Robot

Abstract

To provide a robot capable of executing an appropriate posture control.SOLUTION: A robot 10 includes a first portion 11 and a second portion 13 coupled to each other. The second portion 13 includes a moving member to be moved to vary at least one of buoyancy and the center of gravity as a whole robot 10 and a drive unit for moving the moving member by two-dimentional parallel movement. The drive unit outputs power source for moving the moving member as well as includes a power source fixed to the first portion 11.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a robot. [Background technology]

[0002] BACKGROUND ART Underwater robots are known that control their posture, such as pitch angle and roll angle, by being provided with floats driven by link mechanisms or the like (see, for example, Non-Patent Document 1). [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Norimitsu Sakagami, Mizuho Shibata, Tomohiro Ueda, Kensei Ishizu, Kenshiro Yokoi, and Sadao Kawamura, “Numerical and Experimental Analysis of Portable Underwater Robots with a Movable Float Device”, Journal of Robotics and Mechatronics Vol.33 No.6,2021 Summary of the Invention [Problem to be solved by the invention]

[0004] In underwater robots equipped with floats for attitude control, as in the above-mentioned conventional technology, it is desirable to achieve proper attitude control regardless of the working environment. However, in adverse environments, such as those with strong tidal currents or many obstacles, it may be difficult to drive the float against the external force of the tidal current, or the float may come into contact with an obstacle, making it difficult to perform proper attitude control. Furthermore, a power transmission mechanism equipped with two independent power sources has been known as a mechanism for moving a moving member, such as a float, through two-dimensional translational motion. In an underwater robot equipped with such a power transmission mechanism, if the power sources move together with the moving member, the center of buoyancy and center of gravity tend to fluctuate, which may make it difficult to perform proper attitude control. For example, when a power source, which is a heavy object, moves while moving a float due to attitude control, a large buoyancy is required, which may cause the center of gravity to easily fluctuate along with the center of buoyancy.Furthermore, when a power source, which is a float, moves while moving a weight such as a counterweight due to attitude control, a large weight is required, which may cause the center of buoyancy to easily fluctuate along with the center of gravity.

[0005] An object of the present invention is to provide a robot that can perform appropriate posture control. [Means for solving the problem]

[0006] In order to solve the above problems and achieve the above object, the present invention employs the following aspects. (1): A robot according to one aspect of the present invention (e.g., robot 10 in the embodiments) comprises a first part (e.g., first part 11 in the embodiments) and a second part (e.g., second part 13 in the embodiments) that are connected to each other, and the second part comprises a moving member (e.g., moving member M in the embodiments) that can be moved to change at least one of the center of buoyancy and the center of gravity of the entire first part and the second part, and a drive unit (e.g., drive unit 40 in the embodiments) that moves the moving member by two-dimensional translational motion, and the drive unit comprises a power source (e.g., power source 41 in the embodiments) that outputs power to move the moving member and is fixed to the first part.

[0007] (2) In the robot described in (1) above, the moving member may include a buoyant member that generates buoyancy (for example, the buoyant member Ma in the embodiment).

[0008] (3) In the robot described in (2) above, the second part may include a cover member (for example, the cover member 30 in the embodiment) that covers the entire moving member and the driving unit.

[0009] (4): In the robot described in any one of (1) to (3) above, the drive unit includes a transmission mechanism (for example, the transmission mechanism 43 in the embodiment) that transmits the power output from the power source to the moving member, and the transmission mechanism includes a ring-shaped member (for example, the ring-shaped member 45 in the embodiment) that is arranged to form an H-shaped circular path having a first path portion (for example, the first path portion 43a in the embodiment) and a second path portion (for example, the second path portion 43b in the embodiment) that are arranged parallel to each other, and a third path portion (for example, the third path portion 43c in the embodiment) that is connected perpendicularly to each of the first path portion and the second path portion, and The annular member may be attached to two sets of drive pulleys (e.g., drive pulley 47a in the embodiment) and driven pulleys (e.g., driven pulley 47b in the embodiment) fixed to the ends thereof, four bend pulleys (e.g., bend pulley 47c in the embodiment) to which the annular member is attached between each of the first path section, the second path section and the third path section, and which move along each of the first path section and the second path section, and a support member (e.g., support member 49 in the embodiment) fixed to a single portion of the annular member in the third path section, which supports the moving member, and which moves along each of the first path section, the second path section, or the third path section. [Effects of the Invention]

[0010] According to the above (1), since the power source is fixed, there is no need to secure space required for moving, for example, signal lines and power lines connected to the power source, and the moving member can be made larger to facilitate control of the center of buoyancy and center of gravity. Furthermore, since the power source does not move with the moving member, fluctuations in the center of buoyancy and center of gravity can be suppressed, improving the ease of control of the center of buoyancy and center of gravity.

