Mobile

Abstract

To provide a movable body which can move in multiple directions, getting over a step unlike conventional movable bodies.SOLUTION: A movable body comprises: a chassis 2; at least three arms which are arranged to be aligned in a circumferential direction around the chassis 2 in plan view, are rotatable vertically around an arm rotary shaft, and are supported with respect to the chassis 2 so as to protrude outward from an outer peripheral face of the chassis 2; arm rotation parts 71 each of which is provided to correspond to each of the at least three arms, and rotates one arm with respect to the chassis 2; wheels 50 each of which is supported by the arm, at a position separated outward from the outer peripheral face of the chassis 2, in each of the three arms; and a movement mechanism 60 for moving the movable body 1 using the corresponding wheel 50. As configured to be movable in multiple directions according to a state that the movement mechanism 60 drives the wheel 50, the movable body 1 can move in multiple directions, getting over a step.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a mobile body having a plurality of wheels and capable of moving in multiple directions. [Background technology]

[0002] Conventionally, mobile bodies having multiple wheels and used for various purposes have been proposed. For example, such mobile body configurations may be used in autonomously moving robots. In order for such mobile bodies to travel on uneven ground, they require a mechanism for overcoming obstacles such as steps.

[0003] As a moving body configured to overcome a step, there is one in which a drive mechanism for a wheel is raised and lowered using an arm that supports the wheel (see, for example, Patent Document 1 below).

[0004] It should be noted that there is also known a device in which a plurality of moving parts, each of which has a support shaft that can reciprocate, is provided below the base (see, for example, Patent Document 2 below). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2018-535875 [Patent Document 2] Japanese Patent Application Publication No. 2018-188013 Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, a moving body using wheels, such as that described in Patent Document 1, is configured to be able to overcome steps only in a predetermined direction corresponding to the orientation of the wheels. However, such moving bodies may be required to be able to perform precise positioning of the moving body itself and to be able to maneuver in a small radius. To meet such needs, it is desirable for the moving body to have a configuration that allows it to move and overcome steps in multiple directions.

[0007] For example, a mobile body such as that described in Patent Document 2 can move in all directions and overcome obstacles in all directions, but it has six or more moving parts and has a complex overall structure.

[0008] An object of the present invention is to provide a moving body that can be simply configured and can move over steps in multiple directions. [Means for solving the problem]

[0009] The mobile body of the first invention comprises a chassis, at least three arms arranged in a circumferential direction around the chassis in a plan view, each of which is rotatable up and down around an arm rotation axis and is supported on the chassis so as to protrude outward from the outer circumferential surface of the chassis, an arm rotation unit corresponding to each of the at least three arms and capable of rotating one arm relative to the chassis, wheels supported by the arms at a position spaced outward from the outer circumferential surface of the chassis on each of the three arms, and a moving mechanism corresponding to the wheels and which moves the mobile body using the corresponding wheel, and is configured to be movable in multiple directions depending on the drive state of the wheels by the moving mechanism.

[0010] With this simple configuration, it is possible to make it possible to move over steps in multiple directions.

[0011] Furthermore, the moving body of the second invention is a moving body in which, compared to the first invention, the moving mechanism has a drive actuator that rotates the corresponding wheel around the axle and a steering actuator that steers the corresponding wheel, and the wheel corresponding to the moving mechanism is supported on an arm so that it can be steered.

[0012] With this configuration, the moving body can be reliably moved in multiple directions.

[0013] Furthermore, the moving body of the third invention is a moving body in which, in contrast to the first or second invention, the wheels corresponding to the moving mechanism are omni-wheels.

[0014] With this configuration, the moving body can be configured to be movable in multiple directions using a small number of actuators.

[0015] Furthermore, the moving body of the fourth invention is a moving body according to any one of the first to third inventions, further comprising at least one training wheel arranged so as to be positioned between the chassis and the road surface.

