Wind measuring device, wind measuring method, and wind measuring program

Abstract

A wind measuring device (10) comprises ultrasonic sensors (11a, 11c), ultrasonic sensors (11b, 11d), a measurement region (A1), and a wind microcomputer (18). The ultrasonic sensors (11a, 11c) emit ultrasonic waves in a prescribed direction. The ultrasonic sensors (11b, 11d) receive the ultrasonic waves emitted from the ultrasonic sensors (11a, 11c). The measurement region (A1) is provided between the ultrasonic sensors (11a, 11c) and the ultrasonic sensors (11b, 11d). In a prescribed period shorter than the time during which the ultrasonic waves propagate three times between the emission side and the reception side after the ultrasonic waves have been emitted from the ultrasonic sensors (11a, 11c), the wind microcomputer (18) measures the wind speed and the wind direction in the measurement region (A1) on the basis of a change in the reception timing of the ultrasonic waves received by the ultrasonic sensors (11b, 11d).

Description

Wind measurement device, wind measurement method, and wind measurement program

[0001] The present invention relates to a wind measurement device, a wind measurement method, and a wind measurement program for measuring wind speed and direction.

[0002] In recent years, wind speed sensors have been installed as weather sensors to measure wind speed and direction outdoors. For example, Patent Document 1 discloses a wind speed and direction sensor using ultrasonic waves. This wind speed and direction sensor includes a transmitter that emits ultrasonic waves, a first receiver that receives the ultrasonic waves emitted from the transmitter and detects their arrival and reflects the ultrasonic waves, and a second receiver that receives the ultrasonic waves reflected by the first receiver and detects their arrival. The direction and / or speed of airflow between the transmitter and the second receiver and the first receiver are calculated based on the propagation time of the ultrasonic waves from the transmitter to the first receiver and the propagation time of the ultrasonic waves from the first receiver to the second receiver.

[0003] JP 2013-79891 A

[0004] However, the above-mentioned conventional wind direction and speed sensor has the following problem: In the wind direction and speed sensor disclosed in the above publication, there is a risk of multiple reflection interference occurring between the wave transmitter that emits ultrasonic waves and the first and second wave receivers that receive the ultrasonic waves emitted from the wave transmitter, in which the ultrasonic waves emitted from the wave transmitter travel back and forth between the wave transmitter and the wave receivers.

[0005] When such multiple reflection interference occurs, the ultrasonic waves received by the receiver may be mixed with ultrasonic waves that were previously emitted, resulting in a deterioration in measurement accuracy.The object of the present invention is to provide a wind measurement device, a wind measurement method, and a wind measurement program that are capable of measuring wind speed with high accuracy by eliminating the influence of multiple reflection interference between an emitter that emits ultrasonic waves and a receiver that receives the emitted ultrasonic waves.

[0006] (Means for Solving the Problem) A wind measurement device according to a first aspect of the present invention is a wind measurement device that measures wind speed and direction, and includes an emitter, a receiver, a measurement area, and the measurement unit. The emitter emits ultrasonic waves in a predetermined direction. The receiver receives the ultrasonic waves emitted from the emitter. The measurement area is located between the emitter and the receiver. The measurement unit measures wind speed and direction in the measurement area based on changes in the reception timing of the ultrasonic waves received by the receiver, for a predetermined period of time that is shorter than the time it takes for the ultrasonic waves to propagate three times between the emitter and the receiver after they are emitted from the emitter.

[0007] Here, in order to avoid being affected by multiple reflection interference, the measurement unit measures the wind speed and direction in the measurement area based on changes in the reception timing of the ultrasonic waves received by the receiving unit for a predetermined period of time that is shorter than the time it takes for the ultrasonic waves to propagate three times between the emitting unit and the receiving unit after being emitted from the emitting unit.

[0008] Here, the emitter and receiver may function as, for example, a single ultrasonic sensor, or dedicated components may be used as the emitter and receiver. The ultrasonic waves emitted from the emitter may be received directly by the receiver, or may be received via, for example, a reflecting surface provided at a position facing the emitter and receiver.

[0009] The pair of emitter and receiver may be configured as two sets, one set, or three or more sets. The measurement unit measures wind speed and direction by detecting a difference (phase difference) in the reception timing, for example, based on the timing at which the ultrasonic waves emitted from the emitter are received by the receiver in a windless state.

[0010] Multiple reflection interference, which reduces the accuracy of measurement results, refers to a phenomenon in which ultrasonic waves emitted from the emitter are received by the receiver, then return to the emitter, and are received by the receiver as a third propagating wave together with the ultrasonic waves emitted from the emitter. This makes it possible to measure wind speed and direction based on the reception data of ultrasonic waves received only for a predetermined period of time before they are affected by multiple reflection interference (before the time has passed since the ultrasonic waves were emitted from the emitter and the ultrasonic waves have propagated three times between the emitter and the receiver).

[0011] As a result, the influence of multiple reflection interference between the emitting section that emits ultrasonic waves and the receiving section that receives the emitted ultrasonic waves can be eliminated, and the wind speed can be measured with high accuracy.

[0012] A wind measurement device according to a second aspect of the present invention is the wind measurement device according to the first aspect of the present invention, wherein the predetermined period is set according to the propagation distance of the ultrasonic waves emitted from the emitting unit until they are received by the receiving unit. This allows the reception timing and reception period of the ultrasonic waves used for measurement in the measuring unit to be set according to the length of the ultrasonic path (propagation distance) from the emitting unit to the receiving unit (for example, the size of the wind measurement device, the presence or absence of a reflector, etc.), making it possible to eliminate the influence of multiple reflection interference and measure wind speed with high accuracy.

