Ultrasonic anemometer and program

Abstract

To provide an ultrasonic anemometer capable of improving measurement accuracy. [Solution] The ultrasonic anemometer 100 comprises an ultrasonic oscillator that emits ultrasonic waves, an ultrasonic receiver that receives ultrasonic waves emitted from the ultrasonic oscillator, and a control circuit that controls the emission of ultrasonic waves by the ultrasonic oscillator and processes data received by the ultrasonic receiver. The control circuit calculates the variance of the first received data received by the ultrasonic receiver when the ultrasonic oscillator is not emitting ultrasonic waves, and determines that a high wind speed state is in which the wind speed is higher than a first reference value if the value of the variance exceeds a first determination threshold.

Description

[Technical Field]

[0001] This disclosure relates to an ultrasonic anemometer and a program. [Background technology]

[0002] As an ultrasonic wind direction, wind speed, and temperature measuring device, the device described in Patent Document 1 is known. The device described in Patent Document 1 comprises an ultrasonic transmitter that transmits ultrasonic waves into the surroundings, a group of ultrasonic receivers consisting of pairs of ultrasonic receivers placed opposite each other with the ultrasonic transmitter in between, arranged in at least two directions around the ultrasonic transmitter, propagation time detection means for measuring the propagation time from when the ultrasonic transmitter transmits ultrasonic waves until each ultrasonic receiver receives those ultrasonic waves, and calculation means for calculating the ambient temperature, wind direction, and wind speed based on the detected propagation time values, and determining whether or not there is an abnormality in the device.

[0003] As an ultrasonic wind direction and speed device, the device described in Patent Document 2 is known. The device described in Patent Document 2 includes an ultrasonic wind direction and speed meter in which a plurality of transducers equipped with a piezoelectric transducer with a transverse effect that utilizes the expansion vibration of a cylinder are arranged so that ultrasonic signals can be transmitted to and received from each other. This device includes a measuring means for measuring the bidirectional ultrasonic signal propagation time between transducers for all pairs of transducers by sequentially switching the transducers that emit ultrasonic signals and repeating the operation of emitting ultrasonic signals from one transducer to receiving them from the other transducers; a wind direction and speed vector calculation means for calculating n·(n-1) / 2 wind direction and speed vectors for the number of transducers n from the ultrasonic signal propagation time measured by the measuring means; a calculation value exclusion means for excluding wind direction and speed values ​​that differ by more than a predetermined threshold from the calculated wind direction and speed vectors; and an output value generation means for generating output wind direction and speed values ​​based on wind direction and speed values ​​other than those excluded by the calculation value exclusion means. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 5-307087 [Patent Document 2] Japanese Patent Publication No. 2009-229256 [Overview of the project] [Problems that the invention aims to solve]

[0005] In ultrasonic anemometers, determining whether the detected value is abnormal is a crucial task.

[0006] This disclosure aims to provide an ultrasonic anemometer and program that can determine whether a detected value is abnormal and can improve measurement accuracy. [Means for solving the problem]

[0007] The ultrasonic anemometer according to this disclosure comprises an ultrasonic oscillator that emits ultrasonic waves, an ultrasonic receiver that receives ultrasonic waves emitted from the ultrasonic oscillator, and a control circuit that controls the emission of ultrasonic waves by the ultrasonic oscillator and processes data received by the ultrasonic receiver. The control circuit calculates the variance of first received data received by the ultrasonic receiver when the ultrasonic oscillator is not emitting ultrasonic waves, and determines that a high wind speed state is in which the wind speed is higher than a first reference value if the value of the variance exceeds a first determination threshold. [Effects of the Invention]

[0008] This disclosure provides an ultrasonic anemometer and program that can determine whether a detected value is abnormal and can improve measurement accuracy. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic cross-sectional view illustrating an ultrasonic anemometer according to an embodiment. [Figure 2]A schematic diagram showing the arrangement of a plurality of ultrasonic transceivers and an example of a vector between these plurality of ultrasonic transceivers. [Figure 3] A block diagram illustrating the hardware configuration of an ultrasonic wind speed meter according to an embodiment. [Figure 4] A graph showing an example of the relationship between a set wind speed and a dispersion value. [Figure 5] A flowchart showing an example of a control processing procedure (part 1) in an ultrasonic wind speed meter. [Figure 6] A flowchart showing an example of a control processing procedure (part 2) in an ultrasonic wind speed meter. [Figure 7] A flowchart showing an example of a control processing procedure (part 3) in an ultrasonic wind speed meter. [Figure 8] A flowchart showing an example of a control processing procedure (part 4) in an ultrasonic wind speed meter. [Figure 9] A flowchart showing an example of a control processing procedure (part 5) in an ultrasonic wind speed meter. [Figure 10] A diagram showing an example of a vector indicating wind speed V, the X-axis component, and the Y-axis component of wind speed V. [Figure 11] A graph illustrating the waveforms of signals corresponding to the first observation wave and the second observation wave in Fig. 11(a), and a graph illustrating the waveforms of signals corresponding to the third observation wave and the fourth observation wave in Fig. 11(b). [Figure 12] A graph illustrating the waveforms of signals corresponding to the first observation wave and the second observation wave respectively. [Figure 13] A flowchart showing an example of combining the control processing procedure (part 3) and the control processing procedure (part 4) in an ultrasonic wind speed meter. [Figure 14] A flowchart showing an example of combining the control processing procedure (part 4) and the control processing procedure (part 5) in an ultrasonic wind speed meter.

Embodiments for Carrying Out the Invention

[0010] The ultrasonic anemometer according to the embodiment will be described below with reference to the attached drawings. In this specification and drawings, substantially identical components may be denoted by the same reference numerals to avoid redundant explanations. In this specification, the terms "upper" and "lower" may be used. These refer to the state shown in Figure 1, where the side with the top plate 11 is located in the Z-axis direction is called the "upper" and the side with the reflector 21 is called the "lower". The actual arrangement of the ultrasonic anemometer 100 is not limited to this.

[0011] [Ultrasonic anemometer 100 according to the embodiment] Figure 1 is a schematic cross-sectional view illustrating an ultrasonic anemometer 100 according to an embodiment. Figure 2 is a schematic diagram showing an example of the arrangement of a plurality of ultrasonic transceivers 30 and the vectors Vx, Vy, Va, Vb, Vc, Vd between these plurality of ultrasonic transceivers 30. Note that in each figure, mutually orthogonal X-axis, Y-axis, and Z-axis directions may be shown. The X-axis, Y-axis, and Z-axis directions do not have to be orthogonal. The X-axis, Y-axis, and Z-axis directions may be any direction.

[0012] The ultrasonic anemometer 100 shown in Figure 1 is a wind direction and wind speed measuring device that measures the wind direction and wind speed of a fluid under test based on the propagation time of ultrasonic waves transmitted and received between an ultrasonic transmitter and an ultrasonic receiver. The ultrasonic anemometer 100 can determine wind speed from fluctuations in the speed of sound in the air (approximately 340 m / s). The distance between the ultrasonic transmitter and the ultrasonic receiver is known, and the wind direction and wind speed of the fluid can be measured based on the difference in ultrasonic wave propagation time. Note that "transmission of ultrasonic waves" and "oscillation of ultrasonic transceivers" have the same meaning.

[0013] The ultrasonic anemometer 100 comprises a first housing 10 and a second housing 20. The first housing 10 and the second housing 20 are positioned apart in the Z-axis direction. Multiple support columns extending in the Z-axis direction are provided between the first housing 10 and the second housing 20. The multiple support columns support the first housing 10 relative to the second housing 20. The lower ends of the support columns are fixed to the second housing 20, and the upper ends of the support columns are fixed to the first housing 10. The first housing 10 is equipped with multiple ultrasonic transceivers 30 and a circuit board.

[0014] The ultrasonic anemometer 100 comprises a top plate 11, a plurality of ultrasonic transceivers 30, and a reflector 21.

