JPH06194374A - Wind direction/wind speed detector - Google Patents

Abstract

PURPOSE:To provide a wind direction/wind speed detector for detecting wind speed along with wind direction. CONSTITUTION:The wind direction/wind speed detector comprises a first vortex generator 13 having a constant representative length regardless of the wind direction, and a second vortex generator 14 having a representative length variable with the wind direction. Karman's vortexes generated from the vortex generators 13, 14 flow through pressure conduits 23, 24 into chambers 21, 22 where the frequencies of the vortexes are detected by means of microphones 19, 20. Detected signal representative of the frequency is amplified and digitized at a circuit section and wind speed and wind direction are calculated at a wind speed operating section and wind direction operating section in the circuit section according to formulas.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wind direction and wind speed detecting device used for selecting a wind direction and wind speed of an automobile or the like.

[0002]

2. Description of the Related Art Conventionally, an anemometer (vortex flowmeter) utilizing a Karman vortex has been used in order to stably measure the wind speed without being affected by temperature, humidity and pressure.

As an example of an anemometer utilizing this Karman vortex, as disclosed in Japanese Utility Model Publication No. 59-194017, a vortex body is arranged in a flow path into which wind flows, and this vortex body is provided. There is a method in which the generation frequency of the Karman vortex generated in this way is detected and the wind speed is detected based on this generation frequency.

[0004]

However, although the conventional anemometer described above can detect the wind speed,
The wind direction cannot be detected.

Therefore, an object of the present invention is to provide a wind direction and wind speed detecting device which can detect the wind direction as well as the wind speed.

[0006]

In order to achieve the above object, the present invention is a wind direction wind velocity detecting device for detecting the wind direction and velocity of a fluid to be measured, the first vortex forming device having a cylindrical outer shape. A body, a second vortex forming body having a shape in which a representative length, which is a projected width projected by the fluid to be measured, changes according to the wind direction of the fluid to be measured, and a second vortex forming body on the downstream side of the first vortex forming body. The first detection means for detecting the frequency of the generated Karman vortex, the second detection means for detecting the frequency of the Karman vortex generated downstream of the second vortex forming body, and the first detection means. First to calculate the wind speed based on the detected frequency
The wind direction and wind speed detection device is provided, which includes: a calculation unit for calculating the wind direction based on the frequency detected by the first detection unit and the frequency detected by the second detection unit. To do.

[0007]

According to the wind direction / velocity detecting device of the present invention having the above-mentioned structure, the first detecting means detects the frequency of the Karman vortex generated from the first vortex forming body having a cylindrical shape and the representative length of which does not change with the wind direction. And the wind speed is calculated by the first calculation means based on the frequency of this Karman vortex.

By the way, the frequency of the Karman vortex varies depending on the representative length of the vortex body. Therefore, the frequency of the Karman vortex generated from the second vortex body differs depending on the wind direction. If the frequency of this Karman vortex is detected by the second detecting means,
The wind direction can be calculated by the second calculation means based on the frequency of the Karman vortex and the frequency detected by the first detection means.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the wind direction and wind speed detecting device of the present invention will be described below with reference to the drawings. As shown in FIG. 6, this detection device mainly includes a sensor unit 10 mounted outside the vehicle, a circuit unit 30 for calculating the wind speed and the wind direction, and a display unit 50 for indicating the state of traveling wind to the occupant. .

The structure of the sensor section 10 will be described with reference to the perspective view of FIG. 1 and the sectional view of FIG. As shown in FIG. 1, the sensor unit 10 has a hierarchical structure, and a vortex body for generating Karman vortices is arranged in each of the layers 11 and 12.

Of this vortex body, the first vortex body 13 arranged on the upper layer 11 is made of resin and has a columnar shape. The second vortex body 14 arranged in the lower layer is made of resin and has a shape whose representative length changes depending on the direction in which the wind hits, for example, the columnar cylinder portion 141 and the flat fins 1
42 and 143 are attached. Incidentally, the representative length, as shown in FIG. 3 is that the length d of the horizontal width of the projection portion when the wind of the wind direction θ is windage towards Zouzu body, straight pillars d ₁ cylinder In the shape, the representative length d ₂ varies depending on the wind direction θ.

As shown in the sectional view of FIG. 2, the first vortex body 13 is integrally formed with an upper wall 15 and a lower wall 16 for partitioning the upper layer 11. Further, the second vortex body 14 is integrally formed with an upper wall 17 and a lower wall 18 that partition the lower layer 21. Recesses 151 and 171 are provided in the upper portions of the upper side walls 15 and 17, and the recesses 151 and the lower surface of the flat plate-shaped microphone 19 form a space 21 having a predetermined volume. Further, the concave portion 171 and the lower surface of the flat plate-shaped microphone 20 form a space 22 having a predetermined volume. Upper wall 1
Through holes 152 and 172 are provided to connect the recesses 151 and 171 on the upper side of the parts 5 and 17 and the lower space.

