WO2017221387A1 - Unmanned aircraft and storage method therefor - Google Patents

Abstract

Provided is an unmanned aircraft with high space efficiency in storage, such that flight disturbances and noise caused by vibrations of rotors are minimized. To address this, the unmanned aircraft comprising a plurality of rotors which, by adjusting the rotational speeds thereof, control the attitude of the aircraft body and flight operations, is characterized in that at least one of the plurality of rotors is a single-blade rotor which has a single blade and a counterweight of the blade. Furthermore, a storage method for the unmanned aircraft is characterized by including a step wherein the position of the blades of each rotor are arranged so as to be directed toward the center of the aircraft body along the extension direction of arms that support the rotors.

Description

Unmanned aerial vehicles and their storage methods

The present invention relates to an unmanned aerial vehicle and a storage method thereof.

Conventionally, small unmanned aerial vehicles represented by industrial unmanned helicopters have been expensive and difficult to obtain and require skill to operate in order to fly stably. However, in recent years, improvements in sensors and software used for unmanned aerial vehicle attitude control and autonomous flight have made significant progress, and this has significantly improved the operability of unmanned aircraft and made it possible to obtain high-performance aircraft at low cost. . From such a background, the application of a small multi-copter to various missions in a wide range of fields is now being tried, not only for hobby purposes.

JP-T-2002-531313

Such a multicopter generally uses a rotor in which a plurality of blades are arranged at equal intervals in the circumferential direction. A rotor having a plurality of blades has a problem in that the output efficiency of the rotor is likely to decrease because each blade passes through turbulent air flow generated by the blade in the front in the rotation direction. In addition, the multicopter has a characteristic that the rotor tends to vibrate due to the mechanism of controlling the attitude and flight operation of the aircraft while continuously changing the rotational speed of each rotor. In addition, for example, when the rotor is blown upward, the rotating surface of the blade may tilt and the rotor may precess. Such vibrations cause disturbance in the flight operation of the aircraft and noise.

Also, such a multi-copter rotor is generally arranged at the tip of an arm that extends radially from the center of the fuselage. Therefore, when the rotor has a plurality of blades, the whole blade or a part thereof always protrudes outward from the arm regardless of the angular position of the blade. The protruding blades hinder the transportation of the airframe, and reduce the space efficiency of the airframe storage location.

In view of the above problems, the problem to be solved by the present invention is to provide an unmanned aerial vehicle that suppresses flight disturbance and noise caused by rotor vibration and has high space efficiency during storage.

In order to solve the above-described problem, an unmanned aerial vehicle according to the present invention is an unmanned aerial vehicle that includes a plurality of rotors and controls the attitude and flight operation of the fuselage by adjusting the rotation speed of each of the rotors. At least one of the above is a single rotor having a single blade, a blade composed of only one blade, and a counterweight of the blade. In addition, it is desirable that all of the plurality of rotors is the first rotor.

Since the first rotor of the present invention is composed of only one blade, unlike a general rotor having a plurality of blades, the output by passing through the turbulence generated by other blades. There is no need to consider a decrease in efficiency. Furthermore, the first rotor has a feature that acceleration / deceleration is quicker than the general rotor. Therefore, the stability and operability of the fuselage can be improved by adopting this first rotor in an unmanned aerial vehicle that controls the attitude and flight motion of the fuselage while continuously changing the rotational speed of each rotor. .

Further, the single rotor of the present invention has a counterweight which is a dedicated weight member for suppressing vibration accompanying the rotation of the blade. By using a balancer or the like and optimizing the position, size, and weight of the counterweight in advance, vibration generated by the first rotor can be suppressed. In addition, the first rotor has a feature that it is less likely to cause precession than a general rotor having a plurality of blades, and a synergistic effect on the vibration suppression of the rotor is expected. The unmanned aerial vehicle according to the present invention includes the first rotor so that it is possible to suppress flight disturbance and noise caused by the vibration of the rotor. It should be noted that the rotors of the unmanned aerial vehicle of the present invention are all preferably one-gear rotors. However, even when only a part of the first-gear rotors are employed, the same effect is recognized although limited.

