High-precision wind measurement system based on double-frequency ultrasonic waves and measurement method thereof

Abstract

The invention relates to the technical field of ultrasonic wind measurement, in particular to a high-precision wind measurement system and method based on double-frequency ultrasonic waves, and the method comprises the steps: deploying an orthogonal double-frequency ultrasonic transducer array in a horizontal plane, capturing an echo timestamp, and solving the wind speed through the dynamic changes corresponding to the high and low frequency characteristics; according to the forward and reverse wind round-trip time difference of the double-frequency ultrasonic waves on the X axis and the Y axis, the real-time temperature obtained through temperature compensation is combined, the wind speed components of the high-frequency ultrasonic waves and the low-frequency ultrasonic waves are calculated according to a forward and reverse wind formula, the X-axis final wind speed component and the Y-axis final wind speed component are obtained through weighted averaging, the wind direction angle is calculated according to an arc tangent function, and wind speed and direction results are output after quadrant correction; the wind speed and direction data obtained through calculation are preprocessed, and finally the processed data are stored in an internal storage. Double-frequency ultrasonic waves are adopted, high frequency is used for capturing rapid wind speed changes, low frequency is used for long-distance propagation to reduce environmental noise influences, the wind speed is solved in combination with a sound velocity formula, temperature compensation and a propagation equation, and high-precision measurement can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of ultrasonic wind measurement, and particularly relates to a high-precision wind measurement system based on dual-frequency ultrasonic waves and a measurement method thereof. Background Art

[0002] With the continuous progress of technology, the measurement of wind speed and wind direction has become increasingly important in many fields. The basic principle of ultrasonic wind measurement is to utilize the time difference or frequency difference that exists when ultrasonic waves propagate with the wind and against the wind in the air, and calculate the wind speed and wind direction by measuring these differences. The emergence of ultrasonic wind measurement technology provides a new idea for wind measurement. Ultrasonic waves are sound waves with a frequency higher than 20 kHz, having good directivity and penetrability. Its wind measurement principle is based on the propagation characteristics of ultrasonic waves in the air. When ultrasonic waves propagate in the direction with the wind and against the wind, due to the existence of wind speed, the propagation time will change, and the wind speed can be calculated by measuring this time difference. Early ultrasonic anemometers used single-frequency ultrasonic waves, that is, the frequency of transmitting and receiving ultrasonic waves was the same. However, single-frequency ultrasonic anemometers are prone to interference from factors such as environmental noise and temperature gradients in practical applications, resulting in limited measurement accuracy. Summary of the Invention

[0003] In view of the technical problems existing in the prior art, the present invention provides a high-precision wind measurement system based on dual-frequency ultrasonic waves and a measurement method thereof.

[0004] The technical solution for the present invention to solve the above technical problems is as follows: A high-precision wind measurement system based on dual-frequency ultrasonic waves, comprising:

[0005] An ultrasonic transceiver module: Deploy an orthogonal dual-frequency ultrasonic transducer array in the horizontal plane, capture the echo timestamps, and utilize the high- and low-frequency characteristics to cope with the dynamic changes respectively to solve the wind speed;

[0006] A wind speed and wind direction calculation module: According to the round-trip time differences of dual-frequency ultrasonic waves in the X and Y axes with the wind and against the wind, combined with the real-time temperature obtained by temperature compensation, calculate the wind speed components of high- and low-frequency ultrasounds respectively according to the with-wind and against-wind formulas, obtain the final wind speed components of the X and Y axes by weighted average, then calculate the wind direction angle according to the arctangent function, and output the wind speed and wind direction results after quadrant correction;

[0007] A data preprocessing module: Preprocess the calculated wind speed and wind direction data, and finally store the processed data in the internal memory.

