JP2002210682A - Leg structure of leg-type moving robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the driving force for driving a lower leg part by reducing the moment of inertia around a revolute joint of knee, and to minimize the influence of the noise of a motor on a six-component sensor mounted on a foot part. SOLUTION: A lower leg part 24 is connected to a lower end of an upper leg part 23 through the revolute joint of knee 27, the foot part 25 having the six-component sensor 60 is connected to a lower end of the lower leg part 24 through a revolute joint of ankle, and the revolute joint of ankle 28 supports the leg part to the lower leg part 24 in a state that it can be pitched around a lateral axis Ly and rolled in the longitudinal axis Lx. A pitching motor 34 for pitching the foot part 25 around the lateral axis Ly I is supported on the lower leg part 24 at an upper part with respect to the revolute joint of ankle 28, and a rolling motor 35 for rolling the foot part 25 around the longitudinal axis Lx is supported on the lower leg part 24 at the upper part with respect to the revolute joint of ankle 28.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a leg structure of a legged mobile robot, and more particularly to connecting a lower leg to a lower end of an upper leg via a knee joint, and connecting a foot to a lower end of the lower leg and an ankle joint. The present invention relates to a leg structure of a leg-type mobile robot that supports the legs so that the legs can be freely pitched and rolled with respect to the lower legs.

[0002]

2. Description of the Related Art The leg structure of such a legged mobile robot is known from Japanese Patent Application Laid-Open No. 3-184772. This is a pitching motor provided at a position near the upper end of the lower leg portion, which causes the lower leg portion to pitch the foot portion around the pitching shaft portion via belt transmission means, and performs rolling perpendicular to the pitching shaft portion. The foot is rolled with respect to the lower leg by a rolling motor provided on the shaft.

[0003]

When the lower leg is driven relative to the upper leg, if the moment of inertia below the knee joint connecting the upper leg and the lower leg is reduced, then
The load on the drive source that drives the lower leg can be reduced. In order to reduce the moment of inertia, it is desirable that the position of a heavy object attached to the lower leg is made as close as possible to the knee joint. Although it is located near the joint, another heavy load, the rolling motor, is located at the lower part of the lower leg, that is, far from the knee joint, so that the moment of inertia below the knee joint is sufficient. There was a problem that it could not be reduced.

A six-component force sensor for controlling the robot to walk on two legs is attached to the foot.
If the rolling motor is provided at the lower part of the lower leg near the foot, there is a problem that special measures for reducing the influence of the noise are required.

In addition, since the rolling motor is provided in the vicinity of the ankle joint, the position of the ankle joint from the floor becomes high, and the control amount of the compliance control of the ankle joint becomes large. There was a problem that it was difficult to quickly respond to the inclination.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and aims to reduce the moment of inertia around the knee joint to reduce the driving force for driving the lower leg, and to reduce the noise of the motor on the sensor provided on the foot. It is another object of the present invention to minimize the influence on the floor, and to lower the position of the ankle joint from the floor so that it can quickly cope with unexpected irregularities or inclination of the floor.

[0007]

According to the first aspect of the present invention, a lower leg is connected to a lower end of an upper leg via a knee joint. A leg of a legged mobile robot that connects a foot to a lower end through an ankle joint, and the ankle joint supports the foot with respect to the lower leg so as to be able to pitch freely around the left and right axes and to freely roll around the front and rear axis. In the structure, the pitching motor for pitching the foot around the left and right axis is supported on the lower leg above the ankle joint, and the rolling motor for rolling the foot about the front and rear axis is above the ankle joint. A leg structure of a legged mobile robot characterized by being supported on a lower leg is proposed.

According to the above construction, the pitching motor for pitching the foot around the left-right axis and the rolling motor for rolling the foot about the front-rear axis are supported on the lower leg above the ankle joint. The positions of the pitching motor and the rolling motor, which are heavy objects, approach the knee joint, the moment of inertia of the lower leg around the knee joint decreases, and the load on the drive source for driving the knee joint can be reduced.