[0016] With this configuration, the chassis posture can be easily maintained.

[0017] Furthermore, the movable body of the fifth invention is a movable body in which, compared to any of the first to fourth inventions, the arm rotation axis of each of the three arms is approximately horizontal and is arranged so as to form an angle of approximately 60 degrees with the arm rotation axes of the other two arms in a planar view, a straight line that is perpendicular to the arm rotation axis of each of the three arms and passes through the wheels in a planar view is configured to pass through a common point, and the wheels supported by each of the three arms are on a circumference centered at a common point in a planar view.

[0018] With this configuration, the operation of the arm rotation unit and the movement mechanism according to the direction in which the moving body is moved or the position of the step can be easily defined regardless of the orientation of the moving body, using a simple device configuration. [Effects of the Invention]

[0019] The moving body according to the present invention can be simply configured and is capable of moving over steps in multiple directions. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a perspective view showing a configuration of a moving body according to an example of the present embodiment; [Figure 2] Plan view of the same vehicle [Figure 3] FIG. 10 is a diagram showing an example of the moving object's operation of climbing over a step. [Figure 4] FIG. 10 is a perspective view showing the configuration of a moving body according to a first modified example of the present embodiment; [Figure 5] FIG. 10 is a perspective view showing the configuration of a moving body according to a second modification of the present embodiment. [Figure 6] FIG. 2 is a plan view showing the configuration of the moving body; [Figure 7] FIG. 11 is a plan view showing the configuration of an arm used in a moving body according to a third modification of the present embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, embodiments of a moving body and the like will be described with reference to the drawings. Note that components with the same reference numerals in the embodiments perform similar operations, and therefore repeated description may be omitted.

[0022] In the following, for the convenience of explaining the structure of the moving body, directions may be indicated based on the state in which the moving body is in contact with a horizontal road surface. That is, the direction perpendicular to the road surface may be referred to as the up-down direction. Furthermore, the direction passing through the center of the moving body (not necessarily the exact center) in a plan view may be referred to as the radial direction. The direction along an arc centered on the center of the moving body may be referred to as the circumferential direction. The indication of each direction in this manner is done solely for the convenience of explanation and does not limit the orientation, posture, etc. of the moving body of the present invention when in use.

[0023] (Embodiment)

[0024] In this embodiment, the moving body has three sets of arms, each of which has wheels equipped with a steering mechanism attached, that protrude outward from the outer circumferential surface of the chassis. Each arm is supported so as to be rotatable up and down around an arm rotation axis. This configuration allows the moving body to overcome steps from multiple directions. The moving body can move in all directions using the steering mechanism. Note that in this embodiment, the wheels may be omniwheels, in which case a steering mechanism may not be provided. A moving body 1 configured in this manner will be described below.

[0025] Fig. 1 is a perspective view showing the configuration of a moving body 1 according to an example of the present embodiment, and Fig. 2 is a plan view of the moving body 1.

[0026] In the following description, illustrations of the detailed configuration of the moving body 1 are omitted. For example, the structure of the chassis 2 other than the portion related to the suspension of the wheels may be set appropriately depending on the use of the moving body 1. In addition, in Fig. 2, the dashed dotted line indicates the arm rotation axis, a straight line perpendicular to the arm rotation axis and passing through the wheels, or a circumference T centered at the center C.

[0027] The moving body 1 comprises a chassis 2, three arms 11, 21, 31 (hereinafter, these may be collectively referred to as arms 10 without distinction), three wheels 51, 52, 53 (hereinafter, these may be collectively referred to as wheels 50 without distinction), a moving mechanism 60, an arm rotation unit 71, and three training wheels 81.

