JP2016135660A - Aircraft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aircraft capable of realizing a motion that requires high maneuverability including work in a narrow space and contact with an outside.SOLUTION: An aircraft comprises: a first pair of rotors 11 and 12 each having a rotation center disposed on a first axis to be opposite to each other in pitching, and having rotation surfaces orthogonal to the first axis, respectively; a second pair of rotors 13 and 14 each having a rotation center disposed on a second axis to be opposite to each other in pitching, and having rotation surfaces orthogonal to the second axis, respectively; a third pair of rotors 15 and 16 each having a rotation center disposed on a third axis to be opposite to each other in pitching, and having rotation surfaces orthogonal to the third axis, respectively; and a control unit capable of independently controlling rotation speeds of the first paired rotors 11, 12, the second paired rotors 13, 14, and the third paired rotors 15, 16, the first axis, the second axis, and the third axis being not present on the same plane and non-parallel to one another.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an aircraft having a plurality of rotor blades.

  In a conventional rotary wing aircraft (helicopter) equipped with a main rotor and a tail rotor, the control model is complex and difficult to control because multiple control inputs such as the rotational speed and elevation angle of the rotor are coupled to each other. It was. In contrast, the counter rotating rotor mechanism does not require a tail rotor. The counter rotating rotor mechanism can generate a thrust without a reaction force in the yaw direction.

  For example, in the flying robot described in Patent Document 1, the counter torque generated by the two rotary blades is canceled by adopting the counter rotating rotor mechanism. In addition, the flying robot is provided with a tilt adjustment mechanism that tilts the upper part of the airframe with respect to the lower part of the airframe around the X direction and the Y direction so that the center of gravity of the airframe can be moved.

  On the other hand, an aircraft including six rotors has been studied. For example, in the flying object described in Non-Patent Document 1, the rotors are arranged so that the centers of the six rotors are located on the same plane passing through the center of the aircraft. In another form described in Non-Patent Document 1, the rotors are arranged so that the centers of the three rotors are positioned on two parallel planes passing above and below the center of the airframe. In the various flying objects described in Non-Patent Document 1, the rotation surfaces of a pair of rotors (that is, two rotors) are positioned on each of three planes orthogonal to each other.

Japanese Patent No. 5392891

Bill Crowther, Alexander Lanzon, Martin Maya-Gonzalez, and David Langkamp, University of Manchester, KinematicAnalysis and Control Design for a Nonplanar Multirotor Vehicle, Journal of Guidance, Control, and Dynamics, Vol. 34, No. 4, 1157-1171, July -August 2011

  As described above, attempts have been made to simplify the mechanism and improve the controllability of the conventional aircraft. However, in the flying object described in Patent Document 1, it is difficult to control the posture and the movement in the translation direction independently, and the posture must be changed in order to perform the translational movement. Moreover, even if the purpose is to change the posture, if the posture is changed, movement in the translational direction has occurred. For this reason, when the flying object moves in a narrow space, an unintended posture change occurs with the movement, and the flying object may collide with an obstacle. Further, when the robot mounted on the flying object performs an operation involving contact with an external structure or the like, there is a possibility that the flying object cannot maintain a stable flight due to a reaction force received from the structure. In the flying object described in Non-Patent Document 1, the control is complicated.

  An object of this invention is to provide the flying body which can implement | achieve the exercise | movement which requires high maneuverability, such as a narrow work and contact with the external environment, easily.

  A flying object according to an aspect of the present invention is a flying object in which a first axis, a second axis, and a third axis, which are rotation axes of a plurality of rotors, are arranged at fixed positions with respect to a main body. A rotation center is disposed on one axis and has a reverse pitch, a first pair of rotors each having a rotation surface orthogonal to the first axis, and a rotation center is disposed on the second axis and a reverse pitch. And a second pair of rotors each having a rotation surface orthogonal to the second axis, and a rotation surface having a reverse pitch with a rotation center disposed on the third axis and having a rotation pitch orthogonal to the third axis. A first pair of rotors, and a control unit capable of independently controlling the rotation speeds of the first pair of rotors, the second pair of rotors, and the third pair of rotors, respectively, The axis, the second axis, and the third axis do not exist on the same plane and are non-flat. It is.