[0013] A wind measurement device according to a third aspect of the present invention is the wind measurement device according to the first or second aspect of the present invention, wherein the start time of the predetermined period is a period during which the amplitude of the ultrasonic waves received by the receiving unit exceeds a predetermined threshold and stabilizes. As a result, the predetermined period used to measure wind speed and the like starts after the amplitude of the ultrasonic waves received by the receiving unit has increased, exceeded the predetermined threshold, and stabilized, thereby eliminating the effects of multiple reflection interference and enabling wind speed to be measured with high accuracy.

[0014] A fourth aspect of the present invention is a wind measurement device according to the first or second aspect of the present invention, wherein the measurement unit measures wind speed and direction using ultrasonic data received by the receiving unit for a predetermined number of pulses over a predetermined period of time. This allows the wind speed and direction to be measured using the reception results of the predetermined number of pulses received by the receiving unit depending on, for example, the length of the ultrasonic path (propagation distance) from the emitting unit to the receiving unit (e.g., the size of the wind measurement device, the presence or absence of a reflector, etc.), thereby eliminating the influence of multiple reflection interference and enabling highly accurate measurement of wind speed.

[0015] A wind measuring device according to a fifth aspect of the present invention is the wind measuring device according to the first or second aspect of the present invention, further comprising a reflecting surface that reflects ultrasonic waves emitted from the emitting unit toward the receiving unit. As a result, the ultrasonic waves irradiated from the emitting unit are received by the receiving unit via the reflecting surface, and wind speed and wind direction can be measured according to the deviation from the reception timing at the receiving unit in a windless state.

[0016] A wind measurement device according to a sixth aspect of the present invention is the wind measurement device according to the fifth aspect of the present invention, wherein the emitting unit and the receiving unit are arranged in line symmetry about the central axis of the reflecting surface, so that the ultrasonic waves emitted from the emitting unit can be efficiently received by the receiving unit.

[0017] A seventh aspect of the present invention is the wind measurement device of the first or second aspect of the present invention, wherein two pairs of emitters and receivers are provided. As a result, for example, by arranging the two pairs of emitters and receivers at 90 degrees to each other, it is possible to accurately measure the speed and direction of wind blowing into the measurement area from all directions of 360 degrees.

[0018] The wind measurement device according to an eighth aspect of the present invention is the wind measurement device according to the first or second aspect of the present invention, wherein the emitter and receiver are a pair of ultrasonic sensors that are switchable between each other. This allows a highly accurate wind measurement device to be configured with a simple configuration by using a single ultrasonic sensor and switching between its functions as the emitter and receiver.

[0019] A ninth aspect of the present invention provides a wind measurement method for measuring wind speed and direction using a wind measurement device, the method comprising: an emission step, a reception step, and a measurement step. In the emission step, an emission unit of the wind measurement device emits ultrasonic waves in a predetermined direction. In the reception step, a reception unit of the wind measurement device receives the ultrasonic waves emitted from the emission unit. In the measurement step, the measurement unit of the wind measurement device measures wind speed and wind direction in a measurement region between the emission unit and the reception unit based on changes in the reception timing of the ultrasonic waves received by the reception unit during a predetermined period of time that is shorter than the time it takes for the ultrasonic waves to propagate three times between the emission unit and the reception unit after the ultrasonic waves are emitted from the emission unit.

[0020] Here, in order to avoid being affected by multiple reflection interference, the measurement unit measures the wind speed and direction in the measurement area based on changes in the reception timing of the ultrasonic waves received by the receiving unit for a predetermined period of time that is shorter than the time it takes for the ultrasonic waves to propagate three times between the emitting unit and the receiving unit after being emitted from the emitting unit.

[0021] Here, the emitter and receiver may function as, for example, a single ultrasonic sensor, or dedicated components may be used as the emitter and receiver. The ultrasonic waves emitted from the emitter may be received directly by the receiver, or may be received via, for example, a reflecting surface provided at a position facing the emitter and receiver.

[0022] The pair of emitter and receiver may be configured as two sets, one set, or three or more sets. The measurement unit measures wind speed and direction by detecting a difference (phase difference) in the reception timing, for example, based on the timing at which the ultrasonic waves emitted from the emitter are received by the receiver in a windless state.

[0023] Multiple reflection interference, which reduces the accuracy of measurement results, refers to a phenomenon in which ultrasonic waves emitted from the emission part are received by the receiving part, then return to the emission part again, and are received by the receiving part as a third propagating wave together with the ultrasonic waves emitted from the emission part.

[0024] This makes it possible to measure wind speed and direction based on reception data of ultrasonic waves received by the receiving unit only for a predetermined period before they are affected by multiple reflection interference (before the time has passed since the ultrasonic waves were emitted from the emitting unit and the ultrasonic waves propagate three times between the emitting unit and the receiving unit).As a result, it is possible to measure wind speed with high accuracy by eliminating the influence of multiple reflection interference between the emitting unit that emits ultrasonic waves and the receiving unit that receives the emitted ultrasonic waves.

[0025] A tenth aspect of the present invention provides a wind measurement program for causing a computer to execute a wind measurement method for measuring wind speed and direction using a wind measurement device, the method comprising: an emission step, a reception step, and a measurement step. In the emission step, an emission unit of the wind measurement device emits ultrasonic waves in a predetermined direction. In the reception step, a reception unit of the wind measurement device receives the ultrasonic waves emitted from the emission unit. In the measurement step, the measurement unit of the wind measurement device measures wind speed and direction in a measurement area based on changes in the reception timing of the ultrasonic waves received by the reception unit for a predetermined period of time that is shorter than the time it takes for the ultrasonic waves to propagate three times between the emission unit and the reception unit after the ultrasonic waves are emitted from the emission unit.