Furthermore, since the single rotor of the present invention is composed of a single blade, the position of the blade of each single rotor is positioned along the extending direction of the arm on which the single rotor is supported. By arranging it toward the center of the space, it is possible to increase the space efficiency during storage of the aircraft.

Further, the position of the center of gravity of the counterweight is preferably higher than the position of the base end of the blade when the first rotor is stationary.

When the unmanned aircraft is flying, the blades are corned according to the centrifugal force and lift force acting on the blades. In other words, the center of gravity of the blade during rotation may move upward as compared to when the blade is stationary due to the blade load on the blade. For this reason, according to the weight of the aircraft, the weight of the transported object, etc., the center of gravity of the counterweight is positioned above the position of the blade when stationary, thereby improving the dynamic balance during unmanned aircraft flight. it can. Note that the optimum position of the counterweight above the blade can be adjusted by rotating the first rotor at the actual number of revolutions, or by using a dynamic balancer or the like.

Further, it is preferable that the first rotor further has a spinner that covers a base end portion of the blade, and the counterweight is accommodated in the spinner. The counterweight may be fixed to the inner peripheral surface of the spinner.

By accommodating the counter weight in the spinner, the air resistance of the counter weight can be suppressed, and since the counter weight does not protrude outside the spinner, the space efficiency during storage of the aircraft can be further increased. .

Further, it is preferable that the position of the center of gravity of the counterweight can be finely adjusted after the first rotor is mounted on the unmanned aircraft.

By making it possible to finely adjust the position of the center of gravity of the counterweight after installation on an unmanned aerial vehicle, it is possible to flexibly reduce the error between the theoretical balance to suppress the vibration of the first rotor and the balance when installed on the actual aircraft. It can be eliminated.

Further, each of the rotors may have an outer rotor type motor as a driving source, and the blade and the counterweight may be integrated with a motor case of the outer rotor type motor.

Because the blade and counterweight are integrated into the motor case of the outer rotor type motor, the number of rotor parts and assembly errors can be reduced. Thereby, it can suppress that the balance of a braid | blade and a counterweight is impaired by a cumulative tolerance. For example, when the counterweight is made of a material that affects the magnetic field lines, and when the counterweight is formed by thickening a part of the motor case in the circumferential direction, the amount of leakage magnetic flux to the outside of the motor case is small. By reducing, the output efficiency of the rotor can be improved.

Further, in order to solve the above-mentioned problems, the storage method for an unmanned aerial vehicle including a plurality of rotors according to the present invention is such that each rotor has a single blade and a counterweight of the blade. Each of the rotors is supported by a plurality of arms extending radially from the center of the unmanned aircraft body, and the position of the blade of each rotor is determined by the extension of the arm on which the rotor is supported. It includes a step of arranging the airframe toward the center side of the airframe along the outgoing direction.

In the unmanned aerial vehicle of the present invention, since the blades of each rotor are composed of a single piece, the position of the blades of each rotor is directed toward the center of the fuselage along the extending direction of the arm on which the rotor is supported. The space efficiency during storage of the aircraft can be improved.

As described above, according to the unmanned aerial vehicle and the unmanned aircraft storage method according to the present invention, it is possible to suppress the flight disturbance and noise caused by the vibration of the rotor, and to improve the space efficiency during the storage. .

It is a block diagram which shows the function structure of the multicopter concerning embodiment. It is a fragmentary perspective view which shows the structure of a rotor. It is a figure explaining the storage method of a multicopter. It is a figure which shows the 1st modification of a rotor. It is a figure which shows the 2nd modification of a rotor.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. This embodiment is an example of a multicopter 10 (quad copter) that is an unmanned aerial vehicle in which four rotors R are mounted at equal intervals in the circumferential direction of the airframe. The “rotor” in the present invention means a rotor having a vertical rotating shaft and a horizontal rotating surface, and does not include a rotor having a horizontal rotating shaft such as an airplane propeller. Further, in the present invention, “upper” for the rotor R means the intake side of the rotor R, that is, the rising direction of the multicopter 10, and “lower” means the exhaust side of the rotor R, that is, the lowering direction of the multicopter 10. I mean.

[overall structure]
FIG. 1 is a block diagram showing a functional configuration of the multicopter 10. The aircraft of the multicopter 10 includes a flight controller 20, four rotors R, an ESC 43 (Electric Speed Controller) that controls rotation of the rotors R, a wireless transceiver 33 that performs wireless communication with an operator's control terminal 60, and A battery 51 as a power supply source is mounted.