According to the invention described in claim 2,
In addition to the configuration of claim 1, a pitching shaft portion rotatably supported on the lower leg portion around the left-right axis, and pitching for transmitting rotation of an output shaft of a pitching motor disposed in the left-right axis direction to the pitching shaft portion. A leg structure of a legged mobile robot, comprising: a belt transmission means for use; and a rolling mechanism for rotatably supporting the foot on the pitching shaft.

According to the above construction, the foot is rotatably supported via the rolling mechanism on the pitching shaft which is rotatably supported on the lower leg portion around the left-right axis, and the rotation of the output shaft of the pitching motor is controlled by the pitching shaft. Since the pitching shaft is driven through the pitching belt transmitting means for transmitting to the part, the rolling mechanism and the foot are pitched integrally by rotating the pitching shaft, and the rolling mechanism is actuated to the pitching shaft. In contrast, the foot can be rolled, and the pitching and rolling of the foot can be prevented from interfering with each other.

According to the third aspect of the present invention,
The lower leg is connected to the lower end of the upper leg via the knee joint, and the foot is connected to the lower end of the lower leg via the ankle joint. The ankle joint pitches the foot relative to the lower leg around the left and right axis. A leg structure of a legged mobile robot that freely supports and rolls freely around the front-rear axis, and is fixed so as to be orthogonal to each other, and each of which rotates around a left-right axis and a front-rear axis. A rotating member rotatably supported on one outer periphery of the pitching shaft portion and the rolling shaft portion and rotating integrally with the foot portion; and a first member for rotating the other of the pitching shaft portion and the rolling shaft portion. A drive source, a drive bevel gear coaxially arranged inside the other of the pitching shaft portion and the rolling shaft portion, and a drive bevel gear coaxially arranged inside one of the pitching shaft portion and the rolling shaft portion. A driven bevel gear coupled to the rotating member while meshing with the drive bevel gear is, the leg structure of the legged mobile robot, characterized in that the driving bevel gear and a second driving source for driving rotation is proposed.

According to the above construction, the rotating member integrally provided with the foot is rotatably supported on one of the outer circumferences of the pitching shaft and the rolling shaft fixed to be orthogonal to each other. A driving bevel gear coaxially arranged inside the other of the rolling shaft portion and a driven bevel gear coaxially arranged inside one of the pitching shaft portion and the rolling shaft portion and connected to the rotating member; Since the other of the pitching shaft portion and the rolling shaft portion is rotated by the drive source, and the drive bevel gear is rotated by the second drive source, pitching and rolling of the feet can be performed independently without affecting each other. it can. Moreover, since the positions of the rolling shaft and the pitching shaft can be lowered, compliance control of the ankle joint can be realized with a smaller control amount,
It is possible to promptly respond to unexpected irregularities or inclinations of the floor surface, thereby enabling stable walking.

Further, according to the invention described in claim 4,
The lower leg is connected to the lower end of the upper leg via the knee joint, and the foot is connected to the lower end of the lower leg via the ankle joint. The ankle joint pitches the foot relative to the lower leg around the left and right axis. It is a leg structure of a legged mobile robot that freely supports and supports rolling freely around the front-rear axis, and a rolling mechanism that supports the foot freely on the pitching shaft so that it is orthogonal to the pitching shaft. A fixed rolling shaft, a rolling member fixed integrally to the foot and rotatably supported on the outer periphery of the rolling shaft, a driving bevel gear coaxially arranged in the pitching shaft, and arranged in the left-right axial direction. A rolling belt transmitting means for transmitting the rotation of the output shaft of the rolling motor to the driving bevel gear, and being coaxially arranged in the rolling shaft and meshing with the driving bevel gear. Leg structure of the legged mobile robot is characterized in that a follower is coupled to the rolling member bevel gear is proposed together.

