JP2013248698A - Lower limb structure for legged robot, and legged robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a legged robot by which a mechanism using parallel linkage can be achieved, and as a result, an actuator load can be reduced even if legs are connected to a hip joint body via a joint having two degrees in freedom.SOLUTION: A hip joint 22 is provided which can rotate around a rolling axis 22a1 of a hip joint body 18, and can rotate around a pitching axis 22a2 of a thigh member 12a. One end of an auxiliary link 31 which configures a parallel linkage mechanism 41 is connected to the hip joint 22 so as to be capable of rotating around the pitching axis.

Description

  The present invention relates to a lower limb structure of a legged robot that has a plurality of legs and walks while swinging each leg, and a legged robot.

  The legged robot has a plurality of legs and walks while swinging each leg. A legged robot that walks while balancing on two legs like a human is called a biped robot. A legged robot that walks on four legs like an animal is called a quadruped walking robot. The number of legs is typically two or four, but may be any number as long as there are a plurality of legs.

  Each leg part is configured by sequentially connecting links corresponding to the thigh part, the lower leg part, and the foot part from the trunk part of the robot through the hip joint, the knee joint, and the ankle joint. Links corresponding to the thigh, crus, and foot are connected to each joint so as to be rotatable about a pitch axis extending to the side of the legged robot. Each joint is provided with a motor (actuator) that rotates the link. When the motor outputs an appropriate driving force and controls the rotation angle of the link, the legged robot can swing the leg portion back and forth with respect to the trunk portion. Here, the hip joint means a joint that connects the torso and the leg, and the joint that connects the torso and the front leg of the quadruped walking robot is also included in the hip joint. The motor is a device that converts energy such as electricity and gasoline into mechanical movement, and is typically an electric motor or an engine.

  However, if motors are arranged at all joints, there is a problem that not only the structure of the legs is complicated, but also the load on the motor is increased. In order to solve this problem, Patent Literature 1 discloses that the hip joint body and the knee joint body are coupled via a pair of parallel links, and the knee joint body and the ankle joint body are coupled via a pair of parallel links. A legged robot has been proposed. According to the legged robot using the parallel link, there is an advantage that the load on the motor can be reduced.

JP 2011-125966 A

  However, there are cases where the thigh is connected to the hip joint body via a two-degree-of-freedom joint of a roll axis and a pitch axis in order to bring the leg of the legged robot closer to the leg of a human or animal. In this case, if the hip joint body and the knee joint body are connected using a pair of parallel links as in a conventional legged robot using parallel links, there is a problem that the mechanism is not established. This is because when the hip joint body and the knee joint body are connected using a pair of parallel links, the thigh is connected to the hip joint body so as to be rotatable around the roll axis and the pitch axis. This is because the thigh cannot rotate around the roll axis with respect to the joint body.

  A similar problem occurs when the lower leg is connected to the ankle joint body via a two-degree-of-freedom joint of the roll axis and the pitch axis in order to bring the leg of the legged robot closer to the leg of a human or animal. .

  Therefore, the present invention can establish a mechanism using a parallel link even when the leg is connected to the hip joint body or the ankle joint body via a joint with two degrees of freedom, thereby reducing the load on the actuator. The object is to provide a legged robot.

  In order to solve the above-described problems, an embodiment of the present invention includes a hip joint body, a thigh, and a roll axis that is rotatable with respect to the hip joint body and a pitch axis with respect to the thigh. A hip joint that is rotatable around the knee, a knee joint body that is rotatably coupled to the thigh around a pitch axis, and the hip joint is spanned between the thigh and the hip joint body. An actuator for rotating the thigh about the roll axis and the pitch axis of the hip joint with respect to the main body, one end of which is connected to the hip joint so as to be rotatable about the pitch axis; The leg structure of a legged robot comprising: an auxiliary link having an end rotatably connected to the knee joint main body about a pitch axis.

