JPH05318336A - Flat leg structure of leg type walking robot - Google Patents

Abstract

PURPOSE:To prevent effectively the production of difficulties in walking which are produced due to presence of obstacle in walking up and down stairs and flat surfaces, conditions on walking on slant surfaces and walking at high speed, and environmental factors such as earthquake, etc. CONSTITUTION:Movable flat leg pieces 102A to 102D movable in a direction that an area surrounded by an envelope 110 made by connecting the outer edges of an effective ground-contact surface is increased and decreased are provided on a flat leg main body 100. Then each movable flat leg piece is operated in that direction by an operation mechanism 72.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art Conventionally, various techniques have been proposed as to legged walking robots, and as a technique applicable to an autonomous bipedal walking type legged walking robot, Japanese Patent Laid-Open No. 62- 97005 and JP-A-62.
The technology disclosed in Japanese Patent Application Laid-Open No. 3-184781 has already been proposed by the applicant of the present invention as the foot structure of a bipedal walking robot. ..

[0003]

Among the legged walking robots, the bipedal walking type robot is inherently low in stability, and in addition to that, the situation of the walking surface such as the ground to be walked, the surrounding situation, and walking. It is often difficult to secure stability during walking depending on the speed and the like. That is, it is relatively easy to maintain stability when walking at low speed on a horizontal plane, but when climbing stairs, walking on a slope, or when there are obstacles on the walking surface, Furthermore, when the walking speed is high, walking with two legs tends to be unstable. In addition, it may be difficult to walk on two legs 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 walking robot, it is conceivable to design the foot so that the ground contact area with respect to the walking surface is large. However, simply increasing the foot size may adversely affect the stability depending on the walking situation. For example, if the walking surface is a staircase, there are often stair-shaped protrusions on the steps of each staircase. In such a case, if the foot is large, the staircase-like part will be formed when the stairs are raised. There is a strong risk that the toe side of the foot will interfere and fall. Further, in the case of straddling an obstacle such as a protrusion existing on the 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, interference easily occurs and a fall easily occurs. In addition to these, 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 a foot structure capable of always maintaining the stability of walking even when the condition of the walking surface, the walking speed, or the surrounding conditions change. The basic purpose is to provide.

[0006]

In order to solve the above-mentioned problems, according to the present invention, basically, the first aspect is
In the foot structure of a legged walking robot that includes a plurality of movable legs and has a foot at the tip of each movable leg, as shown in FIG. At least one movable foot piece, which is movable in a direction of enlarging or reducing the area surrounded by the envelope connecting the outer edge of the effective ground surface with respect to the walking surface, is attached to each of the foot bodies, and the movable foot piece is attached. An operating mechanism for moving in the direction is provided in the foot body.

[0007]

In the foot structure of the present invention, the area surrounded by the envelope connecting the outer edges of the effective ground contact surface with respect to the walking surface can be expanded / contracted by operating the movable foot piece by the operation mechanism. .. Here, the fulcrum that functions as a fulcrum with respect to the walking surface so that the robot does not fall when walking is that the outermost edge of the ground contact surface of each foot, especially the position of the axis of attachment of the movable leg (vertical ankle joint). Since it is the outer edge portion farthest from the projection position), the size (area) of the area surrounded by the envelope connecting the outer edges of the effective ground plane as described above is for supporting the movable leg with respect to the walking surface. This is equivalent to the size of the equivalent grounding area of the entire effective foot, and hence this area is hereinafter referred to as the equivalent grounding area in this specification.

As described above, in the structure of the present invention, the size of the equivalent ground area can be enlarged or reduced, so that, for example, ascending or descending stairs, presence of obstacles on the walking surface, inclination of the walking surface, The size of the equivalent grounding area can be selected so as to maximize the stability of walking depending on the walking condition such as walking speed and environmental factors such as earthquake.

[0009]

Embodiments of the present invention will be described below by taking a bipedal robot as an example of a legged mobile robot. FIG. 1 is an explanatory skeleton diagram schematically showing the entire robot 1, in which the left and right link-shaped movable legs 2 are 6
It is equipped with individual joints (each joint is
Shown by the electric motor that drives it). These six joints are, in order from the top, joints 10R and 10L for rotating the legs of the waist (around the z axis) (R on the right side, L on the left side; the same applies below), 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 knees, joints 18R and 18L in the pitch direction of the ankles, and joints 20R and 20L in the same roll direction, and below the movable foot pieces and The feet 22R and 22L having an actuating mechanism for actuating the movable foot piece are attached, and a housing (upper body) 24 is provided at the uppermost part, and inside the robot, an operation such as walking of the entire robot is performed. A control unit 26 is stored as control means for controlling the.

In the above, the hip joint is joint 10
R (L), 12R (L), 14R (L), and ankle joints are joints 18R (L), 20R (L)
It is composed of Further, 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 lower leg links 34R and 34L, respectively. Here, the movable leg 2 is provided with six degrees of freedom for each of the left and right feet, and by driving these 6 × 2 = 12 joints (axes) by appropriate angles during walking, It is configured so that it can walk in a three-dimensional space arbitrarily by giving a desired movement to the entire foot. As described above, each of the above-mentioned joints is composed of an electric motor and is further provided with a speed reducer that boosts the output of the electric motor. For details, refer to the application previously proposed by the applicant (Japanese Patent Application No. -324218, JP-A-3-1847
No. 82) and the like, which are not the gist of the present invention per se, and therefore, further description will be omitted.

In the robot 1 shown in FIG. 1, a well-known 6-axis force sensor 36 is provided at the ankle portion, and the 6-axis force sensor 36 is transmitted to the robot via the foot x, y ,. The force components Fx, Fy, Fz in the z direction and the moment components Mx, My, Mz around the directions are measured to detect the presence or absence of landing of the foot and the magnitude and direction of the force applied to the supporting leg. Further, at the four corners of the foot 22R (L), for example, a capacitance-type ground sensor 38 (not shown in FIG. 1) is used as ground detection means for detecting the presence or absence of ground contact with the walking surface of the foot.
Is provided. When the 6-axis force sensor 36 is used as the ground contact detecting means, the ground contact sensor 38 can be omitted. Further, the housing 24 has an inclination sensor 40.
The tilt sensor 40 detects the tilt angle with respect to the z axis in the xz plane and the yz plane, that is, the tilt angular velocity with respect to the gravity direction. Further, the electric motor of each joint is provided with a rotary encoder 46 (not shown in FIG. 1) that detects the amount of rotation thereof. Further, although omitted 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 fail protection. These outputs are sent to the control unit 26 in the housing 24 described above.