[0015] [Top plate 11] The top plate 11 is provided on the first housing 10. The top plate 11 is located at the bottom of the first housing 10. The top plate 11 is, for example, disc-shaped. The top plate 11 is provided with a holding section for holding a plurality of ultrasonic transceivers 30.

[0016] [1st plane 12] The top plate 11 has a first plane 12. The first plane 12 is a plane that aligns with the X-axis and Y-axis directions. The first plane 12 is the bottom surface of the top plate 11.

[0017] [Multiple ultrasonic transceivers 30] As shown in Figure 2, the multiple ultrasonic transceivers 30 include a first ultrasonic transceiver 31, a second ultrasonic transceiver 32, a third ultrasonic transceiver 33, and a fourth ultrasonic transceiver 34. The multiple ultrasonic transceivers 30 are mounted on the top plate 11. Each ultrasonic transceiver 30 is an ultrasonic transmitting unit (ultrasonic oscillator) that transmits ultrasonic waves and an ultrasonic receiving unit (ultrasonic receiver) that receives ultrasonic waves. The arrangement of the multiple ultrasonic transceivers 30 will be described later.

[0018] The ultrasonic anemometer 100 may include an ultrasonic oscillator that emits ultrasonic waves and an ultrasonic receiver that receives ultrasonic waves emitted from the ultrasonic oscillator. The ultrasonic anemometer 100 may include one ultrasonic oscillator and one ultrasonic receiver. The ultrasonic anemometer 100 may include multiple ultrasonic oscillators and multiple ultrasonic receivers.

[0019] [Reflector 21] The reflector 21 shown in Figure 1 is provided on the upper part of the second housing 20. The reflector 21 is positioned opposite the top plate 11 in the Z-axis direction. A flow path 101, which is a space through which the fluid to be measured can pass, is formed between the top plate 11 and the reflector 21. The fluid to be measured may be, for example, air. The reflector 21 has a surface that reflects ultrasonic waves transmitted from the ultrasonic transceiver 30.

[0020] [2nd plane 22] The reflector 21 has a second plane 22. The second plane 22 may be the upper surface of the reflector 21. The second plane 22 is a plane that faces the first plane 12 in the Z-axis direction and is parallel to the second plane 22. The second plane 22 is a plane that aligns with the X-axis direction and the Y-axis direction. The second plane 22 may be partially formed on the upper surface of the reflector 21 or may be formed over the entire surface. For example, the second plane 22 is formed in the central part of the upper surface of the reflector 21.

[0021] [Height H] As shown in Figure 2, the height between the first plane 12 and the second plane 22 in the Z-axis direction is height H.

[0022] [Placement of ultrasonic transceiver 30] Next, with reference to Figure 2, the arrangement of the ultrasonic transceivers 30 will be described. The first ultrasonic transceiver 31 and the second ultrasonic transceiver 32 are positioned apart in the X-axis direction. The third ultrasonic transceiver 33 and the fourth ultrasonic transceiver 34 are positioned apart in the Y-axis direction. The first ultrasonic transceiver 31, the second ultrasonic transceiver 32, the third ultrasonic transceiver 33, and the fourth ultrasonic transceiver 34 are positioned in the Z-axis direction, corresponding to the vertices of a virtual square.

[0023] [Ultrasound transmission and reception path] Next, the transmission and reception paths for ultrasonic waves in the ultrasonic anemometer 100 will be described. The ultrasonic anemometer 100 provides diagonal transmission and reception paths UTx and UTy, and adjacent transmission and reception paths UTa, UTb, UTc, and UTd. The diagonal transmission and reception path UTx is the transmission and reception path between the first ultrasonic transceiver 31 and the second ultrasonic transceiver 32. Viewed in the Z-axis direction, the diagonal transmission and reception path UTx is formed to align with the X-axis direction. The diagonal transmission and reception path UTy is the transmission and reception path between the third ultrasonic transceiver 33 and the fourth ultrasonic transceiver 34. Viewed in the Z-axis direction, the diagonal transmission and reception path UTy is formed to align with the Y-axis direction.

[0024] The adjacent transmission / reception path UTa is the transmission / reception path between the second ultrasonic transceiver 32 and the third ultrasonic transceiver 33. The adjacent transmission / reception path UTb is the transmission / reception path between the second ultrasonic transceiver 32 and the fourth ultrasonic transceiver 34. The adjacent transmission / reception path UTc is the transmission / reception path between the first ultrasonic transceiver 31 and the fourth ultrasonic transceiver 34. The adjacent transmission / reception path UTd is the transmission / reception path between the first ultrasonic transceiver 31 and the third ultrasonic transceiver 33.

[0025] The ultrasonic anemometer 100 can directly acquire vectors Vx and Vy located on diagonal transmission and reception paths UTx and UTy. This allows the ultrasonic anemometer 100 to detect wind direction and wind speed with high accuracy. Vector Vx is aligned along the X-axis between the first ultrasonic transceiver 31 and the second ultrasonic transceiver 32. Vector Vy is aligned along the Y-axis between the third ultrasonic transceiver 33 and the fourth ultrasonic transceiver 34.

[0026] The ultrasonic anemometer 100 can acquire vectors Va, Vb, Vc, and Vd located on adjacent transmission / reception paths UTa, UTb, UTc, and UTd. The ultrasonic anemometer 100 can calculate vectors Vx and Vy from vectors Va, Vb, Vc, and Vd.

[0027] [Measurement unit 200] Next, the measurement unit 200 will be described. Figure 3 is a block diagram illustrating the hardware configuration of the ultrasonic anemometer 100 according to the embodiment. The ultrasonic anemometer 100 includes a measurement unit 200. The measurement unit 200 calculates the wind speed V in the flow path 101 based on the data received from the ultrasonic transceiver 30. The measurement unit 200 can also calculate the wind direction. The measurement unit 200 may further have a function to display the calculation results such as the wind speed V. The measurement unit 200 may also output the calculation results such as the wind speed V to an external information processing device.

[0028] The measurement unit 200 includes a control circuit 210, a signal generation circuit 221, and a detection circuit 222. The ultrasonic anemometer 100 may also include a temperature sensor 231. The measurement unit 200 is electrically connected to a plurality of ultrasonic transceivers 30 and a temperature sensor 231. The measurement unit 200 may be a computer including the control circuit 210, signal generation circuit 221, detection circuit 222, and AD converter 223. The measurement unit 200 may calculate the X-axis component Vx of the wind speed V using data acquired from the first ultrasonic transceiver 31 and the second ultrasonic transceiver 32. The measurement unit 200 may calculate the Y-axis component Vy of the wind speed V using data acquired from the third ultrasonic transceiver 33 and the fourth ultrasonic transceiver 34.

[0029] [X-axis and Y-axis components of wind speed V] FIG. 10 is a diagram showing an example of a vector indicating wind speed V, the X-axis component of wind speed V, and the Y-axis component. In the diagonal transmission / reception path, as shown in FIG. 10, in the ultrasonic wind speed meter 100, the wind speed V and the wind direction are calculated using vectors Vx and Vy. In the adjacent transmission / reception path, for example, the X-axis component vector Vx is calculated from vectors Va to Vd. For example, Vx = {(Vc) 2 +(Vd) 2} 1 / 2 ×COSθ cd , or Vx = {(Va) 2 +(Vb) 2} 1 / 2 ×COSθ ab is obtained as follows. Similarly, the Y-axis component vector Vy is calculated from vectors Va to Vd. Here, θ cd =tan -1 (Vc / Vd)-π / 4, and θ ab =tan -1 (Va / Vb)-π / 4. For example, Vy = {(Vd) 2 +(Va) 2} 1 / 2 ×COSθ da , or Vy = {(Vb) 2 +(Vc) 2} 1 / 2 ×COSθ bc is obtained as follows. Here, θ da =tan -1 (Vd / Va)-π / 4, and θ bc =tan -1 (Vb / Vc)-π / 4. Then, in the same manner as in FIG. 10, the wind speed V and the wind direction are calculated from vectors Vx and Vy.

