JP3176711B2 - Foot structure of a legged walking robot - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foot structure of a legged walking robot, and more particularly, to a foot structure designed to increase the stability of a walking robot.

[0002]

2. Description of the Related Art Conventionally, various types of legged walking robots have been proposed. Among them, a technology applicable to an autonomous bipedal legged walking robot is disclosed in No. 97005 and JP-A-62
There is a technique described in Japanese Patent Application Laid-Open No. 970006/1995, and in particular, as a foot structure of a biped walking type legged walking robot, the present applicant has already proposed a technique disclosed in Japanese Patent Application Laid-Open No. 3-184787. .

[0003]

Among the legged walking robots, a bipedal walking type robot is inherently low in stability, and in addition to the state of a walking surface such as the ground to be walked, the surrounding state, and the walking state. Depending on the speed and the like, it is often difficult to ensure stability during walking. In other words, it is relatively easy to maintain stability when walking at low speed on a horizontal plane, but when walking up and down stairs or when walking at high speed, walking with two feet is unstable. It is easy to be.

As one measure for increasing the stability during walking in a bipedal legged walking robot, it is conceivable to design the foot so that the contact area with the walking surface becomes large. However, simply increasing the foot may adversely affect stability depending on the walking situation. For example, when the walking surface is a staircase, the staircase often has a recessed protrusion at the step portion of each step. There is a strong possibility that the toe side of the foot interferes and falls. Also, when the walking speed is high, if the foot is large, interference is liable to occur and a fall is likely to occur. In addition, various situations can be considered, but in any case, simply designing the foot large
It is not a fundamental solution for increasing walking stability.

[0005] The present invention has been made in view of the above circumstances, and even if the state of the walking surface or the walking speed changes.
It is a basic object of the present invention to provide a foot structure capable of always maintaining walking stability.

[0006]

Means for Solving the Problems In order to solve the above-mentioned problems, in the present invention, basically, the first aspect of the present invention is described.
As shown, at least one of the co-when a movable leg 2, in the movable leg of the foot structure provided walking freely and the legged walking robot 1 foot 22 at the tip, before
An operating mechanism 72 is attached to the foot body 100 and the foot body.
Foot piece 10 movably attached via the
2A, 102B, 102C, 102D, 102E, 10
2F, 102G, 102H
Said movable foot piece via a kinematic mechanism, the ankle joint center position and distance <br/> away A in <br/> ankle joint center position or Lalo bot traveling direction last Tanma near the foot body or Lalo ratio a / B between the distance B bot to the traveling direction foremost end is configured to move in a direction that varies.

[0007]

According to the foot structure of the present invention, the vicinity of the foot main body is provided.
From the ankle joint center position 23 to the end of the robot
A is the distance from the center of the ankle joint and the robot is
Let B be the distance to the front end in the traveling direction. More specifically
Is parallel to the robot traveling direction from the center position 23 of the ankle joint on the movable leg 2 to the rearmost position (the rearmost position in the robot traveling direction) of the effective ground plane 109 of the foot 22, as shown in FIG. The projected distance to the vertical plane is defined as A, and a vertical plane parallel to the robot traveling direction from the center position 23 of the ankle joint to the foremost end of the effective ground plane 109 of the foot 22 (the foremost end in the traveling direction of the robot). Let B be the projection distance of. Here, when the front and rear ends of the effective contact surface of the foot 22 are included in a vertical plane passing through the ankle joint center position 23 and parallel to the traveling direction of the robot, the ankle joint The actual spatial distance from the center position 23 to each of the front end and the rear end immediately corresponds to the distances A and B. However, in the actual foot, the front end of the effective contact surface of the foot 22 and In many cases, the position of the rear end is not included in a vertical plane passing through the center of the ankle joint and parallel to the traveling direction of the robot (for example, in the case of FIGS.
In this case, each component of the actual spatial distance from the ankle joint center position 23 to the front end position and the rear end position in the direction parallel to the robot traveling direction is the aforementioned projection distance A,
B. However, in the following description, for the sake of simplicity, “distance A from the center of the ankle joint to the rearmost end of the ground contact surface in the direction of robot movement” and “the distance from the center of the ankle joint to the foremost end of the ground contact surface in the direction of robot movement” will be described. The expression "distance B" is used.

In the foot structure of the present invention, the ratio A / B of the distance A and the distance B can be changed by operating the movable foot piece by the operating mechanism. The value of the ratio A / B has a great effect on the stability of walking of the robot depending on the walking situation. In the structure of the present invention, the ratio A / B is selected to an optimum value that can maximize the stability of walking according to a walking situation such as ascent of a stair, descent of a stair, or a walking speed. be able to.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below, taking a bipedal walking robot as an example of a legged mobile robot. FIG. 2 is an explanatory skeleton diagram schematically showing the whole of the robot 1. The left and right link-shaped movable legs 2 are 6
(Each joint for convenience of understanding,
Shown by the electric motor driving it). These six joints are, in order from the top, joints 10R and 10L for rotation of the hip leg (around the z-axis) (R on the right, L on the left; the same applies hereinafter), and the roll direction of the waist (around the x-axis). ) Joints 12R, 1
2L, joints 14R, 14 in the same pitch direction (around the y axis)
L, joints 16R and 16L in the pitch direction of the knee, joints 18R and 18L in the pitch direction of the ankle, and joints 20R and 20L in the same roll direction. Foot 22R, 22L provided with an operation mechanism for operating the movable foot piece is attached, and a housing (upper body) 24 is provided at the top, and inside the operation, such as walking of the entire robot, is performed. A control unit 26 is stored as control means for controlling the control.