FIG. 2 is a block diagram showing the details of the control unit 26, which is composed of a microcomputer. Here, the output of the tilt sensor 40 or 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 arranged adjacent to the electric motor of each joint is sent to the RAM 5 via the counter 56.
4 and the outputs of the ground sensor 38 and the like are input to the RAM 54 via the waveform shaping circuit 58.
The control unit is provided with first, second and third arithmetic units 60, 62 and 63 each composed of a CPU.
The arithmetic unit 60 reads out a preset walking pattern such as a gravity trajectory stored in the ROM 64 to calculate a target joint angle, sends the calculated target joint angle to the RAM 54, and walks on the basis of the read walking pattern. To the third arithmetic unit 63. Further, the second arithmetic unit 62 reads out the target joint angle and the detected measured value from the RAM 54, calculates the control value necessary for driving each joint, and controls the D / A converter 66 and the servo amplifier 48. It outputs to the electric motor which drives each joint via. Further, the third arithmetic unit 63 reads out a signal indicating the presence or absence of grounding from the RAM 54, and actually detects the information on the walking condition given from the first arithmetic unit 60 and other actual walking conditions as necessary. Based on information from a device (not shown), such as an image sensor for detecting an obstacle or stairs, and an earthquake detector (not shown) provided inside or outside the robot. The control value necessary for the operation of the movable foot piece is calculated in accordance with the above situation, and the actuator 74 of the operation 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 specifically described 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 each of the following drawings, the foot is symmetrical unless otherwise specified, and therefore the reference symbols L and R are omitted and simply referred to as the foot 22. In FIGS. 3 and 4, the foot 22 includes a flat 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 in a plan view, and has a mounting center position of the movable leg portion 2 (more accurately,
The length from the vertical projection position of the ankle joint) O to the front end in the robot traveling direction (hence the length from the ankle to the toe) is
To be longer than the length from the attachment center position O to the rear end in the traveling direction (hence the length from the heel to the heel),
A mounting position for the movable leg 2 is defined. Then, on the lower surface side of the four corners of the foot main body 100, flat plate-like movable foot pieces 102A, 102B, 10 which are oval in plan view are formed.
2C and 102D are arranged, and these movable foot pieces 102A to 102D are rotatably supported by a vertical support shaft 104 in a horizontal plane (in a plane parallel to the ground plane). Each support shaft 104 is a foot main body 100.
It is configured so that it can be rotated about the axis by the operating mechanisms 72 arranged at the four corners on the upper surface side. As the actuating mechanism 72, in the illustrated example, a geared motor using an electric motor as an actuator (reference numeral 74 in FIG. 2), or an actuator 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 that each movable foot piece 10
It is determined that each support shaft 104 is eccentric with respect to the center position of 2A to 102D. Therefore, as will be described later, the movable foot pieces 102A to 102D change in the amount of protrusion to the outside from the foot main body 100 when viewed in plan when rotating.

Notched step portions 106 for accommodating the movable foot pieces 102A to 102D are formed at the four corners of the lower surface of the foot body 100, and the movable foot pieces 102A to 102D are formed. On the lower surface of the
8 is attached. In addition, in the actual foot, the lower edge portion 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 shown here for simplification of the drawing. Further, as shown in FIG. 2, 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 102A to 102D. The ground sensor is not shown in FIGS. 3 and 4 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 102
Only the lower surface of D, specifically, the lower surface of each elastic member 108 is an effective ground contact surface 109 for a walking surface such as a road surface during walking. An envelope connecting the outer edges of these effective ground planes 109 is shown by a chain double-dashed line 110 in FIGS. 3 and 5 to 7. The area surrounded by the envelope 110 is the above-mentioned equivalent ground area. The state shown in FIGS. 3 and 4 is a state in which the area of the equivalent ground area is the smallest, and if any of the actuation mechanisms 72 is actuated from this state, the movable foot piece corresponding thereto, for example, 102A, becomes a horizontal plane. The inside of the foot (therefore, the plane parallel to the effective ground plane) is rotated to rotate the foot main body 100.
The movable foot piece 102A is swung out from the notch step portion 106, and the amount of protrusion of the movable foot piece 102A with respect to the foot body 100 is increased, so that the equivalent ground area is expanded. FIG. 5 shows movable foot pieces 102A, 102 at two corners on the front end side in the traveling direction of the robot.
FIG. 6 shows a state in which B is swung diagonally forward at the same time, and FIG. 6 shows a state in which movable foot pieces 102C and 102D at two corners on the rear end side with respect to the traveling direction of the robot are swung diagonally backward at the same time. FIG. 7 shows all movable foot pieces 102A.
10 shows a state in which 102D is shaken out at the same time.

In this way, the movable foot pieces 102A-1
The equivalent ground area can be expanded / contracted by appropriately rotating 02D. Moreover, in this embodiment, since the operating mechanism 72 is provided in each of the movable foot pieces 102A to 102D, each movable foot piece 102A.
The 102D can be individually rotated. Therefore, for example, as shown in FIG. 5, a state in which only the movable foot pieces 102A and 102B on the front end side in the traveling direction of the robot are slanted forward to expand the equivalent grounding area only to the front side in the traveling direction, On the contrary, as shown in FIG. 6, only the movable foot pieces 102C and 102D on the rear side in the traveling direction can be swung out obliquely rearward to create a state in which the equivalent grounding area is expanded only on the rear side in the traveling direction. ..

