JP5468973B2 - Legged mobile robot - Google Patents

Description

  The present invention relates to a legged mobile robot.

  2. Description of the Related Art A legged mobile robot that includes a leg having a knee joint that connects an upper leg link and a lower leg link and an ankle joint that connects a lower leg link and a foot, and moves by driving the leg is known.

  For example, in Patent Document 1, a knee joint that connects a thigh link (upper thigh link) and a lower thigh link has a knee Y axis (knee pitch axis), and an output of an electric motor disposed on the upper thigh link is a belt and A legged mobile robot that is transmitted to the knee Y-axis via a speed reducer is disclosed.

  In this legged mobile robot, an electric motor is disposed on the thigh link, and the output of the electric motor is transmitted via a belt to an intermediate shaft disposed coaxially with the knee Y axis. The rotation of the intermediate shaft is transmitted via a belt to a speed reducer disposed on the lower leg link. And the output decelerated by the reduction gear is transmitted to the ankle Y-axis (ankle pitch axis) via the rod mechanism. The rod mechanism is a parallel crank mechanism, and the rotation of the first crank fixed to the outer side of the output shaft of the speed reducer is a second fixed to the outer side of the ankle Y-axis via a parallel link. Transmitted to the crank. As a result, the output of the electric motor is transmitted to the ankle Y-axis via the intermediate shaft, the parallel crank mechanism, etc., and the ankle Y-axis can rotate about the Y-axis (pitch direction).

  Further, another electric motor is disposed on the upper thigh link, and the output of this electric motor is transmitted to another intermediate shaft disposed coaxially with the knee Y axis via the belt. Then, the rotation of the intermediate shaft is transmitted to a passive shaft disposed coaxially with the ankle Y-axis via a belt. A drive bevel gear is fixed to the inner end portion of the end portion of the passive shaft, and this drive bevel gear meshes with a driven bevel gear fixed to the end portion of the ankle X-axis (ankle roll shaft). Thereby, the output of the electric motor is transmitted to the ankle X-axis via the intermediate shaft, the passive shaft, etc., and the ankle X-axis can rotate about the X-axis (roll direction).

JP 2004-298997 A

  In the legged mobile robot disclosed in Patent Document 1, a crank having rods connected to both ends is fixed to the outer side portion of the ankle Y-axis. Furthermore, a passive shaft arranged coaxially with the ankle Y-axis, a drive bevel gear fixed to the inner end of the end of the passive shaft, and a driven bevel gear fixed to the end of the ankle X-axis are provided. Therefore, the ankle part becomes large and the weight increases.

  If the weight of the leg end (foot side) is heavy, a large inertial force is generated in the leg when moving the legged mobile robot, and the actuator that drives each joint needs to have a high output. Arise.

  In view of the above, an object of the present invention is to provide a legged mobile robot capable of making an ankle part compact.

The present invention includes a leg having a knee joint connecting the upper leg link and the lower leg link, and an ankle joint connecting the lower leg link and the foot, and the knee joint and the ankle joint swing in a first direction. A legged mobile robot having a movement axis and moving by driving the leg, a swinging member provided on the lower leg link and swingable about an axis in the first direction ; A front rod connected to the front end of the swinging member, a rear side connected to the foot behind the swinging axis of the ankle joint, and one end connected to the rear end of the swinging member. An ankle joint drive mechanism having a rod and an actuator for driving the front rod is provided.

According to the present invention, the ankle joint drive mechanism can swing the foot around the axis in the first direction with respect to the crus link. And the ankle joint should just be provided with the connection part to which the other end of the rear side rod was connected. Therefore, it is not necessary to fix the crank to the outer side portion of the ankle joint shaft as in Patent Document 1, and the ankle portion can be made compact and lightweight. Accordingly, the inertial force generated in the leg when the legged mobile robot is moved is reduced, and the output of the actuator required for driving the ankle joint can be reduced.

Further, in the present invention, Ru is provided the actuator upwardly in the direction of gravity than the rocking member.

