JP2023038072A - Movable body - Google Patents

Abstract

To provide a movable body capable of moving in a multi direction.To provide a movable body which can move in multiple directions, using a simplified structure unlike conventional movable bodies.SOLUTION: A movable body comprises: a chassis 2; at least three wheels 50 which are arranged to be aligned in a circumferential direction around the chassis 2; at least three drive actuators 61 which are provided so as to correspond to the wheels 50, respectively, and rotate the corresponding wheels 50 around axles, respectively; a steering actuator 64 for steering the wheels 50; a steering mechanism 65 which has an input member 161 moving according to operation of the steering actuator 64, and an output member 166 which is configured to be linked with displacement of the input member 161; and at least three transmission mechanisms 67 for rotating the corresponding wheel 50 around a steering axis, according to operation of the corresponding output member 166. As configured with the at least three wheels 50 being steered synchronously according to the operation of the steering actuator 64, the movable body 1 is movable in multi directions using a simplified structure.SELECTED DRAWING: Figure 1

Description

The present invention relates to a mobile body having a plurality of wheels and capable of moving in multiple directions.

Conventionally, there have been proposed configurations of mobile bodies having a plurality of wheels and used for various purposes. For example, such a configuration of a moving body may be used for a robot that can travel autonomously.

As the movable body configured to be movable in all directions, there are a plurality of moving parts in which a support shaft is configured to be able to reciprocate at the bottom of a base, as described in Patent Document 1 below, for example. Some are provided.

Patent Literature 2 listed below describes a configuration of a synchronous steering vehicle body that does not require a differential and aims to directly realize synchronous steering between the wheels and the driver's cab. In this synchronous steering vehicle body, gears or chains and sprockets are used to interlock a plurality of wheels with the driver's cab.

Patent Document 3 below describes a moving body configured to climb over a step by vertically moving a wheel drive mechanism using an arm that supports the wheel.

JP 2018-188013 A Japanese Patent Application Publication No. 2019-521914 Japanese Patent Publication No. 2018-535875

A moving body having a structure as described in Patent Document 1 and Patent Document 2 is movable in all directions, but has a complicated structure as a whole. In addition, a moving body using wheels as described in Patent Document 3 is movable in a predetermined direction according to the orientation of the wheels, and is movable in multiple directions with respect to the orientation of the chassis. not a thing

SUMMARY OF THE INVENTION An object of the present invention is to provide a moving body that can move in multiple directions using a simple configuration.

The moving body of the first aspect of the present invention is arranged along the chassis in a circumferential direction around the chassis in plan view, and is supported by the chassis via the support portion. at least three wheels rotatable about a steering axis relative to; at least three drive actuators associated with each of the wheels to rotate the corresponding wheels about their axles; a steering actuator for operating the steering mechanism; a steering mechanism having an input member that moves according to the operation of the steering actuator; and an output member configured to interlock with the operation of the input member; and at least three transmission mechanisms for rotating the corresponding wheels about the steering shaft according to the operation of the corresponding output members, and the wheels are synchronously steered according to the operations of the steering actuators. It is a moving object.

With such a configuration, it is possible to move in multiple directions with a simple configuration.

In contrast to the first invention, the moving bodies of the second invention are arranged in a circumferential direction around the chassis in a plan view, and are rotatable up and down, respectively. At least three arms supported on the chassis so as to protrude outward from the outer peripheral surface, and provided so as to correspond to each of the arms, and one arm can be rotated with respect to the chassis. and an arm rotating portion, the supporting portion is provided on each of the arms, and the wheel is a movable body supported by the arm at a position spaced outwardly from the outer peripheral surface of the chassis.

With such a configuration, it is possible to realize a moving body that can move over steps in multiple directions with a simple configuration.

In addition, in the moving body of the third invention, in contrast to the first or second invention, each of the arms includes a first link and a second link substantially parallel to the first link, and the support section comprises: A moving body connected to the first link and the second link so as to form a parallel link.

With such a configuration, a mobile body that can move over steps in multiple directions is realized with a simple configuration.