[0011] In the case of (2) above, since the power source does not move together with the buoyant member, fluctuations in the center of buoyancy and center of gravity can be suppressed, and the ease of control of the center of buoyancy and center of gravity can be improved.

[0012] In the case of (3) above, even in adverse environments, such as when the relative flow of water becomes high speed due to water currents such as ocean currents and tides or the robot's motion state, or when there are many obstacles, the torque capacity of the drive unit can be reduced by the cover member, preventing difficulty in performing attitude control. Furthermore, an increase in fluid resistance of the moving members and drive unit can be suppressed, which can suppress an increase in the power required to drive the moving members and drive unit, and can also suppress an increase in the size of the power source and power source.

[0013] In the case of (4) above, in a transmission mechanism using a so-called H-BOT or H-type gantry robot, the annular members are arranged in a serpentine circular path on the same plane, so that the increase in space required for arranging the transmission mechanism can be suppressed compared to when the annular members are arranged stacked in two layers, for example. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a perspective view showing a configuration of a robot according to an embodiment of the present invention. [Figure 2] FIG. 3 is an exploded perspective view showing the configuration of a second portion of the robot according to the embodiment of the present invention. [Figure 3] FIG. 2 is a plan view showing the configuration of a driving unit of the robot according to the embodiment of the present invention. [Figure 4] 5A to 5C are schematic diagrams illustrating an example of the operation of a transmission mechanism of a robot according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, a robot according to an embodiment of the present invention will be described with reference to the accompanying drawings. The robot 10 of the embodiment is, for example, an unmanned mobile object on water or underwater, such as an unmanned undersea vehicle (UUV) or an unmanned surface vehicle (USV). For example, an unmanned underwater vehicle, such as a UUV, includes a remotely operated ROV (remotely operated vehicle) and an autonomous underwater vehicle (AUV). For example, a remotely operated ROV includes a so-called underwater drone.

[0016] FIG. 1 is a perspective view showing the configuration of a robot 10 according to an embodiment. In the following description, the X-axis, Y-axis, and Z-axis directions, which are orthogonal to one another in three-dimensional space, are parallel to each other. For example, as shown in Fig. 1, the X-axis direction is parallel to the front-to-rear direction of the robot 10, the Y-axis direction is parallel to the left-to-right direction of the robot 10, and the Z-axis direction is parallel to the up-to-down direction of the robot 10. For example, the positive direction of the X-axis is the forward direction of the robot 10, the positive direction of the Y-axis is the leftward direction of the robot 10, and the positive direction of the Z-axis is the upward direction of the robot 10.

[0017] As shown in FIG. 1, the robot 10 comprises a lower first section 11 and an upper second section 13 that are connected to each other. The first section 11 includes, for example, a plurality of connecting members 21a and frame members 21b that form a first skeleton F1. The outer shape of each of the plurality of connecting members 21a is, for example, a columnar shape extending in the vertical direction. The plurality of connecting members 21a are fixed to, for example, corners of the frame member 21b, and are connected to the second section 13 described below. The outer shape of the frame member 21b is, for example, a rectangular ladder shape. The frame member 21b supports, for example, various devices mounted on the first section 11.

[0018] The first section 11 includes, for example, two mechanical arms 23, four first thrusters 25a and two second thrusters 25b, a camera system 27a and a sensor 27b, one front control unit 29a and two rear control units 29b.

[0019] The base ends of the two mechanical arms 23 are fixed to the left and right corners of the front of the frame member 21b. Each mechanical arm 23 is, for example, a manipulator and includes a hinge (joint) driven by an actuator and multiple beams (links) connected by the hinges (joints). Each mechanical arm 23 includes, for example, an end effector (hand) 23a provided at the tip end thereof for performing various tasks such as grasping and moving an object. Each mechanical arm 23 includes, at the base end thereof, a power unit 23b that outputs power for operation. For example, when stopped, each mechanical arm 23 is disposed inside the left and right ends of the frame member 21b, and when operating, the tip end thereof protrudes outward (forward, etc.) from the robot 10.

[0020] The four first thrusters 25a are arranged, for example, two on each side at the front and rear of the frame member 21b, side by side. The two second thrusters 25b are arranged, for example, side by side on the left and right in the center of the frame member 21b in the front-rear direction. Each of the first thrusters 25a is a so-called azimuth thruster. Each of the first thrusters 25a includes, for example, a support that rotates around a first rotation axis along the vertical direction, and a propeller that is supported by the support and rotates around a second rotation axis that is perpendicular to the first rotation axis. Each of the first thrusters 25a generates, for example, a thrust in a direction perpendicular to the vertical direction. Each second thruster 25b includes, for example, a propeller that rotates around a rotation axis that is inclined at an acute angle with respect to the vertical direction. Each second thruster 25b generates, for example, thrust in directions that include at least the vertical direction.