[0008] In a preferred embodiment, the ultrasonic transceiver module determines the X and Y axis directions on a horizontal plane, and fixedly deploys two sets of orthogonal arrays in the X and Y axis directions respectively. Each set includes a pair of high-frequency and low-frequency ultrasonic transducers, forming a dual-frequency four-beam measurement structure. A timer interrupt program is written to alternately trigger the high-frequency and low-frequency transducers on the X and Y axes to emit. Immediately after each transducer emits, the timer starts timing, waiting for the echo signal. The rising edge of the echo signal is captured using an external interrupt, and the timestamp is recorded. The time difference (Δt) between the high-frequency and low-frequency echoes of the same beam is interpolated and calculated, and stored in a buffer array. The high-frequency sound wave is used to capture rapid wind speed changes with high dynamic response, and the low-frequency sound wave is used for long-distance propagation to reduce the influence of environmental noise. Suppose on the X axis, the propagation time of the high-frequency ultrasonic wave is t hX , and the propagation time of the low-frequency ultrasonic wave is t lX . The corresponding propagation distance is L. According to the relationship between the speed of sound, propagation time, and distance, the following formula can be obtained: The propagation distance of the high-frequency ultrasonic wave in still air: L = ct hX0 , where t hX0 is the propagation time of the high-frequency ultrasonic wave in still air. The propagation distance of the low-frequency ultrasonic wave in still air: L d = ct lX0 , where t lX0 is the propagation time of the ultrasonic wave in still air. When there is a wind speed v X , the propagation time of the ultrasonic wave will change. When the propagation time of the high-frequency ultrasonic wave is t hX , and the propagation time of the low-frequency ultrasonic wave is t lX , then for the high-frequency ultrasonic wave:

[0009] L = (c + v Xh1 )t hX1

[0010] L = (c - v Xh2 )t hX2

[0011] Where c represents the speed of sound, v Xh1 represents the wind speed when the high-frequency ultrasonic wave is in the downwind direction, t hX1 represents the propagation time of the high-frequency ultrasonic wave in the downwind direction, v Xh2 represents the wind speed when the high-frequency ultrasonic wave is in the upwind direction, t hX2 represents the propagation time of the high-frequency ultrasonic wave in the upwind direction. For the low-frequency ultrasonic wave:

[0012] L = (c + v Xl1 )t lX1

[0013] L = (c - v Xl2 )t lX2

[0014] Among them, v Xl1 represents the wind speed in the downwind direction of low-frequency ultrasonic waves, and t lX1 represents the propagation time of low-frequency ultrasonic waves in the downwind direction. v Xl2 represents the wind speed in the upwind direction of low-frequency ultrasonic waves, and t lX2 represents the propagation time of low-frequency ultrasonic waves in the upwind direction. By simultaneously solving the propagation equations of high-frequency and low-frequency ultrasonic waves, the wind speed can be obtained. When it is downwind, the simultaneous equations are:

[0015]

[0016] Based on the simultaneous equations, it can be obtained that Integrate a high-precision temperature sensor, initially smooth the data using a moving average filter, and then further suppress noise through a Kalman filter.

[0017] In a preferred embodiment, the wind speed and direction calculation module calculates the wind speed components in different directions according to the measured round-trip time difference of dual-frequency ultrasonic waves, in combination with the sound speed formula and the distance between the transducers, and obtains the round-trip time differences of dual-frequency ultrasonic waves in the X and Y axis directions. Let the round-trip times of high-frequency ultrasonic waves in the downwind and upwind directions along the X axis be t hX1 and t hX2 respectively. The round-trip times of low-frequency ultrasonic waves in the downwind and upwind directions along the X axis are t lX1 and t lX2 respectively. Similarly, the corresponding times t hY1 and t hY2 and t lY1 and t lY2 on the Y axis. Considering the influence of temperature on the sound speed, the sound speed is corrected in real time using the temperature data provided by temperature compensation, and the non-linear relationship between the sound speed and temperature is corrected in real time through the conversion function of temperature and sound speed. The calculation formula of the conversion function of sound speed and temperature is as follows:

[0018]

[0019] Among them, c represents the sound speed, T represents the actual measured temperature obtained by measuring with a platinum resistance sensor, a and b are constants, and the real-time temperature data T is obtained from temperature compensation. According to the downwind and upwind propagation formulas, the downwind speed and the upwind speed are solved respectively. Take the average of the two as the wind speed component of the X axis calculated by high-frequency ultrasonic waves Similarly, according to the above calculations, the downwind speed of low-frequency ultrasonic waves and the upwind speed can be obtained. Take the average as the wind speed component of the X axis calculated by low-frequency ultrasonic waves Perform a weighted average of the wind speed components calculated by high-frequency and low-frequency to obtain the final wind speed component of the X axis Similarly, in the same way as in the X-axis direction, calculate the wind speed components v Yh and v Yl of high-frequency and low-frequency ultrasonic waves in the Y-axis direction respectively, and finally obtain the wind speed component in the Y-axis direction According to the wind speed components in the X- and Y-axis directions, calculate the wind direction angle through the arctangent function Perform quadrant judgment and angle correction on the calculation results to ensure that the range of the wind direction angle is between 0° and 360°. Output the calculated wind speed components v X and v Y in the X- and Y-axes and the value of the wind direction angle θ as the final calculation results of the wind speed and direction

[0020] In a preferred embodiment, the data preprocessing module preprocesses the calculated wind speed and wind direction data, including data smoothing and outlier removal. Data smoothing is achieved by setting the median filtering window size m, initializing an array to store the wind direction data within the current window. When new wind direction data arrives, add it to the array. When the number of data in the array reaches the window size m, sort the wind direction data in the array, and take the median value of the sorted array as the smoothed wind direction data. Remove the first data in the array and prepare to receive the next new data. Outlier removal uses a statistical-based method. Initialize variables to store the sum S and the number of data N of the wind speed data. When new smoothed wind speed data arrives, accumulate it into S and increment N by 1. Calculate the mean of the current wind speed data and the standard deviation of the current wind speed data. For the new smoothed wind speed data, when it is considered an outlier and discarded, otherwise, it is retained as valid data, where represents the smoothed wind speed data, and μ v represents the mean. Store the processed data in the internal memory

[0021] The embodiment of the present invention also provides a measurement method for a high-precision wind measurement system based on dual-frequency ultrasonic waves, including the following steps:

[0022] S101. Deploy an orthogonal dual-frequency ultrasonic transducer array on the horizontal plane, capture the echo timestamps, and use the dynamic changes respectively corresponding to the high- and low-frequency characteristics to solve the wind speed;

[0023] S102. According to the time differences of the dual-frequency ultrasonic waves traveling back and forth in the headwind and tailwind directions on the X- and Y-axes, combined with the real-time temperature obtained by temperature compensation, calculate the wind speed components of the high- and low-frequency ultrasounds respectively according to the headwind and tailwind formulas, obtain the final wind speed components in the X- and Y-axes through weighted averaging, then calculate the wind direction angle according to the arctangent function, and output the wind speed and direction results after quadrant correction;

[0024] S103. Preprocess the calculated wind speed and wind direction data, and finally store the processed data in the internal memory.

[0025] In a preferred embodiment,

[0026] The beneficial effects of the present invention are as follows: The present invention uses dual-frequency ultrasonic waves. The high frequency is used to capture rapid wind speed changes, and the low frequency is used for long-distance propagation to reduce the influence of environmental noise. By combining the sound speed formula, temperature compensation, and propagation equation to solve the wind speed, high-precision measurement can be achieved. The transducer is alternately triggered to emit through the timer interrupt program with a 1 ms cycle to quickly obtain ultrasonic propagation time data, and the changes in wind speed and wind direction can be monitored in real time. Two sets of orthogonal arrays are deployed to form a dual-frequency four-beam measurement structure, increasing the measurement dimension and redundancy. At the same time, a variety of data processing methods are used to effectively eliminate outliers, smooth the data, and suppress noise, improving the system reliability. Considering the influence of temperature on the sound speed, a high-precision temperature sensor is used to measure the temperature in real time, and the sound speed is corrected in real time through the conversion function between the sound speed and temperature, which can adapt to different environmental temperature changes and ensure the measurement accuracy. Description of the Drawings

