JP2016049900A - Flight device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flight device capable of stably passing through even a narrow space by deforming a frame.SOLUTION: A frame 1 includes M links 11 in which M≥2 is set, and a movable joint part 12 for interconnecting these links. A lift generation part 2 includes N rotors 21 in which N≥2 is set. At least one rotor 21 is fitted to the M links 11. The lift generation part 2 generates a lift for raising the frame 1 at least in a vertical direction by the rotor 21. During the flying of the frame 1, a connection angle between the links 11 can be changed via the joint part 12.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a flying device using a plurality of rotors.

  In the following, [n] on the right shoulder indicates a reference number at the end of the specification.

In recent years, research on aircraft using a multi-rotor (hereinafter sometimes simply referred to as “multi-rotor”) has been actively conducted ^[1] . However, since most of them have an invariable body structure, it is difficult to pass through a gap smaller than its own size.

  As an application of multi-rotor, automatic search at disaster sites can be mentioned. At disaster sites, narrow flight paths are expected due to half-open doors and inclined walls. Passing through a gap smaller than the shape of the multi-rotor itself is considered to be very difficult for an aircraft with a rigid structure.

In the past, there was a research ^{[2] in} which the aircraft itself was tilted vertically to pass through the gap at high speed. However, for a multi-rotor in which the rotation axes of a plurality of rotors are parallel, tilting in the vertical direction is a very unstable state, and stable flight is considered difficult.

  Accordingly, the present inventors have focused on the action of passing through the gap like a snake and considered a method of passing through the vertically long gap while keeping the aircraft in a horizontal state. As a result, we have found that this problem can be solved by a multi-rotor with a multi-node link structure that can be deformed on a horizontal plane. In particular, the present inventors have worked on a multi-node link structure and flight control of a quadrotor having four propellers.

  Conventionally, many studies have been made on a robot having a multi-node link structure that moves on the ground and in water, but no attempt has been made in the air. The inventors of the present invention have studied a configuration method of a multi-rotor capable of connecting a link having a built-in propeller in the center with a servo motor having a uniform rotation axis direction and deforming on a two-dimensional plane. In particular, this research aimed to realize a quad-rotor with three joints composed of four propellers.

By the way, research on a multi-rotor whose body structure is unchanged has existed for some time. Among them, Oung et al. ^[3] have been researching the ability of a single propeller module to unite on the ground in any number and to fly in a stereo position while keeping any shape in the air. In this research, the attitude control theory to keep the level under any two-dimensional shape is described, but it does not mention the influence that the deformation in the air gives to the flight control.

The present inventors also obtained the knowledge that flight control of an airframe accompanied by aerial deformation can be realized based on the quadrature attitude and position control theory ^[4], which is the airframe structure unchanged.

  The present invention has been made based on the above findings. An object of the present invention is to provide a flying device that can pass stably even in a narrow space by deforming a frame (structure).

  Means for solving the above-described problems can be described as follows.

(Item 1)
A flying device including a frame and a lift generation unit;
The frame includes M links where M ≧ 2, and a movable joint portion that connects these links.
The lift generation unit includes N rotors where N ≧ 2,
At least one rotor is attached to each of the M links,
The lift generation unit is configured to generate lift that raises at least the frame in the vertical direction by a rotor,
The M links are configured such that a connection angle between the links can be changed via the joint portion while the frame is flying.

(Item 2)
The rotor includes a propeller and a rotating shaft,
The rotating shaft is attached to the link;
The flying device according to claim 1, wherein the propeller is configured to generate lift with respect to the link by rotating about the rotation axis.

(Item 3)
M and N are integers of 4 or more,
The joint portion includes a joint driving portion that changes a connection angle between the links in the joint portion,
The rotation axis of the rotor is arranged along the vertical direction,
And the said rotating shafts are made parallel,
The flying device according to item 2, wherein the link is rotatable via the joint portion in a horizontal plane.

(Item 4)
The flying device according to item 2, wherein the lift generation unit includes a tilt mechanism for changing an angle of a rotation axis of the rotor.

(Item 5)
The flying device according to item 2 or 4, wherein the lift generation unit includes a variable pitch mechanism that changes a pitch of the propeller.