[0026] Here, in order to avoid being affected by multiple reflection interference, the measurement unit measures the wind speed and direction in the measurement area based on changes in the reception timing of the ultrasonic waves received by the receiving unit for a predetermined period of time that is shorter than the time it takes for the ultrasonic waves to propagate three times between the emitting unit and the receiving unit after being emitted from the emitting unit.

[0027] Here, the emitter and receiver may function as, for example, a single ultrasonic sensor, or dedicated components may be used as the emitter and receiver. The ultrasonic waves emitted from the emitter may be received directly by the receiver, or may be received via, for example, a reflecting surface provided at a position facing the emitter and receiver.

[0028] The pair of emitter and receiver may be configured as two sets, one set, or three or more sets. The measurement unit measures wind speed and direction by detecting a difference (phase difference) in the reception timing, for example, based on the timing at which the ultrasonic waves emitted from the emitter are received by the receiver in a windless state.

[0029] Multiple reflection interference, which reduces the accuracy of measurement results, refers to a phenomenon in which ultrasonic waves emitted from the emission part are received by the receiving part, then return to the emission part again, and are received by the receiving part as a third propagating wave together with the ultrasonic waves emitted from the emission part.

[0030] This makes it possible to measure wind speed and direction based on reception data of ultrasonic waves received by the receiving unit only for a predetermined period before they are affected by multiple reflection interference (before the time has passed since the ultrasonic waves were emitted from the emitting unit and the ultrasonic waves propagate three times between the emitting unit and the receiving unit).As a result, it is possible to measure wind speed with high accuracy by eliminating the influence of multiple reflection interference between the emitting unit that emits ultrasonic waves and the receiving unit that receives the emitted ultrasonic waves.

[0031] (Effects of the Invention) The wind measurement device according to the present invention can measure wind speed with high accuracy by eliminating the influence of multiple reflection interference between the emitting section that emits ultrasonic waves and the receiving section that receives the emitted ultrasonic waves.

[0032] 1 is a perspective view showing the overall configuration of a wind measurement device according to an embodiment of the present invention. It is a side view of the wind measurement device of FIG. 1. It is a top view of the wind measurement device of FIG. 1. It is a cross-sectional view along line A-A of FIG. 3. It is a control block diagram of the wind measurement device of FIG. 1. It is a schematic diagram showing the influence of wind when the ultrasonic sensor of FIG. 5 emits ultrasonic waves via a reflecting surface to an ultrasonic sensor arranged opposite to the ultrasonic sensor. It is a schematic diagram showing a configuration in which the ultrasonic sensors included in the wind measurement device of FIG. 5 are arranged in the east-west and north-south directions so as to face each other. It is a diagram explaining the principle of measuring wind speed by detecting a change in the phase difference, relative to a windless state, in the reception timing of ultrasonic waves emitted from the ultrasonic sensor of FIG. 7. It is a graph showing changes in the emission timing from the emitting ultrasonic sensor, the reception timing of ultrasonic waves at the receiving ultrasonic sensor, and the reception voltage of the received ultrasonic waves. It is a flowchart showing the processing flow of a wind measurement method for measuring wind speed and wind direction using the wind measurement device of FIG. 1. It is a flowchart showing the detailed processing flow of the wind measurement method in steps S11 to S14 of FIG.

[0033] A wind measurement device 10 according to one embodiment of the present invention will be described below with reference to FIGS. 1 to 11. Note that in this embodiment, more detailed explanation than necessary may be omitted. For example, detailed explanations of well-known matters or redundant explanations of substantially identical configurations may be omitted. This is to avoid unnecessary redundancy in the following explanation and to facilitate understanding by those skilled in the art.

[0034] Furthermore, the applicant provides the accompanying drawings and the following description to enable those skilled in the art to fully understand the present invention, and they are not intended to limit the subject matter described in the claims.

[0035] (1) Configuration of the wind measurement device 10 As shown in Figures 1 and 2, the wind measurement device 10 of this embodiment measures the speed and direction of wind passing through the gap between the top plate 10a and the base 12 (measurement area A1 (see Figure 4)).

[0036] In the following description, ultrasonic sensors 11a and 11c are described as emitting ultrasonic sensors and ultrasonic sensors 11b and 11d are described as receiving ultrasonic sensors, but because ultrasonic sensors 11a to 11d can be switched between transmitting and receiving, the positions of the emitting and receiving ultrasonic sensors may actually be reversed. Specifically, as shown in Figures 1 and 2, wind measurement device 10 includes top plate 10a, a pair of ultrasonic sensors (emitting unit, receiving unit) 11a and 11b and a pair of ultrasonic sensors (emitting unit, receiving unit) 11c and 11d arranged facing each other, base 12, reflecting surface 13, pillar member 14, and base portion 15.

[0037] As shown in Figures 1 and 3, the top plate 10a is a substantially circular member that forms the top surface of the wind measurement device 10, and is supported from the base 12 by four pillar members 14. The ultrasonic sensors (emitter and receiver) 11a, 11b, 11c, and 11d are disposed on the upper surface 12a of the base 12, as shown in Figure 1 etc. The ultrasonic sensors 11a, 11b, 11c, and 11d are used in pairs (ultrasonic sensors 11a, 11b and ultrasonic sensors 11c, 11d) that are disposed facing each other.