FIG. 8 shows a flowchart for controlling the operation of the above-mentioned foot structure according to the walking condition. In FIG. 8, in the first step 200 after starting the control, whether or not it is predicted that a situation in which the equivalent ground contact area of the foot walks in the initial state and the walking becomes difficult will occur. Determine whether. Such a situation where walking becomes difficult means, for example, stairs rising, stairs descending, the presence of obstacles on the walking surface, slopes, other environmental factors such as the occurrence of earthquakes and strong winds, and an increase in walking speed. To do. This determination may be made in the third arithmetic unit 63 shown in FIG. 2 based on the information of the walking pattern to be walked, or the presence of stairs or the location of obstacles may be detected by an image sensor (not shown). The determination may be made based on the information obtained by actually detecting or by detecting the occurrence of an earthquake by the earthquake detecting means, or by using both in combination. In this step 200, if the occurrence of a situation where walking becomes difficult is predicted (YES), the process proceeds to the next step 202.
On the other hand, if not predicted (NO), as shown in step 214, the area of the equivalent ground region is not changed and the initial state is maintained, and the control loop ends. 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 ground contact surface of the foot is separated from the walking surface. This causes the actuator 74 of the foot actuating mechanism 72 to be driven (thus, the operation of the movable foot pieces 102A to 102D) only when the foot is away from the walking surface (not in contact with the ground). This is because. That is, when the movable foot pieces 102A to 102D are operated with the foot grounded, a remarkably large load is applied to the actuator 74 of the operation 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 by the ground detection signal from the ground sensor 38 provided in advance on the foot or the signal from the 6-axis force sensor 36. If it is determined in step 202 that the foot is not separated from the walking surface (NO), step 20
The process shifts to step 4 and waits until the foot separates from the walking surface, and after a predetermined time has elapsed, the process returns to step 202 again. On the other hand, when it is determined in step 202 that the foot is away from the walking surface (YES), the process proceeds to next step 206.

In step 206, each movable foot piece 10 is expanded or contracted in order to expand or contract the equivalent ground area.
The actuator 74 of the operating mechanism 72 corresponding to any one or two or more of 2A to 102D is driven. In this step 206, depending on the kind of situation predicted in step 200, there is a case where the operation is performed in the direction of expanding the equivalent ground area and a case where the operation is performed in the opposite direction of reducing the equivalent ground area. ..
In addition, a direction in which the equivalent ground area is expanded or contracted can be selected (for example, forward or backward of the traveling direction) according to the predicted type of situation. Moreover,
It is also possible to adjust the amount of change (enlargement amount or reduction amount) of the equivalent ground area according to the degree of difficulty of the predicted situation. It should be noted that settings such as expansion or contraction of the equivalent ground area, selection of expansion-reduction directionality, adjustment of expansion-reduction amount, etc. are normally made in step 200 described above.

Here, since an actual two-legged walking type robot has two movable leg portions 2, step 2
02,204,206 are left and right foot (22L, 22
R) will be executed individually or sequentially. After the equivalent ground area of the foot is enlarged or reduced in step 206 in this manner, the walking motion proceeds while maintaining that state, and during that time, the process proceeds to the next step 208. In step 208, it is determined whether the difficult walking condition has been resolved and the initial condition has been restored. That is, it is determined whether or not the difficult walking condition is resolved during the walking after the end of step 206. When it is determined in step 208 that the walking has not recovered from the difficult situation (NO), the process proceeds to step 210, the state is maintained as it is, and the process returns to step 208 again after a predetermined time elapses. On the other hand, if it is determined in step 208 that the walking is difficult, the process proceeds to step 212.

In step 212, the equivalent ground area is reduced or expanded so that the area of the equivalent ground area of the foot is returned to the initial area. That is, the operating mechanism 72
Of the movable foot piece 102 by operating the actuator 74 of
Return A to 102D to the initial position. Although not shown in FIG. 8 when executing step 212, the actuator 74 of the actuating 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 grounded on the walking surface, the actuator 74 is operated after waiting for the foot to separate from the walking surface. Note that this step 212 is also actually performed for each of the left and right feet (22R, 22L).
It will be executed individually or sequentially.

As described above, when there is a situation in which walking is predicted to be difficult, the equivalent ground contact area of the foot is expanded or reduced according to the situation and walking is performed. It is possible to ensure the stability of walking even under various conditions.

Next, an example of the kind of situation in which walking is difficult and the corresponding expansion or contraction of the equivalent ground area will be described with reference to FIGS. 9 to 11.

FIG. 9 shows a situation in which the robot 1 moves up the stairs 300. In many cases, the stairs 300 has a protrusion 302 projecting in the shape of a streak at the upper edge of the stepped portion. In this case, if the foot 22 is wide as shown by the phantom line in the figure, the tip of the foot 22 projects There is a risk of interfering with the portion 302 and falling. Therefore, when such a situation is predicted, the equivalent ground area of the foot 22 is reduced. In this case, the foot 2 may interfere with the protrusion 302.
Since it is the tip end portion of No. 2, the equivalent ground 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 shorten 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 the situation when the robot 1 descends the stairs 300. When descending the stairs 300, a moment to fall toward the forward direction of the robot 1 (downward direction of the stairs) is applied to the robot 1, so that if the area of the equivalent ground area of the foot 22 is small, the robot 1 will easily fall. Become. Therefore, when such a situation is predicted, the equivalent ground 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 ankle to the toe) is, the more it is possible to prevent the foot 22 from falling forward. The equivalent ground area may be expanded on the front end side. In other words, the actuator 74 of the operating mechanism 72 is designed to extend 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 front end (toe) of the equivalent ground area. Should be operated.

FIG. 11 shows a situation in which a walking surface 306 has an obstacle, for example, a protrusion 304. In this case, if the equivalent ground area of the foot 22 is wide, the movable leg 2 on the free leg side
The tip of the foot 22 interferes with the obstacle 304 at the time of swinging up, and the foot 2 is also moved at the time of swinging down the movable leg 2 on the free leg side.
There is a risk that the rear end of the robot 2 may interfere with the obstacle 304 and the robot 1 may fall. Therefore, in this case, the foot 22
If the equivalent grounding area is reduced, the risk of tipping as described above can be avoided.

