JP2008200813A - Bipedal walking robot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bipedal walking robot keeping its balance even at the attitude for bending and stretching its body and bending its knee joint. <P>SOLUTION: A main body of a motor 20 is connected with a first knee part pulley 12 turning integrally with a thigh link 10, and a motor shaft 201 is connected with a second knee part pulley 17 turning integrally with a crus link 15. A ratio of diameter of the first knee part pulley 12 to an ankle part pulley 13 provided in an ankle joint part 5 is 1 to 2, and a belt 14 is wound around them. A ratio of diameter of the second knee part pulley 17 to a hip part pulley 18 provided in a hip part 3, is also 1 to 2, and a belt 19 is wound around them. When the motor 20 is operated, and the relation of relative rotation position between both links 10 and 15 is changed, the hip part 3 is turned in the interlocking relationship with the turn of the hip part 3 and the ankle joint part 5, and foot parts 6 and a trunk part 1 are operated to approach each other while keeping the same attitude for each other. For this reason, the trunk part 1 descends while keeping the upright attitude even when the robot bends its knee on a floor surface, and the center of gravity by the trunk part 1 acts substantially vertically and downward to prevent the loss of its balance. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a biped walking robot, and more particularly to a structure of legs of a biped walking robot.

  In recent years, research and development of biped robots that imitate human walking forms have been actively promoted by various companies and research institutions. Biped walking is one of the normal daily movements for humans, but it is not easy to realize this walking form with a robot. Various proposals have been made.

  FIG. 7 is a schematic perspective view showing a joint structure of a leg portion of a conventional general biped robot (see, for example, Patent Document 1). As shown in the figure, as the three axes orthogonal to each other, the front-rear direction of the robot, that is, the traveling direction is defined as the x-axis, the left-right direction is defined as the y-axis, and the height direction is defined as the z-axis. FIG. 8 is a schematic side view for explaining the problems of the conventional biped robot.

  In FIG. 7, the left leg portion 2L and the right leg portion 2R connected to the trunk portion 1 schematically illustrated include a thigh link 52L, 52R, a crus link 53L, 53R, and an ankle link 54L, 54R from above. The upper ends of both leg portions 2L and 2R are connected to each other by a connecting link 51 extending horizontally. As the joints, the hip joint portions 3L, 3R are between the link link 51 and the thigh links 52L, 52R, and the knee joint portions 4L, 4R are between the thigh links 52L, 52R and the crus links 53L, 53R, and the crus link 53L. , 53R and the ankle links 54L and 54R are ankle joint portions 5L and 5R, and the ankle links 54L and 54R are connected to the left foot portion 6L and the right foot portion 6R via the ankle joint portions 5L and 5R.

  The hip joint portions 3L and 3R are motors 61L and 61R that rotate about the x-axis extending in the front-rear direction, motors 62L and 62R that rotate about the y-axis that extend in the left-right direction, and the z-axis. It includes motors 63L and 63R for rotating the leg portions. As a result, the thigh links 52L and 52R can be rotated with respect to the body part 1 (or the connecting link 51) around the three axes of the x axis, the y axis, and the z axis within a predetermined angle range. The knee joint portions 4L and 4R include motors 64L and 64R that rotate around the y-axis extending in the left-right direction. As a result, the lower leg links 53L and 53R are rotatable with respect to the thigh links 52L and 52R within a predetermined angle range around the y axis. The ankle joint portions 5L and 5R include motors 65L and 65R that rotate around the x-axis extending in the front-rear direction, and motors 66L and 66R that rotate around the y-axis extending in the left-right direction. As a result, the ankle links 54L and 54R are rotatable with respect to the crus links 53L and 53R around the two axes of the x-axis and the y-axis within a predetermined angle range.

  Each of the links is operated by driving a plurality of motors provided in the joints 3L, 3R, 4L, 4R, 5L, and 5R at appropriate timings. Leg walking is achieved. Note that modifications such as using an appropriate actuator instead of the motor are possible.

  Here, only the rotation around the y-axis at each joint portion of the leg portions 2L and 2R is considered here. When the biped walking robot takes a posture in which the knee joint portion 4 is bent in a dogleg shape as shown in FIG. 8A, a large load is applied to the knee joint portion 4. Therefore, for example, if the mechanical strength of the knee joint portion 4 is insufficient, as shown in FIG. 8B, the weight of the body portion 1 cannot be supported and the knee joint portion 4 has a large bending angle. May sink. As a result, the center of gravity of the body portion 1 is applied to the rear side (left side in the figure), and thus the load applied to the knee joint portion 4 is increased. As shown in FIG. 8C, this further increases the knee joint portion 4. It becomes a vicious circle that the center of gravity is applied to the rear as the bending of the body increases. As a result, the robot main body tends to fall backward as shown in FIG.

  That is, in the conventional configuration, when the knee joint portion 4 is bent, if the mechanical rigidity of the knee joint portion 4 does not catch up to support the knee joint portion 4, the upper body falls back, which further increases the knee joint portion. There is a problem of increasing the load on the unit 4.

