JP2020183014A - Walking robot - Google Patents

Abstract

To provide a walking robot that allows reduction in inertial force of a leg part and thinning of the leg part.SOLUTION: An actuator 15 is arranged in a hip joint 11 of a walking robot 1. Rotation of the actuator 15 is transmitted to rotation of a foot part 6 via a first link device 21, a second link device 22 and a third link device 23. The first link device 21 is configured to rotate the first link device 31 about a first pitch shaft 11c of the hip joint 11 when the actuator 15 is rotated. The second rink device 22 is configured to rotate the second link 35 about a second pitch shaft 12a of a knee joint 12 when the first rink 31 is rotated. The third link device 23 is configured to rotate the foot part 6 about a third pitch shaft 13b when the second link 35 is rotated.SELECTED DRAWING: Figure 3

Description

The present invention relates to a walking robot, and more particularly to a walking robot that rotates a palm portion about a pitch axis of an ankle joint.

Development of walking robots that imitate the walking forms of humans and animals is underway. Patent Document 1 discloses a bipedal walking robot including an upper body and two left and right legs. The upper body and legs are connected via the hip joint. The legs include a femur link, a lower leg link, and a palm portion. The femoral link and the lower leg link are connected via a knee joint. The lower leg link and the palm of the foot are connected via an ankle joint. Bipedal walking is possible by rotating the thigh link, lower leg link, and palm with a plurality of actuators around each joint.

The palm portion is rotated around the pitch axis of the ankle joint by an actuator. When this actuator that rotates the palm is placed on the ankle joint, a large inertial force acts when the leg is moved at high speed. In order to solve this problem, in the invention of Patent Document 1, the actuator is arranged on the thigh link so that the driving force of the actuator is transmitted to the palm portion via the link device.

Japanese Unexamined Patent Publication No. 2011-224752

However, even in the walking robot described in Patent Document 1, when the legs are moved at high speed, there is still a problem that an inertial force acts on the legs, although it is smaller than when the actuator is arranged on the ankle link. Further, there is a problem that the legs become thick due to the arrangement of the actuators and the configuration of the link device.

Therefore, an object of the present invention is to provide a walking robot capable of reducing the inertial force of the legs and making the legs thinner.

In order to solve the above problems, in one aspect of the present invention, the thigh link is rotatably connected to the hip joint about the first pitch axis, and the lower leg link is rotatably connected to the thigh link about the second pitch axis. In a walking robot that is connected and the foot flat portion is rotatably connected to the lower leg link about a third pitch axis, the actuator arranged at the hip joint and the first link are the first link when the actuator is rotated. A first link device configured to be rotated around a one-pitch axis, and a second link configured to rotate the first link so that the second link can be rotated around the second pitch axis. It is a walking robot including a two-link device and a third link device configured so that when the second link is rotated, the foot flat portion is rotated about the third pitch axis.

According to the present invention, since the actuator that rotates the palm portion around the third pitch axis (pitch axis of the ankle joint) is arranged in the hip joint, it is possible to reduce the inertial force when moving the leg portion at high speed. it can. Further, since the rotation of the actuator is transmitted to the foot portion via the first link device, the second link device and the third link device, the first link device, the second link device and the third link device are transmitted to the hip joint and the thigh. It can be placed along the link and the lower leg link, and the legs can be made thinner.

It is a schematic diagram of the walking robot of one Embodiment of this invention. It is a perspective view of the leg part of this embodiment. It is a side view of the leg part of this embodiment. It is an operation diagram of the leg part of this embodiment (FIG. 4 (a) shows the state which made the foot part parallel to the ground, and FIG. 4 (b) shows the state that the foot part is extended). It is a figure which shows the range of motion of the leg part of the comparative example (FIG. 5 (a) is a state which the leg part is extended, FIG. 5 (b) is a state which the leg part is folded). It is a figure which shows the range of motion of the leg part of this embodiment (FIG. 6 (a) is a state which the foot flat part is rotated to the same angle as FIG. 5 (b), and FIG. 6 (b) further holds the foot flat part. Rotated state). It is a figure which shows the range of motion of the 1st articulated link of this embodiment (FIG. 7 (a) shows the crescent-shaped first articulated link of this embodiment, and FIG. 7 (b) is the linear | linear first of the comparative example. 1 Indicates a concatenated link). It is a figure which shows the range of motion of the foot palm part of this embodiment. It is a figure which shows the range of motion of the foot part of this embodiment (FIG. 9A shows the state which the leg part is extended and the upper body is tilted forward, and FIG. 9B is the state where the leg part is extended and is upper. The state in which the body is upright is shown, and FIG. 9 (c) shows the state in which the legs are bent and stretched). It is a figure which shows the range of motion of the foot part of this embodiment (FIG. 10 (a) shows the state which the leg part was bent and the upper body was tilted forward, and FIG. Indicates that the body is upright).

