Intelligent current meter with posture compensation and water depth measurement and detection method thereof

Abstract

This invention discloses an intelligent current meter with attitude compensation and water depth measurement, and its detection method. The intelligent current meter features three main mechanisms arranged coaxially: a propeller velocity measurement mechanism, a measurement mechanism, and a tail fin balancing mechanism, ensuring underwater coaxiality and stability. The propeller velocity measurement mechanism accurately acquires flow velocity signals through a front cone flow diversion and drag reduction, streamlined blades, embedded magnets, and a sealed magnetic tube. The measurement mechanism is rigorously sealed and protected, and the tail fin mechanism uses a counterweight nut to offset attitude deviations, collaboratively ensuring stable operation. It employs a segmented algorithm to adapt to high and low flow velocities, combined with a nine-axis attitude sensor and correction algorithm to eliminate attitude deviation errors and output accurate and true flow velocity. The measurement method is based on the principle of dynamic and static pressure separation, combining true flow velocity and water temperature correction data, and accurately calculates water depth through a pressure sensor, achieving integrated monitoring of hydrological parameters. Furthermore, the modular tail fin design facilitates maintenance, the measuring rope scale is clear, and the measurement has a high degree of automation, significantly improving monitoring efficiency and accuracy.

Description

Technical Field

[0001] This invention relates to the field of water conservancy detection technology, and in particular to an intelligent current meter with attitude compensation and water depth measurement and its detection method. Background Technology

[0002] In fields such as hydrological monitoring, water conservancy projects, and environmental protection, water flow velocity and water depth are core monitoring parameters. Their measurement accuracy directly affects the scientific validity and reliability of water resource allocation, flood control and disaster reduction, and water environment management. Currently, underwater flow velocity measurement mainly relies on various current meters. Traditional current meters mostly adopt propeller-type or cup-type structures, and realize flow velocity conversion by capturing the impact of water flow on moving parts. Water depth measurement requires separate equipment such as depth sounders, making the overall monitoring process cumbersome and inefficient.

[0003] With the continuous development of water conservancy monitoring technology, the market has put forward higher requirements for the measurement accuracy, functional integration and environmental adaptability of current meters. Although existing current meters can meet the basic velocity measurement needs, there are still many technical bottlenecks in complex underwater environments (such as turbulent, rapid, and waters with high sediment content). It is difficult to achieve synchronous and accurate measurement of flow velocity and water depth, and the velocity measurement accuracy is easily affected by various factors, which cannot meet the actual needs of high-precision hydrological monitoring.

[0004] The core problems of existing technologies are mainly reflected in the following aspects: First, attitude deviation leads to low velocity measurement accuracy. Traditional current meters lack an effective attitude stabilization mechanism. When working underwater, they are easily affected by water flow impact and turbulence disturbance, resulting in attitude imbalance phenomena such as roll, pitch, and heading deviation. This causes the propeller measurement axis to be inconsistent with the water flow direction, thus producing a large velocity measurement error, especially under low flow conditions, the error is more obvious, and it cannot accurately reflect the true velocity of the water flow.

[0005] Secondly, flow velocity and water depth cannot be measured simultaneously, resulting in limited functionality. Existing equipment mostly adopts a mode of measuring flow velocity and water depth separately, requiring the operation of the current meter and depth sounder separately. This not only increases monitoring costs and operational complexity but also easily leads to measurement point deviations, resulting in mismatches between flow velocity and water depth data. This affects the integrity and correlation of monitoring data, making it difficult to achieve integrated monitoring of hydrological parameters.

[0006] Third, the structural design is unreasonable and the environmental adaptability is poor. The propeller structure of some current meters has not been optimized by fluid dynamics, resulting in large water flow impact resistance and easy generation of turbulence that interferes with the rotational stability of the propeller; the core component materials have insufficient corrosion resistance and wear resistance, and the sealing and protection design is not perfect, allowing underwater sediment and water to easily enter the interior, leading to component damage, signal loss, shortening the service life of the instrument, and making it unable to adapt to complex underwater corrosive and sediment-rich working conditions.

[0007] Fourth, the velocity measurement algorithm has limitations and insufficient adaptability. Most existing current meters use a single algorithm to calculate the velocity, which cannot take into account both high and low velocity conditions. The sensitivity is insufficient at low velocities, and the data is prone to fluctuations at high velocities. Furthermore, the lack of dynamic compensation based on attitude data further reduces the accuracy of velocity measurement. At the same time, the influence of water kinetic pressure and water temperature on water density is not considered in the water depth calculation process, resulting in a large error in water depth measurement.

[0008] Furthermore, existing current meters suffer from poor maintenance convenience. Some core components employ an integrated design, making disassembly and repair difficult. Their attitude adjustment flexibility is also insufficient, failing to fine-tune the counterweight and attitude according to different flow conditions, thus hindering their adaptability to various complex flow environments. In summary, the problems of unstable attitude, limited functionality, insufficient accuracy, and poor environmental adaptability in existing current meters have become key constraints on the development of high-precision hydrological monitoring. There is an urgent need for an intelligent current meter and measurement method capable of achieving dynamic attitude compensation and simultaneous, accurate measurement of flow velocity and water depth. Summary of the Invention

[0009] Based on the above objectives, one of the technical solutions adopted by the present invention is: an intelligent current meter with attitude compensation and water depth measurement, wherein a propeller speed measuring mechanism 1, a current meter measuring mechanism 2, and a tail fin balancing mechanism 3 are arranged along the axial direction of the current meter; The propeller speed measuring mechanism 1 is used to measure the water flow velocity of the water area to be measured. The current meter measuring mechanism 2 is used to measure the water depth of the water area to be measured and to dynamically compensate the driving direction of the current meter; The tail fin balancing mechanism 3 is used to suppress the left and right swaying and up and down pitch of the flow meter, and to keep the measurement axis of the flow meter consistent with the direction of water flow. The propeller speed measuring mechanism 1 is connected to one end of the current meter measuring mechanism 2 via a bearing; the tail fin balancing mechanism 3 is connected to the other end of the current meter measuring mechanism 2 via a tail fin fixing nut.

[0010] Furthermore, the propeller speed measuring mechanism 1 includes: The front cone mounting body 101 is mounted on the flow meter measuring mechanism 2 via a bearing; the front cone mounting body 101 has a cone-shaped structure to reduce the frontal impact resistance of the water flow. The propeller body 102 is mounted on the front cone mount 101 via bearings; At least three propeller blades 103 are located circumferentially on the cross section of the propeller body 102; A magnet measuring structure 104 is mounted on the front cone mount 101 and the propeller body 102; When the propeller blade 103 is impacted and rotated by the water flow, the magnet measuring structure 104 generates a magnetic field with periodic changes in strength to measure the water flow velocity in the water area to be measured.

[0011] Furthermore, the magnet measuring structure 104 includes: At least three powerful magnets 1051 are distributed along the central axis of the propeller body 102 and installed at one end of the propeller body 102 near the front cone mount 101, and corresponding to the propeller blades 103. Magnetor 1052 is installed inside front cone mount 101; The propeller 102 rotates under the impact of water flow, driving the powerful magnet 1051 to rotate synchronously. During the rotation, the relative positions of the powerful magnet 1051 and the magnetic tube 1052 periodically move closer and further away as the propeller blade 103 moves. When the powerful magnet 1051 rotates to a position close to the magnetic tube 1052, the magnetic field triggers the magnetic tube 1052, causing the switching state of the magnetic tube 1052 to flip. The number of flips and the pulse frequency are recorded, and the water flow velocity of the water area to be measured is obtained by using the formula of water flow velocity and pulse frequency.

[0012] Furthermore, the flow meter measuring mechanism 2 includes: Electronic housing 201, which is used to carry measurement electronic unit 202; The intermediate chamber mounting body 203 is used to withstand the impact of water flow and transmit torque, ensuring coaxiality at the front and rear, structural stability and no deformation, and bearing the stable attitude unit 204. One end of the electronic compartment mounting body 201 is connected to the front cone mounting body 101 via a bearing, and the other end of the electronic compartment mounting body 201 is connected to the intermediate compartment mounting body 203 via a sealing connection structure 205.