According to this flying object, three pairs, that is, six rotors are arranged radially on three rotation axes that do not exist on the same plane. The first pair of rotors have opposite pitches, and are controlled by the control unit to rotate around the first axis at an arbitrary rotational speed. When the rotational speed of _one rotor is ω ₁ and the rotational speed of the other rotor is ω ₂ , the thrust F in the first axis direction is proportional to the sum of the squares of the rotational speed (ω ₁ ² + ω ₂ ² ). . The moment M in the rotational direction around the first axis is proportional to (ω ₁ ² −ω ₂ ² ), which is the difference between the squares of the rotational speed. That is, the following formula (1) is established.

  From equation (1), it can be seen that an inverse matrix exists in this matrix T. Therefore, the thrust F and moment M can be controlled independently with respect to the first axis. Similarly, the thrust and moment can be controlled independently with respect to the second axis and the third axis. As described above, the translational and rotational motions can be independently controlled with respect to each of the first axis, the second axis, and the third axis that are not on the same plane and are non-parallel. Therefore, the flying object can fly with six degrees of freedom, and can easily realize a movement requiring high maneuverability such as working in a narrow place or contact with the outside world.

  In some forms, the first axis, the second axis, and the third axis extend in directions perpendicular to each other. In this case, the first axis, the second axis, and the third axis constitute an orthogonal coordinate system. High-speed and high-precision control can be performed around any rotation axis.

  In some embodiments, each of the first axis, the second axis, and the third axis forms an oblique coordinate system. In this case, since all the rotors greatly contribute to the movement around the reference line (in particular, the thrust in the reference line direction), the efficiency with respect to the movement in the reference line direction is increased.

  In some forms, the first axis, the second axis, and the third axis intersect at one point. In this case, it becomes easy to obtain thrust and moment (that is, torque).

  In some forms, the first axis, the second axis, and the third axis pass through the body, the body is located between the first pair of rotors and between the second pair of rotors. And located between the third pair of rotors. In this case, since the center of gravity of the flying object can be positioned at the center of the six rotors, simple control becomes possible. Moreover, efficiency is increased.

  ADVANTAGE OF THE INVENTION According to this invention, the exercise | movement which requires high mobility, such as a narrow work and contact with the external world, is realizable.

1 is a perspective view showing a schematic configuration of a flying object according to a first embodiment of the present invention. (A) is a figure which shows typically arrangement | positioning of the rotor of 1st Embodiment, (b) is a figure which shows a pair of rotor in (a), (c) is typical figure of arrangement | positioning of the rotor of 2nd Embodiment. FIG. It is a block diagram which shows the structure of the payload part which is a main body. It is a figure which shows an example of the control law in a control part. (A)-(c) is a figure which shows an example of the flight state in the narrow part by the conventional flight body. (A) And (b) is a figure which shows an example of the flight state at the time of the contact operation | work by the conventional flying body.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant descriptions are omitted. In the following description, the case where the present invention is applied to an unmanned aerial vehicle (hereinafter referred to as UAV) will be described.

  As shown in FIG. 1, the flying object 1 of the present embodiment includes a payload portion (main body) 2 disposed in the center, six frames 3 that are fixed to the payload portion 2 and extend outward, And six rotors 10 attached to the tip of the frame 3. That is, the flying object 1 is a multi-rotor aircraft (rotary wing aircraft) including six rotors 10. The aircraft 1 which is a UAV can independently generate a motion component with six degrees of freedom that combines the motion in the rotation and translation directions. Therefore, the flying object 1 can fly in a narrow part or fly with a contact operation.

  As shown in FIG. 1 and FIG. 2 (a), the rotor 10 of the flying object 1 includes a first rotor 11, a second rotor 12, a third rotor 13, which are arranged at the center of each surface of the cube. The fourth rotor 14, the fifth rotor 15, and the sixth rotor 16 are included. The payload portion 2 is disposed between the first rotor 11 to the sixth rotor 16. Details of the arrangement of the rotor 10 will be described later.

