JP3817610B2 - Ultrasonic air data sensor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ultrasonic air data sensor that measures airspeed and wind direction, wind speed, and temperature, and relates to a method particularly suitable for low-speed aircraft in airspeed measurement. Note that the airspeed represents the moving direction and speed of a three-dimensional object relative to the airflow, and the responsiveness of the airspeed measurement is not so important in the measurement for maneuvering, but the airspeed was used. Responsiveness is important for measuring turbulence. In this specification, a low speed aircraft means a short-range take-off and landing aircraft, a vertical take-off and landing aircraft, a rotary wing aircraft, a glider, an airship, a balloon, and the like.
[0002]
[Prior art]
Normally, the Pitot tube used in aircraft measures the total pressure and static pressure of air and determines the airspeed from the dynamic pressure of the difference. The airflow direction is measured by an arrow blade or the like. . By the way, since the dynamic pressure measured by the Pitot tube is proportional to the square of the airspeed, the measurement error becomes large at low speed, and the Pitot pipe is suitable for speed measurement in the low speed range. Absent. The pitot tube can be used usually in an area of 30 to 40 m / s or more. If the speed is lower than that, or if the airflow direction is significantly different from the body axis, the speed measurement itself becomes impossible. And since the arrow blade for measuring an airflow direction has a movable part, the fall of the responsiveness by the mass of an arrow blade and a vibration become a problem. Therefore, a general aircraft equipped with a Pito pipe as an airspeed sensor has a large measurement error or cannot measure the airspeed measurement value in the low speed range. Since the Pitot tube cannot measure airflow in the low speed region as described above, it is naturally not suitable as an anemometer for weather observation.
[0003]
On the other hand, the ultrasonic anemometer used for weather observation uses the fact that the propagation time of the ultrasonic wave propagating in a certain section changes due to the influence of the wind. A plurality of (generally, many) ultrasonic transmitters / receivers arranged can measure winds in all directions on a plane. For example, Patent Document 1 corresponds to this. However, due to aerodynamic interference between ultrasonic transmitters / receivers, it is difficult to measure in strong winds, 20 m / s or less for large-sized devices that can be mounted on aircraft, and 60 m / s or less for large equipment for ground installation. This is a possible area. In this measurable region, the measurement range on the high speed side is not sufficient for use in an aircraft, and an ultrasonic anemometer for weather observation is not suitable for an airspeed measuring instrument mounted on an aircraft. Even when an ultrasonic anemometer is used for weather observation, the airflow is affected by aerodynamic interference between the ultrasonic transmitters and receivers, and in particular causes a deterioration in measurement accuracy of the wind direction.
[0004]
The most common windmill-type anemometer for weather observation has a moving part and a large mass.Therefore, when it is installed on an aircraft boom as an airspeed indicator, the rigidity of the boom is avoided. Must be high. The boom needs to be long in order to make it less susceptible to airflow disturbance by the aircraft itself, and it is difficult to increase the rigidity. The responsiveness of airflow measurement is not so good, so it is not suitable for an airspeed measuring instrument mounted on an aircraft. When used for weather observation, it is very practical, but it is necessary to manufacture propellers and tails with high precision in order to measure with high accuracy. It is difficult to reduce manufacturing costs. Moreover, although it is not a problem in normal weather observation, it is difficult to measure the up-and-down wind for special applications and to measure the wind direction and wind speed in the extremely weak wind.
[0005]
An aircraft air-speed sensor (Patent Document 2), which has been previously developed by the present inventor and has already filed a patent application, is for solving the above-mentioned drawbacks of the conventional device, and is mounted on a low-speed aircraft. It can be used for low speed flight. However, the air speed sensor increases the measurement noise component in the air speed range of 50 m / s or more, and may not be able to measure even at a lower speed depending on the airflow angle. The cause of the former is that an ultrasonic transmitter / receiver is attached to be inclined with respect to the surface of the support portion, so that a step is formed between the surface of the ultrasonic transmitter / receiver and the support portion, and the structure has a high speed. In the area, it was found that the noise was generated by the disturbance of the airflow. In addition, the latter cause is that, due to the positional relationship between the support parts, there is an airflow angle where a part of the ultrasonic transceiver enters the wake region of the upstream ultrasonic transceiver support part, and the downstream side It was found to be the effect of turbulent flow on the ultrasonic transceiver.