[0013] Furthermore, the measurement electronics unit 202 includes: Circuit board 2021, which is located inside electronic compartment mounting body 201; A nine-axis attitude sensor 2022 is located inside the electronic compartment mounting body 201; the nine-axis attitude sensor 2022 is used to collect three-dimensional spatial attitude, tilt angle, heading and motion state; A pressure sensor 2023 is mounted on the lower outer surface of the electronic housing mount 201; the pressure sensor 2023 is used to collect the water pressure of the water area to be measured; Gland connector 2024 is installed on the upper outer surface of the electronic compartment mounting body 201; the gland connector 2024 is a connector used to fix, seal and protect the cable when it passes into the electronic compartment mounting body 201. Among them, the nine-axis attitude sensor 2022, pressure sensor 2023 and magnetotube 1052 are all electrically connected to the circuit board 2021.

[0014] Furthermore, the stabilizing attitude unit 204 includes a column 2041 mounted on the outer surface of the upper and lower ends of the intermediate chamber mounting body 203, a mounting hole 2042 opened on the column 2041, and a lead weight and measuring rope mounted on the mounting hole 2042; the lead weight keeps the current meter vertical and horizontally facing the water flow, without rolling or swaying, ensuring accurate speed measurement angle; the measuring rope has scale markings for reading the water depth to achieve stratified speed measurement, and is used to withstand tension, being straightened by the weight of the lead weight to ensure vertical lowering and no position deviation.

[0015] Furthermore, the sealing connection structure 205 includes a sealing ring 2051 located near one end of the intermediate compartment mounting body 203 and a positioning groove 2052 for positioning the intermediate compartment mounting body 203 on the electronic compartment mounting body 201.

[0016] Furthermore, the tail fin balancing mechanism 3 includes a rear cone mount 301, a tail fin support frame 302, at least two horizontal wings 303 and at least two vertical wings 304; The rear cone mount 301 is mounted on the end of the intermediate compartment mount 203 that is away from the electronic compartment mount 201; The tail fin support frame 302 is inserted into the rear cone mount 301 by tail fin fixing nut 305; The horizontal wing 303 and the vertical wing 304 are mounted perpendicularly to each other on the tail wing support frame 302.

[0017] Furthermore, the vertical wing 304 is provided with an elongated hole 306 along the axial direction. A counterweight nut is installed in the elongated hole 306 to adjust the center of gravity of the tail wing and the entire instrument, so that the flow meter maintains a horizontal and upright attitude in the water and does not tilt or pitch.

[0018] A method for dynamic compensation and synchronous measurement of a current meter, applicable to the aforementioned intelligent current meter with attitude compensation and water depth measurement, comprising: S1. The propeller body 102 of the propeller speed measuring mechanism 1 drives the propeller blades 103 to rotate under the impact of water flow, which in turn drives the powerful magnet embedded in the propeller body to rotate together. When the magnet rotates with the propeller body, it will periodically approach and move away from the magnetic sensitive tube arranged in the front cone mounting body. When the powerful magnet 1051 approaches the magnetic sensitive tube 1052, the switching state of the magnetic sensitive tube 1052 flips, triggering the IO port level of the MCU on the circuit board 2021 to change. The MCU records the trigger time of each IO port level change. During the continuous rotation of the propeller body 102, the MCU counts the number of IO port level changes within a specific time, and calculates the time interval between every two adjacent level changes through a timer, and calculates the pulse frequency of the magnetic sensitive tube 1052 based on the time interval. S2. The MCU communicates with the nine-axis attitude sensor 2022 in the measurement electronics unit 202, reads the raw data of the three-axis acceleration, three-axis gyroscope and three-axis magnetometer output by the nine-axis attitude sensor 2022 in real time, and calculates the pitch angle, roll angle, heading angle and vibration data based on the raw data to realize dynamic compensation of the current meter driving direction. S3. The MCU is connected to the pressure sensor 2023 in the measurement electronics unit 202 via the IIC bus, and reads the total water pressure data and water temperature value output by the pressure sensor 2023 in real time to provide data support for water depth measurement. S4. When the pulse frequency does not exceed the set frequency, the MCU calculates the time interval between every two adjacent pulses in real time and obtains the real-time initial flow rate through the initial flow rate calculation algorithm. When the pulse frequency exceeds the set frequency, the MCU sets the measurement duration; selects a certain pulse falling edge as the start time of the timer, selects the falling edge of the Nth pulse as the node to stop the timer, counts the timing duration corresponding to the pulse, and calculates the average initial flow rate within the timing time interval using the average initial flow rate calculation algorithm; S5. Normalize the triaxial acceleration data and triaxial magnetometer data obtained in S2, and calculate the pitch angle, yaw angle and roll angle respectively. S6. Transform the instrument coordinate system of the current meter to the geographic coordinate system to obtain the rotation matrix; The initial flow velocity calculated by S4 is processed by the flow velocity calculation algorithm along the propeller axis to obtain the flow velocity along the propeller axis. The real geographic flow velocity is obtained by the real geographic flow velocity calculation algorithm and the rotation matrix. The real flow velocity after attitude compensation is obtained by the real flow velocity calculation algorithm and dynamic compensation is performed. S7. Using the principle of separating dynamic and static pressure, based on the actual flow velocity obtained in S6, the total pressure data obtained in S3 is corrected, and the corrected static pressure is obtained through the correction algorithm. Based on the corrected static pressure, the actual water depth data is calculated through the static pressure water depth formula, thus realizing the synchronous measurement of flow velocity and water depth.

[0019] Compared with existing technologies, this invention has the following advantages: 1. The propeller velocity measuring mechanism, the current meter measuring mechanism, and the tail fin balancing mechanism are arranged coaxially along the axis, and the three are closely connected to ensure coaxiality and structural stability during underwater operation, laying the foundation for accurate measurement. The propeller velocity measuring mechanism's front cone mounting body reduces drag and the streamlined propeller blades are subjected to uniform force. The embedded strong magnet and the sealed magnetic tube work together to achieve accurate acquisition of the flow velocity signal. The intermediate chamber mounting body of the measuring mechanism has stable load-bearing capacity and a tight sealed connection structure, effectively preventing the intrusion of water sediment. The streamlined rear cone and the cross-shaped wing structure of the tail fin balancing mechanism work together, with an adjustable counterweight nut, to flexibly suppress instrument sway and offset attitude deviation. The three work together to ensure the long-term stable operation of the instrument.

[0020] 2. The propeller velocity measuring mechanism balances sensitivity at both high and low flow velocities. Through a magnet-based measurement structure, it stably outputs pulse signals, providing reliable raw data for flow velocity calculation. The measurement method employs a segmented algorithm: real-time acquisition of pulse intervals at low flow velocities and statistical timing of fixed pulse intervals at high flow velocities, ensuring accurate initial flow velocity measurement under different flow velocity conditions. Simultaneously, by combining attitude data acquired from a nine-axis attitude sensor, coordinate system transformation, rotation matrix correction, and attitude compensation algorithms are used to eliminate velocity measurement errors caused by instrument tilt and pitch, ultimately outputting accurate and true flow velocity, significantly improving the reliability of velocity measurement.

[0021] 3. The measurement method adopts the principle of separating dynamic and static pressure, and combines the actual flow velocity to correct the water pressure data to eliminate dynamic pressure interference. Simultaneously, the water temperature is collected to correct the water density, and the actual water depth is accurately calculated through the static pressure water depth formula. The pressure sensor of the flow meter measurement mechanism is waterproof and sealed, and directly contacts the water body to collect data, further ensuring the accuracy of water depth measurement. It breaks through the limitation of the single function of traditional instruments, realizes integrated monitoring of hydrological parameters, and is suitable for various hydrological monitoring scenarios.

[0022] 4. The tail fin balancing mechanism adopts a modular design, and each component can be disassembled and installed, which is convenient for later inspection and maintenance; the measuring rope scale of the stabilizing attitude unit is clear, which facilitates the implementation of layered speed measurement and improves the ease of operation; the measurement method has a high degree of automation, and the circuit board serves as the control center to realize the integration of signal acquisition, processing, compensation and transmission, without much manual intervention, which greatly improves the efficiency and accuracy of hydrological monitoring. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the intelligent current meter with attitude compensation and water depth measurement according to the present invention.

[0024] Figure 2 This is a schematic diagram showing the positions of the propeller blades and the powerful magnet.

