housing (10) and passes through the wall of the housing (10). The Hall element pin (11) passes through the sealing connector and is welded to the PCB board (19) at the end away from the Hall element (14). Elastic metal sheets (15) are provided on both sides of the Hall element (14). The two elastic metal sheets (15) are snapped and fixed to the top end face of the sensing unit (4).

6. The water flow velocity and direction measuring device according to claim 5, characterized in that, Each of the first hemispherical shell (17) and the second hemispherical shell (18) has six uniformly distributed elastic deformation zones, each of which corresponds to a Hall element (14), and every two Hall elements (14) arranged opposite each other form a radial differential measurement pair.

7. The water flow velocity and direction measuring device according to claim 1, characterized in that, The radially magnetized permanent magnet (8) is fixed to the top of the counterweight (9) by a support frame. The radially magnetized permanent magnet (8) is covered with a permalloy uniform magnetic sleeve. The counterweight (9) is made of tungsten alloy.

8. The water flow velocity and direction measuring device according to claim 1, characterized in that, The inner wall of the top of the housing (10) is provided with an installation groove, in which a power supply (5) and a PCB board are fixed. The power supply (5) is electrically connected to the PCB board (19). The PCB board (19) is provided with a microcontroller, which is programmed with a control program. The control program includes an air pump control program, a sensor signal receiving program, a signal processing program, and a Bluetooth communication program. The microcontroller on the PCB board (19) is soldered to the Hall element pin (11).

9. A method for measuring water flow velocity and direction, using the water flow velocity and direction measuring device according to any one of claims 1 to 8, characterized in that, Includes the following steps: Step 1: Submerge the water flow velocity measuring device in the water; Step 2: The water flow impacts the elastic deformation zone, causing local deformation in the elastic deformation zone. The Hall element (14) moves along with the elastic deformation zone and senses the change in the magnetic field of the radially magnetized permanent magnet (8), outputting a Hall voltage signal. Step 3: Subtract the Hall voltage signals from each radial differential measurement pair to obtain the differential signal; Step 4: Calculate the water flow velocity and direction based on the spatial distribution of all differential signals.

10. The method for measuring water flow velocity and direction according to claim 9, characterized in that, It also includes the following steps: Inflation is introduced into the airbag surface (13) through the ventilator (2), the airbag surface (13) expands and pushes against the inner wall of the elastic deformation zone, the elastic deformation zone returns to its initial spherical shape.

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