Wind measurement device and weather sensor provided with same

Abstract

Provided is a wind measurement device (10) comprising ultrasonic sensors (11a, 11b, 11c, 11d), a measurement region (A1), an air microcomputer (18), and a reflection surface (13). The ultrasonic sensors (11b, 11d) receive the ultrasonic waves radiated from the ultrasonic sensors (11a, 11c). The measurement region (A1) is provided between the ultrasonic sensors (11a, 11b, 11c, 11d). The wind microcomputer (18) measures the wind speed and the wind direction in the measurement region (A1) on the basis of the change in the reception timing of the ultrasonic waves received by the ultrasonic sensors (11b, 11d). The reflection surface (13) reflects the ultrasonic waves radiated from the ultrasonic sensors (11a, 11c) and guides the ultrasonic waves in the direction of the ultrasonic sensors (11b, 11d), and has a semi-elliptical shape in a side cross-sectional view, and the ultrasonic sensors (11a, 11b, 11c, 11d) are disposed at semi-elliptical focus positions.

Description

Wind measuring device and weather sensor equipped with same

[0001] The present invention relates to a wind measuring device that measures wind speed and direction, and a weather sensor equipped with the same.

[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 an anemometer in which two pairs of ultrasonic sensors are arranged on the upper surface of a base board and measure wind direction and speed by detecting the reflection of ultrasonic waves emitted from a flat roof board.

[0003] Japanese Patent Application Laid-Open No. 2017-20830

[0004] However, the above-mentioned conventional anemometer has the following problems. In the anemometer disclosed in the above publication, the reflective surface of the roof panel that reflects ultrasonic waves is flat, so if the ultrasonic waves are blown away by wind, the amount of ultrasonic waves received by the receiver may decrease, resulting in a decrease in the accuracy of the measurement value. The object of the present invention is to provide a wind measurement device and a weather sensor equipped with the same that can reduce the decrease in accuracy of the measurement value even when affected by wind.

[0005] (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, the measurement area, and a reflecting surface. 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 area measures wind speed and direction in the measurement area based on changes in the reception timing of the ultrasonic waves received by the receiver. The reflecting surface reflects the ultrasonic waves emitted from the emitter and guides them toward the receiver, and has a semi-elliptical shape in a side cross-sectional view, with the emitter and receiver being located at the focal position of the semi-elliptical shape.

[0006] In this wind measurement device, ultrasonic waves emitted from an emitter are received by a receiver via a reflecting surface, the reflecting surface is semi-elliptical, and the emitter and receiver are disposed at the focal point of the semi-elliptical shape. Here, the emitter and receiver may function as the emitter and receiver using a single ultrasonic sensor, or dedicated components may be used as the emitter and receiver.

[0007] 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.

[0008] The device has the characteristic that light emitted from one focal point of an elliptical shape surrounded by a mirror surface is reflected by the mirror surface and travels toward the other focal point. As a result, even if the ultrasonic waves emitted from the emitter are affected by wind and the reflection position on the reflecting surface shifts, the ultrasonic waves reflected on the reflecting surface can be efficiently received by the receiver because the emitter and receiver are located at the semi-elliptical focal points. As a result, even when affected by wind, the accuracy of the measurement value can be reduced.

[0009] 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, in which the emitting unit and the receiving unit are arranged symmetrically 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.

[0010] 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, in which 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.

[0011] 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 emitter and receiver are a pair of ultrasonic sensors that can be switched between each other. This allows a single ultrasonic sensor to be used while switching between its functions as the emitter and receiver, thereby enabling a highly accurate wind measurement device to be configured with a simple configuration.

[0012] A wind measurement device according to a fifth aspect of the present invention is the wind measurement device according to the first or second aspect of the present invention, further comprising a base portion provided on the first surface on which the emitting portion and the receiving portion are arranged and protruding from the first surface to support the emitting portion and the receiving portion. In this configuration, in which the base portion supporting the emitting portion and the receiving portion protrudes from the first surface, the speed and direction of the wind can be detected by emitting and receiving ultrasonic waves.

[0013] 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 base supports the emitting portion and the receiving portion at an angle with respect to the first surface so that ultrasonic waves are emitted from the emitting portion at an angle with respect to the first surface and received by the receiving portion via the reflecting surface at an angle with respect to the first surface. This allows the receiving portion to efficiently receive the reflection of the ultrasonic waves emitted from the emitting portion at an angle with respect to the reflecting surface.