[0030] [Reflected wave] For example, in the diagonal transmission / reception path UTx, the first reflected wave is transmitted from the first ultrasonic transmitter / receiver 31, reflected at a point on the second plane 22, and received by the second ultrasonic transmitter / receiver 32.

[0031] [First ultrasonic wave (from the first ultrasonic transmitter / receiver 31 to the second ultrasonic transmitter / receiver 32)] The ultrasonic waves transmitted from the first ultrasonic transceiver 31 shown in Figure 2 and received by the second ultrasonic transceiver 32 are referred to as "first ultrasonic wave 31x". The first ultrasonic wave 31x is reflected by the second plane 22 and received by the second ultrasonic transceiver 32. During wind speed measurement, the first ultrasonic wave 31x received by the second ultrasonic transceiver 32 is referred to as "first observed wave 31xr".

[0032] [Second ultrasonic (Second ultrasonic transceiver 32 → First ultrasonic transceiver 31)] The ultrasonic waves transmitted from the second ultrasonic transceiver 32 and received by the first ultrasonic transceiver 31 are referred to as "second ultrasonic wave 32x". The second ultrasonic wave 32x is reflected by the second plane 22 and received by the first ultrasonic transceiver 31. During wind speed measurement, the second ultrasonic wave 32x received by the first ultrasonic transceiver 31 is referred to as "second observed wave 32xr".

[0033] [Third Ultrasound (First Ultrasound Transmitter / Receiver 31 → Third Ultrasound Transmitter / Receiver 33)] The ultrasonic waves transmitted from the first ultrasonic transceiver 31 and received by the third ultrasonic transceiver 33 are referred to as "third ultrasonic wave 31d". The third ultrasonic wave 31d is reflected by the second plane 22 and received by the third ultrasonic transceiver 33. During wind speed measurement, the third ultrasonic wave 31d received by the third ultrasonic transceiver 33 is referred to as "third observed wave 31dr".

[0034] [Fourth ultrasonic wave (Third ultrasonic wave transceiver 33 → First ultrasonic wave transceiver 31)] The ultrasonic waves transmitted from the third ultrasonic transceiver 33 and received by the first ultrasonic transceiver 31 are referred to as the "fourth ultrasonic wave 33d". The fourth ultrasonic wave 33d is reflected by the second plane 22 and received by the first ultrasonic transceiver 31. During wind speed measurement, the fourth ultrasonic wave 33d received by the first ultrasonic transceiver 31 is referred to as the "fourth observed wave 33dr".

[0035] Figure 11(a) is a graph illustrating the waveforms of the signals corresponding to the first and second observed waves, respectively, and Figure 11(b) is a graph illustrating the waveforms of the signals corresponding to the third and fourth observed waves, respectively.

[0036] The horizontal axis of Figure 11(a) shows the elapsed time from the start of transmission of the first observation wave 31xr or the second observation wave 32xr. However, the origin of the horizontal axis of the figure corresponds to a predetermined time after the start of transmission of the first observation wave 31xr or the second observation wave 32xr. The vertical axis of Figure 11(a) shows the amplitude of the first signal 31Sx corresponding to the first observation wave 31xr and the second signal 32Sx corresponding to the second observation wave 32xr, respectively.

[0037] The horizontal axis of Figure 11(b) shows the elapsed time from the start of transmission of the third observation wave 31dr or the fourth observation wave 33dr. However, the origin of the horizontal axis of the figure corresponds to a predetermined time after the start of transmission of the third observation wave 31dr or the fourth observation wave 33dr. The vertical axis of Figure 11(b) shows the amplitudes of the third signal 31Sd corresponding to the third observation wave 31dr and the fourth signal 33Sd corresponding to the fourth observation wave 33dr.

[0038] The control circuit 210 calculates the first wind speed Vx using the first time t31xa, when the first ultrasonic transceiver 31 transmits the first ultrasonic wave 31x and the second ultrasonic transceiver 32 receives the first ultrasonic wave 31x, and the second time t32xa, when the second ultrasonic transceiver 32 transmits the second ultrasonic wave 32x and the first ultrasonic transceiver 31 receives the second ultrasonic wave 32x. Here, the first time t31xa and the second time t32xa are the points where the amplitude becomes zero, and these points are called zero-crossing points. The first time t31xa and the second time t32xa are also called propagation times.

[0039] The control circuit 210 can calculate the second wind speed Vd using the third time t31da, when the first ultrasonic transceiver 31 transmits the third ultrasonic wave 31d and the third ultrasonic transceiver 33 receives the third ultrasonic wave 31d, and the fourth time t33da, when the third ultrasonic transceiver 33 transmits the fourth ultrasonic wave 33d and the first ultrasonic transceiver 31 receives the fourth ultrasonic wave 33d.

[0040] The control circuit 210 calculates the first wind speed Vy using the first time t33ya, when the third ultrasonic transceiver 33 transmits the first ultrasonic wave 33y and the fourth ultrasonic transceiver 34 receives the first ultrasonic wave 33y, and the second time t34ya, when the fourth ultrasonic transceiver 34 transmits the second ultrasonic wave 34y and the third ultrasonic transceiver 33 receives the second ultrasonic wave 34y.

[0041] The control circuit 210 calculates the second wind speed Vc using the third time t31ca, when the first ultrasonic transceiver 31 transmits the third ultrasonic wave 31c and the fourth ultrasonic transceiver 34 receives the third ultrasonic wave 31c, and the fourth time t34ca, when the fourth ultrasonic transceiver 34 transmits the fourth ultrasonic wave 33c and the first ultrasonic transceiver 31 receives the fourth ultrasonic wave 33c.

[0042] The control circuit 210 can calculate the second wind speed Va using the third time t32aa, when the second ultrasonic transceiver 32 transmits the third ultrasonic wave 32a and the third ultrasonic transceiver 33 receives the third ultrasonic wave 32a, and the fourth time t33aa, when the third ultrasonic transceiver 33 transmits the fourth ultrasonic wave 33a and the second ultrasonic transceiver 32 receives the fourth ultrasonic wave 33a.

[0043] The control circuit 210 can calculate the second wind speed Vb using the third time t32ba, when the second ultrasonic transceiver 32 transmits the third ultrasonic wave 32b and the fourth ultrasonic transceiver 34 receives the third ultrasonic wave 32b, and the fourth time t34ba, when the fourth ultrasonic transceiver 34 transmits the fourth ultrasonic wave 34b and the second ultrasonic transceiver 32 receives the fourth ultrasonic wave 34b.

[0044] The control circuit 210 defines the time closest to the fifth time t5 among the times when the amplitude of the second ultrasonic transceiver 32 receives the first ultrasonic wave 31x as the first time t31xa. The control circuit 210 defines the time closest to the fifth time t5 among the times when the amplitude of the first ultrasonic transceiver 31 receives the second ultrasonic wave 32x as the second time t32xa. The control circuit 210 calculates the first wind speed Vx using the first time t31xa and the second time t32xa.

[0045] The control circuit 210 defines the time closest to the fifth time t5 among the times when the amplitude becomes zero when the third ultrasonic transceiver 33 receives the third ultrasonic wave 31d as the third time t31da. The control circuit 210 defines the time closest to the fifth time t5 among the times when the amplitude becomes zero when the first ultrasonic transceiver 31 receives the fourth ultrasonic wave 33d as the fourth time t33da, and calculates the second wind speed Vd.

[0046] The control circuit 210 defines the time closest to the fifth time t5 among the times when the amplitude becomes zero when the fourth ultrasonic transceiver 34 receives the first ultrasonic wave 33y as the first time t33ya. The control circuit 210 defines the time closest to the fifth time t5 among the times when the amplitude becomes zero when the third ultrasonic transceiver 33 receives the second ultrasonic wave 34y as the second time t34ya. The control circuit 210 calculates the first wind speed Vy using the first time t33ya and the second time t34ya.

