JP7102830B2 - Wind direction and speed measuring device - Google Patents

Description

The present invention relates to a wind direction and wind speed measuring device that measures a wind direction and a wind speed.

In recent years, attention has been focused on the construction of a distribution network using a small unmanned multicopter that can be remotely controlled, a so-called drone. If distribution services using drones can be put into practical use, further industrial development can be expected, such as compensation for labor shortages and delivery to mountainous areas, which tend to be stagnant. Aiming at the construction of such a distribution network, the applicants have announced the "drone highway concept". The drone highway concept is based on the idea of using the sky above the transmission network, including transmission towers and transmission lines, as a dedicated air route for drones in order to secure a flight route for drones.

In order to fly a drone safely, it is necessary to observe detailed weather information on the air route such as wind direction and speed. However, the transmission tower has a height of about 50 to 100 m, and the drone highway will fly higher than that. The meteorological information measured by the Japan Meteorological Agency and each organization is mainly related to the ground surface, and the wind speed and direction are different from the ground surface at such high places, so the data obtained from the conventional equipment is not useful. In addition, although meteorological information is observed relatively densely in areas with high population densities, facilities for measuring detailed meteorological information with low population densities such as mountainous areas are not in place. Therefore, in the above drone highway concept, it is planned to install a wind direction and speed measuring device at an outdoor high place such as a power transmission tower.

As a wind direction and anemometer that are widely used at present, a mechanical type that detects the rotation of a wind turbine or a wind cup and obtains a measured value is well known. For example, in the wind speed monitoring device described in Patent Document 1, a plurality of wind cups are provided outdoors in order to obtain a wind speed value. Other types of anemometers include ultrasonic type anemometers that use the propagation time of ultrasonic waves to determine the wind speed, hot wire type anemometers that use the temperature at which the heating wire heats up and cools to determine the wind speed, and more. There is also known a Pitot tube type that obtains the wind speed from the dynamic pressure of the wind using a Pitot tube.

Japanese Unexamined Patent Publication No. 2018-4364

In order to install the wind direction and speed measuring device in a high place outdoors, there is a demand for reducing the number of moving parts as much as possible in order to reduce the risk of failure in addition to being compact and lightweight. In addition, it is necessary to consider means for collecting the measured data.

In view of such problems, it is an object of the present invention to provide a wind direction and wind speed measuring device which has a compact and lightweight configuration and can be suitably installed outdoors.

In order to solve the above problems, a typical configuration of the wind direction and wind speed measuring device according to the present invention includes an arrow blade that indicates the direction in which the wind blows, a sensor that detects an electric signal according to the direction of the arrow blade, and a unit time. It is characterized by including a calculation unit that calculates the wind direction in that time zone from the average value of the electric signals around it and calculates the wind speed in that time zone from the frequency of the vibration of the fletching that appears in the waveform of the electric signal. ..

In the conventional arrow blade type wind direction meter, the vibration of the arrow blade interferes with the measurement, so measures such as giving the arrow blade a certain weight have been taken. In addition, since the anemometer using the wind cup may interfere with the anemometer, it was installed at a distance from the anemometer. However, the inventors of the present application have focused on the fact that the vibration of the arrow blade is due to the Karman vortex and its frequency is proportional to the velocity, and have come up with a configuration in which the wind velocity is calculated from the frequency of the vibration of the arrow blade. .. According to this configuration, the arrow blades move less than the constantly rotating wind cup, and the overall structure is small, and the wind direction measurement by the arrow blades is averaged over that period as long as the frequency is known. This eliminates the need to suppress vibration, so a lighter and more concise structure is sufficient. Therefore, with the above configuration, it is possible to realize a wind direction / wind speed measuring device that is small and lightweight, can be easily installed in a high place outdoors, and has less concern about failure.

The wind direction and speed measuring device may further include a solar cell that obtains electric power and a wireless communication unit that transmits data on the wind direction and speed and also relays data from other devices by a multi-hop connection.

According to the above configuration, it is not necessary to prepare an external power supply, and the measured data can be easily collected. Therefore, with the above configuration, it can be suitably installed even in a high place outdoors, and by installing a plurality of units, it is possible to efficiently acquire wind direction and wind speed information along a predetermined route.

According to the present invention, it is possible to provide a wind direction and wind speed measuring device that can be suitably installed outdoors with a simple configuration.

It is a figure which showed the outline of the wind direction wind speed measuring apparatus which concerns on embodiment of this invention. It is a figure which showed the schematic internal structure of the measuring device. It is a figure which shows the relationship between the frequency of the electric signal acquired from the wind direction sensor, and the wind speed.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in such an embodiment are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are designated by the same reference numerals to omit duplicate description, and elements not directly related to the present invention are not shown. do.