According to the above construction, the rolling member integrally provided with the foot is rotatably supported on the outer periphery of the rolling shaft fixed to be perpendicular to the pitching shaft, and the rotation of the output shaft of the rolling motor is controlled. Is transmitted to the rolling member via a belt transmission means for rolling, a drive bevel gear coaxially arranged in the pitching shaft, and a driven bevel gear coaxially arranged in the rolling shaft.
The feet can be independently rolled without affecting the pitching of the feet, and the feet can be freely pitched in a rolled state.
In addition, because the position of the rolling shaft and pitching shaft can be lowered, compliance control of the ankle joint can be achieved with a smaller control amount, and it is stable in response to unexpected irregularities or inclination of the floor surface Walking can be made possible.

According to the invention described in claim 5,
In addition to the constitution of claim 4, a leg-type movement characterized in that a pitching speed reducer is arranged between the pitching belt transmission means and the pitching shaft, and a rolling speed reducer is arranged between the driven bevel gear and the rolling member. A robot leg structure is proposed.

According to the above construction, since the pitching speed reducer is arranged between the pitching belt transmitting means and the pitching shaft, the load on the pitching motor can be reduced, and the rolling between the driven bevel gear and the rolling member can be reduced. The load on the rolling motor can be reduced because the speed reducer is arranged.

According to the invention described in claim 6,
In addition to the configuration of claim 4 or 5, the outside of the rolling member is covered with a partial spherical cover, and a predetermined gap is formed between the lower end of the lower leg link constituting the skeleton of the lower leg and the partial spherical cover. A leg structure of a legged mobile robot characterized by the following is proposed.

According to the above configuration, since the predetermined gap is formed between the partial spherical cover that covers the outside of the rolling member and the lower end of the lower leg link, even if the feet are pitched and rolled, the partial spherical cover and It is possible to prevent a large gap from being generated between the lower leg links and effectively prevent foreign matter from being caught.

According to the invention described in claim 7,
In addition to the configuration of claim 6, a leg structure of a legged mobile robot is proposed, wherein the partial spherical cover has a center on the pitching shaft portion or the rolling shaft portion.

According to the above configuration, since the center of the partial spherical cover is located on the pitching shaft portion or the rolling shaft portion, the partial spherical cover is formed between the partial spherical cover and the lower leg link when the foot is pitched or rolled. The gap can be kept constant, the partial spherical cover can be prevented from interfering with the lower leg link, and the movable range of the ankle joint can be expanded, and the foreign object can be more effectively prevented from being caught.

According to the invention described in claim 8,
In addition to the configuration of any one of claims 1 to 7, a leg structure of a legged mobile robot is provided, wherein a sensor for detecting a load applied to the foot is provided on the foot. .

According to the above configuration, since the positions of the pitching motor and the rolling motor are far from the foot, the sensor provided on the foot is hardly affected by the noise of the motor, and the detection accuracy of the sensor is improved. .

The pitching motor 34 and the rolling motor 35 of the embodiment constitute a first drive source and a second drive source of the present invention, respectively, and the rolling member 46 of the embodiment constitutes a rotating member of the present invention. The inner partial spherical cover 62 and the outer partial spherical cover 63 of the embodiment constitute the partial spherical cover of the present invention, and the six-component force sensor 60 of the embodiment constitutes the sensor of the present invention.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on embodiments of the present invention shown in the accompanying drawings.

FIGS. 1 to 7 show an embodiment of the present invention. FIG. 1 is a front view of a legged mobile robot, FIG. 2 is a right side view of the legged mobile robot, and FIG. 3 is an enlarged sectional view taken along line -3 (a sectional view taken along line 3-3 in FIG. 4). FIG. 4 is a sectional view taken along line 4-4 in FIG. 3, FIG. 5 is a perspective view of the lower leg and the foot, and FIG. FIG. 7 is an explanatory diagram of the operation of rolling the foot.

