JP2009229256A - Ultrasonic wind speed/direction apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic wind speed/direction apparatus, capable of accurately measuring the speed and the direction of wind, while eliminating wrong measurements caused by disturbance of the wind, even when the speed of the wind parallel to the detection direction of a propagation speed is to be measured. <P>SOLUTION: This ultrasonic wind speed/direction apparatus is equipped with an ultrasonic wind vane anemometer, in which a plurality of wave transmission devices (A11, A12, A21, A22), each having a lateral effect type piezoelectric oscillation element, by using a cylindrical expanding oscillation are arranged so as to mutually transmit an ultrasonic signal. The ultrasonic wind speed/direction apparatus comprises: a means for measuring a propagation time period of a bidirectional ultrasonic signal, between the wave transmission devices in all of the combinations of pairs of the wave transmission devices; a means for computing n×(n-1)/2 wind direction/speed vectors, in terms of the number n of wave transmission devices, on the basis of the measured propagation time period of the ultrasonic signal; a means for excluding a wind direction value and a wind speed value, with each being different so as to be not lower than a predetermined threshold in the computed wind direction/speed vectors; and a means for generating a wind direction/speed value for the output, on the basis of the wind direction/speed value except the excluded wind direction/speed values. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a wind direction and wind speed device using ultrasonic waves, and in particular, in a plurality of transducers arranged so as to be able to transmit and receive ultrasonic signals, the bidirectional ultrasonic signal transmission time between the transducers is measured to measure the wind velocity. Further, the present invention relates to an ultrasonic wind direction and wind speed device for obtaining a wind direction.

The principle of the ultrasonic anemometer is described in Non-Patent Document 1 described below, and conventionally, for example, the ultrasonic anemometer shown in FIG. 7 has been used.
This ultrasonic anemometer includes four transducers for transmitting and receiving ultrasonic pulses at 90 ° intervals, each of which includes a longitudinal-effect piezoelectric vibrator using the length vibration of a cylinder shown in FIG. 7 (a). Provided, the transducers on the diagonal line are arranged opposite to each other so as to be able to transmit and receive ultrasonic waves, and ultrasonic signals are alternately transmitted from the transducers arranged opposite to each other. The ultrasonic wave propagation time between the transmitter and the receiver is measured by receiving the wave, and the wind direction wind speed value is calculated from two orthogonal wind speed values obtained thereby.

  This will be explained with reference to FIG. 8. In FIG. 8, the transmitter / receiver (A11, A12) provided opposite to each other and the transmitter / receiver (A21, A22) arranged opposite to each other so as to be orthogonal thereto are arranged. Connected to the signal processing circuit 5, the signal processing circuit 5 alternately supplies pulse signals to the opposing transducers (A 11 and A 12, A 21 and A 22) to generate ultrasonic signals, Two-way transit time by receiving the ultrasonic signal with the other transmitter / receiver (the time when the ultrasonic signal arrives from one transmitter / receiver to the other transmitter / receiver, that is, the time when the ultrasonic signal was generated) And ultrasonic signal propagation time, which is the time difference between the received time and the received time.

  Ultrasound propagates in normal temperature air at a speed of 340 m / sec, just like normal sound waves.If it propagates in the same direction as the air flow, it becomes faster by the wind speed, and if it propagates in the opposite direction, it slows by the wind speed. From the propagation time t11 = L / (C + Vx) from the transducer A11 to A12 and the propagation time t12 = L / (C−Vx) from the transducer A12 to A11, the wind speed Vx is expressed by the following equation (1). To calculate.

Accordingly, the wind speed Vx can be obtained by measuring and calculating the propagation times t11 and t12 in the signal processing circuit 2a.
Similarly, the wind speed Vy is expressed by the following equation (2) from the propagation times t21 and t22 of the opposing ultrasonic transducers A21 and A22.

そして、この演算された風速ＶxとＶyにより風速(Ｖ)および風向(θ)を次式により算出する。

Then, the wind speed (V) and the wind direction (θ) are calculated from the calculated wind speeds Vx and Vy by the following equations.

Hanafusa Tatsuo, Fujitani Tokunosuke, Kobori Yasuhiro, Mitsuda Nei: “On the New Ultrasonic Wind Velocity Thermometer” Meteorological Research Institute Vol. 33, No. 1-19, March 1982

  However, the conventional ultrasonic anemometer measures the wind speed parallel to the propagation velocity detection direction, and the presence of the transducer itself makes the wind flow turbulent in this direction noticeable and accurate. The wind direction and wind speed could not be measured.