[0047] The control circuit 210 sets the time closest to the fifth time t5 among the times when the amplitude becomes zero when the fourth ultrasonic transceiver 34 receives the third ultrasonic wave 31c as the third time t31ca. The control circuit 210 sets the time closest to the fifth time t5 among the times when the amplitude becomes zero when the first ultrasonic transceiver 31 receives the fourth ultrasonic wave 34c as the fourth time t34ca, and calculates the second wind speed Vc.

[0048] The control circuit 210 defines the time closest to the fifth time t5 among the times when the amplitude of the third ultrasonic transceiver 33 is zero when it receives the third ultrasonic wave 32a as the third time t32aa. The control circuit 210 defines the time closest to the fifth time t5 among the times when the amplitude of the second ultrasonic transceiver 32 is zero when it receives the fourth ultrasonic wave 33a as the fourth time t33aa, and calculates the second wind speed Va.

[0049] The control circuit 210 defines the time closest to the fifth time t5 among the times when the amplitude of the fourth ultrasonic transceiver 34 receives the third ultrasonic wave 32b as the third time t32ba. The control circuit 210 defines the time closest to the fifth time t5 among the times when the amplitude of the second ultrasonic transceiver 32 receives the fourth ultrasonic wave 34b as the fourth time t34ba, and calculates the second wind speed Vb.

[0050] [Principle for calculating wind speed V] The propagation time T31x of the first observed wave 31xr and the propagation time T32x of the second observed wave 32xr are expressed by equations (3) and (4), respectively, using the distance A1, the speed of sound C1, and the wind speed V.

[0051] T31x = A1 / (C1 + V) ... (1) T32x = A1 / (C1 - V) ... (2)

[0052] Furthermore, equation (3) relating to wind speed V can be obtained from [equation (1) - equation (2)].

[0053] V=(A1 / 2)[(1 / T31x)-(1 / T32x)] ···(3)

[0054] [Regarding ToF shifts] Next, an example of ToF shift that occurs when calculating wind speed V will be explained with reference to Figure 12. Figure 12 is a graph illustrating the waveforms of signals corresponding to the first and second observed waves, respectively. The horizontal axis of Figure 12 shows the elapsed time from the start of transmission of the first observed wave 31xr or the second observed wave 32xr. However, the origin of the horizontal axis of the figure corresponds to a point in time after a predetermined time has elapsed from the start of transmission of the first observed wave 31xr or the second observed wave 32xr. The vertical axis of Figure 12 shows the amplitudes of the first signal 31Sx corresponding to the first observed wave 31xr and the second signal 32Sx corresponding to the second observed wave 32xr, respectively. Figure 12(a) shows the waveforms of the first signal 31Sx and the second signal 32Sx when the wind speed V in the flow path 101 is Vxa [m / s]. Note that Vxa is a non-zero value. Figure 12(b) shows the waveforms of the first signal 31Sx and the second signal 32Sx when the wind speed V in the flow path 101 is Vxb [m / s], which is greater than Vxa.

[0055] In the comparative example, with respect to propagation time T31x, for example, the time when the peak value of the first signal 31Sx becomes zero (time t31xa in Figure 12(a)) is detected, and with respect to propagation time T32x, for example, the time when the peak value of the second signal 32Sx becomes zero (time t32xa in Figure 12(a)) is detected. Time t31xa is defined as the time that belongs to the nth period of the first signal 31Sx. Time t32xa is defined as the time that belongs to the nth period of the second signal 32Sx. That is, time t31xa and time t32xa are time points identified by the same peak value that belongs to the same numbered period for each signal related to the first signal 31Sx and the second signal 32Sx. Note that with respect to propagation time T1, a time when the peak value of the first signal 31Sx is a value other than zero may be detected. With respect to propagation time T32x, a time when the peak value of the second signal 32Sx is a value other than zero may be detected.

[0056] As shown in Figure 12(a), if the difference between the phase of the first signal 31Sx corresponding to time t31xa and the phase of the second signal 32Sx corresponding to time t32xa is less than or equal to the value of one period of the first signal 31Sx or the second signal 32Sx (for example, 2π), then the time points in which the signals related to the first signal 31Sx and the second signal 32Sx have the same peak value belonging to the same numbered period will be chronologically close. Therefore, the time points in which the signals related to the first signal 31Sx and the second signal 32Sx have the same peak value belonging to the same numbered period will be appropriately detected.

[0057] In contrast, as the wind speed V increases, as shown in Figure 12(b), the difference between the phase corresponding to time t31xa of the first signal 31Sx and the phase corresponding to time t32xa of the second signal 32Sx exceeds the value of one period of either the first signal 31Sx or the second signal 32Sx. In this case, the time points in the first signal 31Sx and the second signal 32Sx that have the same wave height value and belong to the same period number become further apart in the time series. Therefore, for example, in the second signal 32Sx, it is possible to detect time t32xb, which belongs to the (n-1)th period and is close to time t31xa of the first signal 31Sx. The same applies to the first signal 31Sx. That is, time points in the first signal 31Sx and the second signal 32Sx that have the same wave height value and belong to different period numbers may be detected, and the wind speed V may be measured incorrectly. Hereafter, this phenomenon will be referred to as the "ToF shift".

[0058] Here, if the starting points of the first signal 31Sx and the second signal 32Sx are aligned, the nth period can be correctly determined. However, because the vibrations generated when the ultrasonic transceiver emits ultrasound are transmitted through the first housing 10 to the other ultrasonic transceiver, the starting point of the first signal 31Sx cannot be determined. This phenomenon is called housing propagation. Similarly, the starting point of the second signal 32Sx cannot be determined due to housing propagation. This phenomenon becomes particularly noticeable when the distance between ultrasonic transceivers is shortened for miniaturization. Therefore, the point in time after a predetermined amount of time has elapsed since the transceiver started transmitting ultrasound is taken as the nth period of the first signal 31Sx, and the period of the second signal 32Sy that is close to time t31xa is judged to belong to the nth period.

[0059] [Signal generation circuit 221] The signal generation circuit 221 generates an AC signal that will be used as the basis for the ultrasonic wave used as the measurement wave, and outputs the generated AC signal to the first ultrasonic transceiver 31. The signal generation circuit 221 also generates an AC signal that will be used as the basis for the ultrasonic wave used as the measurement wave, and outputs the generated AC signal to the second ultrasonic transceiver 32. An example of an AC signal generated by the signal generation circuit 221 is an analog electrical signal corresponding to a sine wave having a predetermined period and amplitude. Preferably, the sine wave corresponding to the AC signal to the first ultrasonic transceiver 31 and the sine wave corresponding to the AC signal to the second ultrasonic transceiver 32 have approximately the same period (frequency).

[0060] An example of a signal generation circuit 221 is a circuit that includes an oscillator circuit containing a crystal oscillator, a digital-to-analog converter (DA converter) that converts a digital signal such as a pulse signal oscillated from the oscillator circuit into an analog AC signal, and a switching circuit that switches the transceiver to which the AC signal is output according to a selection signal input from the control circuit 210. However, the configuration of the signal generation circuit 221 is not limited to this.

[0061] [Detection circuit 222] The detection circuit 222 detects the signal related to the measurement wave received by the first ultrasonic transceiver 31. The detection circuit 222 also detects the signal related to the measurement wave received by the second ultrasonic transceiver 32.

[0062] The detection circuit 222 outputs the first signal and the second signal related to the detected measurement wave to the AD converter 223. The AD converter 223 converts the analog signal received from the detection circuit 222 into a digital signal and outputs it to the control circuit 210.

[0063] An example of a detection circuit 222 is a circuit that includes a switching circuit that switches the output signal to the control circuit 210 based on a first signal and a second signal, an amplification circuit that amplifies the first signal or the second signal output through the switching circuit, and an analog-to-digital converter that converts the analog AC signal of the amplified first signal or the second signal into a digital signal. However, the configuration of the detection circuit 220 is not limited to this.