As shown in FIGS. 1 and 2, a legged mobile robot R capable of independent bipedal walking has a torso 11, a head 12,
Left arm 13L, right arm 13R, left leg 14L and right leg 14R
And an electrical component box 15 containing electrical components is carried on the back of the body 11. Each of the left arm 13L and the right arm 13R includes an upper arm 16, a lower arm 17, and a hand 1
And the torso 11 and the upper arm 16 are connected to the shoulder joint 1
9, the upper arm 16 and the lower arm 17 are connected to the elbow joint 20.
The lower arm 17 and the hand 18 are connected by a wrist joint 21, and an upper arm for twisting the lower half with respect to the upper half of the upper arm 16 is provided in the middle of the upper arm 16 in the longitudinal direction. Joint 22
Is provided. Each of the left leg 14L and the right leg 14R includes an upper leg portion 23, a lower leg portion 24, and a foot portion 25, and the body 11 and the upper leg portion 23 are connected by a hip joint 26,
The upper leg 23 and the lower leg 24 are connected by a knee joint 27, and the lower leg 24 and the foot 25 are connected by an ankle joint 28. Further, the body 11 and the head 12 are connected by a neck joint 29. still,
Only the position of each joint is indicated by a dashed circle.

Next, the structure of the right leg 14R of the robot R will be described with reference to FIGS. The left leg 14L is the right leg 1
Since the same structure is mirror-symmetrical to 4R, the overlapping description is omitted.

The upper leg 23 and the lower leg 24 are connected by a knee joint 27 having an axis L, and are driven by a drive source (not shown) through a belt transmission means 31 and a speed reducer 32. The lower leg portion 24 is a lower leg link 33 constituting its skeleton.
An output shaft 34a is provided at the upper end of the lower leg link 33.
Pitching motor 34 in which is disposed in the left-right axis Ly direction.
And a rolling motor 35 having an output shaft 35a arranged in the left-right axis Ly direction is supported at an intermediate portion of the lower leg link 33.

On the left-right axis Ly, the pitching shaft 36 is rotatably supported at the lower end of the lower leg link 33 via a pair of cross roller bearings 38, 38 (FIG. 3).
reference). A drive pulley 39 provided on an output shaft 34 a of the pitching motor 34 and a driven pulley 40 arranged on the left-right axis Ly are connected by an endless belt 41. The drive pulley 39, the driven pulley 40, and the endless belt 41 constitute a belt transmission means 42 for pitching. The driven pulley 40 and the pitching shaft 36 are connected by a pitching speed reducer 43 composed of a known harmonic speed reducer (trade name).
The harmonic reducer reduces the rotation of the input member and outputs the reduced rotation to an output member disposed coaxially, and it can be replaced with a planetary gear reducer.

A rolling shaft 44 extending in a direction perpendicular to the pitching shaft 36 (front-rear axis Lx) is formed integrally with the pitching shaft 36 (see FIG. 4). A cylindrical rolling member 46 is supported on the outer periphery of the rolling shaft 44 via a pair of cross roller bearings 47, and the foot 25 is fixed to the rolling member 46.

A driven pulley 52 fixed to the shaft end of a drive bevel gear shaft 51 rotatably supported inside a pitching shaft portion 36, and an output shaft 35 of a rolling motor 35
The drive pulley 53 fixed to a is connected by an endless belt 54, and the drive pulley 53, the driven pulley 52, and the endless belt 54 constitute a belt transmission means 55 for rolling. A driven bevel gear 57 provided at the shaft end of a driven bevel gear shaft 56 rotatably supported inside a rolling shaft portion 44 integrally formed with the pitching shaft portion 36 is provided at the shaft end of the drive bevel gear shaft 51. It meshes with the drive bevel gear 58. Then, the shaft end of the driven bevel gear shaft 56 and the rolling member 46 are connected by a rolling reduction gear 59 composed of a harmonic reduction gear. On the upper surface of the central portion of the foot 25, a six-component force (a load in three orthogonal directions and a moment about the three axes) acting on the foot 25 is detected to cause the robot R to walk on two feet. A component force sensor 60 is provided, and an amplifier 64 of the 6-component force sensor 60 is provided on the rear upper surface of the foot 25.