Therefore , an actuator that is a heavy object can be provided at a position away from the foot of the leg, and the inertial force generated in the leg when the legged mobile robot is moved further decreases, and the ankle joint is driven. It is possible to further reduce the output of the actuator required for the above.

Further, in the present invention, the swing center of said swing member, viewed from the side, you positioned forward of the line connecting the pivot axis of the ankle joint and the swing axis of the knee joint.

Therefore , it is possible to suppress the rearward protrusion of the swing member, the possibility that the rear rod and the upper leg link interfere with each other, and a sufficient bending angle of the knee joint can be ensured.

  In the present invention, the ankle joint has a swing axis in a second direction different from the first direction, each leg includes two ankle joint drive mechanisms, and each of the rear rods Are preferably connected to the foot at different positions.

  In this case, it is possible to swing the foot of each leg in the second direction with respect to the lower leg link by independently operating the actuators of the two ankle joint drive mechanisms of each leg. It becomes.

Further, in the present invention, the actuator is provided so as to be rotatable about the axis in the first direction at the same position as the knee joint or in the direction of gravity, and has an end connected to the other end of the front rod. It is preferable to include a rotating plate and a drive source that is provided on the upper thigh link and rotationally drives the rotating plate.

  In this case, the actuator can be configured simply. In addition, since a heavy weight drive source is provided on the upper thigh link away from the foot of the leg, the inertial force generated in the leg when moving the legged mobile robot is reduced, and the ankle joint is driven. It is possible to reduce the output of the drive source necessary for the above.

Further, in the present invention, a first cover fixed to the crus link and covering a rear part of the crus link, a second cover fixed to the foot and covering a rear part of the ankle joint, and a rear part of the foot slidably provided on the shank link with linked, Ru and a third cover covering the rear portion of the rear rod.

Therefore , the third cover always covers the rear portion of the rear rod regardless of the relative movement of the rear rod with respect to the lower leg link accompanying the swing of the foot with respect to the lower leg link. For this reason, even if a gap is generated between the first cover and the second cover, the third cover covers the gap, so that entry of dust, water droplets, or the like can be reliably prevented.

The perspective view which shows schematic structure of the bipedal mobile robot which concerns on embodiment of this invention. The side view which shows the lower part of a leg. The front view which shows the lower part of a leg. FIG. 2 shows a state in which the inclination of the foot is different, (a) shows a state where the foot is raised forward, (b) shows a state where the foot is horizontal, and (c) shows a state where the foot is lowered forward. Show. The side view which shows the lower part of a leg body with a cover. FIG. 5 shows a state where the inclination of the foot is different, (a) shows a state where the foot is raised forward, (b) shows a state where the foot is horizontal, and (c) shows a state where the foot is lowered forward. Show.

  Hereinafter, a bipedal mobile robot 1 (hereinafter simply referred to as a robot 1) according to an embodiment of the present invention will be described using a bipedal mobile robot as an example of a legged mobile robot.

  As shown in FIG. 1, the robot 1 includes a pair of left and right legs 2R and 2L and an upper body 4 connected to the base ends (upper ends) of both legs 2R and 2L, and touches the floor. The upper body 4 is supported above the floor surface by the legs 2R and 2L.

  Both legs 2R and 2L have the same structure, and each has six joints. The six joints are, in order from the upper body 4 side, hip joints 10R and 10L for hip rotation (rotation in the yaw direction relative to the upper body 4), and a hip joint 12R for rotation in the hip roll direction (around the X axis). 12L, hip joints 14R, 14L for rotation in the pitch direction of the crotch (around the Y axis), knee joints 16R, 16L for rotation in the pitch direction of the knee, and ankle joints for rotation in the pitch direction of the ankle 18R, 18L, and ankle joints 20R, 20L for rotation in the roll direction of the ankle portion.

  In the description of the present embodiment, the symbols R and L mean that they correspond to the right leg 2R and the left leg 2L, respectively. The X-axis direction and the Y-axis direction are two axial directions orthogonal to each other on the horizontal plane. The X-axis direction is the front-rear direction (roll axis direction) of the robot 1 and the Y-axis direction is the left-right direction (pitch axis) of the robot 1. Direction). The Z-axis direction is the vertical direction (gravity direction) and corresponds to the vertical direction (yaw axis direction) of the robot 1. The vertical direction means the vertical direction in the direction of gravity.

