JP7196668B2 - flying object - Google Patents

Description

The present disclosure relates to air vehicles.

Rotorcraft, such as helicopters, may land on landing surfaces other than horizontal, such as, for example, inclined surfaces. As a technology for landing a rotorcraft on such a landing surface, the technology described in Patent Document 1 or Patent Document 2 can be considered. US Pat. No. 5,400,000 discloses a vertical landing gear with multiple landing mechanisms extending below the fuselage. When these landing mechanisms receive an impact from the landing surface during landing, they elastically deform in the vertical direction, and this elastic deformation absorbs the impact. US Pat. No. 5,300,002 discloses an aircraft with multiple landing supports that support the fuselage during landing. These landing supports vary in length according to the terrain characteristics of the rough terrain, thereby orienting the aircraft to a substantially horizontal attitude when landing on rough terrain.

JP 2007-245925 A Japanese Patent Publication No. 2015-530318

In order to stabilize the landing of the rotorcraft (flying body) on the landing surface as described above, it is conceivable to land the flying body in a state in which the attitude of the flying body is inclined along the landing surface. However, if the attitude of the flying object is tilted from the horizontal attitude, the horizontal component of the lift force acts on the flying object, which may cause the flying object to move in an unintended direction during landing. Furthermore, the horizontal component of this lift produces a reaction force acting on the aircraft from the landing surface when the aircraft collides with the landing surface. This reaction force may cause rollover of the flying object. Therefore, there is room for improvement in the landing stability of the flying object on the landing surface as described above.

This disclosure describes an air vehicle that can stably land on a landing surface.

The flying object of the present disclosure is a flying object that flies in the air and lands on a landing surface at a landing point, and includes a main body, a thrust force for adjusting the position of the main body, and the attitude of the main body. A thrust generating section that generates a thrust for adjustment, a landing leg that is provided on the main body and supports the main body when it lands on the landing surface, and first information that acquires main body attitude information indicating the current attitude of the main body. an acquisition unit, a second information acquisition unit that acquires landing point information indicating the state of the landing surface, a target attitude of the main body for landing on the landing surface based on the main body attitude information and the landing point information, and a control device for controlling the thrust generating section so that the attitude of is the target attitude.

In this flying object, the position and attitude of the main body in the air are adjusted by adjusting the thrust generated by the thrust generating section. This thrust force generator generates not only a thrust force for adjusting the position of the main body, but also a thrust force for adjusting the posture of the main body. Therefore, by adjusting these thrusts, the position and attitude of the main body can be adjusted independently. Thereby, the posture of the main body can be adjusted while maintaining the position of the main body, and conversely, the position of the main body can be adjusted while maintaining the posture of the main body. As a result, even if the posture of the main body is adjusted (for example, tilted from a horizontal posture) so that the target posture according to the landing surface is achieved during landing, the position of the main body may change unintentionally. situation can be contained. That is, according to the configuration described above, the flying object can be stably landed on the landing surface.

In some aspects, the landing leg includes a ground contact portion that touches the landing surface during landing, and the control device calculates the target attitude of the main body such that a virtual plane defined by the ground contact portion is along the landing surface. good too. In this case, the relative inclination angle between the imaginary plane that defines the grounding portion of the landing leg and the landing surface can be reduced, so that the flying object can be landed on the landing surface more stably.

In some aspects, the control device performs a landing operation that controls the thrust generator to approach the landing point and an attitude control operation that controls the thrust generator so that the attitude of the main body becomes the target attitude, The attitude control operation consists of the first operation of acquiring the main body attitude information and the landing point information, and the second operation of controlling the thrust generating unit so that the main body attitude becomes the target attitude using the main body attitude information and the landing point information. and an operation, wherein the controller may repeatedly perform the first operation and the second operation while performing the landing operation. For example, if the landing site is on board a ship, it is assumed that the condition of the landing surface will change over time. According to the above-described operation, while approaching the landing point by the landing operation, it is possible to adjust the relationship between the state of the landing surface that changes with time and the attitude of the main body in real time by the attitude control operation. As a result, the posture of the main body can be made to follow the state of the landing surface. In other words, even if the state of the landing surface fluctuates over time, the flying object can be stably landed on the landing surface.

In some aspects, the main body may further include a detection unit that detects landing point information, and the second information acquisition unit may acquire the landing point information from the detection unit. In this case, the detection unit can indirectly detect the landing point information of the landing surface based on the current attitude of the main body, for example, by calculating the relative inclination angle of the landing surface with respect to the attitude of the main body. By providing the aircraft with a detection unit that detects landing point information in this way, it is possible to obtain landing point information for any landing surface, not limited to a specific landing surface for which landing point information has been detected in advance. As a result, the flying object can be stably landed on any landing surface, thereby enhancing convenience.

In some aspects, the second information acquisition unit may acquire the landing point information from an external detector provided on the landing surface and detecting the landing point information. In this case, more accurate landing point information can be obtained than when the landing point information is detected indirectly. By adjusting the attitude of the main body based on more accurate landing point information, the flying object can be landed on the landing surface more stably.

In some aspects, the thrust generator includes six rotors arranged around a vertical line passing through the body, and the controller can independently control the rotation speed of each of the six rotors, The six rotors each have a rotation axis inclined at an acute angle with respect to the vertical line, and the rotation surfaces of the six rotors may not be arranged on the same plane. In this case, the six rotors are controlled by the controller to rotate at arbitrary speeds. The axes of rotation of these rotors are inclined at acute angles to the vertical, and the planes of rotation of the rotors are not arranged in the same plane. Therefore, each rotor can generate not only thrust for adjusting the position of the main body, but also thrust for adjusting the attitude of the main body. Therefore, according to the configuration described above, the thrust generating section of the flying object described above can be suitably realized.