Further, although not shown in particular, when the walking surface is a slope, the robot 1 falls down on the slope in any case of 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 expanded.

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 easily interferes during walking, and the robot easily falls. Therefore, when walking at a high speed, it is possible to reduce the equivalent grounding area of the foot 22 and thereby reduce the risk of falling. In this case, if the walking speed is expected to exceed a predetermined speed, the equivalent ground contact area of the foot 22 may be controlled to be reduced. Of course, the equivalent ground area may be changed stepwise according to the walking speed.

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

Next, several other embodiments of the foot structure according to the present invention, particularly an embodiment in which the mechanical portion is modified, are shown in FIG.
~ It demonstrates with reference to FIG.

FIG. 12 shows the operating foot pieces 102A to 102D.
An example in which the actuating mechanism 72 for actuating the is different from the embodiment of FIGS. 3 and 4 is shown. In this case, the support shaft 104 of each movable foot piece 102A to 102D and each movable foot piece 10
An actuator 74 such as an electric motor or a fluid pressure rotary actuator provided corresponding to 2A to 102D
The worm gear 402 is interposed as a transmission mechanism between the rotary shaft 404 and the rotary shaft 404.

In the example of FIG. 12, as in the examples of FIGS. 3 and 4, when the actuator 74 is driven, the movable foot pieces 102A to 102 are moved through the worm gear 402.
D is individually rotated in a plane parallel to the ground plane, so that the equivalent ground region can be expanded / contracted in any direction. Further, in this example, the worm gear 402 is interposed as a transmission mechanism between the actuator 74 and each of the movable foot pieces 102A to 102D, and the reaction force from the walking surface applied to the ground surface when the foot touches the rotary shaft 404.
It is possible to prevent the reaction force from being directly applied to the actuator 74 and causing a significant increase in load or failure of the actuator 74, since the reaction force is absorbed by the bending.

In FIG. 13, the embodiment shown in FIG. 12 is further modified so that 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 is moved. Two movable foot pieces 102C on the side,
An example in which the actuating mechanism 72 is configured to actuate 102D simultaneously is shown. In FIG. 13, a rotary drive type actuator 74A common to the two movable foot pieces 102A and 102B on the front side in the moving direction of the robot, and two movable foot pieces 102 on the rear side in the moving direction of the robot are shown.
A rotary drive type actuator 74B common to C and 102D is provided. Actuator 7
The rotational driving force of 4A is transmitted via the bevel gear mechanism 406A to the two worm gears 402A having a common shaft on the drive side.
402B, these worm gears 402A,
By 402B, the rotating foot pieces 102A and 102B are simultaneously rotated in opposite directions.
Similarly, the rotational driving force of the actuator 74B also has a common shaft on the driving side via the bevel gear mechanism 406B.
The worm gears 402C and 402D are provided so that the worm gears 402C and 402D can simultaneously rotate the movable foot pieces 102C and 102D in opposite directions.

In such an example of FIG. 13, the equivalent grounding area in front of the foot 22 in the advancing direction can be simultaneously enlarged / reduced, and on the both sides in the advancing direction of the foot 22 on the both sides. At the same time, the equivalent ground area can be expanded / contracted rearward in the traveling direction.

FIG. 14 shows all movable foot pieces 102A.
An example in which the actuation mechanism 72 is configured to actuate 102D simultaneously is shown. In this case, all movable foot pieces 102A-
One rotation drive type actuator 7 for 102D
4E is provided, and the rotational driving force of the actuator 74E is two bevel gear mechanisms 406A and 406B and four worm gears 402A to 402A-4 similar to the example shown in FIG.
The movable foot pieces 102A to 102D are simultaneously given via 02D, and the movable foot pieces 102A to 102D are simultaneously turned. Therefore, in this example, the equivalent ground area expands / contracts simultaneously in all directions.

In the examples shown in FIGS. 13 and 14, too,
Bevel gear mechanisms 406A, 4 are provided between the actuators 74A to 74D; 74E and the movable foot pieces 102A to 102D.
06B and worm gears 402A to 402D are interposed as a transmission mechanism, and in this case also, the reaction force received from the walking surface to the ground contact surface can be absorbed by the bending of each intermediate shaft.

FIG. 15 shows each movable foot piece 102A-10.
Another example for simultaneously activating 2D is shown. Figure 1
5, the support shaft 1 of each movable foot piece 102A to 102D
Each of the actuators 04 is provided with a pulley 410, and as the actuator 74 of the actuating mechanism 72, a rotary drive type actuator is provided as described above. A pulley 412 is also provided on the rotary shaft of the actuator 74,
Four pulleys 41 on the movable foot pieces 102A to 102D side
A common endless annular belt 414 is wound around the 0 and the pulley 412 on the actuator 74 side. Therefore, by driving the actuator 74, the belt 41
4 cycles, which results in each pulley 410, 412
Can be rotated to simultaneously rotate the movable foot pieces 102A to 102D simultaneously. That is, the equivalent ground area can be enlarged / reduced in all directions at once. In this case, sprockets 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 is used.
The movable foot pieces 102A to 102D are configured so that the equivalent ground area is expanded / reduced by rotating 102D within a horizontal plane (a plane parallel to the effective ground surface).
Of course, the moving direction of 02D is not limited to this. 16 to 26, movable foot pieces 102A to 102 are shown.
An example is shown in which the equivalent ground area is enlarged / reduced by linearly moving D in a plane parallel to the effective ground plane.