  Further, for example, when the robot is run or jumped, it is necessary to suddenly extend the knee joint portion 4 from a relatively bent state. At this time, not only the knee joint part 4 but also the hip joint part 3 and the ankle joint part 5 must be appropriately driven in accordance with the operation of the knee joint part 4. However, in the conventional configuration, the force and the operating angle applied to the knee joint part 4 and the hip joint part 3 and the ankle joint part 5 are different, so that it is difficult to drive them synchronously especially in a high load and quick operation, and the balance is lost. There is also a problem that it is easy to collapse.

Japanese Patent No. 3729459

  The present invention has been made in view of the above points. The first object of the present invention is to determine the weight of the body part, that is, the center of gravity of the upper body when the knee joint part is bent. It is possible to provide a bipedal walking robot having a leg structure that can guarantee that the robot acts almost vertically downward and has a simple structure. The second object of the present invention is to balance the knee joint, sudden hip movement, etc. by mechanically synchronizing and interlocking the knee joint, hip joint and ankle joint. The object is to provide a biped robot having a leg structure that is not easily broken.

According to a first aspect of the present invention, there is provided a body part, a left and right body connected to the body part via a left and right hip joint part so as to be pivotable in the front-rear direction, and a knee joint part provided in the middle. In a biped robot having a leg and a foot connected to the lower end of the leg via an ankle joint so as to be able to rotate in the front-rear direction, the left and right legs are respectively
a) The upper end is held pivotably about a horizontal axis extending in the left-right direction at the hip joint, and the lower end is held rotatable about the horizontal axis extending in the left-right direction at the knee joint. Thigh link,
b) A crus link having an upper end held rotatably about the horizontal axis at the knee joint and a lower end held pivotable about a horizontal axis extending in the left-right direction at the ankle joint When,
c) a first knee disk that can rotate integrally with the thigh link around the horizontal axis at the knee joint, and an integral with the foot around the horizontal axis at the ankle joint. An ankle disc-shaped body that can be pivoted to each other, and a transmission unit that associates the rotations so that ½ of the pivot angle of the first knee disk-shaped body is the pivot angle of the ankle disc-shaped body A lower rotational power transmission unit including
d) a second knee disk-shaped body that can rotate integrally with the crus link about the horizontal axis at the knee joint, and an integral with the torso about the horizontal axis at the hip joint. A rotatable crotch disk, and a transmission unit that associates the rotations so that one half of the rotation angle of the second knee disk is the rotation angle of the crotch disk, An upper rotational power transmission unit including
e) A driving force is applied to either one so as to change the rotational positional relationship between the thigh link and the lower leg link around the horizontal axis at the knee joint, and the horizontal axis at the hip joint is at the center A driving force is applied to one of the thigh link and the crotch disk so as to change a rotational positional relationship, or the crus link and the ankle disk centered on a horizontal axis at the ankle joint A driving source for applying a driving force to one of the two so as to change the rotational positional relationship with the object
It is characterized by having.

  As one embodiment of the biped robot according to the first invention, in the lower rotational power transmission unit and the upper rotational power transmission unit, the disk-like body is a pulley, and the transmission unit is between two pulleys. It is a wound string-like or belt-like transmission body, and the configuration is such that the diameter of the pulley provided at the knee joint is half the diameter of the pulley provided at the hip joint and the ankle joint. Can do.

  That is, a winding transmission mechanism such as a belt transmission mechanism, a rope transmission mechanism, or a chain transmission mechanism may be used as the lower rotational power transmission unit and the upper rotational power transmission unit. In such a simple winding transmission mechanism, the rotation angle of each shaft is determined by the diameter of the pulley. Therefore, by setting the pulley diameter as described above, the rotation angle of the first knee disk-shaped body can be reduced. It can be assured that 1/2 is the rotation angle of the ankle disk-shaped body and 1/2 of the rotation angle of the second knee disk-shaped body is the rotation angle of the crotch disk-shaped body.

  The drive source can be provided at any of the knee joint, hip joint, or ankle joint, but usually another drive for realizing an operation other than knee bending at the hip joint or ankle joint. A source is installed. Therefore, it is preferable to provide the drive source at the knee joint. In that case, the drive source is a motor having a rotating shaft, and the main body of the motor is connected to one of the first knee disk or the second knee disk at the knee joint. The rotating shaft body may be connected to the other of the first knee disk-shaped body or the second knee disk-shaped body.

  In the biped walking robot according to the first invention, when the thigh link in an upright state is rotated by an angle 2α so as to incline backward about the horizontal axis of the knee joint, for example, by the rotational power from the drive source, Together with this, the first knee disk-shaped body of the lower rotational power transmission section also rotates. This turning motion is transmitted to the ankle disc-like body through the transmission portion of the lower rotational power transmission portion, whereby the foot portion turns in the same direction by an angle α which is a half of the turning angle of the thigh link. It will be. Therefore, the lower leg link tilts forward about the horizontal axis of the ankle joint by the same angle α as the rotation angle of the foot, the thigh link tilts by an angle α with respect to the vertical line, and the leg part has a cross-shaped character. In a bent state.

  On the other hand, when the thigh link is tilted rearward, the position of the horizontal axis of the hip joint also changes relative to the position of the horizontal axis of the knee joint. Are not the same, the crotch disk is rotated by an angle α at the hip joint. That is, for example, when the driving force is applied by the driving source so as to change the rotational positional relationship between the thigh link and the crus link at the knee joint, the hip joint and the ankle joint rotate in conjunction with the rotation at the knee joint. As a result, the foot part and the body part move toward and away from each other while maintaining the posture of each other. For this reason, even if the leg portion is bent in a dogleg shape with the knee joint portion interposed therebetween, the trunk portion does not tilt and maintains an upright state when the foot portion is in a state of landing on the floor surface. If the flexion of the hip joint portion increases, the trunk portion descends while maintaining an upright state (that is, approaches the floor surface), so that it is guaranteed that the center of gravity by the trunk portion always acts substantially vertically downward.

