JP3026274B2 - 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. That is, it is relatively easy to maintain stability when walking at low speed on a horizontal plane, but when climbing up and down stairs or walking on a slope, or when there is an obstacle on the walking surface, Furthermore, when the walking speed is high, walking with two feet tends to be unstable. In addition, walking with two feet may be difficult due to external environmental factors such as vibration and wind caused by an earthquake.

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. In addition, when straddling an obstacle such as a protrusion existing on a walking surface, if the foot is large, the tip or the rear end of the foot may interfere with the obstacle and fall. Further, even when the walking speed is high, if the foot is large, the foot is likely to interfere and fall easily. In addition, various situations are conceivable, but in any case, simply designing a large foot is not a fundamental solution for increasing stability during walking.

The present invention has been made in view of the above circumstances, and has a foot structure capable of always maintaining walking stability even when a walking surface condition, a walking speed, or a surrounding condition changes. The basic purpose is to provide.

[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 in the figure, in a foot structure of a legged walking robot having a plurality of movable legs and providing a foot at the tip of each movable leg to be able to walk freely, it is connected to each movable leg. At least one movable foot piece is attached to each of the foot main bodies, the movable foot piece being movable in a direction in which an area surrounded by an envelope connecting the outer edge of the effective ground contact surface to the walking surface can be enlarged and reduced. An operation mechanism for moving in the direction is provided on the foot main body.

[0007]

In the foot structure of the present invention, the area surrounded by the envelope connecting the outer edge of the effective ground contact surface to the walking surface can be enlarged or reduced by operating the movable foot piece by the operating mechanism. . Here, when the robot walks, it functions as a fulcrum with respect to the walking surface so that the robot does not fall down. The outermost edge of the contact surface of each foot, particularly the position of the mounting axis of the movable leg (the vertical position of the ankle joint). (Projection position), the size (area) of the region surrounded by the envelope connecting the outer edges of the effective ground plane as described above is to support the movable leg with respect to the walking surface. In this specification, this area will be referred to as an equivalent ground area in the following description.

As described above, in the structure of the present invention, since the size of the equivalent grounding area can be enlarged or reduced, for example, the stairs can be raised or lowered, the existence of obstacles on the walking surface, the inclination of the walking surface, The size of the equivalent contact area can be selected so that the stability of walking can be maximized according to the walking conditions such as the walking speed and environmental factors such as earthquakes.

[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. 1 is an explanatory skeleton diagram schematically showing the entirety 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. The hip joint and the knee joint are connected by thigh links 32R and 32L, and the knee joint and the ankle joint are connected by crus links 34R and 34L. 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-3-1847
No. 82) and the like are not themselves the subject of the present invention, and therefore, further description will be omitted.

In the robot 1 shown in FIG. 1, 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. Also, at the four corners of the foot 22R (L), for example, a capacitance type ground sensor 38 (omitted in FIG. 1) as ground detection means for detecting the presence or absence of the ground on the walking surface of the foot.
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. 1, 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. 2 is a block diagram showing details of the control unit 26. The 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. Based on information from an image sensor (not shown), for example, an image sensor for detecting an obstacle or stairs, and an earthquake detector (not shown) provided inside or outside the robot. The control value required for the operation of the movable foot piece is calculated in accordance with the above situation, and the calculated value is supplied to the actuator 74 of the operating mechanism 72 for operating the movable foot piece via the D / A converter 68 and the servo amplifier 70. Output.

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

FIGS. 3 and 4 show an example of the structure of the foot 22R (22L) of the robot 1 shown in FIG. 1, 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. 3 and 4, the foot 22 has a flat foot 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 ankle joint's vertical projection position O to the front end of the robot in the traveling direction (and therefore the length from the ankle to the toe) is
So as to be longer than the length from the mounting center position O to the rear end in the traveling direction (therefore, the length from the ankle to the heel),
The mounting position with respect to the movable leg 2 is determined. On the lower surface of the four corners of the foot body 100, flat movable foot pieces 102A, 102B, 10
2C and 102D are provided, and these movable foot pieces 102A to 102D are rotatably supported in a horizontal plane (in a plane parallel to the ground plane) by vertical support shafts 104, respectively. Each support shaft 104 is connected to the foot body 100, respectively.
It is configured to be rotated about an axis by operating mechanisms 72 disposed at four corners on the upper surface side of the. As the operating mechanism 72, in the illustrated example, a geared motor using an electric motor as the actuator (reference numeral 74 in FIG. 2), or a mechanism using a pneumatic or hydraulic rotary actuator as the actuator can be used.

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. In addition, as shown in FIG. 2, when the presence or absence of the grounding state of the foot 22 is detected 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. 3 and 4, the ground sensor is not shown for simplification of the drawings.