  As shown in FIG. 3, the payload unit 2 includes a control unit 20 for controlling each unit of the aircraft 1, a battery 21 that is a power source for driving each unit of the aircraft 1, and a power source for each unit. A power supply board 22 for supply is mounted. Motors 31 to 36 for rotating the first rotor 11 to the sixth rotor 16 are attached to the distal end portion of each frame 3. The payload unit 2 is equipped with six motor amplifiers 30 for controlling the rotational speeds of these motors 31 to 36. Each motor amplifier 30 is supplied with power from the battery 21 via the power supply board 22. Each motor amplifier 30 is controlled by the control unit 20 to supply current to the motors 31 to 36 so that the motors 31 to 36 rotate at a predetermined rotation speed and rotation direction.

  The control unit 20 is a computer composed of hardware such as a CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory), and software such as a program stored in the ROM. . The control unit 20 can communicate wirelessly with a transmitter (not shown) operated on the ground, for example. The control unit 20 receives a command from the transmitter, and controls the motor amplifier 30 to cause the flying object 1 to fly at a predetermined (target) position, posture or operation based on the current position and posture of the flying object 1. Each of the motors 31 to 36 is controlled. The controller 20 can independently control the rotation speeds of the first rotor 11, the second rotor 12, the third rotor 13, the fourth rotor 14, the fifth rotor 15, and the sixth rotor 16. In FIG. 3, a solid line indicates a power supply system, and a broken line indicates a communication system (control system).

  Various sensors 23 are mounted on the payload unit 2. These sensors 23 are devices for estimating the position and posture of the flying object 1. In the example shown in FIG. 3, for example, a gyro sensor 24, a GPS (Global Positioning System) 25, and an atmospheric pressure sensor 26 are provided. These sensors 23 output data indicating the measurement result to the control unit 20. Based on the sensor data output from the sensors 23, the control unit 20 estimates the current position and orientation of the flying object 1 using, for example, an appropriate estimation algorithm.

  In addition to the above-described devices, the payload unit 2 can be equipped with additional devices such as a camera and a robot arm. The device mounted on the payload unit 2 can be appropriately changed according to the flight and work required for the flying object 1. Depending on the position and weight of the device mounted on the payload section 2, the weight of the payload section 2 and the position of the center of gravity can change. In the flying object 1, the first rotor 11 to the sixth rotor 16 are rotationally controlled in consideration of the weight of the payload portion 2 and the position of the center of gravity.

Next, an example of a control law in the control unit 20 will be described with reference to FIG. The control unit 20 acquires the target position and / or target posture of the flying object 1. Further, the control unit 20 acquires the current position and posture of the flying object 1 based on sensor data output from the sensors 23 of the payload unit 2. The control unit 20 calculates a target thrust and a target torque for realizing the target position and / or target posture by performing dynamic calculation. In FIG. 4, _{F x} is thrust in the X-axis direction, _{F y} is the Y-axis direction of the thrust, the _{F z} represents the thrust in the Z-axis direction. M _x is the moment about the X axis, _{M y} is moment around the Y axis, the _{M z} represents the moment about the Z axis.

Assuming that the rotation speeds of the first rotor 11 to the sixth rotor 16 are ω ₁ to ω ₆ , the transfer function T is used to determine what thrust and moment are obtained when the rotor is rotated. Is represented by the following formula (2).

In the flying object 1 in which the arrangement of the first rotor 11 to the sixth rotor 16 is uniquely devised, the transfer function T has an inverse matrix. Therefore, the rotational speed of the rotor can be calculated using the following equation (3) according to the target thrust and torque.

  Returning to FIG. 1 and FIG. 2, the arrangement and configuration of the first rotor 11 to the sixth rotor 16 will be described in detail. The aircraft 1 has three rotation axes A1 to A3. In the flying object 1, the three rotation axes A1 to A3 extend in directions perpendicular to each other.