In the above description, the hip joint is the joint 10
R (L), 12R (L) and 14R (L), and the ankle joints are joints 18R (L) and 20R (L)
Therefore, it is constituted. Therefore, joint 18R (L),
The center of 20R (L) corresponds to the aforementioned ankle joint center position 23 (see FIG. 1). The thigh links 32R and 32L connect between the waist joint and the knee joint, and the thigh links 34R and 34L connect between the knee joint and the ankle joint.
Each is connected. Here, the movable leg 2 is given six degrees of freedom for each of the left and right feet, and by driving these 6 × 2 = 12 joints (axes) by an appropriate angle during walking, It is configured such that a desired movement can be given to the entire foot and the user can walk in a three-dimensional space arbitrarily. As described above, each of the above-mentioned joints is composed of an electric motor, and further includes a speed reducer for boosting the output of the joint. For details, refer to the application proposed by the present applicant (Japanese Patent Application No. -324218, JP-A-3-
No. 184,782), which is not the subject of the present invention per se, so that further description is omitted.

In the robot 1 shown in FIG. 2, a known six-axis force sensor 36 is provided at the ankle, and the six-axis force sensor 36 transmits x, y, and The force components Fx, Fy, Fz in the z direction and the moment components Mx, My, Mz around the directions are measured, and the presence or absence of landing on the foot and the magnitude and direction of the force applied to the support leg are detected. In addition, at the four corners of the foot 22R (L), for example, a capacitance type ground sensor 38 (omitted in FIG. 2) as ground detection means for detecting whether or not the foot touches the walking surface.
Is provided. When the six-axis force sensor 36 is used as the grounding detecting means, the grounding sensor 38 can be omitted. Further, the housing 24 includes an inclination sensor 40.
The tilt sensor 40 detects a tilt angle with respect to the z-axis in the xz plane and the yz plane, that is, a tilt angular velocity with respect to the direction of gravity. The electric motor of each joint is provided with a rotary encoder 46 (omitted in FIG. 1) for detecting the amount of rotation. Although not shown in FIG. 2, an origin switch 42 for correcting the output of the tilt sensor 40 is provided at an appropriate position of the robot 1.
And a limit switch 44 for failure countermeasures. These outputs are sent to the control unit 26 in the housing 24 described above.

FIG. 3 is a block diagram showing details of the control unit 26. This control unit 26 is constituted by a microcomputer. Here, the output of the inclination sensor 40 and the like is converted into a digital value by the A / D converter 50, and the output is transmitted to the RAM 54 via the bus 52. The output of the encoder 46 disposed adjacent to the electric motor of each joint is transmitted to the RAM 5 via the counter 56.
4 and the output of the ground sensor 38 and the like are input to the RAM 54 via the waveform shaping circuit 58.
First, second and third arithmetic units 60, 62 and 63 each comprising a CPU are provided in the control unit.
The arithmetic unit 60 reads a predetermined walking pattern such as a gravitational trajectory stored in the ROM 64, calculates a target joint angle, sends the calculated target joint angle to the RAM 54, and determines a walking state based on the read walking pattern. Is given to the third arithmetic unit 63. Further, the second arithmetic unit 62 reads out the target joint angle and the detected actual value from the RAM 54, calculates a control value necessary for driving each joint, and controls the D / A converter 66 and the servo amplifier 48. Output to the electric motor that drives each joint. Further, the third arithmetic unit 63 reads the signal indicating the presence / absence of grounding from the RAM 54, and actually detects the information on the walking state provided from the first arithmetic unit 60 and other walking states as necessary. Control device necessary for the operation of the movable foot piece of the foot is calculated according to the situation based on information from an apparatus (not shown) for example, for example, an image sensor for detecting stairs, etc. The signal is output via an / A converter 68 and a servo amplifier 70 to an actuator 74 of an operating mechanism 72 for operating the movable foot piece.

Next, the foot structure of the legged walking robot of the present invention will be described in detail with reference to FIG.

FIGS. 4 and 5 show an example of the structure of the foot 22R (22L) of the robot 1 shown in FIG. 2, that is, the foot structure of the first embodiment of the present invention. In addition, in each of the following drawings, the foot is symmetrical unless otherwise specified, so the symbols of L and R are omitted, and the foot is simply represented as foot 22. 4 and 5, the foot 22 includes a flat-shaped foot main body 100 attached to the lower end of the movable leg 2. The foot main body 100 is formed in a long plate shape when viewed two-dimensionally, and is attached to the movable leg 2 at the center position (more precisely,
The length from the vertical projection position of the ankle joint to the front end in the traveling direction of the robot (therefore, the length from the malleolus to the toe) is the length from the mounting center position to the rear end in the traveling direction (accordingly, from the ankle to the heel). (Length), the mounting position with respect to the movable leg 2 is determined. On the lower surface side of the four corners of the foot main body 100, flat movable foot pieces 102A, 102B, 102 each having an elliptical shape in plan view.
C, 102D, and these movable foot pieces 1
Each of 02A to 102D is rotatably supported by a vertical support shaft 104 in a horizontal plane (in a plane parallel to the ground plane). Each of the support shafts 104 is configured to be rotated about its axis by operating mechanisms 72 disposed at four corners on the upper surface side of the foot main body 100. As the operating mechanism 72, a geared motor using an electric motor as the actuator (reference numeral 74 in FIG. 3) in the illustrated example, or a mechanism using a pneumatic or hydraulic rotary actuator as the actuator can be applied.