First, in the embodiment shown in FIGS. 16 to 18, the movable foot pieces 102A to 102D, which are rectangular in plan view, are formed on the lower surfaces of the four sides of the foot main body 100, for example.
Are arranged. These movable foot pieces 102A-10
An elastic material 108 is attached to each of the lower surfaces of the 2D, and the lower surface of the elastic material 108 serves as an effective grounding surface 109. The tips of the advancing / retreating shafts 500A to 500D are fixed to the movable foot pieces 102A to 102D, respectively. The advancing / retreating of these advancing / retreating shafts 500A to 500D causes the movable foot pieces 102A to 102D to move in the radial direction of the foot body 100. To expand / reduce the above-mentioned equivalent ground area. As the actuator 74 of the operating mechanism 72 for advancing / retreating each of the advancing / retreating 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 movable foot piece 102A-10.
A rotary drive type actuator such as an electric motor is used as the actuator 74 of the actuating 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 screw mechanism 504 and transmitted. An example of the structure configured to do so will be described for the portion of the movable foot piece 102A corresponding to FIG. In FIG. 19, a female screw portion 508 formed on the advancing / retreating shaft 500A is screwed onto a screw shaft 506 rotated by a rotary drive type actuator 74. Therefore, the forward / backward movement of the shaft
A moves back and forth, and along with this, the movable foot piece 102A also moves back and forth. Although not shown in FIG. 19, the operating mechanisms for the other movable foot pieces 102B to 102D have the same configuration.

FIG. 20 shows each movable foot piece 102A-10.
A rotary drive type actuator such as an electric motor is used as the actuator 74 of the actuating mechanism 72 for linearly moving the 2D forward and backward, and the rotary drive force of the actuator 74 is used as the rack-pinion mechanism 5 as in the example of FIG.
An example of a configuration in which 10 is converted to a linear driving force and transmitted will be shown for the movable foot piece 102A corresponding to FIG. In FIG. 20, a pinion 512 rotated by a rotary drive type actuator 74.
Further, the rack 514 integrated with the advancing / retreating drive shaft 500A is meshed, and therefore the advancing / retreating shaft 500A advances / retreats by the rotational driving of the actuator 74, and the movable foot piece 102A also advances / retreats with this. The other movable foot pieces 102B to 102D are similarly configured.

FIG. 21 shows the movable foot piece 102 as described above.
In a foot structure of a type in which A to 102D are linearly moved to expand and contract the equivalent ground area, in particular, the movable foot pieces 102A to 102D are simultaneously moved using a common and single actuator 74. Here is an example. In this example, as the actuator 74, the driving side (fluid pressure applying side) of the four fluid pressure cylinders 516A to 516D is used.
The one that is integrated is used. Other configurations are similar to those of the example shown in FIGS. In this case, the fluid pressure is injected into the driving side of the actuator 74 or discharged from the driving side of the actuator 74.
00A-500D are moved back and forth all at once, and each movable foot piece 10
2A to 102D can be moved back and forth all at once, and the above-mentioned equivalent ground region can be expanded or reduced all at once.

FIG. 22 shows each movable foot piece 10 as described above.
Another example in which 2A to 102D are moved back and forth simultaneously in a straight line will be shown. In FIG. 22, the operating mechanism 72
As the actuator 74, a rotary drive type such as an electric motor (including a geared motor) is used, 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 attached to a portion near the outer circumference of the rotating body 522.
Advancing / retreating shafts 500A-500D of -102D are connected via links 522A-522D, respectively. Note that guides 524A to 524D for guiding the linear behavior in the axial direction are provided for the advancing / retreating shafts 500A to 500D. Even in such an embodiment, the rotation driving force of the rotation driving type actuator 74 is equal to the link 522A.
It is converted into a linear driving force by a link mechanism including .about.522D, and the movable foot pieces 102A-102D move forward and backward simultaneously through the forward / backward movement shafts 500A-500D.

In FIG. 23, movable foot pieces 102A to 102 are shown.
In a foot structure that moves D straight, especially 18
An example is shown in which a pair of movable foot pieces located on the symmetrical side in the 0 ° direction are simultaneously moved by using a rack-pinion mechanism. In FIG. 23, movable foot pieces 102A, 10
A rotary drive type actuator such as an electric motor is provided as a common actuator 74 for 2C, and a rotary drive shaft 524 of the actuator 74 is provided with a pinion 526. The pinion 526 has a movable foot piece. The rack 527A integrated with the advancing / retreating shaft 500A of the 102A, and the advancing / retreating shaft 50 of the movable foot piece 102C.
The rack 527C integrated with 0C meshes.
And advance / retreat shafts 500A, 500C, racks 527A, 5
For 27C, a guide 5 to guide the advance / retreat
28,530 are provided. The actuation mechanism for the remaining two movable foot pieces 102B and 102D has the same structure as above, but is omitted for convenience of the drawings. Such a figure 2
In the example of No. 3, by operating the rotary drive type actuator 74, the movable foot pieces 102A, 10A on the symmetrical side are moved.
2C can be moved back and forth at the same time, and the remaining movable foot pieces 102B and 102D can be moved back and forth at the same time by operating another rotation drive type actuator (not shown).

24 to 26, two movable foot pieces 102A and 102B on both sides in front of the robot in the advancing direction are linearly moved back and forth at the same time, and two movable foot pieces on both sides in the advancing direction of the robot are on both sides. An example is shown in which the pieces 102C and 102D are linearly moved back and forth simultaneously. 24 to 26
In the four side portions of the foot main body 100 having a rectangular shape in plan view, a movable foot piece 102 is provided on the lower surface side at a position corresponding to both left and right sides of one side on the front end side in the traveling direction of the robot.
A and 102B are arranged, while movable foot pieces 102C and 102D are arranged 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 as described above, and the lower surface serves as an effective grounding surface 109. A convex or concave guided portion 531 is formed on both upper sides of the movable foot pieces 102A and 102B. Correspondingly, the guided portion 531 can linearly slide on the foot main body 100. Portion 532 that engages with
Are formed. These guide portions 532 guide the movable foot pieces 102A and 102B in a direction parallel to the traveling direction of the robot (front-rear direction), and a reaction force from the walking surface applied to the movable foot pieces 102A and 102B at the time of contact with the ground. It is for receiving. On the other hand, the movable foot pieces 102C and 102D on the rear end side in the moving direction of the robot are also configured to be guided and supported by the foot main body 100 along the moving direction of the robot. Are omitted for convenience of the drawings.