The function of the foot structure of the embodiment shown in FIGS. 3 and 4 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. Envelopes connecting the outer edges of these effective ground planes 109 are shown by two-dot chain lines 110 in FIGS. 3 and 5 to 7. The area surrounded by the envelope 110 is the above-described equivalent ground area. The state shown in FIGS. 3 and 4 is a state in which the area of the equivalent grounding region is the smallest, and when any one of the operating mechanisms 72 is operated from this state, the corresponding movable foot piece, for example, 102A is placed on the horizontal plane. (In a plane parallel to the effective ground plane) to rotate the foot body 100.
The movable foot piece 102A protrudes from the notch stepped portion 106, and the amount of protrusion of the movable foot piece 102A with respect to the foot main body 100 increases, and the equivalent ground contact area is enlarged. FIG. 5 shows movable foot pieces 102A and 102 at two corners on the front end side in the traveling direction of the robot.
FIG. 6 shows 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 simultaneously inclined obliquely forward. FIG. 7 shows all the movable foot pieces 102A.
10 to 102D are simultaneously drawn out.

In this manner, the movable foot pieces 102A-1
By turning 02D appropriately, the equivalent ground area can be enlarged or reduced. Moreover, in this embodiment, since the operating mechanism 72 is provided in each of the movable foot pieces 102A to 102D, each of the movable foot pieces 102A to 102D is provided.
To 102D can be individually rotated. Therefore, for example, as shown in FIG. 5, only the movable foot pieces 102A and 102B on the front end side in the traveling direction of the robot are swung diagonally forward, and the equivalent ground contact area is enlarged only forward in the traveling direction. Conversely, as shown in FIG. 6, only the movable foot pieces 102C and 102D on the rear side in the traveling direction are swung obliquely rearward, and a state where the equivalent grounding area is enlarged only on the rear side in the traveling direction can be created. .

FIG. 8 shows a flowchart for controlling the operation of the above-described foot structure according to the walking situation. In FIG. 8, in the first step 200 after starting the control, it is predicted whether or not a situation will occur in which walking is performed with the equivalent footprint area of the foot in the initial state, and the walking becomes difficult. Is determined. The situation in which walking is difficult in this way means, for example, ascending of stairs, descending of stairs, presence of obstacles on the walking surface, slopes, environmental factors such as occurrence of earthquakes and strong winds, and increase in walking speed. I do. This determination may be made in the third arithmetic unit 63 shown in FIG. 2 based on information on a walking pattern to be walked from now on, or an image sensor (not shown) may be used to determine the presence of stairs or an obstacle. The determination may be made based on information obtained by actually detecting or detecting the occurrence of an earthquake by the earthquake detecting means, or may be performed by using both of them. If it is predicted in step 200 that a situation that makes walking difficult will occur (YES), the process proceeds to the next step 202.
On the other hand, if it is not predicted (NO), as shown in step 214, the control loop is terminated without changing the area of the equivalent ground area, keeping the initial state. That is, the actuator 74 of the operating mechanism 72 is not driven, and the movable foot pieces 102A to 102D of the foot are not operated.

In step 202, it is determined whether or not 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, each of the movable foot pieces 10 is enlarged or reduced in order to enlarge or reduce the equivalent ground contact area.
The actuator 74 of the operating mechanism 72 corresponding to one or more of 2A to 102D is driven. In step 206, depending on the type of situation predicted in step 200, the operation may be performed in a direction in which the equivalent ground region is enlarged, or may be performed in a direction in which the equivalent ground region is reduced. .
Further, it is possible to select a direction in which the equivalent ground contact area is enlarged or reduced (for example, forward or backward in the traveling direction) according to the type of the predicted situation. Moreover,
The change amount (enlargement amount or reduction amount) of the equivalent contact area can be adjusted according to the degree of difficulty of the predicted situation. The selection of the enlargement or reduction of the equivalent ground area, the selection of the direction of the enlargement / reduction, and the adjustment of the amount of the enlargement / reduction are usually 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 foot equivalent ground contact area is enlarged or reduced in step 206 in this way, the walking operation proceeds while maintaining that state, and during that time, the process proceeds to the next step 208. 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 shifts to step 210 to maintain the state as it is, and returns to step 208 again after a predetermined time has elapsed. On the other hand, if it is determined in step 208 that the user has returned from the situation where walking is difficult, the process proceeds to step 212.

In step 212, the equivalent ground contact area is reduced or enlarged so that the area of the foot equivalent ground contact area returns to the initial area. That is, the operating mechanism 72
Of the movable foot piece 102 by operating the actuator 74
A-102D is returned to the initial position. Although not shown in FIG. 8, when executing step 212, the actuator 74 of the operating mechanism 72 is operated only when the foot is away from the walking surface as in steps 202 and 204 already described. When the foot is in contact with the walking surface, the actuator 74 is operated after the foot is separated from the walking surface. Note that this step 212 is also performed for each of the left and right feet (22R, 22L).
They will be executed individually or sequentially.

