Adaptive joint control three-dimensional ocean current measurement and environment self-compensation method

Abstract

A self-adaptive joint control three-dimensional ocean current measurement and environment self-compensation method comprises the following steps: setting initial weight coefficients of four acoustic axes to be the same, receiving echo information according to a transducer, carrying out self-adaptive gain adjustment on a signal echo amplitude, calculating a re-allocation weight coefficient of joint debugging of each acoustic axis according to a gain change, and carrying out self-adaptive compensation on the self-allocation weight coefficient of the joint debugging of each acoustic axis; real-time measurement variance calculation and measurement frequency self-adaptive adjustment are carried out, joint debugging calculation is carried out again to obtain an optimized weight, a sound axis used for three-dimensional flow velocity calculation is obtained through redundancy elimination, and finally temperature and pressure compensation correction is carried out according to the obtained sound axis to obtain a flow velocity calculation result. The method has the advantages that the real-time performance of flow measurement is better, the overall coordination of a measurement system is better, the response of measurement is more flexible, the self-adaptive capability is high, and accurate and stable measurement results can be provided under various environmental conditions.

Description

Technical Field

[0001] The present invention relates to a technology in the field of ocean current detection, in particular to a three-dimensional ocean current measurement and environmental self-compensation method with spiral four-sound axis parameter adaptive joint control. Background Art

[0002] Ocean current is one of the most important and basic parameters in the marine environment. Due to the large attenuation of optical signals, the main instruments for measuring ocean currents are mechanical current meters, electromagnetic current meters, and acoustic current meters. The horizontal support structure of the existing acoustic sensing technology of current meters has low strength and is prone to vibrating under high flow rates, which affects the measurement accuracy. It is also easy to be caught by fishing nets in the ocean, causing damage to the current meter. In addition, the dual-crystal transducer has a complex structure and cumbersome preparation process. Each measurement cycle requires four acoustic axes to be measured alternately in sequence, and the measurements of each acoustic axis are not simultaneous, which affects high-speed measurements and measurement consistency. In addition, each acoustic axis lacks linkage control capabilities and is easily affected by changes in the environment and working conditions, resulting in large deviations in the measurement results, which cannot meet the high-precision and reliable measurement requirements in complex and changeable environments such as turbulence. Summary of the invention

[0003] In view of the above-mentioned deficiencies in the prior art, the present invention proposes an adaptive joint-controlled three-dimensional current measurement and environmental self-compensation method, which has the advantages of better real-time current measurement, strong overall coordination, less interference from disturbed flow, flexible measurement response, and the ability to adaptively control measurement parameters through four-axis parameter linkage, and adaptively measure flow velocity and environment.

[0004] The present invention is achieved through the following technical solutions:

[0005] The present invention relates to a spiral four-axis three-dimensional ocean current measurement system, comprising: an electrical compartment, a piezoelectric ultrasonic transducer array arranged on the top thereof, and a measurement circuit and a control circuit arranged inside thereof, wherein: the piezoelectric ultrasonic transducer array, the measurement circuit and the control circuit are connected in sequence.

[0006] The piezoelectric ultrasonic transducer array includes: a support frame and four pairs of oppositely arranged transducers, wherein: each pair of transducers is respectively arranged on the upper and lower sides of the support frame to form a measurement acoustic axis, and the four measurement acoustic axes have the same angle with the horizontal plane, which is any value between 20° and 70°; the four acoustic axes have the same length, which is 15 cm.

[0007] The measuring circuit is used for processing, amplifying, filtering and time measurement of transducer signals, and comprises four groups of identical branches, each group of branches comprising an excitation circuit, a switching circuit, an amplifying and filtering circuit and a timing circuit connected therewith.

[0008] The control circuit comprises: an FPGA circuit and a storage circuit, a communication module, an electronic compass and a battery pack respectively connected thereto.

[0009] The present invention relates to a three-dimensional ocean current measurement and environmental self-compensation method based on the above-mentioned system with adaptive joint control, comprising:

[0010] Step 1: Set the initial weight coefficients of the four acoustic axes to be the same, perform adaptive gain adjustment of the signal echo amplitude according to the echo information received by the transducer, and calculate the redistribution weight coefficient of each acoustic axis joint adjustment according to the gain change, specifically including:

[0011] 1.1 Echo monitoring: pre-set the acoustic echo signal amplitude range (0.7-1.5V) that can stabilize the results. During measurement, the echo signal amplitude of each acoustic axis is monitored in real time and recorded and saved.

