JP7311149B2 - rotorcraft - Google Patents

Description

The present invention relates to rotorcraft.

Rotorcraft having multiple rotor blades are used in various fields. Such rotary wing aircraft, which are also called multicopters or drones, acquire altitude information using, for example, an air pressure sensor, enabling precise flight control. For example, Patent Literature 1 discloses a technique that includes means for adjusting altitude measurement values of a drone using an air pressure sensor, an attitude measurement sensor, and a relative wind speed sensor.

JP 2017-178301 A

However, as the fuselage of the rotary wing aircraft becomes smaller, the atmospheric pressure sensor is more susceptible to the influence of the air currents caused by the rotary wing. This tends to affect the estimation accuracy of the altitude of the rotorcraft by the air pressure sensor, making it difficult to control the rotorcraft.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a rotary-wing aircraft capable of maintaining or improving the estimation accuracy of the altitude of a downsized rotary-wing aircraft.

The main invention of the present invention for solving the above-mentioned problems is a rotary wing aircraft, comprising: a main body constituting a fuselage of the rotary wing aircraft; rotary wings supported by the main body; an air pressure sensor supported by a portion and including an air introduction hole; an elongated hollow member having an opening at one end connected to the air introduction hole and an opening at the other end open; Prepare.

Other problems disclosed by the present application and solutions thereof will be clarified by the section of the embodiment of the invention and the drawings.

According to the present invention, it is possible to maintain or improve the accuracy of estimating the altitude of a downsized rotorcraft.

1 is a perspective view showing the configuration of a rotorcraft 1 according to an embodiment of the present invention; FIG. It is a schematic diagram which shows the hollow member 6 which concerns on the same embodiment, and the structure of the circumference|surroundings. . It is a figure for demonstrating an example of the effect|action by the hollow member 6 which concerns on the same embodiment. It is a figure for demonstrating an example of the effect|action by the hollow member 6 which concerns on the same embodiment. FIG. 10 is a diagram showing a configuration of a hollow member 6' according to a modified example of the same embodiment; 5 is a graph showing changes in measured altitude with respect to flight time according to an example and a comparative example according to one embodiment of the present invention;

The contents of the embodiments of the present invention are listed and explained. An aircraft according to an embodiment of the present invention has the following configuration.

[Item 1]
a rotorcraft,
a main body that constitutes the airframe of the rotorcraft;
a rotary blade supported by the main body;
an atmospheric pressure sensor supported by a portion of the main body and provided with an atmosphere introduction hole;
an elongated hollow member having an opening at one end connected to the atmosphere introduction hole and an opening at the other end open;
A rotorcraft with a
[Item 2]
The rotorcraft according to item 1,
The main body is
a support frame for supporting a flight controller and/or battery for controlling flight of the rotorcraft;
an auxiliary frame connected to the support frame and including an arm that supports the rotor;
is composed of
The rotary wing aircraft, wherein the atmospheric pressure sensor is supported by the auxiliary frame.
[Item 3]
The rotorcraft according to item 1 or 2,
The rotorcraft, wherein the opening at the other end faces upward when the main body is placed horizontally.
[Item 4]
The rotorcraft according to any one of items 1 to 3,
A rotary wing aircraft, wherein there is at least one location in the longitudinal direction of the hollow member in which the inner diameter of the hollow member is larger than the inner diameter of the opening at the one end.

<Details of Embodiment>
A rotorcraft 1 according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing the configuration of a rotorcraft 1 according to this embodiment. In this specification, the X-direction, Y-direction and Z-direction shown in FIG.

As shown in FIG. 1 , a rotorcraft 1 according to this embodiment includes a main body 2 and rotor blades 3 . Note that the configuration of the rotorcraft 1 shown in FIG. 1 is an example, and a rotorcraft having a structure, shape, and size different from those of the main body 2 and the rotor blades 3 shown in FIG. 1 will be described below. Any rotary wing aircraft having a configuration corresponding to the main body 2 and the rotary wing 3 can be included in the scope of the present invention.

More specifically, the body portion 2 consists of a support frame 21 and an auxiliary frame 22 . Auxiliary frame 22 is connected to support frame 21 . Specifically, the auxiliary frame 22 is connected so as to extend from each of the support frames 21 in the front-rear direction. Such auxiliary frame 22 includes arms 23 . As shown in FIG. 1, the rotor blade 3 is supported by the arm 23. As shown in FIG. Note that the arm 23 according to this embodiment is also connected to the support frame 21 . The material constituting the body portion 2 is not particularly limited, and may be, for example, carbon fiber resin, glass fiber resin, magnesium, magnesium alloy, aluminum, aluminum alloy, steel, titanium, or other materials.