  In another aspect of the present invention, the ankle joint body, the lower leg, and the ankle joint body can be rotated about a roll axis, and the lower leg can be rotated about a pitch axis. An ankle joint joint, a knee joint main body rotatably connected to the lower leg part around a pitch axis, and spanned between the lower leg part and the ankle joint main body, On the other hand, an actuator for rotating the ankle joint body about the roll axis and the pitch axis of the ankle joint joint, one end portion being connected to the ankle joint joint for rotation about the pitch axis, The leg structure of a legged robot comprising: an auxiliary link having an end rotatably connected to the knee joint main body about a pitch axis.

  According to one aspect of the present invention, one end of the auxiliary link is pitched to the hip joint that can rotate about the roll axis with respect to the hip joint body and can rotate about the pitch axis with respect to the thigh. Since the rotation about the shaft is rotatably connected, the joint of the thigh with 2 degrees of freedom with respect to the hip joint body and the swinging of the thigh using the parallel link can be achieved. Therefore, the load on the actuator can be reduced.

  According to another aspect of the present invention, one end of the auxiliary link is connected to the ankle joint joint that can rotate about the roll axis with respect to the ankle joint body and that can rotate about the pitch axis with respect to the crus. Since the portions are connected so as to be rotatable around the pitch axis, the joint of the ankle joint main body with respect to the crus and the swinging of the crus using a parallel link mechanism can be achieved. Therefore, the load on the actuator can be reduced.

The perspective view which shows the whole structure of the legged robot of one Embodiment of this invention. Front view of legged robot of this embodiment Left side view of legged robot of this embodiment The figure which shows the mode of a leg part when the legged robot of this embodiment performs bending and extending movement (FIG. 4 (a) shows the state which extended the knee joint and extended the leg part, FIG.4 (b) shows a knee. (Bends the joint to bend the leg and swings the leg around the roll axis) Three-side view of the leg portion of the legged robot of the present embodiment in an extended state (FIG. 5 (a) is a front view, FIG. 5 (b) is a left side view, and FIG. 5 (c) is a rear view). FIG. 6A is a front view, FIG. 6B is a left side view, and FIG. 6B is a front view of a leg portion of the legged robot of the present embodiment in a state where it is bent and swung around a roll axis. 6 (c) shows a rear view) FIG. 7A is a rear view, and FIG. 7B is a right side view of the leg portion of the legged robot of the present embodiment in a state where it is bent and swung around the roll axis. )

  Hereinafter, a legged robot according to an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view showing the overall configuration of the legged robot of this embodiment, FIG. 2 is a front view, and FIG. 3 is a side view. In the following description, the advancing direction of the legged robot is the x-axis direction, the left-right direction as viewed from the legged robot is the y-axis direction, the up-and-down direction of the legged robot is the z-axis direction, the x-axis is the roll axis, and the y-axis is the pitch The axis and the z axis are the yaw axes. In the following description, the left and right are the left and right when viewed from the legged robot side shown in FIGS. 1 to 3, and the front and rear are the front and rear when viewed from the legged robot side.

  As shown in FIG. 1, the legged robot 10 includes two legs 12 installed below the trunk 11, two arms 13 installed on both the left and right sides of the trunk 11, It is composed of a single head (not shown) installed above the torso 11 and enables operation close to that of a human.

  The two arm portions 13 are connected to the trunk portion 11 via a shoulder joint 16 and can rotate around the yaw axis and the roll axis with respect to the trunk portion 11. Each arm portion 13 includes an upper arm portion 13b closer to the shoulder, and a lower arm portion 13c closer to the hand portion 13a, with the elbow joint 17 as a boundary. The lower arm portion 13c can rotate around the yaw axis and the pitch axis with respect to the upper arm portion 13b.

  The leg portion 12 is connected to the pelvis of the trunk portion 11 through the hip joint 8 so as to be swingable about the roll axis and the pitch axis. The legged robot 10 swings the two legs 12 alternately around the pitch axis and the roll axis, and walks in a balanced manner with two legs like a human.

