JP2002096281A - Bipedal walking robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple and inexpensive bipedal walking robot capable of performing the attitude balance in the lateral direction of the robot without using any motor having the axis of rotation in the longitudinal direction of the robot on ankles and the waist. SOLUTION: A center side flat surface 9 of the robot in contact with a floor surface when the robot is erected and a robot side flat surface 10 inclined diagonally upward when the robot is erected are provided on a right sole 8, and a center side flat surface 18 of the robot in contact with the floor surface when the robot is erected and a robot side flat surface 19 inclined diagonally upward when the robot is erected are provided on a left sole 17. In a walking mode, in order to keep the attitude balance in the lateral direction of the robot, the attitude of the robot is controlled so that an appropriate flat surface out of the two flat surfaces of the right sole 8 and the left sole 17 is brought into contact with the floor surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides an easily implemented means for causing a bipedal walking robot to walk without falling over.

[0002]

2. Description of the Related Art In order to realize walking of a robot having two legs, it is important to control the center of gravity so that the robot does not fall in the left and right directions with respect to the traveling direction of the robot.

Conventionally, as a technique for causing a bipedal walking robot to walk without falling in the left and right directions with respect to the traveling direction, an actuator such as a motor having a rotating shaft at the ankle or waist in the same direction as the traveling direction of the robot has been known. By controlling this actuator, the center of gravity of the robot is shifted to the supporting leg side when one leg is floating, and the robot is overturned by controlling the balance of the center of gravity of the robot in the left and right direction It was common to walk without walking.

[0004]

However, in this type of system, in order to balance the center of gravity of the robot in the left-right direction with respect to the traveling direction, a motor having an ankle or a waist with a rotation axis in the same direction as the traveling direction of the robot is used. It is essential to equip For this reason, there is a drawback that the mechanical system becomes complicated and expensive in manufacturing a bipedal walking robot.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to balance the center of gravity in the left-right direction without equipping a motor having a rotation axis in the traveling direction of the robot. It is an object of the present invention to provide a technique for realizing a simple, inexpensive bipedal walking robot.

[0006]

In order to solve this problem, two circumscribed planes are provided on the sole of the robot. The center circumscribed plane of the sole on the robot side is a circumscribed plane that is in contact with the floor surface when the robot is upright, and the circumscribed plane on the side of the robot side is a circumscribed plane inclined obliquely upward with respect to the floor surface when the robot is erect.

When the robot stands upright without walking, the lengths of both legs are aligned such that the circumscribed plane on the center side of the robot contacts the floor surface.

When the robot is caused to walk, first, before the free leg side is separated from the ground, the free leg is extended in the direction of the floor surface or the support leg is contracted in the direction opposite to the floor surface. The robot takes a posture such that the circumscribed plane on the side of the back robot contacts the floor, and moves the center of gravity of the robot to the support leg side.
Next, the free leg is stretched forward and landed on the floor before the robot falls over to the free leg side by moving the center of gravity due to the free leg being retracted and floating from the floor surface. Before floating the free leg, the support leg is in contact with the floor at the robot side circumscribed plane of the sole, so the entire robot is inclined to the support leg side, so there is a delay before the robot falls down to the free leg side. Therefore, it is possible to lift the free leg before landing, without falling the robot. By repeating this operation, biped walking can be realized.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The principle and one embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a view of a bipedal walking robot viewed from the front and front. 1 is a waist link and 2 is a right thigh link.
The waist link 1 and the right thigh link 2 can be changed in relative angle by the right waist motor 3 with the robot left-right direction as a rotation axis. 4 is a right shin link. The relative angle between the right thigh link 2 and the right shin link 4 can be changed by the right knee motor 5 with the robot left-right direction as the rotation axis. 6
Is the right foot link. The right shin link 4 and the right foot link 6
The right ankle motor 7 can change the relative angle with the robot left-right direction as the rotation axis. 8 is the right sole. Reference numeral 9 denotes a plane on the center of the robot on the right sole, which is in contact with the floor when the robot stands upright. Reference numeral 10 denotes a plane on the side of the robot on the right sole, which is inclined obliquely upward with respect to the floor when the robot stands upright. 11 is a left thigh link. The relative angle between the waist link 1 and the left thigh link 11 can be changed by the left waist motor 12 using the left-right direction of the robot as a rotation axis. 13 is a left shin link. The left thigh link 11 and the left shin link 13 are driven by the left knee motor 14
The relative angle can be changed with the robot left-right direction as a rotation axis. Reference numeral 15 denotes a left foot link. Left shin link 1
3 and the left foot link 15 can be changed in relative angle by the left ankle motor 16 with the robot left-right direction as the rotation axis. 17 is the left sole. Reference numeral 18 denotes a plane at the center of the robot on the left sole, which is in contact with the floor when the robot stands upright. Reference numeral 19 denotes a plane on the side of the robot on the left sole, which is inclined obliquely upward with respect to the floor when the robot stands upright.

FIG. 2 is a system configuration diagram showing the configuration of the control means of the bipedal walking robot.