The support frame 21 loads and supports components related to flight control and power of the rotorcraft 1, such as a circuit board (not shown), a flight controller, or a battery. For example, the support frame 21 may be mounted with a control circuit including a flight controller. Electric power is supplied from the battery to the motor 20 and sensors, which will be described later, and the flight controller controls the number of revolutions of the motor 24 and the like.

The auxiliary frame 22 configures the body of the rotorcraft 1 , is connected to the support frame 21 , and supports the rotor blades 3 . In the example shown in FIG. 1, the auxiliary frame 22 extends in the front-rear direction from the end of the support frame 21 in the front-rear direction, and extends laterally in the width direction from the middle. The auxiliary frame 22 can function as a propeller guard for the rotor blades 3 . For example, the auxiliary frame 22 may protect the rotor 3 attached to the motor 4 and the motor 4 in the event of an aircraft collision.

A rotary blade 3 is provided between the end of the auxiliary frame 22 and the support frame 21 of the arm 23 . In the example shown in FIG. 1 , the arm 23 is provided with a motor mount 231 , the motor mount 231 is provided with the motor 4 that powers the rotor 3 , and the rotor 3 is attached to the motor 4 .

In this embodiment, the arms 23 and the rotor blades 3 are provided at four locations on the front, rear, left, and right, but the present invention is not limited to this example. Depending on the structure, shape, equipment, size, etc. of the rotorcraft 1, the number of arms 23 and rotor blades 3 provided may be changed as appropriate.

Further, a camera 30 for capturing an image from a first person view (FPV) may be provided on the support frame 21 at the connecting portion between the support frame 21 and the auxiliary frame 22 on the front side of the rotorcraft 1. . The camera 30 can be provided at any position on the support frame 21 other than the position shown in FIG.

Further, as shown in FIG. 1 , the rotary wing aircraft 1 according to this embodiment is provided with an air pressure sensor 5 on the auxiliary frame 22 . Such an atmospheric pressure sensor 5 is provided for estimating the altitude of the rotorcraft 1 . The atmospheric pressure data obtained by the atmospheric pressure sensor 5 is transmitted to a flight controller (not shown), and the altitude is estimated based on the atmospheric pressure data. Although the type of the atmospheric pressure sensor 5 is not particularly limited, for example, a piezoresistive atmospheric pressure sensor can be used.

The atmospheric pressure sensor 5 is provided with an air introduction hole 51 for introducing air. Air flows in or out between the inside and outside of the atmospheric pressure sensor 5 via the air introduction hole 51 . The barometric pressure sensor 5 detects a signal relating to pressure (ie barometric pressure) from the atmosphere, generates data relating to such barometric pressure, and sends such information to the flight controller.

Further, as shown in FIG. 1 , in the rotorcraft 1 according to the present embodiment, a hollow member 6 is provided above the atmospheric pressure sensor 5 . The hollow member 6 has an elongated shape and is open at both ends in the longitudinal direction.

FIG. 2 is a schematic diagram showing the configuration of the hollow member 6 and its surroundings according to this embodiment. As shown in FIG. 2 , the auxiliary frame 22 is provided with the atmospheric pressure sensor 5 , and the hollow member 6 is provided above the atmospheric pressure sensor 5 . The hollow member 6 is provided so that the air introduction hole 51 of the atmospheric pressure sensor 5 and the opening 61 of the hollow member 6 on the side where the atmospheric pressure sensor 5 is provided are connected. An opening 62 of the hollow member 6 opposite to the opening 61 faces upward.

3 and 4 are diagrams for explaining an example of the action of the hollow member 6 according to this embodiment. The example shown in FIG. 3 is an example in which the air pressure sensor 5 supported by the auxiliary frame 22 is provided with the hollow member 6 . The example shown in FIG. 4 is an example in which the air pressure sensor 5 supported by the auxiliary frame 22 is not provided with the hollow member 6 .

When the rotary wing aircraft 1 is to fly, the rotary wing 3 rotates and an air current is generated downward from above the rotary wing aircraft 1 . Then, an air flow (arrows in the figure) is generated around the rotor blades 3 . In the example shown in FIG. 4, the airflow generated by the rotor blades 3 passes right above the atmosphere introduction hole 51 or flows into the atmosphere introduction hole 51, thereby causing large fluctuations in atmospheric pressure. In particular, the generation of the air current pulls the air from the atmosphere introduction hole 51 and makes it easier to flow to the outside. As a result, the estimated atmospheric pressure is different from the atmospheric pressure corresponding to the actual altitude during flight, or the atmospheric pressure fluctuates greatly, making it difficult to uniquely estimate the altitude.