[0006]
[Patent Document 1]
Japanese Patent Laid-Open No. 5-308787 “Ultrasonic Wind Direction Wind Speed Temperature Measuring Device”
Released on November 19, 1993
[Patent Document 2]
Japanese Laid-Open Patent Publication No. 2001-278196 “Aircraft Ultrasonic Airspeed Sensor”
Released on October 10, 2001
[0007]
[Problems to be solved by the invention]
An object of the present invention is to solve the above-mentioned problems, that is, an airspeed measurement device for an aircraft that can measure from a low speed region to a relatively high speed region, and can cope with a wide airflow angle, and a high An object of the present invention is to provide an ultrasonic air data sensor / probe that does not require moving parts and does not require moving parts that can realize a wind direction / air temperature / temperature measuring device for weather observation that does not require parts that require manufacturing accuracy.
[0008]
[Means for Solving the Problems]
  In order to reduce the occurrence of turbulence and increase measurement stability, the ultrasonic air data sensor of the present invention has a shape in which the transmitting / receiving surface of the ultrasonic transmitter / receiver is smoothly continuous with the surface of the support portion and has no irregularities. In addition, the support portions are arranged at the front and rear with respect to the main wind speed direction. In addition, a plurality of opposing ultrasonic transmitters / receivers are arranged and combined with different propagation path directions, the number of which is more redundant than the minimum required, and the arrangement wind speed is increased. By providing redundancy in the combination of ultrasonic transceivers for calculation, it is possible to calculate the wind speed without using the signal that is most strongly affected by internal and external noise, or the signal from a failed ultrasonic transceiver. I made it.
  The ultrasonic air data sensor of the present inventionWhen mounted on an aircraft as an airspeed meter, a support rod for fixing the ultrasonic transceiver is not attached to the base so that the ultrasonic transceiver support does not fall off even if the joint between the support rod and the base is broken. The structure is made to penetrate.
  A pair of ultrasonic propagation paths is formed between the ultrasonic transmitter / receiver installed on the base and the ultrasonic transmitter / receiver arranged concentrically around the base.Of the present inventionIn order to reduce the influence of the wake of the substrate, the ultrasonic air data sensor installed on the ground is installed at a position lower than the ultrasonic transmitter / receiver installed on the substrate.
  Using the ultrasonic air data sensor of the present inventionThe wide-area meteorological observation system has a large number of ground installations in which a pair of ultrasonic propagation paths is formed between an ultrasonic transmitter / receiver installed on a base and an ultrasonic transmitter / receiver arranged concentrically around the base. The ultrasonic air data sensor was connected to the meteorological data management center via a public communication line, and the terminals in each region were connected to the meteorological data management center via a public communication line.
  Using the ultrasonic air data sensor of the present inventionAn aircraft measurement system includes an ultrasonic air data sensor, an atmospheric pressure sensor, and means for correcting and calculating an equivalent airspeed from a true airspeed in order to obtain the same equivalent airspeed measurement value as a Pitot tube. .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a diagram showing the principle of an ultrasonic anemometer. When the ultrasonic wave propagates in the air, when the ultrasonic wave propagates in the forward direction with the wind, the propagation speed is increased by the wind speed, and when the ultrasonic wave is in the reverse direction, the propagation speed is decreased by the wind speed. Therefore, the relationship between the propagation time of the ultrasonic wave and the wind speed, which is obtained by dividing the distance by the velocity, is as follows.
W = D / 2 × (t₂-T₁) / (T₁Xt₂(1)
However,
W: Wind speed
D: Spacing between ultrasonic transceivers
t₁: Propagation time of ultrasonic waves forward to wind speed
t₂: Propagation time of ultrasonic waves in the direction opposite to the wind speed
At the same time, using the fact that the propagation speed of ultrasonic waves varies with the temperature, the temperature can be obtained by the following equation.