Behind the first vortex forming body 13 and the second vortex forming body 14, pressure conduits 23 and 24 made of metal and having a hollow cylindrical shape are respectively installed in order to transmit the pressure fluctuation of the Karman vortex. The side walls 15 and 17 are press-fitted into the through holes 152 and 172.
An upper case 25 made of resin and having a recess 251 into which the microphone 19 can be inserted is provided on the upper side wall 15. The microphone 19 fitted into the upper case 25 is a piezoelectric piezoelectric microphone corresponding to the first detecting means of the present invention, and its pressure detecting portion faces the space 21 above the first vortex body 13. There is.

A recess 161 into which the microphone 20 can be inserted is provided in the lower portion of the lower side wall 16 formed integrally with the first vortex body 13, and the microphone 20 is fitted into this recess 161. This microphone 20 corresponds to the second detecting means of the present invention, and is the vortex body 1
The pressure detecting portion of the microphone 20 is fitted so as to face the space 22 in the upper portion of the microphone 4. The pressure detected by the microphones 19 and 20 is connected to the circuit unit 30 via the wiring cord 26. The wiring cord 26 is inserted into the through hole 181 provided in the lower side wall 18 of the lower portion of the second vortex body 14,
Bush 27 made of rubber and provided with through holes 271
Through the sensor 10 to the outside of the sensor 10. Vortex body 13, 1
A rectifying grid 2 which is a resin-made plate-shaped fin on the outer periphery of 4
8 are arranged at equal intervals and concentrically.

Next, the structure of the circuit section 30 will be described with reference to FIG. In the circuit section 30, the pressures detected by the microphones 19 and 20 are input to the CPU 33 through the amplifier 31 for amplification and the comparator 32 for detecting and comparing signals, respectively. A filter 33 for removing noise is provided in the CPU 33.
1 is provided, frequency F-voltage V conversion is performed based on the pressure signal from which noise has been removed by this filter 331, the vortex generation frequency is detected, and the first value of the present invention is determined from the voltage value indicating the frequency of this signal. Wind speed calculation unit 33 corresponding to the calculation means of
3 and the wind direction calculation unit 334 corresponding to the second calculation means of the present invention calculates the wind speed and the wind direction by the calculation described later in detail.

Next, the operation of the wind direction and wind speed detecting device having the above-mentioned structure will be described with reference to FIGS. As shown in FIG. 3, when the sensor unit 10 receives wind having a wind speed v and a wind direction θ, the wind is rectified by the rectifying grid 28, and the vortex generators 13 and 14 are formed.
On the other hand, Karman vortices are generated alternately from the rear side of the vortex generators 13 and 14 to the left and right. This Karman vortex is generated in a specific cycle, and the vortex generation frequency f is expressed by the following equation.

[0017]

[Equation 1] Here, St is the Strouhal number, and is a numerical value specific to the shape of the vortex body in the range where the Reynolds number is 10 ³ to 10 ⁵ . Further, d _1, d _{2 and} d are representative lengths (projection lengths) of the respective vortex bodies.

The Karman vortex generated from the first vortex generator 13 propagates in the pressure conduit 23 as fluid vibration and is transmitted to the chamber 21. The pressure vibration in the chamber 21 is detected by the piezoelectric microphone 19, and the fluid vibration of the Karman vortex is converted into a voltage. As shown in FIG. 5B, the signal exchanged with the voltage is input to the amplifier 31 of the circuit unit 30,
It is amplified as shown in (c). The amplified signal is input to the comparator 32 and is detected by comparison as shown in FIG. The signal that has become a digital value is noise-removed by the filter 331 in the CPU 30.
The signal has no noise as shown in (e). The frequency F of this signal corresponding to the frequency is converted into a voltage value corresponding to the frequency as shown in FIG. 5 (f) by the F / V conversion 332 in the CPU 30, and the wind speed calculation 333 in the CPU 30 shows it by the following equation. Outputs the wind speed by calculation.

[0019]

[Equation 2] Here, St ₁ is the Strouhal number of the first vortex body 13, d
₁ is the representative length of the first vortex body 13 (St _1, d ₁ are known values). Since the first vortex body 13 has a cylindrical shape, the representative length does not change depending on the direction (wind direction). A voltage value indicating the F / V converted frequency is substituted for f ₁ .
Therefore, only the wind speed can be obtained without being affected by the wind direction.

On the other hand, the vortex generation frequency f ₂ of the Karman vortex generated from the second vortex forming body 14 is a shape in which the representative length is changed depending on the direction (wind direction) of the second vortex forming body 14, As shown in, changes depending on the wind speed v and the wind direction θ.