[0038] One of the pair of ultrasonic sensors 11a, 11b functions as an emitter that emits ultrasonic waves, and the other functions as a receiver that receives ultrasonic waves. These functions can also be switched in reverse. For example, when ultrasonic sensor 11a emits ultrasonic waves, ultrasonic sensor 11b, which is positioned opposite to ultrasonic sensor 11a, receives the ultrasonic waves emitted from ultrasonic sensor 11a and reflected by reflecting surface 13 (see FIG. 4).

[0039] When ultrasonic sensor 11b emits an ultrasonic wave, ultrasonic sensor 11a, which is positioned opposite ultrasonic sensor 11b, receives the ultrasonic wave emitted from ultrasonic sensor 11b and reflected by reflecting surface 13 (see FIG. 4). Similarly, when ultrasonic sensor 11c emits an ultrasonic wave, ultrasonic sensor 11d, which is positioned opposite ultrasonic sensor 11c, receives the ultrasonic wave emitted from ultrasonic sensor 11c and reflected by reflecting surface 13 (see FIG. 4).

[0040] When ultrasonic sensor 11d emits ultrasonic waves, ultrasonic sensor 11c, which is positioned opposite ultrasonic sensor 11d, receives the ultrasonic waves emitted from ultrasonic sensor 11d and reflected by reflecting surface 13 (see FIG. 4). As shown in FIG. 4, reflecting surface 13 is provided in the center of the back surface of tabletop 10a facing four ultrasonic sensors 11a, 11b, 11c, and 11d, and reflects ultrasonic waves emitted from ultrasonic sensors 11a and 11c on the emitting side, and guides the ultrasonic waves to ultrasonic sensors 11b and 11d on the receiving side, which are positioned opposite ultrasonic sensors 11a and 11c on the emitting side.

[0041] As shown in Fig. 1 etc., the pillar members 14 are erected on the top surface 12a on which the ultrasonic sensors 11a, 11b, 11c, and 11d are arranged, and are provided around the measurement area A1 to support the top plate 10a from below, as shown in Fig. 4. As shown in Fig. 4, the base portion 15 is provided on the top surface 12a on which the ultrasonic sensors 11a, 11b, 11c, and 11d are arranged, and protrudes from the top surface 12a while supporting the ultrasonic sensors 11a, 11b, 11c, and 11d.

[0042] Furthermore, as shown in Figure 5, the wind measurement device 10 of this embodiment is equipped with ultrasonic driving units 16a, 16b, 16c, 16d, a logic IC (Integrated Circuit) 17a, a multiplexer 17b, an ultrasonic sensor IC 17c, a wind microcomputer (measurement unit) 18, and a memory 18a, in addition to the configuration of the ultrasonic sensors (emitter, receiver) 11a, 11b, 11c, 11d, etc. described above.

[0043] The ultrasonic driving units 16a, 16b, 16c, and 16d each have an ultrasonic sensor driving IC that converts a logic signal (0-3.3V differential pulse signal) during transmission into an ultrasonic driving signal (0-18V), and controls the driving of the four ultrasonic sensors 11a, 11b, 11c, and 11d while switching between them using the wind microcomputer 18. The logic IC 17a, for example, has an enable function, generates switching and differential input, and inputs it to the ultrasonic sensor driving IC.

[0044] The multiplexer 17b is connected to the ultrasonic sensors 11a, 11b, 11c, and 11d. The multiplexer 17b acquires the ultrasonic wave values ​​measured by the ultrasonic sensors 11a, 11b, 11c, and 11d, which function as receivers, while switching between them. The multiplexer 17b transmits the measured ultrasonic wave values ​​as analog signals to the ultrasonic sensor IC 17c. The ultrasonic sensor IC 17c filters noise and functions as, for example, a bandpass filter that passes only the received signals of the ultrasonic sensors 11b and 11d on the receiving side. Furthermore, the ultrasonic sensor IC 17c functions as an amplifier that amplifies the received signals of the ultrasonic sensors 11b and 11d on the receiving side. The ultrasonic sensor IC 17c also functions as a comparator that generates pulse signals from the received signals of the ultrasonic sensors 11b and 11d on the receiving side and inputs the pulse signals to the wind microcomputer 18.

[0045] The wind microcomputer (measurement unit) 18 measures the wind speed and direction in the measurement area A1 based on, for example, changes in the reception timing of ultrasonic waves received by the ultrasonic sensors 11b and 11d functioning as receivers. In order to perform measurements at a timing that is not affected by multiple reflection interference, the wind microcomputer 18 performs measurements using reception data of ultrasonic waves received by the receiving ultrasonic sensors 11b and 11d for a predetermined period that is shorter than the time it takes for the ultrasonic waves to propagate three times between the emitter and receiver after being emitted from the emitting ultrasonic sensors 11a and 11c.

[0046] The method for measuring wind speed and wind direction in the wind microcomputer 18 will be described in detail later. The memory 18a stores, for example, data on wind speed and wind direction measured by the wind microcomputer 18, and formulas for measuring wind speed and wind direction.

[0047] <Wind measurement principle> The wind measurement device 10 of this embodiment is equipped with four ultrasonic sensors 11a, 11b, 11c, and 11d, which are switched to function as emitters and receivers to measure the speed and direction of wind in the measurement area A1.

[0048] Specifically, the wind measurement device 10 utilizes the fact that the time it takes for an emitted ultrasonic wave to be received between a pair of ultrasonic sensors 11a and 11b or ultrasonic sensors 11c and 11d arranged opposite each other changes between when there is no wind and when there is wind, as shown in Figure 6, and calculates the wind speed by finding the change as the phase difference when the ultrasonic wave is received.