Movable foot piece 1 on the front end side in the traveling direction of the robot
02A and 102B are a single and common rotary drive type actuator 74F, for example, an operating mechanism 7 including an electric motor.
The robot 2F is configured to be linearly moved forward and backward in the front-rear direction of the moving direction of the robot by the 2F. That is, the rotational driving force of the actuator 74F is the bevel gear mechanism 5
34 is transmitted to the intermediate common rotating shaft 536, and the rotating force of the intermediate rotating shaft 536 is transmitted to the bevel gear mechanism 538A,
The rotation of the screw shafts 540A, 540B transmitted to the screw shafts 540A, 540B via the 538B is converted into a linear motion by the female screw blocks 542A, 542B screwed to the screw shafts 540A, 540B, and these female screw screws are rotated. The movable foot pieces 102A and 102B fixed to the blocks 542A and 542B are linearly moved back and forth. On the other hand, the movable foot pieces 102C and 102D on the rear end side in the moving direction of the robot are also linear in the front-rear direction in the moving direction of the robot at the same time by the single and common rotary drive type actuator 74G, for example, the operating mechanism 72G equipped with an electric motor. It is configured to be moved back and forth. 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, 5C.
38D is transmitted to the screw shafts 540C and 540D, and the rotation of the screw shafts 540C and 540D is
The female foot blocks 542C and 542D screwed onto the screw shafts 540C and 540D are converted into linear motions, and the movable foot pieces 102C and 102D fixed to the female screw blocks 542C and 542D are moved rectilinearly.

In the embodiment shown in FIGS. 24 to 26, the movable foot pieces 102A, 102 on the front end side in the traveling direction of the robot are driven by driving the actuator 74F.
2B can be moved forward and backward at the same time in the moving direction of the robot, and the equivalent ground area can be enlarged / reduced only in the forward direction of the robot. Conversely, by driving the actuator 74G, the movable foot pieces 102C and 102D on the rear end side of the robot in the advancing direction are moved back and forth simultaneously in the advancing direction of the robot, and the equivalent ground area is expanded only in the rear of the advancing direction of the robot. It can be reduced.

27 and 28, the movable foot pieces 102E to 102H are rotated about an axis (horizontal axis parallel to the ground plane) which is horizontal with respect to the foot main body 100. 4 shows a foot structure according to an embodiment in which the movable foot pieces 102E to 102H are undulated with respect to the extension surface of the effective ground surface 109 of the foot main body 100, thereby expanding / reducing the equivalent ground area.

In FIGS. 27 and 28, the foot main body 100 is formed in a rectangular flat plate shape when seen in a plan view, and the bottom surface of the foot main body 100 has a front end side and a rear end side in the robot advancing direction. An elastic material 108 is attached to each, and the lower surface of the elastic material 108 serves as an effective ground surface 109. Foot body 10
A movable foot piece 102E is attached to the front end of the moving direction 0 of the robot so as to be rotatable about a horizontal support shaft 600 that is orthogonal to the moving direction of the robot. On the other hand, a movable foot piece 102F is attached to the rear end of the foot main body 100 in the advancing direction so as to be rotatable about a horizontal support shaft 602 which is orthogonal to the advancing direction of the robot.
Furthermore, on the left and right sides of the rear part of the foot body 100 in the traveling direction,
Spindles 604, 6 that are parallel and horizontal to the direction of movement of the robot
Movable foot piece 10 so as to be rotatable around 06
2G and 102H are attached. Elastic materials 108 are provided on the back surfaces of the movable foot pieces 102E to 102H, respectively.
Is attached.

A movable foot piece 10 at the front end of the robot in the traveling direction.
2E is configured to be rotated (i.e., undulated) 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 body 100.
H is fixed, and the screw shaft 608 having a vertical axis is rotated by its actuator 74H. And this screw shaft 60
A female screw block 610 is screwed into the shaft 8, and the female screw block 610 and the movable foot piece 102E are connected by a link piece 612. Here, if the actuator 74H is driven, the screw shaft 608
The female screw block 610 ascends and descends with the rotation, and the movable foot piece 102E is undulated by the link piece 612. On the other hand, the movable foot piece 102 at the rear end of the robot in the traveling direction
F and movable foot pieces 10 on both sides of the rear end of the robot in the traveling direction
2G and 102H are those movable foot pieces 102F to 10F.
Actuator 7 including a rotary drive type actuator 74I such as an electric motor (including a geared motor) common to 2H
2I is configured to rotate (that is, undulate) between an upright state and a horizontal state. Specifically, the rotary drive type actuator 74I is fixed to the foot body 100.
The screw shaft 614 having a vertical axis is rotated by I. A female screw block 616 is screwed onto the screw shaft 614, and the female screw block 616 and each movable foot piece 1 are further attached.
Link pieces 618 and 6 between 02F and 102H, respectively.
They are connected by 20,622. When the actuator 74I is driven, the female screw block 616 moves up and down as the screw shaft 614 rotates, and the movable foot piece 102F is moved by the link pieces 618, 620, 622.
˜102H is undulated at the same time.

In this embodiment, by driving the actuator 74H, the movable foot piece 102E at the front end in the robot advancing direction is undulated with respect to the extension surface of the effective installation surface of the foot main body 100, whereby the front side in the robot advancing direction. 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 advancing direction.
102G simultaneously undulates with respect to the extension surface of the effective installation surface of the foot main body 100, thereby digitally reducing-enlarging the equivalent grounding area toward the rear side and the rear end side with respect to the robot traveling direction. You can

As described above, in each of the embodiments shown in FIG. 3 to FIG. 7 and FIG. 12 to FIG. 28, regarding the legged walking robot having a plurality of movable leg portions, one leg of the movable leg portion is used. I took out Taira and explained it. Here, basically, the feet of all the movable legs need to have the same shape (the same structure) or the symmetrical shape (the symmetrical structure). However, regarding the feet of all the plurality of movable legs, In consideration at the same time, it is preferable that the direction in which the equivalent ground area of each foot is to be expanded / contracted (movable direction of each movable foot piece) is 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 of the robot, left and right, surrounded by the entire envelope of the equivalent ground area of each foot. The area covered by the foot (hereinafter referred to as the comprehensive grounding area) is expanded-The equivalent grounded area of each foot is expanded in the direction of reduction-
It is preferable to provide the movable foot piece so as to reduce the size. A specific example thereof will be described below with reference to FIGS. 29 to 31.