In some aspects, the thrust generator includes a plurality of rotors, and the rotation axes of the plurality of rotors, the first axis, the second axis, and the third axis, are arranged at fixed positions with respect to the body. , a plurality of rotors having a rotation center disposed on a first axis and having opposite pitches, a first pair of rotors each having a surface of rotation perpendicular to the first axis, and a rotation center on a second axis. are arranged and have opposite pitches, each having a surface of rotation perpendicular to the second axis; and a third pair of rotors each having a surface of rotation perpendicular to the axis, wherein the controller controls the rotational speeds of the first pair of rotors, the second pair of rotors, and the third pair of rotors independently. The first, second and third axes may be non-coplanar and non-parallel to each other. In this case, the rotors are arranged radially on three non-coplanar rotation axes. By arranging each rotation axis at the above-described position, each rotor can generate not only a thrust for adjusting the position of the main body, but also a thrust for adjusting the posture of the main body. Therefore, according to the configuration described above, the thrust generating section of the flying object described above can be suitably realized.

According to some aspects of the present disclosure, an air vehicle capable of stable landing on a landing surface is provided.

FIG. 1 is a perspective view showing a schematic configuration of an aircraft according to one embodiment. FIG. 2 is a block diagram showing the electrical configuration of the aircraft. FIG. 3 is a block diagram showing the configuration of the control device shown in FIG. 2. As shown in FIG. FIG. 4 is a flow chart showing a landing control method for an aircraft. FIGS. 5(a) and 5(b) are schematic diagrams for explaining a landing control method for an aircraft. 6(a) and 6(b) are schematic diagrams for explaining a landing control method for an aircraft. FIG. 7 is a schematic diagram showing an aircraft according to a first modified example. FIG. 8 is a perspective view showing a schematic configuration of an aircraft according to a second modification. FIG. 9 is a perspective view showing a schematic configuration of an aircraft according to a third modification. FIG. 10 is a perspective view showing a schematic configuration of an aircraft according to a fourth modification. FIGS. 11(a) and 11(b) are schematic diagrams for explaining problems of the flying object according to the comparative example.

BEST MODE FOR CARRYING OUT THE INVENTION 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 overlapping descriptions are omitted as appropriate. In the following description, a case where the flying object according to the present invention is an unmanned aerial vehicle (hereinafter referred to as UAV (Unmanned Aerial Vehicle)) will be described. In the following description, XYZ orthogonal coordinates (three-dimensional coordinates) are defined with the Z axis as the vertical axis and the XY plane as the horizontal plane. The vertical direction along the vertical axis may be called the Z direction, the first horizontal direction may be called the X direction, and the second horizontal direction perpendicular to the first horizontal direction may be called the Y direction. Also, the “position” of a certain configuration means the coordinate position of the configuration with reference to three-dimensional coordinates. The “attitude” of a certain configuration means the inclination of the configuration with respect to each axis of the three-dimensional coordinates.

FIG. 1 is a perspective view showing a schematic configuration of an aircraft 1 according to this embodiment. The aircraft 1 is, for example, a multirotor aircraft (rotary wing aircraft). The flying object 1 flies in the air and lands on a landing surface LP (see, for example, FIG. 5(a)) at a landing point. In this embodiment, a case where the landing surface LP is an inclined surface is illustrated. However, the landing surface LP is not limited to an inclined surface, and may be a horizontal surface or a surface with large undulations. Further, in this embodiment, it is assumed that the landing surface LP is on a transport device (moving object) such as a ship, and the position and inclination of the landing surface LP are to change with time.

As shown in FIG. 1, an aircraft 1 includes a main body 2, a frame 3 attached to the main body 2, a thrust generator 5 for generating thrust to be applied to the main body 2, and landing legs 15 for supporting the main body 2 during landing. and The main body 2 accommodates, for example, control equipment for the aircraft 1 and the like. The main body 2 has, for example, a rectangular parallelepiped shape extending in the XY directions, and is arranged in the center of the aircraft 1 . Further, in this embodiment, the body 2 is provided with a cavity, and this cavity forms an opening 2a on each of the four side surfaces of the body 2 . The four side surfaces are two side surfaces facing each other in the X direction and two side surfaces facing each other in the Y direction among the surfaces of the rectangular parallelepiped of the main body 2 .

The frame 3 is a rod-shaped member extending outward from the main body 2 , that is, in a direction away from the main body 2 . Each rotor 11 of the thrust generator 5 is arranged on each frame 3 . Each frame 3 is attached to the main body 2 so as to radially extend from the main body 2 . In the example shown in FIG. 1, six frames 3 are attached to the main body 2, but the number of frames 3 can be changed as appropriate. Further, the frame 3 may be configured integrally with the main body 2 by using members common to the main body 2 .

The thrust generator 5 has a plurality of rotors 10 provided on the main body 2 and a plurality of rotors 11 provided on the plurality of frames 3 respectively. Each rotor 10 is arranged, for example, in four openings 2a formed in the body 2, respectively. Each rotor 10 is attached to, for example, the rotating shaft of a motor 34 (see FIG. 2) provided in the hollow portion of the main body 2 and is rotated by the rotational drive of the motor 34 . The rotation axis of each rotor 10 extends along the horizontal X direction or Y direction. Specifically, the rotation axes of the pair of rotors 10 facing each other in the X direction are both along the X direction, and the rotation axes of the pair of rotors 10 facing each other in the Y direction are both along the Y direction. .

By rotating each rotor 10 having a rotation axis along the horizontal direction in this manner, each rotor 10 generates thrust in the horizontal direction. Note that the rotation axis of the rotor 10 may extend along a direction inclined from the X direction or the Y direction toward the Z direction. Even in such a case, thrust in the horizontal direction can be obtained from the X-direction component or the Y-direction component of the thrust generated by the rotor 10 . Further, in the example shown in FIG. 1, the rotor 10 has two blades, but it is not limited to this. The rotor 10 may have, for example, three or more blades.