As described above, when there is a situation in which it is predicted that walking is difficult, walking is performed by expanding or reducing the equivalent footprint area of the foot according to the situation. Under such circumstances, walking stability can be ensured.

Next, examples of the types of situations in which walking becomes difficult and the corresponding expansion or reduction of the equivalent contact area will be described with reference to FIGS.

FIG. 9 shows a situation when the robot 1 climbs the stairs 300. In many cases, the stairs 300 have projections 302 protruding in a ridge-like manner at the upper edge of the step portion. In this case, if the foot 22 is wide as shown by the imaginary line in the figure, the tip of the foot 22 is projected. There is a risk of falling over due to interference with the unit 302. Therefore, when such a situation is predicted, the equivalent contact area of the foot 22 is reduced. In this case, there is a possibility that the projection 302 may interfere with the foot 2.
2, the equivalent ground contact area may be reduced on the front end side of the foot 22. In other words, if the actuator 74 of the operating mechanism 72 is operated to reduce the distance from the attachment position of the foot 22 to the movable leg 2 (the vertical projection position of the ankle joint of the movable leg 2) to the tip of the toe. good.

FIG. 10 shows a situation when the robot 1 descends the stairs 300. When descending the stairs 300, a moment acts on the robot 1 to fall forward (in the stairs descending direction) in the traveling direction. Therefore, if the area of the equivalent contact area of the foot 22 is small, the robot 1 easily falls down. Become. Therefore, when such a situation is expected, the equivalent contact area of the foot 22 is expanded. In this case, the longer the distance from the front end of the foot 22 in the traveling direction to the mounting position of the movable leg 2 (the distance from the malleolus to the toe), the more it is possible to prevent the user from falling down forward. What is necessary is just to enlarge the equivalent ground area on the front end side. In other words, the actuator 74 of the operating mechanism 72 extends the distance from the mounting position of the foot 22 to the movable leg 2 (the vertical projection position of the ankle joint of the movable leg 2) to the front end (toe) of the equivalent ground contact area. Should be operated.

FIG. 11 shows a situation where an obstacle, for example, a projection 304 is present on the walking surface 306. In this case, if the equivalent contact area of the foot 22 is large, the movable leg 2 on the free leg side
The tip of the foot 22 interferes with the obstacle 304 when swinging up, and when the movable leg 2 on the free leg side swings down,
The rear end of the robot 2 may interfere with the obstacle 304 and the robot 1 may fall down. Therefore, in this case, the foot 22
By reducing the equivalent grounding area, the risk of falling as described above can be avoided.

Further, although not particularly shown, when the walking surface is a slope, the robot 1 falls down on the slope either when ascending the slope, descending the slope, or crossing the slope. Because it ’s easier
In this case, the equivalent ground area of the foot 22 is enlarged.

When the walking speed of the robot 1 is high, if the area of the foot 22 is large, the foot on the free leg side during walking tends to interfere, and the robot easily falls. Therefore, when walking at high speed, the equivalent contact area of the foot 22 can be reduced, thereby reducing 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.

When it is predicted that the walking of the robot 1 becomes unstable due to external environmental factors such as when an earthquake is detected or when the wind speed is high outdoors, the equivalent contact area of the foot 22 is set. Enlarge to ensure walking stability. When it is predicted that the walking becomes unstable due to external environmental factors, it is desirable to control so as to reduce the walking speed while expanding the equivalent ground contact area.

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. 12 shows the operating foot pieces 102A to 102D.
FIG. 5 shows an example in which an operation mechanism 72 for activating the operation 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. 12, similarly to the examples of FIGS. 3 and 4, when the actuator 74 is driven, the movable foot pieces 102 A to 102
D is individually rotated in a plane parallel to the ground plane, so that the equivalent ground area can be scaled in any direction. 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 applied to the actuator 74 to prevent the actuator 74 from significantly increasing the load or causing a failure.

FIG. 13 shows a further modification of the embodiment shown in FIG. 12, in which the two movable foot pieces 102A, 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. 13, a common rotary drive type actuator 74A is used for two movable foot pieces 102A and 102B on the front side in the traveling direction of the robot, and 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. 13, the equivalent ground contact area in the forward direction of the foot 22 can be simultaneously enlarged and reduced on both sides of the forward direction of the foot 22. Also, at the same time, the equivalent ground area can be enlarged and reduced backward in the traveling direction.