(Item 6)
The flying device according to any one of items 1 to 5, wherein the N rotors are configured to be capable of attitude angle control with at least three degrees of freedom as a whole.

(Item 7)
A method for controlling a flying device according to any one of items 1 to 6,
A control method comprising a step of controlling a connection angle between the links so as to avoid such a state when detecting a state in which the rotation axes of the rotor are aligned or close to each other.

  According to the flying device of the present invention, it is possible to stably pass even in a narrow space by deforming the frame which is a main structure.

1 is a plan view of a flying device according to a first embodiment of the present invention. It is a perspective view in the state where only one link which constitutes the flying device of Drawing 1 was taken out. FIG. 3 is an operation explanatory diagram corresponding to FIG. 2. FIG. 2 is an explanatory diagram showing a state in which the posture is changed in the flying device of FIG. 1. It is a top view of the flying device concerning a 2nd embodiment of the present invention. FIG. 6 is an explanatory diagram showing a state in which the posture is changed in the flying device of FIG. 5. In the flying device which concerns on 3rd Embodiment of this invention, it is a perspective view of the location equivalent to FIG. It is explanatory drawing of the physical model in normal mode for demonstrating the specific Example of a flight apparatus.

(First embodiment)
Hereinafter, a flight device according to an embodiment of the present invention will be described with reference to the accompanying drawings.

  The flying device of the present invention includes a frame 1 and a lift generation unit (rotor) 2 and is configured to perform overall control by a controller 3 (see FIG. 1).

  The frame 1 includes M links 11 in which M ≧ 2, and a movable joint portion 12 that connects these links 11 to each other. Here, in the present embodiment, the number of links 11 is four. In the following description, reference numeral 11 is used when referring to the entire link, and individual links are identified by adding subscripts such as 111 to 11M.

  In the present embodiment, the link 11 has a long shape extending in one direction. Further, a rigid material is used for the link 11 of the present embodiment. However, since the shape and material of the link are mainly determined by the ease of flight control, there are no particular restrictions as long as flight is possible.

  The link 11 of the present embodiment is rotatable via a joint portion 12 in a horizontal plane. That is, the rotation axis of the link 11 in the present embodiment extends in the vertical direction.

  The joint part 12 is an element that connects the links in a relatively rotatable state. Thereby, the M links 11 are configured such that the connection angle between the links can be changed via the joint portion 12 while the frame 1 is flying. In the description of the present embodiment, reference numeral 12 is used as a whole for a plurality of joint portions.

  More specifically, the joint portion 12 of this embodiment includes a joint drive portion 121 that changes the connection angle between the links 11 in the joint portion 12 (see FIG. 2). As the joint drive part 121, the servomotor which can control a rotation angle with the controller 3 can be used, for example.

  In FIG. 2, a servo motor as the joint drive unit 121 is illustrated on one end side (left end side in FIG. 2) of the link 11. This joint drive part 121 is connected to the joint part 12 formed at the end of another adjacent link 11. At the right end of the link 11 in FIG. 2, the joint portion 12 connected to the joint drive portion 121 in another link 11 is described.

  The lift generating unit 2 of the present embodiment includes N rotors 21 where N ≧ 4. More specifically, the lift generating unit 2 of the present embodiment includes four rotors 21. In the description of the present embodiment, the whole of the plurality of rotors is referred to as the rotor 21, and suffixes are used as indicated by reference numerals 211 to 21N when referring to the individual rotors.

  Each rotor 21 in the present embodiment includes a propeller 22 and a rotating shaft 23 (see FIG. 2).

  Each rotating shaft 23 is attached to each link 11. The rotation axis of each rotor 21 in the present embodiment is disposed along the vertical direction, and the rotation axes are parallel to each other. Therefore, the rotation surface of the propeller 22 in the present embodiment is substantially along the horizontal plane.

  More specifically, a rotary motor 231 for rotating the rotary shaft 23 is attached to each rotary shaft 23 in the present embodiment. In this embodiment, the bottom surface of the rotary motor 231 is fixed to the top surface of the link 11, and the rotary shaft 23 is attached to the link 11 via the rotary motor 231. Of course, there are no particular restrictions on the mounting form of the rotary motor 231.