  The hip joints 10R (L), 12R (L), and 14R (L) of each leg 2R (L) constitute a three-degree-of-freedom hip joint, and the knee joint 16R (L) constitutes a one-degree-of-freedom knee joint, Ankle joints with two degrees of freedom are configured by the ankle joints 18R (L) and 20R (L).

  The hip joints 10R (L), 12R (L), 14R (L) and the knee joint 16R (L) are connected by the upper thigh link 32R (L), and the knee joint 16R (L) and the ankle joint 18R (L). , 20R (L) are connected by a crus link 34R (L). Also, a foot 22R (L) constituting the tip (lower end) of each leg 2R (L) is attached to the lower part of the ankle joints 18R (L), 20R (L) of each leg 2R (L). It is worn. Moreover, the upper end part (base end part) of each leg 2R (L) is connected to the upper body 4 via the hip joints 10R (L), 12R (L), and 14R (L).

  With the above-described configuration of each leg 2R (L), the foot 22R (L) of each leg 2R (L) has six degrees of freedom with respect to the upper body 4. Then, when the robot 1 moves, both legs 2R and 2L are combined and 6 × 2 = 12 joints are respectively driven to appropriate angles, whereby the desired motion of both feet 22R and 22L can be performed. Thereby, the robot 1 can perform a movement that moves in a three-dimensional space, such as a walking action and a running action.

  In addition, although illustration is abbreviate | omitted, in this embodiment, while a left-right paired arm body is attached to the both sides of the upper part of the upper body 4, a head is mounted in the upper end part of the upper body 4. FIG. Each arm body can perform a motion such as swinging the arm body back and forth with respect to the upper body 4 by a plurality of joints (shoulder joint, elbow joint, wrist joint, etc.) provided therein. . However, these arms and heads may be omitted.

  A six-axis force sensor 36R (L) is interposed between the ankle joints 18R (L), 20R (L) and the foot 22R (L) of each leg 2R (L). The six-axis force sensor 36R (L) is a three-axis translational force component of the floor reaction force transmitted from the floor to each leg 2R (L) via the foot 22R (L) and a moment about the three axes. The component is detected, and the detection signal is output to a control unit (not shown).

  Next, the drive mechanism of the ankle joints 18 (L) and 20R (L) of the leg 2R (L) will be described. The legs 2R and 2L are bilaterally symmetric, and here, a drive mechanism for the ankle joints 18R and 20R provided on the leg 2R will be described, but the symbol R will be omitted as appropriate. The other joint drive mechanism may have an arbitrary configuration such as a known configuration proposed by the applicant of the present application in Japanese Patent Laid-Open No. 3-184787.

  2 and 3, the crus link 34 and the foot 22 can swing in the pitch direction with the ankle pitch shaft 42 as the swing center, and in the roll direction with the ankle roll shaft 44 as the swing center. It is connected so that it can swing. Further, the upper thigh link 32 and the lower thigh link 34 are coupled so as to be swingable in the yaw direction with the knee pitch shaft 46 as a relative swing center. In addition, a pitch direction means the 1st direction in this invention, and a roll direction means the 2nd direction different from the 1st direction in this invention.

  The leg 2 includes ankle joint drive mechanisms 50r and 50l for driving the ankle joints 18 and 20. The ankle joint drive mechanism 50 r is provided on the right side of the leg 2, and the ankle joint drive mechanism 50 l is provided on the left side of the leg 2. Thus, the robot 1 includes a total of four ankle joint drive mechanisms 50Rr, 50Rl, 50Lr, and 50Ll.

  In the description of the present embodiment, the symbols r and l mean that they correspond to the right side and the left side of the leg 2R (L), respectively. The ankle joint drive mechanisms 50r and 50l are bilaterally symmetric. Here, the ankle joint drive mechanism 50r will be described, but hereinafter, the symbol r is omitted as appropriate.