[0028] The mobile object 1 is typically placed on a substantially flat road surface R (shown in FIG. 3 ) and is capable of moving on the road surface R. The mobile object 1 includes, for example, a control unit (not shown) mounted on the chassis 2 (which may be configured, for example, by a computer or an electric circuit), a sensor unit for detecting the surrounding conditions, and a battery used as a power source for each unit. The mobile object 1 is configured to be able to autonomously move in multiple directions on the road surface R based on, for example, a predetermined program, detection results by the sensor unit, instructions received from the outside, and the like. Here, being able to move in multiple directions means being able to move in various directions, such as forward, backward, left, right, and diagonally, while maintaining the orientation of the chassis 2 in a predetermined direction. Note that the mobile object 1 is not limited to being able to move autonomously. For example, the mobile object 1 may be able to move on the road surface R by configuring various actuators to function based on a preset program, sequence, or the like. Alternatively, the mobile object 1 may be able to move on the road surface R by receiving instructions from the outside to operate each actuator.

[0029] The chassis 2 may be said to be the main body of the moving body 1, or may be said to be the frame of the moving body 1. In this embodiment, the chassis 2 is configured, for example, to have a polygonal shape in a plan view. In a plan view, the chassis 2 has a shape that can be roughly described as a triangle. More specifically, the side surfaces to which the three arms 10 are attached form an angle of roughly 60 degrees, as will be described later. The chassis 2 may have a shape that is partially or entirely rounded.

[0030] The arm 10 is, for example, a beam-like member that is linear in plan view. The arm 10 is disposed radially outward of the chassis 2 so that its longitudinal direction is substantially horizontal under normal conditions (for example, when moving on a horizontal road surface). In plan view, the arms 11, 21, and 31 are disposed in the circumferential direction around the chassis 2 in this order in a clockwise direction. In this embodiment, the three arms 10 are configured so that their longitudinal lengths are substantially the same. Furthermore, each of the three arms 10 is disposed so that it forms an angle of approximately 120 degrees with the other two arms 10 in plan view. That is, in plan view, the angle between the arm 11 and the arm 21, the angle between the arm 21 and the arm 31, and the angle between the arm 31 and the arm 21 are all configured so that they are approximately 120 degrees. The three arms 10 are disposed on three side portions of the chassis 2 that roughly form a triangle in plan view as described above. In this embodiment, the arms 10 are supported by the chassis 2 so as to protrude outward from the outer circumferential surface of the chassis 2. That is, the arms 10 are provided so that their longitudinal direction is the direction in which they protrude radially outward from the outer circumferential surface of the chassis 2, i.e., the radial direction. However, the length of each arm 10, its relative positions, the direction in which they protrude outward from the chassis 2, and the like are not limited to this.

[0031] The arm 10 may have a shape other than a straight line, such as being curved or being a member configured in a plate shape or A-shape in a plan view.

[0032] Furthermore, in this embodiment, each arm 10 is supported relative to the chassis 2 so as to be rotatable about an arm rotation axis (in this embodiment, the rotation axis of an arm rotation unit 71 described below). In this embodiment, the arm rotation axis passes near the radially inner end of each arm 10. The arm rotation axis is an axis disposed approximately horizontally. The arm 10 is rotatable up and down relative to the chassis 2 about the arm rotation axis from a state in which the longitudinal direction is approximately horizontal. In other words, the arm 10 is rotatable relative to the chassis 2 about the arm rotation axis so that a portion away from the arm rotation axis is displaced up and down.

[0033] In this embodiment, in a plan view, the arm rotation axis of each of the three arms 10 is approximately perpendicular to the longitudinal direction of the respective arm 10. Each arm rotation axis is disposed so as to form an angle of approximately 60 degrees with the arm rotation axes of the other two arms 10 in a plan view. Furthermore, in a plan view, a line perpendicular to the arm rotation axis of each of the three arms 10 and passing through a wheel 50 (described later) is configured to pass through a common point. Note that "each arm rotation axis passing through a common point" can be interpreted roughly, and is an expression that allows for a state in which the intersections of the lines of two arms 10 are offset from each other in the strict sense. That is, in this embodiment, the three arms 10 are disposed so as to be spaced apart from each other at equal intervals of 120 degrees from the center of the chassis 2 (the area indicated by the hatched area C in FIG. 2 ) in the circumferential direction. The three arms 10 are disposed so as to protrude radially from the chassis 2 as viewed from the center of the chassis 2.