Each rotor R has a motor 41 which is an outer rotor type motor, a blade 42b connected to the output shaft thereof, and a counterweight 42w of the blade 42b. The ESC 43 is connected to the motor 41 of the rotor R and is a device that rotates the motor 41 at a speed instructed by the flight controller FC. The multicopter 11 in this embodiment is a quadcopter on which four rotors R are mounted. However, the number of rotors R is not limited to four, and required flight stability, allowable cost, etc. It can be appropriately changed depending on the situation.

The flight controller FC includes a control device 20 that is a microcontroller. The control device 20 includes a CPU 21 that is a central processing unit, a memory 22 that is a storage device such as a ROM and a RAM, and a PWM controller 23 that controls the rotation speed and rotation speed of each motor 41 via the ESC 43.

The flight controller FC further includes a flight control sensor group 31 and a GPS receiver 32 (hereinafter collectively referred to as “sensors”), which are connected to the control device 20. The flight control sensor group 31 of the multicopter 10 in this embodiment includes an acceleration sensor, an angular velocity sensor, an atmospheric pressure sensor (altitude sensor), a geomagnetic sensor (orientation sensor), and the like. The control device 20 can acquire position information of the own aircraft including the latitude and longitude of the flight, the flight altitude, and the azimuth angle of the nose, in addition to the tilt and rotation of the aircraft, using these sensors and the like.

The memory 22 of the control device 20 stores a flight control program FCP, which is a program in which a flight control algorithm for controlling the attitude and basic flight operation of the multicopter 10 during flight is installed. The flight control program FCP adjusts the number of rotations of each rotor R based on the current position acquired from a sensor or the like according to an instruction from the operator (control terminal 60), and corrects the attitude and position disturbance of the fuselage. Fly 10

The operation of the multicopter 10 can be performed by the operator from the control terminal 60. For example, parameters such as the flight path, speed, and altitude are registered in advance in the flight control program FCP, and autonomously reach the destination. It is also possible to fly (hereinafter referred to as “autopilot”).

Thus, the multicopter 10 in this embodiment has an advanced flight control function. However, the unmanned aerial vehicle according to the present invention may be any aircraft that includes a plurality of rotors R and controls the attitude and flight operation of the aircraft by adjusting the rotational speed of each of the rotors R. It may be an airframe in which sensors are omitted, or an airframe that does not have an autopilot function and can fly only by manual operation.

[Rotor configuration]
FIG. 2 is a partial perspective view showing the configuration of the rotor R of the multicopter 10. The multicopter 10 includes four rotors R, and all the rotors R have the same configuration as that in FIG. As shown in FIG. 2, the rotor R includes a motor 41 that is an outer rotor type motor, a single blade 42 b that is connected to the output shaft of the motor 41, and a dome-shaped spinner 46 that covers a connecting portion between the motor 41 and the blade 42 b. , And a counter-rotor composed of a counterweight 42w fixed to the inner peripheral surface of the spinner 46.

The counterweight 42w is a dedicated weight member for suppressing vibration accompanying the rotation of the blade 42b. The position of the center of gravity of the counterweight 42w of the present embodiment is disposed slightly above the position of the center of gravity when the blade 42b is stationary. During the flight of the multicopter 10, the blade 42b is corned by the centrifugal force and the lift force acting on the blade 42b. Since the center of gravity of the counterweight 42w is disposed above the position of the center of gravity when the blade 42b is stationary, the dynamic balance in this state can be improved. The specific position, shape, and weight of the counterweight 42w are optimized in advance by rotating the rotor R at an actual rotational speed or using a dynamic balancer or the like.

The rotor R of the present embodiment determines the position of the center of gravity of the counterweight 42w based on the actual shape, hardness, rotational speed, etc. of the blade 42b in consideration of dynamic balance. etc. If not strictly, as the rotor R ₂ in FIG. 5 to be described later, it is also conceivable to match the vertical center of gravity of the blade 42b and the counterweight 42w stationary.