The plurality of rotors 11 are attached to the tip portions of the plurality of frames 3 , respectively, and arranged around a vertical line N passing through the main body 2 . In the example shown in FIG. 1, six rotors 11 are arranged around a vertical line N at equal intervals, and the aircraft 1 is a hexacopter-type aircraft 1 . The rotation centers 11a of the six rotors 11 are positioned, for example, on the same plane, and are arranged on the vertices (that is, corner positions) of a regular hexagon when viewed from the Z direction.

The six rotors 11 do not necessarily have to be arranged on the vertices of a regular hexagon, and may be arranged on the vertexes of a hexagon having a pair of sides facing each other longer than the other sides. Also, the six rotors 11 may not necessarily be arranged on the same plane, and may be arranged at positions shifted from each other in the Z direction. If the six rotors 11 are arranged symmetrically with respect to a predetermined horizontal line, the control system of the aircraft 1 can be simplified, and the design and implementation of the aircraft 1 can be facilitated.

The rotor 11 is attached to, for example, the rotating shaft of a motor 34 (see FIG. 2) provided at the tip of the frame 3 and is rotated by the rotational drive of the motor 34 . The rotation axis of each rotor 11 is along the Z direction, for example. When each rotor 11 having a rotation axis along the Z direction is rotated in this manner, each rotor 11 generates thrust (lift) in the Z direction. Note that the rotation axis of the rotor 11 may be along a direction inclined from the Z direction toward the XY plane. Further, although the rotor 11 has three blades in the example shown in FIG. 1, the number of blades is not limited to this. The rotor 11 may have, for example, two or more blades. Further, although the example shown in FIG. 1 shows the aircraft 1 having six rotors 11, the number of rotors 11 may be less than six or more than six.

Thus, the thrust generating section 5 has not only the rotor 11 that generates thrust in the vertical direction, but also the rotor 10 that generates thrust in the horizontal direction. Therefore, the horizontal direction component of the thrust of each rotor 11 generated when the posture of the main body 2 is tilted can be canceled by the horizontal direction component of the thrust of each rotor 10 . Thereby, only the posture of the main body 2 can be adjusted while the horizontal position of the main body 2 is maintained. Conversely, the horizontal position of the main body 2 can be adjusted while maintaining the posture of the main body 2 . Therefore, by having the rotor 10 in the thrust generating section 5, not only can the translational motion be independently adjusted with respect to each of the X-, Y-, and Z-axes, but also the rotational motion can be independently adjusted with respect to each axis. That is, translational motion and rotational motion can be independently controlled with respect to each axis, and the aircraft 1 can fly with six degrees of freedom.

The landing leg 15 is attached to the lower surface of the main body 2 (that is, the surface on the landing surface LP side in the Z direction). The landing legs 15 include a pair of skids 16 that are provided substantially symmetrically with respect to the center of the main body 2 in the X direction and extend in the Y direction, and a plurality of connection members 17 that connect each skid 16 and the main body 2 in the Z direction. and includes The skid 16 is a rod-shaped member extending in the Y direction, and the connection member 17 is a rod-shaped member extending in the Z direction. The skid 16 includes a ground contact portion 16a that contacts the landing surface LP during landing.

The grounding portion 16a of each skid 16 defines one virtual plane VP (see, for example, FIG. 5(a)). The virtual plane VP is, for example, a plane that includes all of the grounding portions 16a of the pair of skids 16. As shown in FIG. The virtual plane VP is along the orientation of the main body 2, for example. The virtual plane VP follows the horizontal plane, for example, when the posture of the main body 2 is horizontal along the horizontal plane, and when the posture of the main body 2 is tilted from the horizontal posture, the virtual plane VP is tilted from the horizontal plane in accordance with the tilt. . Note that the configuration of the landing leg 15 is not limited to the example shown in FIG. The landing leg 15 may have any configuration as long as it can support the main body 2 on the landing surface LP during landing. Also, the virtual plane VP may be inclined from the horizontal plane when the posture of the main body 2 is horizontal.

FIG. 2 is a block diagram showing the electrical configuration of the aircraft 1. As shown in FIG. In FIG. 2, a solid line indicates a power supply system, and a broken line indicates a communication system (control system). As shown in FIG. 2, the main body 2 includes a control device 20 that controls each part of the aircraft 1, a battery 23 that is a power source for driving each part of the aircraft 1, and a power supply that supplies power to each part of the aircraft 1. and a substrate 24 . The main body 2 also includes a first information acquisition unit 25 for detecting its current position and attitude, a detection unit 30 for detecting the position and inclination of the landing surface LP at the landing point, and a plurality of motors 34 for driving each. and a motor amplifier 33 of .

The first information acquisition unit 25 includes, for example, a gyro sensor 26, a GPS (Global Positioning System) sensor 27, an air pressure sensor 28, and an acceleration sensor 29. The gyro sensor 26 detects the angular acceleration of the flying object 1, and the acceleration sensor 29 detects the acceleration of the flying object 1 in the Z direction and the acceleration in the XY directions. The gyro sensor 26 and the acceleration sensor 29 may be integrated with their respective functions. Also, the first information acquisition unit 25 may include a sensor (for example, a force sensor or a pressure sensor) that directly detects an external force applied to the flying object 1 .

The first information acquisition unit 25 acquires sensor data output from these sensors at a predetermined cycle, and uses, for example, an appropriate estimation algorithm based on the sensor data to obtain the current position and orientation of the main body 2. is estimated. In this manner, the first information acquisition unit 25 detects the main body posture information D1 and outputs the main body posture information D1 to the control device 20 each time it acquires sensor data.