  The leg 12 includes a hip joint 8, a thigh 12 a, a knee joint body 19, a crus 12 b, an ankle joint 9, and a foot 21, which are coupled to the trunk 11 in order from the top. The hip joint 8 includes a hip joint body 18 coupled to the body 11, a hip joint 22 (see also FIG. 2) that connects the hip joint body 18 and the thigh 12 a so as to be rotatable around the pitch axis and the roll axis. Is provided. The knee joint body 19 is connected to the thigh 12a so as to be rotatable about the pitch axis. The crus 12b is connected to the knee joint body 19 so as to be rotatable about the pitch axis. The ankle joint 9 includes an ankle joint body 20 coupled to the foot 21, and an ankle joint joint 24 that connects the ankle joint body 20 and the crus 12 b so as to be rotatable about a roll axis and a pitch axis (see FIG. 2). See also). The foot 21 is fixed to the ankle joint body 20. The foot 21 is landed on the walking road surface.

  The legged robot 10 is a robot configured to be remotely operable. When the operator operates an operation manipulator (not shown) located at a remote position, the legged robot 10 performs an operation according to the movement of the operation manipulator. It can be executed.

  Next, the structure of the leg portion 12 of the legged robot 10 of this embodiment will be described in detail with reference to FIGS. 4 to 6. FIG. 4 shows a state in which the leg 12 performs a bending / extending motion. 4A shows a state in which the knee joint body 19 is extended and the leg portion 12 is extended. FIG. 4B shows a state in which the knee joint body 19 is bent to bend the leg portion 12 and the leg portion 12 is rolled. A state of swinging around the shaft is shown. FIG. 5 shows a trihedral view of the extended leg 12 and FIG. 6 shows a trihedral view of the leg 12 bent and swung about the roll axis.

  As shown in FIG. 4, the leg portion 12 includes a hip joint body 18, a thigh 12 a, a knee joint body 19, a crus 12 b, an ankle joint body 20, and a foot 21. The hip joint body 18 is formed by bending a plate, and has a quadrangular coupling portion 18a coupled to the trunk portion 11, a pair of joint coupling portions 18b folded from a pair of opposing sides of the coupling portion 18a, and a coupling portion 18a. And a pair of actuator connecting portions 18c bent from a pair of opposite sides.

  As shown in FIG. 5, a thigh 12 a is connected to the hip joint body 18 via a passive hip joint 22 so as to be rotatable about a roll axis and a pitch axis. The hip joint 22 has a main body 22a that can rotate about the roll axis with respect to the hip main body 18 and that can rotate about the pitch axis with respect to the thigh 12a. The main body 22a is formed in a cross shape so as to constitute a pitch axis and a roll axis that are orthogonal to each other. Both end portions of the roll shaft 22a1 of the main body portion 22a are rotatably connected to the pair of joint connection portions 18b of the hip joint body 18 via bearings. Both end portions of the pitch shaft 22a2 of the main body portion 22a are rotatably connected to the pair of joint connecting portions 12a1 of the thigh portion 12a via bearings. An arm 22b is coupled to the main body portion 22a. An auxiliary link 31 (see FIG. 5C), which will be described later, is connected to the arm 22b so as to be rotatable around the pitch axis. The arm 22b and the auxiliary link 31 will be described later.

  As shown in FIG. 4, the thigh 12a has a pair of left and right side wall plates 12a2 and a connecting plate 12a3 that connects the pair of left and right side wall plates on the back side of the thigh 12a. A pair of joint connecting portions 12a1 connected to the hip joint 22 is formed at the upper end of the thigh 12a.

  A pair of left and right actuators 25 are bridged between the upper portion of the thigh 12 a and the hip joint body 18. Each actuator 25 includes a motor 26 coupled to the side wall plate 12a2 of the thigh 12a, a servo horn 27 coupled to the output shaft of the motor 26, and between the servo horn 27 and the actuator connecting portion 18c of the hip joint body 18. And a connecting link 28 for connecting the two. The lower end portion of the connection link 28 is connected to the servo horn 27 via a spherical bearing, and the upper end portion of the connection link 28 is connected to the actuator connection portion 18c of the hip joint body 18 via a spherical bearing.

  When the motors 26 of the pair of actuators 25 are rotated in the same direction, the thigh 12a rotates about the pitch axis 22a2 with respect to the hip joint body 18. On the other hand, when the motors 26 of the pair of actuators 25 are rotated in different directions, the thigh 12a rotates about the roll shaft 22a1 with respect to the hip joint body 18. By controlling the rotation angle of each actuator 25, the thigh 12a can be rotated around the pitch axis 22a2 and the roll axis 22a1 with respect to the hip joint body 18.