The speed command input means 20 is a means for inputting a walking speed command from outside the robot. The walking speed command is input to the central control device 21. Central control unit 21
Calculates the angle to be taken by each motor in each control cycle and sends angle command data to the motor control means 22. The motor control means 22 determines the right waist motor 3, right knee motor 5, right ankle motor 7, left waist motor 12,
Control is performed so that the rotation angles of the left knee motor 14 and the left ankle motor 16 are the same as the angle command data.

Next, a control method for realizing the walking of the biped walking robot will be described with reference to FIG. 3, which schematically illustrates a state in which the biped walking robot walks.

The bipedal walking robot has the following six target postures.

The first target posture is a state where the right sole robot center-side circumscribed plane 9 and the left sole robot center-side circumscribed plane 18 are in contact with the floor. In the first target posture, the vertical distance from the waist link 1 to the right foot 8 is equal to the vertical distance from the waist link 1 to the left foot 17, and the center of gravity is realized so that the robot does not fall down in the front-back direction. In addition, the posture is such that the left sole 17 is located forward of the right sole 8 by a distance corresponding to the present step length.

The second target posture is a state in which the right sole 8 and the circumscribed plane 19 on the side surface of the left sole robot touch the floor and the robot is tilted to the left. In the second target posture, the relative positions of the left sole 17 and the right sole 8 in the front-rear direction are the same as those in the first target posture, and a center of gravity position such that the robot does not fall in the front-rear direction is realized. In addition, the vertical distance from the waist link 1 to the left sole 17 is shorter than the vertical distance from the waist link 1 to the right sole 8 such that the circumscribed plane 19 on the side of the left foot robot contacts the floor. Posture.

The third target posture is a state in which the circumscribed plane 19 on the side surface of the left sole robot is in contact with the floor and the right sole 8 is floating from the floor. In the third target posture, the right sole 8 and the left sole 1
7, the relative position in the front-rear direction is equalized, and the center of gravity position is set so that the robot does not fall down in the front-rear direction.
This is a posture in which the vertical distance from the waist link 1 to the right sole 8 is shorter than the vertical distance from the waist link 1 to the left sole 17 so as to float from the floor.

In the third target posture, the circumscribed plane 19 on the side surface of the left sole robot needs to have such an inclination that the robot does not fall to the left leg side due to the inertial force or the like during walking. In order to extend the time required for the robot to fall down to the right leg side, it is preferable that the robot is inclined to the left leg side as much as possible. It is assumed that the inclination of the robot side circumscribed plane 19 on the left sole is determined and implemented by experiment or calculation so as to satisfy such a condition.

In the third target posture, the entire robot is inclined leftward due to the inclination of the circumscribed plane 19 on the side of the left sole robot. Therefore, even when the right leg is lifted, the posture of the robot is relatively stably maintained.

The fourth target posture is a state where the right sole robot center-side circumscribed plane 9 and the left sole robot center-side circumscribed plane 18 are in contact with the floor. In the fourth target posture, the vertical distance from the waist link 1 to the right foot 8 is equal to the vertical distance from the waist link 1 to the left foot 17, and the center of gravity position is realized such that the robot does not fall down in the front-rear direction. In addition, the posture is such that the right sole 8 is located forward of the left sole 17 by a distance corresponding to the present step length.

The fifth target posture is a state in which the left sole 17 and the circumscribed plane 10 on the side surface of the right sole robot are on the floor and the robot is inclined rightward. In the fifth target posture, the relative positions of the left sole 17 and the right leg 8 in the front-rear direction are the same as those in the fourth target posture, and a center of gravity position that prevents the robot from falling in the front-rear direction is realized. In addition, the vertical distance from the waist link 1 to the right sole 8 is relatively shorter than the vertical distance from the waist link 1 to the left sole 17 so that the circumscribed plane 10 on the side surface of the right sole robot contacts the floor. Posture.

The sixth target posture is a state in which the circumscribed plane 10 on the side surface of the right sole robot is on the floor and the left sole 17 is floating from the floor. In the sixth target posture, the relative positions of the left sole 17 and the right sole 8 in the front-rear direction are equalized to realize a center of gravity position at which the robot does not fall in the front-rear direction, and the left sole 17 floats from the floor. In this posture, the vertical distance from the waist link 1 to the left sole 17 is shorter than the vertical distance from the waist link 1 to the right sole 8.

In the sixth target posture, the circumscribed plane 10 on the side surface of the right sole robot needs to have such an inclination that the robot does not fall to the right leg side due to the inertial force during walking. In order to extend the time required for the robot to fall to the left leg side, it is preferable that the robot is inclined to the right leg side as much as possible. It is assumed that the inclination of the circumscribed plane 10 on the side surface of the right sole robot side is determined by experiment or calculation so as to satisfy such a condition and is implemented.

In the sixth target posture, the entire robot is inclined rightward due to the inclination of the circumscribed plane 10 on the side surface of the right sole robot. Therefore, the posture of the robot can be relatively stably maintained even when the left leg is lifted.