  More specifically, the first rotor 11 and the second rotor 12 (first pair of rotors) are arranged along two surfaces facing the Z-axis direction of the cube. That is, the rotation surfaces of the first rotor 11 and the second rotor 12 are parallel to the two surfaces. The rotation center 11a of the first rotor 11 and the rotation center 12a of the second rotor 12 are disposed on the first axis A1. The first axis A1 is parallel to the Z-axis direction. The two frames 3 and 3 constituting the first axis A1 are fixed so that their positions are determined with respect to the payload portion 2. The rotation surfaces of the first rotor 11 and the second rotor 12 are orthogonal to the first axis A1.

  The third rotor 13 and the fourth rotor 14 (second pair of rotors) are arranged along two surfaces facing the cube in the Y-axis direction. That is, the rotation surfaces of the third rotor 13 and the fourth rotor 14 are parallel to the two surfaces. The rotation center 13a of the third rotor 13 and the rotation center 14a of the fourth rotor 14 are disposed on the second axis A2. The second axis A2 is parallel to the Y axis direction. The two frames 3 and 3 constituting the second axis A2 are fixed so that their positions are determined with respect to the payload portion 2. The rotation surfaces of the third rotor 13 and the fourth rotor 14 are orthogonal to the second axis A2.

  The fifth rotor 15 and the sixth rotor 16 (third pair of rotors) are arranged along two surfaces facing the cube in the X-axis direction. That is, the rotation surfaces of the fifth rotor 15 and the sixth rotor 16 are parallel to the two surfaces. The rotation center 15a of the fifth rotor 15 and the rotation center 16a of the sixth rotor 16 are disposed on the third axis A3. The third axis A3 is parallel to the X axis direction. The two frames 3 and 3 constituting the third axis A3 are fixed so that their positions are determined with respect to the payload portion 2. The rotation surfaces of the fifth rotor 15 and the sixth rotor 16 are orthogonal to the third axis A3.

  Thus, the first axis A1, the second axis A2, and the third axis A3 do not exist on the same plane and are not parallel to each other. Furthermore, the first axis A1, the second axis A2, and the third axis A3 intersect at the center point of the cube. In other words, the distances from the intersections of the first axis A1, the second axis A2, and the third axis A3 to the rotation centers 11a to 16a of the rotors 11 to 16 are equal. The first axis A1, the second axis A2, and the third axis A3 pass through the area of the payload portion 2. The payload portion 2 is located between the first rotor 11 and the second rotor 12, located between the third rotor 13 and the fourth rotor 14, and between the fifth rotor 15 and the sixth rotor 16. Is located.

  The first rotor 11 and the second rotor 12 have opposite pitches. The third rotor 13 and the fourth rotor 14 have opposite pitches. The fifth rotor 15 and the sixth rotor 16 have opposite pitches. These pitches are equal in size. The pitches may be different in size, but the calculation in the control unit 20 is easier when the pitches are equal.

  The first rotor 11 and the second rotor 12 can be rotated in opposite directions with respect to the first axis A <b> 1 when the control unit 20 controls the rotation of the motor 31 and the motor 32. The third rotor 13 and the fourth rotor 14 are rotatable in the opposite direction with respect to the second axis A <b> 2 when the motor 33 and the motor 34 are rotationally controlled by the control unit 20. The fifth rotor 15 and the sixth rotor 16 can be rotated in opposite directions with respect to the third axis A <b> 3 by controlling the rotation of the motor 35 and the motor 36 by the control unit 20. The first rotor 11 and the second rotor 12, the third rotor 13 and the fourth rotor 14, the fifth rotor 15 and the sixth rotor 16 can be rotated in the same direction with respect to the respective axes A1, A2 and A3. ing.

According to the flying object 1 of the present embodiment, the three pairs, that is, the six rotors 11 to 16 are arranged radially on the three rotation axes A1, A2, and A3 that do not exist on the same plane. The first rotor 11 and the second rotor 12 have opposite pitches, and are controlled by the control unit 20 to rotate around the first axis A1 at an arbitrary rotational speed. When the rotational speed of the first rotor 11 is ω ₁ and the rotational speed of the second rotor 12 is ω ₂ , the thrust F in the first axis A1 direction is the sum of the squares of the rotational speed (ω ₁ ² + ω ₂ ² ). Is proportional to The moment M in the rotational direction about the first axis A1 is proportional to (ω ₁ ² −ω ₂ ² ), which is the difference between the squares of the rotational speed. That is, the following formula (1) is established.