  As in this embodiment, a passive hip joint 22 having two degrees of freedom is interposed between the hip joint body 18 and the thigh 12a, and two actuators 25 are provided between the hip joint body 18 and the thigh 12a. By bridging, it is possible to generate several times more force than when two motors functioning as active joints are provided on the pitch axis and roll axis of the hip joint body. Since the actuator 25 for obtaining a necessary force can be reduced in size, the leg portion 12 can be reduced in size.

  Further, when the legged robot is walked on two legs, torque is required to rotate the leg portion 12 around the roll axis with respect to the hip joint body 18, and the leg portion 12 is moved to the pitch axis with respect to the hip joint body 18. Speed is required to rotate around. By bridging the two actuators 25 between the hip joint body 18 and the thigh 12a, it becomes easy to meet the two requirements of the torque around the roll axis and the speed around the pitch axis.

  A knee joint body 19 is attached to the lower end of the thigh 12a so as to be rotatable around the pitch axis 19a. The knee joint body 19 is formed by bending the plate into a U-shaped cross section. A motor 29 for driving the knee joint body 19 is coupled to the lower end of the side wall plate 12a2 of the thigh 12a. The output shaft of the motor 29 is fixed to the knee joint body 19. The motor 29 functions as an active joint, and the motor 29 constitutes the pitch axis 19 a of the knee joint body 19. By rotating the motor 29, the knee joint body 19 rotates around the pitch axis 19a with respect to the thigh 12a. In the state where the leg 12 is upright, the thigh 12 a is in contact with the knee joint body 19.

  A crus 12b is attached to the knee joint body 19 so as to be rotatable around the pitch axis 19b. The crus part 12b has a pair of left and right side wall plates 12b2 and a connecting plate 12b3 that connects the pair of left and right side wall plates 12b2 on the rear side of the crus part 12b. A motor 30 is coupled to the upper end of the side wall plate 12b2 of the crus 12b. The output shaft of the motor 30 is fixed to the knee joint body 19. The motor 30 functions as an active joint, and the motor 30 constitutes the pitch axis 19 b of the knee joint body 19. By rotating the motor 30, the crus part 12 b rotates around the pitch axis 19 b with respect to the knee joint body 19. In the state where the leg portion 12 is upright, the crus portion 12 b is in contact with the knee joint body 19.

  An ankle joint body 20 is connected to the lower leg 12b through an ankle joint joint 24 so as to be rotatable about a roll axis and a pitch axis. A pair of joint connecting portions 12b1 connected to the ankle joint joint 24 is formed at the lower end of the crus 12b. The ankle joint body 20 is formed by bending a plate, and is coupled to a square coupling portion 20a coupled to the foot portion 21 and a pair of joint coupling portions 20b folded from a pair of opposing sides of the coupling portion 20a. A pair of actuator connecting portions 20c bent from a pair of opposite sides of the portion 20a.

  As shown in FIG. 5, the ankle joint joint 24 includes a main body portion 24a that can rotate about the roll axis with respect to the ankle joint main body 20 and that can rotate about the pitch axis with respect to the crus portion 12b. Have. The main body 24a is formed in a cross shape so as to constitute a roll shaft 24a1 and a pitch shaft 24a2 that are orthogonal to each other. Both end portions of the roll shaft 24a1 of the main body portion 24a are rotatably connected to a pair of joint connecting portions 20b of the ankle joint main body 20 via bearings, and both end portions of the pitch shaft 24a2 of the main body portion 24a are a pair of the lower leg portions 12b. The joint connecting portion 12b1 is rotatably connected via a bearing. An arm 24b is coupled to the main body 24a. An auxiliary link 32 (see FIG. 5C), which will be described later, is coupled to the arm 24b so as to be rotatable around the pitch axis. The arm 24b and the auxiliary link 32 will be described later.

