JP2006218550A - Foot part structure of bipedal walking robot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a foot part structure of a bipedal walking robot capable of stably walking even when such force to fall a foot outside is generated in non-leveled ground walking, etc. <P>SOLUTION: A sole part 12 of a lower part of a foot part 11 is formed in a shape or of a material on which reaction force from an outside part becomes larger than that from an inside part on the inside and outside of a sole when it grounds. For example, the sole part 12 is constituted by arranging a hard rubber plate 31 on the outside part on the inside and outside of the sole and a soft rubber plate 32 on the inside part. A robot is made to maintain stable walking by balancing it by largely applying the reaction force from the outside part of the sole against force working on the sole so that the sole is inclined to the outside and force to fall the foot outside can be hardly generated when the sole part 12 of the walking robot grounds. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a foot structure of a legged walking robot, and more particularly to a foot structure of a biped walking robot having a sole that has improved walking stability.

Legged walking robots, especially biped robots, are difficult to improve walking stability. To achieve this, the following structure has been proposed for the robot foot (the part below the ankle). .
In other words, the heel of the foot is composed of a hard member and a soft member filled therebetween, and its cross-sectional shape is formed in a comb-like shape, which is highly rigid against force from the direction of gravity. A foot structure has been proposed in which the rigidity is low with respect to the force from the direction (see, for example, Patent Document 1).

JP 2001-129774 A

However, the above prior art has the following problems.
In the conventional technology, when focusing on the sole, the same elastic body is attached to the entire surface of the inside and outside of the sole (the side corresponding to the thumb of the sole and the side corresponding to the little finger). It was. In other words, the sole is formed so that the inside and outside of the foot are bent almost evenly, and the ease of falling to the inside and outside of each of the left and right feet when the foot (sole) is grounded is equal on both the inside and outside.

By the way, in the case of a biped robot, walking stability when the body / foot falls to the outside (points to the right of the right foot when touching the right foot and to the left of the left foot when touching the left foot) when touching the foot. It becomes difficult to maintain. On the other hand, when the body / foot falls inward, stability can be maintained relatively easily, for example, by coordinating the foot on the opposite side of the foot falling inward. Therefore, you should avoid falling down as much as possible.
In the case of leveling walking, it is easy to perform walking as planned, so it does not matter so much, but in the case of uneven level walking, the disturbance acting on the sole from the ground increases when touching the foot, It becomes more difficult to stabilize walking.
In the prior art, the structure in which the ease of falling to the inside and outside of each left and right foot when touching the foot is the same on both the inside and outside sides, so the direction in which the disturbance acts is the same on both the inside and outside sides. There is a problem that the direction of falling is equal on both the inside and outside of the sole, and the probability that the walking becomes unstable becomes considerably high.

  The present invention has been made to solve the above-described problems of the prior art, and an object thereof is to provide a foot structure of a biped robot that can improve walking stability.

In order to achieve the above object, the foot structure of the biped walking robot according to claim 1 of the claims has a greater reaction force from the outer part than the inner part inside and outside of the sole when touched. It is characterized by comprising a sole part formed of shape and / or material.
The invention according to claim 2 of the claims is the invention according to claim 1, wherein the sole has an elastic body layer on an outer portion inside and outside the sole, and the outer portion is an inner portion. It is characterized in that it is protruded downward.
The invention according to claim 3 of the claims is the invention according to claim 1, wherein the sole has a hard elastic layer on the outer part inside and outside the sole, and on the inner part. It has a soft elastic layer.
The invention according to claim 4 of the claim is the invention according to claim 1, wherein the sole has an elastic layer in which a notch is formed in an inner portion of the inside and outside of the sole. It is characterized by.
The invention according to claim 5 of the claims is the invention according to claim 1, wherein the sole portion has a structure of the foot portion so that the outer portion inside and outside the sole is lower than the inner portion. It is characterized by being protruded.
The invention according to claim 6 of the present invention is the invention according to claim 5, wherein the outer part on the inner side and the outer side of the sole is formed on the inner part by protruding downward from the inner part. A soft elastic layer is attached and fixed to the recessed portion.