Hereinafter, the walking robot according to the embodiment of the present invention will be described with reference to the accompanying drawings. However, the walking robot of the present invention can be embodied in various forms, and is not limited to the embodiments described in the present specification. The present embodiment is provided with the intention of allowing those skilled in the art to fully understand the scope of the invention by making sufficient disclosure of the specification.

FIG. 1 shows a schematic view of a walking robot 1 according to an embodiment of the present invention. Hereinafter, for convenience of explanation, the configuration of the walking robot 1 will be described with the traveling direction of the walking robot 1 as the X-axis direction, the left-right direction of the walking robot 1 as the Y-axis direction, and the vertical direction of the walking robot 1 as the Z-axis direction. Here, the X-axis is the roll axis, the Y-axis is the pitch axis, and the Z-axis is the yaw axis. Since the pair of left and right legs 3 are symmetrical, they are designated by the same reference numerals.

The walking robot 1 includes an upper body 2 and a pair of left and right leg portions 3 connected to a lower end portion of the upper body 2. Each leg 3 includes a femur link 4, a lower leg link 5, and a foot flat portion 6. The femur link 4 is connected to the upper body 2 via the hip joint 11 having three degrees of freedom. The lower leg link 5 is connected to the femur link 4 via a knee joint having one degree of freedom. The palm portion 6 is connected to the lower leg link 5 via an ankle joint having two degrees of freedom.

More specifically, the femur link 4 is rotatably connected to the upper body 2 about the first yaw axis 11a, the first roll 11b axis, and the first pitch axis 11c of the hip joint 11. The lower leg link 5 is rotatably connected to the femur link 4 about the second pitch axis 12a of the knee joint 12. A flat portion 6 is rotatably connected to the lower leg link 5 around a second roll shaft 13a and a third pitch shaft 13b of the ankle joint 13.

Since the leg portion 3 is configured as described above, the foot flat portion 6 has 6 degrees of freedom with respect to the upper body 2. By appropriately driving the joints 11, 12, and 13 of the leg portion 3, a predetermined movement of the leg portion 3 becomes possible, which enables the walking motion, the running motion, and the like of the walking robot 1.

Although not shown, a pair of left and right arms are attached to the left and right sides of the upper body 2. A head is attached to the upper end of the upper body 2.

The drive mechanism for rotating the foot flat portion 6 about the third pitch shaft 13b will be described in detail below. FIG. 2 shows a perspective view of the leg portion 3, and FIG. 3 shows a side view of the leg portion 3. 11 is a hip joint, 4 is a femur link, 5 is a lower leg link, and 6 is a foot.

The hip joint 11 is rotatably connected to the upper body 2 about the first yaw axis 11a and rotatably about the first roll axis 11b (see FIG. 3). As shown in FIG. 2, the femur link 4 is rotatably connected to the hip joint 11 about the first pitch shaft 11c. The lower leg link 5 is rotatably connected to the femur link 4 about the second pitch shaft 12a. The foot flat portion 6 is rotatably connected to the lower leg link 5 about the third pitch shaft 13b. Each of the hip joint 11, the femur link 4, and the lower leg link 5 has a U-shaped cross section, and includes a pair of side plates facing each other and a connecting portion for connecting the side plates. The foot flat portion 6 has a substantially plate shape.