[0021] The camera system 27a is disposed, for example, at the center in the left-right direction at the front of the frame member 21b. The camera system 27a includes, for example, a camera that captures images of the outside in front of the robot 10, and a plurality of lights that illuminate the outside in front of the robot 10. Sensor 27b is disposed, for example, below camera system 27a in the front of frame member 21b. Sensor 27b is, for example, a Doppler Velocity Log (DVL) that detects relative velocity based on emitting sound waves and detecting reflected and scattered waves.

[0022] One front control unit 29a is disposed, for example, at a position in front of the frame member 21b and behind the camera system 27a. The two rear control units 29b are arranged, for example, side by side on the left and right at the rear of the frame member 21b. Each of the control units 29a, 29b includes, for example, a box-shaped housing that seals the interior, and a power supply and an electronic control unit disposed inside the housing. Each of the control units 29a, 29b controls, for example, the operation of each of the mechanical arms 23, each of the thrusters 25a, 25b, the camera system 27a, the sensor 27b, and a drive unit 40 of the second portion 13 (described later).

[0023] Fig. 2 is an exploded perspective view showing the configuration of the second portion 13 of the robot 10 according to the embodiment. Fig. 3 is a plan view showing the configuration of the driving unit 40 of the robot 10 according to the embodiment. As shown in FIGS. 2 and 3, the second section 13 includes a cover member 30, a second skeleton F2 covered by the cover member 30, a moving member M, and a driving unit 40. The cover member 30 has an outer shape, for example, a rectangular box shape, and has a surface formed with a plurality of through holes that allow communication between the inside and the outside. The cover member 30 is fixed to the second skeleton F2.

[0024] The second framework F2 is fixed to the plurality of connecting members 21a of the first framework F1, and supports the cover member 30 and the drive unit 40, for example. The second skeleton F2 includes, for example, a lower frame 31D, and a front frame 31F and a rear frame 31R formed at the front and rear of the lower frame 31D. The lower frame 31D includes, for example, a front lower member 33D extending in the left-right direction, a left member 35L and a right member 35R extending in the front-to-rear direction, and a rear lower member 37D extending in the left-to-right direction, which are sequentially connected from front to rear. The front frame 31F includes, for example, a front lower member 33D, a front left member 33L and a front right member 33R extending in the up-to-down direction, and a front upper member 33U extending in the left-to-right direction, which are sequentially connected from bottom to top. The rear frame 31R includes, for example, a rear lower member 37D, a rear left member 37L and a rear right member 37R extending in the up-to-down direction, and a rear upper member 37U extending in the left-to-right direction, which are sequentially connected from bottom to top.

[0025] The movable member M includes, for example, a buoyant member Ma that generates buoyancy. The movable member M is moved by the drive unit 40 inside the cover member 30 in order to change at least one of the center of buoyancy and the center of gravity of the entire robot 10. The movable member M is moved to maintain or change the posture of the robot 10, for example, when the robot 10 is moving and when each mechanical arm 23 is operating.

[0026] The driving unit 40 includes, for example, two power sources 41 and a transmission mechanism 43. The power sources 41 are, for example, electric motors. The two power sources 41 are fixed, for example, to the left and right corners of the rear part of the lower frame 31D. The two power sources 41 supply power to the transmission mechanism 43 for moving the moving member M. It should be noted that the transmission mechanism 43 does not have to be fixed to, for example, the lower frame 31D.

[0027] FIG. 4 is a schematic diagram showing an example of the operation of the transmission mechanism 43 of the robot 10 according to the embodiment. 2, 3, and 4, the transmission mechanism 43 is a mechanism that moves the movable member M by two-dimensional translational motion in a two-dimensional Cartesian coordinate system of the X and Y axes. The transmission mechanism 43 is, for example, a so-called H-BOT or H-type gantry robot. The transmission mechanism 43 includes, for example, a ring-shaped member 45 arranged to form an H-shaped circular path having a first path portion 43a and a second path portion 43b arranged parallel to each other, and a third path portion 43c connected perpendicularly to each of the first path portion 43a and the second path portion 43b. For example, the first path portion 43a and the second path portion 43b are provided so as to reciprocate in parallel in the front-rear direction, and the third path portion 43c is provided so as to reciprocate in parallel in the left-right direction. The annular member 45 is, for example, a serpentine belt formed by a so-called endless circular belt. The annular member 45 is arranged, for example, to meander along a circular path on the same plane (for example, the same XY plane).