In the first aspect of the present invention, the sole portion is formed in a shape and / or material in which the reaction force from the outer portion is larger than the inner portion on the inner and outer sides of the sole. According to this, even when walking on rough terrain where a force such that the sole of the foot tilts outward and falls when touching the foot is allowed, the robot can walk without degrading stability, and walking with a biped robot Stability can be improved.
According to the invention described in claim 2 of the claims, the effect of the invention described in claim 1 can be obtained with a simple configuration in which an elastic body layer is provided.
Similarly, according to the invention described in claim 3, the effect of the invention described in claim 1 can be obtained with the ground contact area of the sole portion being widened.
Similarly, according to the invention described in claim 4, an effect similar to that of the invention described in claim 3 can be obtained with a simple configuration in which an elastic body layer is provided.
Similarly, according to the invention described in claim 5, the effect of the invention described in claim 1 can be obtained without using a member other than the foot structure.
Similarly, according to the invention described in claim 6, the effect of the invention described in claim 1 can be obtained with the ground contact area of the sole portion widened and the elastic layer held firmly.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol shows the same or an equivalent part between each figure.
FIG. 1 is a diagram showing an example of a biped walking robot to which the present invention is applied.
As shown in the figure, the bipedal walking robot is composed of two legs (legs) 1, a torso 2 above the legs 1, a head 3 above the torso, and arms 4 on the left and right sides of the torso. To do. The back of the body 2 is provided with a control unit for a plurality of joint driving motors (not shown) for connecting the robot units 1 to 4 and the like, and a storage unit for battery power. This storage part is hidden by the body 2 in FIG.

Here, a foot portion 11 that is grounded (landed) during walking is attached to the lower portion of the foot 1, and the present invention relates to the structure of the foot portion 11. That is, the foot portion 11 according to the present invention has a sole portion 12 formed of a shape and / or material in which the reaction force from the outside portion is larger than the inside portion of the inside and outside of the foot when the foot (sole) is grounded. It is equipped with.
According to this, a force that causes the foot 1 to always fall to the inside (points to the left side of the right foot when touching the right foot and to the right side of the left foot when touching the left foot) is generated when the foot is touched. Since the reaction force acts so as not to generate a force that falls outside, the walking stability of the robot is improved.

Hereinafter, some embodiments of the present invention will be described.
2A and 2B are views showing a first embodiment of the foot structure of the biped robot of the present invention, in which FIG. 2A is a front view and FIG. 2B is a bottom view (foot sole view).
As shown in the figure, in the first embodiment, the sole portion 12 has an elastic body layer, here, a rubber plate 21 in the outer portion on the inner and outer sides of the sole, and the outer portion protrudes downward from the inner portion. Become.
Specifically, the sole portion 12 has a rubber plate 21 having an appropriate thickness only on the outer portion (outer half of the sole) from the center in the inside / outside direction of the sole. The structure is affixed to the bottom surface 11b of the structure 11a, and the outer portion protrudes downward from the inner portion by the thickness of the rubber plate.
As shown in FIG. 1, the bipedal walking robot has two legs 1 and 1, and the above configuration is similarly applied to each leg 1 (each leg 11 and sole 12). Of course. The same applies to the following embodiments.
In the figure, 20 indicates the walking ground of the robot, and G indicates the center of gravity when the robot is stationary. A two-dot chain line arrow a indicates a static moment acting on the foot 1 in the illustrated configuration.

FIGS. 3A and 3B are diagrams showing a second embodiment of the foot portion of the biped robot of the present invention, where FIG. 3A is a front view and FIG. 3B is a bottom view.
As shown in the figure, in the second embodiment, the sole portion 12 has a hard elastic layer, here a rubber plate 31, on the outer portion inside and outside the sole, and the hard rubber plate 31 on the inner portion. It has a soft elastic layer of the same thickness, here a rubber plate 32.
Specifically, the sole portion 12 has a structure of the foot portion 11 made of iron, aluminum, or the like with a hard rubber plate 31 having an appropriate thickness from an approximately center to an outer portion (outer half of the sole) in the inner and outer directions of the sole. A soft rubber plate 32 having the same thickness as the hard rubber plate 31 was attached to the bottom surface 11b of the structure 11a on the inner surface (inner half of the sole). It has a structure.
Since the hard rubber plate 31 and the soft rubber plate 32 have the same thickness as described above, there is no step between the inside and outside of the sole in the second embodiment.

4A and 4B are diagrams showing a third embodiment of the foot portion of the biped robot of the present invention, in which FIG. 4A is a perspective view seen from the bottom side, and FIG. 4B is a bottom view.
As shown in the figure, in the third embodiment, the sole portion 12 includes an elastic body layer, in this case, a rubber plate 42, in which a notch portion 41 is formed in an inner portion on the inside and outside of the sole.
Specifically, the foot portion 12 is formed of a rubber 42 plate having an appropriate thickness having a notch portion 41 at a position corresponding to the arch of the inner portion of the inside and outside of the sole, and the bottom surface 11b of the structure 11a of the foot portion 11. It has a structure pasted on.