  As shown in FIG. 4, a pair of left and right actuators 36 are bridged between the lower part of the crus 12 b and the ankle joint body 20. Each actuator 36 includes a motor 33 coupled to the side wall plate 12 b 2 of the crus 12 b, a servo horn 34 coupled to the output shaft of the motor 33, and the servo horn 34 and the actuator connecting portion 20 c of the ankle joint body 20. A connection link 35 connecting the two. The upper end portion of the connection link 35 is connected to the servo horn 34 via a spherical bearing, and the lower end portion of the connection link 35 is connected to the actuator connection portion 20c of the ankle joint body 20 via a spherical bearing.

  When the motor 33 of the pair of actuators 36 is rotated in the same direction, the ankle joint body 20 rotates about the pitch axis 24a2 with respect to the crus 12b. On the other hand, when the motors 33 of the pair of actuators 36 are rotated in different directions, the ankle joint body 20 rotates around the roll shaft 24a1 with respect to the crus 12b. By controlling the rotation angle of each actuator 36, the ankle joint body 20 can be rotated around the pitch shaft 22a2 and the roll shaft 22a1 with respect to the crus 12b.

  Each motor 26, 29, 30, 33 is controlled by a driver adjacent to each motor 26, 29, 30, 33. The driver uses a power converter such as a PWM (pulse width modulation) inverter that supplies power to the motor, a sensor that detects the speed and position of the motor output shaft, a command from the operation manipulator, and information from the sensor. A controller for controlling is provided. The drivers communicate with each other and can be synchronized without a separate control box.

  Next, the parallel link mechanism which is one of the features of this embodiment will be described. As shown in FIG.5 (b), the leg part 12 incorporates two parallel link mechanisms 41 and 42 up and down. The upper parallel link mechanism 41 includes four links a1, b1, c1, and d1 forming a parallelogram. The lengths of the opposing links are equal, and there is a relationship of a1 = c1, b1 = d1. The link a1 includes the arm 22b of the hip joint 22, the link c1 includes the knee joint body 19, the link b1 includes the thigh 12a, and the link d1 includes the auxiliary link 31 on the rear side of the thigh 12a. When the thigh 12 a is swung around the pitch axis, the upper parallel link mechanism 41 always moves the knee joint body 19 in parallel with the hip joint 22.

  The lower parallel link mechanism 42 includes four links a2, b2, c2, and d2 forming a parallelogram. The lengths of the opposing links are equal, and there is a relationship of a2 = c2 and b2 = d2. The link a2 is constituted by the knee joint body 19, the link c2 is constituted by the arm 24b of the ankle joint joint 24, the link b2 is constituted by the crus part 12b, and the link d2 is constituted by the auxiliary link 32 on the rear side of the crus part 12b. When the lower leg 12b is swung around the pitch axis, the lower parallel link mechanism 42 always moves the ankle joint joint 24 in parallel with the knee joint body 19.

  By providing the two parallel link mechanisms 41 and 42 on the upper and lower sides, it is guaranteed that the ankle joint joint 24 is moved in parallel with respect to the hip joint 22. For this reason, not only the leg portion 12 can be easily controlled, but also when the legged robot is about to fall down, the parallel link mechanisms 41 and 42 are prevented from falling down, so the actuator 36 below the lower leg portion 12b. It is no longer necessary to apply a large load to prevent falling.

  Next, the structure of the upper parallel link mechanism 41 will be described in detail with reference to FIG. FIG. 7 shows a detailed view of the leg 12 in a state in which the knee joint body 19 is bent to bend the leg 12 and the leg 12 is swung around the roll axis. FIG. 7A shows a rear view of the leg 12, and FIG. 7B shows a side view of the leg 12.

  An arm 22 b is coupled to the cross-shaped main body portion 22 a of the hip joint 22. The lower end of the arm 22b is bifurcated, and the upper end of the auxiliary link 31 is rotatably connected to the bifurcated portion via a spherical bearing. The axis of rotation about the pitch axis of the auxiliary link 31 with respect to the arm 22b is parallel to the pitch axis 22a2 of the main body 22a of the hip joint 22, and is separated from the pitch axis 22a2 by a predetermined distance (the length of the link a1). The lower end portion of the auxiliary link 31 is rotatably connected to the support shaft 43 of the knee joint body 19 via a spherical bearing. The axis of rotation about the pitch axis of the auxiliary link 31 relative to the knee joint body 19 is parallel to the pitch axis 19a relative to the thigh 12a of the knee joint body 19 and is a predetermined distance from the pitch axis 19a (the length of the link c1). is seperated. The length from the upper end to the lower end of the auxiliary link 31 is equal to the length of the link d1, and is equal to the length of the link b1 from the pitch axis 22a2 to the pitch axis 19a of the thigh 12a.