  Each rotation shaft 23 in the present embodiment is set so that the rotation direction is different between the adjacent rotation shafts 23. Since this point is the same as the conventional flight control in the so-called multi-rotor, detailed description thereof is omitted.

  The propeller 22 is configured to generate lift with respect to the link 11 by rotating around the rotation shaft 23.

  In the present embodiment, one rotor 21 is attached to each of the four links 11 (see FIG. 1).

  The lift generation unit 2 of the present embodiment is configured to generate a lift that raises the frame 1 at least in the vertical direction by the rotor 21. Here, the four rotors in the present embodiment are configured to be capable of attitude angle control with at least three degrees of freedom as a whole rotor.

The controller 3 is configured to be able to perform rotation control between the joint drive unit 121 in the joint unit 12 and the rotary motor 231 in the rotary shaft 23. The controller 3 can be configured by a combination of a PC and an appropriate program, for example. Here, the flying device of the present embodiment further includes a sensor (not shown) that measures the position / attitude of the frame 1, and the controller 3 generates a control command based on the output of the sensor. It has become. As the position / posture sensor, for example,
・ Inertia measurement device using three-axis gyro sensor and three-axis acceleration sensor;
A so-called motion capture device that can identify the position and orientation of the flying device from the outside;
Any one or combination of cameras mounted on the frame itself and capable of estimating its own position can be used. It is also possible to use other sensors (for example, a geomagnetic sensor attached to the frame).

  The connection between the controller 3 and each control object or sensor may be wired or wireless.

  Specific examples of the control in the controller 3 will be described in the embodiments described later.

(Operation of the first embodiment)
Next, the operation of the flying device according to the first embodiment will be described with further reference to FIGS.

  First, the initial posture is not particularly limited, but consider a state as shown in FIG. In this state, each rotor 21 is rotated by a command from the controller 3 (see FIG. 3). Thereby, in this embodiment, the upward lift (upward with respect to the paper surface in FIG. 1) can be generated, and the whole including the frame 1 and the lift generator 2 can be raised.

  In the flying device of the present embodiment, the joint drive unit 121 of the joint unit 12 can be driven by a control command from the controller 3. Thereby, for example, a link arrangement as shown in FIG. 4 can be taken.

  In the present embodiment, when the width that the flying device should pass through is narrow, the width of the flying device itself can be reduced by appropriately changing the link arrangement. For this reason, in this embodiment, there exists an advantage that the flight in a narrow place like a disaster site becomes easy, maintaining a stable flight. Therefore, according to this flying device, for example, it is possible to collect information from the air at a disaster site where the flight space is narrow.

  Here, in the flying device of the present embodiment, the four rotors 21 are provided to provide three degrees of freedom, and the joint portion 12 enables the link 11 (that is, the rotor 21) to rotate in a horizontal plane, thereby allowing one degree of freedom to fly. Control (ie, thrust vector control) is possible. For this reason, according to this apparatus, there exists an advantage that a flight is attained, maintaining substantially the same attitude | position (horizontal attitude | position).

  Moreover, according to the flying device of this embodiment, it becomes possible to pinch an object between links by changing the position of the link 11. Therefore, the apparatus of this embodiment can also be used for the purpose of carrying things.

  In the first embodiment, when the rotation shafts 23 of the rotor 21 are arranged in a straight line, the degree of freedom of control is reduced by one and there is a possibility that the control becomes impossible. Such a posture is called a unique posture. Therefore, when the controller 3 according to this embodiment detects a state where the rotation shafts 23 of the rotor 21 are aligned or close to each other, the controller 3 drives the joint drive unit 121 to avoid such a state. Thus, it is preferable to control the connection angle between the links. This can be realized by appropriate means such as detecting the rotation angle between the links. Thereby, it is possible to prevent the flying device from taking a peculiar posture and to improve the safety of the flight.

  In the above-described embodiment, the number of links is four. However, assuming that at least one rotor is attached to one link, the minimum number of links is two. For example, it is possible to arrange two or three rotors on the first link and two or one rotor on the second link.

