JPH06102307B2 - Robot leg mechanism - Google Patents

Description

The present invention relates to a leg mechanism of a so-called bipedal walking robot.

[Conventional technology]

2. Description of the Related Art Conventionally, there is known a robot in which a standing posture is maintained by two legs and the legs can move.

[Problems to be Solved by the Invention] However, there are few conventional walking robots that take a walking form in a strict sense even if they walk on their legs.
For example, in most cases, traveling wheels or the like are provided at the lower ends of the legs, so to speak, so that they can move by rotation of the wheels.

Further, even if it can be said to be a traveling type, there are almost no ones who walk by raising a portion corresponding to a person's foot like when a person walks.

In robots, if there is something that can walk while lifting the part corresponding to the foot, even if there is a step or a step, there is a special walking structure, such as a caterpillar or planet wheels. Is unnecessary.

[Means for Solving the Problems]

The present invention has been made in view of the above-mentioned current situation of so-called walking robots, and an object thereof is to provide a leg mechanism capable of walking in a manner very similar to a walking manner of a person. 1st, 3rd link and 2nd parallel,
A parallelogram link formed by a fourth link in a longitudinal direction and pivotally attached at four corners, wherein the extension is between the lower end of the first link and the rear end of the second link and the outer end thereof. The intersection point where the line segment connecting the set rear end of the second link and the both ends of the first and second links intersects with the fourth link parallel to the second link or the extension of the fourth link is straight. The pantograph-like link mechanism formed so as to be on the line is formed into one leg member by being supported and guided by the vertical guide and the horizontal guide formed on the bracket at the intersection of the second link extension rear end and the intersection. The two members are arranged parallel to each other in their vertical planes, and both brackets are pivotally attached by a vertical axis so that they can move relative to each other in a plane.
A foot member link pivotally attached to the lower end of the link and having a posture maintained in a predetermined direction via a sub-link parallel to the first link and a sub-link parallel to the second link or the fourth link, and The driving force acting in the direction of movement of the bracket is transmitted to the part supported by the guide of the bracket and the pivotally connecting part between the brackets.

[Action]

In the leg member using the pantograph-like link mechanism, the operation of the rear end portion of the second link extended by the vertical and horizontal guides of the bracket and the intersection of the third and fourth links is Corresponding to the contact of the legs, the whole leg member is rocked back and forth.

Similarly, the pivot joints of the first link and the second link correspond to the knees of a person's leg, so to speak, and cause the leg member to perform a bending operation.

Further, the foot member whose posture is maintained in a predetermined direction by the sub-link maintains the standing posture of the entire robot in a predetermined posture regardless of the degree of leg openness.

〔Example〕

In FIG. 1, L is a leg member mainly formed of a pantograph-like link mechanism, which is constructed as follows.

Thus, reference numeral 1 is a first link arranged in a substantially vertical posture, and the lower end side is formed in the extension portion 1a. 2 is a second link pivotally attached P ₁ at the upper end of the first link and its tip, 3
The third was the upper pivot P ₂ at the rear side of the second link
A link, parallel to the first link.

Reference numeral 4 denotes a fourth link which is parallel to the second link 2 and whose tip is pivotally attached to the first link 1 and rear end to the lower end of the third link 3, respectively.
It is a link. Each of the links 1 to 4 forms a parallelogram link at each of the pivot points P _{1 to} P ₄ . Further, in each of the above-mentioned links, the extended lower end 1b of the first link 1, the pivotal connection portion P _{4 of} the third link 3 and the fourth link 4, and here the extended rear end 2b of the second link 2 are , On a virtual line segment 1 connecting the lower end 1b and the rear end 2b. Then, each link thus formed constitutes a pantograph-shaped link mechanism.

In this embodiment, the link mechanism uses the pivotally connecting portion P ₄ as a fulcrum for the horizontal guide 5, and the extended rear end of the second link 2.
The vertical guides 6 are slidably supported along the respective guides with the point 2b as the force point. Hereinafter, the fulcrum will be described with reference numeral P ₄ and the power point with reference numeral 2b.

The guides 5 and 6 are attached to a bracket 7 having a surface including both guides or a surface parallel to this.

In addition, the fulcrum P ₄ and the force point 2b supported by the guides 5 and 6 described above.
In order to move, position, clamp, etc. the respective points in the respective guides 5, 6, they are connected to appropriate drive sources PV, PH by, for example, a motor or a drive cylinder.