The rolling mechanism 61 for rolling the foot 25 with respect to the pitching shaft 36 includes the rolling shaft 44, the rolling member 46, the driving bevel gear shaft 51, the driving bevel gear 58, and the driven bevel gear shaft 56.
, A driven bevel gear 57, and a rolling belt transmission means 55.

As will be apparent with reference to FIGS.
An ankle joint 28 that supports the foot 25 so as to be able to pitch and roll with respect to the lower leg 24 includes an inner part spherical cover 62 that forms a part of a concentric spherical surface centered on the intersection of the front-rear axis Lx and the left-right axis Ly, and an outer part. A partial spherical cover 63 is provided. The inner part spherical cover 62 is fixed to the rolling member 46, while the outer part spherical cover 63 is fixed to the pitching shaft part 36. Therefore, when the foot 25 pitches around the left-right axis Ly, the inner part spherical cover 62 and the outer part spherical cover 63 pitch together, and when the foot 25 rolls around the front-rear axis Lx, Only the inner partial spherical cover 62 rolls relative to the partial spherical cover 63. Even if the outer part spherical cover 63 and the inner part spherical cover 62 rotate relative to each other, the inner part spherical cover 6
2 has a shape that is substantially rotationally symmetric about the front-rear axis Lx, so that a step or gap is not generated in the shape of the partial spherical surface formed by the outer spherical cover 63 and the inner spherical cover 62. Absent. A concave spherical surface 33a is formed at the lower end of the lower leg link 33, and a minute and uniform gap α is formed between the concave spherical surface 33a and the outer peripheral surfaces of the outer spherical cover 63 and the inner spherical cover 62. .

Next, the operation of the embodiment of the present invention having the above configuration will be described.

When the pitching motor 34 is driven to pitch the foot 25 connected to the lower end of the lower leg 24 of the robot R via the ankle joint 28 around the left-right axis Ly, the rotation of the output shaft 34a is used for pitching. The transmission is transmitted to the pitching speed reducer 43 via the drive pulley 39, the endless belt 41, and the driven pulley 40 of the belt transmission means 42. The pitching speed reducer 43 reduces the input rotation and outputs the rotation to the pitching shaft portion 36. Pitching shaft 36
However, together with the rolling shaft portion 44 integral therewith, the left and right axis L
When rotated around y, the foot 25 supported by the rolling shaft 44 via the rolling member 46 pitches around the left-right axis Ly. Thus, the pitching shaft 3
6 is rotated, the driving bevel gear shaft 51 of the rolling mechanism 61 is coaxially disposed inside the pitching shaft portion 36 and is relatively rotatable.
By keeping the wheel 5 free to spin, the foot 25 is prevented from rolling unnecessarily.

When the motor 35 for rolling is driven to roll the foot 25 around the longitudinal axis Lx, the rotation of the output shaft 35a is transmitted to the belt transmission means 55 for rolling.
Pulley 53, endless belt 54 and driven pulley 5
The rotation of the drive bevel gear shaft 51 is transmitted through the drive bevel gear 58, the driven bevel gear 57, and the driven bevel gear shaft 56, and the rotation of the drive bevel gear shaft 51 is converted to a 90 ° direction. The power is transmitted to the rolling member 46 and the foot 25 integrated with the rolling member 46 is rolled. As described above, the rolling mechanism 61 is supported by the pitching shaft 36 and the foot 2
5, and the rolling mechanism 61 is operated alone to move the foot 25 against the pitching shaft 36.
, The pitching and the rolling do not interfere with each other or intersect with each other, and the control of the pitching and the rolling of the foot 25 is simplified.

The pitching motor 34 and the rolling motor 35 are connected to the lower leg 2 above the ankle joint 28.
4, the pitching motor 3 which is heavy
4 and the position of the rolling motor 35 approach the knee joint 27. As a result, the moment of inertia of the lower leg 24 around the knee joint 27 can be reduced, and the load on the drive source that drives the knee joint 27 can be reduced. Moreover, since the positions of the pitching motor 34 and the rolling motor 35 are far from the 6-component force sensor 60 provided on the foot 25, the 6-component force sensor 60 is affected by the noise of the pitching motor 34 and the rolling motor 35. It becomes difficult and the detection accuracy is improved.