As shown in FIG. 3, an actuator 15 is arranged at the hip joint 11. The actuator 15 includes a motor and a speed reducer that reduces the rotation of the motor. The rotation of the output shaft 15a of the actuator 15 is transmitted to the foot flat portion 6 via the first link device 21, the second link device 22, and the third link device 23.

The first link device 21 includes a hip joint 11, a first link 31, a driving link 32, and a first articulated link 33. The driving link 32 is rotated about the output shaft 15a of the actuator 15 by the actuator 15 fixed to the hip joint 11. The first link 31 is rotatably connected to the hip joint 11 about the first pitch shaft 11c. The first connecting link 33 is rotatably connected to the driving link 32 via the shaft 41, and is rotatably connected to the first link 31 via the shaft 42.

The first link device 21 is a four-node rotary chain in which these four links 11, 31, 32, and 33 are all rotated and chained by pair-even. The first link device 21 is configured so that the first link 31 can be rotated about the first pitch shaft 11c by rotating the actuator 15.

The first link device 21 may be composed of a parallel motion mechanism or a non-parallel motion mechanism. When the first link device 21 is composed of a parallel motion mechanism, the lengths of two pairs of opposing links are equal. That is, the link length of the hip joint 11 and the link length of the first connecting link 33 are equal, and the link length of the driving link 32 and the link length of the first link 31 are equal. The virtual line 32b of the driving link 32 (the line connecting the output shaft 15a and the shaft 41) and the first virtual line 31a of the first link 31 (the line connecting the first pitch shaft 11c and the shaft 42) are always connected. It is parallel. Further, if the first link device 21 is composed of a non-parallel motion mechanism, the movable range of the first link 31 and thus the palm portion 6 can be expanded.

The second link device 22 includes a first link 31, a femur link 4, a second link 35, and a second connecting link 36. The second link 35 is rotatably connected to the femur link 4 about the second pitch shaft 12a. The second connecting link 36 is rotatably connected to the first link 31 via the shaft 43 and rotatably connected to the second link 35 via the shaft 44.

The second link device 22 is a four-node rotary chain in which these four links 31, 4, 35, and 36 are all rotated and chained by pair-even. The second link device 22 is configured so that if the first link 31 is rotated, the second link 35 can be rotated about the second pitch shaft 12a.

The second link device 22 is also composed of a parallel motion mechanism, and the lengths of two pairs of opposing links are equal. That is, the link length of the thigh link 4 and the link length of the second connecting link 36 are equal, and the link length of the first link 31 and the link length of the second link 35 are equal. The second virtual line 31b of the first link 31 (the line connecting the first pitch shaft 11c and the shaft 43) and the first virtual line 35a of the second link 35 (the line connecting the second pitch shaft 12a and the shaft 44). Is always parallel.

The third link device 23 includes a second link 35, a lower leg link 5, a foot flat portion 6, and a third articulated link 37. The third articulated link 37 is rotatably connected to the second link 35 via the shaft 45, and is rotatably connected to the foot flat portion 6 via the shaft 46.

The third link device 23 is a four-node rotary chain in which these four links 35, 5, 6, and 37 all rotate and are chained by pair-even. The third link device 23 is configured so that the foot flat portion 6 can be rotated about the third pitch shaft 13b by rotating the second link 35.

The third link device 23 is also composed of a parallel motion mechanism, and the lengths of two pairs of opposing links are equal. That is, the link length of the lower leg link 5 and the link length of the third articulated link 37 are equal, and the link length of the second link 35 and the link length of the foot flat portion 6 are equal. The second virtual line 35b of the second link 35 (the line connecting the second pitch shaft 12a and the shaft 45) and the virtual line 6a of the foot flat portion 6 (the line connecting the third pitch shaft 13b and the shaft 46) Are always parallel.

The first link 31 has a triangular shape, and more particularly, a substantially isosceles triangle shape having an apex angle of less than 60 °. The first link 31 is a compound link having three kinematic pairs. The first pitch axis 11c of the first link 31, the axis 42 to which the first articulated link 33 is connected, and the axis 43 to which the second articulated link 36 is connected form the apex of the triangle.