Here, each support shaft 104 and each movable foot piece 10
The relative positional relationship with 2A to 102D is determined by each movable foot piece 10.
Each support shaft 104 is determined to be eccentric with respect to the center position between 2A and 102D. Therefore, as will be described later, the amount of protrusion of each of the movable foot pieces 102A to 102D outward from the foot main body 100 when viewed from above is changed when the movable foot pieces 102A to 102D are rotated.

At the four corners of the lower surface of the foot main body 100, cutout steps 106 for accommodating the movable foot pieces 102A to 102D are formed, and the movable foot pieces 102A to 102D are formed. An elastic material 10 such as rubber is
8 is stuck. In addition, in the actual foot, the lower edge of the elastic member 108, and further, the movable foot piece 10
The lower surface edges of 2A to 102D are often chamfered in an R shape or curved in an R shape, but R is not particularly shown here for simplification of the drawing. Also,
As shown in FIG. 3, when the presence or absence of the grounding state of the foot 22 is detected by using the grounding sensor 38, the grounding sensor 38 is usually provided on each of the movable foot pieces 102 </ b> A to 102 </ b> D. 4 and 5, the ground sensor is not shown for simplification of the drawings.

The function of the foot structure of the embodiment shown in FIGS. 4 and 5 will be described with reference to FIGS. In this embodiment, the movable foot pieces 102A to 102A
Only the lower surface of D, specifically, only the lower surface of each elastic member 108, is an effective contact surface 109 with respect to a walking surface such as a road surface during walking. 4 and 5 are states in which the movable foot pieces 102A to 102D are not swung out, and the state from the ankle joint center 23 to the rearmost end of the effective ground plane 109 in the robot traveling direction in this state. Projection distance A,
The projection distance B to the front end is shown in FIG. In this state, the ratio A / B of the distances A and B is about 0.79 in the examples of FIGS. When any one of the operating mechanisms 72 is operated from this state, the corresponding movable foot piece,
For example, 102 </ b> A rotates in a horizontal plane (and thus in a plane parallel to the effective ground plane) to rotate the notch step 106 of the foot body 100.
And the ratio A / B changes.
6 and 7 show a state in which the movable foot pieces 102A and 102B at the two corners on the front end side in the traveling direction of the robot are simultaneously swung obliquely forward. In this case, the ratio A / B becomes small, In the illustrated example, it is about 0.63. 8 and 9 show a state in which the movable foot pieces 102C and 102D at the two corners on the rear end side with respect to the traveling direction of the robot are simultaneously swung obliquely rearward. In this case, the ratio A / B Becomes larger, and A / B = 1 in the example shown. In this way, by appropriately rotating the movable foot pieces 102A to 102D, the ratio A / B of the distance A and the distance B can be changed appropriately.

FIG. 10 shows a flowchart for controlling the operation of the above-described foot structure according to the walking situation. In FIG. 10, the control is started, and in the first step 200, the ratio A / B at the foot is described.
It is determined whether or not it is predicted that a situation will occur in which walking is difficult in the initial state and the walking becomes difficult. Such a situation in which walking is difficult means, for example, ascending of stairs, descending of stairs, or increasing walking speed.
This determination may be made in the third arithmetic unit 63 shown in FIG. 3 based on information on a walking pattern to be walked from now on, or by detecting the presence of stairs by an image sensor (not shown). The determination may be made based on the obtained information, or the both may be used in combination. In step 200, when it is predicted that a situation that makes walking difficult will occur (YES),
Move to the next step 202. On the other hand, when it is not predicted (NO), the ratio A /
Without changing B, the initial state is maintained, and the control loop ends. That is, the actuator 74 of the operating mechanism 72 is not driven, and each of the movable foot pieces 102A to 102F of the foot is not driven.
102D is not activated.

In step 202, it is determined whether the foot contact surface is apart from the walking surface. This causes the actuator 74 of the foot operating mechanism 72 to be driven (therefore, the operation of each of the movable foot pieces 102A to 102D) is performed only in a state where the foot is away from the walking surface (in a state where the foot is not grounded). That's why. That is, when the movable foot pieces 102A to 102D are operated while the foot is in contact with the ground, a remarkably large load is applied to the actuator 74 of the operating mechanism 72, and the operation of the actuator 74 becomes difficult. This is because the actuator 74 may break down. In this step 202, the determination may be made based on the grounding detection signal from the grounding sensor 38 provided in advance on the foot or the signal from the six-axis force sensor 36. If it is determined in step 202 that the foot is not separated from the walking surface (NO),
Then, the process returns to step 202 after waiting for the foot to separate from the walking surface. On the other hand, if it is determined in step 202 that the foot is away from the walking surface (YES), the process proceeds to the next step 206.

In step 206, the ratio A
/ B to increase or decrease the value of / B
The actuator 74 of the operating mechanism 72 corresponding to one or more of 02A to 102D is driven. In this step 206, the ratio A is determined according to the type of situation predicted in step 200.
There is a case where the operation is performed in a direction to increase the value of / B, and a case where the operation is performed in a direction to decrease the value of the ratio A / B. Further, the amount of change in the value of the ratio A / B can be adjusted according to the degree of difficulty of the predicted situation. In addition, selection of increase or decrease of the value of these ratios A / B,
Normally, setting such as adjustment of the increase / decrease of the ratio A / B is normally performed in step 200 described above.

Here, since the actual bipedal walking type robot has two movable legs 2, step 2
02, 204, and 206 are left and right feet (22L, 22
R) are executed individually or sequentially. After the ratio A / B is increased or decreased in step 206 in this way, the walking operation proceeds while maintaining the state, and during that time, the next step 20
Move to 8. In step 208, it is determined whether or not the difficulty of walking has been resolved and the situation has returned to the initial state. That is, it is determined whether or not the difficulty of walking has been resolved during the walking after the end of step 206.
If it is determined in step 208 that the user has not returned from the situation where walking is difficult (NO),
The process proceeds to step S10, where the state is maintained, and the process returns to step 208 again after a predetermined time has elapsed. Step 208
If it is determined in step that the vehicle has returned from a situation where walking is difficult (YES), the process proceeds to step 212.