[0025] Figure 3 This is a schematic diagram of the flow meter measuring mechanism; Figure 4 This is a flowchart illustrating the method for dynamic compensation and synchronous measurement of a flow meter.

[0026] Among them, 1. Propeller speed measuring mechanism; 101. Front cone mounting body; 102. Propeller body; 103. Propeller blade; 104. Magnet measuring structure; 1041. Powerful magnet; 1042. Magneton; 2. Flow meter measuring mechanism; 201. Electronic compartment mounting body; 202. Measuring electronic unit; 2021. Circuit board; 2022. Nine-axis attitude sensor; 2023. Pressure sensor; 2024. Gland head; 203. Intermediate compartment mounting body; 204. Stabilizing attitude unit; 2041. Column; 2042. Mounting hole; 205. Sealing connection structure; 2051. Sealing ring; 2052. Positioning groove; 3. Tail fin balancing mechanism; 301. Rear cone mounting body; 302. Tail fin support frame; 303. Horizontal fin; 304. Vertical fin; 305. Tail fin fixing nut; 306. Elongated hole. Detailed Implementation

[0027] The technical solutions of the intelligent current meter with attitude compensation and water depth measurement method provided by the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0028] Example 1 like Figures 1-3 As shown, an intelligent current meter with attitude compensation and water depth measurement is provided with a propeller speed measuring mechanism 1, a current meter measuring mechanism 2 and a tail fin balancing mechanism 3 arranged along the axial direction of the current meter.

[0029] In this embodiment, the three components are coaxially arranged and closely connected to form the main structure of the current meter, ensuring the structural stability and coaxiality of the instrument when it is working underwater, and providing a structural foundation for the synchronous and accurate measurement of flow velocity, attitude, and water depth. Among them, the propeller velocity measuring mechanism 1 is located at the front end of the current meter and is arranged facing the direction of the water flow. The current meter measuring mechanism 2 is located in the middle of the overall structure and serves as a load-bearing and control unit. The tail fin balancing mechanism 3 is located at the rear end of the current meter and is used to maintain the overall attitude stability of the instrument. The three components work together to achieve integrated measurement of water flow velocity, underwater attitude, and water depth parameters.

[0030] Furthermore, the propeller velocity measuring mechanism 1 is used to measure the water flow velocity in the water area to be measured. Its structural design is adapted to complex underwater flow field environments, taking into account velocity measurement sensitivity, anti-interference ability, and structural durability. It can stably output accurate flow velocity measurement signals under different flow velocities and different turbulence conditions, providing raw data support for subsequent attitude compensation and flow velocity correction.

[0031] Specifically, the propeller speed measuring mechanism 1 includes a front cone mounting body 101, which is mounted on the current meter measuring mechanism 2 via bearings. The front cone mounting body 101 is coaxially mounted on one end of the electronic compartment mounting body 201 of the current meter measuring mechanism 2 via precision waterproof bearings, achieving a stable connection between the front cone mounting body 101 and the current meter measuring mechanism 2, while ensuring the sealing of the connection part to prevent underwater silt and water from entering the connection gap and causing component wear or short circuit.

[0032] Meanwhile, the front conical mounting body 101 has a conical structure, reducing the frontal impact resistance of the water flow. This structural design can effectively divert the oncoming water flow, significantly reducing the frontal impact resistance of the water flow on the front end of the current meter, avoiding the generation of turbulence and eddies in the water flow at the instrument front end, and reducing the impact of water flow impact on the rotational stability of the propeller body 102. This provides a good flow field environment for the smooth rotation of the propeller body 102, thereby improving the accuracy of the velocity measurement. In addition, the front conical mounting body 101 is made of corrosion-resistant, high-strength engineering plastics or metals, which can adapt to the complex underwater corrosive environment and extend the service life of the propeller velocity measuring mechanism 1.

[0033] The propeller speed measuring mechanism 1 further includes a propeller body 102, which is mounted on the front cone mounting body 101 via bearings. The propeller body 102 and the front cone mounting body 101 are strictly coaxial, ensuring that the propeller body 102 can rotate flexibly and smoothly around its own axis under the impact of water flow, avoiding phenomena such as eccentric rotation and jamming. The propeller body 102 is made of lightweight, high-strength materials, which not only ensures the rigidity of its own structure but also enables flexible rotation under the impact of low-speed water flow, improving the speed measuring sensitivity under low-speed conditions.

[0034] The propeller velocity measuring mechanism 1 further includes at least three propeller blades 103, which are located circumferentially on the cross-section of the propeller body 102. The included angle between two adjacent propeller blades 103 is equal, ensuring that the force on the propeller body 102 is uniform when rotating, avoiding rotational jitter caused by unbalanced forces, and thus improving the stability of flow velocity measurement. The propeller blades 103 adopt a streamlined curved surface design, and the blade tilt angle and windward area are optimized according to the principles of fluid mechanics. This design can generate sufficient rotational torque under low-velocity water flow impact to achieve accurate velocity measurement, and can withstand the impact force of water flow in high-velocity environments, avoiding blade deformation and damage. At the same time, it can effectively cut the water flow, reduce the impact of water flow disturbance on rotational stability, and ensure that the rotational speed of the propeller body 102 maintains a good linear correspondence with the water flow speed.

[0035] The propeller velocity measuring mechanism 1 further includes a magnet measuring structure 104, which is mounted on the front cone mount 101 and the propeller body 102. When the propeller blades 103 are impacted and rotated by the water flow, the magnet measuring structure 104 generates a periodic change in the strength of the magnetic field to measure the water flow velocity in the area under test. When the water flow impacts the propeller blades 103, the propeller blades 103, under the thrust of the water flow, drive the propeller body 102 to rotate uniformly around its axis. Simultaneously, the propeller body 102 drives the magnet component at its end to rotate in a circular motion, causing a periodic change in the relative position between the magnet and the magnetic sensing element in the magnet measuring structure 104. This results in a periodic alternation of magnetic field strength. After the magnetic sensing element captures this magnetic field change signal, it converts it into an electrical signal output. By recording the frequency of the magnetic field change, i.e., the pulse frequency, and combining it with a preset flow velocity calculation model, the water flow velocity in the area under test can be accurately calculated.

[0036] Furthermore, the magnet measuring structure 104 includes at least three powerful magnets 1051, which are distributed and installed along the central axis of the propeller body 102 at one end of the propeller body 102 near the front cone mount 101 and correspond to the propeller blades 103.

[0037] Specifically, the powerful magnet 1051 is a high-performance neodymium iron boron magnet, characterized by high magnetic field strength, strong stability, and corrosion resistance, making it suitable for long-term underwater operation. Furthermore, the installation position of each powerful magnet 1051 corresponds one-to-one with the propeller blade 103, ensuring that when the propeller body 102 rotates, the powerful magnet 1051 can synchronously rotate with the propeller blade 103, and the angle between two adjacent powerful magnets 1051 is consistent with the angle between two adjacent propeller blades 103, guaranteeing the regularity and stability of the magnetic field changes. The powerful magnet 1051 is embedded and inlaid, its surface flush with the end face of the propeller body 102, not protruding from the end face, avoiding turbulence caused by water flow impact, and preventing weeds, debris, or impacts from damaging the magnet, ensuring stable output of the magnetic field signal.

[0038] The magnet measurement structure 104 further includes a magnetosensitive tube 1052, which is installed inside the front conical mounting body 101. Specifically, the magnetosensitive tube 1052 is selected from reed switches or Hall sensors, which have the advantages of high sensitivity, fast response speed, and low power consumption. It can accurately capture minute changes in magnetic field strength and is suitable for underwater low-power, high-precision measurement requirements. The magnetosensitive tube 1052 is fixedly installed inside the front conical mounting body 101 and is coaxial with the front conical mounting body 101 and the propeller body 102. Its installation position is radially aligned with the annular distribution trajectory of the powerful magnet 1051, ensuring that the powerful magnet 1051 can achieve precise alignment with the magnetosensitive tube 1052 when rotating. At the same time, a preset small gap of 0.5-2mm is maintained between the magnetosensitive tube 1052 and the powerful magnet 1051. This gap can ensure that the powerful magnet 1051 does not collide with the magnetosensitive tube 1052 when rotating, and can also ensure that the magnetosensitive tube 1052 can effectively capture the magnetic field signal, avoiding signal loss or false triggering due to magnetic field attenuation. In addition, the front cone mounting body 101 provides a sealed protection for the magnetic tube 1052, preventing underwater water and sediment from contacting the magnetic tube 1052, thus preventing short circuits and damage to the magnetic tube 1052 and extending its service life.