FIG. 29 shows an example of a robot having two movable legs, that is, a robot having two left and right feet 22L and 22R. Each foot 22L, 22R has movable foot pieces 102A-102D at its four corners,
The equivalent ground area 700 is defined by the envelopes 110L and 110R that connect the outer edges of the ground lines of the movable foot pieces 102A to 102D.
L, 700R is specified. In this case, the area surrounded by the envelope 702 that connects the outer edges of both the left and right equivalent ground areas 700L and 700R corresponds to the comprehensive ground area 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 of enlarging / reducing the comprehensive ground area 704. That is, the equivalent ground areas 700L and 70L of the left and right feet 22L and 22R, respectively.
The 0R does not need to be expanded / contracted in the direction toward the space portion 706 between them (broken line arrow 708).
Therefore, from that perspective alone, the left and right foot 22
Movable foot piece 102 at the inner corner in the direction in which L and 22R are lined up
B and 102C may not be provided, but each foot 22
Considering the stability of each of 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 indicated by the arrow 712 in FIG. 30, or may be moved in the front-back direction of the robot's traveling direction. It may be configured.

FIG. 31 shows a case where each movable foot piece 102A has four movable legs and four feet 22LF, 22RF, 22LR, 22RR, in the same way as in FIG. An example in which a moving direction of 102D is determined will be shown.

[0057]

According to the invention of claim 1, in a foot structure of a legged walking robot, which is provided with a plurality of movable legs, and a foot is provided at the tip of each movable leg to allow walking. At least one movable body that can move in a direction in which each of the foot main bodies coupled to each movable leg portion expands and contracts an area (equivalent ground area) surrounded by an envelope connecting the outer edge of the effective ground surface with respect to the walking surface. Since the foot body is provided with an operating mechanism for attaching the foot piece and moving the movable foot piece in the direction, the robot walks, for example, the stairs rise and fall, or the obstacle on the walking surface. It is possible to change the size of the equivalent grounding area in order to maximize the stability of walking, depending on the existence of the pedestrian, the inclination of the walking surface, walking conditions such as walking speed, and 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 ground contact detection means for detecting whether or not the foot is in contact with the walking surface, and the actuating mechanism is operated when the foot is not in contact with the ground. Since it is operated, it is possible to effectively prevent a remarkably large load from being applied to the operating mechanism or a failure of the operating mechanism due to the reaction force from the walking surface when the foot is landed.

According to the invention of claim 3, according to the information of the control means for controlling the walking of the robot, when the walking speed exceeds a predetermined value, the operating mechanism is operated in the direction of reducing the area. Therefore, it is possible to reduce the moment around the supporting leg of the free leg when walking at a high speed, and thus it is possible to effectively prevent a situation in which the robot falls due to the influence of the moment.

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 the direction of reducing the area when walking up the stairs. Therefore, even when climbing a staircase where there is a ridge-like protrusion on the upper end of the step of the stairs, it is possible to reduce the risk that the foot will interfere with the protrusion and fall. As in the invention of claim 5, when the user walks up the stairs, the actuating mechanism is operated to shorten 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 plane in the robot advancing direction. By doing so, it is possible to reliably prevent the toe side portion of the foot from interfering with the protrusion.

According to the sixth aspect of the present invention, the operating mechanism is operated in the direction of enlarging the area when walking down the stairs according to the information of the control means for controlling the walking of the robot. 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 may fall 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 plane in the robot moving direction, it is possible to reliably prevent the fall when the stairs descend. You can

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

According to a ninth aspect of the present invention, the operating mechanism is configured to operate in a direction of enlarging the region when walking on a slope according to the information of the control means for controlling the walking of the robot. Therefore, it is possible to increase the stability of the robot when walking on the slope and prevent it from falling.

According to the tenth aspect of the invention, means for detecting an earthquake is provided inside or outside the robot,
When the earthquake is detected, the operating mechanism is configured to operate in the direction of expanding the area, so that the stability of the walking of the robot can be increased and the fall of the robot can be prevented when the earthquake occurs.

According to the invention of claim 11, a transmission mechanism is interposed between the actuator of the actuating mechanism and the movable foot piece, and the transmission mechanism is applied to the grounding surface when the foot is grounded. Since the reaction force is configured not to be directly transmitted to the actuator, it is possible to effectively prevent the actuator of the operating mechanism from being damaged by the reaction force.

According to the twelfth aspect of the present invention, when all the movable legs are in a stationary state and each foot is aligned in the front, rear, left and right directions of the robot, the entire equivalent ground area of each foot is Since the movable foot pieces are provided so as to expand and contract the equivalent ground area for each foot only in the direction in which the area surrounded by the envelope (inclusive ground contact area) is expanded and contracted, The expansion / reduction of the equivalent ground area can be more effectively applied to the improvement of the stability of the robot.

According to the thirteenth aspect of the present invention, since the movable foot piece is linearly slidable in a plane parallel to the effective ground contact surface, the movable foot piece can be linearly slid according to the situation. Since the stability of the robot's walking can be increased by sliding the slider to expand and contract the equivalent ground area, and in this case, the area of the equivalent ground 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 invention, the movable foot piece is provided in the foot main body so that the movable foot piece can rotate about an axis in a direction orthogonal to the effective ground contact surface in a plane parallel to the effective ground contact surface. Since the robot is attached, the stability of the robot can be increased by rotating the movable foot piece according to the situation and enlarging / reducing the equivalent ground area. In this case also, the stability of the robot can be increased. As in the case, the equivalent ground area can be set to an optimum size according to the situation.