[0027] Figure 1 is the flowchart of the method of the present invention;

[0028] Figure 2 is the system block diagram of the present invention. Detailed Embodiments

[0029] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0030] In the description of the present application, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically defined.

[0031] In the description of the present application, the term "for example" is used to mean "serving as an example, illustration, or explanation". Any embodiment described in the present application as "for example" is not necessarily construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use the present invention. In the following description, details are set forth for purposes of explanation. It should be understood that those of ordinary skill in the art can recognize that the present invention can be implemented without the use of these specific details. In other instances, well-known structures and processes are not elaborated in detail to avoid obscuring the description of the present invention with unnecessary details. Therefore, the present invention is not intended to be limited to the embodiments shown, but rather is to be accorded the widest scope consistent with the principles and features disclosed in the present application.

[0032] As Figure 1 , this embodiment provides a measurement method for a high-precision wind measurement system based on dual-frequency ultrasonic waves, including the following steps:

[0033] S101. Deploy an orthogonal dual-frequency ultrasonic transducer array in the horizontal plane, capture the echo timestamps, and solve for the wind speed by utilizing the dynamic changes respectively corresponding to the high and low frequency characteristics.

[0034] S102. According to the round-trip time differences of the dual-frequency ultrasonic waves in the upwind and downwind directions of the X and Y axes, combined with the real-time temperature obtained through temperature compensation, calculate the wind speed components of the high and low frequency ultrasounds respectively according to the upwind and downwind formulas, obtain the final wind speed components of the X and Y axes through weighted averaging, then calculate the wind direction angle according to the arctangent function, and output the wind speed and wind direction results after quadrant correction;

[0035] S103. Preprocess the calculated wind speed and wind direction data, and finally store the processed data in the internal memory.

[0036] As Figure 2 , this embodiment provides: A high-precision wind measurement system based on dual-frequency ultrasonic waves, including:

[0037] An ultrasonic transceiver module: Deploy an orthogonal dual-frequency ultrasonic transducer array in the horizontal plane, capture the echo timestamps, and solve for the wind speed by utilizing the dynamic changes respectively corresponding to the high and low frequency characteristics;

[0038] In this embodiment, it is necessary to specifically describe the ultrasonic transceiver module. The ultrasonic transceiver module determines the X and Y axis directions on the horizontal plane, and fixedly deploys two sets of orthogonal arrays in the X and Y axis directions respectively. Each set contains a pair of high-frequency and low-frequency ultrasonic transducers, forming a dual-frequency four-beam measurement structure. Write a timer interrupt program to alternately trigger the high-frequency and low-frequency transducers on the X and Y axes to emit. For example, first X-axis high-frequency → X-axis low-frequency → Y-axis high-frequency → Y-axis low-frequency, with a cycle period of 1 ms. Immediately start the timer to time after each transducer emits, wait for the echo signal, use an external interrupt to capture the rising edge of the echo signal, record the timestamp, perform interpolation calculation (Δt) on the high-frequency and low-frequency echo time differences of the same beam, and store them in the buffer array. High-frequency sound waves are used to capture rapid wind speed changes with high dynamic response, and low-frequency sound waves are used for long-distance propagation to reduce the influence of environmental noise. Assume that on the X-axis, the propagation time of high-frequency ultrasonic waves is t hX , and the propagation time of low-frequency ultrasonic waves is t lX . The corresponding propagation distance is L. According to the relationship between the speed of sound, propagation time, and distance, the following formula can be obtained: The propagation distance of high-frequency ultrasonic waves in still air: L = ct hX0 , where t hX0 is the propagation time of high-frequency ultrasonic waves in still air. The propagation distance of low-frequency ultrasonic waves in still air: L d = ct lX0 , where t lX0 is the propagation time of ultrasonic waves in still air. When there is a wind speed v X , the propagation time of ultrasonic waves will change. When the propagation time of high-frequency ultrasonic waves is t hX , and the propagation time of low-frequency ultrasonic waves is t lX , then for high-frequency ultrasonic waves:

[0039] L = (c + v Xh1 )t hX1

[0040] L = (c - v Xh2 )t hX2

[0041] Where c represents the speed of sound, v Xh1 represents the wind speed when high-frequency ultrasonic waves are in the downwind direction, t hX1 represents the propagation time of high-frequency ultrasonic waves in the downwind direction, v Xh2 represents the wind speed when high-frequency ultrasonic waves are in the upwind direction, t hX2 represents the propagation time of high-frequency ultrasonic waves in the upwind direction. For low-frequency ultrasonic waves:

[0042] L = (c + v Xl1 )t lX1

[0043] L = (c - v Xl2)t lX2

[0044] Among them, v Xl1 represents the wind speed when the low-frequency ultrasonic wave is in the downwind direction, and t lX1 represents the propagation time of the low-frequency ultrasonic wave in the downwind direction. v Xl2 represents the wind speed when the low-frequency ultrasonic wave is in the upwind direction, and t lX2 represents the propagation time of the low-frequency ultrasonic wave in the upwind direction. By simultaneously solving the propagation equations of the high-frequency and low-frequency ultrasonic waves, the wind speed can be solved. When it is downwind, the simultaneous equations are:

[0045]

[0046] Based on the simultaneous equations, it can be obtained that Integrate a high-precision temperature sensor, use a moving average filter to initially smooth the data, and then further suppress the noise through a Kalman filter.

[0047] Wind speed and direction calculation module: According to the time differences of the dual-frequency ultrasonic waves traveling back and forth in the upwind and downwind directions on the X and Y axes, combined with the real-time temperature obtained by temperature compensation, calculate the wind speed components of the high-frequency and low-frequency ultrasounds respectively according to the upwind and downwind formulas, obtain the final wind speed components on the X and Y axes through weighted averaging, and then calculate the wind direction angle according to the arctangent function. After quadrant correction, output the wind speed and direction results;

[0048] In this embodiment, it should be specifically noted that for the wind speed and direction calculation module, the wind speed and direction calculation module calculates the wind speed components in different directions according to the measured time differences of the dual-frequency ultrasonic waves traveling back and forth, combined with the sound speed formula and the distance between the transducers, obtains the time differences of the dual-frequency ultrasonic waves traveling back and forth in the X and Y axis directions. Let the round-trip times of the high-frequency ultrasonic wave in the downwind and upwind directions on the X axis be t hX1 and t hX2 respectively, and the round-trip times of the low-frequency ultrasonic wave in the downwind and upwind directions on the X axis be t lX1 and t lX2 respectively. Similarly, the corresponding times t hY1 and t hY2 and t lY1 and t lY2 on the Y axis. Considering the influence of temperature on the sound speed, use the temperature data provided by temperature compensation to perform real-time correction on the sound speed, and through the conversion function between temperature and sound speed, real-time correct the non-linear relationship between sound speed and temperature. The calculation formula of the conversion function between sound speed and temperature is as follows:

[0049]