In step 212, the ratio A /
The value of the ratio A / B is decreased or increased so that the value of B returns to the initial value. That is, by operating the actuator 74 of the operating mechanism 72, the movable foot pieces 102A-1A
02D is returned to the initial position. Step 212
10 is executed, the actuator 74 of the actuating mechanism 72 is operated only when the foot is away from the walking surface, as shown in steps 202 and 204, as described above. When the robot is in contact with the walking surface, the actuator 74 is operated after waiting for the user to separate from the walking surface. In addition, this step 212 is actually executed individually or sequentially for each of the left and right foot (22R, 22L).

As described above, when there is a situation where it is predicted that walking is difficult, walking is performed by increasing or decreasing the value of the ratio A / B of the foot according to the situation. Thereby, the stability of walking can be ensured even under the above-mentioned situation.

Next, examples of the types of situations in which walking becomes difficult and the corresponding increase or decrease of the ratio A / B will be described with reference to FIGS.

FIG. 11 shows a situation when the robot 1 climbs the stairs 300. In many cases, the stairs 300 have projections 302 protruding in a convoluted manner at the upper edge of the stepped portion. If / B is small and the tip side of the foot 22 is long as indicated by the imaginary line in the figure, the tip of the foot 22 may interfere with the protrusion 302 and fall. Therefore, when such a situation is predicted, the ratio A / B of the distance A on the rear end side and the distance B on the front end side of the foot 22 is increased. Specifically, in the examples of FIGS. 4 to 9, the actuator 74 of the operating mechanism 72 may be operated so as to retract the movable foot pieces 102A and 102B on the front side in the traveling direction, for example. When climbing the stairs in this manner, it is preferable to set the ratio A / B to 1.0 or a value close to 1.0 (but not to exceed 1.0). Specifically, it is preferable to set so as to be in the range of 0.9 to 1.0.

FIG. 12 shows a situation when the robot 1 descends the stairs 300. When descending the stairs 300, a moment is applied to the robot 1 so as to fall forward (in the stairs descending direction) in the traveling direction, so that the distance A on the rear end side of the foot 22 and the distance B on the front end side are different. When the ratio A / B is large and the distal end side of the foot 22 is short, the robot 1 easily falls down. Therefore, when such a situation is predicted, the ratio A / B of the foot 22 is reduced. Specifically, in the examples of FIGS. 4 to 9, for example, the actuator 74 of the operating mechanism 72 may be operated so as to swing the movable foot pieces 102 </ b> A and 102 </ b> B on the front side in the traveling direction.

When the walking speed of the robot 1 is high, if the tip end of the foot 22 is long, interference is likely to occur, and the robot 1 tends to fall. Further, in this case, the tilt angle of the foot from swinging up of the foot 22 of the movable leg on the free leg side to landing is increased, and the operating moment of the movable leg is also increased. That is, in the walking of a general bipedal walking type robot, as shown in FIG. 13, when the foot 22 is separated from the walking surface, the foot 22 is first raised from the heel side and then moved in the air in the opposite direction.
It is normal to tilt and land again from the heel side, and then lower the toe side, so if the toe side is long, each tilt angle of the foot becomes large and its operating moment increases, especially the tendency It becomes remarkable when the walking speed is high, and it is easy to fall. Therefore, when walking at high speed, the ratio A / B of the distance A on the rear end side of the foot 22 and the distance B on the front end side is reduced, thereby reducing the risk of interference and the tilt angle of the foot. And thereby increase stability and reduce the risk of falling. In this case, when the walking speed is expected to exceed a predetermined speed, control may be performed so as to reduce the equivalent contact area of the foot 22. Of course, the equivalent contact area may be changed stepwise according to the walking speed.

Next, several other embodiments of the foot structure of the present invention, particularly, an embodiment in which a mechanical portion is modified are shown in FIG.
This will be described with reference to FIGS.

FIG. 14 shows operating foot pieces 102A to 102D.
FIG. 6 shows an example in which an operation mechanism 72 for activating the function is different from the embodiment of FIGS. In this case, the support shaft 104 of each movable foot piece 102A to 102D and each movable foot piece 10
Actuators 74 such as electric motors or fluid pressure rotary actuators provided corresponding to 2A to 102D
The worm gear 402 is interposed between the rotating shaft 404 and the worm gear 402 as a transmission mechanism.

In the example of FIG. 14, similarly to the examples of FIGS. 4 and 5, when the actuator 74 is driven, each of the movable foot pieces 102 A to 102
D is individually rotated in a plane parallel to the ground plane, so that the value of the ratio A / B can be changed. In this example, a worm gear 402 is interposed between the actuator 74 and each of the movable foot pieces 102A to 102D as a transmission mechanism. The reaction force is directly absorbed by the actuator 74.
In addition to this, it is possible to prevent the actuator 74 from significantly increasing the load or causing a failure.