For example, in FIG. 8, assuming that the propagation velocity detection direction is between A11 and A12 and the wind is blowing from the A11 side in the same direction, the turbulence of the wind flow from A11 to A12 becomes remarkable. As shown in FIG. 9, the flow pattern formed after the uniform flow passes through the cylinder is the number of lay nozzles (Re = Ud / v, U: cross-sectional average flow velocity, d: diameter of the circular tube, v: movement It can be understood from the following change depending on the viscosity coefficient).
In the range of Re ≦ 1, the flow is steady and symmetric along the cylinder,
In the range of Re = 1 to 10, the flow is still steady, but a pair of vortices (twin vortices) is formed downstream of the cylinder,
In the range of Re = 10 to 10 ^2, the vortex pair appears vibration downstream thereof becomes increasingly, Karman vortex street is formed,
In the range of Re = 10 ² to 10 ⁵ , the vortex street is disturbed to form an unsteady and non-periodic wake,
In the range of Re> 10 ^5, the wake becomes a complete turbulent state.

  The present invention has been made in view of such circumstances, and even when measuring the wind speed parallel to the propagation speed detection direction, the wind direction wind speed value is accurately measured without erroneous measurement due to the turbulence of the wind flow. An object of the present invention is to provide an ultrasonic wind speed device that can be used.

  In order to solve the above-mentioned problems, an ultrasonic wind direction wind speed device according to the present invention includes a plurality of transducers each including a piezoelectric transducer having a lateral effect utilizing the expansion vibration of a cylinder so that ultrasonic signals can be transmitted and received. An ultrasonic anemometer, which transmits the ultrasonic signal from one of the transducers and receives the signals at the other transducers, sequentially switches the transducers that transmit the ultrasonic signals. By repeating, measurement means for measuring the bidirectional ultrasonic signal propagation time between the transducers for all combinations of transducers, and transmitting and receiving waves from the ultrasonic signal propagation time measured by the measurement means Wind direction and wind speed vector calculating means for calculating n · (n−1) / 2 wind directions and wind speed vectors for the number n, and among the calculated wind directions and wind speed vectors, wind direction values and wind speeds differing by a predetermined threshold value or more. Calculation excluding values And excluding means is characterized by comprising an output value generating means for generating a Wind value for output on the basis of the wind speed and direction values other than wind direction and speed values that were excluded by the calculation value excluding means.

  Therefore, by repeating the operation of transmitting an ultrasonic signal from one of the transducers and receiving the waves with the remaining other transducers by sequentially switching the transducers that transmit the ultrasonic signals by the measuring means, Two-way ultrasonic signal propagation time between the transducers is measured for all combinations of transducers, and the number of transmitters / receivers is calculated by the wind direction / wind velocity vector calculation means based on the ultrasonic signal propagation time obtained thereby. n · (n−1) / 2 wind direction wind speed vectors for n are calculated. The calculated value excluding means excludes the wind direction value and the wind speed value that differ from the calculated wind direction wind speed vector by a predetermined threshold value or more, and the output value generating means excludes the wind direction wind speed other than the excluded wind direction wind speed value. Since the wind direction value for the output wind direction is generated based on the value, the turbulence of the wind flow in a certain direction appears prominently, and the measurement of the ultrasonic signal propagation time between the paired transducers in that direction may be affected. Even in such a case, out of the calculated wind direction and wind speed vectors, greatly deviated wind direction values and wind speed values are excluded, and the output wind direction wind speed value can be accurately generated from the remaining wind direction wind speed values.

  Here, the measuring means for measuring the two-way ultrasonic signal propagation time between the transmitter and the receiver for all combinations of the transmitter and the receiver transmits the ultrasonic signal from one of the transmitter and the receiver as described above. Even if the operation of receiving signals with the other transducers is measured by switching the transducers that transmit ultrasonic signals sequentially and repeating, the ultrasonic signals are transmitted from one of the transducers. Then, the operation of receiving the signal with one of the remaining transmitters / receivers is measured by sequentially switching the transmitter / receiver for receiving the waves and repeating the operation by sequentially switching the transmitter / receiver for transmitting the ultrasonic signal. May be.

  Further, the output value generation means may be configured to generate wind direction wind speed values for output by averaging wind direction wind speed values other than the wind direction wind speed values excluded by the calculated value exclusion means in consideration of measurement errors. Good. Since the wind direction value of the wind direction / wind velocity vector needs to form a reference, it is preferable to use a wind direction value corrected to the true direction.