[0039] The propeller 102 rotates under the impact of water flow, driving the powerful magnet 1051 to rotate synchronously. During the rotation, the relative positions of the powerful magnet 1051 and the magnetic tube 1052 periodically move closer and further away as the propeller blade 103 moves. When the powerful magnet 1051 rotates to a position close to the magnetic tube 1052, the magnetic field triggers the magnetic tube 1052, causing the switching state of the magnetic tube 1052 to flip. The number of flips and the pulse frequency are recorded, and the water flow velocity of the water area to be measured is obtained by using the formula of water flow velocity and pulse frequency.

[0040] Specifically, when the powerful magnet 1051 rotates to a position close to the magnetic tube 1052, the magnetic tube 1052 is triggered by the magnetic field of the powerful magnet 1051, and its internal switching state flips, changing from open to closed or from closed to open. When the powerful magnet 1051 rotates to a position away from the magnetic tube 1052, the magnetic field strength weakens, and the switching state of the magnetic tube 1052 returns to its initial state. The circuit board 2021 in the flow meter measuring mechanism 2 records the number of flips and the flip frequency (i.e., pulse frequency) of the switching state of the magnetic tube 1052 in real time. Combined with the preset formula for calculating water flow velocity and pulse frequency, the pulse signal is converted into the corresponding water flow velocity value, and finally the accurate water flow velocity of the water area to be measured is obtained, realizing real-time and continuous measurement of water flow velocity.

[0041] In this embodiment, the propeller velocity measuring mechanism, the current meter measuring mechanism, and the tail fin balancing mechanism are coaxially and tightly connected. The conical design of the front conical mounting body can divert water flow, reduce impact, and avoid turbulence interfering with propeller rotation, laying the foundation for accurate velocity measurement. The propeller body and the front conical mounting body are strictly coaxial, and with evenly distributed streamlined propeller blades, the force is balanced and the rotation is stable, ensuring that the propeller speed corresponds linearly to the water flow velocity, taking into account the velocity measurement sensitivity under both high and low flow velocity conditions.

[0042] High-performance neodymium iron boron magnets are matched one-to-one with the propeller blades, and the embedded installation avoids water flow interference and component damage; the magnetosensitive tube is precisely aligned and sealed for protection, and can quickly capture the periodic changes in the magnetic field and convert them into electrical signals. Combined with the pulse frequency calculation of the circuit board, it can realize real-time and accurate measurement of water flow velocity, providing reliable raw data for subsequent processing.

[0043] The current meter measuring mechanism 2 also includes an intermediate chamber mounting body 203. This intermediate chamber mounting body 203 is also made of high-strength, corrosion-resistant material and has a rigid structure. Its core function is to withstand the impact of underwater water flow and transmit torque. It connects the electronic chamber mounting body 201 and the tail fin balancing mechanism 3, ensuring that the front and rear structures of the current meter are coaxial, stable, and undeformed, preventing structural loosening or displacement due to water flow impact. It provides a stable mounting foundation for the propeller speed measuring mechanism 1 and the tail fin balancing mechanism 3. Simultaneously, the intermediate chamber mounting body 203 also supports the attitude stabilization unit 204, providing a robust mounting carrier for the attitude stabilization unit 204 and ensuring that the attitude stabilization unit 204 can effectively perform its attitude stabilization function. One end of the electronic compartment mounting body 201 is connected to the front cone mounting body 101 through a precision waterproof bearing, which not only achieves a stable connection between the two, but also ensures the flexible rotation of the propeller speed measuring mechanism 1, while enhancing the sealing of the connection part; the other end of the electronic compartment mounting body 201 is connected to the intermediate compartment mounting body 203 through a sealing connection structure 205, achieving a seamless connection between the two, further improving the overall sealing and structural stability of the flow meter measuring mechanism 2.

[0044] Furthermore, the measurement electronic unit 202, as the core functional unit of the current meter measurement mechanism 2, is responsible for signal acquisition, processing, transmission and control. It includes a circuit board 2021, which is fixedly installed inside the electronic compartment mounting body 201. It adopts a waterproof and corrosion-resistant design and integrates core components such as MCU, signal processing module, and data transmission module. It is the "control center" of the entire current meter, used to receive and process signals transmitted by various sensors, and to complete core functions such as flow velocity calculation, attitude compensation, and water depth calculation. At the same time, it realizes real-time data transmission and storage.

[0045] The measurement electronics unit 202 also includes a nine-axis attitude sensor 2022. The nine-axis attitude sensor 2022 is fixedly installed inside the electronics housing 201 and is tightly fitted and coaxially arranged with the circuit board 2021 to ensure accurate and reliable attitude data acquisition. This nine-axis attitude sensor 2022 integrates a three-axis accelerometer, a three-axis gyroscope, and a three-axis magnetometer, enabling real-time acquisition of the current meter's three-dimensional spatial attitude, tilt angle, heading, and motion state data underwater, including key parameters such as roll angle, pitch angle, heading angle, and vibration frequency. This provides accurate data support for dynamic attitude compensation of the current meter. By detecting instrument attitude deviations in real time, it feeds back to the circuit board 2021 for compensation calculations, correcting flow velocity measurement errors.

[0046] The measurement electronic unit 202 also includes a pressure sensor 2023. The pressure sensor 2023 is waterproof and sealed, installed on the lower outer surface of the electronic housing mounting body 201. Its detection end faces the water body, allowing direct contact with the water in the area to be measured. It accurately collects water pressure data and simultaneously collects water temperature values ​​to correct for water pressure measurement errors. Water temperature affects water density, thus affecting the accuracy of pressure-to-depth conversion. The pressure sensor 2023 features high precision and high response speed, adapting to measurement environments with different water depths and temperatures, providing core raw data for water depth calculation.

[0047] The measurement electronics unit 202 also includes a gland 2024, which is waterproof and sealed and installed on the outer surface of the upper end of the electronic housing mounting body 201. It serves as a dedicated connector for cables entering the electronic housing mounting body 201, and its core function is to secure, seal, and protect the cables. The gland 2024 firmly clamps the cable, preventing loosening or breakage caused by water pulling or shaking. Its sealing structure effectively isolates underwater water and sediment from entering the electronic housing mounting body 201, protecting the internal circuit board 2021 and other electronic components from damage. Furthermore, the gland 2024 also provides electromagnetic interference protection, ensuring the stability of the cable signal transmission. The nine-axis attitude sensor 2022, pressure sensor 2023, and magnetotransistor 1052 are all electrically connected to the circuit board 2021 via waterproof wiring, ensuring that the signals from each sensor are accurately and stably transmitted to the circuit board 2021 for processing, enabling the coordinated operation of all components.

[0048] Furthermore, the stabilizing attitude unit 204, serving as an auxiliary component for stabilizing the attitude of the current meter, is installed on the intermediate chamber mounting body 203. It includes a column 2041 mounted on the outer surfaces of the upper and lower ends of the intermediate chamber mounting body 203, mounting holes 2042 formed in the column 2041, and a lead weight and measuring rope mounted in the mounting holes 2042. The column 2041 is made of a rigid material and is integrally formed with or firmly connected to the intermediate chamber mounting body 203 to ensure load-bearing strength. The mounting holes 2042 are precisely located at the center of the column 2041 for the secure installation of the lead weight and measuring rope, preventing the lead weight from falling off or the measuring rope from loosening during measurement. The lead weight, made of high-density metal, is quite heavy. Its core function is to provide counterweight for the current meter, allowing it to descend vertically to the water layer being measured. It also holds the entire current meter in place, maintaining a vertical and horizontal orientation underwater, preventing it from tumbling or swaying. This ensures the measuring axis of the propeller velocity measuring mechanism 1 is aligned with the water flow direction, guaranteeing accurate velocity measurement angles and avoiding errors caused by tilting. The measuring rope is made of high-strength, wear-resistant, and corrosion-resistant material, with clear graduations on its surface. This allows for direct reading of the current meter's immersion depth, facilitating stratified velocity measurement at different water layers. Simultaneously, the rope can withstand the weight of the lead weight and the tension of the water flow, remaining taut under its own weight to ensure the current meter is lowered vertically, preventing point displacement during descent and ensuring the accuracy of the measurement point.