Further, in the moving body of the fourth invention, in contrast to any one of the first to third inventions, the steering mechanism comprises an input shaft that rotates according to the operation of the steering actuator and a rotation that rotates according to the rotation of the input shaft. each of the transmission mechanisms rotates according to the corresponding output shaft and transmits the torque of each output shaft as torque that rotates each of the at least three wheels about the steering axis. It is a mobile body that does.

With such a configuration, it is possible to secure a wide steerable range for each wheel.

In addition, the moving body of the fifth invention is the moving body, in which the transmission mechanism has a constant velocity joint, in contrast to any one of the first to fourth inventions.

With such a configuration, the steering of each wheel can be synchronously performed more reliably.

ADVANTAGE OF THE INVENTION According to this invention, a mobile body can be made movable in multiple directions using a simple structure.

FIG. 2 is a perspective view showing the configuration of a moving object according to an example of the present embodiment; Plan view of the moving body AA line sectional view of FIG. Side view of steering mechanism BB line sectional view of FIG. CC line sectional view of FIG. Side sectional view of the moving body

Hereinafter, embodiments of a mobile body and the like will be described with reference to the drawings. It should be noted that, since components denoted by the same reference numerals in the embodiments perform similar operations, repetitive description may be omitted.

In the following description, for convenience of explanation of the structure of the moving body, directions may be indicated with reference to the state where the moving body is in contact with the road surface, which is a horizontal plane. That is, the direction perpendicular to the road surface is sometimes referred to as the vertical direction. Also, the direction passing through the center of the moving body (not strictly speaking the center) in plan view may be referred to as the radial direction. A direction along an arc centered at the center of the moving body is sometimes referred to as a circumferential direction. Indicating each direction in this way is only for the convenience of explanation, and does not limit the orientation, posture, etc., when using the moving body according to the present invention.

(Embodiment)

In this embodiment, the moving body is provided so that three sets of arms to which wheels are attached protrude outward from the outer peripheral surface of the chassis. Each wheel is synchronously steered by the operation of a steering mechanism by one steering actuator. The arm is attached to the chassis so as to be rotatable up and down, and is a parallel link, but is not limited to this. The moving body 1 configured in this way will be described below.

FIG. 1 is a perspective view showing the configuration of a moving body 1 according to one example of the present embodiment. FIG. 2 is a plan view of the moving body 1. FIG. 3 is a cross-sectional view taken along the line AA of FIG. 2. FIG.

In the following description, illustration of the detailed configuration of the moving body 1 is omitted. For example, the structure of the chassis 2 other than the parts related to wheel suspension and steering may be appropriately set according to the use of the mobile body 1 and the like.

The moving body 1 includes a chassis 2, three arms 11, 21, and 31 (hereinafter each may be collectively referred to as an arm 10 without distinguishing them), and three wheels 51, 52, and 53 (hereinafter, , three drive actuators 61 , an arm rotating portion 71 , and three auxiliary wheels 81 . The moving body 1 also includes one steering actuator 64 , a steering mechanism 65 and a transmission mechanism 67 .

The mobile body 1 is normally placed on a substantially flat road surface and is movable on the road surface. The moving body 1 is used as, for example, a control unit (not shown) mounted on a chassis 2 (for example, it may be configured by a computer or an electric circuit), a sensor unit for detecting the surrounding situation, and a power supply for each unit. It has a battery etc. that can be used. The moving object 1 can move autonomously in multiple directions on the road surface based on the control of the control unit, which is performed based on, for example, a predetermined program, the detection results of the sensor unit, instructions received from the outside, and the like. It is configured. Here, being able to move in multiple directions means being able to move in various directions such as front, rear, left, right, and oblique directions while maintaining the orientation of the chassis 2 in a predetermined direction. Note that the mobile object 1 is not limited to one that can move autonomously. For example, it may be possible to move on the road surface by configuring various actuators to function based on a preset program, sequence, or the like. Moreover, it may be possible to move on the road surface by sending an instruction for operating each actuator from the outside.

The chassis 2 may be said to be the main body of the mobile body 1 or the frame of the mobile body 1 . In this embodiment, the chassis 2 is, so to speak, configured in a polygonal shape in plan view. The chassis 2 has a shape roughly triangular in plan view. More specifically, the side portions to which the three arms 10 are attached form an angle of roughly 60 degrees as will be described later. It should be noted that the chassis 2 may have a partially or wholly rounded shape.