The “position” of the main body 2 may be, for example, the center position of the main body 2 or the center of gravity of the main body 2 . Alternatively, the “position” of the main body 2 may be a position other than the central position and the center of gravity of the main body 2 . Further, the main body orientation information D1 may be information that directly indicates the current position and orientation of the main body 2 or information that indirectly indicates the current position and orientation of the main body 2 . Even if the main body attitude information D1 is information indicating the current position and attitude of another part of the aircraft 1, the current position and attitude of the main body 2 can be derived from the positional relationship between that part and the main body 2. Therefore, the main body orientation information D1 may be information indicating the current position and orientation of a portion other than the main body 2 (for example, the frame 3 or the like).

The detector 30 includes, for example, a distance sensor 31 that measures the distance to the landing surface LP. The distance sensor 31 measures the distance to the landing surface LP by, for example, emitting light (or radio waves) toward the landing surface LP and detecting light (or radio waves) reflected from the landing surface LP. The distance sensor 31 outputs measurement results at a predetermined cycle (real time).

The detection unit 30 receives measurement results from the distance sensor 31 . Every time the distance sensor 31 outputs a measurement result, the detection unit 30 detects the relative position between the position of the main body 2 and the position of the landing surface LP, and the position of the main body 2 and the landing surface LP based on the measurement result. Calculate the relative tilt angle to the tilt. Then, the detection unit 30 calculates landing point information D2 indicating the position and inclination of the landing surface LP based on the calculated relative position and relative inclination angle and the current position and attitude of the main body 2 . That is, the landing point information D2, which is information indicating the state of the landing surface LP, may include the position and inclination angle of the landing surface LP. The detection unit 30 outputs the calculated landing point information D2 to the second information acquisition unit 32 .

The second information acquisition section 32 acquires the landing point information D2 from the detection section 30 and outputs the acquired landing point information D2 to the control device 20 . The output period of the second information acquisition section 32 is synchronized with the output period of the first information acquisition section 25, for example. Note that the detection unit 30 may be provided outside the aircraft 1 . In this case, the second information acquisition section 32 only needs to have a function of receiving the landing point information D2 from the external detection section 30 .

The landing point information D2 may be information directly indicating the position and inclination of the landing surface LP, or may be information indirectly indicating the position and inclination of the landing surface LP. For example, even if the landing point information D2 is information indicating the position and inclination of a portion other than the landing surface LP, if the position and inclination of the landing surface LP can be derived from that information, the landing point information D2 can be Information indicating a position and an inclination may be used.

The control device 20 is, for example, a computer configured by hardware such as a CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory), and software such as programs stored in the ROM. be. The control device 20 rotates each motor 34 via each motor amplifier 33 based on the main body posture information D1 output from the first information acquisition unit 25 and the landing point information D2 output from the detection unit 30. to control the rotation of each rotor 10 and 11 .

FIG. 3 is a block diagram showing the configuration of the control device 20. As shown in FIG. As shown in FIG. 3, the controller 20 controls, for example, a calculator 21 that calculates a target position and a target attitude of the main body 2 for landing on the landing surface LP, and the rotational speeds of the rotors 10 and 11. A rotor control unit 22 is included. The body posture information D1 output from the first information acquisition unit 25 and the landing point information D2 output from the second information acquisition unit 32 are periodically input to the calculation unit 21 . The calculator 21 calculates the target position and target attitude of the main body 2 based on the input main body attitude information D1 and landing point information D2.

The "target position and target attitude" are the target position and attitude of the main body 2 for landing the aircraft 1 on the landing surface LP during or before landing. The "target position" may be, for example, the sky above the position of the landing surface LP. Specifically, the "target position" may be a position that is a predetermined distance in the Z direction (that is, offset) from the position of the landing surface LP. However, the "target position" is not limited to a position at a predetermined distance in the Z direction from the position of the landing surface LP, and may be a position further shifted in the horizontal direction from the position at a predetermined distance. Also, the "target position" may be, for example, the position of the landing surface LP.

The "target attitude" may be, for example, an attitude along the landing surface LP. Specifically, the "target attitude" may be the attitude of the main body 2 when the virtual plane VP defined by the ground contact portion 16a of the landing leg 15 is along the landing plane LP. The fact that the virtual plane VP is along the landing surface LP means that the flying object 1 is in a posture capable of stably landing on the landing surface LP. Specifically, the virtual plane VP along the landing surface LP means that the virtual plane VP and the landing surface LP are parallel to each other, and that the virtual plane VP is slightly inclined with respect to the landing surface LP. include.

The calculator 21 calculates the target position and the target attitude each time the main body attitude information D1 and the landing point information D2 are input. Therefore, when the new main body attitude information D1 and the landing point information D2 are input, the calculation section 21 outputs information D3 indicating a new target position and new target attitude calculated based on them to the rotor control section 22, Repeat this. "New target position and target attitude" means the target position and target attitude calculated based on the latest body attitude information D1 and landing point information D2 input in real time. The "new target position" may be, for example, a position lower than the previously calculated target position. That is, the "new target position" may be a position shifted toward the landing surface LP in the Z direction from the previously calculated target position. The "new target attitude" may be the attitude of the main body 2 according to the current inclination of the landing surface LP. That is, the "new target attitude" may be the attitude of the main body 2 when the virtual plane VP is along the current inclination of the landing surface LP.

When the information D3 indicating the target position and target attitude is input, the rotor control unit 22 calculates the target thrust and target torque for realizing the target position and target attitude, and generates the calculated target thrust and target torque. The rotation speeds of the rotors 10 and 11 are calculated so as to cause the rotation to occur. That is, the rotor control unit 22 calculates the rotational speeds of the rotors 10 and 11 so that the position and orientation of the main body 2 are at the target position and orientation. The rotor control unit 22 outputs information D4 indicating this rotational speed to each motor amplifier 33 (see FIG. 2).