[0012] 1.2 Calculate the gain. If the echo signal amplitude is less than the minimum value of the set range, the gain is increased. If it is greater than the maximum value of the set range, the gain is reduced.

[0013] 1.3 Weight redistribution: adjust the weight coefficient of each sound axis according to the gain calculation situation, and calculate and redistribute the same weight coefficients of the original four sound axes.

[0014] Step 2: Based on the redistribution weight coefficient obtained in step 1, real-time measurement variance calculation and measurement frequency adaptive adjustment are performed, and the optimized weight is obtained by joint calculation again, which specifically includes:

[0015] 2.1 Variance calculation: The initial sampling frequency is 10 Hz during measurement. Every 10 measurement data are grouped together. The measurement variance of each acoustic axis is calculated and recorded.

[0016] 2.2 Frequency calculation: when the measurement variance increases significantly to exceed the set variance threshold, it is considered that there is turbulence in the environment. The measurement frequency of each acoustic axis is adjusted jointly, and the number of measurements is automatically increased. For low flow rates, the measurement variance decreases and tends to be stable, so the measurement frequency is reduced to save energy.

[0017] 2.3 Weight adjustment: The weight coefficients of each acoustic axis after redistribution in step 1 are calculated based on the measurement variance and the threshold variance and jointly adjusted again, and normalized after adjustment.

[0018] Step 3: Eliminate redundancy based on the optimization weights obtained in step 2 to obtain the acoustic axis used for three-dimensional flow velocity calculation. Specifically, sort the optimization weights from large to small, eliminate the acoustic axis with the smallest weight as a redundant acoustic axis, and use the remaining three acoustic axes for three-dimensional flow velocity calculation.

[0019] Step 4: After the acoustic axis used for flow velocity calculation obtained in step 3 is used, temperature and pressure compensation correction is performed to obtain the flow velocity calculation result, which specifically includes:

[0020] 4.1 Real-time measurement of ambient temperature and pressure through high-precision temperature and pressure sensors;

[0021] 4.2 Correct the acoustic axis velocity component using empirical formula;

[0022] 4.3 Use the corrected optimal tri-sonic axis data to calculate the three-dimensional flow velocity. Technical Effects

[0023] Compared with the prior art, the present invention adopts four acoustic axes working simultaneously, and the structure consists of 8 independent transducers of 4 spiral acoustic axes and a four-sided pyramid layout. Compared with the traditional figure-eight acoustic axis layout, this design has higher structural strength and smaller disturbance effect, overcomes the problems of complex preparation and low yield of dual crystal transducers, saves processing costs and time, and improves the pass rate and reliability of the measurement system. The parameters of the four acoustic axes can realize adaptive linkage control to meet the needs of different measurement environments. Compared with the prior art, the present invention accurately measures the three-dimensional ocean current velocity through four-acoustic axis linkage regulation and adaptive weight adjustment, and realizes high-precision and high-stability measurement under low power consumption. The method includes four steps: adaptive control of acoustic axis gain, adaptive adjustment of measurement frequency, redundant elimination algorithm, and adaptive compensation method of environmental parameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the spiral four-axis three-dimensional ocean current measurement system of the present invention;

[0025] Figure 2 Schematic diagram of the three-dimensional time difference measurement method of seawater flow velocity of the present invention;

[0026] Figure 3 This is a schematic diagram of a circuit for three-dimensional time difference synchronous measurement of seawater velocity according to the present invention;

[0027] In the figure: 1-8 first to eighth transducers, 9 hollow support rod, 10 center fixing rod, 11 fixing seat, 12 electrical compartment, 13 switching circuit, 14 amplification and filtering circuit, 15 timing circuit, 16 excitation circuit, 17 FPGA circuit, 18 storage circuit, 19 communication module, 20 electronic compass, 21 battery pack, 22 upper transducer frame ring, 23 lower transducer frame ring;

[0028] Figure 4 This is a flow chart of the operation of the circuit for three-dimensional time difference synchronous measurement of seawater velocity of the present invention;

[0029] Figure 5 This is a flow chart of the data processing of the four-sound axis parameter adaptive joint control of the present invention;

[0030] Figure 6 This is a flow chart of step 1 of the joint control algorithm of the present invention;

[0031] Figure 7This is a flow chart of step 2 of the joint control algorithm of the present invention;