The arm 10 is, for example, a component arranged linearly in a plan view. The arm 10 is arranged so as to extend substantially horizontally outward in the radial direction of the chassis 2 in a normal state (for example, when moving on a road surface that is a horizontal plane). In plan view, the arms 11, 21, and 31 are arranged circumferentially around the chassis 2 in this order in the clockwise direction. In this embodiment, each of the three arms 10 is configured to have approximately the same shape and dimensions. Each of the three arms 10 is arranged to form an angle of approximately 120 degrees with the other two arms 10 in plan view. That is, in plan view, the angle formed by the arms 11 and 21, the angle formed by the arms 21 and 31, and the angle formed by the arms 31 and 21 are all approximately 120 degrees. It is The three arms 10 are respectively arranged on the three side portions of the chassis 2 which is roughly triangular in plan view as described above. In this embodiment, arm 10 is supported on chassis 2 so as to protrude outward from the outer peripheral surface of chassis 2 . That is, the arm 10 is provided so that the direction in which it projects radially outward from the outer peripheral surface of the chassis 2, that is, the radial direction, is the longitudinal direction. In addition, the length of each arm 10, the mutual positional relationship, the direction in which the arm 10 protrudes outward from the chassis 2, and the like are not limited to this.

Here, in the present embodiment, the arm 10 includes a first link 111, a second link 112 disposed on the first link 111 and substantially parallel to the first link 111, and a support portion supporting the wheel 50. 115. The leading end of the first link 111 and the leading end of the second link 112 are attached to a support portion 115 to form a parallel link mechanism using two links 111 and 112 of equal length. It can be said that the wheels 50 are supported by the chassis 2 via the support portions 115 together with the drive actuators 61 . Also, it can be said that the wheels 50 are supported by the chassis 2 via the arms 10 . Wheels 50 are supported by support portions 115 so as to be rotatable about substantially vertical steering shafts 63 . It is also possible to interpret the first link 111 and the second link 112 themselves as arms.

Moreover, in the present embodiment, each arm 10 is supported with respect to the chassis 2 so as to be rotatable with respect to the chassis 2 . Here, that the arm 10 is rotatable with respect to the chassis 2 means that the two links 111 and 112 are each rotatable with respect to the chassis 2 around the arm rotation axis. That is, the first link 111 is rotatable about the arm rotation axis with respect to the chassis 2 by the arm rotating portion 71 . Also, the second link 112 is rotatable with respect to the chassis 2 around the arm rotation axis. Both the first link 111 and the second link 112 are configured to rotate with respect to the chassis 2 around their respective arm rotation axes by the driving force of the arm rotating portion 71 .

In the present embodiment, each arm rotation axis passes through the vicinity of the radially inner end of each arm 10 in plan view. Each arm rotation axis is a substantially horizontal axis. In each arm, the respective arm rotation axes of the two links 111, 112 are parallel to each other. The two links 111 and 112 are vertically rotatable with respect to the chassis 2 about the arm rotation axis from a substantially horizontal state in the longitudinal direction. That is, the arm 10 is rotatable with respect to the chassis 2 so that the portion apart from each arm rotation axis is vertically displaced. It may be said that the arm 10 is swingable or that the arm 10 is swingable.

Since the arm 10 is a parallel link, as the first link 111 and the second link 112 rotate with respect to the chassis 2, the support portion 115 is configured to be displaced to the upper limit while maintaining its posture. . Before and after the arm 10 rotates in this manner, the angle of the steering shaft 63 of the wheel 50 does not change. Therefore, even if the rotation angle of the arm 10 increases from the normal time, it is possible to prevent the load on the steering shaft 63, the steering actuator 64, and the like from increasing.