The first articulated link 33 is a crescent-shaped single link having two kinematic pairs. The first articulated link 33 is curved in the axial direction of the first pitch axis 11c so that the range of motion of the first link 31 can be widened.

The second link 35 has a triangular shape, and more specifically, a substantially regular triangular shape. The second link 35 is a compound link having three kinematic pairs. The second pitch shaft 12a of the second link 35, the shaft 44 to which the second articulated link 36 is connected, and the shaft 45 to which the third articulated link 37 is connected form the apex of the triangle.

FIG. 4 shows an operation diagram of the leg portion 3 of the present embodiment. As shown in FIG. 4A, the rotation of the actuator 15 causes the driving link 32 to rotate (see arrow (1)). As the first articulated link 33 moves in the direction of the arrow (2), the first link 31 rotates about the first pitch axis 11c (see arrow (3)). As the second connecting link 36 moves in the direction of the arrow (4), the second link 35 rotates about the second pitch axis 12a (see arrow (5)). As the third articulated link 37 moves in the direction of the arrow (6), the foot flat portion 6 rotates about the third pitch axis 13b (see arrow (7)). FIG. 4B shows a state in which the foot flat portion 6 is rotated, that is, the foot flat portion 6 is extended.

The leg 3 includes an actuator 51 for moving the leg 3 back and forth, an actuator 52 for expanding and contracting the leg 3, and an actuator 53 for rotating the foot flat portion 6 around the second roll shaft 13a. Incorporated (see Figure 2).

The configuration of the walking robot 1 of the present invention has been described above. According to the walking robot 1 of the present embodiment, the following effects are obtained.

Since the actuator 15 is arranged at the hip joint 11, the inertial force when moving the leg 3 at high speed can be reduced. Further, since the rotation of the actuator 15 is transmitted to the foot flat portion 6 via the first link device 21, the second link device 22, and the third link device 23, the first link device 21, the second link device 22, and the second link device 22 are transmitted. The three-link device 23 can be arranged along the hip joint 11, the femur link 4, and the lower leg link 5, and the leg portion 3 can be made thinner.

Since the second link device 22 and the third link device 23 are composed of a parallel motion mechanism, the foot flat portion 6 can be rotated without being affected by the angle of the thigh link 4 and the expansion and contraction of the leg portion 3.

Since the first link 31 is composed of a triangular double link, the first link device 21 can be compactly arranged in the vicinity of the first pitch shaft 11c, and the leg portion 3 can be made compact.

Since the first link 31 and the second link 35 are composed of triangular double links, the range of motion of the foot flat portion 6 can be widened. This will be described in detail below.

5 (a) and 5 (b) show a comparative example in which the first link 31'and the second link 35'are composed of a linear single link. FIG. 5A shows a state in which the leg portion 3'is extended, and FIG. 5B shows a state in which the leg portion 3'is folded. As shown in FIG. 5 (b), when the first link 31'and the second link 35'are composed of a straight single link, when the leg 3 is folded, the first link 31'and the first link 31' The second link 35'becomes on the same straight line, and a singular point (also called a thought point) is generated between the first link 31' and the second link 35'. Therefore, in the state where the leg portion 3'is folded, the range of motion around the third pitch axis 13b'of the foot flat portion 6'exceeds the limit at an early stage.

FIG. 6 shows the present embodiment in which the first link 31 and the second link 35 are composed of triangular double links. 6 (a) and 6 (b) show a state in which the leg 3 is folded at the same angle as in FIG. 5 (b). FIG. 6 (a) shows a state in which the foot flat portion 6 is rotated to the same angle as in FIG. 5 (b), and FIG. 6 (b) shows a state in which the foot flat portion 6 is further rotated.

As shown in FIG. 6B, by configuring the first link 31 and the second link 35 from the triangular double links, the angle until the first link 31 and the second link 35 enter the singular point is increased. This allows the range of motion of the palm portion 6 to be widened.

Further, by curving the first articulated link 33 in a crescent shape, it is possible to avoid interference between the first articulated link 33 and the first pitch shaft 11c as compared with the case where the first articulated link 33 is made linear. The range of motion of the first link 31 can be expanded. This will be described in detail below.