  As described above, according to the present invention, there is provided an ultrasonic anemometer in which a plurality of transducers each including a piezoelectric transducer having a lateral effect utilizing the expansion vibration of a cylinder are arranged so as to be able to transmit and receive an ultrasonic signal. The bidirectional ultrasonic signal propagation time between the transducers is measured for all combinations of transducers used, and n · (n for the number of transducers n is determined from the measured ultrasonic signal propagation time. -1) / 2 wind direction wind speed vectors (wind speed value and wind direction value) are obtained, and among the calculated wind direction wind speed vectors, wind direction wind speed values that differ by a predetermined threshold value or more are excluded, and the remaining wind directions Since the wind speed value for output is generated from the wind speed value, the wind direction wind speed value can be accurately measured even when the transducer itself is present and the wind flow is disturbed and there is a significantly different wind direction wind speed value. It becomes possible to do.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, the best embodiment of the invention will be described with reference to the accompanying drawings.

1 and 2 show an ultrasonic anemometer 1 according to the present invention.
In this example, a case where the number of transducers is four is shown, and each transducer (transducer: A (A11, A12, A21, A22)) is as shown in FIG. The piezoelectric vibrator 2 having a lateral effect utilizing the expansion vibration of the cylinder is provided, and is attached via the arm 4 at an interval of 90 degrees with respect to the center of the upper portion of the base 3, so that the adjacent transducers are equidistant. Is placed at the apex of the square.

  Therefore, the ultrasonic signal oscillated from each transmitter / receiver A spreads in all directions and is transmitted to the remaining other transmitters / receivers. For each of the paths (paths between adjacent transducers (R1, R2, R3, R4) and diagonal paths (R5, R6)), ultrasonic signals can be measured in both directions. I have to.

  Each transducer A (A11, A12, A21, A22) is electrically connected to a signal processing circuit 5 as shown in FIG. 3, and the signal processing circuit 5 is based on a program recorded in advance. Ultrasound signals are transmitted and received between the paired transducers that make up the path, and the bidirectional transit time (the time it takes for one ultrasound to reach the other transducer) is measured on each path. Then, the wind direction wind speed value for output is calculated based on the following method shown in FIG. The signal processing circuit 5 may be provided integrally with the anemometer 1 or may be configured separately.

  First, since the wind direction anemometer 1 is generally installed in a fixed direction, here, among the four transducers (A11, A22, A12, A21) arranged at the apex of the square, A11 , A12 are set so as to coincide with the reference (north-south) direction, that is, the true orientation (step S1).

In the anemometer 1 installed in this way, first, the bidirectional ultrasonic signal propagation time between the paired transducers in each path is measured (step S2). The measurement of the two-way ultrasonic signal propagation time between the transmitters and receivers in the combination of all the transmitters and receivers is performed by transmitting an ultrasonic signal from one of the transmitters and receiving the other transmitters and receivers. Even if the operation of receiving the wave is measured by sequentially switching and repeating the transmitter / receiver that transmits the ultrasonic signal, the ultrasonic signal is transmitted from one of the transmitter / receiver and the remaining 1 Thus, the operation of receiving waves may be measured by sequentially switching and repeating the transducers that receive the waves, and switching and repeating the transducers that transmit the ultrasonic signals.

  Then, wind speeds (Vx, Vy) in two orthogonal axes are obtained based on the measured ultrasonic signal propagation time (step S3), and the wind direction wind speed vector (wind speed (V), wind direction) is calculated from the wind speeds in the two orthogonal axes. (Θ)) is calculated (step S4). Thereafter, the wind direction (θ) of the wind direction wind speed vector is corrected and replaced with the wind direction (θ0) with respect to the true direction (north and south) (step S5).