Further, the pitching shaft portion 36 is formed by the above arrangement of the pitching motor 34 and the rolling motor 35.
In addition, the position of the rolling shaft 44 is lowered, and compliance control of the ankle joint 28 can be realized with a smaller control amount. Thereby, it is possible to promptly respond to unexpected irregularities or inclinations of the floor surface and to perform stable walking.

Further, when the feet 25 are pitched, the inner partial spherical cover 62 and the outer partial spherical cover 63 around the intersection of the left-right axis Ly and the front-rear axis Lx rotate together. Lower leg link 3
The gap α between the bottom surface 3 and the concave spherical surface 33a is kept constant, so that foreign matter can be prevented from being caught. When the foot 25 is rolled, the inner part spherical cover 62 rotates relatively to the outer part spherical cover 63,
Since the gap α does not change, it is possible to prevent foreign matter from being caught. Moreover, since the gap α does not change, the inner part spherical cover 62 and the outer part spherical cover 63 hardly interfere with the lower leg link 33,
The movable range of the ankle joint 28 can be expanded.

Although the embodiments of the present invention have been described in detail, various design changes can be made in the present invention without departing from the gist thereof.

For example, in the embodiment, a rolling member 46 to which the foot portion 25 is integrally fixed is rotatably supported on the outer periphery of the rolling shaft portion 44, and a driving bevel gear 58 coaxially arranged in the pitching shaft portion 36; A driven bevel gear 57 coaxially disposed in the shaft portion 44 and connected to the rolling member 46 is meshed with the
The pitching shaft 36 is rotated to pitch the foot 25, and the rolling motor 35 drives the bevel gear 58.
Is rotated to rotate the foot portion 25. A pitching member (corresponding to the rotating member according to the third aspect of the invention) in which the foot portion 25 is integrally fixed is rotatably supported on the outer periphery of the pitching shaft portion 36, A drive bevel gear 58 coaxially arranged in the rolling shaft 44 and a driven bevel gear 57 coaxially arranged in the pitching shaft 36 and connected to a pitching member mesh with each other. To rotate the foot 25,
The drive bevel gear 58 may be rotated by the pitching motor 34 to pitch the feet.

In the embodiment, the load applied to the foot 25 is 6
Although the detection is performed by the component force sensor 60, a sensor capable of detecting three to five component forces can be used instead.

[0043]

As described above, according to the first aspect of the present invention, the pitching motor for pitching the foot around the left-right axis and the rolling motor for rolling the foot around the front-rear axis are provided. Since the lower leg is supported above the joint, the positions of the pitching motor and the rolling motor, which are heavy objects, are closer to the knee joint, and the moment of inertia of the lower leg around the knee joint is reduced, thereby driving the knee joint. The load on the driving source can be reduced.

According to the second aspect of the present invention,
Belt transmission means for pitching, which supports the foot in a rotatable manner via a rolling mechanism on a pitching shaft that is rotatably supported on the lower leg around the left and right axis, and transmits the rotation of the output shaft of the pitching motor to the pitching shaft. Since the pitching shaft is driven through, the rolling mechanism and the foot can be pitched integrally by rotating the pitching shaft, and the foot can be rolled with respect to the pitching shaft by operating the rolling mechanism. It is possible to prevent the pitching and rolling of the foot from interfering with each other.

According to the third aspect of the present invention,
A rotatable member integrally provided with a foot portion is rotatably supported on one outer periphery of a pitching shaft portion and a rolling shaft portion fixed so as to be orthogonal to each other, and inside the other of the pitching shaft portion and the rolling shaft portion. A driving bevel gear coaxially arranged is meshed with a driven bevel gear coaxially arranged inside one of the pitching shaft portion and the rolling shaft portion and connected to the rotating member, and the pitching shaft portion and the rolling shaft are rotated by the first drive source. Since the other of the sections is rotated and the drive bevel gear is rotated by the second drive source, pitching and rolling of the feet can be performed independently without affecting each other. Moreover, since the positions of the rolling shaft and the pitching shaft can be lowered,
The compliance control of the ankle joint can be realized with a smaller control amount, and stable walking can be enabled in response to unexpected irregularities or inclination of the floor surface.