FIG. 14 shows all the movable foot pieces 102A.
10 shows an example in which the operating mechanism 72 is configured to simultaneously operate. In this case, all the movable foot pieces 102A ~
One rotational drive type actuator 7 for 102D
4E, two bevel gear mechanisms 406A and 406B and four worm gears 402A to 404B, similar to the example shown in FIG.
The movable foot pieces 102A to 102D are simultaneously provided to the movable foot pieces 102A to 102D via 02D, and the movable foot pieces 102A to 102D are simultaneously rotated. Therefore, in this example, the equivalent ground area expands and contracts in all directions at once.

In the examples shown in FIGS. 13 and 14,
Bevel gear mechanism 406A, 4 between each actuator 74A-74D; 74E and each movable foot piece 102A-102D.
06B and the worm gears 402A to 402D intervene as a transmission mechanism, and in this case also, the bending of the respective intermediate shafts can absorb the reaction force received from the walking surface to the ground contact surface.

FIG. 15 shows each of the movable foot pieces 102A to 102A.
Another example for simultaneously and simultaneously operating 2D is shown. FIG.
5, the support shaft 1 of each movable foot piece 102A to 102D
04 is provided with a pulley 410, and as the actuator 74 of the operating mechanism 72, a rotary drive type is provided in the same manner as described above. A pulley 412 is also provided on the rotation shaft of the actuator 74,
Four pulleys 41 on each movable foot piece 102A to 102D side
A common endless annular belt 414 is wound around the pulley 412 on the side of the actuator 74 and the actuator 74. Therefore, by driving the actuator 74, the belt 41
4 so that each pulley 410, 412
To rotate the movable foot pieces 102A to 102D simultaneously and simultaneously. That is, the equivalent ground area can be simultaneously enlarged and reduced in all directions. In this case, a sprocket may be used instead of the pulleys 410 and 412, and a chain may be used instead of the belt 414.

In each of the above examples, the movable foot piece 102A
Although the equivalent ground contact area is configured to be enlarged or reduced by rotating the movable foot pieces 102A to 102D in a horizontal plane (in a plane parallel to the effective ground contact plane), the movable foot pieces 102A to 102A-1
Of course, the moving direction of 02D is not limited to this. 16 to 26 show movable foot pieces 102A to 102A.
An example is shown in which D is linearly moved in a plane parallel to the effective ground plane to expand and contract the equivalent ground area.

First, in the embodiment shown in FIG. 16 to FIG. 18, movable foot pieces 102A to 102D which are rectangular,
Are arranged. These movable foot pieces 102A-10
Elastic members 108 are adhered to the lower surfaces of the 2D, respectively, and the lower surfaces of the elastic members 108 serve as effective ground planes 109. The distal ends of the reciprocating axes 500A to 500D are fixed to the movable foot pieces 102A to 102D, respectively. And the above-mentioned equivalent ground area is enlarged / reduced. As the actuator 74 of the operating mechanism 72 for moving the respective reciprocating shafts 500A to 500D, FIG.
As shown in FIG. 8, a fluid pressure cylinder driven by fluid pressure such as air pressure or hydraulic pressure is used.

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.

FIG. 21 shows a movable foot piece 102 as described above.
In a foot structure of a type in which the equivalent ground contact area is enlarged and reduced by linearly moving A to 102D, in particular, the movable foot pieces 102A to 102D are simultaneously moved using a common and single actuator 74. An example is shown below. In this example, as the actuator 74, the drive side (fluid pressure addition side) of the four hydraulic cylinders 516A to 516D
Is used. Other configurations are the same as those in the examples shown in FIGS. In this case, the fluid pressure is injected to the drive side of the actuator 74 or discharged only from the drive side, and each of the reciprocating shafts 5
00A to 500D at once, and each movable foot piece 10
By moving the 2A to 102D simultaneously, the equivalent ground area can be simultaneously expanded or reduced in all directions.

FIG. 22 shows each movable foot piece 10 as described above.
Another example is shown in which 2A to 102D are simultaneously moved linearly forward and backward. In FIG. 22, the operating mechanism 72
A rotary drive type such as an electric motor (including a geared motor) is used as the actuator 74, and a disk-shaped rotary body 522 is fixed to a rotary drive shaft 520 of the rotary drive type actuator 74. Each movable foot piece 102A is provided in a portion near the outer periphery of the rotating body 522.
The reciprocating shafts 500A to 500D of to 102D are connected via links 522A to 522D, respectively. Guides 524A to 524D are provided for each of the reciprocating shafts 500A to 500D to guide the linear behavior in the axial direction. Also in such an embodiment, the rotational driving force of the rotational drive type actuator 74 is controlled by the link 522A.
The driving force is converted into a linear driving force by a link mechanism composed of the moving foot pieces 522D and 522D, and the movable foot pieces 102A to 102D move forward and backward at the same time via the moving axes 500A to 500D.