Since the information D3 indicating the target position and the target attitude is periodically input to the rotor control unit 22 from the calculation unit 21, the rotor control unit 22 updates the information D4 indicating the rotation speed each time this information is input. Output to each motor amplifier 33 . Therefore, when the information D3 indicating the new target position and target attitude is input from the calculation unit 21, the rotor control unit 22 outputs the information D4 indicating the new rotation speed to each motor amplifier 33 based on the information D3. , repeat this. Each motor amplifier 33 receives information D4 indicating the rotation speed and supplies current to each motor 34, and each motor 34 rotates each rotor 10, 11 at the rotation speed and rotation direction according to the information D4.

To summarize the above operation, when the main body attitude information D1 and the landing point information D2 are input to the control device 20, the target position and target attitude are calculated by the calculation unit 21, and the position and the target attitude of the main body 2 are calculated by the rotor control unit 22. The rotational speeds of the rotors 10 and 11 are controlled so that the postures are at the target positions and postures. After that, when new main body attitude information D1 and landing point information D2 are input to the control device 20, the calculation unit 21 calculates a new target position and new target attitude, and the rotor control unit 22 controls the position and attitude of the main body 2. The rotational speeds of the rotors 10 and 11 are controlled again so that the new target positions and orientations are obtained. While repeating these operations, the aircraft 1 lands on the landing surface LP. A method of determining whether or not the position and attitude of the main body 2 are at the target position and attitude will be described in the following description of the landing control method.

A landing control method for the aircraft 1 having the above configuration will be described. FIG. 4 is a flow chart showing an example of a landing control method for the aircraft 1. As shown in FIG. 5(a), 5(b), 6(a), and 6(b) are schematic diagrams for explaining the landing control method of the aircraft 1. FIG.

First, when the main body attitude information D1 and the landing point information D2 are input, the control device 20 controls the rotation of the rotors 10 and 11 so that the current position of the main body 2 becomes the target position (Fig. 5 ( a) see). The target position may be, for example, above the landing surface LP. After that, as shown in FIG. 4, the control device 20 determines whether or not the current position matches the target position (step S1). Specifically, the control device 20 determines whether the difference between the current position and the target position is within the allowable range.

When control device 20 determines that the difference between the current position and the target position is within the allowable range (Yes in step S1), it determines that the current position matches the target position. On the other hand, when control device 20 determines that the difference between the current position and the target position is not within the allowable range (No in step S1), it determines that the current position does not match the target position. In this case, the controller 20 performs feedback control based on the difference between the current position and the target position, and again controls the rotation of the rotors 10 and 11 so that the current position of the main body 2 matches the target position. Then, step S1 is executed again.

When the controller 20 determines that the current position matches the target position (Yes in step S1), the controller 20 starts descending toward the landing surface LP (step S2: landing operation). This landing operation continues until the landing is confirmed in the landing determination in step S6, which will be described later. After starting the landing operation (step S2), the body attitude information D1 and the landing point information D2 are obtained (step S3). Using this information, the rotation of each rotor 10, 11 is controlled so that the current attitude becomes the target attitude (see FIG. 5(b)). First, the control device 20 determines whether or not the current attitude matches the target attitude (step S4). Specifically, the control device 20 determines whether the difference between the current attitude and the target attitude is within the allowable range. That is, the control device 20 determines whether or not the maximum relative inclination angle of the virtual plane VP with respect to the landing surface LP is within the allowable range.

When the control device 20 determines that the difference between the current attitude and the target attitude is within the allowable range (Yes in step S4), the control device 20 determines that the current attitude matches the target attitude. On the other hand, when the control device 20 determines that the difference between the current attitude and the target attitude is not within the allowable range (No in step S4), it determines that the attitude of the main body 2 does not match the target attitude. In this case, the control device 20 executes feedback control based on the difference between the current attitude and the target attitude, and again controls the rotation of the rotors 10 and 11 so that the current attitude matches the target attitude (step S5). Then, step S3 is executed again.

When the control device 20 determines that the current attitude matches the target attitude (Yes in step S4), it determines whether or not the vehicle has landed on the landing surface LP (step S6). If the landing is confirmed (Yes in step S6), the series of control ends. If the landing is not confirmed (No in step S6), the process returns to step S3.

When the position and orientation of the main body 2 are adjusted to the target position and orientation, the orientation may be adjusted after the position is adjusted as shown in FIG. The position may be adjusted after the Alternatively, the position and orientation may be adjusted simultaneously. Further, when the result of step S4 is No, the operation of detecting landing may be performed as in step S6 before and after the operation of changing the attitude (step S5).

Actions and effects obtained by the flying object 1 according to the present embodiment described above will be described together with problems of the comparative example. FIG. 11 is a schematic diagram for explaining problems of the flying object 100 according to the comparative example. Unlike the flying object 1 according to the present embodiment, the flying object 100 according to the comparative example does not have the rotor 10 and the detecting unit 30 of the thrust generating unit 5 . Therefore, the aircraft 100 does not have the rotor 10 that generates thrust in the horizontal direction, but only the rotor 11 that generates thrust in the vertical direction. Therefore, the flying object 100 has only four degrees of freedom of motion (that is, acceleration in the vertical direction and angular acceleration in the roll, pitch, and yaw directions), which makes it difficult to control the position and attitude independently. be.