[0021]

[Equation 3] Here, St ₂ is the Strouhal number of the second vortex body 14, d
₂ (θ) is the representative length of the second vortex body 14. (St
₍₂ is a known value) If the fluid vibration of the Karman vortex generated from the second vortex body 14 is guided to the microphone 20 through the pressure conduit 24 and the vortex generation frequency f ₂ is detected, the vortex generation frequency f ₂ is obtained as shown in FIG. _{With 2} , it is possible to obtain a characteristic that changes depending on the wind speed v and the wind direction θ.

FIG. 4 shows the results when a flat plate having a width of 10 mm is used as an example of a shape whose representative length changes depending on the orientation. By the way, by dividing the frequency f ₂ and the previously detected frequency f ₁ based on the above equations 2 and 3, the wind direction θ can be calculated as in the following equation.

[0023]

[Equation 4] As can be seen from Equation 4 above, the wind direction θ does not depend on the wind speed v. As an example, when a flat plate with a width d ₂ is used, the representative length d ₂ (θ) is d ₂ (θ) = d ₂ cos θ, so the wind direction θ can be obtained from the following equation.

[0024]

[Equation 5] The wind speed and the wind direction calculated as described above are displayed on the display unit 50 as shown in FIG. 6, so that the driver can be informed of the state of the running wind, and the unstable running factors such as side wind disturbance can be detected. It becomes possible to grasp.

Further, since the present sensor section 10 detects the wind direction and the wind speed by detecting the generation frequency of the Karman vortex and converting it into a digital signal, there is no deterioration in accuracy. Further, as can be seen from Equation 1, since the detection can be performed without being affected by the temperature, the pressure, and the humidity, there is an effect that an error hardly occurs.

Further, since the sensor section 10 itself has no movable section,
Due to its simple structure, it is characterized by strong weather resistance.
In the above embodiment shown in FIGS. 1 and 2, the sensor unit 10 has a hierarchical structure.
Does not have to be arranged vertically, and may be provided adjacent to each other in the left-right direction or provided separately so long as the Karman vortices generated by the vortex generators 13 and 14 do not interfere with each other.

In the above embodiment shown in FIGS. 1 and 2, the means for detecting the Karman vortex are piezoelectric microphones 19 and 2 as means for detecting the fluid vibration of the Karman vortex.
Although 0 is used, detection by ultrasonic waves or detection by heat rays may be used.

The rectifying grid may be any wire mesh, honeycomb commutator or any other element that promotes the generation of Karman vortices generated from the vortex generators 13 and 14. Further, the second vortex body 14 is not limited to a flat plate and may have a shape in which the representative length (projection length) changes depending on the direction.

Further, as an example of use of the wind direction and wind speed detecting device, not only the wind speed and wind direction are displayed on the display unit 50 as shown in FIG. 6, but also steering for controlling a spoiler for rectification and steering force control. It can also be used as a sensor for controlling the Further, it can be used not only as a vehicle but also as a weather data sensor.

[0030]

As described above, according to the wind direction / velocity detector of the present invention, the first vortex body having a cylindrical shape and the second vortex body having a representative length that changes depending on the wind direction are provided. The frequency of the Karman vortex generated from each vortex body can be detected, and the wind direction and wind speed can be calculated from each frequency.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a wind direction and wind speed detection device of the present invention.

FIG. 2 is a vertical sectional view of FIG.

FIG. 3 is a system diagram showing a wind direction and wind speed detection device of the present invention.

FIG. 4 is a diagram showing a relationship between a wind direction and a vortex generation frequency generated by a second vortex body.

FIG. 5A is a diagram showing a configuration of a circuit unit.
(B)-(f) is a figure which shows the state of a signal.

FIG. 6 is a diagram showing an example of an attachment diagram when the device is attached to a vehicle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Sensor part 13 1st vortex body 14 2nd vortex body 19,20 Microphone 21,22 Chamber 23,24 Pressure conduit 30 Circuit part 31 Amplifier 32 Comparator 33 CPU 50 Display part

Claims (1)

[Claims] 1. A wind direction and wind speed detection device for detecting the wind direction and speed of a fluid to be measured, the first vortex body having a cylindrical outer shape, and a projection width projected by the fluid to be measured. A second vortex forming body having a shape whose length changes depending on the wind direction of the fluid to be measured, and a first detecting means for detecting the frequency of the Karman vortex generated downstream of the first vortex forming body, Second detecting means for detecting the frequency of the Karman vortex generated on the downstream side of the second vortex forming body, and first calculating means for calculating the wind speed based on the frequency detected by the first detecting means. The frequency detected by the first detection means and the second
A wind direction wind speed detecting device comprising: a second calculation means for calculating the wind direction based on the frequency detected by the detection means of.