FIG. 23 shows movable foot pieces 102A-102.
In a foot structure in which D moves linearly,
An example is shown in which a pair of movable foot pieces located on the symmetric side in the 0 ° direction are simultaneously moved by using a rack-pinion mechanism. In FIG. 23, the movable foot pieces 102A,
A rotary drive type actuator such as an electric motor is provided as a common actuator 74 for 2C, and a pinion 526 is provided on a rotary drive shaft 524 of the actuator 74. The pinion 526 includes a movable foot piece. The rack 527A integrated with the reciprocating shaft 500A of 102A and the reciprocating shaft 50 of the movable foot piece 102C.
The rack 527C integrated with OC is engaged.
And the reciprocating axes 500A, 500C, racks 527A, 5
Guide 5 for 27C
28, 530 are provided. The operating mechanisms for the remaining two movable foot pieces 102B and 102D are configured in the same manner as described above, but are omitted for convenience of the drawing. FIG. 2
In the example of No. 3, by operating the rotary drive type actuator 74, the movable foot pieces 102A, 102A,
2C can be moved forward and backward at the same time, and the remaining movable foot pieces 102B and 102D can be moved forward and backward at the same time by operating another rotary drive type actuator (not shown).

FIGS. 24 to 26 show two movable foot pieces 102A and 102B on both sides forward in the traveling direction of the robot in a straight line at the same time, and two movable foot pieces on both sides backward in the traveling direction of the robot. An example in which pieces 102C and 102D are simultaneously linearly advanced and retracted is shown. 24 to 26
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.

The movable foot 1 at 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. 24 to 26, 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, and the equivalent contact area can be enlarged and reduced only forward in the traveling direction of the robot. Conversely, by driving the actuator 74G, the movable foot pieces 102C and 102D at the rear end side in the traveling direction of the robot are simultaneously advanced and retracted backward in the traveling direction of the robot, and the equivalent ground contact area is expanded only in the backward direction of the robot traveling. Can be reduced.

Next, FIGS. 27 and 28 show that each of the movable foot pieces 102E to 102H is rotated about a horizontal axis (an axis parallel to the ground contact surface) with respect to the foot main body 100 so that they can be rotated. 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 expanding and reducing the equivalent ground area is shown.

27 and 28, 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. Foot body 10
A movable foot 102E is attached to the front end of the traveling direction 0 so as to be orthogonal to the traveling direction of the robot and rotatable about a horizontal support shaft 600. 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.
Furthermore, on the left and right sides at the rear of the foot body 100 in the traveling direction,
A support shaft 604, 6 that is parallel and horizontal to the traveling direction of the robot
Movable foot piece 10 so as to be rotatable about 06.
2G and 102H are attached. The elastic members 108 are respectively provided on the back surfaces of these movable foot pieces 102E to 102H.
Is affixed.

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, the movable foot piece 102E at the front end in the robot traveling direction is raised and lowered with respect to the extension surface of the effective installation surface of the foot main body 100 by driving the actuator 74H. Thus, the equivalent ground area can be digitally reduced and expanded. On the other hand, by driving the actuator 74I, each movable foot piece 102F on the rear side in the robot traveling direction is
-102G is simultaneously raised and lowered with respect to the extension surface of the effective installation surface of the foot body 100, thereby digitally reducing / enlarging the equivalent ground contact area in the rear direction and the rear end both sides with respect to the robot traveling direction. Can be.

As described above, in each of the embodiments shown in FIGS. 3 to 7 and FIGS. 12 to 28, in the legged walking robot having a plurality of movable legs, one leg of the movable leg is used. He explained only Tada. Here, basically, the foot of all the movable legs may have the same shape (the same structure) or a symmetric shape (a symmetric structure). When considered at the same time, the direction in which the equivalent ground contact area of each foot is to be enlarged or reduced (the direction in which each movable foot piece can move) is preferably determined according to the positional relationship between the feet. That is, claim 1
As described in 2, when all the movable legs are in a stationary upright state and each foot is aligned in the front-rear direction and left-right direction of the robot, the entire envelope of the equivalent ground contact area of each foot is enclosed. The equivalent grounding area of each foot is expanded in the direction of expanding and reducing the area (hereinafter referred to as a comprehensive grounding area)
It is preferable to provide the movable foot piece so as to reduce the size. Hereinafter, a specific example will be described with reference to FIGS.