According to a second aspect of the present invention, there is provided a body part, a left and right body connected to the body part via a left and right hip joint part so as to be pivotable in the front-rear direction, and a knee joint part provided in the middle. In a biped robot having a leg and a foot connected to the lower end of the leg via an ankle joint so as to be able to rotate in the front-rear direction, the left and right legs are respectively
a) The upper end is held rotatably about a horizontal axis extending in the left-right direction in the hip joint, and the lower end is rotatable about the first horizontal axis extending in the left-right direction in the knee joint A retained thigh link;
b) At the knee joint, the upper end is held pivotably about a second horizontal axis extending in the left-right direction located below the first horizontal axis, and extended in the left-right direction at the ankle joint A crus link with a lower end held rotatably about a horizontal axis
c) A second knee disk-shaped body that can be rotated around the second horizontal axis at the knee joint and a foot that can rotate integrally with the foot around the horizontal axis at the ankle joint. Lower anterior disc power, and a transmission portion that associates the rotations of the second knee disc and the ankle disc so as to be equal to each other. A transmission part;
d) A first knee disk-shaped body that can rotate around the first horizontal axis at the knee joint and a body that can rotate integrally with the body around the horizontal axis at the hip joint. Upper rotational power transmission including a crotch disk and a transmission unit that associates the rotations of the first knee disk and the crotch disk so as to be equal to each other. And
e) a connecting portion at the knee joint for connecting the first knee disk and the second knee disk;
f) A driving force is applied to one of the thigh link and the hip joint in such a manner that the rotational positional relationship between the thigh link and the first knee disk-shaped body around the first horizontal axis at the knee joint is changed. A first driving unit that applies a driving force to one of the thigh link and the crotch disc-like body so as to change a rotational positional relationship about a horizontal axis at a portion;
g) A driving force is applied to one of the ankles so as to change the rotational positional relationship between the lower leg link and the second knee disk-shaped body around the second horizontal axis at the knee joint, or the ankle A second drive unit that applies a driving force to either one of the lower leg link and the ankle disk-like body around the horizontal axis at the joint so as to change the rotational positional relationship;
It is characterized by having.

  As one embodiment of the biped walking robot according to the second invention, in the lower rotational power transmission unit and the upper rotational power transmission unit, the disk-shaped body is a pulley, and the transmission unit is between two pulleys. It is a string-like or belt-like transmission wound around the knee, and the diameter of the pulley provided at the knee joint and the diameter of the pulley provided at the hip joint and the ankle joint can be made equal. .

  As in the first invention, a winding transmission mechanism such as a belt transmission mechanism, a rope transmission mechanism, or a chain transmission mechanism may be used as the lower rotational power transmission unit and the upper rotational power transmission unit. In such a simple winding transmission mechanism, the rotation angle of each shaft is determined by the diameter of the pulley. Therefore, by setting the pulley diameter as described above, the rotation angle of the first knee disk-shaped body It can be assured that the rotation angle of the ankle disk is equal, and the rotation angle of the second knee disk is equal to the rotation angle of the crotch disk.

  In the biped walking robot according to the second aspect of the invention, when the knee joint is bent, for example, the thigh link and the crus link in an upright state are rotated in opposite directions. Since the first knee disk-shaped body and the second knee disk-shaped body are connected by the connecting portion, the disk-shaped body is also centered on the first horizontal axis and the second horizontal axis during the rotation. Does not rotate. Therefore, even when the thigh link and the crus link are tilted, the crotch disk-like body and the ankle disk-like body are not rotated around the horizontal axis via the transmission body. Specifically, for example, when the lower rotational power transmission unit and the upper rotational power transmission unit are wound transmission mechanisms, the transmission body substantially travels only by changing the winding position of the transmission body with respect to the disk-shaped body. Without doing so, the crotch disc and the ankle disc retain their original rotational positions. As a result, the trunk part connected to the hip joint part maintains the same posture as before the knee joint part is bent, so that the center of gravity by the trunk part acts substantially vertically downward.

  In the biped walking robot according to the second aspect of the invention, one of the first drive unit and the second drive unit is a drive source, and the other of the first drive unit and the second drive unit is the drive source. It is possible to employ a configuration using a driving force generated so that the driving force transmitting portion rotates in a direction opposite to the rotation direction by the driving source in response to the rotational driving force. Here, the driving force transmission unit meshes with the first gear that can rotate about the first horizontal axis at the knee joint and the first gear that can rotate about the second horizontal axis. And a second gear.

  According to this configuration, for example, only one motor may be used as the drive source. Further, since it is mechanically guaranteed that the thigh link and the crus link rotate synchronously in opposite directions, the control is simple.

  In the biped walking robot according to the second aspect of the present invention, the first drive unit and the second drive unit may be independent drive sources.