[0049] For example, as shown in Fig. 6, when wind is blowing from left to right in the figure, ultrasonic waves emitted from the ultrasonic sensors 11a and 11c on the emitting side are received earlier by the ultrasonic sensors 11b and 11d on the receiving side, which are arranged opposite to them, compared to when there is no wind. On the other hand, in contrast to Fig. 6, when wind is blowing from right to left in the figure, ultrasonic waves emitted from the ultrasonic sensors 11a and 11c on the emitting side are received later by the ultrasonic sensors 11b and 11d on the receiving side, which are arranged opposite to them, compared to when there is no wind.

[0050] The wind speed Vab between the ultrasonic sensors 11a and 11b shown in FIG. 7 is calculated by the following formula. The same applies to the wind speed Vcd between the ultrasonic sensors 11c and 11d. Vab=Δt×(c ２ ) / (2 × d) where Δt = (Tab: change in phase difference on the outbound path) - (Tba: change in phase difference on the return path) c = speed of sound d = distance between ultrasonic sensors Therefore, the wind measurement device 10 can measure the wind speed by calculating the time Δt of change in phase difference compared to a windless state.

[0051] Furthermore, in order to calculate the direction of the wind passing through the measurement area A1, the wind measurement device 10 adds up the measurement results Vab and Vcd of the paired ultrasonic sensors 11a, 11b and the paired ultrasonic sensors 11c, 11d to calculate the final wind speed V and wind direction θ. V = a × √((Vab) ２ +(Vcd) ２ ) θ = tan －１ (Vab / Vcd) where a is the wind direction dependent correction coefficient with θ as a variable

[0052] <Control of Acquisition Timing of Received Data for Measurement> As described above, the wind measurement device 10 of this embodiment measures wind speed and wind direction in the measurement area A1 between the emitting ultrasonic sensors 11 a, 11 b and the receiving ultrasonic sensors 11 c, 11 d, which are arranged opposite each other. In order to eliminate the influence of multiple reflection interference of ultrasonic waves in the measurement area A1, the wind measurement device 10 uses the wind microcomputer 18 to set a predetermined reception period (start timing and length) for the receiving ultrasonic sensors 11 b, 11 d, and measures wind speed and wind direction using data received during that reception period.

[0053] Here, multiple reflection interference refers to a phenomenon in which ultrasonic waves emitted from the ultrasonic sensors 11a and 11c on the emitting side are received by the ultrasonic sensors 11b and 11d on the receiving side via the reflecting surface 13, and then return to the ultrasonic sensors 11a and 11c on the emitting side via the reflecting surface 13 again, and are received by the ultrasonic sensors 11b and 11d on the receiving side via the reflecting surface 13 as a third propagating wave, together with the ultrasonic waves emitted from the ultrasonic sensors 11a and 11c on the emitting side.

[0054] When multiple reflection interference occurs, the receiving ultrasonic sensors 11b and 11d mix the ultrasonic waves that should be received with the multiple reflections, making it difficult to accurately measure wind speed and direction. Therefore, in the wind measurement device 10 of this embodiment, the wind microcomputer 18 acquires the data of ultrasonic waves received by the receiving ultrasonic sensors 11b and 11d, and measures the wind speed and direction in the measurement area A1 using the data of ultrasonic waves received by the receiving ultrasonic sensors 11b and 11d for a predetermined period of time that is shorter than the time it takes for the ultrasonic waves to propagate three times between the transmitting and receiving ultrasonic sensors 11a and 11c and the ultrasonic sensors 11b and 11d.

[0055] Specifically, the wind microcomputer 18 transmits a transmission voltage (pulse wave) to the ultrasonic sensors 11a and 11c on the emission side at regular intervals, as shown in the top row of Fig. 9. In response to this, the ultrasonic sensors 11a and 11c on the emission side receive the transmission voltage from the wind microcomputer 18 and emit ultrasonic waves having a waveform whose amplitude gradually increases, as in the emission wave shown in the second row from the top of Fig. 9.

[0056] Subsequently, the receiving-side ultrasonic sensors 11b and 11d receive the ultrasonic waves emitted from the emitting-side ultrasonic sensors 11a and 11c after a predetermined propagation time has elapsed, as shown in the third row of Fig. 9. At this time, the predetermined propagation time is the time it takes for the ultrasonic waves from the emitting-side ultrasonic sensors 11a and 11c to be received by the receiving-side ultrasonic sensors 11b and 11d, and varies depending on the length of the distance 2L from the emitting-side ultrasonic sensors 11a and 11c to the receiving-side ultrasonic sensors 11b and 11d via the reflecting surface 13.

[0057] The receiving ultrasonic sensors 11b and 11d then receive ultrasonic waves having a waveform whose amplitude gradually increases, similar to the emitted waves from the emitting ultrasonic sensors 11a and 11c, as shown in the third row of Fig. 9. Here, the effect of multiple reflection interference occurs when the multiply reflected ultrasonic waves propagate for the third time, from the emitting side to the receiving side (via the reflecting surface 13), from the receiving side to the emitting side (via the reflecting surface 13), and from the emitting side to the receiving side (via the reflecting surface 13), and therefore, after a certain amount of time has passed in the waveform shown in the third row of Fig. 9, an effect such as an increase in the amplitude of the waveform occurs.