On the other hand, in the example shown in FIG. 3 , the air introduction hole 51 is connected to the opening 61 of the hollow member 6 , and air enters and exits through the opening 62 of the hollow member 6 . In this case, the atmospheric pressure sensor 5 substantially detects changes in pressure caused by air entering and exiting the opening 62 . Then, the influence of the airflow generated by the rotor blades 3 is not directly applied to the atmosphere introduction holes 51 . Therefore, fluctuations in atmospheric pressure are less likely to occur, and the actual atmospheric pressure can be detected with higher accuracy. Therefore, it becomes possible to estimate the altitude of the rotorcraft 1 in flight with higher accuracy.

It is preferable that the end portion 61a of the hollow member 6 on the side where the opening portion 61 is provided is in close contact with the atmospheric pressure sensor 5 or the auxiliary frame 22 that supports the atmospheric pressure sensor 5 . For example, the end portion 61a and the atmospheric pressure sensor 5 or the auxiliary frame 22 may be adhered to each other with an adhesive, a sealing member, or the like.

Also, the atmospheric pressure sensor 5 may be installed anywhere on the main body 2 . In this embodiment, the support frame 21 is provided with a flight controller and/or a heating element such as a battery. In order to reduce the thermal influence of these heating elements on the atmospheric pressure sensor 5 , the atmospheric pressure sensor 5 is preferably provided on the auxiliary frame 22 instead of the support frame 21 . Further, the atmospheric pressure sensor 5 does not necessarily have to be provided on the upper surface side of the body portion 2, and may be provided on the lower surface side, the side surface side, or the like.

Moreover, when the auxiliary frame 22 is composed of the arm 23 and other parts, the air pressure sensor 5 is preferably provided in the part other than the arm 23 . Since the rotor blades 3 are provided on the arm 23 , if the air pressure sensor 5 is further provided on the arm 23 , the air pressure sensor 5 is likely to be affected by the airflow generated by the rotation of the rotor blades 3 . Therefore, it is preferable that the atmospheric pressure sensor 5 be provided at a portion away from the rotor blade 3 (that is, at a portion other than the arm 23).

Moreover, the material of the hollow member 6 is not particularly limited. For example, the hollow member 6 may be made of rubber, plastic, resin, metal, ceramics, or the like. From the viewpoint of flight control of the rotorcraft 1, it is preferable to use a relatively lightweight material. Moreover, the thickness of the hollow member 6 is not particularly limited. From the viewpoint of flight control of the rotorcraft 1, the wall thickness is preferably relatively thin.

Moreover, the length in the longitudinal direction of the hollow member 6 is not particularly limited. The length can be appropriately set according to, for example, the influence of the airflow generated by the rotor blades 3, the controllability of the rotorcraft 1 during flight, and the like.

In addition, the hollow member 6 may be a flexible member as described above. In this case, the hollow member 6 does not necessarily have a shape extending along one direction, and may have a curved shape. For example, the hollow member 6 may be an L-shaped, U-shaped, S-shaped, or other member whose center axis follows an arbitrary curved line.

The direction in which the opening 62 of the hollow member 6 faces is not particularly limited, but like the opening 62 according to the present embodiment, the opening 62 faces upward when the main body 2 is placed horizontally. is preferred. During low-altitude flight, the air flowing downward from the rotor blades 3 collides with the ground and tends to blow back. At this time, for example, if the opening 62 faces downward, the blown back air tends to flow into the hollow member 6, so that the atmospheric pressure detected by the atmospheric pressure sensor 5 tends to fluctuate. Therefore, it is preferable that the opening 62 faces upward. The term “upward” here means a state in which the Z-direction component of the X-direction, Y-direction, and Z-direction components constituting the direction of the central axis of the opening 62 is positive upward.

Moreover, the size and shape of the cross section orthogonal to the longitudinal direction of the hollow member 6 are not particularly limited. It is sufficient if the opening area of the opening 61 of the hollow member 6 is equal to or larger than the opening area of the air introduction hole 51 of the atmospheric pressure sensor 5 .

Moreover, the cross-sectional shape of the hollow member 6 is not particularly limited. The cross-sectional shape of the hollow member 6 according to this embodiment is a circle (that is, the hollow member 6 is a cylindrical member), but it may be a rectangular tube cross-section. Moreover, the cross-sectional shape of the hollow member 6 may be a shape that changes in the longitudinal direction of the hollow member 6 . For example, the hollow member 6 may have at least one location in its longitudinal direction where the inner diameter of the hollow member 6 is larger than the inner diameter of the opening 61 .

FIG. 5 is a diagram showing the configuration of a hollow member 6' according to a modified example of this embodiment. As shown in FIG. 5 , the hollow member 6 ′ has a bulging portion 63 that bulges outward from the opening 61 . The inner diameter of the hollow member 6 ′ at the bulging portion 63 is larger than the inner diameter of the hollow member 6 ′ at the opening 61 . The configuration of other parts is the same as the configuration of the hollow member 6 shown in FIG.