[0064] [Temperature sensor 231] The temperature sensor 231 may, for example, detect the temperature inside the flow path 101 when measuring wind speed. The temperature sensor 231 outputs information about the detected temperature to the control circuit 210. The information about the temperature detected by the temperature sensor 231 may be stored in the memory unit 212 of the control circuit 210. The information about the temperature detected by the temperature sensor 231 can be used, for example, when calculating the speed of sound C1.

[0065] The temperature sensor 231 can be any device capable of detecting the temperature in the flow path 101. Examples of temperature sensors 231 include thermistors, linear resistors, platinum resistance thermometers, thermocouples, and thermopile.

[0066] [Control circuit 210] The control circuit 210 includes, for example, a CPU (Central Processing Unit) 211 and a storage unit 212. The storage unit 212 includes a ROM (Read Only Memory) 213 and a RAM (Random Access Memory). The CPU 211 performs various processes according to a program stored in the storage unit 212. The program, when executed by the CPU 211, enables the measurement unit 200 to function as a means for measuring wind speed V, etc. The program may be stored on an external storage medium such as a hard disk or flash memory. Alternatively, the program may be transmitted to the control circuit 210 via a communication line. The transmitted program is installed in the storage unit 212 of the control circuit 210. The storage unit 212 stores various information necessary for calculating wind speed V. The storage unit 212 stores information regarding the height H between the first plane 12 and the second plane 22, as well as information regarding the distance between the multiple ultrasonic transceivers 30.

[0067] [Calculation of variance] The control circuit 210 can use the ultrasonic signals received by the ultrasonic transceiver 30 as received data and calculate the variance of this received data. Here, an example of received data is propagation time. Variance is the average of the squares of the deviations from the arithmetic mean. The control circuit 210 can perform AD conversion on the received waveform when the ultrasonic transceiver 30 is not emitting ultrasonic pulses, and use this AD-converted data as received data. The control circuit 210 can calculate the variance from data based on the received waveform received over a certain period (data after AD conversion).

[0068] The control circuit 210 can determine whether the calculated wind speed value is normal or not by using the calculated variance value as a judgment threshold (first judgment threshold). The control circuit 210 can turn ON a flag indicating that the variance value exceeds the judgment threshold if the variance value exceeds the judgment threshold. The control circuit 210 can turn OFF the flag if the variance value is less than or equal to the judgment threshold. This "flag being ON" can also be described as "the switch being ON". This "flag being OFF" can also be described as "the switch being OFF".

[0069] The control circuit 210 can determine that the original data for the calculated wind speed is erroneous if the switch is OFF when the calculated wind speed corresponds to a high wind speed.

[0070] For example, the control unit may mismeasure the wind speed as high if raindrops adhere to the ultrasonic transceiver 30. If the actual wind speed does not correspond to a high wind speed, the control circuit 210 can determine that the measurement is incorrect because the switch is OFF.

[0071] [Relationship between set wind speed and dispersion] Wind tunnel experiments were conducted to verify the effectiveness of the present invention. Figure 4 is a graph showing an example of the relationship between the set wind speed and the variance value. In Figure 4, the horizontal axis shows the set wind speed [m / s] and the vertical axis shows the variance value. The "set wind speed" is the wind speed generated in the wind tunnel experiment. Here, the propagation time at the zero-crossing point was obtained assuming that ultrasound was transmitted without generating ultrasound. In addition, the wind tunnel experiment was conducted with no water droplets attached to the first plane 12, the second plane 22 of the ultrasonic anemometer 100, and the ultrasonic transceiver 30. Here, when the wind speed exceeded the predetermined value "A" (30 m / s) in the figure, the variance value of the received data increased significantly. That is, the variability of the variance value of the received data increased due to the vibration of the ultrasonic receiver itself caused by the strong wind. "High wind speed" and "low wind speed" are defined with this predetermined value as the boundary. For example, a set wind speed of 30 m / s or more may be defined as "high wind speed". For example, a set wind speed of less than 30 m / s may be defined as "low wind speed". As described above, the variance value is calculated from data based on the received waveform (data after AD conversion) received by the ultrasonic transceiver 30 when the ultrasonic transceiver 30 on the transmitting side is not emitting ultrasonic pulses.

[0072] The control circuit 210 can use the variance value when the set wind speed is 30 m / s as the first judgment threshold to determine whether the calculated wind speed is an error in measurement.

[0073] [Control Processing Procedure for Ultrasonic Anemometers (Part 1)] Next, the first part of the control processing procedure in the ultrasonic anemometer 100 will be explained. Figure 5 is a flowchart showing an example of the first part of the control processing procedure in the ultrasonic anemometer. First, the measurement unit 200 acquires first received data from the ultrasonic transceiver 30 (step S11). The "first received data" is data received by the receiving ultrasonic transceiver 30 when the transmitting ultrasonic transceiver 30 is not emitting ultrasound. Specifically, the waveform for a predetermined time is converted by the AD converter 223, and the wavelength is used as the distance between zero-crossing points detected at the predetermined time, and the dispersion of this wavelength is output. Alternatively, the waveform for a predetermined time may be converted by the AD converter 223 and the dispersion of the amplitude detected at the predetermined time may be output. Detecting the amplitude is simpler to process than detecting the distance between zero-crossing points, thus improving the processing speed.

[0074] Next, the measurement unit 200 causes the transmitting ultrasonic transceiver 30 to transmit ultrasonic waves (step S12). The transmitting ultrasonic transceiver 30 emits ultrasonic waves. The receiving ultrasonic transceiver 30 receives the ultrasonic waves emitted from the transmitting ultrasonic transceiver 30.

[0075] Next, the measurement unit 200 acquires second received data from the receiving ultrasonic transceiver 30 (step S13). The "second received data" is the data received by the receiving ultrasonic transceiver 30 from the ultrasonic waves emitted by the receiving ultrasonic transceiver 30. Specifically, it is the time (propagation time) at the zero-crossing point closest to a predetermined time after the ultrasonic transceiver 30 has emitted waves. Here, the predetermined times for the "first received data" and the "second received data" can be the same. Alternatively, the ultrasonic waveform received by the ultrasonic transceiver may be converted by the AD converter 223 to find the zero-crossing point and output the first received data.

[0076] Next, perform steps S11 to S13 by changing the transmitting and receiving sensors (step S15). For example, in steps 11 to 13, the oscillator that transmits ultrasound is the ultrasonic transceiver 30(31) in Figure 2, and the receiver that receives ultrasound is the ultrasonic transceiver 30(32). In this case, in step 15, change the oscillator that transmits ultrasound to the ultrasonic transceiver 30(32) and the receiver that receives ultrasound to the ultrasonic transceiver 30(31). Note that the change of the transmitting and receiving sensors in step 15 may be performed multiple times. For example, in step 15, change the oscillator that transmits ultrasound to the ultrasonic transceiver 30(32) and the receiver that receives ultrasound to the ultrasonic transceiver 30(31). After that, change the oscillator that transmits ultrasound to the ultrasonic transceiver 30(33) and the receiver that receives ultrasound to the ultrasonic transceiver 30(34), and perform steps S11 to S13.

[0077] Next, the measurement unit 200 determines whether a predetermined time has elapsed (step S16). Here, the predetermined time is the time required to acquire a sufficient amount of data from the first and second received data so that distributed calculation becomes possible. The predetermined time is, for example, 3 seconds.

[0078] In step S17, the measurement unit 200 calculates the variance of the first received data and the second received data.