  With reference to FIGS. 5B and 5C, the structure of the lower parallel link mechanism 42 will be described in detail. An arm 24 b is coupled to the cross-shaped main body portion 24 a of the ankle joint joint 24. The upper end portion of the arm 24b is divided into two portions, and the lower end portion of the auxiliary link 32 is rotatably connected to the divided portion through a spherical bearing. The axis of rotation about the pitch axis of the auxiliary link 32 with respect to the arm 24b is parallel to the pitch axis 24a2 of the main body 24a and is separated from the pitch axis 24a2 by a predetermined distance (the length of the link c2). The upper end of the auxiliary link 32 is rotatably connected to the support shaft 43 of the knee joint body 19 via a spherical bearing. The axis of rotation about the pitch axis of the auxiliary link 32 relative to the knee joint body 19 is parallel to the pitch axis 19b relative to the crus 12b of the knee joint body 19 and is a predetermined distance (the length of the link a2) from the pitch axis 19b. Just away. The length from the lower end portion to the upper end portion of the auxiliary link 32 is equal to the length of the link d2, and is equal to the length of the link b2 from the pitch axis 19b of the crus portion 12b to the pitch axis 24a2.

  As shown in FIG. 7A, in this embodiment, since the lower end portion of the auxiliary link 31 and the upper end portion of the auxiliary link 32 are connected to the support shaft 43 of the knee joint body 19, the auxiliary link 31. , 32 need to be shifted in the axial direction of the support shaft 43 and connected to the support shaft 43. For this reason, since the upper auxiliary link 31 is inclined with respect to the thigh 12a and the lower auxiliary link 32 is inclined with respect to the lower thigh 12b, the auxiliary link 31 and the auxiliary link 32 are supported via spherical bearings. The shaft 43 and the arms 22b and 24b are connected. When the auxiliary links 31 and 32 are parallel to the thigh 12a and the crus 12b, the auxiliary links 31 and 32 can be connected to the support shaft 43 and the arms 22b and 24b through bearings with one degree of freedom. it can.

  The structure of the legged robot of this embodiment has been described above. The legged robot according to this embodiment has the following effects.

  The hip joint 22 is provided with a main body portion 22a that can rotate about the roll axis with respect to the hip joint body 18 and that can rotate about the pitch axis with respect to the thigh 12a, and an arm 22b is attached to the main body portion 22a. Since the upper end portion of the auxiliary link 31 is rotatably connected to the arm 22b, the thigh portion 12a swings using the two-degree-of-freedom joint of the thigh portion 12a with respect to the hip joint body 18 and the parallel link mechanism 41. Can be made compatible. Therefore, the load on the actuators 25 and 29 can be reduced.

  Further, the ankle joint joint 24 is provided with a main body portion 24a that can rotate about the roll axis with respect to the ankle joint body 20 and that can rotate about the pitch axis with respect to the crus portion 12b. Since the arm 24b is coupled to the arm 24b and the lower end portion of the auxiliary link 32 is rotatably connected to the arm 24b, the ankle joint body 20 has a two-degree-of-freedom joint with respect to the crus 12b and the crus using the parallel link mechanism 42. The swinging of the part 12b can be made compatible. Therefore, the load on the actuators 30 and 36 can be reduced.

  As described above, by providing the two upper and lower parallel link mechanisms 41, 42, the load on the actuators 25, 29, 30, 36 can be reduced, the actuators 25, 29, 30, 36 can be downsized, and the legs 12 can be downsized. Can be realized.

  By providing the auxiliary link 31, the operations of the two actuators 25 at the upper part of the thigh 12a and the one actuator 29 at the lower part of the thigh 12a can be coordinated. If the auxiliary link 31 is not provided, the torque of the actuators 25 and 29 cannot be used up between the upper part and the lower part of the thigh 12a, so that walking ability is reduced. Also by providing the auxiliary link 32, the operations of the one actuator 30 at the upper part of the crus 12b and the two actuators 36 at the lower part of the crus 12b can be coordinated.