FIG. 15 shows a further modification of the embodiment shown in FIG. 14 in which the two movable foot pieces 102A and 102B on the front side in the traveling direction of the robot are simultaneously operated, and the rear end of the robot in the traveling direction. Side two movable foot pieces 102C,
An example is shown in which the operating mechanism 72 is configured to simultaneously operate 102D. In FIG. 15, a common rotary drive type actuator 74A is provided for the two movable foot pieces 102A and 102B on the front side in the traveling direction of the robot, and the two movable foot pieces 102 on the rear side in the traveling direction of the robot.
A common rotary drive type actuator 74B is provided for C and 102D. Actuator 7
The rotational driving force of 4A is transmitted via a bevel gear mechanism 406A to two worm gears 402A, 402A,
402B, these worm gears 402A,
By 402B, the rotating foot pieces 102A and 102B are configured to be simultaneously rotated in opposite directions.
Similarly, the rotational driving force of the actuator 74B is also transmitted via the bevel gear mechanism 406B to the drive shaft 2 having a common axis on the driving side.
The worm gears 402C and 402D are provided so that the movable foot pieces 102C and 102D can be simultaneously rotated in opposite directions by the worm gears 402C and 402D.

In the example of FIG. 15, it is possible to reduce the value of the ratio A / B by simultaneously moving the movable foot pieces 102A and 102B on both sides forward in the traveling direction of the foot 22 forward in the traveling direction. Also, the movable foot pieces 102C and 102D can be simultaneously advanced rearward in the traveling direction on both sides of the foot 22 rearward in the traveling direction to increase the value of the ratio A / B.

In the example shown in FIG. 15, each of the actuators 74A and 74B and each of the movable foot pieces 102A to 102A are also provided.
Bevel gear mechanisms 406A and 406B and worm gears 402A to 402D are interposed between the 2D and the 2D as a transmission mechanism. Also in this case, the bending of each intermediate shaft can absorb the reaction force received from the walking surface to the ground surface. .

In each of the above examples, the movable foot piece 102A
The value of the ratio A / B is changed by rotating the movable foot pieces 102A to 102D in a horizontal plane (in a plane parallel to the ground contact surface).
Of course, the moving direction of D is not limited to this. 16 to 23 show an example in which the operating mechanism 72 is configured to change the ratio A / B by linearly moving the movable foot pieces 102A to 102D in a plane parallel to the ground contact surface.

First, in the embodiment shown in FIGS. 16 to 18, movable foot pieces 102 A to 102 D which are rectangular in plan view, for example, are formed on the four lower surfaces of the foot body 100.
Are arranged. These movable foot pieces 102A-10
On the lower surface of the 2D, an elastic material 108 is attached, respectively.
The lower surface of the elastic member 108 is an effective ground plane 109. The distal ends of the reciprocating axes 500A to 500D are fixed to the movable foot pieces 102A to 102D, respectively. To change the value of the ratio A / B. As the actuator 74 of the operating mechanism 72 for moving the respective reciprocating shafts 500A to 500D, a fluid pressure cylinder driven by fluid pressure such as air pressure or hydraulic pressure is used as shown in FIG.

FIG. 19 shows each of the movable foot pieces 102A to 102A.
A rotary drive type actuator such as an electric motor is used as the actuator 74 of the operating mechanism 72 for linearly moving the 2D forward and backward, and the rotary drive force of the actuator 74 is converted into a linear drive force by the screw mechanism 504 and transmitted. FIG. 18 shows a movable foot piece 102A corresponding to FIG. In FIG. 19, a female screw portion 508 formed on the advance / retreat shaft 500A is screwed to a screw shaft 506 rotated by the rotary drive type actuator 74. Therefore, the reciprocating shaft 500 is driven by the rotational driving force of the actuator 74.
A moves forward and backward, and accordingly, the movable foot piece 102A also moves forward and backward. Although not shown in FIG. 19, the operating mechanisms for the other movable foot pieces 102B to 102D are similarly configured.

FIG. 20 shows each of the movable foot pieces 102A to 102A.
As the actuator 74 of the operating mechanism 72 for linearly moving the 2D forward and backward, a rotary drive type actuator such as an electric motor is used as in the example of FIG. 19, and the rotary drive force of the actuator 74 is transmitted to the rack-pinion mechanism 5.
FIG. 18 shows an example in which the movable foot piece 102A is configured to be converted into a linear driving force for transmission. 20, a pinion 512 rotated by a rotary drive type actuator 74 is shown.
The rack 514 integral with the advance / retreat drive shaft 500A is meshed with the drive shaft 500A. Therefore, the rotational drive of the actuator 74 causes the advance / retreat shaft 500A to advance / retreat, and accordingly, the movable foot piece 102A also advances / retreats. The other movable foot pieces 102B to 102D are similarly configured.

FIGS. 21 to 23 show two movable foot pieces 102A and 102B on both sides in front of the robot in the traveling direction at the same time linearly, and two movable foot pieces on both sides behind in the traveling direction of the robot. An example in which pieces 102C and 102D are simultaneously linearly advanced and retracted is shown. 21 to 23
The movable foot piece 102 is provided on the lower surface side of the four sides of the foot body 100 having a rectangular shape in a plan view, corresponding to the left and right sides of one side of the front end side in the traveling direction of the robot.
A and 102B are provided, and movable foot pieces 102C and 102D are provided on the lower surface side at positions corresponding to the left and right sides of one side on the rear end side in the traveling direction of the robot. An elastic material 108 is adhered to the lower surface of each of the movable foot pieces 102A to 102D in the same manner as described above, and the lower surface is an effective ground surface 109. A convex or concave guided portion 531 is formed on both upper sides of the movable foot pieces 102A and 102B, and the guided portion 531 is slidable linearly on the foot main body 100 correspondingly. Guide portion 532 that engages with
Are formed. These guide portions 532 guide the movable foot pieces 102A, 102B in a direction parallel to the traveling direction of the robot (front-back direction), and also provide a reaction force from the walking surface applied to the movable foot pieces 102A, 102B when touching the ground. It is for receiving. On the other hand, the movable foot pieces 102C and 102D on the rear end side in the traveling direction of the robot are similarly configured to be guided and supported with respect to the foot body 100 along the traveling direction of the robot. Is omitted for convenience of the drawing.