[0034] The wheels 50 are provided on each of the three arms 10 at positions spaced outward from the outer peripheral surface of the chassis 2. In this embodiment, one wheel 50 is supported near the radially outer end (tip) of each of the three arms 10.

[0035] More specifically, a wheel 51 is disposed at the tip of the arm 11, a wheel 52 is disposed at the tip of the arm 21, and a wheel 53 is disposed at the tip of the arm 31. The wheels 51, 52, and 53 are disposed so as to line up in this order in a clockwise direction throughout the entire moving body 1. The distance between each wheel 50 and the center of the chassis 2 is roughly equal. In other words, the wheels 50 supported by each of the three arms 10 are on a circumference T centered at a common point. Note that the positions of the wheels 50 are not limited to this and may be changed depending on the length of the arms 10, the number of arms 10, and the shape of the chassis 2. Furthermore, two or more wheels 50 may be provided for each arm 10, or a different wheel may be provided in addition to one wheel 50.

[0036] A movement mechanism 60 is provided corresponding to each wheel 50 of the three arms 10. That is, each of the three wheels 50 is driven by a movement mechanism 60. The movement mechanisms 60 are configured to move the moving body 1 using the corresponding wheel 50. For example, a control unit controls the operation of each movement mechanism 60, thereby moving the moving body 1. Furthermore, for example, the moving body 1 may be movable by each movement mechanism 60 being driven in response to an external command.

[0037] In this embodiment, the movement mechanism 60 has a drive actuator 61 and a steering actuator 63 .

[0038] The drive actuator 61 rotates the corresponding wheel 50 around the axle. The drive actuator 61 is, for example, any of various motors. The drive actuator 61 may have a detection means such as an encoder that can detect the number of rotations of the wheel 50, i.e., the number of rotations of the axle, or may be a motor that can control the rotation angle, such as a stepping motor. The drive actuator 61 may also be configured to include a motor that serves as a drive source and a transmission mechanism (for example, one that uses gears, etc.) that transmits the torque of the motor to the axle. The drive actuator 61 may also have a clutch so that the wheel 50 can rotate freely.

[0039] The steering actuator 63 steers the corresponding wheel 50 by rotating it around a steering shaft (not shown). That is, in this embodiment, the wheel 50 corresponding to the moving mechanism 60 is supported on the arm 10 so as to be steerable. The steering shaft is, for example, oriented approximately perpendicular to the horizontal plane. The steering actuator 63 is an actuator capable of controlling the rotation angle. The steering actuator 63 is, for example, a servo motor or a stepping motor, but is not limited to these, and may be an actuator such as a motor equipped with an encoder or the like so as to be able to control the rotation angle. Furthermore, the steering actuator 63 may have a clutch so that the wheel 50 can freely rotate around the steering shaft.

[0040] In this embodiment, all of the wheels 50 are rotatable by the drive actuators 61 and steerable by the steering actuators 63. Depending on the drive state of each wheel 50 by each movement mechanism 60 (rotation around the axle or rotation around the steering axis), the moving body 1 can move in multiple directions.

[0041] The arm rotation units 71 are provided to correspond to at least three arms 10, respectively. Each arm rotation unit 71 is configured to rotate one arm 10 around the arm rotation unit 71 relative to the chassis 2. For example, the control unit controls the operation of the arm rotation unit 71, causing the corresponding arm 10 to rotate. Alternatively, for example, the arm rotation unit 71 may be driven in response to an external command, causing the corresponding arm 10 to rotate.