T = T₀× (a / a₀)²× (1 + W_v ²/ A²(2)
a = D / 2 × (t₁+ T₂) / (T₁Xt₂(3)
However,
T: temperature
T₀: Standard temperature
a: speed of sound
a₀: Speed of sound at standard temperature
W_v: Wind velocity component perpendicular to the ultrasonic wave propagation direction
[0010]
In order to measure the propagation time of ultrasonic waves, pulsed ultrasonic waves are transmitted from a transmitter / receiver, received by an opposing transmitter / receiver, and the timing thereof is measured. At this time, if the signal level at the time of reception decreases due to some influence such as airflow or noise, the head of the pulse signal cannot be recognized, and a measurement time delay corresponding to an integral multiple of the ultrasonic wavelength occurs. Sometimes. Even if a circuit that automatically increases the gain is provided, the noise level becomes relatively high, and this delay cannot be completely removed. Due to this delay, a large discontinuity occurs in the measurement signal. Therefore, the correct measurement value can be obtained by subtracting an integral multiple of τ obtained from the following equation from the propagation time measurement value according to the size of the discontinuity. it can.
τ = 1 / f (4)
However,
τ: Time for one wavelength
f: Frequency of ultrasonic wave to be used
[0011]
The discontinuous amount changes according to the wind speed and can be estimated by the following equation. If a delay of one wavelength occurs in the received signal on the leeward side,
dW = WD−2 × [(t₂-T₁−τ) / {(t₁+ Τ) × t₂}] (5)
If there is a delay of one wavelength in the received signal on the windward side,
dW = WD−2 × [(t₂-T₁+ Τ) / {t₁× (t₂+ Τ)}] (6)
If there is a delay of one wavelength in both received signals,
dW = WD−2 × [(t₂-T₁) / {(T₁+ Τ) × (t₂+ Τ)}] (7)
However,
dW: Estimated discontinuity
W: Wind speed
D: Spacing between ultrasonic transceivers
t₁: Propagation time of ultrasonic waves forward to wind speed
t₂: Propagation time of ultrasonic waves in the direction opposite to the wind speed
τ: Time for one wavelength
[0012]
Set a threshold value for determining a discontinuous amount in advance, and when the measured value changes discontinuously, subtract an integer multiple of the separate discontinuous amount estimated value closest to the discontinuous amount from the measured value, The value is used as an accurate measurement value. In practice, the discontinuity of the measured value is most often only a delay of one wavelength, that is, one time the estimated value. The correction of the measurement value by the discontinuous amount estimation value is performed only when the reception level of the ultrasonic wave is lowered. This is because the same discontinuity occurs even when the normal state is restored from the illegal state.
When delays of the same number of wavelengths occur in both the upstream and downstream received signals, the amount of discontinuity is small, and in reality, a clear difference from normal measurement value fluctuations cannot be recognized. However, in general, the received signal on the leeward side is more susceptible to airflow disturbances, which is likely to cause overwhelming discontinuities, and the received signal on both the leeward and leeward side is delayed by the same number of wavelengths. It happens very rarely stochastically.
[0013]
Conventionally, since an ultrasonic anemometer for weather observation needs to detect wind speeds in all directions with equal accuracy, six ultrasonic transmitters / receivers are attached to six support rods, resulting in a complicated shape and aerodynamic disturbance. Flow and acoustic noise were likely to occur. However, in general, aircraft fly at high speeds in only one direction and the other directions cannot fly or fly at very low speeds. Therefore, it is not necessary for an airspeed sensor for an aircraft to measure airflows in all directions in the same way, and only a single direction can be measured in a relatively high speed region. Therefore, from the viewpoint of emphasizing the measurement of airflow in one direction, the arrangement of the ultrasonic transmitter / receiver necessary for the ultrasonic anemometer is devised, the overall shape of the device is simplified, and aerodynamic noise and airflow turbulence are reduced. I thought. In particular, if there is an object upstream of the ultrasonic transmitter / receiver, it is easy to be affected by the turbulence of the air flow. It is important not to do so. In Patent Document 2 “Ultrasonic Airspeed Sensor for Aircraft” which is the present invention of the present inventor, the above-mentioned object was achieved to some extent. Due to the inclined mounting, a step is formed between the surface of the ultrasonic transceiver and the separate support portion, and the airflow is disturbed and noise is generated in the high speed range. In the present invention, since the entire configuration is devised so that the transmission / reception axis of ultrasonic waves is perpendicular to the surface of the support part, the surface of the ultrasonic transmitter / receiver is smoothly connected to the surface of the support part, and the turbulence of the airflow Can now be minimized. This shape is also effective when used as an anemometer for weather observation.