[0049] Furthermore, the sealing connection structure 205 is used to achieve a sealed connection between the electronic compartment mounting body 201 and the intermediate compartment mounting body 203, ensuring the overall sealing of the flow meter measuring mechanism 2 and preventing underwater water and sediment from entering and damaging the electronic components. It includes a sealing ring 2051 located near the end of the intermediate compartment mounting body 203 and a positioning groove 2052 for positioning the intermediate compartment mounting body 203 on the electronic compartment mounting body 201. The sealing ring 2051 is made of high-temperature resistant, corrosion-resistant, and highly elastic fluororubber or silicone rubber. It is embedded between the mating surfaces of the electronic compartment mounting body 201 and the intermediate compartment mounting body 203. When the two are mated and tightened, the sealing ring 2051 is fully compressed to form a tight sealing surface, effectively preventing the intrusion of water and sediment. The positioning groove 2052 is opened on the end face of the electronic compartment mounting body 203 near the intermediate compartment mounting body 203. Its size is adapted to the mating end of the intermediate compartment mounting body 203, which can realize the precise positioning and installation of the intermediate compartment mounting body 203, ensure that the two are coaxially mated, avoid structural loosening and sealing failure caused by installation misalignment, and facilitate installation and disassembly, improving the convenience of later maintenance.

[0050] In this embodiment, the intermediate chamber mounting body is made of high-strength, corrosion-resistant, and rigid material, which can effectively withstand the impact of water flow, transmit torque, and stably connect the electronic chamber and the tail fin mechanism. This ensures that the instrument is coaxial and not easily deformed, providing a reliable mounting foundation for the propeller speed measuring mechanism and the tail fin mechanism. At the same time, it supports the stable attitude unit and helps the instrument maintain a good attitude.

[0051] The sealed connection structure, through the cooperation of the sealing ring and the positioning groove, achieves seamless docking between the electronic compartment and the intermediate compartment, effectively preventing the intrusion of water and sediment; the waterproof design of the gland and other components further strengthens the sealing protection, prevents short circuits and component damage, and extends the service life of the instrument.

[0052] Each measurement electronic unit performs its own function. The circuit board, as the control center, efficiently processes signals from various sensors and completes core calculations such as flow velocity, attitude, and water depth. The nine-axis attitude sensor accurately collects attitude data, providing support for dynamic compensation and correcting velocity measurement errors. The pressure sensor accurately collects pressure and temperature data, ensuring the accuracy of water depth calculations.

[0053] The stabilizing attitude unit uses lead weights and measuring ropes for positioning, allowing the instrument to sink vertically and face the water flow directly, avoiding tumbling and swinging, and ensuring accurate speed measurement angles. The measuring rope scale facilitates layered speed measurement, ensuring precise measurement points and further improving overall measurement performance.

[0054] Furthermore, the tail fin balancing mechanism 3, as the core component for stabilizing the rear attitude of the current meter, plays a crucial role in suppressing the lateral swaying and vertical pitching of the current meter during underwater operation. This effectively counteracts attitude deviations caused by water flow impact and turbulent disturbances, maintaining the current meter's measurement axis consistently aligned with the water flow direction. This provides a stable attitude foundation for the accurate velocity measurement of the propeller velocity measuring mechanism 1 and the water depth measurement of the pressure sensor 2023, avoiding measurement errors caused by instrument attitude misalignment and ensuring the reliability of velocity and depth measurement data. Specifically, the propeller velocity measuring mechanism 1 is connected and installed on one end of the current meter measuring mechanism 2 via a precision waterproof bearing, enabling flexible rotation and stable positioning of the propeller velocity measuring mechanism 1. The tail fin balancing mechanism 3 is securely installed on the other end of the current meter measuring mechanism 2, i.e., the end of the intermediate compartment mounting body 203 away from the electronic compartment mounting body 201, via a tail fin fixing nut 305. This ensures that the tail fin balancing mechanism 3, the current meter measuring mechanism 2, and the propeller velocity measuring mechanism 1 are coaxially arranged, guaranteeing the coaxiality and stability of the overall instrument structure and preventing attitude imbalance caused by installation misalignment.

[0055] Furthermore, the tail fin balancing mechanism 3 adopts a modular structure design, facilitating installation, disassembly, and subsequent maintenance. Specifically, it includes a rear cone mount 301, a tail fin support frame 302, at least two horizontal wings 303, and at least two vertical wings 304. These components work together to achieve stable control of the instrument's attitude. The rear cone mount 301 is made of corrosion-resistant, high-strength rigid material and has a streamlined conical structure with its tip pointing towards the water flow. This forms a symmetrical streamlined structure with the front cone mount 101, effectively diverting the water flow at the rear end, reducing the impact resistance of the water flow on the tail fin balancing mechanism 3, and preventing turbulence and eddies at the tail end, further optimizing the instrument's hydrodynamic performance. The rear cone mount 301 is securely installed on the end of the intermediate compartment mount 203 away from the electronic compartment mount 201. The mounting surface is sealed to prevent underwater water and sediment from entering the connection gap, while ensuring the installation's stability and the ability to withstand the torque caused by the water flow impact.

[0056] The tail fin support frame 302 is made of rigid metal or engineering plastic and has an overall columnar structure. One end of it is detachably inserted into the central mounting hole of the rear cone mount 301 via a tail fin fixing nut 305. After installation, it remains coaxial with the rear cone mount 301 and the intermediate compartment mount 203. The locking action of the tail fin fixing nut 305 effectively prevents the tail fin support frame 302 from loosening or rotating under the impact of water flow, ensuring the structural stability of the tail fin balance mechanism 3. The other end of the tail fin support frame 302 is used to install the horizontal fin 303 and the vertical fin 304. Its surface is provided with a precise installation positioning structure to ensure that the installation angle of the horizontal fin 303 and the vertical fin 304 is accurate and the position is firm.

[0057] Both the horizontal wing 303 and the vertical wing 304 adopt a streamlined thin-plate structure, made of high-strength, lightweight, and corrosion-resistant materials. This effectively provides the damping force required for attitude stability while minimizing water flow resistance, avoiding additional interference with the overall instrument attitude. The horizontal wing 303 and vertical wing 304 are mounted perpendicularly to each other on the tail wing support frame 302, forming a cross-shaped tail wing structure. The horizontal wing 303, arranged horizontally, primarily suppresses the pitch motion of the current meter, preventing the instrument from bouncing or tilting under the impact of water flow. The vertical wing 304, arranged vertically, primarily suppresses the lateral sway and directional deviation of the current meter, ensuring the instrument always remains aligned with the water flow direction. Their combined action achieves all-around attitude stability. Furthermore, there are at least two horizontal wing 303s and two vertical wing 304s, symmetrically distributed on both sides of the tail wing support frame 302, ensuring uniform force distribution and further enhancing attitude stability.

[0058] Furthermore, the vertical wing 304 is provided with an elongated hole 306 extending along the axial direction of the current meter. A counterweight nut is slidably installed in the elongated hole 306. The counterweight nut is adapted to the elongated hole 306 and can slide freely along the axial direction of the elongated hole 306, and is fixed in any preset position by a locking structure. Its core function is to adjust the installation position of the counterweight nut in the elongated hole 306 to adjust the overall center of gravity distribution of the tail wing balance mechanism 3 and the entire instrument, so that the current meter can maintain a horizontal and upright attitude underwater, effectively avoiding the instrument from tilting or pitching. Specifically, when the instrument tilts or pitches slightly underwater, the position of the counterweight nut can be moved to change the center of gravity at the tail wing end, offsetting the attitude deviation and restoring the instrument to the optimal measurement attitude of horizontally facing the water flow. At the same time, adapting to different water flow conditions and water depth environments, by fine-tuning the position of the counterweight, the instrument can maintain attitude stability in various complex flow fields, further improving measurement accuracy and reliability.

[0059] In this embodiment, the tail fin balancing mechanism effectively suppresses the instrument's underwater lateral sway and vertical pitch, counteracting attitude deviations caused by water flow impact and turbulent disturbances. It maintains the measurement axis aligned with the water flow direction, providing a stable attitude foundation for propeller velocity and water depth measurements, avoiding measurement errors caused by attitude skew, and improving data reliability. Simultaneously, the adjustable counterweight nut within the vertical fin's elongated hole allows for flexible adjustment of the overall center of gravity, counteracting slight attitude deviations and adapting to complex flow field conditions.