  The ankle joint drive mechanism 50 includes a swing member 52, a front rod 54, a rear rod 56, and an actuator 58. The swing member 52, the front rod 54, and the rear rod 56 constitute a Z-type link. .

  The swing member 52 is provided on the crus link 34 so as to be swingable in the pitch direction. Here, the swing member 52 is pivotally supported by the middle part in the vertical direction of the crus link 34 so as to be swingable about the axis 52a in the pitch axis direction. The axis 52 a is located in front of a line segment L connecting the axis of the ankle pitch shaft 42 and the axis of the knee pitch shaft 46 in a side view of the leg 2.

  The front rod 54 has a lower end (one end) 54 a connected to the front end 52 b of the swing member 52. Here, the front rod 54 is connected to the swing member 52 so as to be swingable at least in the pitch direction.

  The rear rod 56 has an upper end (one end) 56 a connected to the rear end 52 c of the swing member 52, and a lower end (other end) 56 b connected to the foot 22 behind the ankle pitch shaft 42. Here, the upper end of the rear rod 56 is connected to the swing member 52 through a spherical bearing (not shown) so as to be swingable in all directions. The lower end of the rear rod 56 is connected to the foot 22 via a spherical bearing 60 so as to be swingable in all directions.

  Specifically, the lower end 56 b of the rear rod 56 is connected to the connecting portion 62 provided at the rear portion of the foot 22 via the spherical bearing 60. An ankle roll shaft 44 is rotatably supported in the roll axis direction at a substantially upper center portion of the foot 22, and an ankle pitch shaft 42 is inserted into the center portion of the ankle roll shaft 44 so as to be rotatable in the pitch axis direction. Yes. And the connection part 62 is spaced apart from the ankle pitch axis | shaft 42 and the ankle roll axis | shaft 44, and the interference with the rear side rod 56 and the crus link 34 is prevented.

  The actuator 58 drives the front rod 54, and is provided above the swing member 52 here. Specifically, the actuator 58 is provided so as to be rotatable in the pitch direction coaxially with the knee pitch shaft 46, and has a rotating plate 64 in which an end portion 64 a is connected to an upper end (the other end) 54 b of the front rod 54, An electric motor 66 that is provided in the link 32 and is a drive source that rotationally drives the rotating plate 64 is provided. The output of the electric motor 66 is transmitted from a reduction mechanism (not shown) via the belt 68, and the rotating plate 64 rotates around the knee pitch shaft 46. The end 64 a is formed in front of the rotation center of the rotating plate 64, that is, the axis of the knee pitch shaft 46. The left and right electric motors 66r and 66l can be independently driven and operate in accordance with an input from the control unit.

  Next, the swinging motion of the ankle joints 18 and 20 will be described.

  The output of the electric motor 66 is transmitted to the rotating plate 64 via the belt 68 and the speed reduction mechanism 70, and the rotating plate 64 rotates. In response to the rotation of the rotating plate 64, the swing member 52 swings through the front rod 54 and the foot 22 swings through the rear rod 56.

  Specifically, when the rotating plate 64 rotates clockwise, the front rod 54 moves upward, whereby the swing member 52 swings clockwise, and the rear rod 56 moves downward to connect The position of the portion 62 moves downward with respect to the intersection point O between the ankle pitch shaft 42 and the ankle roll shaft 44. On the other hand, when the rotating plate 64 rotates counterclockwise, the front rod 54 moves downward, whereby the swing member 52 swings counterclockwise, and the rear rod 56 moves upward, and the connecting portion The position 62 moves upward with respect to the intersection point O between the ankle pitch shaft 42 and the ankle roll shaft 44.

  As a result, when both the left and right rotating plates 64r and 64l rotate clockwise, the connecting portions 62r and 62l move downward with respect to the intersection point O, and as shown in FIG. The foot 22 swings in the pitch direction relative to the crus link 34 so as to incline toward the bottom. On the other hand, when both the left and right rotating plates 64r and 64l rotate counterclockwise, the connecting portions 62r and 62l move upward with respect to the intersection point O, and as shown in FIG. The foot 22 swings in the pitch direction relative to the crus link 34 so as to incline toward the bottom.