Here, in the present embodiment, the arm rotation axis of each of the three arms 10 is substantially perpendicular to the longitudinal direction of each arm 10 in plan view. Each arm rotation axis is arranged to form an angle of approximately 60 degrees with the arm rotation axes of the other two arms 10 in plan view. Further, in a plan view, straight lines that are perpendicular to the arm rotation axes of the three arms 10 and pass through a wheel 50, which will be described later, are configured to pass through one common point. It should be noted that the expression that each arm rotation axis passes through one common point can be roughly interpreted, and strictly speaking, it is an expression that allows a state in which the intersection points of the straight lines of the two arms 10 are displaced from each other. . The three arms 10 are radially arranged so as to protrude from the chassis 2 when viewed from the central portion of the chassis 2 .

It should be noted that the first link 111 and the second link 112 do not have a shape that is linear, such as being curved, or being a plate-like or A-shaped member when viewed from above. There may be. Further, the arm 10 does not constitute a parallel link as described above, but is, for example, a beam-shaped member, a curved member, or a member configured in a plate shape or an A shape in plan view. It may be composed roughly of one member such as In this case, a support portion 115 is provided at the tip of the arm 10 or the like, and the wheel 50 is supported by the support portion 117 so as to be rotatable about the steering shaft 63 .

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 the present embodiment, the wheel 50 is supported by a support portion 115 provided near the radially outer end (tip) of each of the three arms 10 .

More specifically, a wheel 51 is arranged at the tip of the arm 11, a wheel 52 is arranged at the tip of the arm 21, and a wheel 53 is arranged at the tip of the arm 31, respectively. Wheels 51 , 52 , 53 are arranged in this order in the clockwise direction for the entire mobile body 1 . The distance between each wheel 50 and the central portion of the chassis 2 is roughly equal. In other words, the wheels 50 supported by each of the three arms 10 are on a circle around one common point in plan view. In addition, the position of the wheel 50 is not restricted to this. It may be changed according to the length of the arms 10, the number of the arms 10, and the shape of the chassis 2. Moreover, in addition to one wheel 50, each arm 10 may be provided with wheels such as different auxiliary wheels.

The drive actuators 61 are provided so as to correspond to the wheels 50 of the three arms 10, respectively. The drive actuators 61 are configured to rotate the corresponding wheels 50 about their axles to move the moving body 1 . For example, the control unit controls the operation of each drive actuator 61 to move the moving body 1 . Further, for example, the moving body 1 may be movable by driving each drive actuator 61 in accordance with an instruction from the outside.

In this embodiment, the drive actuator 61 is, for example, various motors. The drive actuator 61 may have detection means such as an encoder capable of detecting the number of revolutions of the wheels 50, that is, the number of revolutions of the axle, or a motor such as a stepping motor capable of controlling the rotation angle. etc. Further, the drive actuator 61 may include a motor serving as a drive source and a transmission mechanism (for example, one using a gear or the like) that transmits the torque of the motor to the axle. In addition, a clutch may be provided so that the wheels 50 can freely rotate.

The arm rotating portion 71 is provided to correspond to each of the at least three arms 10 . Each arm rotating portion 71 is configured to rotate one arm 10 with respect to the chassis 2 around the arm rotating portion 71 . For example, the control section controls the operation of the arm rotating section 71 to rotate the corresponding arm 10 . Further, for example, the corresponding arm 10 may be rotatable by driving the arm rotating section 71 in accordance with an instruction from the outside.

Note that the arm rotating portion 71 is an actuator capable of controlling a rotation angle. The arm rotating part 71 is, for example, a servo motor or a stepping motor, but is not limited to this. For example, the arm rotating section 71 may be an actuator such as a motor that includes an encoder or the like and is configured to be able to control the rotation angle. Further, the arm rotating section 71 may be one that rotates the arm 10 using a hydraulic actuator. Further, the arm rotation part 71 is a direct-acting type that is arranged between a support shaft that rotatably supports the arm 10 with respect to the chassis 2 and a part of the arm 10 and the chassis 2 to change the distance between the two. and an actuator.

The auxiliary wheels 81 are arranged so as to be positioned between the chassis 2 and the road surface. In this embodiment, the auxiliary wheels 81 are arranged on the surface of the chassis 2 facing the road surface. The auxiliary wheel 81 can be configured to be rotatable around a vertical axis in accordance with the moving direction of the moving body 1, for example, like a so-called swivel caster, but is not limited to this. In this embodiment, three auxiliary wheels 81 are provided. The three auxiliary wheels 81 are arranged on straight lines that are perpendicular to each arm rotation axis and pass through the central portion of the chassis 2 . Thus, the mobile body 1 is configured such that the chassis 2 is stably supported by the one or more auxiliary wheels 81 even when the one or more wheels 50 are separated from the road surface or the like. The number and positions of the auxiliary wheels 81 are not limited to this, and may be one, two, or four or more.