[0014]
Regardless of how the arrangement of the ultrasonic transceivers is devised, there is always an airflow direction that is affected by the turbulence of the airflow when it corresponds to airflow in any direction. Therefore, in the present invention, redundancy is provided by arranging the combination of the ultrasonic transceivers more than the minimum required three sets, and utilization rate and measurement accuracy are improved by not using illegal data. I did it. This configuration also ensures a function that operates effectively even when a part of the ultrasonic transceiver fails.
[0015]
The basic principle of the present invention will be described with reference to FIGS. FIG. 2 shows a probe shape, in which A is a front view from the front and B is a side view. Four support rods 11, 12, 13, and 14 are implanted in the base 1 so that the shaft tip portions are parallel to each other and the shaft core is positioned at each vertex of the quadrilateral, and the tip portions are streamline-shaped and are ultrasonic. It is a transceiver support part. This probe shape considers that the flow velocity direction, which is the main detection component of the aircraft, from the viewpoint of ensuring the stability of ultrasonic measurement, prevents the turbulence in the airflow most with respect to the airflow that matches the axial direction from the front of the aircraft. And devised. When the present invention is applied to airspeed measurement of an aircraft, as described above, the flow direction is mainly a component from the front to the rear with respect to the airframe. Accordingly, in order to detect the component, the ultrasonic transmitter / receiver is required to be arranged in a different position in the front-rear direction, and the surface of the ultrasonic transmitter / receiver is a surface perpendicular to the X-axis in order to be installed according to the transmitter / receiver axis. Will be inclined. For this reason, after arranging the tip of the support rod in a streamline shape, the arrangement of the ultrasonic transmitter / receiver was considered so that the surface thereof and the surface of the ultrasonic transmitter / receiver were parallel and smoothly connected. Then, the flow velocity component of the fluid is measured as three-dimensional information based on propagation time information in which a plurality of propagation paths for transmitting and receiving ultrasonic waves are formed and the flow velocity component of the fluid is superimposed. Specifically, three sets of six ultrasonic transceivers of the conventional ultrasonic anemometer are set to four sets of eight, and the configuration as shown in FIG. It is fixed to the fuselage so that the axial directions of 12, 13, and 14 are directed to the front of the aircraft, and an ultrasonic transmitter / receiver is attached to the base 1 and the support rods 11, 12, 13, and 14 to form an ultrasonic transmission / reception path. I did it. Since the ultrasonic transmission / reception path is formed between the ultrasonic transmission / reception units arranged at different positions in the longitudinal direction of the aircraft, the flow velocity of the components in the longitudinal direction of the aircraft can be detected. Moreover, since the probe base 1 and the support rods 11, 12, 13, and 14 have the least resistance to the airflow in this direction, the flow state is stable and accurate measurement can be performed. As shown in FIG. 4, the support rods 11, 12, 13, and 14 have a slight opening angle toward the front, so that the length of the support rod can be shortened, thereby increasing the rigidity. And weight is reduced.
[0016]
When the present invention is applied to an anemometer for weather observation on the ground, it is used with the front when attached to an aircraft facing vertically upward. In this case, it is necessary to deal with airflow from all directions in the horizontal direction, but the shape according to the present invention is not necessarily suitable for airflow from all directions. However, in the case of meteorological observation, it is sufficient if a maximum wind speed of 60 m / s can be measured, and it is not necessary to measure an air flow as high as the airspeed of the aircraft. Furthermore, because of the redundancy described later, the signal from the ultrasonic transmitter / receiver on the leeward side is not used, so it is possible to measure the wind direction and wind speed with high accuracy by always using the optimal signal for the airflow in any direction. it can. In the case of weather observation on the ground, the weight limit is not as strict as that for aircraft mounting, so it can be made larger than that for aircraft mounting to improve strong wind measurement performance.
[0017]
With the arrangement configuration of the ultrasonic transmitter / receiver as described above, the three-dimensional air speed or wind direction / wind speed can be obtained. This arrangement places the highest priority on the flow velocity measurement in the direction indicated by the arrow. As shown in Fig. 3, the X-axis is defined in the longitudinal direction of the aircraft, the Y-axis is defined in the left-right direction, and the Z-axis orthogonal coordinate form is defined in the vertical direction, and the XYZ components of the airspeed are defined as Vx, Vy, and Vz. The velocity component Wn of the air flow in the ultrasonic wave propagation direction between each set of ultrasonic transceivers is expressed by the following equation.