  According to the biped robots according to the first and second aspects of the invention, when the knee joint is in a bent posture, it is guaranteed that the center of gravity by the torso acts almost vertically downward regardless of the angle of the knee joint. Is done. Therefore, even when the mechanical rigidity of the knee joint portion is insufficient, it is possible to prevent the center of gravity from hanging backward and falling down. Further, according to the biped walking robot according to the first and second inventions, the rotation operation of the torso portion at the hip joint portion and the rotation operation of the foot portion at the ankle joint portion are referred to as the rotation operation of the knee joint portion. It can be mechanically linked or tuned. For this reason, for example, even when the knee joint is suddenly extended from a state where the knee joint portion is greatly bent during a biped running operation or a jump operation, the balance is not easily lost, and the running and jumping can be performed stably.

[First embodiment]
A biped walking robot according to an embodiment (first embodiment) of the first invention will be described with reference to FIGS. FIG. 1 is a schematic perspective view showing the principle structure of the main part centering on the knee joint part of one leg of the biped robot of the present embodiment. Although not shown here, the structure of the other leg is basically the same except that it is also symmetrical. 2 and 3 are schematic diagrams for explaining the operation when the knee joint portion is bent in the leg joint structure.

  This leg portion 2 is a component of the thigh link 10 between the hip joint portion 3 and the knee joint portion 4, the lower leg link 15 between the knee joint portion 4 and the ankle joint portion 5, and the hip joint portion 3. And a crotch pulley (rotary disc-like body in the present invention) 18 that rotates about the first horizontal axis 3A and a knee joint 4 that rotates independently about the second horizontal axis 4A. One knee pulley (first knee disc-like body in the present invention) 12 and second knee pulley (second knee disc-like body in the present invention) 17 and the ankle joint portion 5 and the third horizontal axis 5A An ankle pulley (ankle disc-like body in the present invention) 13 that rotates around the center, an upper belt (a transmission part in the present invention) 19 wound around a crotch pulley 18 and a second knee pulley 17; , A lower belt wound around the first knee pulley 12 and the ankle pulley 13 (this It includes a transmission unit) 14, a motor 20 as a driving source for bending the knee joint 4, the in.

  Here, the crotch pulley 18 and the ankle pulley 13 have the same diameter 2d, and the first knee pulley 12 and the second knee pulley 17 have the same diameter d. That is, the diameters of the first knee pulley 12 and the second knee pulley 17 are ½ of the diameters of the ankle pulley 13 and the crotch pulley 18. Thus, when the first knee pulley 12 and the second knee pulley 17 are rotated by a predetermined angle α around the second horizontal axis 4A, the ankle pulley 13 via the lower belt 14 and the upper belt 19 is obtained. The crotch pulley 18 is configured to rotate by an angle α / 2. The pulleys 12, 13, 17, and 18 and the belts 14 and 19 may conduct driving force only by friction. For example, a timing pulley and a timing belt are used so as not to cause slip. Preferably.

  The main body (exterior) of the motor 20 is fixed to the first knee pulley 12, and the motor shaft 201 that rotates on the second horizontal axis 4 </ b> A is connected to the second knee pulley 17 and at the upper end of the crus link 15. It is connected. On the other hand, the first knee pulley 12 is connected to the lower end of the thigh link 10. The upper end of the thigh link 10 is located on the first horizontal axis 3 </ b> A, the crotch pulley 18 is rotatably held on the first horizontal axis 3 </ b> A, and the body part 1 is connected to the crotch pulley 18. The lower end of the crus link 15 is positioned on the third horizontal axis 5A, the ankle pulley 13 is rotatably held on the third horizontal axis 5A, and the ankle pulley 13 has a lower surface in contact with the floor surface. Part 6 is connected. Accordingly, if the hip joint 3 is not rotated by the motors 62L and 62R shown in FIG. 7 and the ankle joint 5 is not rotated by the motors 66L and 66R, the body 1 is also moved when the crotch pulley 18 is rotated. When the ankle pulley 13 is rotated, the foot 6 is also rotated.

  The operation at the time of bending the knee joint portion 4 in the leg structure having the above configuration will be described with reference to FIG. FIG. 3 is a schematic side view of the main part of the leg structure, wherein (a), (c), and (e) are states in which the knee joint part 4 is straightened, and (b), (d), and (f). ) Shows a state when the knee joint part 4 is bent. In addition, in order to make it easy to understand the rotation operation of the pulleys 12, 13, 17, and 18, two opposite areas of the area obtained by dividing one round into four are shaded.

  Now, considering the case where the biped robot is standing upright and the leg 2 is straightened, as shown in FIG. 3A, the thigh link 10 and the crus link 15 are in the second horizontal direction. It is arranged linearly across the axis 4A. From this state, assuming that the position of the thigh link 10 is fixed and the motor shaft 201 is rotated counterclockwise by an angle 2θ by the driving force of the motor 20, it is shown in FIG. As described above, the crus link 15 whose upper end is fixed to the motor shaft 201 rotates counterclockwise by the angle 2θ about the second horizontal axis 4A.

  Since the second knee pulley 17 is also fixed to the motor shaft 201, when the motor shaft 201 is rotated counterclockwise by an angle 2θ as described above, as shown in FIG. The part pulley 17 is also rotated by an angle 2θ around the second horizontal axis 4A. This rotational movement is transmitted to the crotch pulley 18 via the upper belt 19, but since the diameters of the pulleys 17 and 18 are different as described above, the crotch pulley 18 has the angle of the second knee pulley 17. Only turn by half. Therefore, the crotch pulley 18 rotates about the first horizontal axis 3A by an angle θ in the counterclockwise direction. The body 1 connected to the crotch pulley 18 also rotates counterclockwise about the first horizontal axis 3A by the same angle θ.