(Second Embodiment)
Next, a flight device according to a second embodiment of the present invention will be described with reference to FIGS. In the description of the second embodiment, elements that are basically the same as those in the first embodiment described above are denoted by the same reference numerals, thereby avoiding redundant description.

  In the first embodiment described above, a frame is configured using four links 11 (links 111 to 114). On the other hand, in the second embodiment, a frame is configured using six links 11 (links 111 to 116). In this embodiment, the number of rotors 21 is also six, and the number of links and the number of rotors are the same.

  Also in the flight device of the second embodiment, as shown in FIG. 6, there is an advantage that the flight posture can be changed and it is easy to pass through a narrow place.

  Other configurations and advantages of the second embodiment are the same as those of the first embodiment described above, and thus detailed description thereof is omitted.

(Third embodiment)
Next, a flying device according to a third embodiment of the invention will be described with reference to FIG. In the description of the third embodiment, elements that are basically the same as those in the first embodiment described above are denoted by the same reference numerals, thereby avoiding redundant description.

  In the first embodiment described above, the direction of the rotating shaft 23 of the propeller 22 is constant. On the other hand, in the third embodiment, the direction of the rotation shaft 23 can be changed by the tilt mechanism 24. Specifically, the tilt mechanism 24 of the present embodiment is along a rotation axis 241 along a first axis (an axis in a direction in which the joint portions 12 at both ends of the link are connected) and an axis intersecting (orthogonal) with this. It is a gimbal mechanism (see FIG. 7) that includes a rotating shaft 242. In the present embodiment, the controller 3 can control the rotation to a desired angle around these axes 241 and 242.

  In the third embodiment, a variable pitch mechanism 25 that changes the pitch angle (tilt angle) of the propeller 22 is attached. In the present embodiment, the pitch angle of the propeller 22 can be controlled by the variable pitch mechanism 25 based on a control command from the controller 3. Since the variable pitch mechanism 25 can change the direction of exhaust by the propeller 22, it can control to change the direction of propulsive force obtained by the propeller 22.

  According to the third embodiment, since the degree of freedom that can be controlled by one rotor 21 itself is 3, there is an advantage that the minimum number of rotors necessary for flight can be reduced. Assuming that there is one rotor per link, the minimum number of rotors is 2 in this embodiment.

  Moreover, in 3rd Embodiment, since there are many degrees of freedom which can be controlled with one rotor, the joint drive part 121 like 1st Embodiment is omissible. However, even in this case, it is preferable that the joint portion 12 can be freely rotated.

  Furthermore, since the tilt mechanism 24 is provided in the third embodiment, there is an advantage that the specific posture described in the first embodiment is not provided.

  Moreover, if comprised like 3rd Embodiment, it will also become possible to deform | transform the link 11 in three dimensions.

  In the example of FIG. 7, the direction of the rotation axis in the joint portion 12 is different between one end and the other end of the link.

  Other configurations and advantages of the third embodiment are the same as those of the first embodiment described above, and thus detailed description thereof is omitted.

(Example)
Hereinafter, specific examples based on the configuration of the first embodiment will be described.

  The movable range of the joint drive unit (servo motor) 121 in the embodiment is −90 ° to + 90 °. Since all servomotors have the same rotational axis direction, the multi-node link 11 is deformed in a two-dimensional plane. Each link had a length of 480 [mm] and a weight of 380 [g].

  As for the attitude of the aircraft, an IMU board (inertial measurement device) is installed near the center of the frame, and the attitude (roll, pitch, yaw) at that point is estimated. Since the multi-node link in this example can be deformed only on a two-dimensional plane, the roll and pitch values estimated by the IMU board are considered to be those of the entire frame 1.

In the present embodiment, flight control with airborne deformation is realized based on the flight control theory ^[4] of the quad rotor, which is invariant to the airframe structure.

(Attitude control)
The form of the flying device (hereinafter referred to as “quad rotor”) shown in FIG. 8 is referred to as a normal mode, and the joint angles at this time are all 90 °. In the present embodiment, the influence of changing the joint angle within the range of −45 ° ≦ θ ₁ ≦ 90 ° and −45 ≦ θ ₃ ≦ 90 ° on the posture control in the air will be discussed. Based on the control theory described in [4], the rotational motion model of the quad rotor in the normal mode can be described by Equation 1.