The output of each drive source PV, PH is transmitted to the power point 2b and the fulcrum P ₄ by reciprocating motion along the guide direction on the respective guides 5, 6 via a transmission mechanism with or without a speed reducer or the like. I am doing it.

Reference numeral 8 is a link that is pivotally attached to the lower end 1b of the first link 1 and is held in a substantially horizontal posture in the link mechanism.
The posture of the link 8 is always kept horizontal by the sublinks 1A and 4A described below so that the link 8 functions as a foot of the robot.

In this embodiment, a first sub-link 1A having the same length and parallel to the first link 1 and a fourth sub-link 4A having the same length and parallel to the fourth link 4 are connected to connect both sub-links. It consists of link 8a and the lower end of the first sub-link 1A is link 8
And the rear end of the fourth sub-link 4A is a connecting link.
The horizontal guide 5 is integrated with the force point 2b of the fourth link 4 via 8b.
The link 8 can be maintained in a horizontal posture by being supported by.

Note that the structure for maintaining the posture of the link 8 in a predetermined manner is not limited to the above example.

Further, the link 8 serving as the foot is provided with a floor suction mechanism (not shown in the figure) using an electromagnet or the like.

Further, if necessary, the link 8 itself may have a link structure capable of expanding and contracting in the height direction with respect to the floor surface.

The leg members L in the leg mechanism of the present invention are configured by the above members 1 to 8.

The two leg members L are arranged side by side as shown in FIG. 2 and are connected to each other via the vertically oriented shafts 9 in the brackets 7, so that one leg member L is connected to the other leg member L. On the other hand, the shaft 9 can be rotated by a predetermined angle.

For convenience of description, in the drawings starting from FIG. 2, the other leg member will be described by adding a dash to the reference numeral of each member.

In the example shown in FIGS. 2A and 2B, the end sides (downward in the figure) of the brackets 7 and 7'are pivotally attached by the shaft 9, but the pivotal attachment position is not limited to this. For example, the brackets 7 and 7'may be pivotally attached to the opposite side surfaces. Reference numeral 7a is a pivotally mounted bracket portion formed on the rear surface of the bracket 7,7 'as a pivotally attached portion of the shaft 9.

The brackets 7 and 7 are swung by a drive cylinder, a motor and a crank mechanism, but here, two motor cylinders PT and PT 'are arranged with their rear ends on the shaft 9 side and their respective tips. Connect to the sides of brackets 7 and 7 ',
The T and PT's are expanded and contracted to make a turn.

An example of the leg mechanism of the present invention is configured as described above,
This leg mechanism supports the upper body of the robot, so I will touch on this point.

FIG. 3 is a side view schematically showing an example of a robot equipped with the leg mechanism of the present invention.

In FIG. 3, 10 is a bracket 7 in the leg mechanism,
On the upper surface side of 7 ', a supporting substrate of the upper half body UB mounted and supported by the brackets 7 and 7', and pivotally attached coaxially with the shaft 9 described above.
In addition, it has an arcuate guide portion 10b centering on the shaft 9 for guiding the brackets 7 and 7'rotating about the shaft 9.

Thus, the lower body UB of the robot is mounted such that the lower surface side of the connecting substrate 11 provided therein can be swiveled on the support base 10 and can be slid to the left and right by a small amount when viewed from the front.
The drive source for the turning and the lateral movement is not supported but is provided separately.

In FIG. 3, 12 is a bracket to which an arm mechanism AP using a pantograph link mechanism is attached, 13 is a head, and 14 is an upper body cover, which are mounted and supported on the connection board 11.

Next, an example of the operation of the leg mechanism of the present invention configured as described above will be described with reference to FIG.

FIG. 4 shows the framework of the leg mechanism of the present invention in a walking state.

It is now assumed that the upper body UB of the robot and the load W associated therewith are supported by the two leg members L, L'in the state shown in the figure. Here, the line of action of the load W is assumed to be on a line that bisects the apex angle between the imaginary line segments l and l'of the leg members L and L '.

In order for the robot to walk forward in this state, the leg member L ′ located at the rear (right side in the figure) performs a walking motion, and at the same time, the leg member L side performs a posture correction motion in synchronization with this walking motion. To do.