  Since the ankle pulley 13 is pivotally supported on the third horizontal axis 5A at the lower end of the crus link 15, when the crus link 15 is rotated as described above, the position of the third horizontal axis 5A is accordingly accompanied. In other words, the center of rotation of the ankle pulley 13 also rotates about the second horizontal axis 4A. On the other hand, if the position of the thigh link 10 is fixed, the first knee pulley 12 does not rotate, so that the center of rotation of the ankle pulley 13 is at an angle 2θ as shown in FIG. When rotated counterclockwise, the winding position of the lower belt 14 changes on the circumferential surface of the first knee pulley 12, so that the lower belt 14 is fed out. Here, since the diameter of the first knee pulley 12 is ½ of the diameter of the ankle pulley 13, the ankle pulley 13 is rotated counterclockwise by the angle θ about the third horizontal axis 5A. In this state, the ankle pulley 13 absorbs the extension of the lower belt 14. Therefore, the ankle pulley 13 rotates about the third horizontal axis 5A in the counterclockwise direction by an angle θ. Then, the foot 6 connected to the ankle pulley 13 also rotates counterclockwise about the third horizontal axis 5A by the same angle θ.

  That is, as shown in FIGS. 3A, 3C, and 3E, when the state where the knee joint portion 4 is extended straight is considered as an angle 0, the knee joint portion 4 is bent by an angle 2θ therefrom. When the motor 20 is operated, the body 1 rotates about the first horizontal axis 3A of the hip joint 3, and the foot 6 rotates about the third horizontal axis 5A of the ankle joint 5 by the angle θ in the same direction. .

  FIG. 2 schematically shows a state where the bending operation of the knee joint portion 4 as described above is performed from an upright posture. As shown in FIG. 2 (a), the motor 20 is operated to rotate the motor shaft 201 by 2θ from a state where the robot is in an upright posture, that is, a state where the opening angle of the knee joint portion 4 is 180 °. When the knee joint portion 4 is bent to a state where the opening angle of the knee joint portion 4 is 2α (α <90 °), as shown in FIG. 2B, the horizontal line on the first horizontal axis 3A and the thigh link 10 And the angle between the horizontal line on the third horizontal axis 5A and the crus link 15 are both α. Then, the body part 1 rotates with respect to the thigh link 10 about the first horizontal axis 3A by an angle θ (90−α °), and the foot part 6 about the third horizontal axis 5A has a leg link 15 with an angle θ. , The body part 1 descends while maintaining the posture of standing in the substantially vertical direction. This is the same even when the knee joint 4 is bent deeply as shown in FIG.

  In other words, according to the leg structure of the biped robot of the first embodiment, both the ankle pulley 13 and the crotch pulley 18 do not rotate even when the knee joint 4 is bent. The state before bending of the joint part 4 is maintained, so that the center of gravity by the body part 1 is not applied to the rear side but substantially vertically downward. Therefore, in various operating states such as walking, running, and jumping, it is difficult to lose balance even if the knee joint portion 4 is greatly bent, and posture control is facilitated.

[Second Embodiment]
Next, a bipedal walking robot according to an embodiment (second embodiment) of the second invention will be described with reference to FIGS. FIG. 4 is a schematic perspective view showing the principal structure of the main part centering on the knee joint part of one leg of the biped robot of this embodiment, and FIG. 5 bends the knee joint part in this leg joint structure. It is a schematic diagram for demonstrating the operation | movement at the time.

  This leg portion 2 is a component of the thigh link 30 between the hip joint portion 3 and the knee joint portion 4, the lower leg link 37 between the knee joint portion 4 and the ankle joint portion 5, and the hip joint portion 3. A crotch pulley 32 that rotates about the horizontal axis 3A, a knee upper pulley 33 that rotates around the second upper horizontal axis 4A1 at the knee joint 4, and a second that exists at the knee joint 4. A lower knee pulley 39 that rotates about the lower horizontal axis 4A2, an ankle pulley 38 that rotates at the ankle joint 5 about the third horizontal axis 5A, a crotch pulley 32, and an upper knee pulley 33; An upper belt 34 wound around the lower belt 40, a lower belt 40 wound around the lower knee pulley 39 and the ankle pulley 38, one motor 35 which is a drive source for bending the knee joint portion 4, and a first motor 35. 2 First attached to the motor shaft 351 on the upper horizontal axis 4A1 Including the A 42, and a second gear 43 to first gear 42 meshed rotates about a second lower horizontal axis 4A2. The knee upper pulley 33 and the knee lower pulley 39 are connected by a connecting portion 36 (in FIG. 4, they are connected via a main body of a motor 35 described later).

  In this second embodiment, pulleys 32 and 33 and pulleys 38 and 39 connected by belts 34 and 40, respectively, have the same diameter. Thus, when the upper knee pulley 33 and the lower knee pulley 39 are rotated by a predetermined angle α about the second upper horizontal axis 4A1 and the second lower horizontal axis 4A2, respectively, via the upper belt 34 and the lower belt 40. The crotch pulley 32 and the ankle pulley 38 are configured to rotate by the same angle α. The pulleys 32, 33, 38, 39 and the belts 34, 40 may conduct driving force only by friction, but use a timing pulley and a timing belt to prevent slippage. Is preferred.