[0028] The transmission mechanism 43 includes, for example, two pairs of a drive pulley 47a and a driven pulley 47b, four bend pulleys 47c, two pulley support portions 47d, and a support member 49. For example, the two sets of drive pulleys 47a and driven pulleys 47b are one set of drive pulleys 47a and driven pulleys 47b fixed to both ends of the first path portion 43a and having an annular member 45 attached thereto, and another set of drive pulleys 47a and driven pulleys 47b fixed to both ends of the second path portion 43b and having an annular member 45 attached thereto.

[0029] The rotation axes of the drive pulley 47a and the driven pulley 47b are parallel to the Z-axis direction. For example, the drive pulley 47a and the driven pulley 47b reverse the direction of the annular member 45 by folding back and forth along the front-to-rear direction. The rotation axis of each drive pulley 47a is connected to the output shaft of each power source 41. Each drive pulley 47a is driven to rotate around its rotation axis by the power of each power source 41. Each drive pulley 47a transmits the power of each power source 41 to the annular member 45, thereby driving the annular member 45 along each path portion 43a, 43b, 43c. Each driven pulley 47b rotates around its rotation axis by the power transmitted from the annular member 45.

[0030] For example, the four bend pulleys 47c include two bend pulleys 47c arranged side by side in the front-rear direction between the first path portion 43a and the third path portion 43c and fitted with the annular members 45, and two bend pulleys 47c arranged side by side in the front-rear direction between the second path portion 43b and the third path portion 43c and fitted with the annular members 45. The rotation axis of each bend pulley 47c is parallel to the Z-axis direction. Each bend pulley 47c, for example, changes the direction of the annular member 45 between the front-rear direction and the left-right direction, in an orthogonal direction.

[0031] For example, the two pulley support portions 47d are one pulley support portion 47d that supports two bend pulleys 47c lined up at a predetermined interval in the front-to-back direction on the first path portion 43a side, and one pulley support portion 47d that supports two bend pulleys 47c lined up at a predetermined interval in the front-to-back direction on the second path portion 43b side.

[0032] For example, the power transmitted from the annular member 45 to the four bend pulleys 47c drives the four bend pulleys 47c and the two pulley support portions 47d in a first operating state, a second operating state, or a third operating state. For example, the first operating state is a state in which the two drive pulleys 47a rotate in different directions, and the rotation of each of the four bend pulleys 47c around its respective rotation axis is stopped, while the two pulley support portions 47d move along the front-to-rear direction together with the four bend pulleys 47c. For example, the second operating state is a state in which the two drive pulleys 47a rotate in the same direction, and the positions of the two pulley support portions 47d in the front-to-rear direction are kept constant, while each of the four bend pulleys 47c rotates around its respective rotation axis. For example, the third operating state is a state in which only one of the two drive pulleys 47a rotates, causing each of the four bend pulleys 47c to rotate around its respective rotation axis, while the two pulley support portions 47d move in the forward and backward directions together with the four bend pulleys 47c.

[0033] The support member 49 is fixed to a single portion of the annular member 45 (that is, only one of the outward path and the return path) in the third path portion 43c, for example, and supports the moving member M. For example, the support member 49 moves in the front-rear direction in the first operating state, moves in the left-right direction in the second operating state, and moves in a diagonal direction relative to both the front-rear direction and the left-right direction in the third operating state by the power of each power source 41 transmitted via the annular member 45. For example, the support member 49 moves forward in the front-rear direction in the first operating state shown in FIG. 4, and moves toward the right in the left-right direction in the second operating state shown in FIG. 4. For example, the support member 49 moves diagonally forward to the right in the third operating state in which only the drive pulley 47a of the second path portion 43b is stopped in the first operating state or the second operating state shown in FIG. 4.

[0034] As described above, according to the robot 10 of the embodiment, the power source 41 is fixed, so there is no need to reserve space required for the movement of, for example, signal lines and power lines connected to the power source 41, and the movable member M and buoyant member Ma can be made larger to facilitate control of the center of buoyancy and center of gravity. Furthermore, because the power source 41 does not move together with the movable member M and buoyant member Ma, fluctuations in the center of buoyancy and center of gravity can be suppressed, improving the ease of control of the center of buoyancy and center of gravity. For example, when moving a unit whose buoyancy is greater than its weight, the greater the buoyancy is relative to the weight, the less movement the float needs to make, so that it is possible to ensure responsiveness, such as quickly returning the vehicle to its original or desired attitude in response to disturbances such as currents that tilt the vehicle. In other words, it is more preferable to provide the moving member M with a buoyant member Ma that does not constitute a heavy object, and to fix the drive units, such as the power source 41 and transmission mechanism 43, which are heavy objects.