  When the right rotating plate 64r rotates clockwise and the left rotating plate 64l rotates counterclockwise, the right connecting portion 62r moves downward with respect to the intersection point O, and the left connecting portion 62l moves upward. The foot 22 swings in the roll direction with respect to the crus link 34 so that the right side is lower than the left side. When the right rotating plate 64r rotates counterclockwise and the left rotating plate 64l rotates clockwise, the right connecting portion 62r moves upward and the left connecting portion 62l moves downward with respect to the intersection point O. The foot 22 swings in the roll direction with respect to the crus link 34 so that the height is higher than the left side.

  Thus, the foot 22 is swung in the pitch direction and the roll direction with respect to the lower leg link 34 by appropriately driving and controlling the left and right electric motors 66r and 66l.

  As described above, in the robot 1 according to the present embodiment, the ankle joint has the ankle roll shaft 44 pivotally supported on the upper portion of the foot 22, the ankle pitch shaft 42 inserted through the ankle roll shaft 44, and the left and right The left and right connecting portions 62r and 62l connected to the rear rods 56r and 56l, respectively, are simply configured. Therefore, compared with the ankle part of the legged mobile robot disclosed in Patent Document 1, the ankle part can be made compact and light. As a result, the inertial force generated in the leg 2 when the robot 1 is moved is reduced, and the rated output of the electric motor 66 that drives the ankle joints 18 and 20 can be reduced.

  In addition, it is assumed that a connecting portion is provided on the foot 22 in front of the intersection point O, and one rod that directly connects the connecting portion and the end portion 64a of the rotating plate 64 is provided. However, in this case, there is a possibility that a sufficient forward angle of the foot 22 cannot be secured. An ankle joint of a human or the like is configured such that the front rising angle is considerably larger than the rear rising angle (front falling angle), and in particular, the front rising angle of the foot 22 is large when kicking a foot. On the other hand, since the robot 1 according to the present embodiment has the connecting portion 62 provided on the foot 22 behind the intersection point O, it is possible to ensure a sufficiently large front rising angle. Note that the rearward rising angle can be limited, but there is no problem as long as it is a human-like movement form.

  In addition, it is assumed that one rod for directly connecting the rear end portion of the rotating plate 64 and the connecting portion 62 is provided. However, in this case, the rod and the upper thigh link 32 interfere with each other, and there is a possibility that a sufficient bending angle of the knee joint 16 cannot be secured. On the other hand, the robot 1 according to the present embodiment has the front rod 54 connected to the front end portion 64a of the rotating plate 64, so there is no possibility that the front rod 54 and the upper leg link 32 interfere with each other, and the knee joint 16 A sufficient bending angle can be secured.

  Further, it is assumed that one rod for directly connecting the end portion 64a of the rotating plate 64 and the connecting portion 62 is provided. However, in this case, the output of the electric motor 66 necessary for swinging the foot 22 increases, and the electric motor 66 having a high rated output is required. On the other hand, since the robot 1 according to the present embodiment transmits the output of the electric motor 66 from the rotating plate 64 to the connecting portion 62 via the swinging member 52, the position and link length of the rotating plate 64, the front rod 54. Further, by appropriately setting the link length of the rear rod 56 and the like, it becomes possible to use the electric motor 66 having a low rated output.

  Further, the axis 52 a of the swinging member 52 is located in front of a line segment L connecting the axis of the ankle pitch shaft 42 and the axis of the knee pitch shaft 46 in a side view of the leg 2. Thereby, it becomes possible to suppress the rearward projection of the rear end portion 52c of the swinging member 52, the possibility of interference between the rear rod 56 and the upper leg link 32 is reduced, and the bending angle of the knee joint 16 is increased. It can be secured sufficiently. Further, by setting the initial angle of the swinging member 52 and the initial angle of the connecting portion 62, the ankle joint drive mechanisms 50r and 50l have high rigidity, and undesired bending does not occur, and a stable driving force is transmitted to the foot 22. It is easy to configure as described above.