  The main body (exterior) of the motor 35 is fixed to the upper knee pulley 33, the motor shaft 351 of the motor 35 rotating on the second upper horizontal axis 4 </ b> A <b> 1 is connected to the lower end of the thigh link 30, and further to the first gear 42. It is connected. Therefore, when the motor shaft 351 is rotated by the motor 35, the thigh link 30 is rotated by the same angle in the same direction as the motor shaft 351 in conjunction therewith. The transmission ratio between the first gear 42 and the second gear 43 is 1: 1, and the central axis of the second gear 43 is connected to the upper end of the crus link 37 on the second lower horizontal axis 4A2. Therefore, when the motor shaft 351 is rotated and the thigh link 30 is rotated about the second upper horizontal axis 4A1, the lower leg link 37 is rotated by the same angle about the second upper horizontal axis 4A1 in the opposite direction. To do.

  The upper end of the thigh link 30 is located on the first horizontal axis 3 </ b> A, a crotch pulley 32 is rotatably held on the first horizontal axis 3 </ b> A, and the body part 1 is connected to the crotch pulley 32. Further, the lower end of the crus link 37 is positioned on the third horizontal axis 5A, the ankle pulley 38 is rotatably held on the third horizontal axis 5A, and the lower surface of the ankle pulley 38 is in contact with the floor surface. Part 6 is connected. Accordingly, assuming that the hip joint portion 3 is not rotated by the motors 62L and 62R and the ankle joint portion 5 is not rotated by the motors 66L and 66R shown in FIG. When the ankle pulley 38 is rotated, the foot 6 is also rotated. These points are the same as in the first embodiment.

  The operation at the time of bending the knee joint portion 4 in the leg structure having the above configuration will be described with reference to FIG. 5A and 5C show a state in which the knee joint portion 4 is straightened, and FIGS. 5B and 5D show a state in which the knee joint portion 4 is bent. In addition, in order to make it easy to understand the rotation operation of the pulleys 32, 33, 38, and 39, two opposing areas in a region obtained by dividing one round into four are shaded.

  Now, considering the case where the biped robot is standing upright and the leg 2 is straightened, as shown in FIG. 5 (a), the thigh link 30 and the crus link 37 are the second upper part. It is arranged linearly across the horizontal axis 4A1 and the second lower horizontal axis 4A2. From this state, when the motor shaft 351 is rotated clockwise by an angle θ by the driving force of the motor 35, the thigh link whose lower end is fixed to the motor shaft 351 is shown in FIG. 30 rotates about the second upper horizontal axis 4A1 by an angle θ in the clockwise direction. In conjunction with this, the crus link 37 whose upper end is fixed to the central axis of the second gear 43 rotates about the second lower horizontal axis 4A2 by an angle θ in the counterclockwise direction.

  When the lower leg link 37 is rotated as described above, the third horizontal axis 5A moves rearwardly from directly below the second lower horizontal axis 4A2 as shown in FIG. The extension direction of is also slanted. At this time, the winding position of the lower belt 40 changes in the ankle pulley 38 and the lower knee pulley 39, but the lower belt 40 does not travel because the diameters are the same. Accordingly, the rotational positions of the pulleys 38 and 39 remain the same as before the knee bending, and the lower knee pulley 39 does not rotate around the second lower horizontal axis 4A2. As a result, the upper knee pulley 33 connected by the connecting portion 36 does not rotate, and the whole lowers in a state where the positional relationship between the lower knee pulley 39 and the upper knee pulley 33 is maintained. .

  In the crotch pulley 32 and the knee upper pulley 33, the winding position of the upper belt 34 changes, but the upper belt 34 does not run. Accordingly, similarly to the upper knee pulley 33, the crotch pulley 32 does not rotate. That is, regardless of the bending angle of the knee joint part 4, the pulleys 38, 39, 33, and 32 all maintain the pre-bending state of the knee joint part 4 without rotating. Therefore, the center of gravity due to the body portion 1 is not on the rear side but on the substantially downward vertical direction. That is, the center of gravity is applied in the same manner as in the first embodiment, and even when the knee joint portion 4 is greatly bent to walk, run, or jump, the balance is hardly lost and posture control is facilitated.

[Third embodiment]
Next, a bipedal walking robot according to a third embodiment, which is a modification of the second embodiment, will be described with reference to FIG. FIG. 6 is a schematic perspective view showing the principal structure of the main part centering on the knee joint part of one leg part of the biped walking robot of this embodiment.

  In the leg portion 2 of the biped robot according to the third embodiment, the pulleys and the belt are arranged in the same manner as in the second embodiment. The difference is that instead of using the first gear 42 and the second gear 43 to transmit the driving force of the motor 35 to the crus link 37, a motor 41 having a motor shaft 41 that rotates on the second lower horizontal axis 4A2. Is provided independently of the motor 35. That is, the main body (exterior) of the motor 41 added here is fixed to the lower knee pulley 39, and the motor shaft 41 is connected to the upper end of the crus link 37.