及び
I_xy = I_xz = I_yz = 0 が成立する。 In normal mode,

as well as
I _xy = I _xz = I _yz = 0 holds.

であるため、

と近似する。よって、空中変形時の姿勢は式2のようなPID制御器を用いて制
御することができる。 In the case of deformation under the conditions of −45 ° ≦ θ ₁ ≦ 90 ° and −45 ≦ θ ₃ ≦ 90 °, I _xy may not be 0, but I _xx and I _yy are dominant. , I _xy ≈0. Also,

Because

And approximate. Therefore, the attitude during aerial deformation can be controlled using a PID controller such as Equation 2.

(Position control)
The translational motion model of the quadrotor is given by Equation 3.

という前提条件の元でゆっくりと変形していくため、変形時も、多節リンク全体を一つの剛体とみなせる。よって、定位制御に関しては、式4のようなPID制御器を用いることができる。 In this example, the multi-node link is

Therefore, the entire multi-joint link can be regarded as a single rigid body. Therefore, for localization control, a PID controller as shown in Equation 4 can be used.

  The contents of the present invention are not limited to the above embodiments. In the present invention, various modifications can be made to the specific configuration within the scope of the claims.

  For example, as the joint portion, various members can be used as long as the positional relationship between the link members can be changed and the mechanism or material can be controlled.

(List of references cited in this specification)
[1] Vijay Kumar and Nathan Michael. Opportunities and challenges with autonomous micro aerial vehicles.
Vol. 31, pp. 1279 {1291, 2012.
[2] D. Mellinger and V. Kumar. Minimum snap trajectory generation and control for quadrotors. In Robotics and Automation (ICRA), 2011 IEEE International Conference on, pp. 2520 {2525, May 2011.
[3] R. Oung, F. Bourgault, M. Donovan, and R. D'Andrea. The distributed flight array. In Robotics and Automation (ICRA), 2010 IEEE International Conference on, pp. 601 {607, May 2010.
[4] S. Bouabdallah and R. Siegwart. Full control of a quadrotor. In Intelligent Robots and Systems, 2007. IROS 2007. IEEE / RSJ International Conference on, pp. 153 {158, Oct 2007.

DESCRIPTION OF SYMBOLS 1 Frame 11 Link 12 Joint part 121 Joint drive part 2 Lift generating part 21 Rotor 22 Propeller 23 Rotating shaft 231 Rotating motor 24 Tilt mechanism 241, 242 Rotating shaft of tilt mechanism 25 Variable pitch mechanism 3 Controller

Claims (7)

A flying device including a frame and a lift generation unit;
The frame includes M links where M ≧ 2, and a movable joint portion that connects these links.
The lift generation unit includes N rotors where N ≧ 2,
At least one rotor is attached to each of the M links,
The lift generation unit is configured to generate lift that raises at least the frame in the vertical direction by a rotor,
The M links are configured such that a connection angle between the links can be changed via the joint portion while the frame is flying. The rotor includes a propeller and a rotating shaft,
The rotating shaft is attached to the link;
The flying device according to claim 1, wherein the propeller is configured to generate lift with respect to the link by rotating about the rotation shaft. M and N are integers of 4 or more,
The joint portion includes a joint driving portion that changes a connection angle between the links in the joint portion,
The rotation axis of the rotor is arranged along the vertical direction,
And the said rotating shafts are made parallel,
The flying device according to claim 2, wherein the link is rotatable through the joint portion in a horizontal plane. The flying device according to claim 2, wherein the lift generation unit includes a tilt mechanism for changing an angle of a rotation axis of the rotor. The flying device according to claim 2, wherein the lift generation unit includes a variable pitch mechanism that changes a pitch of the propeller. The flying device according to any one of claims 1 to 5, wherein the N rotors are configured to be capable of attitude angle control with at least three degrees of freedom as a whole. A method for controlling a flying device according to any one of claims 1-6,
A control method comprising a step of controlling a connection angle between the links so as to avoid such a state when detecting a state in which the rotation axes of the rotor are aligned or close to each other.

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