In FIG. 3, Vx ¹¹ ₁₂ is obtained by A11 transmission A12 reception and A12 transmission A11 reception (A11 → A12) axial wind speed, and Vy ¹¹ ₁₂ is obtained by A22 transmission A21 reception and A21 transmission A22 reception (A22 → A21). ) Axial wind speed, V ¹¹ ₁₂ , θ ¹¹ ₁₂ is the combined wind speed and wind direction of Vx ¹¹ ₁₂ and Vy ¹¹ ₁₂ , θ ₀ ¹¹ ₁₂ is the wind direction corrected to the reference (north-south) direction of θ ¹¹ ₁₂ is there. Vx ¹¹ ₂₁ is the wind speed in the axial direction obtained by A11 transmission A21 reception and A21 transmission A11 reception (A11 → A21), and Vy ¹¹ ₂₁ is obtained by A22 transmission A11 reception and A11 transmission A22 reception (A22 → A11) axis. The wind speed in the direction, V ¹¹ ₂₁ , θ ¹¹ ₂₁ is the wind speed and the wind direction obtained by combining Vx ¹¹ ₂₁ and Vy ¹¹ _21, and θ ₀ ¹¹ ₂₁ is the wind direction obtained by correcting θ ¹¹ ₂₁ in the reference (north-south) direction.
Next symbol Vx ²¹ ₂₂ , Vy ²¹ ₂₂ , V ²¹ ₂₂ , θ ²¹ ₂₂ , θ ₀ ²¹ ₂₂ , Vx ¹¹ ₂₂ , Vy ¹¹ ₂₂ , V ¹¹ ₂₂ , θ ¹¹ ₂₂ , θ ₀ ¹¹ ₂₂ , Vx ²¹ ₁₂ , Vy ²¹ ₁₂ , V ²¹ ₁₂ , θ ²¹ ₁₂ , θ ₀ ²¹ ₁₂ , Vx ²² ₁₂ , Vy ²² ₁₂ , V ²² ₁₂ , θ ²² ₁₂ , θ ₀ ²² ₁₂ have the same meaning.

  Then, the processing of the above steps S3 to S5 is performed for each pair of transceivers (for each path), and a total of six (n * (n−1) / 2: n = 4) wind direction wind speed vectors ( A wind speed (V) and a wind direction (θ0)) are obtained (step S6).

Therefore, when there is no turbulent flow, the wind speed and the wind direction are generally expressed by the following equations.

  Then, the difference between each wind direction is calculated | required, and when the difference is larger than a predetermined threshold value, it excludes. Similarly, a difference between wind speeds is obtained, and when the difference is larger than a predetermined threshold, it is excluded. And the wind direction wind speed value for an output is calculated | required from the remaining wind direction wind speed value (wind direction value, wind speed value). That is, the average value of the wind direction and the wind speed is obtained from the remaining wind direction and wind speed, respectively, and this is used as the final wind direction wind speed value for output (step S7). If the difference is within the threshold value in each of the wind direction and the wind speed, an average value of all six values is obtained.

Based on the above method, as shown in FIG. 5, when the wind direction when the wind is blowing from the X-axis direction is measured, in this state, when there is no turbulent flow, the wind speed and the wind direction are measured. Should be as follows:

However, in practice, the transducer A11 itself, a turbulent flow as shown in FIG. 5 is generated, different V ¹¹ ₁₂ between the A11 → A12, θ ₀ ¹¹ ₁₂ other wind speed, and wind direction value. Therefore, in this case, the final wind speed (V) and wind direction (θ) for output are calculated from the remaining five values excluding V ¹¹ ₁₂ and θ ₀ ¹¹ ₁₂ .

Specifically, the difference between the wind directions is obtained, and if the difference is within the threshold value, all six wind directions are averaged to obtain the final wind direction. If the difference between the wind directions is greater than the threshold value, The wind direction average value is calculated from the remaining wind direction values by excluding the greatly different wind direction values, and this is used as the final output wind direction.
Also, the difference between the respective wind speeds is obtained, and if the difference is within the threshold value, all six wind speeds are averaged to obtain the final wind speed. If the difference between the wind speeds is greater than the threshold value, the difference is greatly different. The average value of the wind speed is calculated from the remaining wind speed values excluding the wind speed value, and this is used as the final output wind speed.

In addition, as shown in FIG. 6, when the wind is blowing from the direction of 45 degrees with respect to the north and south, the wind speed and direction should be as follows when there is no turbulent flow. .

However, in practice, the A11 and A21 itself, a turbulent flow as shown in FIG. 5 is generated, A11 → A22 between and A21 → A12 between the V ¹¹ _22, θ ₀ ¹¹ ₂₂ and V ²¹ _12, θ ₀ ²¹ ₁₂ Is different from other wind speeds and directions. Therefore, in this case, the wind speed (V) and the wind direction (θ) are calculated from the remaining four values excluding V ¹¹ ₂₂ and θ ₀ ¹¹ ₂₂ and V ²¹ ₁₂ and θ ₀ ²¹ ₁₂ .