[0032] Figure 8 This is a flow chart of steps 3 and 4 of the joint control algorithm of the present invention;

[0033] Fig. 9 This is a graph of experimental data of the current meter for three-dimensional time difference synchronous measurement of seawater flow velocity according to the present invention. DETAILED DESCRIPTION

[0034] like Figure 1 As shown, this embodiment involves a single-point current meter for spiral four-axis three-dimensional time difference synchronous measurement, including: an electrical compartment 12, a piezoelectric ultrasonic transducer array arranged on the top thereof, and a measurement circuit and a control circuit arranged inside thereof, wherein: the piezoelectric ultrasonic transducer array, the measurement circuit and the control circuit are connected in sequence.

[0035] The piezoelectric ultrasonic transducer array comprises: a supporting frame and four pairs of transducers arranged opposite to each other, wherein: each pair of transducers are arranged opposite to each other on the upper and lower sides of the supporting frame to form a measuring acoustic axis.

[0036] The transducers are all axially and centrally symmetrically distributed on the support frame.

[0037] The angles between the measuring acoustic axes and the horizontal plane are the same, which are all any value between 20° and 70°, and the lengths of the four acoustic axes are the same, which is 15 cm.

[0038] The support frame comprises: a central fixing rod 11, four pairs of hollow supporting rods 9 radially arranged thereon, and peripheral reinforcement rings 22, 23.

[0039] The plane formed by the fifth to eighth transducers 5-8 is the XY plane, the projection of the hollow support rod connected to the fifth transducer on the XY plane is set as the X axis, the projection of the hollow support rod connected to the sixth transducer on the XY plane is set as the Y axis, and the central axis of the central fixed rod is set as the Z axis. The projection components of the three-dimensional flow velocity on each acoustic axis are: Where: v x 、v y 、v z are the three-dimensional flow velocities on each coordinate axis respectively.

[0040] like Figure 2As shown, the measuring circuit includes: four groups of identical branches, each group of branches includes an excitation circuit 16, a switching circuit 13, an amplifying and filtering circuit 14 and a timing circuit 15 connected thereto, wherein: the switching circuit 13 of each group of branches is respectively connected to a pair of transducers and receives the signal information of the transducers, the four groups of excitation circuits 16 simultaneously receive the control information of the FPGA circuit 17, perform signal excitation processing, and output excitation signals, the switching circuit 13 receives the control information of the FPGA circuit 17, performs signal switching processing, and outputs the switched signal to respectively excite a pair of transducers, the amplifying and filtering circuit 14 receives the signal information of the switching circuit 13, performs signal amplification and filtering processing, and outputs the amplified and filtered signal, the timing circuit 15 receives the signal information of the amplifying and filtering circuit 14, performs time measurement processing, and outputs the time measurement result.

[0041] The control circuit includes: an FPGA circuit 17 and a storage circuit 18, a communication module 19, an electronic compass 20 and a battery pack 21 respectively connected thereto, wherein: the FPGA circuit 17 is connected to the measurement circuit and receives signal information of the four groups of branch switching circuits 13, performs logic control and data processing, and outputs control instructions and processed data results; the storage circuit 18 performs data recording and storage processing according to the storage command information issued by the FPGA circuit 17, and outputs the saved data results; the communication module 19 performs data transmission processing according to the communication protocol and data information provided by the FPGA circuit 17, and outputs the communication signal results; the electronic compass 20 performs azimuth measurement processing according to the query instruction information of the FPGA circuit 17, and outputs the result of the current azimuth angle; the battery pack 21 provides stable power support for all the above circuits to ensure the normal operation of each module.

[0042] like Figure 3 As shown, this embodiment involves a three-dimensional current measurement and environmental self-compensation method based on the above-mentioned system for adaptive joint control, which specifically includes: when the current meter is placed in the seawater to be measured, the FGPA circuit 17 issues an instruction and controls 4 excitation circuits at the same time, each excitation circuit 16 sends 5-20 ultrasonic pulses to drive an ultrasonic transducer, and the sound wave enters the seawater, and the ultrasonic transducer on the same acoustic axis receives the ultrasonic pulse signal, and transmits the received ultrasonic pulse signal to the switching circuit 13, the amplifying and filtering circuit 14, the timing circuit 15, and the FPGA circuit 17 to process the sound wave propagation time to obtain the time difference related to the seawater flow rate; the four acoustic axis time differences are simultaneously obtained by the FPGA circuit 17 to obtain the flow velocity components in the orthogonal directions under the three-dimensional coordinates; combined with the geodetic coordinates measured by the electronic compass 20, the three-dimensional flow velocity vector information is converted into the flow velocity information under the geodetic coordinate system, the measurement data is stored in the storage circuit 18, and the measurement data is output through the communication circuit 19.