W_n= Vxsinθn + (Vysinφn + Vzcosφn) × cosθn (8)
However,
Vx: X direction component of airspeed
Vy: Y direction component of airspeed
Vz: Z direction component of airspeed
W_n: Velocity component in the direction of the ultrasonic transmitter / receiver (path n)
θn: YZ plane and W_nThe angle between
φn: Z-axis and W in YZ plane_nThe angle between
Here, if the arrangement of each sensor is perpendicular as shown in FIG. 3, that is, φ1 is 90 degrees, φ2 is 180 degrees, and φ3 is 270 degrees,
W₁= Vxsinθ1 + Vycosθl (9)
W₂= Vxsinθ2-Vycosθ2 (10)
W₃= Vxsinθ3-Vycosθ3 (11)
And when θ1 = θ2 = θ3 = θ,
Vx = (W₁+ W₃) / 2sinθ (12)
Vy = (W₁-W₃) / 2cosθ (13)
Vz = (W₁+ W₃-2 x W₃) / 2cosθ (14)
Thus, the airspeed can be obtained by this arithmetic expression.
[0018]
Measured by subtracting an integral multiple of the discontinuity estimate closest to the amount of discontinuity when the velocity component of the airflow in the ultrasonic propagation direction obtained by each ultrasonic transceiver set changes discontinuously. The error can be reduced. Assuming that the integral multiple at that time is N, the value of N is 0 when normal measurement is performed, but the value increases in N when the measured value changes discontinuously due to airflow disturbance or failure. To do. By constantly monitoring the value of N of each ultrasonic transmitter / receiver set and not using the measured value of the ultrasonic transmitter / receiver set having the largest value of N, the airflow finally obtained by the above arithmetic expression is obtained. Speed reliability and measurement accuracy are improved.
[0019]
Furthermore, even when the measured value of the ultrasonic propagation time becomes 0 or exceeds the threshold value, the measured value of the corresponding ultrasonic transceiver set is not used. This is because such a state may be a failure of the ultrasonic transmitter / receiver, or a state incapable of measurement due to airflow disturbance or noise.
[0020]
When mounting an object exposed outside the aircraft, it is natural to confirm that the object has sufficient strength by strength calculation or strength test, but it is necessary to consider deterioration due to aging and corrosion. . In the present invention, since the support rods 11, 12, 13, and 14 are structured to penetrate the base body 1, the support rods should be removed if the joint between the base body and the support bar is broken by welding or the like. There is no worry of falling off even if it is shifted or rotated.
[0021]
The aircraft normally displays the equivalent airspeed obtained by the Pitot tube on the control instrument, and the pilot uses it to fly. This is because the influence of the airflow on the aircraft is related not only to the velocity of the airflow but also to the density of the atmosphere. Since the airspeed obtained by the ultrasonic sensor is the true airspeed, by combining with the atmospheric pressure sensor, the equivalent airspeed is calculated with the following correction formula, and the measured value equivalent to the conventional Pitot tube is obtained. A measurement system can be constructed.
VEAS = VTAS {P / (ρoRT)}^0.5 (15)
However,
VEAS: Equivalent airspeed
VTAS: True airspeed
P: Atmospheric pressure
R: Gas constant
T: Air temperature
ρo: Standard atmospheric density
[0022]
【Example】
Below, the example manufactured for the airspeed measurement in a rotorcraft is shown in FIG. 4, and a present Example is described. In a general rotorcraft, the airspeed in the forward direction is about 80 m / s at maximum, and the speed when flying in other directions, for example, up, down, left, and right, is extremely low. By applying the present invention, it is expected that the airspeed can be measured in almost the entire flight speed region of the rotorcraft. In this embodiment, the axes of the four support rods 11, 12, 13, and 14 are not parallel to the axis of the base 1, and have a slight opening angle β (10 degrees in this embodiment) equal to that shown in the figure. Have it attached. This is because the rotor blades receive high-speed conditions, that is, strong air currents only in the forward direction, so they must be structurally rigid and low in weight, and structurally disturb the airflow. Since the turbulence of the airflow occurs as a wake, the ultrasonic wave propagation path is not considered to have been considered. Incidentally, in this embodiment, the propagation path length between the ultrasonic transceivers is 50 mm, the θ angle is 20 degrees, and the wavelength of the ultrasonic waves used is 200 kHz. Further, an anti-icing heater for preventing icing is built in the base 1 and the tip of each support rod. In addition, since the ultrasonic waves flow toward the leeward side according to the airspeed of the airframe, the ultrasonic transmitters / receivers are not arranged linearly opposite to each other but are installed on the windward side toward the α angle as shown in FIG. I did it. As a result, the propagation path of the ultrasonic wave becomes a bow shape swelled to the windward side as shown in the figure. The transmission / reception surface of the ultrasonic transmitter / receiver is formed on a smooth continuous surface with the surface of the support bar so as not to be uneven. Since the directivity of the ultrasonic transceiver used in this embodiment is 15 degrees on one side, if α is 10 degrees and the sound speed is 340 m / s, the ultrasonic wave is transmitted when the airspeed of the aircraft is 60 m / s. Transmission / reception is performed at the center point of the covered area, and a range from about 150 m / s forward to about 30 m / s backward is a measurement range based on directivity.