First, the leg member L'lifts the link 8'from the floor surface and advances it forward.

The lifting operation of the link 8'is performed by moving the force point rear end 2b 'of the second link positioned on the straightness guide 6'downward.

In parallel with this operation, the fulcrum P ₄ ′ is moved forward in the horizontal guide 5 ′ (leftward in the figure), so that the link 8 ′ moves forward.

On the other hand, when the operation of the leg member L ', the leg member L is and link 8 of its legs is secured to the floor, moving the fulcrum P ₄ while positioning the emphasis 2b rearward (right in the drawing).

Here, the rearward movement of the fulcrum P ₄ of the leg member L is such that, before the landing of the leg member L ′ foot link 8 ′, the virtual line segment 1 of the link mechanism L is not located behind the line of action of the load W. For example, the action line and the line segment 1 are matched.
This backward movement of the fulcrum P ₄ causes the forward movement of the bracket 7 relatively because the foot link 8 is fixed to the floor.

On the other hand, where the forward movement of the 'fulcrum P _4' in the leg member L has exceeded the fulcrum P ₄ of the fulcrum P ₄ 'leg member L, the force point
2b 'is moved up to the same position as the force point 2b to land the foot link 8', and the force point 2b 'is positioned and clamped. Movement of the 'fulcrum P ₄ by the landing of the' link 8 is stopped.

Then, the backward movement of the fulcrum P ₄ , that is, the relative forward movement of the bracket 7 is continued even after the straight landing of the link 8'is completed.
This continues until the line of action of the load W is reached between the line segments l, l'of the link mechanism, preferably until the positional relationship opposite to the state shown in FIGS.

With the above operation, the positional relationship between the two leg members L and L'before and after is in a state opposite to that in FIG. In other words, the entire robot has moved forward (to the left in the figure) with respect to the foot link 8 that remains fixed during the above operation.

Therefore, by repeating the above operation, the leg of the present invention can walk forward.

In the above-mentioned motion for walking, the force points 2b and 2b ′ of the leg members L and L ′ are alternately moved up and down, and the fulcrums P ₄ and P _4
The motion pattern for 4'advancing and retreating synchronously can be stored in a computer or the like in advance and automatically executed.

Incidentally, the adsorbing means by the electromagnet or the like of the leg links 8, 8'of the leg members L, L ', of course, controls the opening and closing of the operation of the electromagnets, etc. in accordance with the detaching and attaching operation of the links 8, 8'. Is.

Further, the direction change of the robot in the walking state is such that the leg member L or L'on the side to be bent is lifted up and the bracket 7 or 7'of the leg member L or L'is centered around the shaft 9. The foot link 8 or 8'is landed by rotating the necessary angle, and then the other leg member L'or L '
The robot is turned to the side by performing the same operation as above.

Here, the guide portion 10b of the support substrate 10 provided on the brackets 7 and 7'for supporting the upper body UB of the robot has a stopper (shown in the figure) that restricts the swing of the brackets 7 and 7'inward and outward on the arc circumference. No) is provided.

Therefore, in the above turning operation, when the turning angle is maximized, for example, the first turning bracket is moved to the guide portion 10.
The support substrate 10 pivots until it comes into contact with the stopper on the outer side of b, and the bracket that pivots later pushes the stopper on the inner side of the guide portion 10b, so that the support substrate 10 pivots together with the bracket that pivots later. The upper body UB also turns with this turning.

Next, the walking of the step by the leg mechanism of the present invention will be described with reference to FIG.

Even when walking on a stepped part or stairs, the leg member L,
The operation mode of L'is basically the same as walking on a flat surface.

However, when the landing position of the foot link 8 or 8 ′ that has been lifted and advanced is higher than the original position or the position of the foot link of another leg member, the leg member of the foot link that has been lifted and advanced. As an example, the positioning of the force point of is adjusted as follows.

Now, when both leg members L, L'are in the posture shown by the solid line in FIG. 5, it is assumed that there is a step in front.

First, 'with lifted is, the fulcrum P ₄ retracts and the leg member L of the leg members L' leg members L 'bracket 7,7 connected by forward movement of the' fulcrum P ₄ of moves forward. Here, the force point 2b 'of the leg member L'is guided in the guide 6'until the foot link 8'swing forward of the lifted leg member L'lands on the raised (or lowered) floor surface. Moved and positioned. Where bracket 7,
The height of 7 'itself remains the same. The heights of the brackets 7 and 7'are unchanged because the height of the power point 2b of the other leg member L has not changed at this point.