[0079] In the ultrasonic anemometer 100, data may be acquired for 3 seconds in all directions for steps S11 to S13 and steps S15 to S17. Here, "all directions" means receiving data from all sensors 1 to 4. For example, sensor 1 may be ultrasonic transceiver 31, sensor 2 may be ultrasonic transceiver 32, sensor 3 may be ultrasonic transceiver 33, and sensor 4 may be ultrasonic transceiver 34. Although steps S11 to S17 show the case with two ultrasonic transceivers, steps 11 to 18 can be repeated for all ultrasonic transceivers 31 to 34.

[0080] [Control Processing Procedure for Ultrasonic Anemometers (Part 2)] Next, the control processing procedure (part 2) in the ultrasonic anemometer 100 will be described. Figure 6 is a flowchart showing an example of the control processing procedure (part 2) in the ultrasonic anemometer. In the ultrasonic anemometer 100, the flow shown in Figure 5 is executed, followed by the flow shown in Figure 6.

[0081] Next, the measurement unit 200 calculates the average value of the variance for each ultrasonic transceiver 30 over a predetermined period (step S21). The measurement unit 200 calculates the average value of the variance for all ultrasonic transceivers 30. In the example in Figure 6, there are two ultrasonic transceivers, but if there are four ultrasonic transceivers, the average value of the variance for the four ultrasonic transceivers is calculated.

[0082] Next, the control circuit 210 determines whether or not it has calculated the average value of the variance for all ultrasonic transceivers 30 (step S22). If the control circuit 210 has not calculated the average value of the variance for all ultrasonic transceivers 30 (step S22; NO), it repeats the process in step S22. If the control circuit 210 has calculated the average value of the variance for all ultrasonic transceivers 30 (step S22; YES), it terminates the process at this point.

[0083] [Control Processing Procedure for Ultrasonic Anemometers (Part 3)] Next, the control processing procedure (part 3) in the ultrasonic anemometer 100 will be described. Figure 7 is a flowchart showing an example of the control processing procedure (part 3) in the ultrasonic anemometer. In the ultrasonic anemometer 100, the flow shown in Figure 6 is executed, followed by the flow shown in Figure 7.

[0084] First, the control circuit 210 determines whether the average value of the variance exceeds the first judgment threshold (step S31). If the average value of the variance exceeds the first judgment threshold (step S31; YES), the control circuit 210 executes the process in step S32. If the average value of the variance is less than or equal to the first judgment threshold (step S31; NO), the control circuit 210 executes the process in step S37.

[0085] In step S32, the control circuit 210 turns on a switch. Here, it turns on a switch that indicates that the average value of the variance exceeds the first judgment threshold.

[0086] Next, the control circuit 210 calculates the wind speed value from the second received data (step S33). In step S33, the wind speed is calculated from the second received data acquired in step S13. Specifically, the wind speed is calculated using the method described in Figure 10.

[0087] Next, the control circuit 210 determines whether the wind speed value exceeds the first reference value (step S34). The first reference value may be, for example, 30 m / s. The first judgment threshold for the dispersion value is the value corresponding to the first reference value for wind speed. An example of the dispersion value which is the first judgment threshold is shown by a dashed line in Figure 4. If the wind speed value calculated in step S33 exceeds the first reference value (step S34; YES), the control circuit 210 executes the process in step S35. If the wind speed value is less than or equal to the first reference value (step S34; NO), the control circuit 210 executes the process in step S36.

[0088] In step S35, the control circuit 210 determines that the wind speed calculated in step S33 is "normal". In step S36, the control circuit 210 determines that the wind speed calculated in step S33 is "abnormal". After the completion of step S35 or step S36, the control circuit 210 terminates the processing at this point.

[0089] In step S37, the control circuit 210 turns off a switch. Here, it turns off the switch that indicates that the average value of the variance exceeds the first judgment threshold.

[0090] Next, the control circuit 210 calculates the wind speed value from the second received data (step S38). In step S38, the wind speed is calculated from the second received data acquired in step S13.

[0091] Next, the control circuit 210 determines whether the wind speed value exceeds the first reference value (step S39). If the wind speed value calculated in step S39 exceeds the first reference value (step S39; YES), the control circuit 210 executes the process in step S40. If the wind speed value is less than or equal to the first reference value (step S39; NO), the control circuit 210 executes the process in step S41.

[0092] In step S40, the control circuit 210 determines that the wind speed calculated in step S38 is "abnormal". In step S41, the control circuit 210 determines that the wind speed calculated in step S38 is "normal". After the completion of step S40 or step S41, the control circuit 210 terminates the processing at this point.

[0093] Here, if an "abnormality" is determined in steps S36 and S40, the measurement unit 200 can be controlled not to output the calculated wind speed value. Alternatively, if an "abnormality" is determined in steps S36 and S40, the measurement unit 200 can be controlled to output an error signal.

[0094] [Control Processing Procedure for Ultrasonic Anemometers (Part 4)] Next, the control processing procedure (part 4) in the ultrasonic anemometer 100 will be described. Figure 8 is a flowchart showing an example of the control processing procedure (part 4) in the ultrasonic anemometer. In the ultrasonic anemometer 100, the flow shown in Figure 6 is executed, followed by the flow shown in Figure 8. In Figure 8, the same steps as in Figure 7 are given the same step numbers. In the explanation of Figure 8, explanations similar to those in Figure 7 may be omitted.

[0095] After executing the processes in steps S31 and S32, the control circuit 210 executes the process in step S51.

[0096] In step S51, the control circuit 210 determines whether the rain protection function is ON or OFF. The "rain protection function" is a function to reduce errors that occur when raindrops adhere to the ultrasonic transmitting surface of the ultrasonic transceiver 30 of the ultrasonic anemometer 100. It can also be described as a function to prevent misjudgment of wind speed when the ultrasonic anemometer 100 is in a specific state. "Rain protection function ON" may also mean that the rain protection function is operating. The "rain protection function" includes "a function to reduce zero-crossing points when amplitude decreases" and "a mechanism to set wind speed to 0". Although zero-crossing points are explained in Figures 11 and 12, in order to improve wind speed accuracy, the propagation time may be calculated from the average time of multiple zero-crossing points near a predetermined time. Here, when the amplitude decreases (the magnitude of the amplitude becomes smaller), it becomes easier to misjudge the zero-crossing point, so the number of zero-crossing points is reduced when calculating the propagation time.

[0097] Here, if raindrops adhere to the surface of the ultrasonic transceiver 30, the measurement unit 200 may incorrectly calculate a high wind speed. However, if the switch is on, a high wind speed condition is observed. In this case, if a high wind speed condition is observed, the raindrops on the surface of the ultrasonic transceiver 30 will be blown away by the wind, so the "rain protection function" is unnecessary. Furthermore, wind tunnel tests have shown that even if raindrops adhere to the surface of the ultrasonic transceiver 30, the dispersion of received data does not increase significantly. In other words, if the switch is on, the "rain protection function" is unnecessary. Moreover, if the "rain protection function" is turned on when there are no raindrops adhering to the surface of the ultrasonic transceiver 30 in a high wind speed condition, the accuracy of the wind speed will decrease due to the "function to reduce zero-crossing points when amplitude decreases" and the "mechanism to set the wind speed to 0".

[0098] The control circuit 210 executes the process in step S52 if the rain protection function is ON (step S51; YES). The control circuit 210 executes the process in step S33 if the rain protection function is OFF (step S51; NO).

[0099] In step S52, the control circuit 210 turns off some of the rain protection functions. The control circuit 210 can turn off some of the multiple rain protection functions. For example, the control circuit 210 can turn off the "function to reduce zero-crossing points when amplitude decreases" and the "mechanism to set wind speed to 0" among the rain protection functions. Note that the "rain protection function" also has a function to prevent false detection of wind speed based on temperature. However, this function does not reduce wind speed accuracy at high wind speeds, so it does not need to be turned off.

[0100] After executing step S52, the control circuit 210 executes the process in step S33.

[0101] After executing the processes in steps S31 and S37, the control circuit 210 executes the process in step S53.

[0102] In step S53, the control circuit 210 turns on the rain protection function. If the rain protection function is ON, the control circuit 210 keeps it ON, and if the rain protection function is OFF, it switches it ON.