  From equation (1), it can be seen that an inverse matrix exists in this matrix T. Therefore, the thrust F and the moment M can be controlled independently with respect to the first axis A1. Similarly, the thrust and moment can be independently controlled with respect to the second axis A2 and the third axis A3. As described above, the translational and rotational motions of the first axis A1, the second axis A2, and the third axis A3 that are not on the same plane and are not parallel can be independently controlled. In the air vehicle 1, since the conventional counter rotating rotor is utilized, easy control is possible. As described above, the flying object 1 can fly with six degrees of freedom, and can easily realize a movement requiring high maneuverability such as a narrow work or contact with the outside world. Moreover, according to the flying object 1, since modeling is easy, construction of a control system is easy and high-speed and highly accurate control is attained.

A specific driving example in the flying object 1 will be described. First, to perform simple hovering, only F _z is a thrust in the Z-axis direction, it may be generated to overcome the force of gravity. Therefore, by rotating the first rotor 11 and the second rotor 12 in the opposite directions at the same rotational speed, hovering becomes possible.

For example, when moving in the Y-axis direction, if the third rotor 13 and the fourth rotor 14 are further rotated in the opposite directions at the same rotational speed from the above-described hovering state, the thrust F _{y in the} Y-axis direction is generated. Translational movement becomes possible.

  For example, when rotating around the X axis, if the third rotor 13 and the fourth rotor 14 are rotated in the same direction at the same rotation speed in the above-described hovering state, the reaction force torque of the rotor causes the rotation around the X axis. It becomes possible to perform rotation. At the same time, as the rotor pair of the fifth rotor 15 and the sixth rotor 16 faces the vertical direction (Z-axis direction), the rotational speeds of the first rotor 11 and the second rotor 12 are reduced, and the fifth rotor 15 and the sixth rotor are reduced. Increase the number of revolutions of 16. By such control, it is possible to change the body posture while maintaining the hovering state.

  In the conventional flying object, the motion of 4 degrees of freedom (that is, the acceleration in the vertical direction and the angular acceleration in the roll, pitch, and yaw directions) is operated to realize the state of 6 degrees of freedom. It was difficult to achieve a desired position and posture. For example, when flying in a narrow state in a horizontal state, if the flying object is likely to be swept away by a gust of wind, it is necessary to change the posture in order to maintain the posture. As a result of the attitude change, the flying object may collide with the structure. In addition, when performing contact work by flying the flying object, if the flying object is brought close to the object in order to bring the tool into contact with the object, the attitude movement of the flying object may be restrained by the reaction force generated by the contact. It was. As a result, the control of the flying object may be difficult.

  In this regard, in the flying object 1 of the present embodiment, when flying in a horizontal state in a narrow part (see FIG. 6A), even when the flying object 1 is likely to be washed away by a gust of wind (see FIG. 6 ( b)), it is not necessary to change the posture in order to maintain the posture. Since the attitude can be maintained, the flying object 1 is prevented from colliding with the structure (see FIG. 6C). Further, when the flying object 1 is made to fly and contact work is performed, even when the flying object 1 is brought close to the object in order to bring the tool 40 into contact with the object (see FIG. 7A), the reaction caused by the contact is caused. It can be adjusted according to the force so that the attitude of the flying object 1 is maintained (see FIG. 7B).

  According to the flying object 1 of the present embodiment, since the motion of 6 degrees of freedom can be independently controlled by inputting 6 degrees of freedom, it is easy to realize the state of 6 degrees of freedom.

  Further, since the first axis A1, the second axis A2, and the third axis A3 form an orthogonal coordinate system, high-speed and high-precision control is possible around any rotation axis.

  Since the first axis A1, the second axis A2, and the third axis A3 intersect at one point, it is easy to obtain a thrust and a moment (that is, torque).