  By the way, the leg 2 is composed of precision parts, and it is necessary to prevent adhesion of dust and water droplets, and is covered with a cover. Hereinafter, the cover that covers the lower leg link 34 and the ankle joints 18 and 20 of the leg 2 will be described. The upper thigh link 32, the knee joint 16 and the like may be any conventionally known cover.

  The leg 2 includes a front cover 72 that covers the front part of the lower leg link 34, a rear cover 74 that covers the rear part of the lower leg link 34, an ankle cover 76 that covers at least the rear part of the ankle joints 18 and 20, and a rear part of the rear rod 56. A rear rod cover 78 for covering is provided. Further, the foot 22 is entirely covered with a foot cover 80. The back cover 74 means the first cover in the present invention, the ankle cover 76 means the second cover in the present invention, and the rear rod cover 78 means the third cover in the present invention.

  The front cover 72 is fixed to the crus link 34 by attachment portions 72a and 72b, and is configured to cover the front part of the crus link 34 without interfering with the front rod 54.

  The rear cover 74 is fixed to the crus link 34 by a mounting portion 74a, and is configured to cover the rear part of the crus link 34 without interfering with a cover (not shown) of the rear rod 56 and the crus link 32. . The rear cover 74 is connected to the front cover 72 at the side thereof.

  The ankle cover 76 is fixed to the foot 22 with a mounting portion (not shown), and is configured to cover the periphery of the ankle joints 18 and 20 including the rear of the connecting portion 62. Since the ankle cover 76 is fixed to the foot 22, the ankle cover 76 always covers the rear of the connecting portion 62 regardless of the swinging of the foot 22. Note that the front portion of the ankle cover 76 is configured as a sliding shutter, although not shown in detail, so that there is no gap with the lower end of the front cover 72 regardless of the swing of the foot 22.

  The rear rod cover 78 is connected to the rear portion of the foot 22 and is slid by being guided by a guide mechanism 82 provided on the crus link 34 to cover the rear portion of the rear rod 56. .

  Specifically, one end of an L-shaped connecting rod 84 is rotatably connected to the connecting portion 78a formed on the inner surface of the rear rod cover 78 in the substantially vertical direction in the up-down direction. The other end is connected to a protrusion 86 formed on the rear portion of the foot 22 in the vicinity of the connecting portion 62 so as to be rotatable in the pitch direction. The guide mechanism 82 is fixed to a substantially intermediate portion in the vertical direction of the crus link 34 with a bolt, and has a guide member 88 formed with an elongated hole 88a extending obliquely downward and slid into the elongated hole 88a. The pin 90 is provided so as to be provided and provided at the tip of an extending portion 78 b extending above the rear rod cover 78.

  As a result, the rear rod cover 78 is positioned in the middle of the rear cover 74 and the ankle cover 76 in the front-rear direction, and interferes with the rear cover 74 and the ankle cover 76 regardless of the swing of the foot 22 with respect to the crus link 34. It is configured not to.

  The rear rod cover 78 moves with the movement of the rear rod 56, and the change in the distance between the connecting portion 78a of the rear rod cover 78 and the lower end 56b of the rear rod 56, particularly the change in the distance in the vertical direction is small. Become. For this reason, the rear rod cover 78 always covers the lower rear portion of the rear rod 56 regardless of the relative movement of the rear rod 56 with respect to the crus link 34, and the foot 22 is inclined forward and rearward. Even if a gap is generated between the cover 74 and the ankle cover 76, the rear rod cover 78 covers the gap.

  As described above, since the robot 1 according to this embodiment includes the rear rod cover 78, as shown in FIG. 6 (a), the foot 22 is greatly inclined forwardly. Also, the lower rear of the rear rod 56 can be covered by the rear rod cover 78. Regardless of the swing of the foot 22, the gap generated between the rear rod cover 78, the rear cover 74, and the ankle cover 76 is always small.