In the hollow member 6' shown in FIG. In such a space, fluctuations in the flow of air flowing inside the middle section member 6' can be suppressed. As a result, fluctuations in the amount of air flowing through the atmosphere introduction hole 51 are reduced, so fluctuations in the atmospheric pressure detected by the atmospheric pressure sensor 5 are reduced. Therefore, noise in the estimation of the altitude of the rotorcraft 1 based on the atmospheric pressure sensor 5 is reduced, and the estimation accuracy of the altitude is improved.

Next, an example of the rotorcraft 1 according to this embodiment will be described.

The rotary wing aircraft 1 (example) provided with the hollow member 6 according to the above-described embodiment shown in FIGS. 1 and 2 and the rotary wing aircraft (comparative Example) were used to measure the altitude measured based on the barometric sensor for the time from takeoff to hovering at a given altitude for each. For comparison of accuracy, the altitude measured by the barometric sensor without using the rotorcraft was used as the true value. The length of the hollow member 6 was made substantially equal to the diameter of the rotor blade 3 .

FIG. 6 is a graph showing changes in measured altitude versus flight time according to the present embodiment and the comparative example. In the graph shown in FIG. 6, each rotorcraft is before takeoff from 0 to t1, rotates the rotor at t1 to start flight, then climbs to a predetermined height, and reaches a predetermined height at t2. and hovering at a predetermined height after t2.

As shown in the graph of FIG. 6, in the rotorcraft 1 according to the embodiment, although the measured value of the altitude drops due to the effect of blowback immediately after takeoff, it shows a value close to the true value after the start of flight. . On the other hand, the rotary wing aircraft according to the comparative example shows a large drop in the measured value of altitude due to blowback, and the value is significantly lower than the true value even after the start of flight.

From the above results, it can be seen that by providing the hollow member 6 so as to cover the atmosphere introduction hole 51, the atmospheric pressure sensor 5 is less susceptible to the influence of the airflow generated by the rotor blades. Therefore, it was shown that the air pressure sensor 5 can obtain a value closer to the actual altitude. As a result, the altitude can be estimated with higher accuracy, so the flight control of the rotorcraft 1 can be performed more accurately.

As described above, in the rotorcraft 1 according to the embodiment of the present invention, the air pressure sensor 5 can be It is possible to reduce the variation in atmospheric pressure detected by , and to measure altitude with higher accuracy. The configuration according to the present embodiment is more effective in flight control of a small rotorcraft 1 for photographing, inspection, etc. in a confined or narrow space. Such a rotary wing aircraft 1 realizes more accurate flight in radio control and autonomous flight.

Although the present embodiment has been described above, the above-described embodiment is intended to facilitate understanding of the present invention, and is not intended to limit and interpret the present invention. The present invention can be modified and improved without departing from its spirit, and the present invention also includes equivalents thereof.

REFERENCE SIGNS LIST 1 rotorcraft 2 main body 3 rotor 4 motor 5 atmospheric pressure sensor 6 hollow member 21 support frame 22 auxiliary frame 23 arm 51 atmosphere introduction hole 61, 62 opening

Claims (5)

a rotorcraft,
a main body that constitutes the airframe of the rotorcraft;
a rotary blade supported by the main body;
an atmospheric pressure sensor supported by a portion of the main body and provided with an atmosphere introduction hole;
a hollow member having an opening at one end connected to the atmosphere introduction hole and having an opening at the other end open;
with
The opening at the other end of the hollow member is provided at a position outside the center of the rotor blade when viewed from the center of the main body in a plan view, and the rotation to the left in the left-right direction of the fuselage. A rotorcraft , located between the wing and said rotor on the right . A rotorcraft according to claim 1,
The main body is
a support frame for supporting a flight controller and/or battery for controlling flight of the rotorcraft;
an auxiliary frame connected to the support frame and including an arm that supports the rotor;
is composed of
The rotary wing aircraft, wherein the atmospheric pressure sensor is supported by the auxiliary frame. A rotorcraft according to claim 1 or 2,
The rotorcraft, wherein the opening at the other end faces upward when the main body is placed horizontally. The rotorcraft according to any one of claims 1 to 3,
A rotary wing aircraft, wherein there is at least one location in the longitudinal direction of the hollow member in which the inner diameter of the hollow member is larger than the inner diameter of the opening at the one end. The rotorcraft according to any one of claims 1 to 4,
The rotary wing aircraft, wherein the atmospheric pressure sensor and the hollow member are positioned above a propeller that constitutes the rotary wing.

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