[0014] A weather sensor according to a seventh aspect of the present invention includes the wind measurement device according to the first or second aspect of the present invention and a raindrop detection device for measuring rainfall, thereby providing a weather sensor that can reduce the decrease in accuracy of measurement values ​​even when affected by the above-mentioned wind.

[0015] Effect of the Invention According to the wind measurement device of the present invention, even when it is affected by wind, it is possible to reduce the decrease in accuracy of the measurement value.

[0016] 1 is an overall perspective view showing the configuration of a weather sensor including a wind measurement device according to an embodiment of the present invention. FIG. 1 is a side view of the weather sensor of FIG. 1. FIG. 2 is a top view of the weather sensor of FIG. 1. FIG. 3 is a cross-sectional view showing the configuration of the upper section of the weather sensor (raindrop detection device) in the cross-sectional view taken along line A-A in FIG. 3. FIG. 4 is a control block diagram of the wind measurement device included in the weather sensor of FIG. 1. FIG. 5 is a cross-sectional view showing the configuration of the middle section of the weather sensor (wind measurement device) in the cross-sectional view taken along line A-A in FIG. 3. FIG. 6 is a schematic diagram showing the influence of wind when the ultrasonic sensor of FIG. 6 emits ultrasonic waves via a reflecting surface to an ultrasonic sensor arranged opposite it. FIG. 7 is a schematic diagram showing the configuration of ultrasonic sensors included in the wind measurement device of FIG. 6 arranged so as to face each other. FIG. 8 is a diagram explaining the principle of measuring wind speed by detecting a change in the phase difference, based on a windless state, in the reception timing of ultrasonic waves emitted from the ultrasonic sensor of FIG. 7. FIG. 9 is a schematic diagram showing how ultrasonic waves emitted from the ultrasonic sensor of FIG. 7 are received by the ultrasonic sensor arranged opposite it by a semi-elliptical reflecting surface, even when fluctuated by wind. (a) is a side view showing a state in which ultrasonic waves are emitted to a flat reflecting surface as a comparative example and received by an ultrasonic sensor arranged opposite the surface; (b) is a graph showing a composite detection signal received by the receiving ultrasonic sensor in the configuration of (a); (c) is a side view showing a state in which ultrasonic waves are emitted to a semi-elliptical reflecting surface of this embodiment and received by an ultrasonic sensor arranged opposite the surface; and (d) is a graph showing a composite detection signal received by the receiving ultrasonic sensor in the configuration of (c).

[0017] A wind measurement device according to one embodiment of the present invention will be described below with reference to FIGS. 1 to 11(d). 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. Furthermore, the applicant provides the accompanying drawings and the following explanation to enable those skilled in the art to fully understand the present invention, and does not intend for them to limit the subject matter recited in the claims.

[0018] (1) Configuration of the weather sensor 1 The weather sensor 1 according to this embodiment is a device that is installed, for example, outdoors and measures rain, wind, illuminance, temperature, humidity, air pressure, etc., and as shown in Figures 1 and 2, it includes a wind measurement device 10, a raindrop detection device 20, an illuminance meter 30, and a thermo-hygro-barometer 40.

[0019] As shown in FIGS. 1 and 2 , the wind measurement device 10 is provided in the middle section of the weather sensor 1 and measures the speed and direction of wind passing through the gap (measurement area A1 (see FIG. 6 )) between the raindrop detection device 20 and the thermo-hygro-barometer 40. The detailed configuration of the wind measurement device 10 will be described later. As shown in FIGS. 1 and 2 , the raindrop detection device 20 is provided in the upper section of the weather sensor 1 and detects raindrops that pass through a predetermined opening 21 a (see FIG. 3 , etc.) on the top surface of the housing 21, and calculates the amount of rainfall by detecting the size of the detected raindrops and the amount per unit time.

[0020] More specifically, the raindrop detection device 20 has a light source 22a and a light receiving unit 22b (see FIG. 4) inside the housing 21. The light source 22a and the light receiving unit 22b are arranged facing each other on the inner wall surface 21b of the opening 21a, as shown in FIG. 4. The light source 22a is, for example, a light emitting diode (LED), and emits infrared light toward the light receiving unit 22b via a collimating lens and a condensing lens (neither of which are shown).