FIG. 7 (a) shows the crescent-shaped first articulated link 33 of the present embodiment, and FIG. 7 (b) shows the linear first articulated link 33'of the comparative example. 7 (a) and 7 (b) show the limit of the movable range of the first articulated links 33, 33', that is, the state in which the first articulated links 33, 33' are interfering with the first pitch shaft 11c.

As shown in FIG. 7A, by bending the first articulated link 33 in a crescent shape, the first articulated link 33 becomes the first pitch shaft 11c in a state where interference with the first pitch shaft 11c is avoided. It can be brought closer (ie, θ1 can be smaller than θ2). Therefore, the range of motion of the first link 31 can be widened. As a result, as shown in FIG. 8, the range of motion θ3 of the foot flat portion 6 can be expanded to approximately 90 °, for example, with the leg portion 3 extended.

According to the present embodiment, the movable range of the palm portion 6 can be widened regardless of the angle of the thigh link 4 with respect to the upper body 2 and regardless of the expansion and contraction of the leg portion 3. Therefore, for example, as shown in FIG. 9 (a), the legs 3 are extended and the hip joint 11 and the upper body 2 are tilted forward, and then the hip joint 11 and the upper body 2 are tilted forward as shown in FIG. 9 (b). Can be upright, or the legs 3 can be bent and stretched as shown in FIG. 9 (c). Further, as shown in FIG. 10 (a), the leg 3 is bent and the hip joint 11 and the upper body 2 are tilted forward to get up, or as shown in FIG. 10 (b), the leg 3 is bent. It is possible to get up from the state where the hip joint 11 and the upper body 2 are upright.

The present invention is not limited to the above embodiment, and can be embodied in other embodiments without changing the gist of the present invention. For example, in the above embodiment, an example in which the present invention is applied to a bipedal walking robot has been described, but it can also be applied to a quadrupedal walking robot.

1 ... walking robot, 4 ... thigh link, 5 ... lower leg link, 6 ... palm, 11 ... hip joint, 11c ... 1st pitch axis, 12a ... 2nd pitch axis, 13b ... 3rd pitch axis, 15 ... actuator, 21 ... 1st link device, 22 ... 2nd link device, 23 ... 3rd link device, 31 ... 1st link, 32 ... prime link, 33 ... 1st connection link, 35 ... 2nd link, 36 ... 2nd connection Link, 37 ... 3rd connecting link, 42 ... Axis to which the 1st connecting link in the 1st link is connected, 43 ... Axis to which the 2nd connecting link in the 1st link is connected, 44 ... 2nd connecting in the 2nd link Axis to which the links are connected, 45 ... Axis to which the third articulated link in the second link is connected

Claims (5)

The thigh link is rotatably connected to the hip joint about the first pitch axis, the lower leg link is rotatably connected to the thigh link about the second pitch axis, and the palm part is rotatably connected to the lower leg link with the third pitch axis. In a walking robot that is rotatably connected around
The actuator placed on the hip joint and
A first link device configured so that the first link can be rotated about the first pitch axis by rotating the actuator.
A second link device configured so that the second link can be rotated about the second pitch axis by rotating the first link.
A walking robot including a third link device configured so that the palm portion can be rotated about the third pitch axis by rotating the second link. The walking robot according to claim 1, wherein each of the second link device and the third link device is a parallel motion mechanism. The first link device has a driving link rotated by the actuator, and a driving link and a first connecting link connected to the first link.
The second link device has a first link and a second connecting link connected to the second link.
Claim 1 or claim 1, wherein the first pitch axis in the first link, the axis to which the first articulated link is connected, and the axis to which the second articulated link is connected form the apex of a triangle. 2. The walking robot according to 2. The third link device has the second link and a third articulated link connected to the foot flat portion.
The third aspect of the present invention is characterized in that the second pitch axis in the second link, the axis to which the second articulated link is connected, and the axis to which the third articulated link is connected form the apex of a triangle. The walking robot described. The walking robot according to claim 3 or 4, wherein the first articulated link is curved in an axial view of the first pitch axis so that the range of motion of the first link can be widened.

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