[0042] The arm rotation unit 71 is an actuator capable of controlling the rotation angle. The arm rotation unit 71 is, for example, a servo motor or a stepping motor, but is not limited to these. For example, the arm rotation unit 71 may be an actuator such as a motor equipped with an encoder or the like and configured to be able to control the rotation angle. The arm rotation unit 71 may also be one that rotates the arm 10 using a hydraulic actuator. The arm rotation unit 71 may also be configured to include a support shaft that rotatably supports the arm 10 with respect to the chassis 2, and a linear actuator that is arranged between a part of the arm 10 and the chassis 2 and changes the distance therebetween.

[0043] The training wheels 81 are arranged so as to be located between the chassis 2 and the road surface R. In this embodiment, the training wheels 81 are arranged on the surface of the chassis 2 that faces the road surface R. The training wheels 81 may be configured to be rotatable around a vertical axis depending on the direction of movement of the movable body 1, for example, like so-called swivel casters, but are not limited to this. In this embodiment, three training wheels 81 are provided. The three training wheels 81 are arranged on a line that is perpendicular to each arm rotation axis and passes through the center of the chassis 2. As a result, the movable body 1 is configured so that the chassis 2 is stably supported by the one or more training wheels 81 even in a state in which one or more wheels 50 are separated from the road surface R or the like. Note that the number and positions of the training wheels 81 are not limited to this and may be one, two, or four or more.

[0044] As described above, in the moving body 1, the arms 10, each having a wheel 50 attached to its tip, are arranged to protrude radially from the chassis 2, and each wheel 50 can be operated by the movement mechanism 60, so that the moving body 1 can move in multiple directions and overcome steps in those directions. In addition, the posture of the chassis 2 can be adjusted by rotating the three arms 10 relative to the chassis 2 while the wheels 50 are in contact with the ground. Therefore, it is possible to easily meet the need for transportation with a stable posture, for example.

[0045] When climbing over a step in the movement direction, for example, the arm 10 may be rotated relative to the chassis 2 as follows.

[0046] In this embodiment, the moving body 1 can rotate the arms 10 relative to the chassis 2 by the arm rotation unit 71, thereby displacing the wheels 50 supported by the arms 10 up and down relative to the chassis 2. When at least one arm 10 rotates upward, the wheels 50 supported by the arms 10 move upward (float) above the road surface R. When one or more arms 10 rotate downward, the chassis 2 is lifted upward above the road surface R.

[0047] For example, in this embodiment, the arms 10 of the moving body 1 rotate upward, causing the floating wheels 50 to move closer to the step, placing the wheels 50 on the step. Furthermore, the arms 10 of the moving body 1 rotate downward, causing the floating wheels 50 to land below the step as they move over a step that is lower in the moving direction. In response to this, the arms 10 of the moving body 1 rotate up and down, causing the chassis 2 to rise or fall. Depending on the moving direction of the moving body 1 and the position of the step, the arms 10 to be rotated and their rotation direction are changed as appropriate, thereby performing a series of operations to overcome the step. This allows the moving body 1 to move in multiple directions and overcome the step.

[0048] FIG. 3 is a diagram showing an example of the moving body 1 climbing over a step.

[0049] FIG. 3 is a side view showing a scene in which a moving object 1 on a road surface R climbs over a step B on the road surface R.

[0050] Assume that the moving body 1 moves toward a step B. In this case, the step B has an upper surface that is higher than the road surface R on which the moving body 1 is placed. The step between the road surface R and the step B is sufficiently wide.

[0051] The orientation of the moving body 1 is such that the wheels 53 are positioned at the front in the direction of movement (to the right on the paper in FIG. 3). In this case, the moving body 1 operates, for example, to follow steps S1 to S9 shown in FIG.