[0058] For this reason, in the wind measurement device 10 of this embodiment, the wind microcomputer 18 measures wind speed and direction using received data from the receiving ultrasonic sensors 11b and 11d during a period when the waveforms of the ultrasonic waves are stable, before the effects of multiple reflection interference begin to occur. The conditions for not being affected by multiple reflection interference are as follows: That is, if the drive frequency of the emitting ultrasonic sensors 11a and 11c is f, the speed of sound is c, and the propagation distance of the ultrasonic waves is 2L, then the distance (wavelength) that the ultrasonic waves travel in one cycle is c / f.

[0059] Therefore, the ratio of the propagation distance of ultrasonic waves to the distance traveled in one cycle is N = 2L / (c / f) = 2L × (f / c). In other words, N cycles after the time when the ultrasonic sensors 11a and 11c on the emitting side start to emit ultrasonic waves, the ultrasonic sensors 11b and 11d on the receiving side receive the ultrasonic waves. From the above, the condition for not being affected by multiple reflection interference is the time when the ultrasonic waves reflected from the ultrasonic sensors 11b and 11d on the receiving side and the ultrasonic sensors 11a and 11c on the emitting side reach the receiving side again (3 × N cycles later).

[0060] Specifically, the wind microcomputer 18 measures wind speed and direction using data from a predetermined period (dashed line portion) during which the received voltage at the receiving ultrasonic sensors 11b and 11d is stable, as shown in the fourth and bottom rows of Fig. 9. Here, the received data used for measurement is acquired during a predetermined period from the N1th cycle to the N2th cycle after the transmission voltage of the wind microcomputer 18 is transmitted, as shown in Fig. 9.

[0061] Taking into consideration the propagation time of ultrasonic waves from the emitting side to the receiving side, N1 and N2 are set according to the distance 2L from the emitting ultrasonic sensors 11a and 11c to the receiving ultrasonic sensors 11b and 11d via the reflecting surface 13. Furthermore, as shown in the fourth row of Fig. 9, N1 and N2 are set on the condition that the amplitude of the received voltage at the receiving ultrasonic sensors 11b and 11d exceeds predetermined thresholds +Vth and -Vth.

[0062] Furthermore, after ultrasonic waves are emitted from the emitting ultrasonic sensors 11 a, 11 c (transmission voltage is transmitted), the wind microcomputer 18 measures wind speed and direction using the reception data of ultrasonic waves received by the receiving ultrasonic sensors 11 b, 11 d during the period from the N1th cycle to the N2th cycle. This allows the wind microcomputer 18 to measure wind speed and direction using the data received by the receiving ultrasonic sensors 11 b, 11 d during a period when the amplitude of the waveform of the reception data is stable and when there is no influence from multiple reflection interference, thereby eliminating the degradation of measurement accuracy due to multiple reflection interference and enabling highly accurate measurements.

[0063] That is, wind direction and speed can be calculated from the received voltage in the N1 to N2 cycles of counting transmitted pulses (the timing when the received voltage of the ultrasonic sensor exceeds Vth and is not affected by multiple reflection interference). Although it is possible to calculate wind direction and speed using just one cycle, data redundancy can be increased by calculating wind direction and speed using two or more cycles.

[0064] <Wind measurement method> The wind measurement device 10 of this embodiment carries out a wind measurement method in accordance with the flowcharts shown in Figures 10 and 11. In the following description, for example, ultrasonic sensor A corresponds to ultrasonic sensor 11a, ultrasonic sensor B corresponds to ultrasonic sensor 11b, ultrasonic sensor C corresponds to ultrasonic sensor 11c, and ultrasonic sensor D corresponds to ultrasonic sensor 11d.

[0065] 10, in step S11, ultrasonic waves emitted from the emitting ultrasonic sensor A (11a) to the receiving ultrasonic sensor B (11b) are measured by the receiving ultrasonic sensor B (11b). Next, in step S12, ultrasonic waves emitted from the emitting ultrasonic sensor C (11c) to the receiving ultrasonic sensor D (11d) are measured by the receiving ultrasonic sensor D (11d).

[0066] Next, in step S13, ultrasonic waves emitted from the emitting ultrasonic sensor B (11b) to the receiving ultrasonic sensor A (11a) are measured by the receiving ultrasonic sensor A (11a). Next, in step S14, ultrasonic waves emitted from the emitting ultrasonic sensor D (11d) to the receiving ultrasonic sensor C (11c) are measured by the receiving ultrasonic sensor C (11c).

[0067] The details of the measurements in steps S11 to S14 will be described later with reference to Fig. 11. Next, in step S15, the wind microcomputer 18 calculates Vab and Vcd from the received voltages at the receiving ultrasonic sensors A to D from the N1th cycle to the N2th cycle after the ultrasonic waves are emitted from the emitting ultrasonic sensors A to D, out of the received data measured in steps S11 to S14.

[0068] Specifically, as described above, N1 and N2 are set in consideration of the propagation time of the ultrasonic waves from the emission side to the reception side, according to the length of the distance 2L from the emission side to the reception side via the reflecting surface 13. Furthermore, N1 and N2 are set on the condition that the amplitude of the received voltage on the reception side exceeds predetermined thresholds +Vth and −Vth.

[0069] Next, in step S16, the wind speed V and wind direction θ are calculated based on Vab and Vcd calculated in step S15. The measurement process from the emission of ultrasonic waves from the emission side to the reception side to their reception will be described in more detail below with reference to Figure 11. That is, in step S21, a control voltage is input from the wind microcomputer 18 via the logic IC 17a to the ultrasonic driver 16a, 16b, 16c, or 16d that emits ultrasonic waves.