[0021] The light receiving unit 22b is, for example, a photodiode, and is positioned opposite the light source unit 22a. The light receiving unit 22b receives light condensed through a condensing lens (not shown). The light source unit 22a irradiates a raindrop detection area formed between the light source unit 22a and the light receiving unit 22b with light. The presence or absence of raindrops is detected when raindrops block part of the light detected by the light receiving unit 22b, reducing the amount of light received by the light receiving unit 22b.

[0022] The raindrop detection device 20 has a plurality of legs 23 erected on the upper surface of the base 24, and is connected to the wind measurement device 10 constituting the middle section of the weather sensor 1 via the legs 23 and the base. As shown in Figures 1 and 2, the illuminance meter 30 is provided in the upper section of the weather sensor 1 together with the raindrop detection device 20, and measures illuminance as one piece of weather information. As shown in Figures 1 and 2, the thermo-hygro-barometer 40 is provided in the lower section of the weather sensor 1, and measures temperature (air temperature), humidity, and air pressure as weather information.

[0023] (2) Configuration of the wind measurement device 10 The wind measurement device 10 of this embodiment is a device that measures, for example, outdoor wind speed and wind direction, and as shown in Figure 5, is equipped with ultrasonic sensors (emitter and receiver) 11a, 11b, 11c, and 11d, a pillar member 14 and a base 15 (see Figure 6, etc.), ultrasonic driver units 16a, 16b, 16c, and 16d, a logic IC 17a, a multiplexer 17b, an ultrasonic sensor IC 17c, a wind microcomputer (measurement unit) 18, and a relay microcomputer 19.

[0024] As shown in FIG. 1 and other figures, ultrasonic sensors (emitters, receivers) 11a, 11b, 11c, and 11d are arranged on the upper surface (first surface) 12a of the base 12. The ultrasonic sensors 11a, 11b, 11c, and 11d are used in pairs (ultrasonic sensors 11a and 11b and ultrasonic sensors 11c and 11d) arranged facing each other. One of the pair of ultrasonic sensors 11a and 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.

[0025] For example, when ultrasonic sensor 11a emits an ultrasonic wave, ultrasonic sensor 11b, which is positioned opposite to ultrasonic sensor 11a, receives the ultrasonic wave emitted from ultrasonic sensor 11a and reflected by reflecting surface 13 shown in Fig. 6. When ultrasonic sensor 11b emits an ultrasonic wave, ultrasonic sensor 11a, which is positioned opposite to ultrasonic sensor 11b, receives the ultrasonic wave emitted from ultrasonic sensor 11b and reflected by reflecting surface 13 shown in Fig. 6.

[0026] 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 shown in Fig. 6. When ultrasonic sensor 11d emits an ultrasonic wave, ultrasonic sensor 11c, which is positioned opposite ultrasonic sensor 11c, receives the ultrasonic wave emitted from ultrasonic sensor 11d and reflected by reflecting surface 13 shown in Fig. 6.

[0027] As shown in Fig. 7, the reflecting surface 13 has a semi-elliptical shape in a side cross-sectional view, and guides ultrasonic waves emitted from the emitting ultrasonic sensors 11a and 11c to the receiving ultrasonic sensors 11b and 11d. The reflection of ultrasonic waves by the semi-elliptical reflecting surface 13 will be described in detail later. As shown in Fig. 6, the pillar members 14 are erected on the upper surface 12a on which the ultrasonic sensors 11a, 11b, 11c, and 11d are arranged, are provided around the measurement area A1, and support the base 24 from below.

[0028] 6, the base 15 is provided on the upper surface 12a on which the ultrasonic sensors 11a, 11b, 11c, and 11d are arranged, and protrudes from the upper surface 12a while supporting the ultrasonic sensors 11a, 11b, 11c, and 11d. The ultrasonic driving units 16a, 16b, 16c, and 16d each have an ultrasonic sensor driving IC (Integrated Circuit) that converts a logic signal (0-3.3V differential pulse signal) during transmission into an ultrasonic driving signal (0-18V), and the wind microcomputer 18 controls the driving of the four ultrasonic sensors 11a, 11b, 11c, and 11d while switching between them.