  In addition, this invention is not limited to the said embodiment, It can change into various embodiment in the range which does not change the summary of this invention.

  For example, in the above-described embodiment, the hip joint includes the cross-shaped main body that forms the roll axis and the pitch axis. However, the roll axis is provided in the hip joint body, the pitch axis is provided in the thigh, and the hip joint is connected to the hip joint. Holes that fit into the roll axis of the main body and the pitch axis of the thigh can also be formed. The pitch axis and roll axis of the hip joint need not be orthogonal as long as they are perpendicular. The same applies to the ankle joint joint.

  In the above-described embodiment, a rotary motor is used as the actuator spanned between the hip joint body and the thigh. However, a direct-acting actuator that expands and contracts its entire length can also be used. The same applies to the actuator that spans between the ankle joint body and the lower leg.

  In the above embodiment, a motor is used as an active joint in the knee joint body, but a passive joint made of a bearing can be provided without providing a motor in the knee joint body.

  In the above-described embodiment, the lower leg part is connected to the knee joint body so as to be rotatable around the pitch axis, but the knee joint body and the lower leg part can also be configured from an integral frame. Moreover, in the said embodiment, although the hip joint main body was couple | bonded with the trunk | drum, a hip joint main body and a trunk | drum can also be comprised from an integral flame | frame. Furthermore, in the said embodiment, although the ankle joint main body was couple | bonded with the foot part, an ankle joint main body and a foot part can also be comprised from an integral flame | frame.

  In the above embodiment, a motor is used as a drive source for swinging the leg portion, but various other devices such as a pneumatic or hydraulic cylinder, a linear motor, and an artificial muscle actuator can be used as the drive source. Can do.

DESCRIPTION OF SYMBOLS 10 ... Leg type robot, 12 ... Leg part, 12a ... Thigh part, 12b ... Lower leg part, 18 ... Hip joint body, 19 ... Knee joint body, 20 ... Ankle joint body, 22 ... Hip joint body, 22a ... Body part, 22b ... arm, 24 ... ankle joint, 24a ... main body, 24b ... arm, 25 ... actuator, 31 ... auxiliary link, 32 ... auxiliary link, 36 ... actuator

Claims (5)

The hip body,
The thigh,
A hip joint that is rotatable about a roll axis relative to the hip joint body and is rotatable about a pitch axis relative to the thigh;
A knee joint body coupled to the thigh for rotation about a pitch axis;
An actuator that spans between the thigh and the hip joint body, and rotates the thigh around the roll axis and the pitch axis of the hip joint body with respect to the hip joint body;
And an auxiliary link having one end connected to the hip joint so as to be rotatable about the pitch axis and the other end connected to the knee joint body so as to be rotatable about the pitch axis. Lower limb structure. The hip joint has a cross-shaped main body part that constitutes the roll axis and the pitch axis, and an arm coupled to the main body part,
The leg structure of the legged robot according to claim 1, wherein the one end of the auxiliary link is rotatably connected to the arm. An ankle joint body,
The lower leg,
An ankle joint joint that is rotatable about a roll axis with respect to the ankle joint body and rotatable about a pitch axis with respect to the crus;
A knee joint body coupled to the lower leg so as to be rotatable about a pitch axis;
An actuator that is spanned between the crus and the ankle joint body, and rotates the ankle joint body about the roll axis and the pitch axis of the ankle joint joint with respect to the crus part;
A legged robot having one end connected to the ankle joint joint so as to be rotatable about the pitch axis and the other end connected to the knee joint body so as to be rotatable about the pitch axis. Lower limb structure. The ankle joint joint has a cross-shaped main body part that constitutes the roll axis and the pitch axis, and an arm coupled to the main body part,
The leg structure of the legged robot according to claim 3, wherein the one end of the auxiliary link is rotatably connected to the arm.   A legged robot incorporating the lower limb structure of the legged robot according to any one of claims 1 to 4.

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