[0052] First, the moving body 1 moves to just before the step B (S1). Then, the arm 31 rotates upward relative to the chassis 2. In this case, the wheels 53 are lifted off the road surface. In other words, from a state in which all of the wheels 50 are substantially in contact with the road surface R, the arm 31, which is in the front in the direction of movement, rotates upward in the rotation direction. As a result, the posture of the chassis 2 is maintained by the wheels 51, 52 and the auxiliary wheel 81, and the wheels 53 move upward away from the surface R.

[0053] Next, the moving body 1 moves in the direction of travel, and after the lifted wheels 53 come onto the step B, the arms 31 rotate and the wheels 53 touch the step B (S2). Then, the arms 10 rotate downward, causing the chassis 2 to rise, and the moving body 1 moves so that the training wheels 81 rest on the upper surface of the step B (S3). As the moving body 1 moves further in the direction of travel (S4), the arms 11 and 21 rotate upward, lifting the wheels 51 and 52, and the chassis 2 is supported by the training wheels 81 and the wheels 53. As the moving body 1 moves further in the direction of travel and the arms 11 and 21 rotate vertically, all the wheels 50 touch the upper surface of the step B (S5). In this case, it is desirable that the training wheels 81 are also in close proximity to the upper surface of the step B.

[0054] When the moving body 1 approaches a step in the direction of travel that extends downward from the tip of the step B to the road surface R, the wheel 53 protrudes from the step B above the road surface R, and the chassis 2 is supported by the auxiliary wheel 81 and the wheels 51, 52. At this point, the arm 31 rotates downward relative to the chassis 2, and the wheel 53 comes into contact with the road surface R. As the moving body 1 moves in the direction of travel, the wheel 50 causes the chassis 2 to be lifted off the road surface R and the step B (S7).

[0055] Thereafter, as the moving body 1 advances in the direction of movement and the safety wheels 81 leave the top of the step B, the arms 10 rotate upward, causing the chassis 2 to descend, and the safety wheels 81 and wheels 53 come into contact with the road surface R (S8). As the moving body 1 advances further in the direction of movement and the wheels 51, 52 clear the step B, the arms 11 and 21 rotate downward relative to the chassis 2, causing the wheels 51, 52 to come into contact with the road surface R (S9). In this way, the moving body 1 can climb over the step B.

[0056] The direction of approaching the step is not limited to the direction described with reference to Fig. 3. For example, by rotating one or more arms 10 relative to the chassis 2 in a different manner, one of the wheels 50 may be raised or the chassis 2 may be raised or lowered, thereby enabling the step to be overcome. In this embodiment, the three arms 30 are arranged in different directions from each other in a plan view, and therefore the operation of the arm rotation unit 71 and the movement mechanism 60 for moving over the step can be easily determined depending on the direction in which the moving body 1 moves or the position of the step, regardless of the direction of the moving body 1.

[0057] In this embodiment, as the arm 10 rotates and the wheels 50 rise or fall relative to the chassis 2, the steering actuator 63 and the steering shaft tilt relative to the chassis 2. In order to reduce the load on the steering actuator 63 and the steering shaft due to this tilt, it is preferable to keep the rotation angle of the arm 10 within a predetermined angle (for example, within 10 degrees). A limiting member may be provided to limit the rotation angle of the arm 10.

[0058] The configuration of the moving body is not limited to that of the above-described embodiment, and modifications of this embodiment will be described below.

[0059] Variation 1 is as follows. That is, omni-wheels may be used as wheels, and the moving body may be able to move in multiple directions by the drive mode of multiple omni-wheels. In this case, the moving mechanism 60 does not need to use a steering actuator 63 for steering the wheels. That is, the moving mechanism 60 only needs to be provided with at least a drive actuator 61 for rotating the wheels.

[0060] FIG. 4 is a perspective view showing the configuration of a moving body 201 according to the first modification of the present embodiment.