  As a basic operation when the knee joint section 4 is bent, the two motors 35 and 41 are controlled so that their motor shafts 351 and 411 rotate in the opposite rotation directions and in synchronism with the same angle. Is done. As a result, the same knee flexion motion as that of the biped robot of the second embodiment described above is achieved, and the same effect as that of the second embodiment is achieved.

  Furthermore, in this configuration, the inclination angles of the thigh link 30 and the crus link 37 with respect to the vertical line are determined by the motors 35 and 41 that are independently driven. Can be driven in the direction in which the knee joint bends, and the other motor can be driven in the direction in which the knee joint extends. If such control is performed, not only the knee joint part 4 can be bent in a dogleg shape, but also, for example, the leg part 2 can be swung forward or backward with the leg part 2 stretched almost straight. The degree of freedom of operation of the unit 2 is increased. In general, in order to walk, the knee joint portion 4 is bent and extended, and the hip joint portion 3 is turned by the motors 62L and 62R shown in FIG. 7 and the ankle joint portion 5 is turned by the motors 66L and 66R. It is necessary to carry out, and control is complicated. On the other hand, in the configuration of the third embodiment, walking is realized without actively rotating the hip joint portion 3 and the ankle joint portion 5 by appropriately controlling the two motors 35 and 41. It is also possible. Furthermore, it is possible to realize a walking motion with a simpler structure in which an actuator such as a motor is not provided in the hip joint 3 or the ankle joint 5.

  It should be noted that each of the above embodiments is merely an example of the present invention, and it is obvious that modifications, corrections, and additions as appropriate within the scope of the present invention are included in the scope of the claims of the present application.

  For example, in the first to third embodiments, a motor as a driving source is installed in the knee joint portion 4, and the thigh links 10 and 30 centered on the knee joint portion 4 and the lower leg links 15 are provided by the driving force of the motor. Rotation relative to 37 is performed. However, in any of the embodiments, it is guaranteed that the hip joint portion 3, the knee joint portion 4 and the ankle joint portion 5 operate in synchronism mechanically as described above. May be driven so as to change the relative rotational positional relationship (angle) between the upper ends of the pulleys 18 and 32, and the lower ends of the lower leg links 15 and 37 and the pulleys 13 and 38 at the ankle joint 5. You may drive so that a relative rotational positional relationship (angle) may be changed. In the configuration of the third embodiment, two motors may be transferred to the hip joint 3 and the ankle joint 5 one by one, or only one of the two motors may be the hip joint 3 or It can also be moved to the ankle joint 5.

  Further, for example, in the above-described embodiment, the pulley and the belt are used as the rotational power transmission mechanism. However, a winding transmission mechanism such as a chain transmission mechanism can be used instead. Further, a gear transmission mechanism or the like can be used instead of the winding transmission mechanism. When such a transmission mechanism is used, the rotation angle ratio of the shaft in the middle of the transmission mechanism can be arbitrarily determined, but both ends thereof, that is, the axis on the horizontal axis 3A in the hip joint 3 and the knee joint 4 The rotation angle ratio with the axis on the second horizontal axis 4A (or the second upper horizontal axis 4A1) at the second axis, and the axis on the horizontal axis 5A at the ankle joint 5 and the second horizontal axis 4A (or the first at the knee joint 4). 2) It is necessary to maintain the predetermined relationship as described above with the rotation angle ratio with the axis on the lower horizontal axis 4A2).

The schematic perspective view which shows the principal structure of the principal part centering on the knee joint part of one leg part of the biped walking robot by 1st Example which is one Example of 1st invention. The schematic diagram for demonstrating the operation | movement at the time of bending a knee joint part in the leg part joint structure of FIG. The schematic diagram for demonstrating the operation | movement at the time of bending a knee joint part in the leg part joint structure of FIG. The schematic perspective view which shows the principal structure of the principal part centering on the knee joint part of one leg part of the biped walking robot by 2nd Example which is one Example of 2nd invention. The schematic diagram for demonstrating the operation | movement at the time of bending a knee joint part in the leg part joint structure of FIG. The schematic perspective view which shows the principal structure of the principal part centering on the knee joint part of one leg part of the bipedal walking robot by 3rd Example which is another Example of 2nd invention. The schematic perspective view which shows the joint structure of the leg part of the conventional common biped robot. The schematic diagram for demonstrating the problem of the conventional leg part structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Torso part 2 ... Leg part 3 ... Hip joint part 4 ... Knee joint part 5 ... Ankle joint part 6 ... Foot part 10, 30 ... Thigh link 12 ... 1st knee pulley 13, 38 ... Ankle pulley 14, 40 ... Lower belt 15, 37 ... Lower leg link 17 ... Second knee pulley 18, 32 ... Crotch pulley 19, 34 ... Upper belt 20, 35, 41 ... Motor 201, 351, 411 ... Motor shaft 33 ... Upper knee pulley 36 ... Connecting part 39 ... Lower knee pulley 42 ... First gear 43 ... Second gear 3A, 4A, 4A1, 4A2, 5A ... Horizontal axis

Claims (8)