[0023]
FIG. 5 shows the estimated discontinuous change amount of the measured value. Since the maximum speed of a rotary wing machine is usually 70 m / s or less, the ultrasonic path direction airflow component is unlikely to exceed 30 m / s. Further, when delays of the same number of wavelengths occur in both the upwind and downwind received signals, the discontinuous amount is small as shown in the figure, and thus a clear difference from the normal measurement value fluctuation cannot be recognized. Taking these into consideration, the threshold value for determining the discontinuous amount is set to ± 3 m / s, and when the measured value changes discontinuously beyond ± 3 m / s, the discontinuity closest to the discontinuous amount is set. Subtract an integral multiple of the continuous quantity estimate from the measurement and use that value as the exact measurement. In practice, the discontinuity of the measured value is most often only a delay of one wavelength, that is, one time the estimated value. Note that the data update cycle is 50 milliseconds, and it is not considered as a normal physical phenomenon that a flow rate change of ± 3 m / s or more actually occurs during this period. Absent.
[0024]
FIG. 6 shows an example in which the sensor according to the present embodiment is installed on the rotorcraft. The rotary wing machine has a phenomenon that the forward speed is remarkably large in the other direction and the main rotor R is blown down. Therefore, in order to avoid the influence in airspeed measurement, the support rods 11 and 12 are attached to the end of the long rod-shaped base body 1 that coincides with the forward direction of the machine body so that the sensor S is positioned in front of the front end of the main rotor R. , 13, and 14 are mounted. Note that the airspeed measured by the ultrasonic anemometer is the true airspeed, but by mounting the barometer B at the same time and correcting it with the measured value, it is similar to the Pitot tube used in ordinary aircraft. Equivalent airspeed can be obtained.
[0025]
FIG. 7 shows an example in which the present invention is applied to a ground anemometer for weather observation. There is no problem with the same configuration as that for a rotary wing machine, but when there is no need to measure the airflow in the vertical direction, the number of support rods is three as shown in the figure, and the axis of the support rod when viewed from above is triangular. Plant so that it is located at each vertex. The ultrasonic transmitter / receiver attached to the base 1 and the ultrasonic transmitter / receiver attached to the support rods 11, 12, 13 are arranged at positions shifted in the vertical direction as shown in the figure, so that the turbulence of the air flow based on the wake is generated. The influence of can be reduced. In the case of installation on the ground, the risk of dropping the support bar is not as high as when it is mounted, so there is little need to penetrate the support bar through the base. The measurement of the air temperature is obtained by measuring the propagation time of the ultrasonic wave that reciprocates between constant and known ultrasonic wave propagation paths, and the air temperature can be directly measured, so that the 100-leaf box is unnecessary. The system which measures a wind direction wind speed and temperature by the above is comprised.
[0026]
Ultrasonic anemometers are used in places where maintenance is difficult, such as in tunnels, because they have few failures and do not require regular maintenance. FIG. 8 shows an application example to a wide-area meteorological observation system in which a large number of ultrasonic air data sensors according to the present invention are connected by a public communication line, taking advantage of this advantage. Many observation points including unmanned observation points that are difficult to maintain are located in various locations, and ultrasonic air data sensors are installed at each observation point, and connected to a weather data management center via a public communication line. An administrator server system is installed in the center to provide a center function, and users at various locations are equipped with terminals that can receive and analyze data. Users can receive observation data including not only the sensors installed on their terminals but also data from other regions, and they can perform analysis processing by installing common software. It can also be done with a terminal. The administrator manages the server for communication and monitors the failure of the sensor. The signal processor does not need to calculate the wind direction, wind speed, temperature, and simply sends a measurement signal to the public communication line. The calculation is performed by a user installing software operating on a general-purpose computer in his / her analysis system. This reduces the hardware cost of the signal processor and makes it easier to cope with software improvements.