[0061] The moving body 201 according to the first modification is different from the moving body 1 according to the above-described embodiment in that all of the wheels 251, 252, 253 are omni-wheels, and only a drive actuator 61 is provided as a movement mechanism corresponding to the wheels. That is, one wheel 251, 252, 253 is attached to each arm 10. Note that the axles of the wheels 251, 252, 253 are substantially perpendicular to the arm rotation axis, but may be oriented in a different direction.

[0062] According to this modification, by rotating each arm 10 relative to the chassis 2, it is possible to overcome steps in the same manner as described above. In addition, by driving the wheels 251, 252, and 253, it is possible to move the moving body 1 in multiple directions. Since the moving body 201 does not have a steering actuator 63, it is possible to simplify the configuration of the moving body 201.

[0063] Modification 2 is as follows: That is, each of the seesaw-shaped arms, one end of which is located below the chassis, may be configured to have at least one wheel or auxiliary wheel on each side of the center of rotation of the arm.

[0064] Fig. 5 is a perspective view showing the configuration of a moving body 301 according to Modification 2 of the present embodiment, and Fig. 6 is a plan view showing the configuration of the moving body 301.

[0065] The moving body 301 according to the second modification differs from the moving body 1 in that, instead of each of the three arms 10 described above, arms 310 (arms 311, 321, 331) are used, each supported so that the arm rotation axis passes through the approximate center in the longitudinal direction. Each arm 310 is rotatably supported with respect to the chassis 2 by the arm rotation axis located in the same position as in the above embodiment. In a plan view, the arms 310 are arranged at approximately equal intervals in the circumferential direction so as to radiate from the center of the chassis 2. The outer tip of each arm 310 is located away from the chassis 2 and outward, and the inner tip of each arm 310 is located below the chassis 2.

[0066] When viewed from the direction along the arm rotation axis, each arm 310 has a shape that is bent downward from the center through which the arm rotation axis passes toward the end. Therefore, each arm 310 can rotate up and down within a predetermined rotation range without the inner tip end interfering with the chassis 2. In other words, when each arm 310 rotates so that the outer tip end is displaced upward, the inner tip end is displaced downward.

[0067] In this embodiment, a wheel 50 is supported at the outer tip of each arm 310. Each wheel 50 can be rotated around an axle or a steering axis by a movement mechanism 60. In other words, the movement mechanism 60 can move the moving body 301 in multiple directions using the corresponding wheel 50.

[0068] Further, auxiliary wheels 381 are provided at the inner tip of each arm 310. The auxiliary wheels 381 are, for example, swivel casters, but are not limited to this. Note that wheels 50 driven by the movement mechanism 60 may also be supported at the inner tip.

[0069] Here, in the mobile body 301, by rotating each arm 310, it is possible to lift the wheel 50 closest to an ascending step off the road surface so that the step can be overcome, or to bring the wheel 50 closest to a descending step into contact with the road surface so that the step can be overcome smoothly. For example, by rotating each arm 310 relative to the chassis 2, it is possible to overcome a step while maintaining a state in which one of the wheels 50 or the auxiliary wheels 381 of each arm 310 is in contact with the road surface.

[0070] Modification 3 is as follows: That is, each arm may be supported by a link mechanism such as a parallel link mechanism so that the position of each wheel can be displaced in the vertical direction.

[0071] FIG. 7 is a plan view showing the configuration of an arm 210 used in a moving body according to a third modification of the present embodiment.

[0072] In the third modification, the arm 210 is made up of a first link 211, a second link 212 that is substantially parallel to the first link 211, and a support member 215 that supports the wheel 50. The tip of the first link 211 and the tip of the second link 212 are attached to the support member 215, thereby forming a parallel link mechanism. The wheel 50 is supported by the support member 215 together with the drive actuator 61, the steering actuator 63, and the steering shaft 64. At least one of the first link 211 and the second link 212 is rotatable about an arm rotation shaft relative to the chassis 2 by an arm rotation unit 71.