According to the invention described in claim 4,
A rolling member integrally provided with a foot portion is rotatably supported on an outer periphery of a rolling shaft portion fixed so as to be orthogonal to the pitching shaft portion, and the rotation of the output shaft of the motor for rolling,
Rolling belt transmission means, a drive bevel gear coaxially disposed in the pitching shaft portion, and a driven bevel gear coaxially disposed in the rolling shaft portion transmit to the rolling member, thereby affecting pitching of the foot portion. The feet can be rolled independently without any
In addition, it is possible to freely pitch while keeping the foot in a rolled state. In addition, because the position of the rolling shaft and pitching shaft can be lowered, compliance control of the ankle joint can be achieved with a smaller control amount, and it is stable in response to unexpected irregularities or inclination of the floor surface Walking can be made possible.

According to the invention described in claim 5,
Since the pitching speed reducer is arranged between the pitching belt transmission means and the pitching shaft portion, the load on the pitching motor can be reduced, and the rolling speed reducer is arranged between the driven bevel gear and the rolling member. The load on the motor can be reduced.

According to the invention described in claim 6,
Since a predetermined gap is formed between the partial spherical cover that covers the outside of the rolling member and the lower end of the lower leg link, a large gap is generated between the partial spherical cover and the lower leg link even when the feet are pitched and rolled. Can be effectively prevented from being trapped by foreign substances.

According to the seventh aspect of the present invention,
Since the center of the partial spherical cover is on the pitching shaft or rolling shaft, the gap generated between the partial spherical cover and the lower leg link when the foot is pitched or rolled is kept constant, and the partial spherical shape The cover can be prevented from interfering with the lower leg link, and the movable range of the ankle joint can be expanded, and the trapping of foreign matter can be more effectively prevented.

According to the invention described in claim 8,
Since the positions of the pitching motor and the rolling motor are far from the foot, the sensor provided on the foot is less affected by the noise of the motor, and the detection accuracy of the sensor is improved.

[Brief description of the drawings]

FIG. 1 is a front view of a legged mobile robot.

FIG. 2 is a right side view of the legged mobile robot.

FIG. 3 is an enlarged sectional view taken along line 3-3 of FIG. 2 (sectional view taken along line 3-3 of FIG. 4);

FIG. 4 is a sectional view taken along line 4-4 in FIG. 3;

FIG. 5 is a perspective view of a lower leg and a foot.

FIG. 6 is an explanatory view of the action of pitching of the foot.

FIG. 7 is an explanatory view of the operation of rolling the foot.

[Explanation of symbols]

23 Upper leg part 24 Lower leg part 25 Foot part 27 Knee joint 28 Ankle joint 33 Lower leg link 34 Pitching motor (first drive source) 34a Output shaft 35 Rolling motor (second drive source) 35a Output shaft 36 Pitching shaft Part 42 Belt transmission means for pitching 43 Reduction gear for pitching 44 Rolling shaft part 46 Rolling member (rotating member) 55 Belt transmission means for rolling 57 Driven bevel gear 58 Drive bevel gear 59 Reduction gear for rolling 60 6 Force sensor (sensor) 61 Rolling Mechanism 62 Inside partial spherical cover (partial spherical cover) 63 Outside partial spherical cover (partial spherical cover) Ly Left / right axis Lx Front / rear axis α Gap

Claims (8)