[0060] The tail fin balancing mechanism, the current meter measuring mechanism, and the propeller speed measuring mechanism are arranged coaxially. The rear cone mounting body adopts a streamlined cone structure, forming a symmetrical streamlined design with the front cone. This can divert the water flow at the rear end, reduce impact resistance, and optimize hydrodynamic performance. All components are made of high-strength and corrosion-resistant materials, are firmly installed, and can withstand the impact torque of the water flow, preventing structural loosening and deformation.

[0061] The horizontal and vertical blades adopt a streamlined thin-plate design, which takes into account both attitude stability damping force and water flow resistance control. The symmetrical distribution ensures uniform force distribution. All components are made of corrosion-resistant materials and the mounting surfaces are sealed to effectively prevent water and sediment intrusion, extend the service life of components, and adapt to various complex underwater environments.

[0062] Example 2 like Figure 4 As shown, a method for dynamic compensation and synchronous measurement of a current meter is described. This method is applicable to the intelligent current meter with attitude compensation and water depth measurement described in Example 1 above. The method includes: S1. Pulse Signal Acquisition and Frequency Calculation: Under the impact of the water flow in the water area to be measured, the propeller body 102 of the propeller speed measuring mechanism 1 drives its circumferentially uniformly distributed propeller blades 103 to rotate at a constant speed around its own axis, thereby synchronously driving the powerful magnet 1051 embedded in the propeller body 102 near the front cone mounting body 101 to rotate in a circle. Since the powerful magnet 1051 corresponds one-to-one with the propeller blades 103 and is uniformly distributed in a ring, as the propeller body 102 continues to rotate, it drives the powerful magnet embedded in the propeller body to rotate together. When the magnet rotates with the propeller body, it will periodically approach and move away from the magnetic sensitive tube arranged in the front cone mounting body, causing the magnetic field strength of the magnetic sensitive tube 1052 to change periodically. When the powerful magnet 1051 rotates to a preset sensing range close to the magnetosensitive tube 1052, the magnetic field triggers the magnetosensitive tube 1052, causing its internal switch state to flip from open to closed or from closed to open. This flipping action triggers a level change in the IO port of the MCU on the circuit board 2021. The MCU records the exact trigger time of each IO port level change in real time. During the continuous rotation of the propeller body 102, the MCU counts the total number of IO port level changes within a specific time, i.e., the pulse count, and calculates the time interval between two adjacent level changes, i.e., the pulse interval, through its integrated timer. Based on the correspondence between the pulse interval and the frequency, the MCU calculates the pulse frequency of the magnetosensitive tube 1052, providing core signal parameters for subsequent initial flow velocity calculation.

[0063] S2. Attitude Data Acquisition and Dynamic Compensation: The MCU establishes real-time communication with the nine-axis attitude sensor 2022 in the measurement electronics unit 202 via a preset communication bus, which can be selected from IIC bus, SPI bus, or UART bus. It reads the raw data output by the nine-axis attitude sensor 2022 in real time, including three-axis acceleration data. , , Three-axis gyroscope data and three-axis magnetometer data , , After the MCU performs filtering and noise reduction preprocessing on the raw data it reads, it calculates the current pitch angle of the current meter based on the attitude calculation algorithm. Roll angle Heading angle The system collects vibration data to monitor the current meter's attitude underwater in real time. Simultaneously, based on the calculated attitude data, it determines whether the current meter exhibits attitude deviations such as tilt, pitch, or heading. Through a pre-set compensation algorithm, it dynamically adjusts the current meter's drive direction to counteract attitude deviations caused by water flow impact and turbulent disturbances. This ensures the current meter maintains the optimal horizontal measurement attitude facing the water flow, guaranteeing the accuracy of subsequent flow velocity and depth measurements.

[0064] S3. Pressure Data Acquisition: Acquire real-time pressure data to provide basic data support for water depth measurement; the MCU establishes a stable connection with the pressure sensor 2023 in the measurement electronics unit 202 via the IIC bus, and reads two core data points output by the pressure sensor 2023 in real time: Total Water Pressure Data. Total water temperature value Among them, the total water pressure data directly reflects the pressure conditions at the underwater measurement points and is the core raw data for water depth calculation; the water temperature value is used to correct for water density. Because the density of water fluctuates slightly with temperature, affecting the accuracy of pressure-to-depth conversion, synchronously collecting water temperature data can improve the accuracy of subsequent depth calculations. The 2023 pressure sensor features a waterproof, sealed design, directly contacting the water body to ensure the accuracy and reliability of the collected data, making it suitable for underwater measurement environments with varying depths and temperatures.

[0065] S4. Initial Flow Velocity Calculation: Based on the pulse frequency calculated in S1, the initial flow velocity is calculated using a piecewise algorithm to adapt to different flow velocity conditions, ensuring accurate velocity measurement under both low and high flow velocities. When the pulse frequency does not exceed the set frequency (determined based on the flow rate meter's range and the rotational speed characteristics of the propeller 102, with a range of 10Hz-100Hz), it is considered a low flow rate condition. In this case, the MCU calculates the time interval between every two adjacent pulses in real time. The real-time initial flow velocity is obtained through an initial flow velocity calculation algorithm. The specific calculation formula is as follows: , in, This is the real-time initial flow velocity value, in m / s; The time interval between two adjacent pulses, in seconds; The number of powerful magnets 1051 embedded on the propeller body 102 is the same as the number of propeller blades 103; This is the flow velocity value corresponding to a propeller body 102 rotating at 1 revolution / second, in m / s. It is a preset calibration parameter, determined according to the factory calibration of the flow meter. This is the starting flow rate value of the flow meter, in m / s, which is the minimum water flow velocity required for the propeller body 102 to start rotating. It is a preset fixed parameter.

[0066] When the pulse frequency exceeds the set frequency, it is considered a high-flow-rate operating condition. In this case, the MCU first sets the preset measurement duration. The settings are based on the actual measurement accuracy requirements; then, the falling edge of a certain pulse is selected as the start time of the timer, and the interval is selected. pulse The preset positive integer is determined based on the measurement duration. The falling edge, after being set appropriately, is used as the timer's termination time. The timer is then used to calculate the... The timing time corresponding to each pulse And must meet , To ensure the timing covers the preset measurement duration and improve the representativeness of the average flow velocity, the average initial flow velocity is finally calculated using an algorithm. Average initial flow velocity over the time period The specific calculation formula is as follows: , in, for The average initial flow velocity over the time period, in m / s; The number of pulses selected is a positive integer; For the first The timing time corresponding to the first pulse is from the falling edge of the starting pulse to the second pulse. The total time of the falling edge of each pulse, in seconds; The number of powerful magnets 1051 embedded on the propeller body 102 is the same as the number of propeller blades 103; This is the flow velocity value corresponding to a propeller body 102 rotating at 1 revolution / second, in m / s. It is a preset calibration parameter, determined according to the factory calibration of the flow meter. This is the starting flow rate value of the flow meter, in m / s, which is the minimum water flow velocity required for the propeller body 102 to start rotating. It is a preset fixed parameter.

[0067] S5. Precise calculation of attitude angles: Calculate the triaxial acceleration data obtained in S2. , , and triaxial magnetometer data , , Normalization is performed to eliminate calculation errors caused by differences in data magnitude, ensuring the accuracy of attitude angle calculations. After normalization, the pitch angle of the current meter is calculated. Heading angle and roll angle This provides accurate attitude parameters for subsequent coordinate system transformation and attitude compensation.

[0068] The first step is to normalize the triaxial acceleration data. The specific formula is as follows: , in, , , The raw triaxial acceleration data collected by the 2022 nine-axis attitude sensor is in m / s². , , The normalized triaxial acceleration data has a value range of [-1, 1], eliminating the influence of data magnitude.

[0069] The second step is to normalize the triaxial magnetometer data, using the following formula: , in, , , Raw triaxial magnetometer data acquired by the 2022 nine-axis attitude sensor, in units of ; , , The data is normalized triaxial magnetometer data, with values ​​ranging from [-1, 1], eliminating the influence of data magnitude.