[0073] The arm 210 is configured so that the support member 215 is displaced to the upper limit while maintaining its posture as the first link 211 and the second link 212 rotate relative to the chassis 2. In this way, the angle of the steering shaft 64 of the wheel 50 does not change before and after the arm 210 rotates. Therefore, even if the rotation angle of the arm 210 increases, it is possible to prevent the load on the steering shaft 64, the steering actuator 63, etc. from increasing.

[0074] (others)

[0075] The present invention is not limited to the above-described embodiment, and various modifications are possible, and these modifications are also included within the scope of the present invention.

[0076] For example, training wheels may not necessarily be provided. For example, in the above-described embodiment, a contact portion may be provided on the surface of the chassis facing the road surface, which is configured to contact the road surface instead of the wheel when one or more arms rotate upward. In this case, the contact portion may have, for example, a spherical member rotatably held on the chassis, or may be fixed to the chassis and provided so as to slide against the road surface. It is preferable that the contact portion be configured so as to have a small coefficient of friction with the road surface.

[0077] The number of arms is not limited to three, and four or more arms may be provided. In the above-described embodiment, three arms are arranged to form a Y-shape in a plan view, but this is not limiting. For example, four arms may be arranged around the chassis to form an X-shape in a plan view. Increasing the number of arms can improve stability during driving and stability when climbing over obstacles.

[0078] An embodiment may be configured by appropriately combining the respective configurations according to the above-described embodiments. For example, the configurations are not limited to those of the above-described embodiments, and each component of the above-described embodiments may be appropriately replaced or combined with a component of another embodiment. Furthermore, some components or functions may be omitted from the above-described embodiments.

[0079] The structure of the moving body as described above can be widely used, for example, as an undercarriage device for an indoor / outdoor transport robot or a mobile work robot with a robot arm. [Industrial Applicability]

[0080] As described above, the moving body according to the present invention can have a simple structure, can move over steps in multiple directions, and is useful as a moving body, etc. [Explanation of symbols]

[0081] 1,201,301 Mobile body, 2 Chassis, 10,11,21,31,210,310,311,321,331 Arm, 50,51,52,53,251,252,253 Wheel, 60 Moving mechanism, 61 Drive actuator, 63 Steering actuator, 71 Arm rotation part, 81 Training wheel, R Road surface

Claims

1. The chassis and three arms that are arranged in a circumferential direction around the chassis in a plan view, are rotatable up and down around arm rotation shafts, and are supported by the chassis so as to protrude outward from the outer circumferential surface of the chassis; an arm rotation unit provided to correspond to each of the three arms and capable of rotating one of the arms relative to the chassis; a wheel supported by each of the three arms at a position spaced outward from the outer circumferential surface of the chassis; Three auxiliary wheels arranged to be positioned between the chassis and a road surface; a movement mechanism provided to correspond to the wheels and configured to move the moving body using the corresponding wheels; the arm rotation axis of each of the three arms is substantially horizontal and is disposed so as to form an angle of approximately 60 degrees with the arm rotation axes of the other two arms in a plan view; In a plan view, a straight line that is perpendicular to the arm rotation axis and passes through the wheel for each of the three arms passes through a common point, In a plan view, the wheels supported by the three arms are located on a circumference having the common center at the same point, In a plan view, the three auxiliary wheels are respectively arranged on three straight lines that are perpendicular to the arm rotation axes of the three arms and pass through a central portion of the chassis, A moving body that can move in multiple directions depending on the drive state of the wheels by the moving mechanism, and is configured so that one or more of the auxiliary wheels contact the road surface even when one or more of the wheels are off the road surface.

2. The movement mechanism includes a drive actuator that rotates the corresponding wheel around an axle, and a steering actuator that steers the corresponding wheel, The moving body according to claim 1 , wherein a wheel corresponding to said moving mechanism is supported steerably relative to said arm.

3. The moving body according to claim 1 or 2, wherein the wheels corresponding to the moving mechanism are omni-wheels.

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