In this embodiment, the three wheels 51 , 52 , 53 are configured to rotate around their respective steering shafts 63 in synchronization with the operation of one steering actuator 64 . A steering actuator 64 is arranged on the chassis 2 . The steering actuator 64 is an actuator for steering each wheel 50 . For example, the controller controls the operation of the steering actuator 64 so that each wheel 50 rotates around the steering shaft 63 in synchronization. Further, for example, steering may be performed by driving the steering actuator 64 in accordance with an instruction from the outside. A specific configuration of a steering system that realizes steering of three wheels 50 using one steering actuator 64 will be described later.

Note that in the present embodiment, the steering actuator 64 is an actuator capable of controlling the steering angle of each wheel 50 . The steering actuator 64 is, for example, a servo motor or a stepping motor, but is not limited to this. For example, the steering actuator 64 may be an actuator such as a motor that is provided with an encoder or the like and configured to be able to control its own rotation angle. Also, the steering actuator 64 may be an actuator such as a motor configured to be able to control the output shaft according to the steering angle detected using an encoder provided on at least one wheel 50 . Also, the steering actuator 64 may be one that uses a hydraulic actuator to rotate its output shaft. Moreover, the steering actuator 64 may be configured to include a direct-acting actuator.

As described above, in the moving body 1 , the wheel 50 is attached to the tip portion, and the arm 10 that is vertically displaceable with respect to the chassis 2 is arranged so as to protrude radially from the chassis 2 . Each wheel 50 is rotatable by a driving actuator 61 and synchronously steerable by one steering actuator 64 . Therefore, the moving body 1 has the following capabilities. That is, the moving body 1 can move in multiple directions. In addition, when moving in multiple directions, the moving body can climb over steps in those directions. In addition, the moving body 1 can adjust the attitude of the chassis 2 by rotating the three arms 10 with respect to the chassis 2 while the wheels 50 are in contact with the ground surface. Therefore, for example, it is possible to easily meet the needs for stabilizing the posture for transportation.

When the moving body 1 climbs over a step in the movement direction, for example, the arm 10 may be rotated with respect to the chassis 2 as follows.

That is, in the present embodiment, the moving body 1 rotates the arm 10 with respect to the chassis 2 by the arm rotating portion 71 so that the wheels 50 supported by the arm 10 are vertically moved with respect to the chassis 2 . can be displaced. When at least one arm 10 rotates upward, the wheel 50 supported by the arm 10 moves upward (floats) from the road surface. Also, downward rotation of one or more arms 10 lifts the chassis 2 upwards from the road surface.

For example, in the present embodiment, moving body 1 moves so that wheel 50, which is lifted by rotating arm 10 upward, moves closer to a step that rises in the traveling direction, and puts wheel 50 on the step. In addition, the moving body 1 moves over a level difference that becomes lower in the traveling direction by rotating the arm 10 downward, so that the floating wheel 50 touches the bottom of the level. In accordance with this, the moving body 1 raises or lowers the chassis 2 by rotating each arm 10 up and down. By appropriately changing the rotating arm 10 and its rotating direction according to the movement direction of the moving body 1 and the position of the step, a series of operations to overcome the step are performed. As a result, the moving body 1 can move in multiple directions over steps.

Next, the configuration of a steering system that realizes steering of three wheels 50 according to this embodiment will be described. As described above, in the mobile body 1 , all the wheels 50 are rotatable by the drive actuator 61 and synchronously steerable by one steering actuator 64 . As a result, the moving body 1 can move in multiple directions according to the driving state of each wheel 50 (rotating around the axle or around the steering shaft 63). That is, in the present embodiment, one steering actuator 64 and the driving actuators 61 of the wheels 50 constitute a moving mechanism for moving the moving body 1 .