FIG. 29 shows an example in which the robot has two movable legs, that is, a robot having two left and right feet 22L and 22R. Each foot 22L, 22R is provided with movable foot pieces 102A to 102D at four corners, respectively.
The equivalent ground area 700 is defined by envelopes 110L and 110R connecting the outer edges of the ground lines of the movable foot pieces 102A to 102D.
L, 700R are defined. In this case, a region surrounded by an envelope 702 connecting the entire outer edges of both the left and right equivalent ground regions 700L and 700R corresponds to the comprehensive ground region 704. And in this case, each movable foot piece 102A-10
The 2D only needs to be provided so as to be movable only in the direction in which the comprehensive ground area 704 is enlarged / reduced. That is, the equivalent ground regions 700L, 70R of the left and right foot 22L, 22R.
The OR does not need to be scaled up or down in the direction toward the space 706 between them (dashed arrow 708).
Therefore, from the viewpoint alone, the left and right foot 22
Movable foot piece 102 at the inner corner in the direction in which L and 22R are arranged
B and 102C need not be provided, but each foot 22
Considering the stability of each of the L and 22R, as shown by an arrow 710 in FIG.
It is desirable that 2B and 102C be configured to move in the front-back direction of the robot traveling direction. In this case, the movable foot pieces 102A and 102D at the outer corners may be moved in the radial direction as shown by an arrow 712 in FIG. 30, or may be moved in the front-back direction of the traveling direction of the robot. You may comprise.

FIG. 31 shows a case in which four movable legs are provided and four feet 22LF, 22RF, 22LR, 22RR are provided, and each movable foot piece 102A is formed in the same manner as in FIG. An example in which a moving direction of to 102D is determined is shown.

[0057]

According to the first aspect of the present invention, there is provided a foot structure of a legged walking robot having a plurality of movable legs, and providing a foot at the tip of each movable leg to enable free walking. At least one movable body capable of moving in a direction of enlarging / reducing an area (equivalent ground area) surrounded by an envelope connecting an outer edge of an effective ground plane with respect to a walking surface, for each of the foot bodies connected to the movable legs. Since the foot main body is provided with an operation mechanism for attaching the foot piece and moving the movable foot piece in the above-described direction, the walking state of the robot, for example, ascending and descending stairs, or obstacles on the walking surface The size of the equivalent contact area can be changed to maximize the stability of walking according to the presence of the object, the inclination of the walking surface, walking conditions such as walking speed, and even environmental factors such as earthquakes and strong winds. walking It can dramatically increase the stability of even walking under various circumstances, such as difficult.

According to the second aspect of the present invention, there is provided a contact detecting means for detecting whether or not the foot is in contact with the walking surface, and the operating mechanism is operated when the foot is not in contact with the walking surface. Since the operation mechanism is operated, it is possible to effectively prevent a remarkable load from being applied to the operation mechanism or a failure of the operation mechanism due to a reaction force from the walking surface when the foot lands.

According to the third aspect of the present invention, the operating mechanism is operated in a direction to reduce the area when the walking speed exceeds a predetermined value, according to the information of the control means for controlling the walking of the robot. Thus, when walking at high speed, the moment around the support leg of the free leg can be reduced, and the occurrence of a situation in which the robot falls down due to the effect of the moment can be effectively prevented.

According to the invention of claim 4, according to the information of the control means for controlling the walking of the robot, the operating mechanism is operated in a direction to reduce the area when walking up the stairs. Therefore, even when climbing a staircase where a stair-like protrusion is present at the upper end of the step portion of the staircase, it is possible to reduce the risk that the foot will interfere with the protrusion and fall down, especially As in the invention according to claim 5, when the user walks up the stairs, the operation mechanism operates to reduce the distance from the vertical projection position of the ankle joint of the leg on the foot to the front end of the effective ground plane in the traveling direction of the robot. By doing so, it is possible to reliably prevent the toe portion of the foot from interfering with the protrusion.

According to the invention of claim 6, according to the information of the control means for controlling the walking of the robot, the operating mechanism is operated in a direction to enlarge the area when walking down the stairs. Therefore, it is possible to increase the stability of the robot at the time of descending the stairs and reduce the possibility that the robot falls down. Particularly, when walking down the stairs as in the invention of claim 7, If the operating mechanism is operated to extend the distance from the vertical projection position of the ankle joint of the leg in the foot to the front end of the effective ground contact surface in the traveling direction of the robot, it is possible to reliably prevent falling when the stairs descend. Can be.

According to the invention of claim 8, according to the information of the control means for controlling the walking of the robot, the operating mechanism is operated in a direction to reduce the area when straddling the obstacle on the walking surface. Therefore, it is possible to prevent a situation in which the foot of the free leg interferes with the obstacle and causes the robot to fall when straddling the obstacle.

According to the ninth aspect of the present invention, according to the information of the control means for controlling the robot's walking, the operating mechanism is operated in a direction to enlarge the area when walking on a slope. Therefore, the stability of the robot when walking on a slope can be increased, and the robot can be prevented from falling.