[0029] The logic IC 17a, for example, has an enable function, generates switching and differential inputs, and inputs them to the ultrasonic sensor driving IC. The multiplexer 17b is connected to the ultrasonic sensors 11a, 11b, 11c, and 11d, and acquires the values ​​of ultrasonic waves measured by switching the ultrasonic sensors 11a, 11b, 11c, and 11d that function as receivers, and transmits the values ​​as analog signals to the ultrasonic sensor IC 17c.

[0030] The ultrasonic sensor IC 17c controls the ultrasonic sensors 11a, 11b, 11c, and 11d that function as receivers, while switching between the ultrasonic sensors 11a, 11b, 11c, and 11d using the wind microcomputer 18. The ultrasonic sensor IC 17c also receives and amplifies ultrasonic waves while switching between the ultrasonic sensors 11a, 11b, 11c, and 11d in the multiplexer 17b.

[0031] The wind microcomputer (measurement unit) 18 measures wind speed and direction in the measurement area A1 based on changes in the reception timing of ultrasonic waves received by the ultrasonic sensors 11a, 11b, 11c, and 11d, which function as receivers. The relay microcomputer 19, for example, communicates with the wind microcomputer 18, acquires data from the temperature / humidity and air pressure sensors on other boards, and relays data from the rain sensor board. Note that communication between each microcomputer (wind microcomputer 18, relay microcomputer 19) is performed using, for example, a universal asynchronous receiver / transmitter (UART).

[0032] <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.

[0033] 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 7, and calculates the wind speed by finding the change as the phase difference when the ultrasonic wave is received.

[0034] For example, as shown in Fig. 7, when the wind is blowing from left to right in the figure, the ultrasonic waves emitted from the ultrasonic sensors 11a and 11c are received earlier by the opposing ultrasonic sensors 11b and 11d than when there is no wind. On the other hand, when the wind is blowing from right to left in the figure, contrary to Fig. 7, the ultrasonic waves emitted from the ultrasonic sensors 11a and 11c are received later by the opposing ultrasonic sensors 11b and 11d than when there is no wind.

[0035] The wind speed Vab between the ultrasonic sensors 11a and 11b shown in FIG. 8 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 × L) (m / s) where Δt = (Tab: phase difference change on the return journey) - (Tba: phase difference change on the outgoing journey) (sec) c = speed of sound (m / s) = 331.5 + (0.61 × temperature (°C)) L = distance between sensors (m) Here, as shown in FIG. 9, if the time period during which the phase difference changes on the outgoing journey from the ultrasonic sensors 11a, 11c on the emitting side to the ultrasonic sensors 11b, 11d on the receiving side is Tab (sec), and the time period during which the phase difference changes on the opposite journey from the ultrasonic sensors 11b, 11d on the emitting side to the ultrasonic sensors 11a, 11c on the receiving side is Tba (sec), then the time period during which the phase difference changes compared to when there is no wind is represented as Δt.

[0036] Therefore, the wind measurement device 10 can measure the wind speed by calculating the time Δt of change in the phase difference compared to a windless state. 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 11 a, 11 b and the paired ultrasonic sensors 11 c, 11 d to calculate the final wind speed value and wind direction.

[0037] <Reflection of ultrasonic waves by a reflecting surface and arrangement of ultrasonic sensors> As shown in Fig. 10, the wind measurement device 10 of this embodiment is provided with a reflecting surface 13 having a semi-elliptical shape in a side cross section above the ultrasonic sensors 11a, 11b, 11c, and 11d. The emitting ultrasonic sensors 11a and 11c and the receiving ultrasonic sensors 11b and 11d are arranged at a semi-elliptical focal position F1.

[0038] The ultrasonic sensors 11a, 11b and the ultrasonic sensors 11c, 11d, which are arranged opposite to each other, switch between emitting and receiving at a predetermined timing. The ultrasonic waves emitted from the emitting ultrasonic sensors 11a, 11c are carried by the wind, and as the wind speed increases, the angle of travel relative to the reflecting surface 13 shifts, causing the reflection position on the reflecting surface 13 to move.