[0027]
【The invention's effect】
  The ultrasonic air data sensor of the present invention is a combination of a plurality of opposing ultrasonic transmitters / receivers arranged in different directions of propagation paths, and the transmission / reception surfaces of the ultrasonic transmitters / receivers support it. Smooth and continuous surface with no irregularitiesAs a result, it is possible to improve the structural defect that airflow is disturbed and noise is generated in the high speed range of conventional devices,Increased measurement stability.
[0028]
  The ultrasonic air data sensor of the present invention is a combination of a plurality of opposing ultrasonic transmitters / receivers arranged in different directions of propagation paths, with respect to the main wind speed direction. The support part is arranged in the front and rear directionBy adopting it, it was possible to solve the problem that measurement could not be performed even in an air velocity range of 50 m / s or less depending on the airflow angle, and the generation of turbulence could be reduced and the measurement stability improved.
[0029]
The ultrasonic air data sensor of the present invention is a combination of a plurality of opposed ultrasonic transmitters / receivers arranged in different directions of propagation paths, and the number is more than the minimum necessary number. The influence of the wake generated by the device itself by adopting a configuration with wind speed vector calculation means that is arranged with redundancy and does not use the measurement value of the ultrasonic transmitter / receiver on the leeward side based on the detected wind direction information The accuracy of measurement is improved by excluding the detection value of the ultrasonic transceiver. In addition, when the measurement value of the error estimation value is not used as a criterion for not using the measurement value of the leeward ultrasonic transmitter / receiver, the detection value of the ultrasonic transmitter / receiver can be effectively captured when there is no influence.
[0030]
A plurality of opposing ultrasonic transmitters / receivers are arranged and combined with different directions of propagation paths, and the number of the ultrasonic transmitters / receivers is arranged with redundancy more than the minimum necessary number. The ultrasonic air data sensor according to the present invention adopting a configuration including means for detecting that the ultrasonic transceiver is in a failure state or incapable of measurement is a state in which a part of the ultrasonic transmitter / receiver is in a failure state or incapable measurement state. In this case, the measurement can be performed stably by excluding the detection value of the ultrasonic transceiver and measuring the wind speed.
[0031]
A pair of ultrasonic propagation paths is formed between an ultrasonic transmitter / receiver installed on a base and an ultrasonic transmitter / receiver arranged concentrically around the base, and a support for fixing the ultrasonic transmitter / receiver In the ultrasonic air data sensor of the present invention having a structure in which a rod is passed through the base, the ultrasonic transceiver support portion does not fall off even if the joint between the support rod and the base is broken.
[0032]
In the ground installation in which a pair of ultrasonic wave propagation paths is formed between the ultrasonic transmitter / receiver installed on the base and the ultrasonic transmitter / receiver arranged concentrically around the base, the concentrically arranged The ultrasonic air data sensor according to the present invention adopting a configuration in which the ultrasonic transmitter / receiver is attached to a position lower than the ultrasonic transmitter / receiver installed on the base is more sensitive than the conventional ultrasonic anemometer for weather observation. Since it is not easily affected by the turbulence of the airflow generated by the support rod, it is highly accurate for airflow in all directions, and the measurement capability in strong winds is improved. In addition, this sensor has no moving parts, and can perform highly accurate measurement as an ultrasonic anemometer that does not require high manufacturing accuracy. In addition, the temperature can be measured at the same time, and the entire observation system can be downsized because no hundreds of boxes are needed.
[0033]
A large number of ultrasonic air data sensors for ground installation in which a pair of ultrasonic propagation paths are formed between the ultrasonic transmitter / receiver installed on the base and the ultrasonic transmitter / receiver arranged concentrically around the base Is connected to a weather data management center via a public communication line, and a wide-area weather observation system in which terminals in various locations are connected to a weather data management center via a public communication line does not require extensive hardware, and does not require extensive hardware conditions. Can be collected easily, and weather information of each place processed by the center can be easily used at each terminal.