Movable foot 1 on the front end side in the traveling direction of the robot
02A and 102B are operating mechanisms 7 having a single and common rotary drive type actuator 74F, for example, an electric motor.
The 2F is configured so that the robot is simultaneously moved linearly in the front-back direction of the traveling direction of the robot. That is, the rotational driving force of the actuator 74F is the bevel gear mechanism 5
34, and transmitted to the intermediate common rotation shaft 536, and the rotational force of the intermediate rotation shaft 536 is transmitted to the bevel gear mechanism 538A,
The rotation of the screw shafts 540A, 540B is transmitted to the screw shafts 540A, 540B via 538B, and the rotation of the screw shafts 540A, 540B is converted into linear motion by the female screw blocks 542A, 542B screwed to the screw shafts 540A, 540B. The movable foot pieces 102A, 102B fixed to the blocks 542A, 542B are linearly moved forward and backward. On the other hand, the movable foot pieces 102C and 102D on the rear end side in the traveling direction of the robot are simultaneously linearly moved in the front-rear direction in the traveling direction of the robot by a single and common rotary drive type actuator 74G, for example, an operating mechanism 72G having an electric motor. It is configured to be moved forward and backward. That is, the rotational driving force of the actuator 74G is transmitted to the intermediate common rotating shaft 536 via the bevel gear mechanism 534, and the rotating force of the intermediate rotating shaft 536 is further transmitted to the bevel gears 538C, 538.
The rotation of the screw shafts 540C and 540D is transmitted to the screw shafts 540C and 540D via the 38D.
The linear motion is converted by the female screw blocks 542C and 542D screwed to the screw shafts 540C and 540D, and the movable foot pieces 102C and 102D fixed to the female screw blocks 542C and 542D are linearly moved forward and backward.

In the embodiment shown in FIGS. 21 to 23, the movable foot pieces 102A, 102A on the front end side in the traveling direction of the robot are driven by driving the actuator 74F.
2B can be simultaneously moved forward and backward in the traveling direction of the robot to change the ratio A / B. Conversely, the value of the ratio A / B is also changed by driving the actuator 74G to simultaneously move the movable foot pieces 102C, 102D on the rear end side in the traveling direction of the robot backward and forward in the traveling direction of the robot. be able to.

Next, FIGS. 24 and 25 show that each of the movable foot pieces 102E to 102H is rotated about an axis horizontal to the foot main body 100 (an axis parallel to the ground contact surface). The foot structure of the embodiment in which the movable foot pieces 102E to 102H are raised and lowered with respect to the extension surface of the effective ground surface 109 of the foot body 100, thereby changing the value of the ratio A / B. Show.

24 and 25, the foot main body 100 is formed in a flat plate shape that is rectangular when viewed in plan. The front and rear ends of the lower surface of the foot main body 100 in the robot traveling direction are provided on the lower surface thereof. Each elastic material 108 is adhered, and the lower surface is an effective ground surface 109. A movable foot piece 102E is attached to the front end of the foot body 100 in the traveling direction so as to be rotatable about a horizontal support shaft 600 in a direction perpendicular to the traveling direction of the robot. On the other hand, a movable foot piece 102F is attached to the rear end of the foot body 100 in the traveling direction so as to be rotatable about a horizontal support shaft 602 perpendicular to the traveling direction of the robot. Further, on both left and right sides of the rear of the foot body 100 in the traveling direction, a support shaft 60 parallel and horizontal to the traveling direction of the robot is provided.
Movable foot pieces 102G and 102H are attached so as to be rotatable around 4,606. Elastic members 108 are also adhered to the back surfaces of these movable foot pieces 102E to 102H, respectively.

The movable foot piece 10 at the front end in the traveling direction of the robot
2E is configured to be turned (that is, raised and lowered) between an upright state and a horizontal state by an operating mechanism 72H including a rotary drive type actuator 74H such as an electric motor (including a geared motor). In particular,
The rotary drive type actuator 74 is attached to the foot main body 100.
H is fixed, and the screw shaft 608 having a vertical axis is rotated by the actuator 74H. And this screw shaft 60
A female screw block 610 is screwed into 8, and the female screw block 610 and the movable foot piece 102 </ b> E are connected by a link piece 612. Here, if the actuator 74H is driven, the screw shaft 608
As the female screw block 610 rotates, the female screw block 610 moves up and down, and the movable foot piece 102E is raised and lowered by the link piece 612. On the other hand, the movable foot piece 102 at the rear end in the traveling direction of the robot
F and movable foot pieces 10 on both sides at the rear end in the robot traveling direction
2G, 102H are those movable foot pieces 102F-10
Actuating mechanism 7 including a rotary drive type actuator 74I such as an electric motor (including a geared motor) common to 2H
By 2I, it is constituted so that it can be turned (that is, raised and lowered) between an upright state and a horizontal state. Specifically, the rotary drive type actuator 74I is fixed to the foot body 100, and the actuator 74I
I allows a screw shaft 614 having a vertical axis to be rotated. The screw shaft 614 is screwed with a female screw block 616, and the female screw block 616 and each movable foot piece 1
Link pieces 618 and 6 are provided between 02F and 102H, respectively.
20,622. Here, when the actuator 74I is driven, the female screw block 616 moves up and down with the rotation of the screw shaft 614, and the movable foot piece 102F is moved by the link pieces 618, 620, and 622.
〜１０102H are simultaneously undulated.