Since the optimal position, shape, and weight of the counterweight 42w change due to slight differences in the properties of the blade 42b, it is necessary to readjust the balance each time the design of the blade 42b is changed. The counterweight 42w of this embodiment uses lead as its material, and when adjusting the balance between the counterweight 42w and the blade 42b, the shape and weight of the counterweight 42w can be easily finely adjusted. It is possible. The material of the counterweight of the present invention is not particularly limited, and materials other than lead can be used. However, in order to suppress the size of the counterweight 42w and prevent the counterweight 42w from protruding long in the radial direction of the rotor R, It is preferable to use a material having a large specific gravity.

The counterweight 42 w of the present embodiment is a separate member from the blade 42 b and is fixed to the inner peripheral surface of the spinner 46. Counterweight 42w, for example, as the rotor R ₂ in FIG. 5 to be described later, may be formed integrally continuous from the blade 42b, furthermore, a hub integral not shown connecting the motor 41 and the blade 42b It may be made.

Further, the counterweight 42w of the present embodiment is stuck to the inner peripheral surface of the spinner 46 and fixed at one place. The positional relationship between the blade 42b and the counterweight 42w is preferably adjusted before the rotor R is mounted on the multicopter 10, but the balance adjusted by the rotor R alone and the multicopter 10 are actually mounted. It is also conceivable that an error occurs in the balance when flying. In preparation for such a case, for example, the relative position and arrangement angle of the counterweight 42w with respect to the blade 42b can be finely adjusted later by the fixing position of the screw or the like for fixing the counterweight 42w and the degree of tightening or loosening thereof. By doing so, it is possible to flexibly eliminate the error between the theoretical balance and the actual balance.

In the multicopter 10 of this embodiment, since the rotor R is configured by one blade 42b, the reduction in output efficiency due to the blade 42b passing through the turbulence generated by the other blade is considered. There is no need. Furthermore, the first rotor has a feature that acceleration / deceleration is quicker than a general rotor having a plurality of blades. By adopting this rotor R in the multicopter 10 that controls the attitude and flight motion of the aircraft while continuously changing the rotational speed of each rotor, the stability and operation of the aircraft during the flight of the multicopter 10 are achieved. Sex has been improved.

Further, in the rotor R of the present embodiment, the counterweight 42w is accommodated inside the spinner 46. For example, as the rotor R ₂ in FIG. 5 to be described later, if the counterweight 42w is exposed to the outside, air resistance is generated in counterweight 42w by the blade 42b is rotated, the output efficiency of the rotor R ₂ is lowered It will be. In the rotor R of the present embodiment, since the counterweight 42w is accommodated inside the spinner 46, the reduction in output efficiency due to such air resistance is prevented. This feature also contributes to improving the stability and operability of the aircraft during the flight of the multicopter 10. Further, the counterweight 42 w of the present embodiment is fixed to the inner peripheral surface of the spinner 46. Therefore, even when the blade 42b rotates and a centrifugal force acts on the counterweight 42w, the counterweight 42w is pressed against the inner peripheral surface of the spinner 46, and the counterweight 42w is prevented from falling off due to the centrifugal force. The effect is also recognized.

Further, in the multicopter 10 of the present embodiment, the vibration generated by the blade 42b can be canceled by the counterweight 42w that is a weight member optimized for suppressing the vibration of the blade 42b. In addition, the first rotor has a feature that it is difficult to cause precession, and a synergistic effect on the suppression of vibration of the rotor R is expected. Thereby, the problem of the multicopter that the vibration is likely to occur is improved, and the flight disturbance and noise of the multicopter 10 due to the vibration of the rotor R are suppressed.

[Modification of rotor]
4 and 5 are views showing rotors R ₁ and R ₂ which are modifications of the rotor R. FIG.

Rotor _{R 1} in FIG. 4, the motor case 41c of the motor 41 as a driving source, a rotor blade 42b and counterweight 42w are integrated. 4 (a) is a side view of the rotor _{R 1,} FIG. 4 (b) is a plan view showing a cross section taken along A-A position in FIGS. 4 (a).

The motor case 41c of the motor 41 is an outer rotor type motor, by which the blade 42b and the counterweight 42w are integrated, the number of parts and assembling errors of the rotor R ₁ is reduced. This prevents the balance between the blade 42b and the counterweight 42w from being lost due to accumulated errors.