According to the tenth aspect of the present invention, the earthquake detecting means is provided inside or outside the robot,
Since the operation mechanism is configured to operate in a direction to expand the area when an earthquake is detected, it is possible to increase the stability of walking of the robot and prevent the robot from falling when an earthquake occurs.

According to the eleventh aspect of the present invention, a transmission mechanism is interposed between the actuator of the operating mechanism and the movable foot piece, and this transmission mechanism is applied to the ground when the foot is grounded. Since the reaction force is not directly transmitted to the actuator, it is possible to effectively prevent the actuator of the operating mechanism from being broken by the reaction force.

According to the twelfth aspect of the present invention, when all the movable legs are in a stationary state and the respective feet are aligned in the front, rear, left, and right directions of the robot, the entire equivalent ground area of each foot is set. Since the movable foot piece is provided so as to expand and reduce the equivalent grounding area of each foot only in the direction of expanding and reducing the area surrounded by the envelope (the comprehensive grounding area), The enlargement / reduction of the equivalent ground area can be made to more effectively act on improving the stability of the robot.

According to the thirteenth aspect, the movable foot piece is provided so as to be linearly slidable in a plane parallel to the effective grounding surface. The stability of the walking of the robot can be increased by enlarging and reducing the equivalent grounding area by sliding in a horizontal direction, and in this case, the area of the equivalent grounding area can be changed in an analog manner. The equivalent ground area can be set to an optimum size according to the above.

According to the fourteenth aspect of the present invention, the movable foot piece is attached to the foot body so as to be rotatable about an axis in a direction parallel to the effective ground plane in a plane parallel to the effective ground plane. Since it is attached, the stability of the robot can be increased by rotating the movable foot piece according to the situation to enlarge / reduce the equivalent grounding area. As in the case, the equivalent ground area can be set to an optimal size according to the situation.

According to the fifteenth aspect of the present invention, the movable foot piece is rotatable about an axis parallel to the effective ground contact surface so that the movable foot piece can be raised and lowered with respect to the extension surface of the effective ground contact surface of the foot body. Since it is attached, by raising and lowering the movable foot piece according to the situation, reducing-expanding the equivalent grounding area,
The walking stability of the robot can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram generally showing an example of a control device for a legged walking robot according to the present invention.

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

FIG. 3 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.

FIG. 4 is a vertical sectional front view taken along the line IV-IV of the foot structure shown in FIG. 3;

FIG. 5 is a plan view showing an example of an operation state of the foot structure shown in FIG. 3;

FIG. 6 is a plan view showing another example of the operation state of the foot structure shown in FIG. 3;

FIG. 7 is a plan view showing still another example of the operation state of the foot structure shown in FIG. 3;

FIG. 8 is a flowchart showing an example of a control flow for operation of the foot structure of the present invention.

FIG. 9 is a schematic diagram showing a situation in which a two-legged robot to which the foot structure of the present invention is applied climbs stairs.

FIG. 10 is a schematic illustration showing a situation in which a two-legged robot to which the foot structure of the present invention is applied descends the stairs.

FIG. 11 is a schematic illustration showing a walking state of a two-legged robot to which the foot structure of the present invention is applied when an obstacle exists on a walking surface.

12 is a plan view showing an embodiment in which the operation mechanism of the foot structure shown in FIG. 3 is changed.

FIG. 13 is a plan view showing another embodiment of the foot structure shown in FIG. 3 in which an operation mechanism is changed.

FIG. 14 is a plan view showing still another embodiment of the foot structure shown in FIG. 3 in which an operation mechanism is changed.

FIG. 15 is a plan view showing another embodiment of the foot structure shown in FIG. 3 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;

18 is a longitudinal sectional view taken along line XVIII-XVIII in FIG.

19 is a longitudinal 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 longitudinal 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 partially cutaway bottom view showing another example in which the movable foot piece is moved linearly in a horizontal plane similarly to FIG.

FIG. 22 is a partially cutaway bottom view showing still another example in which the movable foot piece is moved linearly in a horizontal plane as in FIG.

FIG. 23 is a partially cutaway bottom view showing another example in which the movable foot piece is moved linearly in a horizontal plane as in FIG.

FIG. 24 is a plan view showing an example in which a movable foot piece is linearly moved in the front-rear direction in the traveling direction of the robot as the foot structure of one embodiment of the present invention.

FIG. 25 is a front view of the foot structure of FIG. 24;

26 is a longitudinal sectional view taken along line XXVI-XXVI in FIG. 24.

FIG. 27 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. 28 is a longitudinal sectional view taken along line XXVIII-XXVIII in FIG. 27.

FIG. 29 is a schematic plan view for explaining an example of a moving direction of a movable foot piece for each foot when the foot structure of the present invention is applied to a two-legged walking robot.