Therefore, in the flying object 100, the attitude tends to fluctuate when the position is adjusted, and conversely, the position fluctuates when the attitude is adjusted. Therefore, as shown in FIG. 11A, when the flying object 100 lands on a landing surface LP such as an inclined surface, if the attitude of the flying object 100 is tilted along the landing surface LP, the attitude changes. There is a possibility that unintended horizontal movement may occur along with this. Furthermore, when the flying object 100 collides with the landing surface LP due to such unintended movement, as shown in FIG. There is a risk that it will occur. Therefore, there is room for improvement in the landing stability of the aircraft 100 on the landing surface LP such as an inclined surface.

In order to stabilize landing on such a landing surface LP, it is conceivable to deform the landing leg that touches the landing surface LP (for example, Patent Document 1 or Patent Document 2). However, the landing gear must be strong enough to support the weight of the main body of the aircraft. may increase to some extent. As a result, the weight of the aircraft increases, and various problems such as the decrease in the weight of articles that can be loaded by the aircraft and the decrease in the flight time of the aircraft can occur.

In addition, when the landing gear is elastically deformed as in Patent Document 1, the magnitude of the impact that the aircraft receives from the landing surface depends on the descent speed of the aircraft during landing, the hardness of the landing surface, and the like. Therefore, it is assumed that the landing gear cannot sufficiently absorb the reaction force received from the landing surface. Therefore, if the landing leg cannot sufficiently absorb the reaction force from the landing surface, problems such as the rollover described above may occur, and the landing of the aircraft may become unstable.

On the other hand, in the aircraft 1 according to this embodiment, the position and attitude of the main body 2 in the air are adjusted by adjusting the thrust generated by the thrust generating section 5 . The thrust generator 5 has not only a rotor 11 that generates thrust in the XY directions, but also a rotor 10 that generates thrust in the Z direction. Therefore, by adjusting these thrusts, the position and posture of the main body 2 can be adjusted independently. Thereby, the posture of the main body 2 can be adjusted while the position of the main body 2 is maintained, and conversely, the position of the main body 2 can be adjusted while the posture of the main body 2 is maintained. Therefore, when landing on the landing surface LP of the landing point, the position and attitude of the main body 2 can be maintained at the target position and target attitude, respectively. As a result, even if the attitude of the main body 2 is adjusted (for example, tilted from the horizontal attitude) so as to achieve a desired attitude according to the landing surface LP during landing, the position of the main body 2 unintentionally fluctuates. It is possible to prevent such situations. That is, according to the configuration described above, the flying object 1 can be stably landed on the landing surface LP. Furthermore, since it is not necessary to deform the landing leg 15 in order to stably land the flying object 1 on the landing surface LP, an increase in the weight of the flying object 1 can be suppressed.

In the aircraft 1 according to the present embodiment, the landing leg 15 includes the ground contact portion 16a that touches the landing surface LP during landing, and the calculator 21 calculates that the virtual plane VP defined by the ground contact portion 16a extends along the landing surface LP. Thus, the target posture is calculated. According to this configuration, since the relative inclination angle between the virtual plane VP and the landing surface LP can be reduced, the aircraft 1 can be landed on the landing surface LP more stably.

In the aircraft 1 according to this embodiment, the control device 20 controls the landing operation to control the thrust generator 5 so as to approach the landing point, and controls the thrust generator 5 so that the attitude of the main body 2 becomes the target attitude. Attitude control operation includes a first operation of acquiring body attitude information D1 and landing point information D2, and using body attitude information D1 and landing point information D2 to determine the target attitude of the body 2. and a second operation of controlling the thrust generating unit 5 to take the attitude, and the control device 20 repeatedly executes the first operation and the second operation during the landing operation. As in this embodiment, when the landing point is on board, it is assumed that the position and inclination of the landing surface LP change over time. According to the above-described operation, while approaching the landing point by the landing operation, it is possible to adjust the relationship between the position and inclination of the landing surface LP that fluctuates with time and the position and attitude of the main body 2 in real time by the attitude control operation. becomes. As a result, the position and attitude of the main body 2 can follow the position and inclination of the landing surface LP. In other words, even if the state of the landing surface LP fluctuates over time, the flying object 1 can stably land on the landing surface LP.

The aircraft 1 according to the present embodiment is provided in the main body 2 and includes a detection unit 30 that detects landing point information D2. ing. As described above, the detection unit 30 calculates the relative position of the landing surface LP with respect to the current position of the main body 2 and the relative inclination angle of the landing surface LP with respect to the current attitude of the main body 2, thereby obtaining the main body 2 Landing point information D2 can be indirectly detected based on the current position and attitude of . By providing the aircraft 1 with the detection unit 30 for detecting the landing point information D2 in this way, the landing point information D2 of any landing surface LP is not limited to the specific landing surface for which the landing point information D2 has been detected in advance. is obtained. As a result, it is possible to stably land the flying object 1 on any landing surface LP, thereby enhancing convenience.

The present disclosure is not limited to the embodiments described above. For example, various modifications shown in FIGS. 7, 8, 9, and 10 may be adopted.

FIG. 7 is a schematic diagram showing an aircraft 1A according to the first modified example. In this modification, the main body 2 does not have the detection section 30, and an external detection section 30A is provided on the landing surface LP. The external detection unit 30A detects landing point information D2 indicating the position and inclination of the landing surface LP, and provides the detected landing point information D2 to the second information acquisition unit 32 of the main body 2. The second information acquisition unit 32 is configured to be able to communicate wirelessly with the external detection unit 30A, for example, and receives (acquires) the landing point information D2 from the external detection unit 30A. The second information acquisition section 32 outputs the received landing point information D2 to the control device 20 . According to this modified example, more accurate landing point information D2 can be obtained than in the case where the landing point information D2 is indirectly detected as in the above embodiment. By adjusting the position and attitude based on the more accurate landing point information D2, the flying object 1A can be more stably landed on the landing surface LP.