The body part, the left and right leg parts that are connected to the body part via the left and right hip joint parts so as to be pivotable in the front-rear direction, and the knee joint part is provided in the middle, and the lower end of the leg part via the ankle joint part In a biped walking robot having legs that are pivotably connected in the front-rear direction, the left and right legs are respectively
a) The upper end is held pivotably about a horizontal axis extending in the left-right direction at the hip joint, and the lower end is held rotatable about the horizontal axis extending in the left-right direction at the knee joint. Thigh link,
b) A crus link having an upper end held rotatably about the horizontal axis at the knee joint and a lower end held pivotable about a horizontal axis extending in the left-right direction at the ankle joint When,
c) a first knee disk that can rotate integrally with the thigh link around the horizontal axis at the knee joint, and an integral with the foot around the horizontal axis at the ankle joint. An ankle disc-shaped body that can be pivoted to each other, and a transmission unit that associates the rotations so that ½ of the pivot angle of the first knee disk-shaped body is the pivot angle of the ankle disc-shaped body A lower rotational power transmission unit including
d) a second knee disk-shaped body that can rotate integrally with the crus link about the horizontal axis at the knee joint, and an integral with the torso about the horizontal axis at the hip joint. A rotatable crotch disk, and a transmission unit that associates the rotations so that one half of the rotation angle of the second knee disk is the rotation angle of the crotch disk, An upper rotational power transmission unit including
e) A driving force is applied to either one so as to change the rotational positional relationship between the thigh link and the lower leg link around the horizontal axis at the knee joint, and the horizontal axis at the hip joint is at the center A driving force is applied to one of the thigh link and the crotch disk so as to change a rotational positional relationship, or the crus link and the ankle disk centered on a horizontal axis at the ankle joint A driving source for applying a driving force to one of the two so as to change the rotational positional relationship with the object
A biped walking robot characterized by comprising:   In the lower rotational power transmission unit and the upper rotational power transmission unit, the disk-like body is a pulley, and the transmission unit is a string-like or belt-like transmission wound around two pulleys. The biped walking robot according to claim 2, wherein a diameter of a pulley provided at the knee joint portion is ½ of a diameter of a pulley provided at the hip joint portion and the ankle joint portion.   The drive source is a motor having a rotating shaft, and the main body of the motor is connected to one of the first knee disk and the second knee disk in the knee joint, and The bipedal walking robot according to claim 1 or 2, wherein a moving shaft body is connected to the other of the first knee disk-shaped body or the second knee disk-shaped body. The body part, the left and right leg parts that are connected to the body part via the left and right hip joint parts so as to be pivotable in the front-rear direction, and the knee joint part is provided in the middle, and the lower end of the leg part via the ankle joint part In a biped walking robot having legs that are pivotably connected in the front-rear direction, the left and right legs are respectively
a) The upper end is held rotatably about a horizontal axis extending in the left-right direction in the hip joint, and the lower end is rotatable about the first horizontal axis extending in the left-right direction in the knee joint A retained thigh link;
b) At the knee joint, the upper end is held pivotably about a second horizontal axis extending in the left-right direction located below the first horizontal axis, and extended in the left-right direction at the ankle joint A crus link with a lower end held rotatably about a horizontal axis
c) A second knee disk-shaped body that can be rotated around the second horizontal axis at the knee joint and a foot that can rotate integrally with the foot around the horizontal axis at the ankle joint. Lower anterior disc power, and a transmission portion that associates the rotations of the second knee disc and the ankle disc so as to be equal to each other. A transmission part;
d) A first knee disk-shaped body that can rotate around the first horizontal axis at the knee joint and a body that can rotate integrally with the body around the horizontal axis at the hip joint. Upper rotational power transmission including a crotch disk and a transmission unit that associates the rotations of the first knee disk and the crotch disk so as to be equal to each other. And
e) a connecting portion at the knee joint for connecting the first knee disk and the second knee disk;
f) A driving force is applied to one of the thigh link and the hip joint in such a manner that the rotational positional relationship between the thigh link and the first knee disk-shaped body around the first horizontal axis at the knee joint is changed. A first driving unit that applies a driving force to one of the thigh link and the crotch disc-like body so as to change a rotational positional relationship about a horizontal axis at a portion;
g) A driving force is applied to one of the ankles so as to change the rotational positional relationship between the lower leg link and the second knee disk-shaped body around the second horizontal axis at the knee joint, or the ankle A second drive unit that applies a driving force to either one of the lower leg link and the ankle disk-like body around the horizontal axis at the joint so as to change the rotational positional relationship;
A biped walking robot characterized by comprising:   In the lower rotational power transmission unit and the upper rotational power transmission unit, the disk-like body is a pulley, and the transmission unit is a string-like or belt-like transmission wound around two pulleys. The biped robot according to claim 4, wherein a diameter of a pulley provided in the knee joint part and a diameter of a pulley provided in the hip joint part and the ankle joint part are made equal to each other.   One of the first driving unit and the second driving unit is a driving source, and the other of the first driving unit and the second driving unit receives a rotational driving force of the driving source, and the driving force transmitting unit receives the rotational driving force. The bipedal walking robot according to claim 4, wherein a driving force generated so as to rotate in a direction opposite to a rotation direction by the driving source is used.   The driving force transmission unit includes a first gear that is rotatable about a first horizontal axis at the knee joint, and a second gear that is rotatable about the second horizontal axis and meshes with the first gear. The biped robot according to claim 6, further comprising a gear.   The biped robot according to claim 4, wherein the first driving unit and the second driving unit are independent driving sources.

Images