[0050] Among them, c represents the sound speed, T represents the actually measured temperature obtained by measuring with a platinum resistance sensor, a and b are constants, obtain the real-time temperature data T from temperature compensation, and solve the downwind speed according to the upwind and downwind propagation formulas And the wind speed against the wind direction Take the average of the two as the X-axis wind speed component for high-frequency ultrasonic wave calculation Similarly, according to the above calculations, the downwind wind speed of low-frequency ultrasonic waves can be obtained And the wind speed against the wind direction Take the average as the X-axis wind speed component for low-frequency ultrasonic wave calculation Perform weighted averaging on the wind speed components calculated by high frequency and low frequency to obtain the final X-axis wind speed component Similarly, in the same way as the X-axis direction, calculate the wind speed components v Yh and v Yl of high-frequency and low-frequency ultrasonic waves in the Y-axis direction respectively, and finally obtain the Y-axis wind speed component According to the wind speed components in the X and Y axis directions, calculate the wind direction angle through the arctangent function Perform quadrant judgment and angle correction on the calculation results to ensure that the range of the wind direction angle is between 0° - 360°, and output the calculated wind speed components v X 、v Y and the wind direction angle θ value as the final calculation results of wind speed and wind direction

[0051] Data preprocessing module: Preprocess the calculated wind speed and wind direction data, and finally store the processed data in the internal memory;

[0052] In this embodiment, it should be specifically noted that for the data preprocessing module, the data preprocessing module preprocesses the calculated wind speed and wind direction data, including data smoothing and outlier removal. Data smoothing is achieved by setting the median filtering window size m, initializing an array to store the wind direction data within the current window. When new wind direction data arrives, it is added to the array. When the number of data in the array reaches the window size m, the wind direction data in the array is sorted. Considering the periodicity of the wind direction, the data can be converted to a suitable range for sorting. For example, add 360° to all wind direction data and then sort to avoid boundary problems between 0° and 360°. Take the middle value of the sorted array as the smoothed wind direction data, remove the first data in the array, and prepare to receive the next new data. Outlier removal uses a statistical-based method. Initialize variables to store the sum S and the number of data N of the wind speed data. When new smoothed wind speed data arrives, accumulate it to S and increment N by 1. Calculate the mean of the current wind speed data and the standard deviation of the current wind speed data. For the new smoothed wind speed data, when , it is considered an outlier and discarded, otherwise, it is retained as valid data, where represents the smoothed wind speed data, and μ v represents the mean. Store the processed data in the internal memory

[0053] It should be noted that in the above embodiments, the descriptions of the various embodiments have their own emphases. For parts not described in detail in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0054] Those skilled in the art should understand that the embodiments of the present invention may provide a method, a system, or a computer program product. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0055] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows and / or blocks in the flowchart and / or block diagram, can be realized by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded computer, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate means for realizing the functions specified in Figure 1 one or more of the processes Figure 1 or a plurality of processes and / or blocks

[0056] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including instruction means, and the instruction means realizes the functions specified in Figure 1 one or more of the processes Figure 1 or a plurality of processes and / or blocks

[0057] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for realizing the functions specified in Figure 1 one or more of the processes Figure 1 or a plurality of processes and / or blocks

[0058] Although the preferred embodiments of the present invention have been described, additional changes and modifications can be made to these embodiments by those skilled in the art once they learn the basic inventive concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications that fall within the scope of the present invention.

[0059] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A high-precision wind measurement system based on dual-frequency ultrasonic waves, characterized in that, include: Ultrasonic transceiver module: An orthogonal dual-frequency ultrasonic transducer array is deployed on the horizontal plane to capture echo timestamps and solve the wind speed by using the dynamic changes of high and low frequency characteristics respectively. Wind speed and direction calculation module: Based on the round-trip time difference of dual-frequency ultrasound in the X and Y axes, combined with the real-time temperature obtained by temperature compensation, the wind speed components of high and low frequency ultrasound are calculated according to the wind and wind formulas, and the final wind speed components of the X and Y axes are obtained by weighted average. The wind direction angle is calculated according to the inverse tangent function, and the wind speed and direction results are output after quadrant correction; Data preprocessing module: preprocess the calculated wind speed and direction data, and finally store the processed data in the internal memory.