[0039] Furthermore, ultrasonic sensors 11a, 11b, 11c, and 11d generally do not have high directivity and emit ultrasonic waves over a wide angle, so the area of ​​the reachable point increases as the distance to reflecting surface 13 increases. Therefore, in the wind measurement device 10 of this embodiment, reflecting surface 13 is made semi-elliptical, and the characteristic that light irradiated from one focal position of the elliptical shape surrounded by mirror surfaces is reflected by the mirror surface and heads toward the other focal position is utilized.

[0040] As a result, the sound waves emitted from the semi-elliptical focal position F1 are reflected by the circumference and directed back toward the focal position F1, so even if the angle of propagation of the ultrasonic waves shifts and the reflection position moves, the ultrasonic waves reflected by the semi-elliptical reflecting surface 13 can be guided to near the central positions of the receiving ultrasonic sensors 11b and 11d, thereby increasing gain. Furthermore, the ultrasonic sensors 11a, 11b, 11c, and 11d are arranged symmetrically about the central axis O of the semi-elliptical reflecting surface 13.

[0041] This allows the ultrasonic sensors 11b and 11d on the receiving side to efficiently receive the ultrasonic waves reflected by the semi-elliptical reflecting surface 13. As a comparative example for verifying the effect of the reflecting surface 13, Fig. 11(a) shows the configuration of a wind measurement device 110 equipped with a flat reflecting surface 113. In this type of wind measurement device 110, the propagation angle of the ultrasonic waves emitted from the ultrasonic sensor 11a changes due to the influence of wind, etc., and the reflection position on the reflecting surface 113 shifts. As a result, the composite detection signal of the ultrasonic waves received by the ultrasonic sensor 11b has a waveform as shown in Fig. 11(b).

[0042] Next, as shown in FIG. 11(c), the wind measurement device 10 of this embodiment is provided with a reflecting surface 13 that is semi-elliptical in cross section from the side. Therefore, even if the angle of travel of the ultrasonic waves emitted from the ultrasonic sensor 11a changes due to the influence of wind or the like, and the reflection position on the reflecting surface 13 shifts, the composite detection signal of the ultrasonic waves received by the ultrasonic sensor 11b will have a waveform higher than the waveform in FIG. 11(b), as shown in FIG. 11(d).

[0043] From the above, in the wind measurement device 10 of this embodiment, a larger gain can be obtained in the receiving ultrasonic sensor 11b compared to the configuration of the wind measurement device 110 having a flat reflecting surface 113, and therefore it is possible to measure wind speed and direction with high accuracy.

[0044] <Major Features> The wind measurement device 10 of this embodiment is a device that measures wind speed and direction and includes ultrasonic sensors 11a, 11b, 11c, and 11d, a measurement area A1, a wind microcomputer 18, and a reflecting surface 13. 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, 11b, 11c, 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. The reflecting surface 13 reflects ultrasonic waves emitted from the ultrasonic sensors 11a and 11c and guides them toward the ultrasonic sensors 11b and 11d. The reflecting surface 13 has a semi-elliptical shape when viewed from the side cross section, and the ultrasonic sensors 11a, 11b, 11c, and 11d are positioned at a focal position F1 of the semi-elliptical shape.

[0045] As a result, even if the ultrasonic waves emitted from the ultrasonic sensors 11a and 11c are affected by wind and the reflection positions on the reflecting surface 13 are shifted, the ultrasonic sensors 11a and 11c and the ultrasonic sensors 11b and 11d are arranged at the semi-elliptical focal position F1, so that the ultrasonic sensors 11b and 11d can efficiently receive the ultrasonic waves reflected on the reflecting surface 13. As a result, even when affected by wind, it is possible to reduce a decrease in the accuracy of the measurement values.

[0046] [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 and scope of the invention. (A) In the above embodiment, an example was given 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.

[0047] For example, the wind measurement device may be configured with three ultrasonic sensors. In this case, each ultrasonic sensor is arranged at approximately equal angular intervals and functions as an emitter and a receiver, making it possible to measure the wind speed and direction in the measurement area between the three points. Alternatively, the wind measurement device may be configured with two ultrasonic sensors or five or more ultrasonic sensors.

[0048] (B) 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 are switchable between functioning as emitters and functions as receivers. 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.

[0049] (C) In the above embodiment, an example has been described in which the ultrasonic sensors 11a, 11b, 11c, and 11d are supported by the base portion 15. However, the present invention is not limited to this. For example, the ultrasonic sensors may be arranged on a plane that is approximately at the same level as the first surface.