  In the case where the rear rod 56 is not provided, in order to always cover the lower rear portion of the rear rod 56 with a cover, the rear cover and the ankle cover are enlarged, and it is difficult to make the ankle portion slim. In addition, a large gap is inevitably formed between the rear cover and the ankle cover, and there is a possibility that dust, water droplets, or the like may enter from the gap.

  In addition, although embodiment of this invention was described above, this invention is not limited to this. For example, in the embodiment, the actuator 58 is rotationally driven by the electric motor 66 and the end portion 64a includes the rotating plate 64 connected to the upper end 54b of the front rod 54. However, the present invention is not limited to this. For example, the front rod 54 may be linearly driven using a ball screw mechanism.

  Furthermore, as long as it has a knee joint 16R (L) and an ankle joint 18R (L) that rotate the knee and ankle in the same direction (pitch direction in the embodiment), the configuration of each joint and the arrangement of the joints are as follows. It is not limited to the embodiment. For example, the ankle joint 20R (L) that rotates the ankle portion in the roll direction may not be provided. In this case, one ankle joint drive mechanism may be provided for each leg 2R (L).

  Furthermore, as long as the ankle joints 18R (L) and 20R (L) have different ankle rotation directions, the rotation directions are not limited to the embodiment. For example, the rotation directions of the ankle portions of the ankle joints 18R (L) and 20R (L) may not be orthogonal to each other.

  Furthermore, it is not limited to a bipedal mobile robot. For example, a 4-legged mobile robot or a 6-legged mobile robot imitating a beast or an insect may be used.

  DESCRIPTION OF SYMBOLS 1 ... Biped mobile robot (leg type mobile robot), 2R, 2L ... Leg, 16R, 16L ... Knee joint, 18R, 18L, 20R, 20L ... Ankle joint, 22R, 22L ... Foot, 34R, 34L ... Lower leg Link, 42 ... Ankle pitch axis, 44 ... Ankle roll axis, 46 ... Knee pitch axis, 50 ... Ankle joint drive mechanism, 52 ... Swing member, 52a ... Axis of swing member, 52b ... Front end of swing member, 52c ... rear end of swing member, 54 ... front rod, 54a ... lower end (one end) of front rod, 54b ... upper end (other end) of front rod, 56 ... rear rod, 56a ... upper end (one end) of rear rod 56b ... lower end (other end) of the rear rod, 58 ... actuator, 62 ... coupling part, 64 ... rotating plate, 66 ... electric motor (drive source), 74 ... rear cover (first cover), 76 ... Neck cover (second cover), 78 ... rear rod cover (third cover), 82 ... guide mechanism.

Claims (3)

A leg having a knee joint connecting the upper leg link and the lower leg link and an ankle joint connecting the lower leg link and the foot, the knee joint and the ankle joint having a swing axis in a first direction; And a legged mobile robot that moves by driving the leg,
A swing member provided on the lower leg link and swingable about an axis in the first direction;
A front rod having one end connected to the front end of the swing member;
A rear rod having one end connected to the rear end of the swing member and the other end connected to the foot behind the swing axis of the ankle joint;
Have a ankle joint drive mechanism having an actuator for driving the front rod,
The actuator is provided above the swing member in the direction of gravity,
The swing center of the swing member is located in front of a line connecting the swing axis of the knee joint and the swing axis of the ankle joint in a side view,
A first cover fixed to the lower leg link and covering a rear portion of the lower leg link;
A second cover fixed to the foot and covering a rear portion of the ankle joint;
A legged mobile robot comprising a third cover that is coupled to a rear portion of the foot and is slidably provided on the lower leg link and covers a rear portion of the rear rod . The ankle joint has a swing axis in a second direction different from the first direction;
2. The legged mobile robot according to claim 1 , wherein each leg includes two ankle joint driving mechanisms, and each of the rear rods is connected to the foot at a different position. The actuator is
A rotary plate provided at the same position as the knee joint or in a gravity direction so as to be rotatable about the axis in the first direction , and having an end connected to the other end of the front rod;
The legged mobile robot according to claim 1 , further comprising a drive source that is provided on the upper thigh link and that rotationally drives the rotating plate.

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