2. The high-precision wind measurement system based on dual-frequency ultrasonic waves according to claim 1, wherein, The ultrasonic transceiver module determines the X and Y axis directions on the horizontal plane, and respectively deploys two groups of orthogonal arrays in the X and Y axis directions, each group includes a high-frequency and a low-frequency ultrasonic transducer pair to form a dual-frequency four-beam measurement structure. A timer interrupt program is written to alternately trigger the high-frequency and low-frequency transducers of the X and Y axes to transmit. After each transducer is transmitted, the timer is started immediately to wait for the echo signal, and the rising edge of the echo signal is captured by using an external interrupt, and a timestamp is recorded. The high-frequency and low-frequency callback time differences of the same beam are interpolated and calculated (Δt), and stored in a cache array. The high-frequency sound wave is used for high-dynamic response to capture rapid wind speed changes, and the low-frequency sound wave is used for long-distance transmission to reduce the impact of environmental noise.

3. The high-precision wind measurement system based on dual-frequency ultrasonic waves according to claim 2, characterized in that, The calculation of the wind speed is set in the X-axis direction. The propagation time of the high-frequency ultrasonic wave is t hX , and the propagation time of the low-frequency ultrasonic wave is t lX . The corresponding propagation distance is L. According to the relationship between the sound speed, propagation time, and distance, the following formula can be obtained: The propagation distance of the high-frequency ultrasonic wave in still air: L = ct hX0 , where t hX0 is the propagation time of the high-frequency ultrasonic wave in still air. The propagation distance of the low-frequency ultrasonic wave in still air: L d = ct lX0 , where t lX0 is the propagation time of the ultrasonic wave in still air. When there is a wind speed v X , the propagation time of the ultrasonic wave will change. When the propagation time of the high-frequency ultrasonic wave is t hX and the propagation time of the low-frequency ultrasonic wave is t lX , then for the high-frequency ultrasonic wave: L = (c + v Xh1 )t hX1 L = (c - v Xh2 )t hX2 where c represents the speed of sound, v Xh1 represents the wind speed of high-frequency ultrasonic waves in the downwind direction, t hX1 represents the propagation time of high-frequency ultrasonic waves in the downwind direction, v Xh2 represents the wind speed of high-frequency ultrasonic waves in the upwind direction, t hX2 represents the propagation time of high-frequency ultrasonic waves in the upwind direction. For low-frequency ultrasonic waves: L = (c + v Xl1 )t lX1 L = (c - v Xl2 )t lX2 Among them, v Xl1 represents the wind speed in the downwind direction of the low-frequency ultrasonic wave, and t lX1 represents the propagation time of the low-frequency ultrasonic wave in the downwind direction, v Xl2 represents the wind speed in the upwind direction of the low-frequency ultrasonic wave, and t lX2 represents the propagation time of the low-frequency ultrasonic wave in the upwind direction.

4. The high-precision wind measurement system based on dual-frequency ultrasonic waves according to claim 3, characterized in that, By combining the propagation equations of high-frequency and low-frequency ultrasound, the wind speed can be solved. When the wind is blowing in the right direction, the combined equations are: Available based on the simultaneous equations Integrated high-precision temperature sensor, initially smooth the data using moving average filtering, and then further suppress the noise through Kalman filtering.

5. The high-precision wind measurement system based on dual-frequency ultrasonic waves according to claim 1, characterized in that, The wind direction calculation module calculates the wind speed components in different directions based on the measured round-trip time difference of the dual-frequency ultrasonic wave, in combination with the sound speed formula and the distance between the transducers, and obtains the round-trip time differences of the dual-frequency ultrasonic wave in the X and Y axis directions. Let the round-trip times of the high-frequency ultrasonic wave in the downwind and upwind directions of the X axis be t hX1 and t hX2 , respectively. The round-trip times of the low-frequency ultrasonic wave in the downwind and upwind directions of the X axis are t lX1 and t lX2 , respectively. Similarly, the corresponding times t hY1 , t hY2 , t lY1 , and t lY2 on the Y axis. Considering the influence of temperature on the sound speed, the sound speed is corrected in real time using the temperature data provided by the temperature compensation, and the non-linear relationship between the sound speed and temperature is corrected in real time through the conversion function of temperature and sound speed. The calculation formula of the conversion function of sound speed and temperature is as follows: Wherein, c represents the speed of sound, T represents the actual measured temperature measured by a platinum resistance sensor, and a and b are constants.