[0034]
An aircraft measurement system according to the present invention comprising an ultrasonic air data sensor according to the present invention, an atmospheric pressure sensor, and a means for correcting and calculating an equivalent airspeed from a true airspeed is equivalent to the same equivalent pair as a Pitot tube. It is possible to obtain an air velocity measurement value, and as a result, the speed display during low-speed flight becomes more accurate than before, and the flight safety of the aircraft can be improved.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating the principle of a general ultrasonic anemometer.
FIG. 2 is a shape of an air data sensor probe according to the present invention embodied for an aircraft, wherein A is a front view from the front, and B is a side view.
FIG. 3 is a diagram showing the principle of airflow measurement by an air data sensor according to the present invention.
FIG. 4 is a diagram showing an embodiment in which an air data sensor according to the present invention is embodied for a rotating machine.
FIG. 5 is a diagram showing a discontinuous change amount estimation value of a measured value of an air data sensor according to the present invention.
FIG. 6 is a view showing an example in which an air data sensor according to the present invention is installed and mounted for a rotorcraft.
FIG. 7 shows a shape of an air data sensor probe according to the present invention embodied for weather observation, wherein A is a view from above and B is a side view.
FIG. 8 is a diagram showing an example in which an air data sensor according to the present invention is applied to a wide-area weather observation system.
[Explanation of symbols]
W wind speed
D Ultrasonic propagation distance
V Airspeed
a Sound speed
R main rotor
B Barometer
S Sensor probe
1 Base
11,12,13,14 Support rod

Claims (9)

  A pair of opposing ultrasonic transmitters / receivers are arranged and combined with different directions of propagation paths, and the transmitting / receiving surfaces of the ultrasonic transmitters / receivers are smoothly and continuously connected to the surface of the support portion. An ultrasonic air data sensor characterized in that it has a non-existent shape and the support portions are arranged forward and backward with respect to the main wind speed direction to reduce the generation of turbulent flow and improve measurement stability. The number of paired ultrasonic transmitters / receivers is arranged with redundancy more than the minimum required number, and the detected air data of the ultrasonic transmitter / receiver on the leeward side is adopted. 2. The ultrasonic air data according to claim 1, further comprising: a wind velocity vector calculating unit that eliminates detection values affected by a wake generated by the apparatus itself to improve measurement accuracy. Sensor. The ultrasonic air data sensor according to claim 2, wherein the magnitude of the error estimation value is adopted as a criterion for not using the measurement value of the leeward ultrasonic transceiver. Means for detecting that the ultrasonic transceiver has failed or has become incapable of measurement, and when a part of the ultrasonic transceiver has failed or has been unable to be measured, the detected value of the ultrasonic transceiver is obtained. 3. The ultrasonic air data sensor according to claim 2 , wherein the wind speed is excluded and measured. The ultrasonic air data sensor according to claim 4 , wherein the measurement value of the ultrasonic propagation time is 0 or exceeds a threshold value by using a failure or an unmeasurable state as a criterion. A pair of ultrasonic propagation paths is formed between an ultrasonic transmitter / receiver installed on a base and an ultrasonic transmitter / receiver arranged concentrically around the base, and a support for fixing the ultrasonic transmitter / receiver 6. The ultrasonic transmitter / receiver support part does not fall off even if the joint portion between the support bar and the base member is broken by adopting a structure in which a rod is passed through the base member . The ultrasonic air data sensor described in 1. In the ground-installed one in which a pair of ultrasonic propagation paths is formed between the ultrasonic transmitter / receiver installed on the base and the ultrasonic transmitter / receiver arranged concentrically around the base, the concentric arrangement by the ultrasonic transceivers attached at a position lower than the ultrasonic transceiver installed in the base body according to any one of claims 1 to 5, characterized in that to reduce the effects of after base stream Ultrasonic air data sensor. A wide-area meteorological observation system in which a number of ultrasonic air data sensors according to claim 7 are connected to a meteorological data management center via a public communication line, and terminals in various locations are connected to the meteorological data management center via a public communication line. . An ultrasonic air data sensor according to any one of claims 1 to 5, an atmospheric pressure sensor, and means for correcting and calculating an equivalent air speed from a true air speed, thereby providing the same equivalent pair as a Pitot tube. An aircraft measurement system characterized by obtaining an air velocity measurement value.

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