In this embodiment, by driving the actuator 74H, the movable foot piece 102E at the front end in the robot traveling direction is raised and lowered with respect to the extended surface of the effective ground plane 109 of the foot main body 100, whereby the robot is moved forward in the robot traveling direction. The value of the ratio A / B can be changed by enlarging / reducing the contact surface to the side. On the other hand, the actuator 74
By driving I, each of the movable foot pieces 102F to 102G on the rear side in the robot traveling direction is simultaneously raised and lowered with respect to the extension surface of the effective ground plane 109 of the foot body 100, and thereby the rear side in the robot traveling direction. Also, the value of the ratio A / B can be changed by digitally reducing and enlarging the ground contact surface in both side directions of the rear end.

[0045] In the invention of claim 1, at least a
One of the co-when a movable leg, the foot structure of the movable legs by providing a foot walking freely and the legged walking robot to the tip, the said foot and foot body the foot body Actuator
Is it a movable foot piece that is mounted so that it can move relatively through the structure
And the movable foot via the operating mechanism.
Pieces, ankle joint center position or Lalo box <br/> preparative traveling direction distance A and the ankle joint center position <br/> or Lalo bot traveling direction frontmost end of the last Tanma near the foot body the ratio of the distance B of up to a /
Since B is configured as to move in a direction that changes the status of the robot walking, for example, increase the stairs, descending, or in accordance with the walking conditions such as walking speed, so as to enhance the most stability of the walking, the ratio The value of A / B can be changed, and thus the stability of walking can be dramatically improved even in various situations where walking becomes difficult.

[0046] The operating state In the invention of claim 2, which includes a ground detection means for detecting the presence or absence of the condition being grounded to the foot Xiaoping walking surface, not the foot Xiaoping ground Since the mechanism is configured to operate, it is possible to effectively prevent a remarkable large load from being applied to the operating mechanism or a failure of the operating mechanism due to a reaction force from the walking surface when the foot lands.

[0047] In the invention of claim 3, wherein in response to information of the control means for controlling the walking of the robot, the direction of the walking speed is increased the ratio A / B when exceeding a predetermined value Since the operation mechanism is configured to operate, when walking at high speed, it is possible to reduce the risk that the foot of the free leg interferes, and to reduce the tilt angle of the foot of the free leg to reduce The moment can be reduced, so that the stability during high-speed walking can be increased, and the occurrence of a situation where the robot falls down can be effectively prevented.

[0048] In the invention of claim 4, in accordance with the information of the control means for controlling the walking of the robot, the operation of the actuating mechanism in the direction to increase the ratio A / B in increasing walking stairs Because of such a configuration, even when climbing a staircase in which a stair-like protrusion exists at the upper end of the step portion of the staircase, it is possible to prevent the toe side portion of the foot from interfering with the protrusion, particularly As in the invention of claim 5, when walking up the stairs, the ratio A / B is 1.0 or more.
When the operating mechanism is operated so as to be within the range near the toe, it is possible to reliably prevent a situation in which the tip of the foot on the toe side interferes with the protrusion and falls down.

[0049] In the invention of claim 6, operation of the actuating mechanism in response to information of the control means for controlling the walking of the robot, the direction of reducing the ratio A / B in the descending walking stairs With such a configuration, it is possible to increase the stability of the robot when descending the stairs and prevent the robot from falling down.

[0050] In the invention of claim 7, with the interposition of the transmission mechanism between the actuator and the movable foot piece of the actuating mechanism, said transmission mechanism, the foot from the walking surface during ground of the foot because you configure the reaction force applied to the effective ground plane of the flat so as not to transmit directly to the actuator, it is possible to effectively prevent the actuator of the actuating mechanism by a reaction force or failure.

[0051] In the invention of claim 8, as the movable foot piece has linearly slidably mounted with respect to the foot main body in the effective ground plane and parallel to the plane structure
Because it forms, by changing the value of linearly sliding the movable foot piece said ratio A / B depending on the situation, it is possible to increase the stability of the robot walking, also in this case the ratio Since the value of A / B can be changed in an analog manner, the ratio A / B can be set to an optimal value according to the situation.

[0052] In the invention of claim 9, wherein the movable foot piece, wherein so as to be rotatable about the axis line perpendicular to the effective ground plane in the effective ground plane and the plane parallel to because it configured as that attached to the foot body,
By changing the ratio A / B by rotating the movable foot piece according to the situation, the stability of the robot can be increased, and also in this case, as in the case of the invention of claim 8 ,
The ratio A / B can be set to an optimal value according to the situation.

[0053] In the invention of claim 10, wherein the movable foot piece, undulating with respect to the extension plane of the effective ground contact surface of the foot body
Possible because you as configured is attached to the rotation available-around the effective ground plane and parallel to the axis so that the value of the ratio A / B by undulating movable foot piece according to the situation By changing, the stability of walking of the robot can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram schematically showing the vicinity of a foot of a legged walking robot to explain the operation of the present invention.

FIG. 2 is a schematic diagram generally showing an example of a control device for a legged walking robot according to the present invention.

FIG. 3 is an explanatory block diagram of a control unit shown in FIG. 2;

FIG. 4 is a plan view showing an example in which a movable foot piece is rotated in a horizontal plane as a foot structure according to an embodiment of the present invention.

5 is a vertical sectional front view taken along line VV of the foot structure shown in FIG. 4;

6 is a plan view showing an example of an operation state of the foot structure shown in FIG.