[0070] The third step involves calculating the pitch angle based on the normalized acceleration and magnetometer data. Heading angle and roll angle The specific calculation formula is as follows: , , , in, The pitch angle reflects the degree of tilt of the flow meter; a positive value indicates that the front end is tilted upwards, and a negative value indicates that the front end is tilted downwards. The roll angle reflects the degree of tilt of the flow meter to the left and right; a positive value indicates an upward tilt to the left and a negative value indicates an upward tilt to the right. This is the heading angle, reflecting the heading direction of the current meter, with true north as the reference and clockwise as the positive direction; , , These are the normalized triaxial acceleration data; , , The data is the normalized triaxial magnetometer data; , For inverse trigonometric functions, where Used to determine the quadrant of the angle, improving the accuracy of heading angle calculation.

[0071] S6. Attitude Compensation and Calculation of Actual Flow Velocity: Since the current meter may have attitude deviation underwater, the initial flow velocity measured by the propeller speed measuring mechanism 1 will deviate from the actual water flow velocity. Therefore, it is necessary to obtain the accurate actual flow velocity through coordinate system transformation and attitude compensation, and to achieve dynamic compensation.

[0072] First, establish the instrument coordinate system of the flow meter. The coordinate system established based on the current meter's own axis is transformed into the geographic coordinate system. The system is based on the earth. The axis points due east. The axis points due north. A coordinate system is established with the axis pointing vertically downwards; the transformation process uses a rotation matrix. Implementation, rotation matrix The specific formula is as follows: , in, For the instrument coordinate system Connect to geographic coordinate system The rotation matrix of the coordinate system is a 3×3 matrix, used to realize vector transformation between two coordinate systems; The pitch angle calculated in S5 is in rad. The roll angle calculated in S5 is in rad. This is the heading angle calculated in S5, in rad. Subsequently, the initial flow velocity obtained from S4 was calculated using the flow velocity calculation algorithm along the propeller shaft. or The process is performed to obtain the flow velocity along the propeller shaft. Since the rotation direction of the propeller body 102 is the same as that of the propeller shaft, the flow velocity along the propeller shaft can be expressed in vector form: ,in, This is the velocity vector along the propeller axis, in m / s. The initial flow velocity calculated in S4 or The unit is m / s; the last two elements of the vector are 0, indicating that the instrument coordinate system is along the propeller axis. The axis is the only direction of flow velocity; there are no flow velocity components in other directions.

[0073] Next, using a real geographic flow velocity calculation algorithm and a rotation matrix... The flow velocity along the propeller shaft Convert to real geographic flow rate The specific formula is as follows: , in, This is the true geographic velocity vector, in m / s, reflecting the actual flow velocity and direction of water in the geographic coordinate system; Rotation matrix The inverse matrix is ​​used to convert the velocity vector in the instrument coordinate system to the velocity vector in the geographic coordinate system. The inverse matrix is ​​calculated by the adjoint matrix method or Gaussian elimination method. This is the velocity vector along the propeller shaft, in m / s.

[0074] When the current meter is operating underwater, the roll angle is affected by the tail fin balancing mechanism 3 and the attitude stabilizing unit 204. The value is extremely small and can be ignored, that is... ,Will Substituting into the above formula, and expanding it, the true flow velocity after attitude compensation is obtained through the true flow velocity calculation algorithm. The specific expansion formula is as follows: , in, The actual flow velocity after attitude compensation is expressed in m / s, and the final accurate flow velocity value is given. The initial flow velocity calculated in S4 or Unit: m / s; The pitch angle is expressed in rad. Ignore the effect of roll; This is the heading angle, measured in rad.

[0075] Finally, the MCU will calculate the actual flow rate. The data is fed back to the attitude compensation module, which, combined with the attitude data collected in S2, dynamically compensates for the driving direction of the flow meter, ensuring that the flow meter maintains the best attitude and continuously outputs accurate flow velocity data during subsequent measurements.

[0076] S7. Synchronous Measurement and Correction of Water Depth: Employing the principle of separating dynamic and static pressures, combined with the actual flow velocity obtained from S6. Total pressure data obtained from S3 Corrections are made to eliminate the influence of water flow pressure on static pressure measurement, resulting in the corrected static pressure. Then, based on the corrected static pressure, the actual water depth data is calculated using the static pressure water depth formula, ultimately achieving synchronous measurement of flow velocity and water depth.

[0077] First, the total pressure data is corrected using a correction algorithm to obtain the corrected static pressure. The specific correction formula is as follows: , in, This is the corrected static pressure, expressed in Pa, which is the pressure generated solely by water depth and does not include the dynamic pressure of the water. The total pressure of the water body measured in S3 is in Pa, which includes static pressure and dynamic pressure. This is a turbulence correction factor, with a value ranging from 1.05 to 1.2. It is determined based on the on-site water flow conditions, such as turbulence intensity, and is used to correct the influence of turbulence on pressure measurement. This represents the density of water, expressed in kg / m³, with a default value of 1000 kg / m³. The value can be adjusted based on the water temperature collected by S3. Make corrections; The actual flow velocity after attitude compensation obtained in S6 is expressed in m / s. The drag coefficient, with a value ranging from 0.2 to 0.5, is determined based on the shape and structure of the flow meter and its fluid dynamic characteristics. The added pressure, measured in Pa, is caused by the eddies generated when water flows through the current meter. Noise reduction and correction are performed using a moving average filtering method with a filter window size of 3-10 data points, under natural river conditions. It is usually taken as 0.

[0078] Subsequently, based on the corrected static pressure The actual water depth h is calculated using the hydrostatic water depth formula, as follows: , in, The actual water depth is expressed in meters (m), representing the actual water depth at the measurement point. This is the corrected static pressure, in Pa. Here is the density of water, expressed in kg / m³, as shown in the corrected formula above. The meaning and value are consistent; This is the acceleration due to gravity, measured in m / s², with a default value of 9.8 m / s², which can be fine-tuned according to the latitude of the measurement area.

[0079] Through the above steps, dynamic attitude compensation of the current meter under water was achieved, and synchronous and accurate measurement of current velocity and water depth was completed. This solved the technical problems of existing current meters being easily affected by attitude deviation and unable to measure current velocity and water depth synchronously, thus improving the accuracy and reliability of hydrological parameter monitoring.

[0080] In this embodiment, a segmented algorithm is used to calculate the initial flow velocity. Pulse intervals are collected in real time at low flow velocities, and the timing of fixed pulse intervals is statistically analyzed at high flow velocities. Combined with precise pulse frequency acquisition, reliable initial flow velocity data can be output under both high and low flow velocity conditions. With dynamic attitude compensation, data is collected by a nine-axis attitude sensor, attitude angles are calculated, and coordinate system transformation and rotation matrix correction are combined to eliminate the velocity measurement error caused by attitude deviation and obtain accurate and true flow velocity.

[0081] By adopting the principle of separating dynamic and static pressure, and combining the total pressure data with the actual flow velocity to eliminate dynamic pressure interference, the actual water depth is calculated using the static pressure water depth formula. Simultaneously, water temperature is collected to correct water density, further improving the accuracy of water depth calculation. This breaks through the limitation of traditional instruments having only one function and realizes integrated monitoring of hydrological parameters.

[0082] By collecting attitude data in real time and providing feedback on actual flow velocity, the instrument's driving direction is dynamically adjusted. Combined with the attitude stabilization effect of the tail fin balancing mechanism, the instrument is ensured to always be in the optimal measurement attitude, continuously outputting accurate data and significantly improving the accuracy and reliability of hydrological monitoring.

[0083] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. An intelligent current meter with attitude compensation and water depth measurement, characterized in that, Along the axial direction of the current meter, there are a propeller speed measuring mechanism (1), a current meter measuring mechanism (2), and a tail fin balancing mechanism (3). The propeller speed measuring mechanism (1) is used to measure the water flow velocity of the water body to be measured; The current meter measuring mechanism (2) is used to measure the water depth of the water area to be measured and to dynamically compensate the driving direction of the current meter; The tail fin balancing mechanism (3) is used to suppress the left and right swaying and up and down pitch of the flow meter, and to keep the measurement axis of the flow meter consistent with the direction of water flow; Among them, the propeller speed measuring mechanism (1) is installed on one end of the current meter measuring mechanism (2) through a bearing connection; the tail fin balancing mechanism (3) is installed on the other end of the current meter measuring mechanism (2) through a tail fin fixing nut.