In this embodiment, the operation of one steering actuator 64 is reflected in the steering of each wheel 50 using the steering mechanism 65 and transmission mechanism 67 . The steering mechanism 65 is arranged, for example, at the central portion of the chassis 2 , that is, at the turning center of the moving body 1 . A transmission mechanism 67 is provided for each wheel 50 . Each transmission mechanism 67 is configured to connect the steering mechanism 65 and each wheel 50 .

In this embodiment, the steering mechanism 65 is configured to rotate a total of three output members 166 corresponding to each wheel 50 in the same direction according to the operation of one steering actuator 64 . Each transmission mechanism 67 is configured to transmit the torque of the output member 166 as torque that rotates the corresponding wheel 50 around the steering shaft 63 .

4 is a side view of the steering mechanism 65. FIG. 5 is a cross-sectional view taken along the line BB of FIG. 4. FIG. FIG. 6 is a sectional view taken along line CC of FIG.

In this embodiment, the steering mechanism 65 is a gearbox containing a plurality of bevel gears. That is, the steering mechanism 65 has an input member 161 , an output member 166 , a first bevel gear 162 and a second bevel gear 163 . Each component is attached to casing 160 . The steering actuator 64 is attached to the top of the steering mechanism 65, for example.

One input member 161 is provided. The input member 161 is a rotating shaft arranged in parallel in the vertical direction in the central portion of the chassis 2 . The input member 161 may be called an input shaft. The input member 161 is rotatably held with respect to the casing 160 using bearings or the like. An output shaft of the steering actuator 64 is coupled to the input member 161 . The input member 161 may be the output shaft of the steering actuator 64 . That is, the input member 161 is configured to move according to the operation of the steering actuator 64 . It can be said that the input member 161 rotates according to the operation of the steering actuator 64 .

Three output members 166 are provided to correspond to each wheel 50 , that is, to correspond to each arm 10 . This number may be greater than the number of wheels 50 . The output member 166 is a rotating shaft arranged to pass through the side surface of the casing 160 in a substantially horizontal posture. The output member 166 may be called an output shaft. The output member 166 is rotatably held with respect to the casing 160 using bearings or the like. A transmission mechanism 67 is coupled to the output member 166 . A coupling 67b or the like is used for the connecting portion between the output member 166 and the transmission mechanism 67, but it is not limited to this. For example, they may be directly connected, or the boundary between the output member 166 and the transmission mechanism 67 may not be distinguished.

One first bevel gear 162 is provided. The first bevel gear 162 is fixed to the input member 161 inside the casing 160 . The first bevel gear 162 rotates together with the input member 161 . That is, the first bevel gear 162 interlocks with the input shaft.

Three second bevel gears 163 are provided so as to correspond to each output member 166 , that is, to correspond to each wheel 50 . This number may be greater than the number of wheels 50 . Each second bevel gear 163 is fixed to a corresponding output member 166 inside casing 160 . That is, the second bevel gear 163 is arranged to rotate together with each output shaft. Each second bevel gear 163 is provided so as to mesh with the first bevel gear 162 .

Since the steering mechanism 65 is configured in this way, the input member 161 rotates according to the operation of the steering actuator 64 and each output member 166 rotates according to the rotation of the input member 161 . That is, in this embodiment, the output member 166 is configured to interlock with the operation of the input member 161 .

FIG. 7 is a side sectional view of the moving body 1. As shown in FIG.

The cross-section shown in FIG. 7 is taken through the steering mechanism 65, the arm 11 corresponding to the wheel 51, and the transmission mechanism 67. FIG. 7 shows a normal state in which the grounding portion of the wheel 51 is at the same height as or slightly below the grounding portion of the auxiliary wheel 81. In FIG. 7 shows a state in which the arm 11 is rotated upward from the normal state and the wheel 51 is displaced upward.

The transmission mechanism 67 forms a torque transmission path from the steering mechanism 65 to the wheels 51 . In this embodiment, the transmission mechanism 67 has an external transmission portion 68 located outside the chassis 2 and a coupling 67b arranged in the middle of the transmission path. Further, in this embodiment, a steering portion 69 is provided above the steering shaft 63 of the wheel 50 . The steering portion 69 is housed inside the support portion 115, for example. The steering section 69 may be interpreted as being included in the transmission mechanism 67 or may be interpreted as not being included.