FIG. 1 is a diagram showing an outline of a wind direction and wind speed measuring device (measuring device 100) according to an embodiment of the present invention. FIG. 1A is a perspective view showing the entire measuring device 100. The measuring device 100 has a configuration that imitates a small arrow vane type wind direction meter, and can measure not only the wind direction but also the wind speed. It is assumed that a plurality of measuring devices 100 are mainly installed outdoors, such as a power transmission tower or a rooftop of a building.

The measuring device 100 is apparently composed of a pedestal 100a and an arrow blade 100b. The pedestal 100a is fixed to a measurement point such as a power transmission tower, and the arrow blade 100b is provided freely rotatably with respect to the pedestal 100a. The arrow blade 100b points to a windward siege when the tail wing 102 perpendicular to the pedestal 100a turns to the leeward side and the tip 104 faces the leeward side.

The pedestal 100a and the arrow blade 100b are made of a lightweight resin, and are made of a highly weather-resistant material that is not easily deteriorated by rainwater or ultraviolet rays, for example, by subjecting polycarbonate to a predetermined surface treatment. In particular, the arrow blade 100b has a very lightweight structure that reacts to even a slight wind, and the pedestal 100a is highly waterproof and can fully protect electronic components such as the wind direction sensor 106, which will be described later, from rainwater and the like. It is possible.

FIG. 1B is a diagram showing a state in which the measuring device 100 is in operation. FIG. 1B illustrates a situation in which the wind W is blowing from left to right. In the present embodiment, the wind direction is measured based on the direction of the arrow blade 100b, but the wind speed is measured based on the vibration generated in the arrow blade 100b. As an overview, in general, when an object is placed in a flow, a vortex called Karman vortex R, which is oriented in alternating left and right directions, is generated downstream of the object. Then, the Karman vortex R causes slight vibration (unstable) in the arrow blade 100b. At this time, the number of Karman vortices R affects the degree of vibration of the arrow blade 100b, and the number of vortices generated per unit time is proportional to the flow velocity. The measuring device 100 uses these phenomena to calculate the wind speed from the frequency of vibration of the arrow blade 100b.

FIG. 2 is a diagram showing a schematic internal configuration of the measuring device 100. Among the measuring devices 100, various electronic components are built in particularly inside the pedestal 100a. First, the wind direction sensor 106 detects an electric signal according to the direction of the arrow blade 100b, and can be realized by, for example, a magnetic sensor that detects the rotation of the arrow blade 100b 104b using magnetism.

The calculation unit 108 calculates the wind direction and the wind speed from the electric signal acquired through the wind direction sensor 106. For example, the calculation of the wind direction in the target time zone can be performed by calculating the average value of the electric signals per unit time and determining the direction corresponding to the value. On the other hand, the calculation of the wind speed in the target time zone is performed by calculating the frequency of the vibration of the arrow blade 100b. As described above, the vibration of the fletching 100b is due to the Karman vortex, and its frequency is reflected in the frequency of the waveform of the electric signal obtained from the wind direction sensor 106. Therefore, by analyzing the frequency of this electric signal, The wind speed can be derived.

FIG. 3 is a diagram showing the relationship between the frequency and the wind speed of the electric signal acquired from the wind direction sensor 106. Here, it is known that the frequency at which the Karman vortex R (see FIG. 1A) is generated is denied to the velocity of the fluid, and its relational expression is expressed as the following equation 1.
f = St · V / d ... Equation 1
(F is the vortex frequency, V is the average flow velocity of the fluid, d is the width of the vortex generator, and St is a constant called the Strouhal number).

When the above equation 1 is applied to the present embodiment, the vortex frequency f is the vibration frequency of the arrow blade 100b (see FIG. 1A), the average flow velocity V is the wind velocity, and the width d of the vortex generator is the tail blade 102 of the arrow blade 100b. Is the width of. The Strouhal number St varies depending on a numerical value that defines a flow state including characteristics such as inertia and viscosity, which is called a Reynolds number, and is substantially constant over a wide range of this Reynolds number. That is, the above equation 1 expresses that the frequency f of the vibration of the arrow blade 100b is proportional to the wind speed V by regarding the Strouhal number St as constant.

In the present embodiment, the calculation unit 108 (see FIG. 2) extracts a high-intensity frequency component from the electric signal detected by the wind direction sensor 106 by Fast Fourier Transform Analysis (hereinafter referred to as FFT analysis). The wind speed is calculated from it. For example, FIG. 3A is a diagram showing the results of FFT analysis of vibration (waveform of an electric signal corresponding to the vibration of the arrow blade 100b) at a wind speed of 3 m / s. The horizontal axis is the frequency, and the vertical axis is the intensity of the frequency component. From FIG. 3A, it can be seen that the maximum peak occurs in the vicinity of about 2.3 Hz when the wind speed is 3 m / s.