FIG. 8 is a perspective view showing a schematic configuration of an aircraft 1B according to a second modification. The difference between this modified example and the above embodiment is the configuration of the rotor of the thrust generating section. That is, the thrust generating section 5A according to this modified example has one rotor 13 instead of the plurality of rotors 10 . Further, the main body 2A according to this modified example does not have the opening 2a of the above-described embodiment. The rotor 13 is provided on the upper surface of the main body 2A (that is, the surface opposite to the landing surface LP in the Z direction). The rotation axis of the rotor 13 is along the X direction, which is the horizontal direction. By rotating the rotor 13 having the rotation axis along the X direction in this way, the rotor 13 generates thrust in the X direction.

Here, in this modified example, unlike the above-described embodiment, the thrust generating section 5A has a rotor 13 that generates a thrust in only one horizontal direction. Therefore, the rotor control unit 22 cannot simultaneously adjust the attitude of the main body 2A in both the one direction and the horizontal direction orthogonal to the one direction. Therefore, in this modified example, the rotor control unit 22 adjusts the attitude of the main body 2A separately in each direction. For example, with the rotation axis of the rotor 13 along the X direction, the rotor control unit 22 adjusts the posture of the main body 2A in the X direction, and then rotates the main body 2A around the Z axis so that the rotation axis of the rotor 13 is adjusted. along the Y direction, the posture of the main body 2A is adjusted in the Y direction.

Thus, even if the thrust generating section 5A has the rotor 13 that generates thrust in only one horizontal direction, the position and attitude of the main body 2A can be independently adjusted. It has the same effect. Note that the rotation axis of the rotor 13 may extend along a direction inclined from the X direction toward the Z direction. Even in such a case, a thrust force in the X direction can be obtained from the X direction component of the thrust force generated by the rotor 13 . Further, in the example shown in FIG. 8, the rotor 13 is provided on the upper surface of the main body 2A, but it may be provided on another surface of the main body 2A, and may be provided on a portion other than the main body 2A (for example, the frame 3, etc.). may be provided.

FIG. 9 is a perspective view showing a schematic configuration of an aircraft 1C according to a third modified example. The difference between this modification and the above-described embodiment is the configuration of the thrust generating section. In this modified example, the thrust generating section 5B does not have the rotor 10, and has a pair of rotors 11A, a pair of rotors 11B, and a pair of rotors 11C arranged at symmetrical positions with respect to the vertical line N. 11 has been replaced. Moreover, in this modified example, an aircraft 1C includes a main body 2A shown in FIG. In the above embodiment, the rotation axis of the rotor 11 was along the Z direction, but in this modified example, the rotation axes A of the rotors 11A, 11B, and 11C are inclined at an acute angle with respect to the Z direction. The rotation axis A of one rotor 11A (left side in FIG. 9) is inclined by an inclination angle θ to the side opposite to the main body 2A. The rotation axis A of the other rotor 11A (right side in FIG. 9) is inclined toward the main body 2A by an inclination angle θ. The tilt angle θ is, for example, within a range larger than 0° and smaller than 90°. The rotation axes A of the rotors 11A are parallel to each other, and the rotation surfaces of the rotors 11A are arranged on two parallel planes.

The rotation axis A of one rotor 11B is inclined at an inclination angle θ toward the main body 2A, and the rotation axis A of the other rotor 11B is inclined at an inclination angle θ toward the side opposite to the main body 2A. The rotation axes A of the rotors 11B are parallel to each other, and the rotation surfaces of the rotors 11B are arranged on two parallel planes. Similarly, the rotation axis A of one rotor 11C is inclined toward the main body 2A by an inclination angle θ, and the rotation axis A of the other rotor 11C is inclined toward the main body 2A by an inclination angle θ. there is The rotation axes A of the rotors 11C are parallel to each other, and the rotation surfaces of the rotors 11C are arranged on two parallel planes.

In a pair of rotors facing each other with the vertical line N in between, the inclination angles θ are equal, but the directions of inclination with respect to the vertical line N are opposite to each other. Since the pair of rotors tilt in different directions, the surfaces of rotation of the rotors are not arranged on the same plane. In this manner, the axis of rotation of each rotor is tilted at an acute angle with respect to the vertical line, and the plane of rotation of each rotor is not arranged in the same plane. and rotational motion can be independently controlled, and the aircraft 1C can fly with 6 degrees of freedom. Therefore, according to this modification, as in the above-described embodiment, it is possible to suppress unintended changes in the position and attitude of the main body 2A during landing, so that the aircraft 1C can stably land on the landing surface LP. can be made

FIG. 10 is a perspective view showing a schematic configuration of an aircraft 1D according to the fourth modification. The difference between this modification and the above-described embodiment is the configuration of the thrust generating section. In this modification, the thrust generating section 5C does not have the rotors 10, and replaces the rotors 11 with the first pair of rotors 11D, the second pair of rotors 11E, and the third pair of rotors 11F. have. Further, in this modified example, an aircraft 1D includes a main body 2A shown in FIG. Each rotor 11D shares a rotation axis A1 (first axis), and the rotation axis A1 extends along the X direction. The rotation center 11a of each rotor 11D is arranged on the rotation axis A1. The two frames 3A forming the rotation axis A1 are fixed so that their positions are fixed with respect to the main body 2A. The rotation surface of each rotor 11D is orthogonal to the rotation axis A1. Each rotor 11 has a mutually opposite pitch.

The second pair of rotors 11E share a rotation axis A2 (second axis), and the rotation axis A2 extends along the Y direction. The rotation center 11a of each rotor 11E is arranged on the rotation axis A2. The two frames 3A forming the rotation axis A2 are fixed so that their positions are fixed with respect to the main body 2A. The rotation surface of each rotor 11E is orthogonal to the rotation axis A2. Each rotor 11E has a mutually opposite pitch. The third pair of rotors 11F share a rotation axis A3 (third axis), and the rotation axis A3 extends along the Z direction. The rotation center 11a of each rotor 11F is arranged on the rotation axis A3. The two frames 3A forming the rotation axis A3 are fixed so as to be positioned with respect to the main body 2A. The rotation surface of each rotor 11F is perpendicular to the rotation axis A3. Each rotor 11F has a mutually opposite pitch.