[0050] (D) In ​​the above embodiment, the wind measurement device 10 is incorporated into the weather sensor 1. However, the present invention is not limited to this. For example, the wind measurement device may be used as a standalone device.

[0051] <Note> The wind measurement device of the first invention is a wind measurement device that measures wind speed and direction, and includes: 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; 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; and a reflection surface that reflects the ultrasonic waves emitted from the emission unit and guides them toward the receiving unit, and has a semi-elliptical shape in a side cross-sectional view, with the emission unit and the receiving unit being located at focal positions of the semi-elliptical shape.

[0052] A second aspect of the present invention is the wind measurement device of the first aspect, wherein the emitting unit and the receiving unit are arranged symmetrically about the central axis of the reflecting surface. A third aspect of the present invention is the wind measurement device of the first or second aspect, wherein the emitting unit and the receiving unit are provided in two pairs.

[0053] A fourth aspect of the present invention is the wind measurement device according to any one of the first to third aspects, wherein the emitter and the receiver are ultrasonic sensors that are used in a switchable state and are provided as a pair. A fifth aspect of the present invention is the wind measurement device according to any one of the first to fourth aspects, further comprising a base portion that is provided on a first surface on which the emitter and the receiver are arranged, and that protrudes from the first surface to support the emitter and the receiver.

[0054] A sixth aspect of the present invention is the wind measurement device of the fifth aspect, wherein the base supports the emitting portion and the receiving portion at an angle with respect to the first surface so that ultrasonic waves are emitted from the emitting portion at an angle with respect to the first surface and received by the receiving portion at an angle with respect to the first surface via the reflecting surface. A seventh aspect of the present invention is a weather sensor comprising: the wind measurement device of any one of the first to sixth aspects; and a raindrop detection device that measures rainfall.

[0055] The wind measurement device of the present invention has the effect of reducing the decrease in accuracy of measurement values ​​even when affected by wind, and is therefore widely applicable to devices installed in weather sensors, etc.

[0056] DESCRIPTION OF SYMBOLS 1 Weather sensor 10 Wind measurement device 11a, 11b, 11c, 11d Ultrasonic sensor (emitting unit, receiving unit) 12 Base 12a Top surface (first surface) 13 Reflecting surface 14 Pillar member 15 Base 16a, 16b, 16c, 16d Ultrasonic driving unit 17a Logic IC 17b Multiplexer 17c Ultrasonic sensor IC 18 Wind microcomputer (measuring unit) 19 Relay microcomputer 20 Raindrop detection device 21 Housing 21a Opening 21b Inner wall surface 22a Light source unit 22b Light receiving unit 23 Leg 24 Base 30 Illuminance meter 40 Thermo-hygro-barometer A1 Measurement area F1 Focal position O Central axis

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; a measurement unit that measures wind speed and direction in the measurement area based on changes in the reception timing of the ultrasonic waves received by the receiving unit; and a reflective surface that reflects the ultrasonic waves emitted from the emission unit and guides them toward the receiving unit, and has a semi-elliptical shape in a side cross-sectional view, with the emission unit and the receiving unit positioned at the focal position of the semi-elliptical shape.

2. The wind measurement device according to claim 1, wherein the emission unit and the reception unit are arranged symmetrically with respect to a center axis of the reflection surface.

3. The wind measurement device according to claim 1 or 2, wherein the emission section and the reception section are provided in two pairs.

4. The wind measurement device according to claim 1 or 2, wherein the emission unit and the reception unit are ultrasonic sensors provided as a pair and are switchably used with respect to each other.

5. A wind measurement device as described in claim 1 or 2, further comprising a base portion provided on a first surface on which the emitting portion and the receiving portion are arranged and protruding from the first surface so as to support the emitting portion and the receiving portion.

6. The wind measurement device described in claim 5, wherein the base portion supports the emitting portion and the receiving portion at an angle with respect to the first surface so that ultrasonic waves are emitted from the emitting portion at an angle with respect to the first surface and received at the receiving portion at an angle with respect to the first surface via the reflecting surface.

7. A weather sensor comprising: a wind measuring device according to claim 1 or 2; and a raindrop detection device for measuring the amount of rainfall.

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