[0070] Next, in step S22, the ultrasonic driver 16a, 16b, 16c, or 16d to which the control voltage was input in step S21 outputs a drive voltage to the ultrasonic sensor 11a, 11b, 11c, or 11d. Next, in step S23, the ultrasonic sensor 11a, 11b, 11c, or 11d to which the drive voltage was input in step S22 outputs an ultrasonic wave.

[0071] Next, in step S24, the ultrasonic sensor 11b, 11a, 11d, or 11c disposed opposite the ultrasonic sensor 11a, 11b, 11c, or 11d that output the ultrasonic wave in step S23 receives the ultrasonic wave. Next, in step S25, the received voltage received by the receiving ultrasonic sensor 11b, 11a, 11d, or 11c passes through the multiplexer 17b.

[0072] Next, in step S26, the ultrasonic sensor IC 17c removes noise from the received voltage that has passed through the multiplexer 17b (band-pass filter function), and then in step S27, the ultrasonic sensor IC 17c amplifies the received voltage from which noise has been removed (amplifier function).

[0073] Next, in step S28, the ultrasonic sensor IC 17c converts the amplified received voltage into a square wave (comparator function). Next, in step S29, the wind microcomputer 18 receives the square wave converted in step S28 and ends the measurement.

[0074] <Major Features> The wind measurement device 10 of this embodiment is a device that measures wind speed and direction, and as shown in FIG. 5 , includes ultrasonic sensors 11a and 11c, ultrasonic sensors 11b and 11d, a measurement area A1, and a wind microcomputer 18. The ultrasonic sensors 11a and 11c emit ultrasonic waves in a predetermined direction. The ultrasonic sensors 11b and 11d receive the ultrasonic waves emitted from the ultrasonic sensors 11a and 11c. The measurement area A1 is located between the ultrasonic sensors 11a and 11c and the ultrasonic sensors 11b and 11d. The wind microcomputer 18 measures the wind speed and wind direction in the measurement area A1 based on changes in the reception timing of the ultrasonic waves received by the ultrasonic sensors 11b and 11d during a predetermined period of time that is shorter than the time it takes for the ultrasonic waves to propagate three times between the emission side and the reception side after the ultrasonic sensors 11a and 11c emit ultrasonic waves.

[0075] This allows wind speed and direction to be measured based on the reception data of ultrasonic waves received by ultrasonic sensors 11b and 11d at a predetermined timing for a predetermined period before they are affected by multiple reflection interference. As a result, wind speed can be measured with high accuracy by eliminating the influence of multiple reflection interference between ultrasonic sensors 11a and 11c that emit ultrasonic waves and ultrasonic sensors 11b and 11d that receive the emitted ultrasonic waves.

[0076] [Other Embodiments] Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the invention. (A) In the above embodiment, examples in which the present invention is realized as a wind measurement device and a wind measurement method have been described. However, the present invention is not limited to this.

[0077] For example, the present invention may be realized as a wind measurement program that causes a computer to execute the wind measurement method using the wind measurement device described above. This wind measurement program is stored in a memory (storage unit) installed in the wind measurement device, and a CPU reads the wind measurement program stored in the memory and causes the hardware to execute each step. More specifically, the same effect as above can be achieved by having the CPU read the wind measurement program and execute the above-mentioned emission step, reception step, and measurement step. The present invention may also be realized as a recording medium that stores the wind measurement program.

[0078] (B) In the above embodiment, an example was described in which the timing for acquiring reception data for measuring wind speed and direction is determined by detecting a period in which the amplitude of the reception data is stable using a threshold value, and measuring wind speed and direction using reception data from the N1 to N2 cycles received by the receiving ultrasonic sensors 11b and 11d during a period that is not affected by multiple reflection interference. However, the present invention is not limited to this.

[0079] For example, the wind speed and direction may be measured using the received data from the N1th cycle to the N2th cycle, when the amplitude of the waveform of the received data reaches a stable period, without using a threshold value. Alternatively, the wind speed and direction may be measured using the received data from reception until the influence of multiple reflection interference occurs, regardless of the stability of the amplitude of the waveform of the received data.

[0080] (C) In the above embodiment, an example was described in which the wind measurement device 10 includes two pairs of ultrasonic sensors 11a, 11b, 11c, and 11d, for a total of four. However, the present invention is not limited to this. For example, the wind measurement device may be configured with three ultrasonic sensors.

[0081] In this case, the ultrasonic sensors are arranged at approximately equal angular intervals and function as emitters and receivers, making it possible to measure the wind speed and direction in the measurement area between the three points. Also, the wind measurement device may be configured with two or five or more ultrasonic sensors.

[0082] (D) In ​​the above embodiment, an example was described in which the ultrasonic sensors 11a, 11b and the ultrasonic sensors 11c, 11d arranged opposite each other can switch between functioning as an emitter and a receiver. However, the present invention is not limited to this. For example, an ultrasonic sensor dedicated to emitting and an ultrasonic sensor dedicated to receiving may be arranged opposite each other.

[0083] (E) In the above embodiment, an example was described in which ultrasonic waves are received between two opposing ultrasonic sensors 11a and 11b or two opposing ultrasonic sensors 11c and 11d via the reflecting surface 13. However, the present invention is not limited to this. For example, ultrasonic waves may be received directly between the opposing ultrasonic sensors without passing through a reflecting surface.