Thus, the rotation axes A1, A2, A3 are not in the same plane and are non-parallel to each other. Further, the rotation axes A1, A2 and A3 intersect at the center point of the main body 2A. In this modification, the rotors 11D, 11E, 11F are radially arranged on three rotation axes A1, A2, A3 that do not lie on the same plane. The pair of rotors have pitches opposite to each other, and each rotates about the rotation axis at an arbitrary number of rotations. Therefore, translational motion and rotational motion can be independently controlled with respect to each of the rotation axes A1, A2, and A3, and the aircraft 1D can fly with six degrees of freedom. Therefore, according to this modification, as in the above-described embodiment, it is possible to suppress unintended changes in the position and attitude of the main body 2A during landing. can be made

The present disclosure is capable of other various modifications. For example, the embodiments and modifications described above may be combined with each other according to the desired purpose and effect. Also, the configurations of the main body, the frame, the thrust generating section, and the landing gear can be changed as appropriate. For example, the body may further comprise working equipment such as, for example, a camera or a robotic arm. The equipment mounted on the main body can be appropriately changed according to the work required for the aircraft 1 and the like. Moreover, the number, arrangement, and shape of the rotors of the thrust generating section are not limited to those of the above-described embodiment and modifications. Further, the thrust generating section may have a configuration other than the rotor as long as it can generate thrust for adjusting the position and posture of the main body.

Also, the configuration of the control device may be changed as appropriate. For example, the second information acquisition unit does not have to periodically acquire the landing point information. For example, when the position and inclination of the landing surface do not change with time, such as when the landing surface is the surface of the earth, the second information acquisition unit may acquire the landing point information once. In this case, the calculation section does not need to calculate new target positions and target orientations, and the rotor control section does not need to adjust the position and orientation of the main body so as to achieve the new target positions and orientations. The control system of the aircraft can be simplified.

1, 1A-1D Aircraft 2, 2A Main body 3, 3A Frames 5, 5A-5C Thrust generators 10, 11, 11A-11C, 13 Rotor 11D First pair of rotors 11E Second pair of rotors 11F Third A pair of rotors 11a rotation center 15 landing leg 16a grounding portion 20 control device 21 calculation portion 22 rotor control portion 25 first information acquisition portion 30 detection portion 30A external detection portion 32 second information acquisition portion 33 motor amplifier 34 motor A rotation axis A1 rotation axis (first axis)
A2 rotation axis (second axis)
A3 rotation axis (third axis)
D1 Body attitude information D2 Landing point information N Plumb line LP Landing surface VP Virtual plane

Claims (6)

An aircraft that flies through the air and lands on a landing surface of a landing site,
the main body;
a thrust generating unit provided in the main body and generating a thrust for adjusting the position of the main body and a thrust for adjusting the attitude of the main body;
landing legs provided on the main body for supporting the main body when landing on the landing surface;
a first information acquisition unit that acquires body posture information indicating the current posture of the body;
a second information acquisition unit that acquires landing point information indicating the state of the landing surface;
Control for calculating a target attitude of the main body for landing on the landing surface based on the main body attitude information and the landing point information, and controlling the thrust generating section so that the attitude of the main body becomes the target attitude a device;
with
The control device is
a landing operation that controls the thrust generator to approach the landing point;
an attitude control operation for controlling the thrust generating section so that the attitude of the main body becomes the target attitude;
The attitude control operation includes:
a first operation of acquiring the body attitude information and the landing point information;
a second operation of controlling the thrust generating unit so that the attitude of the main body becomes the target attitude using the main body attitude information and the landing point information;
The flying object , wherein the control device alternately and repeatedly executes the first operation and the second operation two or more times during execution of the landing operation . The landing leg includes a grounding portion that touches the landing surface during landing,
2. The flying object according to claim 1, wherein said control device calculates said target attitude of said main body such that a virtual plane defined by said ground contact portion is along said landing surface. Further comprising a detection unit provided in the main body for detecting the landing point information,
The flying object according to claim 1 or 2 , wherein the second information acquiring section acquires the landing point information from the detecting section. The flying object according to claim 1 or 2 , wherein the second information acquisition section acquires the landing point information from an external detection section that is provided on the landing surface and detects the landing point information. The thrust generating unit includes six rotors arranged around a vertical line passing through the main body,
The control device is capable of independently controlling the rotation speeds of the six rotors,
The six rotors each have a rotation axis inclined at an acute angle with respect to the vertical line,
The aircraft according to any one of claims 1 to 4 , wherein the rotating surfaces of the six rotors are not arranged on the same plane. The thrust generator includes a plurality of rotors,
a first axis, a second axis, and a third axis, which are rotation axes of the plurality of rotors, are arranged at fixed positions with respect to the main body;
The plurality of rotors are
a first pair of rotors having a center of rotation disposed on the first axis and having opposite pitches, each having a surface of rotation orthogonal to the first axis;
a second pair of rotors having a center of rotation disposed on the second axis and having opposite pitches, each having a surface of rotation orthogonal to the second axis;
a third pair of rotors having a center of rotation disposed on the third axis and having opposite pitches, each having a surface of rotation orthogonal to the third axis;
The control device is capable of independently controlling the rotational speeds of the first pair of rotors, the second pair of rotors, and the third pair of rotors,
The aircraft according to any one of claims 1 to 4 , wherein said first axis, said second axis and said third axis are not on the same plane and are non-parallel to each other.

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