Similarly, FIG. 3B is a diagram showing the results of FFT analysis of vibration at a wind speed of 12 m / s. In FIG. 3B, it can be seen that the maximum peak occurs near about 7 Hz. Further, FIG. 3C is a diagram showing the results of FFT analysis of vibration at a wind speed of 24 m / s. From FIG. 3C, it can be seen that the maximum peak occurs in the vicinity of about 12.5 Hz.

FIG. 3D is a diagram showing the relationship between the maximum peak and the wind speed. In FIG. 3D, the horizontal axis is the frequency and the vertical axis is the wind speed. Each plot shows the frequency of the maximum peak at each wind speed obtained by FFT analysis. From FIG. 3D, it can be confirmed that there is a correlation between the frequency and the wind speed. This proves that the wind speed can be calculated if the frequency of vibration of the fletching 100b (see FIG. 1A) is known. In this way, the calculation unit 108 (see FIG. 2) calculates the wind speed from the electric signal detected by the wind direction sensor 106.

See FIG. 2 again. The measuring device 100 is provided with a communication unit 110. The communication unit 110 connects to an external terminal or the like via, for example, a wireless LAN, and transmits measurement data related to the wind direction and speed calculated by the calculation unit 108. Further, the communication unit 110 can be multi-hop connected to another measuring device, and can also relay various data transmitted from the other measuring device and transmit it to an external terminal or the like. There is.

In the above, the connection between the measuring device 100 and the external terminal or the like is wireless, but if the external terminal is nearby, a wired connection may be made. In either method, by sending data on the wind direction and the wind speed from the measuring device 100 to the external terminal, it is possible to provide the measurement result in a representation that can be visually recognized by the user through a monitor or the like.

The measuring device 100 may include a solar cell or a capacitor (not shown) as a means for obtaining electric power, which eliminates the need for an external power source or wiring. The solar cell can be appropriately installed at a position susceptible to sunlight, such as the upper surface of the pedestal 100a (see FIG. 1A). Since the measuring device 100 uses the lightweight arrow blade 100b, the structure is simple and the amount of electricity used can be small. Therefore, the measuring device 100 is power-saving, and even if the usage amounts of the wind direction sensor 106 (see FIG. 2), the calculation unit 108, the communication unit 110, and the like are combined, the required power can be sufficiently covered by the solar cell. be.

As described above, the measuring device 100 has a compact and lightweight configuration and can be suitably installed outdoors. In the conventional arrow blade type wind direction meter, the vibration of the arrow blade interferes with the measurement, so measures such as giving the arrow blade a certain weight have been taken. However, in the case of the measuring device 100, it is not necessary to suppress the vibration of the arrow blade 100b by averaging over the period of the frequency of the arrow blade 100b or more. In addition, the fletching 100b has less movement than the constantly rotating cup. Therefore, the measuring device 100 has a smaller overall structure, is lighter, and is simpler. In this way, the measuring device 100 is compact and lightweight, can be easily installed at a high place outdoors, and has a configuration in which there is little concern about failure.

As described above, the measuring device 100 is lightweight and does not require an external power source, and the measured data can also be collected wirelessly. In addition, it is made of resin and is resistant to rainwater, and the use of metal parts is suppressed, so there is less concern about lightning strikes. Therefore, the measuring device 100 can maintain a long service life even when it is installed in an outdoor high place such as a power transmission tower. As an operation example of the measuring device 100, when a route connecting a plurality of power transmission towers is used as an air route of a drone, a measuring device 100 is installed in each power transmission tower to acquire wind direction and wind speed information in the route. It can be very useful as an air route management system.

Although preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such examples. It is clear that a person skilled in the art can come up with various modifications or modifications within the scope of the claims, which naturally belong to the technical scope of the present invention. Understood.

The present invention can be used as a wind direction and wind speed measuring device for measuring a wind direction and a wind speed.

100 ... Measuring device, 100a ... Pedestal, 100b ... Arrow blade, 102 ... Tail wing, 104 ... Wind direction sensor, 108 ... Calculation unit, 110 ... Communication unit, R ... Karman vortex, W ... Wind

Claims (1)

An arrow feather that points to the direction in which the wind blows,
A sensor that detects an electrical signal according to the direction of the arrow blade,
A calculation unit that calculates the wind direction of the time zone from the average value of the electric signal per unit time, and calculates the wind speed of the time zone from the frequency of the vibration of the arrow blade appearing in the waveform of the electric signal.
With
The arithmetic unit extracts the maximum frequency peak from the electric signal detected by the sensor by fast Fourier transform analysis and obtains it as the vortex frequency of the Karman vortex.
When f is the vortex frequency of the Karman vortex, V is the average flow velocity of the fluid, d is the width of the vortex generator, and St is the Strouhal number, the following equation
f = St · V / d
A wind direction and wind speed measuring device characterized in that the wind speed is calculated using .

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