According to the fifteenth aspect of the invention, the movable foot piece is rotatable about an axis parallel to the effective ground surface so that the movable foot piece can rise and fall with respect to the extension surface of the effective ground surface of the foot body. Since it is attached, by raising and lowering the movable foot piece according to the situation to reduce and expand the equivalent ground area,
The walking stability of the robot can be improved.

[Brief description of 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 of a foot structure according to an embodiment of the present invention in which a movable foot piece is configured to rotate in a horizontal plane.

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

FIG. 5 is a plan view showing an example of an operating condition of the foot structure shown in FIG.

6 is a plan view showing another example of the operating condition of the foot structure shown in FIG. 3. FIG.

FIG. 7 is a plan view showing still another example of the operating condition of the foot structure shown in FIG.

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

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

FIG. 10 is a schematic diagram showing a situation of a two-legged robot to which the foot structure of the present invention is applied when descending stairs.

FIG. 11 is a schematic diagram showing a walking condition in the case where an obstacle is present on a walking surface of a two-legged robot to which the foot structure of the present invention is applied.

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

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

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

15 is a plan view showing another embodiment of the foot structure shown in FIG. 3 in which the operating mechanism is changed.

FIG. 16 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 a horizontal plane.

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

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

19 is a vertical cross-sectional view showing the foot structure shown in FIG. 16 in which the actuating mechanism is changed, at the same position as in FIG.

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

FIG. 21 is a partially cutaway bottom view showing another example in which the movable foot piece is linearly moved in the horizontal plane as in FIG. 16.

FIG. 22 is a partially cutaway bottom view showing still another example in which the movable foot piece is linearly moved in the horizontal plane as in FIG. 16.

FIG. 23 is a partially cutaway bottom view showing another example in which the movable foot piece is linearly moved in the horizontal plane as in FIG. 16.

FIG. 24 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 of the traveling direction of the robot.

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

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

FIG. 27 is a partially cutaway perspective view showing an example in which a movable foot piece is undulated as a foot structure according to an embodiment of the present invention.

28 is a vertical 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-leg type walking robot.

FIG. 30 is a schematic plan view for explaining an example of the moving direction of the 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]

1 Robot 2 Movable legs 22, 22L, 22R, 22LF, 22RF, 22L
R, 22RR Foot 26 Control unit 38 as control means 38 Grounding sensor 72 Actuating mechanism 74, 74A, 74B, 74E, 74F, 74G, 74
H, 74I actuator 100 foot main body 102A, 102B, 102C, 102D, 102E,
102F, 102G, 102H Movable foot piece 109 Effective ground plane 110, 110R, 110L Envelope

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor ▲ Takahashi Hideaki 1-4-1 Chuo, Wako-shi, Saitama, Honda R & D Co., Ltd. (72) Inventor Takashi Matsumoto 1--4, Chuo, Wako, Saitama No. 1 inside Honda R & D Co., Ltd. (72) Inventor Akira Takeno 1-4-1 Chuo, Wako, Saitama Inside Honda R & D Co., Ltd.

Claims (15)

[Claims] 1. A foot structure of a legged walking robot, comprising a plurality of movable legs, wherein a foot is provided at a tip of each movable leg so that the leg can walk freely. Each of the flat bodies is provided with at least one movable foot piece movable in a direction of enlarging and reducing an area surrounded by an envelope connecting the outer edge of the effective ground surface with respect to the walking surface, and the movable foot piece is described above. A foot structure of a legged walking robot, characterized in that an actuating mechanism for moving in a direction is provided on the foot body. 2. The grounding detection means for detecting whether or not the foot is in contact with the walking surface is provided, and the actuating mechanism is operated when the foot is not in contact with the ground. The foot structure of the legged walking robot described in. 3. The actuating mechanism is operated in a direction to reduce the area when the walking speed exceeds a predetermined value, according to information of a control means for controlling walking of the robot. Foot structure of the described legged walking robot. 4. The leg type according to claim 1, wherein the actuating mechanism is operated in a direction of reducing the area when walking up a stairway in accordance with information from a control unit that controls the walking of the robot. Foot structure of walking robot. 5. When moving up the stairs, the actuating mechanism is operated to shorten 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 plane in the robot advancing direction. The foot structure of the legged walking robot according to claim 4. 6. The operating mechanism is operated in a direction of enlarging the region when walking down stairs according to information from a control unit that controls the walking of the robot.
The foot structure of the legged walking robot described in. 7. When the robot walks down the stairs, the actuating mechanism is operated so as 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 plane in the robot advancing direction. The foot structure of the legged walking robot according to claim 6. 8. The operation mechanism according to claim 1, wherein the operating mechanism is operated in a direction of reducing the area when straddling an obstacle on a walking surface according to information of a control unit that controls walking of the robot. Foot structure of a legged walking robot. 9. The legged walking according to claim 1, wherein the operating mechanism is operated in a direction of enlarging the region when walking on a slope according to information of a control means for controlling walking of a robot. Robot foot structure. 10. The earthquake detecting means is provided inside or outside the robot, and when the earthquake is detected, the actuating mechanism is operated in a direction of expanding the area. Foot structure of a legged walking robot. 11. A transmission mechanism is interposed between the actuator of the actuation mechanism and the movable foot piece, and the transmission mechanism is applied from the walking surface to the grounding surface of the foot when the foot touches the ground. The foot structure of the legged walking robot according to claim 1, wherein the foot structure is configured not to directly transmit a force to the actuator. 12. An area surrounded by the entire envelope of the area of each foot in a state where all the movable legs are in a stationary upright state and each foot is aligned in the front-rear direction and the left-right direction of the robot. The foot structure of the 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 a direction of enlarging and contracting. 13. The foot of a legged walking robot according to claim 1, wherein the movable foot piece is linearly slidably attached to the foot body in a plane parallel to the 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 orthogonal to the effective ground plane in a plane parallel to the effective ground plane. The foot structure of the legged walking robot described in 1. 15. The movable foot piece is rotatably attached about an axis parallel to the effective ground surface so that the movable foot piece can rise and fall with respect to an extension surface of the effective ground surface of the foot body. The foot structure of the legged walking robot described in 1.