[Claims] 1. A knee joint (27) at a lower end of an upper leg (23).
The lower leg (24) is connected to the lower leg (24) via an ankle joint (28), and the ankle joint (28) is connected to the lower leg (24). On the other hand, it is a leg structure of a legged mobile robot that supports the foot (25) so as to be able to freely pitch around the left-right axis (Ly) and freely rolls around the front-rear axis (Lx). Pitching motor (34) for pitching the left and right axes about the left-right axis (Ly) is supported on the lower leg (24) above the ankle joint (28), and the foot (2
5) A leg structure of a legged mobile robot characterized in that a rolling motor (35) for rolling around (5) around a longitudinal axis (Lx) is supported on a lower leg (24) above an ankle joint (28). 2. An output of a pitching shaft (36) rotatably supported on a lower leg (24) around a left-right axis (Ly), and a pitching motor (34) arranged in the left-right axis (Ly) direction. Pitching belt transmission means (4) for transmitting the rotation of the shaft (34a) to the pitching shaft portion (36).
2. The leg of the legged mobile robot according to claim 1, further comprising: (2) a rolling mechanism (61) that rotatably supports the foot (25) on the pitching shaft (36). Construction. 3. A knee joint (27) at the lower end of the upper leg (23).
The lower leg (24) is connected to the lower leg (24) via an ankle joint (28), and the ankle joint (28) is connected to the lower leg (24). On the other hand, this is a leg structure of a legged mobile robot that supports the foot portion (25) so as to be able to pitch around the left-right axis (Ly) and freely rolls around the front-rear axis (Lx), and is orthogonal to each other. And a pitching shaft portion (36) and a rolling shaft portion (44) that rotate around the left-right axis (Ly) and the front-rear axis (Lx), respectively.
And a pitching shaft (36) and a rolling shaft (44).
A rotating member (46) rotatably supported on one outer periphery of the shaft and rotating integrally with the foot (25); a pitching shaft (36) and a rolling shaft (44).
A first drive source (34) for rotating the other of the above, a pitching shaft (36) and a rolling shaft (44)
Drive bevel gear (5
8) and a pitching shaft (36) and a rolling shaft (44).
The drive bevel gear (5
8) a driven bevel gear (57) meshed with the rotating member (46) and connected to the rotating member (46); and a second drive source (35) for rotationally driving the drive bevel gear (58). Leg structure of mobile robot. 4. A knee joint (27) at the lower end of the upper leg (23).
The lower leg (24) is connected to the lower leg (24) via an ankle joint (28), and the ankle joint (28) is connected to the lower leg (24). On the other hand, it is a leg structure of a legged mobile robot that supports the foot (25) so as to be able to pitch freely around the left-right axis (Ly) and freely rolls around the front-rear axis (Lx), and comprises a pitching shaft (36). The rolling mechanism (61) for supporting the foot (25) in a freely rolling manner is provided integrally with the rolling shaft (44) fixed perpendicular to the pitching shaft (36) and the foot (25). A rolling member (46) fixed and rotatably supported on the outer periphery of the rolling shaft (44); a drive bevel gear (58) coaxially disposed in the pitching shaft (36); and a left-right axis (Ly). Arranged in the direction Rolling belt transmission means for transmitting the output shaft of the-ring motor (35) rotation (35a) on the drive bevel gear (58) (5
5), and are arranged coaxially in the rolling shaft portion (44) to mesh with the drive bevel gear (58) and to form the rolling member (4).
And a driven bevel gear (57) connected to (6). 5. A pitching speed reducer (43) is arranged between a pitching belt transmission means (42) and a pitching shaft (36), and a rolling speed reducer is provided between a driven bevel gear (57) and a rolling member (46). The leg structure of the legged mobile robot according to claim 4, wherein (59) is arranged. 6. The rolling member (46) is covered with a partially spherical cover (62, 63) outside, and the lower end of a lower leg link (33) forming a skeleton of the lower leg (24) and a partially spherical cover (62, 63). The leg structure of a legged mobile robot according to claim 4 or 5, wherein a predetermined gap (α) is formed between the legged mobile robot and (63). 7. The legged mobile robot according to claim 6, wherein the partial spherical cover (62, 63) has a center on the pitching shaft (36) or on the rolling shaft (44). Leg structure. 8. The sensor according to claim 1, wherein the foot is provided with a sensor for detecting a load applied to the foot. Leg structure of a legged mobile robot.