FIG. 5 is a front view showing a fourth embodiment of the foot part of the biped robot of the present invention.
As shown in the figure, in the fourth embodiment, the sole portion 12 has a structure 11a of the foot portion 11 so that an outer portion on the inner and outer sides of the sole protrudes downward from the inner portion.
Specifically, in the sole 12, the structure 11 a of the foot 11 protrudes downward from the center (in the outer half of the sole) from the center in the inside / outside direction of the sole. The inner half of the back has a structure that is an empty space (dent 51).
This fourth embodiment is similar to the first embodiment shown in FIG. 2, but nothing is attached to the bottom surface 11b of the structure 11a of the foot 11, and is formed, for example, when a foot structure of a robot is molded. It has a structure.

FIG. 6 is a front view showing a fifth embodiment of the foot portion of the biped robot of the present invention.
As shown in the figure, in the fifth embodiment, the sole portion 12 has the same thickness d1 (= h1) as the recessed dimension h1 in the recessed portion 51 formed on the inner half of the sole in the fourth embodiment described above. A soft elastic body layer, here, a rubber plate 61 is attached and fixed (attached to the peripheral wall of the recessed portion 51).
That is, the structure 11a of the hard foot portion 11 made of iron, aluminum or the like is left as it is from the center to the outer side in the inner side of the sole, and the soft rubber plate 61 is stepped between the inner and outer sides of the sole. The structure is affixed with a thickness d1 (= h1) that does not occur, and is similar to the second embodiment shown in FIG.

According to each of the above-described embodiments, when the foot is in contact with the robot during walking, a force is generated so that the sole always tilts inward, that is, a force that causes the foot 1 to always fall inward (at least the force to fall outward). Since the reaction force from the outer part of the sole acts (so that it does not easily occur), the walking stability of the robot is improved.
In particular, according to the first embodiment shown in FIG. 2, the bottom surface 11b of the structure 11a of the foot 11 may be a flat surface, and the present invention has a simple configuration in which only a flat rubber plate 21 is attached to the bottom surface 11b. Can be realized.
Further, according to the second embodiment shown in FIG. 3, the lower surface (sole) of the sole 12 is a flat surface, and the present invention can be realized while the ground contact area of the sole 12 is widened.
Further, according to the third embodiment shown in FIG. 4, the present invention is realized in an intermediate form in the first and second embodiments with respect to the contact area of the sole portion 12 and the reaction force from the sole outer portion. it can.
Moreover, according to 4th Embodiment shown in FIG. 5, this invention is realizable, without using members other than the structure 11a of the foot part 11. FIG.
Furthermore, according to the fifth embodiment shown in FIG. 6, the present invention can be realized while the ground contact area of the sole 12 is kept wide. Moreover, since the rubber plate 61 is affixed on the two surfaces of the structure 11a of the foot 11 made of iron, aluminum, etc., the affixing strength of the rubber plate 61 can be increased.

  In the above-described embodiment, the rubber plate is used as the elastic body layer provided on the sole, but other elastic bodies, for example, an elastic body made of synthetic resin may be used. In short, when the robot's sole is in contact with the ground, select a material that has a greater reaction force from the outside than the inside inside / outside of the sole. It is sufficient to select a material having higher rigidity.

It is a figure which shows an example of the bipedal walking robot with which this invention is applied. It is a figure which shows 1st Embodiment of the foot | leg part structure of the biped walking robot of this invention. It is a figure which similarly shows 2nd Embodiment. It is a figure which similarly shows 3rd Embodiment. It is a figure which similarly shows 4th Embodiment. It is a figure which similarly shows 5th Embodiment.

Explanation of symbols

1: foot of biped robot, 11: foot, 11a: foot structure, 12: sole, 21: rubber plate (elastic body layer), 31: hard rubber plate (hard elastic body layer), 32: Soft rubber plate (soft elastic layer).

Claims (6)

  A foot part structure of a biped robot, comprising a foot part formed of a shape and / or a material in which a reaction force from an outer part is larger than an inner part inside and outside the sole when touched.   The foot structure of the biped robot according to claim 1, wherein the sole includes an elastic layer in an outer portion on the inner and outer sides of the sole, and the outer portion protrudes downward from the inner portion.   The foot structure of the biped walking robot according to claim 1, wherein the sole part has a hard elastic layer on an outer part inside and outside the sole and a soft elastic layer on an inner part.   The foot structure of the biped walking robot according to claim 1, wherein the sole includes an elastic layer in which a notch is formed in an inner portion on the inner and outer sides of the sole.   The foot structure of the biped walking robot according to claim 1, wherein an outer portion of the inner and outer sides of the sole protrudes downward from an inner portion of the sole portion by a structure of the foot portion. The biped walking robot according to claim 5, wherein a soft elastic body layer is attached and fixed to a recessed portion formed in the inner portion by projecting an outer portion on the inner and outer sides of the sole to a lower side than the inner portion. Foot structure.

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