[0084] <Note> The wind measurement device of the first invention is a wind measurement device that measures wind speed and wind direction, and comprises: an emission unit that emits ultrasonic waves in a predetermined direction; a receiving unit that receives the ultrasonic waves emitted from the emission unit; a measurement area provided between the emission unit and the receiving unit; and a measurement unit that measures wind speed and wind direction in the measurement area based on changes in the reception timing of the ultrasonic waves received by the receiving unit during a predetermined period that is shorter than the time it takes for the ultrasonic waves to propagate three times between the emission unit and the receiving unit after being emitted from the emission unit.

[0085] A second aspect of the present invention is the wind measurement device of the first aspect, wherein the predetermined period is set according to a propagation distance of ultrasonic waves emitted from the emission unit until they are received by the reception unit. A third aspect of the present invention is the wind measurement device of the first or second aspect, wherein the start time of the predetermined period is the timing when the amplitude of the ultrasonic waves received by the reception unit exceeds a predetermined threshold.

[0086] A fourth aspect of the present invention is the wind measurement device of any one of the first to third aspects, wherein the measurement unit measures the wind speed and wind direction using data on ultrasonic waves received by the receiving unit for a predetermined pulse amount during the predetermined period. A fifth aspect of the present invention is the wind measurement device of any one of the first to fourth aspects, further comprising a reflecting surface that reflects the ultrasonic waves emitted from the emitting unit in the direction of the receiving unit.

[0087] A sixth aspect of the present invention is the wind measurement device of the fifth aspect, wherein the emitting unit and the receiving unit are arranged symmetrically about the central axis of the reflecting surface.A seventh aspect of the present invention is the wind measurement device of any one of the first to sixth aspects, wherein the emitting unit and the receiving unit are provided in two pairs.

[0088] The wind measurement device according to an eighth aspect of the present invention is the wind measurement device according to any one of the first to seventh aspects of the present invention, wherein the emission unit and the reception unit are ultrasonic sensors that are used in a switchable state and are provided as a pair.

[0089] The wind measurement device of the present invention has the effect of being able to measure wind speed with high accuracy by eliminating the effects of multiple reflection interference between the emitting section that emits ultrasonic waves and the receiving section that receives the emitted ultrasonic waves, and therefore can be widely applied to ultrasonic sensor-type wind direction and speed measurement devices installed in weather sensors, etc.

[0090] 10 Wind measurement device 10a Top plate 11a, 11b, 11c, 11d Ultrasonic sensor (emitting part, receiving part) 12 Base 12a Top surface 13 Reflecting surface 14 Pillar member 15 Base part 16a, 16b, 16c, 16d Ultrasonic driving part 17a Logic IC 17b Multiplexer 17c Ultrasonic sensor IC 18 Wind microcomputer (measuring part) 18a Memory (storage part) A1 Measurement area

Claims

1. A wind measurement device that measures wind speed and direction, comprising: an emission unit that emits ultrasonic waves in a predetermined direction; a receiving unit that receives the ultrasonic waves emitted from the emission unit; a measurement area provided between the emission unit and the receiving unit; and a measurement unit that measures wind speed and direction in the measurement area based on changes in the reception timing of ultrasonic waves received by the receiving unit during a predetermined period of time that is shorter than the time it takes for the ultrasonic waves to propagate three times between the emission unit and the receiving unit after being emitted from the emission unit.

2. The wind measurement device according to claim 1, wherein the predetermined period is set according to the propagation distance of ultrasonic waves emitted from the emitting unit until they are received by the receiving unit.

3. The wind measurement device according to claim 1 or 2, wherein the start time of the predetermined period is the timing when the amplitude of the ultrasonic waves received by the receiving unit exceeds a predetermined threshold.

4. The wind measurement device according to claim 1 or 2, wherein the measurement unit measures the wind speed and wind direction using ultrasonic data received by the receiving unit for a predetermined number of pulses during the predetermined period.

5. The wind measuring device according to claim 1 or 2, further comprising a reflecting surface that reflects the ultrasonic waves emitted from the emitting section in the direction of the receiving section.

6. The wind measurement device according to claim 5, wherein the emitting unit and the receiving unit are arranged symmetrically with respect to a center axis of the reflecting surface.

7. The wind measuring device according to claim 1 or 2, wherein the emitting unit and the receiving unit are provided in two pairs.

8. The wind measuring device according to claim 1 or 2, wherein the emission unit and the reception unit are ultrasonic sensors that are provided as a pair and are used in a switchable state.

9. A wind measurement method for measuring wind speed and direction using a wind measurement device, comprising: an emission step in which an emission unit of the wind measurement device emits ultrasonic waves in a predetermined direction; a reception step in which a receiving unit of the wind measurement device receives the ultrasonic waves emitted from the emission unit; and a measurement step in which a measurement unit of the wind measurement device measures wind speed and wind direction in a measurement area between the emission unit and the receiving unit based on changes in the reception timing of the ultrasonic waves received by the receiving unit for a predetermined period of time that is shorter than the time it takes for the ultrasonic waves to propagate three times between the emission unit and the receiving unit after the ultrasonic waves are emitted from the emission unit.

10. A wind measurement program that causes a computer to execute a wind measurement method for measuring wind speed and direction using a wind measurement device, comprising: an emission step in which an emission unit of the wind measurement device emits ultrasonic waves in a predetermined direction; a reception step in which a receiving unit of the wind measurement device receives the ultrasonic waves emitted from the emission unit; and a measurement step in which the measurement unit of the wind measurement device measures the wind speed and wind direction in the measurement area between the emission unit and the receiving unit based on changes in the reception timing of the ultrasonic waves received by the receiving unit for a predetermined period of time that is shorter than the time it takes for the ultrasonic waves to propagate three times between the emission unit and the receiving unit after the ultrasonic waves are emitted from the emission unit.

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