Each transmission mechanism 67 is configured to rotate according to rotation of the corresponding output member 166 . The transmission mechanism 67 has a shaft that transmits torque from the inside of the chassis 2 to an external transmission portion 68 outside. The external transmission section 68 has, for example, two constant velocity joints provided near the chassis 2 and near the wheels 50 respectively, and is connected to the steering section 69 . In the present embodiment, the external transmission portion 68 is arranged substantially parallel to the links 111 and 112, but the configuration is not limited to this. The external transmission portion 68 transmits torque transmitted from the inside of the chassis 2 to the steering portion 69 . The steering portion 69 has, for example, a structure in which a bevel gear that rotates together with the external transmission portion 68 and a bevel gear that rotates together with the steering shaft 63 mesh with each other. As the external transmission portion 68 rotates, the steering shaft 63 rotates accordingly.

Thus, each transmission mechanism 67 rotates the corresponding wheel 50 around the steering shaft 63 according to the operation of the corresponding output member 166 . Thus, in the moving body 1 , each wheel 50 is synchronously steered according to the operation of one steering actuator 64 .

Note that the number of teeth of the first gear 162 and the number of teeth of the second gear 163 are appropriately set according to the configuration of the steering actuator 64, the configuration of the transmission mechanism 67, the requirements related to the steering of the wheels 50, and the like. The number of teeth of each second gear 163 and the number of teeth of each bevel gear of each steering portion 68 are configured to be the same. Thereby, each wheel 50 can be rotated synchronously.

Here, the transmission mechanism 67 is provided with an external transmission portion 68 configured using a constant velocity joint. Therefore, as shown in the lower part of FIG. 7, even when the arm 1 is displaced vertically from the normal state, torque is smoothly transmitted from the steering mechanism 65 to the steering section 69, so that each wheel 50 can be operated. becomes. Therefore, it is possible to move the moving body 1 in multiple directions by steering the wheels 50 while rotating the arm 1 to climb over a step.

As described above, according to the present embodiment, the moving body 1 can synchronously steer a plurality of wheels 50 with one steering actuator 64 . The configuration of the moving body 1 can be simplified, and the configuration and control details of the control unit that controls each actuator and the like can also be simplified. Therefore, the moving body 1 can be made movable in multiple directions using a simple configuration.

Here, many of conventional mobile bodies designed for rough terrain have a mechanism having a lifting function on the wheels. When using such a mechanism, it is necessary to steer the wheels independently for each axis using an actuator such as a motor. However, such a complicated configuration leads to an increase in cost.

On the other hand, in the present embodiment, as described above, the moving body 1 is configured to move over a step by rotating the arm 1 while steering the wheels 50 to move in multiple directions. there is Therefore, the mobile body 1, which can move in many directions and can climb over steps, can be configured simply.

The steering mechanism 65 and the transmission mechanism 67 are configured to be able to steer the wheels 50 by rotating the transmission mechanism 67 using bevel gears. Therefore, a large steerable range of each wheel 50 can be ensured, and the wheels 50 can be smoothly moved in multiple directions while being rotated about the axle.

The steering actuator 64 can be arranged inside the chassis 2 . Therefore, even in the case of using the steering actuator 64, which has relatively poor water resistance, the water resistance of the moving body 1 can be kept high.

(others)

The present invention is not limited to the above embodiments, and various modifications are possible and are also included within the scope of the present invention.

The transmission mechanism may use, for example, a flexible member such as a wire capable of transmitting torque. In this case also, each wheel can be steered while the arm is rotatable up and down.

Further, each transmission mechanism may be provided with a clutch for turning on/off transmission of torque. In this case, by driving the steering actuator while changing the connection state of the clutch corresponding to each wheel, it is possible to steer the steering angles of the wheels to different angles. For example, by setting each wheel at a steering angle substantially perpendicular to the radial direction when viewed from the central portion of the chassis, the moving body 1 can be turned on the spot.