  According to the configuration in which the payload portion 2 is disposed between the six rotors 10, the center of gravity of the flying object 1 can be positioned at the center of the rotor 10, and thus simple control is possible. Moreover, efficiency is increased.

  In the present invention, the three axes are not necessarily orthogonal to each other as in the above-described aircraft 1. Depending on the direction of thrust required and / or the direction of rotation, three axes may be installed on the oblique coordinate system. In the aircraft 1A shown in FIG. 2C, each of the first axis A1, the second axis A2, and the third axis A3 is cos θ = 1 with respect to the Z-axis direction line (reference line) passing through the payload portion 2. It extends at an angle (θ≈54.7) that becomes / √3. In this case, the first axis A1, the second axis A2, and the third axis A3 constitute an oblique coordinate system. The distances from the intersections of the first axis A1, the second axis A2, and the third axis A3 to the rotation centers of the rotors 11 to 16 are, for example, equal. In addition, the inclination angles of the first axis A1, the second axis A2, and the third axis A3 with respect to the Z-axis direction line are, for example, equal.

  In the air vehicle 1A having such a configuration, as in the air vehicle 1, the translation and the non-parallel first axis A1, the second axis A2, and the third axis A3 do not exist on the same plane. The rotational movement can be controlled independently. Therefore, the flying object 1 can fly with six degrees of freedom, and can realize a movement requiring high maneuverability such as working in a narrow space or contact with the outside world. In particular, since all the rotors 11 to 16 greatly contribute to the movement around the Z-axis direction line (particularly, the thrust in the vertical direction), the efficiency with respect to the vertical movement is increased. A space for the payload portion 2 is easily secured.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment. In the flying object 1, the case where the distance from the intersection of the three axes to the rotation center of each rotor is the same has been described, but the position of the rotor (or propeller) can be freely arranged on each axis.

  The main body is not limited to the case where the payload portion 2 as the main body is disposed between the six rotors 11 to 16, and the main body may be disposed outside the six rotors. The main body may be disposed only between the rotors.

  The three rotation axes need not intersect at one point. Only two rotation axes may intersect or all three rotation axes may be in a twisted relationship.

  In addition to the six rotors, one or more auxiliary or spare rotors may be further provided. The present invention is not limited to being applied to UAV, and may be applied to manned aircraft.

1 Aircraft 2 Payload (Main body)
DESCRIPTION OF SYMBOLS 10 Rotor 11 1st rotor 11a Rotation center 12 2nd rotor 12a Rotation center 13 3rd rotor 13a Rotation center 14 4th rotor 14a Rotation center 15 5th rotor 15a Rotation center 16 6th rotor 16a Rotation center 20 Control part A1 1st Axis A2 Second Axis A3 Third Axis

Claims (5)

A flying body in which a first axis, a second axis, and a third axis, which are rotation axes of a plurality of rotors, are arranged at fixed positions with respect to the main body
A first pair of rotors having a rotation center disposed on the first axis and having a reverse pitch and each having a rotation plane orthogonal to the first axis;
A second pair of rotors having a rotation center disposed on the second axis and having a reverse pitch, each having a rotation surface perpendicular to the second axis;
A third pair of rotors having a rotation center disposed on the third axis and having a reverse pitch, each having a rotation plane perpendicular to the third axis;
A control unit capable of independently controlling the rotation speeds of the first pair of rotors, the second pair of rotors, and the third pair of rotors,
The aircraft, wherein the first axis, the second axis, and the third axis do not exist on the same plane and are not parallel to each other.   The aircraft according to claim 1, wherein the first axis, the second axis, and the third axis extend in directions perpendicular to each other.   The flying object according to claim 1, wherein each of the first axis, the second axis, and the third axis forms an oblique coordinate system.   The flying object according to any one of claims 1 to 3, wherein the first axis, the second axis, and the third axis intersect at one point.   The first axis, the second axis, and the third axis pass through the main body, the main body is positioned between the first pair of rotors, and between the second pair of rotors. The flying object according to any one of claims 1 to 4, wherein the flying object is located and located between the third pair of rotors.

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