[0043] like Figure 4As shown, the measuring circuit first initializes the storage module, the communication module and the electronic compass, performs electronic compass measurement and receives measurement data, then cuts off the power supply of the electronic compass to reduce power consumption and sends a measurement start signal, and the four-axis measurement starts at the same time. After the measurement is completed, the received data is stored in the SD card, and the next measurement is repeated after the storage is completed.

[0044] The flow velocity components are obtained by measuring the time difference on the four acoustic axes to obtain the components of the flow velocity on the four acoustic axes, and high-stability measurement is achieved through linkage regulation among the four acoustic axes.

[0045] The initial weight coefficients of the four sound axes are equal. Suppose the four sound axes are 1, 2, 3, and 4, and their weights are W respectively. 1 , W 2 , W 3 , W 4 The weights are used to evaluate the data quality of each acoustic axis to adjust the contribution to the measurement results. The initial weights are set according to symmetry and equivalence, and meet the following conditions: in the initial state, the weights of each acoustic axis are equal to 0.25; the sum of the weights is always 1 to ensure the normalization of the measurement data. In practical applications, the weights are adjusted according to the dynamic quality of the signal and the influence of turbulence.

[0046] Step 1: When dynamically adjusting each axis, perform adaptive gain adjustment based on the signal echo amplitude: During actual measurement, monitor the change of the echo signal amplitude of each acoustic axis in real time. If it is less than the minimum value of the set range, increase the gain; if it is greater than the maximum value of the set range, reduce the gain. After the adjustment is completed, adjust the corresponding acoustic axis weight coefficient according to the gain change to obtain the redistribution weight coefficient. Where: α is the amplitude deviation adjustment coefficient, the value range is 0.1~0.3, |Mi-Mt| represents the degree to which the amplitude deviates from the target range. The adjusted weight coefficient needs to be re-normalized: Gain adjustment avoids measurement deviation caused by signal amplitude differences when measuring the acoustic axes in coordination, thus improving data reliability. At the same time, the linkage between gain adjustment and weight control can intuitively reflect the fluctuation of signal quality and realize precise coordination and control of measurement.

[0047] Step 2: Real-time variance evaluation and adaptive adjustment of measurement frequency: The system calculates the variance of each acoustic axis echo data in real time during the measurement process to evaluate the stability of the current water flow conditions. 2 Exceeding the set threshold When the system considers that there is turbulence in the environment, each sound axis is calculated and weighted according to the variance. Where: Wi' is the weight coefficient recalculated after gain adjustment, β is the turbulence correction coefficient, the value range is 0.2~0.5, is the measurement variance of the i-th acoustic axis, and after adjustment, the weight is normalized and the optimized weight is obtained: The measurement frequency of each acoustic axis is adaptively adjusted according to the linkage weight coefficient of the four acoustic axes. If turbulence causes a significant increase in variance, the system will jointly adjust the measurement frequency of each acoustic axis and automatically increase the number of measurements to ensure sufficient data to accurately reflect instantaneous changes. For low flow rates, the measurement variance tends to be stable, so the measurement frequency is reduced to save energy. The introduction of variance calculation and turbulence adaptive linkage control algorithm can effectively suppress the impact of turbulence on measurement accuracy and ensure that reliable data can still be obtained under complex flow field conditions.

[0048] Step 3: Eliminate redundant sound axes: After the linkage control among the four sound axes, the optimized weight W' of each sound axis can be obtained. i ', this coefficient can be used as a criterion for judging the quality of acoustic axis measurement data. The coefficients are sorted from large to small, and the acoustic axis with the smallest weight is eliminated as a redundant acoustic axis. The remaining three acoustic axes are used for three-dimensional flow velocity calculation.

[0049] Step 4: Adaptive control of ambient temperature and pressure parameters: Correct the filtered acoustic axis measurement data, measure the ambient temperature and pressure in real time through high-precision temperature and pressure sensors, and according to the influence of temperature and pressure, the correction formula of the acoustic axis velocity component is: C(T,P) is the speed of sound at the current temperature and pressure, which can be calculated by the empirical formula, C 0 is the reference sound velocity, and the corrected data is used for three-dimensional flow velocity calculation.