As described above, even when the wind blows from any direction, the wind direction wind speed value for final output can be obtained by excluding significantly different wind direction wind speed values and averaging the remaining wind direction wind speed values. Therefore, even when the turbulence of the wind flow becomes significant due to the presence of the transducer itself, it is possible to measure an accurate wind direction and wind speed value.
In the above example, an example in which there are four transducers A (n = 4) is shown, but the present invention is not limited to this, and in the case where there are three or five transducers. Alternatively, the above-mentioned technical idea may be adopted to measure the wind direction and wind speed value.

FIG. 1 is a view showing an anemometer for use in the present invention having four transducers, wherein (a) is a plan view thereof and (b) is a side view thereof. FIG. 2 (a) is a conceptual diagram showing a transducer having a lateral effect piezoelectric vibrator using the expansion vibration of a cylinder, and FIG. 2 (b) is a layout of four transducers and a transmission / reception wave. It is explanatory drawing which shows the path | route formed by the combination of a pair of vessels. FIG. 3 is a configuration diagram showing an ultrasonic wind direction and wind speed device including four transducers each including a piezoelectric vibrator having a lateral effect using the expansion vibration of a cylinder and a signal processing circuit connected thereto. . FIG. 4 is a flowchart for explaining a method of calculating the wind direction wind speed value for output. FIG. 5 is an explanatory diagram for explaining an example when wind is blowing from the X-axis direction. FIG. 6 is an explanatory diagram for explaining an example when the wind is blowing from a direction of 45 degrees with respect to the north and south. FIG. 7 (a) is a conceptual diagram showing a conventional transducer having a longitudinal-effect piezoelectric vibrator utilizing the length vibration of a cylinder, and FIG. 7 (b) is formed by opposing transducers. It is explanatory drawing which shows the route | root performed. FIG. 8 is a configuration diagram showing an ultrasonic wind direction and wind speed device provided with a conventional transducer and a signal processing circuit connected thereto. FIG. 9 is a diagram illustrating a flow pattern that varies depending on the number of ray nozzles (Re).

Explanation of symbols

A (A11, A12, A21, A22) Transceiver 1 Ultrasonic anemometer

Claims (4)

It is equipped with an ultrasonic anemometer in which a plurality of transducers equipped with a lateral-effect piezoelectric vibrator using the expansion vibration of a cylinder are arranged so as to be able to send and receive ultrasonic signals to each other,
The operation of transmitting an ultrasonic signal from one of the transducers and receiving it by the remaining other transducers is performed by sequentially switching the transducers that transmit the ultrasonic signals to repeat the operation of all the transducers. A measuring means for measuring a bidirectional ultrasonic signal propagation time between a transmitter and a receiver for a combination of pairs;
Wind direction and wind speed vector calculating means for calculating n · (n−1) / 2 wind direction and wind speed vectors for the number of transducers n from the ultrasonic signal propagation time measured by the measuring means;
Of the calculated wind direction wind speed vectors, calculated value excluding means for excluding wind direction values and wind speed values that differ by a predetermined threshold value or more;
An ultrasonic wind direction wind speed device comprising: output value generation means for generating a wind direction wind speed value for output based on a wind direction wind speed value other than the wind direction wind speed value excluded by the calculated value exclusion means. Equipped with an ultrasonic anemometer in which a plurality of transducers equipped with a piezoelectric transducer with a lateral effect utilizing the expansion vibration of a cylinder are arranged so as to be able to send and receive ultrasonic waves to each other,
The transmitter / receiver that transmits an ultrasonic signal from one of the transducers and repeats the operation of receiving the signal by one of the remaining transducers by sequentially switching the transducers to be received. By sequentially switching and repeating, measurement means for measuring the bidirectional ultrasonic signal propagation time between the transmitter and receiver for the combination of all the transmitter and receiver,
Wind direction and wind speed vector calculating means for calculating n · (n−1) / 2 wind direction and wind speed vectors for the number of transducers n from the ultrasonic signal propagation time measured by the measuring means;
Of the calculated wind direction wind speed vectors, calculated value excluding means for excluding wind direction values and wind speed values that differ by a predetermined threshold value or more;
An ultrasonic wind direction wind speed device comprising: output value generation means for generating a wind direction wind speed value for output based on a wind direction wind speed value other than the wind direction wind speed value excluded by the calculated value exclusion means. The output value generation means averages wind direction wind speed values other than the wind direction wind speed value excluded by the calculated value exclusion means, and generates the output wind direction wind speed value. The ultrasonic wind direction wind speed device according to 2. The ultrasonic wind direction wind speed apparatus according to claim 1 or 2, wherein the calculated wind direction value of each wind direction wind speed vector is corrected to a wind direction value with respect to a true direction.

Images