Further, for example, the steering mechanism and the transmission mechanism may be configured using links or the like. For example, the steering section has a lever that protrudes radially from the steering shaft, and the transmission mechanism moves the tip of the lever relative to the chassis according to the displacement of the output member. It may be configured such that steering of the wheels is performed by operating to move closer and closer. Such a configuration includes, for example, a steering actuator that is a servomotor, a so-called servo horn (an example of an output member) interlocked with its output shaft (an example of an input member), and a link member that connects the servo horn and the lever. It can be configured by a transmission mechanism or the like. In this case, a wire or the like that pulls the lever toward the chassis may be used as the transmission mechanism, and the steering portion may be configured using a spring or the like that biases the steering shaft so as to rotate the steering shaft in the direction in which the lever moves away from the chassis. .

For example, training wheels may not necessarily be provided. For example, in the embodiments described above, the surface of the chassis facing the road surface is provided with an abutment configured to contact the road surface instead of the wheels when one or more arms rotate upward. may In this case, the contact portion may have, for example, a spherical member rotatably held by the chassis, or may be fixed to the chassis and provided so as to be in sliding contact with the road surface. may be It is preferable that the contact portion is configured to have a small coefficient of friction with the road surface.

The number of arms is not limited to three, and four or more arms may be provided. In the above-described embodiment, the three arms are arranged to form a Y shape in plan view, but this is not the only option. For example, four arms may be arranged around the chassis to form an X shape in plan view. By increasing the number of arms, it is possible to improve the stability during running and the stability during overcoming obstacles. In this case, by setting the number of output shafts of the steering mechanism and the number of transmission mechanisms to four, the wheels of each arm can be steered synchronously.

An embodiment may be configured by appropriately combining each configuration according to the above-described embodiments and the like. For example, it is not limited to the configurations of the above-described embodiments and the like, and each component of the above-described embodiments and the like may be appropriately replaced or combined with components of other embodiments and the like. Further, some components and functions may be omitted from the above-described embodiments and the like.

It should be noted that the structure of the moving body as described above can be widely used, for example, as an outdoor/indoor carrier robot or a foot support device for a mobile work robot with a robot arm.

INDUSTRIAL APPLICABILITY 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 or the like.

Reference Signs List 1 moving body 2 chassis 10, 11, 21, 31 arm 50, 51, 52, 53 wheel 60 movement mechanism 61 drive actuator 63 steering shaft 64 steering actuator 65 steering mechanism 67 transmission mechanism 71 arm rotation part 111 first link 112 second link 115 support part

Claims (5)

a chassis;
They are arranged circumferentially around the chassis in a plan view, are supported by the chassis via a support portion, and are rotatable about the steering shaft with respect to the support portion. there are at least three wheels and
at least three drive actuators associated with each of the wheels to rotate the corresponding wheel about its axle;
a steering actuator for steering the wheels;
a steering mechanism having an input member that moves in response to operation of the steering actuator and an output member configured to interlock with the operation of the input member;
at least three transmission mechanisms provided corresponding to each of the wheels and rotating the corresponding wheels about the steering shaft according to the operation of the corresponding output members;
A moving object, wherein the wheels are synchronously steered according to the operation of the steering actuator. They are arranged circumferentially around the chassis in a plan view, are rotatable up and down, and are supported with respect to the chassis so as to protrude outward from the outer peripheral surface of the chassis. , at least three arms, and
an arm rotation unit provided to correspond to each of the arms and capable of rotating one of the arms with respect to the chassis;
The support portion is provided on each of the arms,
2. The moving body according to claim 1, wherein said wheels are supported by said arms at positions spaced outward from the outer peripheral surface of said chassis. each of the arms includes a first link and a second link substantially parallel to the first link;
3. The moving body according to claim 1, wherein said support section is connected to said first link and said second link so as to form a parallel link. The steering mechanism has an input shaft that rotates according to the operation of the steering actuator, and an output shaft that rotates according to the rotation of the input shaft, and
4. Each of the transmission mechanisms rotates according to the corresponding output shaft, and transmits torque of each of the output shafts as torque for rotating each of the at least three wheels about the steering shaft. The mobile body according to any one of The moving body according to any one of claims 1 to 4, wherein said transmission mechanism has a constant velocity joint.

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