[0050] Only the best three-axis data after removing redundant channels is used for three-dimensional flow velocity calculation to ensure the system continues to operate efficiently when the acoustic axis is disturbed or fails. The three-dimensional flow velocity on each coordinate axis can be calculated from the acoustic axis components, specifically: Where: v ij It refers to the projection component of three-dimensional flow velocity on each acoustic axis.

[0051] The system automatically selects the corresponding acoustic axis calculation formula based on actual conditions.

[0052] After specific practical experiments, it takes two weeks to assemble the figure-eight structure, while the external spiral structure only takes two days. The assembled device was tested in the towing pool at different flow rates. The above device was immersed below the water surface as a whole, and the upper end was fixed to the trailer through a fixing rod. The trailer increased in speed by 0.2m / s, 0.5m / s, 0.8m / s, and increased to 4m / s, and each round trip was performed once. During towing, each speed was measured for 20s, and the output of each acoustic axis measurement value and the program automatic screening results were recorded at the same time. The measured speed was obtained by calculation and compared with the actual trailer speed for verification.

[0053] like Figure 6 As shown, the A-axis is the actual flow velocity value during the experiment, and the Y-axis is the corresponding actual measured flow velocity value, both in m / s. The red dotted line in the figure is the reference line, and the blue dots are the measured data. The measured speed is within the error range at 4 m / s. It can be seen that the present invention has good measurement accuracy, can measure rapidly changing turbulence, and can meet the needs of high-precision measurement under high flow rates.

[0054] Each transducer frame of the device is an integrated tetrahedral structure, with four hollow support rods evenly distributed at 90° around the circumference, and the outermost end is connected to the ring. The four transducers are fixed at the connection between the support rod and the ring, and the inner end of each hollow support rod is connected to the central fixed rod. The four hollow support rods and the ring form a tetrahedral structure, and the bottom surfaces of the upper transducer frame and the lower transducer frame are opposite; the angle between the hollow support rod and the central support rod is 45°-90°. The piezoelectric ultrasonic transducer array adjacent to the transducer in the upper transducer frame and the transducer directly below forms a measurement acoustic axis; the angle between each measurement acoustic axis and the base plane is the same, and they are all any same fixed value between 20°-70°. The four acoustic axes are an external spiral structure around the central fixed rod; the working plane of the ultrasonic receiver installed at the end is perpendicular to the measurement acoustic axis.

[0055] Compared with the prior art, the present invention overcomes the problems of complicated preparation process and low yield rate of the double crystal transducer of the time difference current meter with the traditional eight-shaped acoustic axis layout through adaptive adjustment of gain and weight of echo amplitude, real-time variance evaluation and measurement frequency adjustment, redundancy elimination and temperature and pressure compensation, saving processing cost and time and improving processing qualification rate; the experiment shows that the four-axis time difference can be accurately measured in parallel at a high flow rate of 4m / s, and the real-time performance of the flow measurement is better. A precise measurement method and environmental self-compensation method for three-dimensional ocean currents through linkage control between four acoustic axes are proposed, and the reliability index of each acoustic axis is calculated through a complex mathematical model, and a threshold range is set to automatically confirm and eliminate abnormal acoustic axes. It also shows that the device can measure rapidly changing turbulence. The four-sided pyramid structure has high strength and small disturbance. It can achieve accurate measurement at a high flow rate of 4m / s, which can meet the needs of high-precision measurement at high flow rates, and is particularly suitable for the fields of ocean waves, marine engineering, climate, and marine science research.

[0056] The above-mentioned specific implementation can be partially adjusted in different ways by those skilled in the art without departing from the principle and purpose of the present invention. The protection scope of the present invention shall be based on the claims and shall not be limited by the above-mentioned specific implementation. Each implementation scheme within its scope shall be subject to the constraints of the present invention.

Claims

1. A spiral four-axis three-dimensional ocean current measurement system, characterized in that: include: An electrical compartment, a piezoelectric ultrasonic transducer array disposed on the top thereof, and a measuring circuit and a control circuit disposed inside thereof, wherein: the piezoelectric ultrasonic transducer array, the measuring circuit and the control circuit are connected in sequence; The piezoelectric ultrasonic transducer array comprises: a support frame and four pairs of oppositely arranged transducers, wherein: each pair of transducers is respectively arranged on the upper and lower sides of the support frame to form a measurement acoustic axis, and the four measurement acoustic axes have the same angle with the horizontal plane and the same length.