FIG. 7 is a longitudinal sectional view taken along line VII-VII of FIG. 6;

FIG. 8 is a plan view showing another example of the operation state of the foot structure shown in FIG. 4;

9 is a longitudinal sectional view taken along line IX-IX in FIG.

FIG. 10 is a flowchart showing an example of a control flow for operation of the foot structure of the present invention.

FIG. 11 is a schematic illustration showing a situation in which a two-legged robot to which the foot structure of the present invention is applied rises up stairs.

FIG. 12 is a schematic diagram showing a situation in which a two-legged robot to which the foot structure of the present invention is applied goes down stairs.

FIG. 13 is a schematic diagram showing a state of a two-legged robot at the time of high-speed walking with respect to a conventional technique.

14 is a plan view showing an embodiment in which the operation mechanism of the foot structure shown in FIG. 4 is changed.

FIG. 15 is a plan view showing another embodiment of the foot structure shown in FIG. 4 in which the operation mechanism is changed.

FIG. 16 is a plan view showing an example in which a movable foot piece is linearly moved in a horizontal plane as a foot structure according to an embodiment of the present invention.

FIG. 17 is a front view of the foot structure shown in FIG. 16;

FIG. 18 is an enlarged sectional view taken along line XVIII-XVIII in FIG.

19 is a cross-sectional view showing an example of the foot structure shown in FIG. 16 in which the operation mechanism is changed, at the same position as in FIG. 18;

FIG. 20 is a cross-sectional view showing another example of the foot structure shown in FIG. 16 in which the operation mechanism is changed, at the same position as in FIG. 18;

FIG. 21 is a plan view showing an example of a foot structure according to an embodiment of the present invention, in which a movable foot piece is linearly moved in the front-rear direction in the traveling direction of the robot.

FIG. 22 is a front view of the foot structure of FIG. 21.

FIG. 23 is a longitudinal sectional view taken along line XXIII-XXIII in FIG. 21.

FIG. 24 is a partially cutaway perspective view showing an example in which a movable foot piece is raised and lowered as the foot structure of one embodiment of the present invention.

FIG. 25 is a longitudinal sectional view taken along line XXV-XXV in FIG. 24.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Robot 2 Movable leg 22 Foot 23 Ankle joint center 72 Actuation mechanism 74, 74A, 74B, 74F, 74G, 74H, 74
I Actuator 100 Foot main body 102A, 102B, 102C, 102D, 102E,
102F, 102G, 102H Movable foot piece 109 Effective ground surface

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor ▲ Taka ▼ Hashiaki 1-4-1 Chuo, Wako-shi, Saitama Prefecture Inside Honda R & D Co., Ltd. (72) Takashi Matsumoto 1-4-4 Chuo, Wako-shi, Saitama No. 1 Inside Honda R & D Co., Ltd. (72) Inventor Akira Takeno 1-4-1 Chuo, Wako-shi, Saitama Pref. Inside Honda R & D Co., Ltd. (56) References JP-A-3-1844781 (JP, A) (58 ) Surveyed field (Int.Cl. ⁷ , DB name) B25J 5/00

Claims (10)

(57) [Claims] To 1. A co <br/> and comprises at least one movable leg, the foot structure of the movable leg legged walking robot which is freely walking provided foot to the tip of the foot The foot is connected to the foot body and the foot body via an operating mechanism.
Consists of a movable foot piece that is mounted so as to be relatively movable
Along with the movable foot piece via the operating mechanism,
The ratio of the distance B to the the distance A ankle joint center position or Lalo box <br/> preparative traveling direction frontmost end of the ankle joint center position or Lalo bot traveling direction last Tanma near the foot body foot legged walking robot, characterized by being configured so as to move in the direction in which the a / B varies flat structure. 2. A including a ground detection means for detecting the presence or absence of the condition being grounded to the foot Xiaoping walking surface, that operating the actuation mechanism and do not have the foot Xiaoping ground
The foot structure of the legged walking robot according to claim 1. 3. Depending on the information of the control means for controlling the walking of the robot, characterized by operating the actuating mechanism walking speed to the ratio A / B be increased direction when exceeding a predetermined value The foot structure of the legged walking robot according to claim 1. 4. The method according to claim 1, wherein the ratio A /
That operates the actuating mechanism in the direction to increase the B
The foot structure of the legged walking robot according to claim 1. 5. When walking up stairs, the ratio A /
The foot structure of a legged walking robot according to claim 4, wherein the operating mechanism is operated so that B is set to 1.0 or a range in the vicinity thereof . 6. When the robot walks down stairs according to information of control means for controlling the walking of the robot, the ratio A /
That operates the actuating mechanism in the direction to reduce the B
The foot structure of the legged walking robot according to claim 1. 7. with interposing a transmission mechanism between the actuator and the movable foot piece of the actuating mechanism, wherein the heat transfer <br/> us mechanism, effective of the foot from the walking surface during ground of the foot The foot structure of a legged walking robot according to claim 1, wherein a reaction force applied to a ground contact surface is not directly transmitted to the actuator. Wherein said movable foot piece, according to claim 1, characterized in that said are linearly slidably mounted with respect to the foot main body in the effective ground plane and the plane parallel to Foot structure of a legged walking robot. Wherein said movable foot piece is attached to the foot body so as to be pivotable about an axis line perpendicular to the effective ground plane in the effective ground plane and the plane parallel to The foot structure of a legged walking robot according to claim 1, wherein: 10. The movable foot piece is provided with the foot main body.
Legged walking robot according to claim 1, characterized in that attached to the rotating available-around the effective ground plane and parallel to the axis so as to allow relief with respect to the extended surface of the effective ground plane Foot structure.