Further, the rotor R ₁ of the present modification, a counterweight 42w by forming thicker than a portion of the thickness of the other portions in the circumferential direction of the motor case 42c. Therefore, a portion of the counterweight 42w, the amount of leakage flux to the outside of the motor case 42c and is suppressed, the output efficiency of the rotor R ₁ is enhanced. In this modification, the blade 42b and the counterweight 42w are integrally formed with the motor case 42c. However, the blade 42b and the counterweight 42w that are separate from the motor case 42c may be coupled to the motor case 42c. Good.

The rotor R ₂ shown in FIG. 5 is an example of a simpler structure of the rotor R. FIG. 5A is a side view of the rotor R ₂ , and FIG. 5B is a plan view of the rotor R ₂ . Rotor R ₂ of this modification is integrated counterweight 42w is the proximal end portion of the blade 42b, during a stationary state of the blade 42b, the center of gravity position are matched in the vertical direction of the blade 42b and the counterweight 42w . Rotor R ₂ is not provided with a spinner, counterweight 42w is exposed to the outside. The disadvantages of the rotor R ₂ when compared with the rotor R are as described above.

[Blade storage method]
FIG. 3 is a diagram illustrating a storage method of the multicopter 10 at the storage location.

As shown in FIG. 3A, in the multicopter 10 of the present embodiment, four arms 11 extend radially from the center of the airframe, and the rotor R is disposed at the tip thereof. In the case of a general rotor having a plurality of blades, the whole blade or a part thereof always protrudes outward from the arm regardless of the angular position of the blade. The protruding blade hinders the transport of the aircraft, and, for example, as shown in FIG. 3 (a), it is necessary to secure a large occupied space D of the aircraft. It causes a decrease.

In the multicopter 10 of this embodiment, since the rotor R is configured by a single blade 42b, the position of the blade 42b of each rotor R is set in the extending direction of the arm 11 on which the rotor R is supported. By locating along the center side of the aircraft, the occupied space D of the multicopter 10 in the storage location can be made compact, and the space efficiency of the storage location can be improved (see FIG. 3B). ). In particular, in the multicopter 10 of this embodiment, since the counterweight 42w is accommodated in the spinner 46, the counterweight 42w does not protrude from the rotor R in the radial direction, and the space saving effect is maximized. Yes.

The embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. For example, in the multicopter 10 of the present embodiment, the rotor R that is the first rotor of the present invention is used for all of the rotors, but even when the rotor R is used only for some of the rotors, there is a limitation. Although it is the purpose, the vibration suppression effect mentioned above and a space saving effect can be acquired. Further, the drive source of the rotor R is not limited to a motor. For example, an engine may be used for a large body.

Claims (7)

An unmanned aerial vehicle that includes a plurality of rotors and controls the attitude and flight movement of the aircraft by adjusting the number of rotations of each of the rotors,
An unmanned aerial vehicle characterized in that at least one of the plurality of rotors is a single rotor having only one blade and a counterweight of the blade. 2. The unmanned aerial vehicle according to claim 1, wherein the position of the center of gravity of the counterweight is higher than the position of the center of gravity of the blade when the first rotor is stationary. The first rotor further has a spinner that covers the base end of the blade;
The unmanned aerial vehicle according to claim 1, wherein the counterweight is accommodated in the spinner. The unmanned aircraft according to claim 4, wherein the counterweight is fixed to an inner peripheral surface of the spinner. 3. The unmanned aerial vehicle according to claim 1 or 2, wherein the counterweight can finely adjust the position of the center of gravity after the first rotor is mounted on the unmanned aircraft. The first rotor has an outer rotor type motor that is a drive source,
The unmanned aircraft according to claim 1 or 2, wherein the blade and the counterweight are integrated with a motor case of the outer rotor type motor. A method for storing an unmanned aerial vehicle having a plurality of rotors,
Each of the rotors is a single rotor having a single blade and a counterweight of the blade;
Each of the rotors is supported by a plurality of arms extending radially from the center of the unmanned aircraft body,
A method of storing an unmanned aerial vehicle including a step of arranging a position of the blade of each rotor toward a center side of the airframe along an extending direction of the arm on which the rotor is supported.

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