[0035] By providing the cover member 30, it is possible to reduce the torque capacity of the drive unit 40 and prevent difficulty in performing posture control, even in adverse environments such as when the relative flow of water becomes high speed due to water currents such as ocean currents and tidal currents or the motion state of the robot 10, or when there are many obstacles. Furthermore, it is possible to suppress an increase in the fluid resistance of the moving member M and the drive unit 40, suppress an increase in the power required to drive the moving member M and the drive unit 40, and suppress an increase in the size of the power source and power source 41.

[0036] In the transmission mechanism 43 using a so-called H-BOT or H-type gantry robot, the annular members 45 are arranged in a serpentine circular path on the same plane, so that the increase in space required for arranging the transmission mechanism 43 can be suppressed compared to when the annular members 45 are arranged stacked in two stages in the Z-axis direction, for example. Since the reduction in space for the movement of the movable member M can be suppressed, for example, by positioning the movable member M and the drive unit 40 at the rear side in response to fluctuations in the center of buoyancy and center of gravity due to the operation of each mechanical arm 23 at the front of the robot 10, the amount of movement of the movable member M in the fore-and-aft direction can be increased, and the ease of control of the center of buoyancy and center of gravity can be improved.

[0037] (Variation) Modifications of the embodiment will be described below. Note that the same parts as those in the above-described embodiment will be denoted by the same reference numerals, and descriptions thereof will be omitted or simplified. In the above-described embodiment, the transmission mechanism 43 that performs two-dimensional translational motion is a so-called H-BOT or an H-type gantry robot, but is not limited to this. For example, the transmission mechanism 43 may be a mechanism that includes a power source that is fixed to at least the second frame F2, that is, a power source that does not move along the power transmission path during power transmission. For example, a transmission mechanism that includes a power source that is fixed to something other than an H-BOT may be a transmission mechanism such as a so-called CoreXY or a so-called T-BOT. The so-called CoreXY transmission mechanism includes, for example, a first belt driven by a first power source for the X axis and a second belt driven by a second power source for the Y axis. The first and second belts are arranged in two stages so that they intersect with each other at different positions in the Z axis direction. The transmission mechanism of the so-called T-BOT includes, for example, one belt driven by two power sources, a support member that moves in the Y-axis direction by the power transmitted from the belt, a guide member that guides the movement of the support member in the Y-axis direction, and an arm member that is supported and guided by the support member and moves in the X-axis direction by the power transmitted from the belt. The guide member of the support member and the arm member are arranged in two stages so that their positions in the Z-axis direction are different from each other.

[0038] The embodiments of the present invention are presented as examples and are not intended to limit the scope of the invention. These embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are intended to be included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0039] 10...robot, 11...first part, 13...second part, 23...mechanical arm, 25a...first thruster, 25b...second thruster, 27a...camera system, 27b...sensor, 29a...front control unit, 29b...rear control unit, 30...cover member, 40...drive unit, 41...power source, 43...transmission mechanism, 47a...drive pulley, 47b...driven pulley, 47c...bend pulley, 47d...pulley support, 49...support member, F1...first skeleton, M...moving member, Ma...buoyancy member.

Claims

1. a first portion and a second portion coupled to each other; The second portion is a moving member that is moved to change at least one of the center of buoyancy and the center of gravity of the first portion and the second portion as a whole; a drive unit that moves the moving member by two-dimensional translational motion; Equipped with The drive unit is a power source that outputs power for moving the moving member and is fixed to the first portion; robot.

2. The moving member includes a buoyant member that generates buoyancy. The robot of claim 1 .

3. The second portion is a cover member for covering the entire moving member and the driving unit; The robot according to claim 2.

4. The drive unit is a transmission mechanism that transmits the power output from the power source to the moving member, The transmission mechanism includes: an annular member arranged to form an H-shaped circular path having a first path portion and a second path portion arranged parallel to each other and a third path portion connected perpendicularly to each of the first path portion and the second path portion; two sets of a drive pulley and a driven pulley, each fixed to both ends of the first path portion and the second path portion, to which the annular member is attached; four bend pulleys, each of which has the annular member mounted between the first path portion and the third path portion and between the second path portion and the third path portion, and which move along the first path portion and the second path portion; a support member that is fixed to a single portion of the annular member in the third path portion, supports the moving member, and moves along each of the first path portion and the second path portion or the third path portion; Equipped with The robot according to any one of claims 1 to 3.

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