2. The intelligent current meter with attitude compensation and water depth measurement according to claim 1, characterized in that, The propeller speed measuring mechanism (1) includes: The front cone mounting body (101) is mounted on the flow meter measuring mechanism (2) by bearings; the front cone mounting body (101) has a cone-shaped structure to reduce the frontal impact resistance of the water flow; The propeller body (102) is mounted on the front cone mount (101) via bearings; At least three propeller blades (103) are located circumferentially on the cross section of the propeller body (102); A magnet measuring structure (104) is mounted on the front cone mount (101) and the propeller body (102); When the propeller blade (103) is impacted and rotated by the water flow, the magnet measuring structure (104) generates a magnetic field with periodic changes in strength to measure the water flow velocity of the water area to be measured.

3. The intelligent current meter with attitude compensation and water depth measurement according to claim 2, characterized in that, The magnet measuring structure (104) includes: At least three powerful magnets (1051) are distributed along the central axis of the propeller body (102) and installed at one end of the propeller body (102) near the front cone mount (101), and corresponding to the propeller blades (103); A magnetosensitive tube (1052) is installed inside the front cone mount (101); The propeller (102) rotates under the impact of water flow, and drives the powerful magnet (1051) to rotate synchronously. During the rotation, the relative position of the powerful magnet (1051) and the magnetic tube (1052) moves closer to each other and further away from each other as the propeller blade (103) moves. When the powerful magnet (1051) rotates to a position close to the magnetic tube (1052), the magnetic field triggers the magnetic tube (1052), causing the switching state of the magnetic tube (1052) to flip. The number of flips and the pulse frequency are recorded, and the water flow velocity of the water area to be measured is obtained by the formula of water flow velocity and pulse frequency.

4. The intelligent current meter with attitude compensation and water depth measurement according to claim 3, characterized in that, The flow meter measuring mechanism (2) includes: Electronic housing mount (201) is used to carry measurement electronic unit (202); The intermediate chamber mounting body (203) is used to withstand the impact of water flow and transmit torque, ensuring coaxiality at the front and rear, structural stability and no deformation, and bearing the stable attitude unit (204). One end of the electronic compartment mounting body (201) is connected to the front cone mounting body (101) via a bearing, and the other end of the electronic compartment mounting body (201) is connected to the intermediate compartment mounting body (203) via a sealing connection structure (205).

5. The intelligent current meter with attitude compensation and water depth measurement according to claim 4, characterized in that, The measurement electronics unit (202) includes: Circuit board (2021), which is located inside the electronic compartment mounting body (201); A nine-axis attitude sensor (2022) is located inside the electronic compartment mounting body (201); the nine-axis attitude sensor (2022) is used to acquire three-dimensional spatial attitude, tilt angle, heading and motion status; A pressure sensor (2023) is mounted on the outer surface of the lower end of the electronic housing mount (201); the pressure sensor (2023) is used to collect the water pressure of the water body to be measured; A gland (2024) is installed on the outer surface of the upper end of the electronic compartment mounting body (201); the gland (2024) is used as a connector to fix, seal and protect the cable when it passes into the electronic compartment mounting body (201); Among them, the nine-axis attitude sensor (2022), pressure sensor (2023) and magnetotube (1052) are all electrically connected to the circuit board (2021).

6. The intelligent current meter with attitude compensation and water depth measurement according to claim 4, characterized in that, The stabilizing attitude unit (204) includes a column (2041) installed on the outer surface of the upper and lower ends of the intermediate chamber mounting body (203), a mounting hole (2042) opened on the column (2041), and a lead weight and measuring rope installed on the mounting hole (2042). The lead weight keeps the flow meter vertical and horizontally facing the water flow, without rolling or swinging, ensuring accurate speed measurement angle. The measuring rope has scale markings for reading the water depth to achieve layered speed measurement, and is used to withstand tension. It is straightened by the weight of the lead weight to ensure vertical lowering and no position deviation.

7. The intelligent current meter with attitude compensation and water depth measurement according to claim 4, characterized in that, The sealing connection structure (205) includes a sealing ring (2051) located near the end of the intermediate compartment mounting body (203) and a positioning groove (2052) for positioning the intermediate compartment mounting body (203) on the electronic compartment mounting body (201).

8. The intelligent current meter with attitude compensation and water depth measurement according to claim 4, characterized in that, The tail fin balancing mechanism (3) includes a rear cone mount (301), a tail fin support frame (302), at least two horizontal wings (303) and at least two vertical wings (304). The rear cone mount (301) is mounted on the end of the intermediate compartment mount (203) away from the electronic compartment mount (201); The tail fin support frame (302) is inserted into the rear cone mount (301) by means of tail fin fixing nuts (305); The horizontal wing (303) and vertical wing (304) are mounted perpendicularly to each other on the tail wing support frame (302).

9. The intelligent current meter with attitude compensation and water depth measurement according to claim 8, characterized in that, The vertical wing (304) is provided with an elongated hole (306) along the axial direction. A counterweight nut is installed in the elongated hole (306) to adjust the center of gravity of the tail wing and the whole instrument, so that the flow meter maintains a horizontal and upright attitude in the water and does not tilt or pitch.

10. A method for dynamic compensation and synchronous measurement of a flow meter, characterized in that, This method is applicable to any one of the intelligent current meters with attitude compensation and water depth measurement as described in claims 1-9, and the method includes: S1. The propeller body (102) of the propeller speed measuring mechanism (1) drives the propeller blades (103) to rotate under the impact of water flow, which in turn drives the strong magnet embedded on the propeller body to rotate together. When the magnet rotates with the propeller body, it will periodically approach and move away from the magnetic tube arranged in the front cone mounting body. When the strong magnet (1051) approaches the magnetic tube (1052), the switching state of the magnetic tube (1052) flips, triggering the IO port level of the MCU on the circuit board (2021) to change. The MCU records the trigger time of each IO port level change. During the continuous rotation of the propeller body (102), the MCU counts the number of IO port level changes within a specific time period, and calculates the time interval between two adjacent level changes through a timer, and calculates the pulse frequency of the magnetic tube (1052) based on the time interval. S2. The MCU communicates with the nine-axis attitude sensor (2022) in the measurement electronic unit (202) to read the raw data of the three-axis acceleration, three-axis gyroscope and three-axis magnetometer output by the nine-axis attitude sensor (2022) in real time, and calculates the pitch angle, roll angle, heading angle and vibration data based on the raw data to realize dynamic compensation of the flow meter driving direction; S3. Acquire real-time pressure data; The MCU is connected to the pressure sensor (2023) in the measurement electronics unit (202) via the IIC bus, and reads the total water pressure data and water temperature value output by the pressure sensor (2023) in real time to provide data support for water depth measurement; S4. When the pulse frequency does not exceed the set frequency, the MCU calculates the time interval between every two adjacent pulses in real time and obtains the real-time initial flow rate through the initial flow rate calculation algorithm. When the pulse frequency exceeds the set frequency, the MCU sets the measurement duration; selects a certain pulse falling edge as the start time of the timer, selects the falling edge after an interval of N pulses as the end time of the timer, calculates the timing time corresponding to the Nth pulse, and calculates the average initial flow velocity within the timing time interval using the average initial flow velocity calculation algorithm. S5. Normalize the triaxial acceleration data and triaxial magnetometer data obtained in S2, and calculate the pitch angle, yaw angle and roll angle respectively. S6. Transform the instrument coordinate system of the current meter to the geographic coordinate system to obtain the rotation matrix; The initial flow velocity calculated by S4 is processed by the flow velocity calculation algorithm along the propeller axis to obtain the flow velocity along the propeller axis. The real geographic flow velocity is obtained by the real geographic flow velocity calculation algorithm and the rotation matrix. The real flow velocity after attitude compensation is obtained by the real flow velocity calculation algorithm and dynamic compensation is performed. S7. Using the principle of separating dynamic and static pressure, based on the actual flow velocity obtained in S6, the total pressure data obtained in S3 is corrected, and the corrected static pressure is obtained through the correction algorithm. Based on the corrected static pressure, the actual water depth data is calculated through the static pressure water depth formula, thus realizing the synchronous measurement of flow velocity and water depth.

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