Then, when the force point 2b 'is positioned in the above, the heights of the brackets 7 and 7'are maintained and restrained by the leg members L'with their original heights (Fig. 5). (Indicated by the chain line).

Next, the leg member L having the foot link 8 remaining in the lower position (or higher position) is moved to a position at the same height as the leg member L '.

The movement of the leg member L here is basically the same as the case of walking, and while lifting the foot link 8 in the same manner, that is, the force point 2b.
While moving down, move the fulcrum P ₄ forward. During this period, since the load W of the robot is supported by the other leg member L ', the fulcrum on the leg member L'side due to the movement of its center of gravity.
P ₄ ′ is retracted, that is, the brackets 7 and 7 ′ are relatively advanced. As a result, the entire leg mechanism can be moved to the step side.

The movement of the center of gravity with respect to the leg members L, L'of the robot is often required not only in the front-back direction but also in the left-right direction.

In the present invention, the movement of the center of gravity of the upper body of the robot with respect to the left and right is performed by, for example, swinging the entire upper body UB to the left or right with respect to the center line on the mounting substrate 11, or by landing the action line of the center of gravity of the upper body. It is carried out by moving so as to coincide with the line segment 1 or 1'of the leg member on the side where it is located. Of course, the movement of the center of gravity in the front and rear may be performed by means other than the above example.

〔effect〕

The present invention is as described above, using two sets of pantograph-like link mechanisms as a leg member of a robot, and supporting points and force points of each link mechanism are respectively supported by vertical and horizontal guides of a bracket, and Since these brackets are connected to each other to form a leg mechanism, the leg mechanism performs a walking motion similar to that of a human leg, and if it is a multi-joint leg capable of such motion, the drive source is the guide of the bracket. Fulcrum supported by
A special effect is obtained in that only three types are required, one for power point and one for turning motion.

As described above, the present invention is extremely useful as a leg of a so-called bipedal robot.

[Brief description of drawings]

FIG. 1 is a side view of an example of a link mechanism that constitutes a leg member in the leg mechanism of the present invention, FIG. 2 is a plan view of an essential part of the leg mechanism of the present invention, and FIG. 3 is an example of the leg mechanism of the present invention. FIG. 4 is a side view of a walking type robot, FIG. 4 is a side view showing a walking state of an example of a leg mechanism of the present invention, and FIG. 5 is a side view of another example. 1 ... 1st link, 2 ... 2nd link, 3 ... 3rd link, 4 ... 4th link, 2b ... Extension end of 2nd link (power point), P ₄ ... 3rd link Pivoting part (fulcrum) of the 4th link, 5 ... Horizontal guide, 6 ... Vertical guide, 7 ... Bracket, 8 ... Foot link, 9 ... Bracket 7,7 'connecting shaft, 10 ... Support Base, 10a …… Mounting shaft, 10b …… Bracket rotation guide, 11 …… Mounting board, 13 …… Head, 14
…… Body, L, L ′ …… Leg member, PV, PH, PT …… Drive source

Claims (1)

[Claims] 1. Parallel first and third links and parallel second and fourth links.
A parallelogram link formed by linking in a longitudinal direction and pivotally attached at four corners, which is arbitrarily set between the extension lower end of the first link and the rear end of the second link and its extension outer end. The second link extension rear end and the first and second
The pantograph-shaped link mechanism is formed such that a line segment connecting the both ends of the second link intersects a fourth link parallel to the second link or an extension of the fourth link on a straight line. A vertical guide and a horizontal guide formed on a bracket at the intersection of the rear end portion of the two-link extension are supported and guided to form one leg member, and the two leg members are
While arranging each bracket in parallel in the vertical plane,
The two brackets are pivotally attached to each other by a vertical axis so that they can be angularly moved relative to each other in a plane, while the sublink and the second link are pivotally attached to the lower end of the first link of the leg member and parallel to the first link. Alternatively, a foot member link whose posture is maintained in a predetermined direction is attached via a sub-link parallel to the fourth link, and they are attached to a portion supported and guided by the guide of the bracket and a pivotally connecting portion between the brackets. A leg mechanism of a robot, characterized in that the driving force acting in the motion direction of the robot is transmitted.