[0103] After executing step S53, the control circuit 210 executes step S38.

[0104] [Control Processing Procedure for Ultrasonic Anemometers (Part 5)] Next, the control processing procedure (5) in the ultrasonic anemometer 100 will be explained. Figure 9 is a flowchart showing an example of the control processing procedure (5) in the ultrasonic anemometer. In the ultrasonic anemometer 100, the flow shown in Figure 6 is executed, followed by the flow shown in Figure 9. In Figure 9, the same steps as those shown in Figures 7 and 8 are given the same step numbers. In the explanation of Figure 9, explanations similar to those in Figures 7 and 8 may be omitted. The control circuit 210 can execute the flow shown in Figure 9 instead of the flow shown in Figure 7. The control circuit 210 can use the previous wind speed and wind direction data to determine if a value has changed significantly, which is a ToF shift. For example, when a ToF shift occurs, the wind speed may become more than ten times the wind speed calculated previously, or the wind direction may change by 180 degrees from the wind direction calculated previously. However, if the previously calculated data to be saved is abnormal data, it will be unsuitable as data to be used to determine a ToF shift.

[0105] After executing step S35, the control circuit 210 executes the process in step S61. In step S61, the control circuit 210 saves the wind speed value calculated in step S33 as data for determining Tof shift.

[0106] After executing step S36, the control circuit 210 executes the process in step S62. In step S62, the control circuit 210 does not save the wind speed value calculated in step S33 as data for determining Tof shift.

[0107] After executing step S40, the control circuit 210 executes the process in step S63. In step S63, the control circuit 210 does not save the wind speed value calculated in step S38 as data for determining Tof shift.

[0108] After executing step S41, the control circuit 210 executes the process in step S64. In step S64, the control circuit 210 saves the wind speed value calculated in step S38 as data for determining Tof shift.

[0109] [Effects and Effects of the Ultrasonic Anemometer 100 According to the Embodiment] The ultrasonic anemometer 100 according to this embodiment includes an ultrasonic transceiver (ultrasonic oscillator) 31 that emits ultrasonic waves, an ultrasonic transceiver (ultrasonic receiver) 32 that receives ultrasonic waves emitted from the ultrasonic transceiver 31, and a control circuit 210 that controls the emission of ultrasonic waves by the ultrasonic transceiver 31 and processes data received by the ultrasonic transceiver 32. The control circuit 210 calculates the variance of the first received data received by the ultrasonic transceiver 32 when the ultrasonic transceiver 31 is not emitting ultrasonic waves, and determines that a high wind speed state is occurring when the value obtained by the variance exceeds a first determination threshold, which means the wind speed is higher than a first reference value.

[0110] With such an ultrasonic anemometer 100, it is possible to determine whether or not a high wind speed condition is present based on the dispersion value, thereby suppressing misjudgments. This improves the measurement accuracy of the ultrasonic anemometer 100. Furthermore, the ultrasonic anemometer 100 may implement control to not output the calculated wind speed value if it determines that an "abnormal" condition is present. Alternatively, the ultrasonic anemometer 100 may implement control to output an "error signal" if it determines that an "abnormal" condition is present.

[0111] Furthermore, in the ultrasonic anemometer 100, the control circuit 210 calculates a first wind speed based on the result of the ultrasonic receiver receiving ultrasonic waves emitted by the ultrasonic oscillator when a high wind speed condition is present. If the calculated first wind speed is lower than a first reference value, the control circuit 210 can determine that the calculated first wind speed is an abnormal value.

[0112] Furthermore, in the ultrasonic anemometer 100, the control circuit 210 calculates a second wind speed based on the ultrasonic receiving of ultrasonic waves emitted by the ultrasonic oscillator when the wind speed is not high. If the calculated second wind speed is higher than the first reference value, the control circuit 210 can determine that the calculated second wind speed is an abnormal value.

[0113] Furthermore, in the ultrasonic anemometer 100, the control circuit 210 can perform a first function to prevent misjudgment when a specific condition occurs, such as when raindrops are present on the surface of the ultrasonic transceiver 30. The control circuit 210 can perform a first function to prevent misdetection of wind speed when the ultrasonic transceiver receives ultrasonic waves emitted by the ultrasonic oscillator, but does not perform the first function when the wind speed is high.

[0114] Furthermore, in the ultrasonic anemometer 100, the control circuit 210 is capable of performing a first function to prevent false detection of wind speed when the ultrasonic transceiver receives ultrasonic waves emitted by the ultrasonic oscillator. In the case of high wind speed conditions, the control circuit 210 may determine whether or not to perform the first function based on second received data obtained when the ultrasonic transceiver receives ultrasonic waves emitted by the ultrasonic oscillator, and may perform the first function if the wind speed conditions are not high.

[0115] Furthermore, in the ultrasonic anemometer 100, the control circuit 210 has a second function to prevent false detection of wind speed when the ultrasonic transceiver receives ultrasonic waves emitted by the ultrasonic oscillator, and can perform a second function to prevent false detection of wind speed based on temperature, and can perform the second function when the wind speed is high.

[0116] Furthermore, in the ultrasonic anemometer 100, the control circuit 210 can perform a third function in which, when a high wind speed is detected, it calculates the wind speed and wind direction based on the result of the ultrasonic transceiver receiving the ultrasonic waves emitted by the ultrasonic oscillator, stores the first wind direction data which is the result of the calculation, and in the next measurement of the first wind direction data, when a high wind speed is detected, it calculates the next wind speed and wind direction based on the result of the ultrasonic transceiver receiving the ultrasonic waves emitted by the ultrasonic oscillator, compares the second wind direction data which is the result of the calculation with the first wind direction data, and stores the second wind direction data if the wind direction is in the same direction. However, if the next wind speed which is the result of the calculation is determined to be an abnormal value, the third function does not need to be performed.

[0117] Furthermore, in the ultrasonic anemometer 100, the control circuit 210 performs the steps of receiving first received data with the ultrasonic receiver while the ultrasonic oscillator is not emitting ultrasonic waves, and after receiving the first received data, emitting ultrasonic waves with the ultrasonic oscillator and receiving second received data with the ultrasonic receiver. The control circuit 210 can alternately perform the steps of receiving the first received data and receiving the second received data multiple times.

[0118] Furthermore, in the ultrasonic anemometer 100, the ultrasonic oscillator includes a first ultrasonic oscillator, a second ultrasonic oscillator, and an nth ultrasonic oscillator, and the ultrasonic receiver includes a first ultrasonic receiver, a second ultrasonic receiver, and an nth ultrasonic receiver, where n is a natural number of 3 or more, and the control circuit 210 includes the steps of receiving the first received data with the first ultrasonic receiver when the ultrasonic oscillator is not emitting ultrasonic waves, and after receiving the first received data with the first ultrasonic receiver, emitting ultrasonic waves with the first ultrasonic oscillator and receiving the second received data with the first ultrasonic receiver, and the ultrasonic oscillator The following steps can be performed: receiving first received data with a second ultrasonic receiver in a state where ultrasonic waves are not being emitted; after receiving first received data with the second ultrasonic receiver, emitting ultrasonic waves with the second ultrasonic oscillator and receiving second received data with the second ultrasonic receiver; receiving first received data with the nth ultrasonic receiver in a state where ultrasonic waves are not being emitted with the ultrasonic oscillator; and after receiving first received data with the nth ultrasonic receiver, emitting ultrasonic waves with the nth ultrasonic oscillator and receiving second received data with the nth ultrasonic receiver.

[0119] Furthermore, in the ultrasonic anemometer 100, the control circuit 210 can perform the step of calculating the variance for the first received data after performing the step of receiving the first received data from all ultrasonic receivers. Also, as shown in Figure 13, Figures 7 and 8 can be combined. Also, as shown in Figure 14, Figures 8 and 9 can be combined.