30 is a schematic plan view for explaining an example of a moving direction of a movable foot piece similarly to FIG. 29.

FIG. 31 is a schematic plan view for explaining an example of a moving direction of a movable foot piece for each foot when the foot structure of the present invention is applied to a four-legged walking robot.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Robot 2 Movable leg part 22,22L, 22R, 22LF, 22RF, 22L
R, 22RR Foot 26 Control unit 38 as control means 38 Ground sensor 72 Operating mechanism 74, 74A, 74B, 74E, 74F, 74G, 74
H, 74I Actuator 100 Foot body 102A, 102B, 102C, 102D, 102E,
102F, 102G, 102H Movable foot piece 109 Effective ground plane 110, 110R, 110L Envelope

──────────────────────────────────────────────────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 4-122586 (JP, A) JP Hei 3-184781 (JP, A) (58) Fields surveyed (Int. Cl. ⁷ , DB name) B25J 5/00

Claims (15)

(57) [Claims] 1. A foot structure of a legged walking robot having a plurality of movable legs and providing a foot at the tip of each movable leg so as to be free to walk, wherein a foot connected to each movable leg is provided. At least one movable foot piece that can move in a direction that enlarges / reduces the area surrounded by the envelope connecting the outer edge of the effective contact surface to the walking surface is attached to each of the flat body, and the movable foot piece is attached to A foot structure of a legged walking robot, wherein an operating mechanism for moving the foot in a direction is provided on the foot body. 2. The apparatus according to claim 1, further comprising a contact detecting means for detecting whether or not the foot is in contact with the walking surface, and operating the operating mechanism when the foot is not in contact with the walking surface. The foot structure of a legged walking robot according to item 1. 3. The method according to claim 1, wherein the operation mechanism is operated in a direction to reduce the area when the walking speed exceeds a predetermined value, according to information of the control means for controlling the walking of the robot. The foot structure of the legged walking robot described. 4. The leg-operated type according to claim 1, wherein the actuation mechanism is operated in a direction to reduce the area when walking up the stairs in accordance with information of the control means for controlling the walking of the robot. Foot structure of walking robot. 5. When the user walks up the stairs, the operating mechanism is operated to reduce a distance from a vertical projection position of an ankle joint of a leg on a foot to a front end of an effective ground contact surface in a traveling direction of the robot. The foot structure of the legged walking robot according to claim 4. 6. The system according to claim 1, wherein the operation mechanism operates in a direction to enlarge the area when walking down the stairs in accordance with information of the control means for controlling the walking of the robot.
The foot structure of a legged walking robot according to item 1. 7. When the user walks down stairs, the operating mechanism is operated so as to extend the distance from the vertical projection position of the ankle joint of the leg on the foot to the front end of the effective ground contact surface in the traveling direction of the robot. A foot structure for the legged walking robot according to claim 6. 8. The operation mechanism according to claim 1, wherein the operation mechanism is operated in a direction to reduce the area when straddling the obstacle on the walking surface in accordance with information of the control means for controlling the walking of the robot. Foot structure of a legged walking robot. 9. The legged walker according to claim 1, wherein the operation mechanism is operated in a direction in which the area is enlarged when walking on a slope, according to information of control means for controlling walking of the robot. Robot foot structure. 10. The apparatus according to claim 1, wherein earthquake detecting means is provided inside or outside the robot, and when the earthquake is detected, the operating mechanism is operated in a direction to enlarge the area. Foot structure of a legged walking robot. 11. A transmission mechanism is interposed between an actuator of the operating mechanism and the movable foot piece, and the transmission mechanism is configured to apply a force applied from the walking surface to the foot contact surface when the foot touches the ground. The foot structure of a legged walking robot according to claim 1, wherein the foot structure is configured not to directly transmit a force to the actuator. 12. A region surrounded by the entire envelope of the region of each foot when all the movable legs are in a standing upright state and each foot is aligned in the front, rear, left and right directions of the robot. The foot structure of a legged walking robot according to claim 1, wherein the movable foot piece is provided so as to expand and contract the area for each foot in the direction of expansion and contraction. 13. The foot of a legged walking robot according to claim 1, wherein the movable foot piece is linearly slidably mounted on the foot main body in a plane parallel to an effective ground plane. Construction. 14. The movable foot piece is attached to the foot body so as to be rotatable about an axis in a direction parallel to the effective ground plane in a plane parallel to the effective ground plane. 2. The foot structure of the legged walking robot according to 1. 15. The movable foot piece is mounted rotatably about an axis parallel to the effective ground plane so that the movable foot piece can be raised and lowered with respect to an extension plane of the effective ground plane of the foot body. 2. The foot structure of the legged walking robot according to 1.