6. The high-precision wind measurement system based on dual-frequency ultrasonic waves according to claim 5, characterized in that The calculation of the wind speed component is carried out by obtaining the real-time temperature data T from the temperature compensation, and solving the downwind speed and the upwind speed respectively according to the downwind and upwind propagation formulas. and the upwind speed Take the average of the two as the X-axis wind speed component calculated by high-frequency ultrasonic waves. Similarly, according to the above calculation, the downwind speed of low-frequency ultrasonic waves can be obtained. and the upwind speed Take the average as the X-axis wind speed component calculated by low-frequency ultrasonic waves. Perform a weighted average of the wind speed components calculated by high-frequency and low-frequency to obtain the final X-axis wind speed component. Similarly, in the same way as the X-axis direction, calculate the wind speed components vy and vy of high-frequency and low-frequency ultrasonic waves in the Y-axis direction respectively. Yh and vy Yl , and finally obtain the Y-axis wind speed component. According to the wind speed components in the X and Y axis directions, calculate the wind direction angle through the arctangent function. Judge the quadrant of the calculation result and correct the angle to ensure that the range of the wind direction angle is between 0° and 360°. Output the calculated X and Y axis wind speed components v X 、v Y and the wind direction angle θ value as the final calculation result of the wind speed and direction.

7. A high-precision wind measurement system based on dual-frequency ultrasonic waves according to claim 1, characterized in that, The data preprocessing module preprocesses the calculated wind speed and wind direction data, including data smoothing and outlier removal. For data smoothing, by setting the median filter window size m, an array is initialized to store the wind direction data within the current window. When new wind direction data arrives, it is added to the array. When the number of data in the array reaches the window size m, the wind direction data in the array is sorted, and the median value of the sorted array is taken as the smoothed wind direction data. The first data in the array is removed, and it is ready to receive the next new data. For outlier removal, a statistical-based method is used. Variables are initialized to store the sum S and the number of data N of the wind speed data. When new smoothed wind speed data arrives, it is accumulated into S, and N is incremented by 1. The mean value of the current wind speed data is calculated, and the standard deviation of the current wind speed data is calculated. For the new smoothed wind speed data, when it is considered an outlier and discarded, otherwise, it is retained as valid data. Among them, represents the smoothed wind speed data, and μ v represents the mean value. The processed data is stored in the internal memory.

8. A measurement method of a high-precision wind measurement system based on dual-frequency ultrasonic waves, applied to a high-precision wind measurement system based on dual-frequency ultrasonic waves according to any one of claims 1-7, characterized in that, The following steps are involved: S101. Deploy an orthogonal dual-frequency ultrasonic transducer array in a horizontal plane, capture echo timestamps, and solve the wind speed by using the dynamic changes of high and low frequency characteristics respectively. S102, according to the time difference of the dual-frequency ultrasonic wave in the X and Y axes in the forward and reverse winds, combined with the real-time temperature obtained by temperature compensation, the wind speed components of the high and low frequency ultrasonic waves are calculated according to the forward and reverse wind formulas, the final wind speed components of the X and Y axes are obtained by weighted average, and the wind direction angle is calculated according to the inverse tangent function, and the wind speed and direction results are output after quadrant correction; S103, pre-processing the calculated wind speed and direction data, and finally storing the processed data in an internal memory.

Images