[0120] [program] The program according to the embodiment is a program that causes a computer (CPU 211) to perform a process of measuring wind speed using an ultrasonic anemometer 100, and the program causes the computer to perform the following: a process of calculating the variance of first received data received by an ultrasonic receiver when the ultrasonic oscillator is not emitting ultrasonic waves; a process of determining that the wind speed is higher than a first reference value if the value of the variance exceeds a first judgment threshold; a process of calculating a first wind speed based on the result of the ultrasonic transceiver receiving ultrasonic waves emitted by the ultrasonic oscillator when the wind speed is high; a process of determining that the first wind speed is an abnormal value if the calculated first wind speed is lower than the first reference value; and a process of outputting the calculated first wind speed if the calculated first wind speed is higher than the first reference value.

[0121] Furthermore, other embodiments may be used in which other components are combined with the configurations listed in the above embodiments, and the present invention is not limited in any way to the configurations shown herein. In this regard, modifications can be made without departing from the spirit of the present invention, and can be appropriately determined according to the application form.

[0122] In the above embodiment, an example is given in which the ultrasonic anemometer 100 comprises a first ultrasonic transceiver 31, a second ultrasonic transceiver 32, a third ultrasonic transceiver 33, and a fourth ultrasonic transceiver 34. However, the ultrasonic anemometer 100 may also comprise two or more ultrasonic transceivers 30.

[0123] Furthermore, although the above embodiment illustrates the case where the ultrasonic transceivers 30 are arranged at each corner of a square, the arrangement of the ultrasonic transceivers 30 is not limited to this. The ultrasonic transceivers 30 may be arranged at positions corresponding to the vertices of a triangle, at the corners of a rhombus, at the corners of a parallelogram, at the corners of a trapezoid, or at the corners of any other polygon. [Explanation of Symbols]

[0124] 100: Ultrasonic anemometer, 30: Multiple ultrasonic transceivers (ultrasonic oscillator, ultrasonic receiver), 31: Ultrasonic transceiver, 32: Ultrasonic transceiver, 33: Ultrasonic transceiver, 34: Ultrasonic transceiver, 200: Measurement unit, 210: Control circuit, 211: CPU (computer).

Claims

1. An ultrasonic oscillator that emits ultrasonic waves, An ultrasonic receiver that receives ultrasonic waves emitted from the ultrasonic oscillator, The system comprises a control circuit for controlling the oscillation of ultrasonic waves by the ultrasonic oscillator and for processing data received by the ultrasonic receiver, The aforementioned control circuit is With respect to the first received data received by the ultrasonic receiver in a state where the ultrasonic oscillator is not emitting ultrasound, the variance is calculated. An ultrasonic anemometer that determines that a high wind speed state is occurring, where the wind speed is higher than a first reference value, when the value obtained by the aforementioned variance exceeds a first judgment threshold.

2. The aforementioned control circuit is When the high wind speed condition is met, the first wind speed is calculated based on the result of the ultrasonic receiver receiving the ultrasonic waves emitted by the ultrasonic oscillator. The ultrasonic anemometer according to claim 1, wherein if the first wind speed calculated is lower than a first reference value, the first wind speed calculated is determined to be an abnormal value.

3. The aforementioned control circuit is When the high wind speed condition is not met, the second wind speed is calculated based on the result of the ultrasonic receiver receiving the ultrasonic waves emitted by the ultrasonic oscillator. The ultrasonic anemometer according to claim 1, wherein if the second wind speed, which is the result of the calculation, is higher than the first reference value, it is determined that the second wind speed, which is the result of the calculation, is an abnormal value.

4. The aforementioned control circuit is The ultrasonic oscillator is capable of performing a first function to prevent false detection of receiver wind speed under specific conditions, The ultrasonic anemometer according to claim 2 or 3, wherein the first function is not performed when the high wind speed condition is present.

5. The aforementioned control circuit is The ultrasonic oscillator is capable of performing a first function to prevent false detection of receiver wind speed under specific conditions, When the high wind speed condition is present, the ultrasonic receiver receives second received data from the ultrasonic oscillator that emits ultrasonic waves, and the system determines whether or not to perform the first function. The ultrasonic anemometer according to claim 3, which performs the first function when the high wind speed condition is not met.

6. The aforementioned control circuit is A second function for preventing erroneous detection of wind speed when the ultrasonic receiver receives ultrasonic waves emitted by the ultrasonic oscillator, the second function for preventing erroneous detection of wind speed can be executed based on temperature. The ultrasonic anemometer according to claim 4, which performs the second function when the high wind speed condition is present.

7. The aforementioned control circuit is In the aforementioned high wind speed condition, a third function can be executed, which calculates the wind speed and wind direction based on the result of the ultrasonic receiver receiving the ultrasonic waves emitted by the ultrasonic oscillator, and stores the first wind direction data related to the wind direction, which is the result of the calculation. The ultrasonic anemometer according to claim 2, wherein the receiver determines that the first wind speed is an abnormal value, and the third function is not performed.

8. The aforementioned control circuit is In the aforementioned high wind speed condition, a third function can be executed, which calculates the wind speed and wind direction based on the result of the ultrasonic receiver receiving the ultrasonic waves emitted by the ultrasonic oscillator, and stores the first wind direction data related to the wind direction, which is the result of the calculation. The ultrasonic anemometer according to claim 3, wherein the third function is not performed when the second wind speed is determined to be an abnormal value.

9. The aforementioned control circuit is The steps include receiving first received data with the ultrasonic receiver while the ultrasonic oscillator is not emitting ultrasonic waves, After receiving the first received data, the ultrasonic oscillator emits ultrasonic waves and the ultrasonic receiver receives the second received data, and the following steps are performed: The aforementioned control circuit is The ultrasonic anemometer according to claim 1, wherein the step of receiving the first received data and the step of receiving the second received data are performed alternately multiple times.

10. The ultrasonic oscillator includes a first ultrasonic oscillator, a second ultrasonic oscillator, and an nth ultrasonic oscillator. The ultrasonic receiver includes a first ultrasonic receiver, a second ultrasonic receiver, and an nth ultrasonic receiver. The aforementioned n is a natural number greater than or equal to 3, The aforementioned control circuit is The steps include receiving first received data with the first ultrasonic receiver while the ultrasonic oscillator is not emitting ultrasonic waves, The first ultrasonic receiver receives the first received data, and then the first ultrasonic oscillator emits ultrasonic waves to receive the second received data, The steps include: receiving the first received data with the second ultrasonic receiver while the ultrasonic oscillator is not emitting ultrasonic waves; The steps include: receiving the first received data with the second ultrasonic receiver, then emitting ultrasonic waves with the second ultrasonic oscillator and receiving the second received data with the second ultrasonic receiver; The steps include receiving the first received data with the n ultrasonic receiver while the ultrasonic oscillator is not emitting ultrasonic waves, The ultrasonic anemometer according to claim 1, which performs the steps of receiving the first received data with the n ultrasonic receiver, and then emitting ultrasonic waves with the n ultrasonic oscillator to receive the second received data with the n ultrasonic receiver.

11. A program that causes a computer to perform a process of measuring wind speed using an ultrasonic anemometer as described in claim 1, The aforementioned program, The process involves calculating the variance of the first received data received by the ultrasonic receiver when the ultrasonic oscillator is not emitting ultrasound, If the value obtained by the aforementioned variance exceeds the first judgment threshold, a process is performed to determine that the wind speed is higher than the first reference value, i.e., a high wind speed state. In the case of the aforementioned high wind speed condition, the process involves calculating a first wind speed based on the result of the ultrasonic receiver receiving the ultrasonic waves emitted by the ultrasonic oscillator, If the calculated first wind speed is lower than the first reference value, the process determines that the calculated first wind speed is an abnormal value. A process to output the first wind speed, which is the result of the calculation, if the first wind speed is a value higher than the first reference value, A program that causes the aforementioned computer to execute.

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