2. A three-dimensional ocean current measurement and environmental self-compensation method based on the adaptive joint control of the system of claim 1, characterized in that: By setting the initial weight coefficients of the four acoustic axes to be the same, the signal echo amplitude adaptive gain adjustment is performed according to the echo information received by the transducer. After calculating the redistributed weight coefficients of each acoustic axis according to the gain change, real-time measurement variance calculation and measurement frequency adaptive adjustment are performed. The optimized weights are obtained by joint calculation again. The acoustic axis used for three-dimensional flow velocity calculation is obtained after redundant elimination. Finally, temperature and pressure compensation correction is performed based on the obtained acoustic axis to obtain the flow velocity calculation result.

3. The method for three-dimensional ocean current measurement and environmental self-compensation with adaptive joint control according to claim 2 is characterized in that: The redistribution weight coefficient is obtained in the following way: 1.1 Echo monitoring: pre-set the acoustic echo signal amplitude range (0.7-1.5V) that can stabilize the results. During measurement, the echo signal amplitude of each acoustic axis is monitored in real time and recorded and saved. 1.2 Calculate the gain. If the echo signal amplitude is less than the minimum value of the set range, the gain is increased; if it is greater than the maximum value of the set range, the gain is reduced; 1.3 Weight redistribution: adjust the weight coefficient of each sound axis according to the gain calculation situation, and calculate and redistribute the same weight coefficients of the original four sound axes.

4. The method for three-dimensional ocean current measurement and environmental self-compensation with adaptive joint control according to claim 2 is characterized in that: The optimization weight is obtained in the following way: 2.1 Variance calculation: The initial sampling frequency is 10 Hz during measurement. Every 10 measurement data are grouped together. The measurement variance of each acoustic axis is calculated and recorded. 2.2 Frequency calculation: when the measurement variance increases significantly to exceed the set variance threshold, it is considered that there is turbulence in the environment, and the measurement frequency of each acoustic axis is adjusted jointly to automatically increase the number of measurements. For low flow rates, the measurement variance decreases and tends to be stable, so the measurement frequency is reduced to save energy. 2.3 Weight adjustment: The weight coefficients of each acoustic axis after redistribution in step 1 are calculated based on the measurement variance and the threshold variance and jointly adjusted again, and normalized after adjustment.

5. The method for three-dimensional ocean current measurement and environmental self-compensation with adaptive joint control according to claim 2 is characterized in that: The redundant elimination means: sorting the optimization weights from large to small, eliminating the acoustic axis with the smallest weight as a redundant acoustic axis, and the remaining three acoustic axes are used for three-dimensional flow velocity calculation.

6. The method of three-dimensional ocean current measurement and environmental self-compensation with adaptive joint control according to claim 2 is characterized in that: The flow rate calculation result is obtained by the following method: 4.1 Real-time measurement of ambient temperature and pressure through high-precision temperature and pressure sensors; 4.2 Correct the acoustic axis velocity component using empirical formula; 4.3 Use the corrected optimal tri-sonic axis data to calculate the three-dimensional flow velocity.

7. The method for three-dimensional ocean current measurement and environmental self-compensation with adaptive joint control according to claim 6 is characterized in that: The plane formed by the fifth to eighth transducers is the XY plane. The projection of the hollow support rod connected to the fifth transducer on the XY plane is set as the X axis. The projection of the hollow support rod connected to the sixth transducer on the XY plane is set as the Y axis. The central axis of the central fixed rod is set as the Z axis. The projection components of the three-dimensional flow velocity on each acoustic axis are: Where: v x 、v y 、v z are the three-dimensional flow velocities on each coordinate axis respectively.

8. The method for three-dimensional ocean current measurement and environmental self-compensation with adaptive joint control according to claim 7 is characterized in that: Only the best three-axis data after removing redundant channels is used to calculate the three-dimensional flow velocity, ensuring the continuous and efficient operation of the system when the acoustic axis is disturbed or fails. The three-dimensional flow velocity on each coordinate axis can be calculated from the acoustic axis components, specifically: Where: v ij It refers to the projection component of three-dimensional flow velocity on each acoustic axis.

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