When a speed command value is input from the speed command input means 20, the central controller 21 determines a step length to be taken by the robot. The range of the speed command value is, for example, an integer value of 0 or more and 16 or less.
For example, it is assumed that the length is proportionally increased according to the speed command value.

The initial posture of the robot is the first target posture and the stride length is 0.

The robot is in a first target posture,
While the stride determined by the central control device 21 is 0, the first target posture is maintained. When the robot is in the first target posture and the stride determined by the central control device 21 is not 0, the posture of the robot is changed to the second target posture within a predetermined period. When the robot reaches the second target posture, the posture of the robot is changed to the third target posture within a predetermined period. When the robot reaches the third target posture, the posture of the robot is changed to the fourth target posture within a predetermined period. When the robot reaches the fourth target posture, the posture of the robot is changed to the fifth target posture within a predetermined period. When the robot reaches the fifth target posture, the posture of the robot is changed to the sixth target posture within a predetermined period. Robot 6
Is reached, the posture of the robot is changed to the first target posture within a predetermined period.

By repeating this procedure, the robot can walk.

The period of the posture change to each target posture is as follows.
It is determined experimentally or by dynamic calculation so that the robot does not fall down while walking. Also,
The posture of the robot during the posture change process is, for example, a posture obtained by linearly interpolating the immediately preceding target posture and the current target posture.

In this embodiment, the robot having the motors at the waist and the knee is shown. However, the present invention can also be realized by making the link length from the waist to the soles variable by using a linear actuator. Is possible.

The sole structure may be such that two circumscribed planes are realized by a structure combining planes with steps as shown in the front view of FIG. The step-planar right sole 23 has a robot-side circumscribed plane 24 of the step-planar right sole and a robot center-side plane 25 of the step-planar right sole, and the step-planar left sole 26 has a step. There is a robot-side circumscribed plane 27 on the left side of the flat sole and a robot central-side plane 28 on the left sole of the stepped side. By using these circumscribed planes in the same manner as in the above-described embodiment, bipedal walking can be performed while keeping the posture balance in the left-right direction.

Further, as shown in the front view in FIG. 5, a curved structure having an infinite number of circumscribed planes may be used. The curved right sole 29 has a robot-side circumscribed plane 30 on the curved right sole and a robot central center plane 31 on the curved right sole, and the curved left sole 32 has a curved left sole. The robot has a circumscribed plane 33 on the side of the robot side and a plane 34 on the center of the robot on the left side of the curved surface. By using these circumscribed planes in the same manner as in the above-described embodiment, bipedal walking can be performed while keeping the posture balance in the left-right direction.

In this embodiment, the speed command input means 2
Although the walking operation by a human using 0 has been described, the present invention is also effective when performing autonomous walking in combination with an external measurement sensor such as a television camera.

[0034]

As described above, according to the present invention, without using a motor having a rotation axis in the anterior and posterior directions of the robot at the ankle and waist,
A simple and inexpensive bipedal walking robot can be realized.

[Brief description of the drawings]

FIG. 1 is a front view of a robot according to an embodiment of the present invention.

FIG. 2 is a system configuration diagram showing a configuration of a robot control unit in the present embodiment.

FIG. 3 is a schematic diagram for explaining a target posture of the robot and a transition of the target posture in the embodiment.

FIG. 4 is a diagram illustrating an excerpt of a sole portion of a step-type robot according to an embodiment of the present invention;

FIG. 5 is a diagram showing an excerpt of a sole portion of a curved robot according to an embodiment of the present invention.

[Explanation of symbols]

1 ... waist link, 2 ... right thigh link, 3 ... right waist motor, 4 ...
Right shin link, 5 ... Right knee motor, 6 ... Right foot link, 7 ... Right ankle motor, 8 ... Right sole, 9 ... Right sole robot center side plane, 10 ... Right sole robot side plane, 11 ... Left thigh Link, 12: Left waist motor, 13: Left shin link, 14 ...
Left knee motor, 15 ... left foot link, 16 ... left ankle motor,
17 ... left sole, 18 ... robot center side plane of left sole, 1
9: flat surface on the side of the robot on the left sole, 20: speed command input means, 21: central control device, 22: motor control means, 2
Reference numeral 3 denotes a step-flat right foot sole, 24 denotes a robot-side circumscribed plane of the step-flat right foot sole, 25 denotes a robot center-side plane of a step-flat right foot sole, 26 denotes a step-planar left foot sole, 27
… A circumscribed plane on the side of the robot on the left sole of the step plane type, 28
... Robot center side plane of left foot sole of stepped flat type, 29. Curved right foot sole, circumscribed plane of robot side surface of right foot sole of curved face, 31 ... Robot central side plane of right foot sole of curved type, 32. Curved left sole 33, circumscribed plane on left side of robot on left side of curved plane, 34 ... center plane on left side of robot on curved left sole.

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Claims (1)

[Claims] 1. A robot having a circumscribed plane at the center of the robot on the sole of the robot and in contact with the floor when the robot is upright, and an circumscribed plane inclined obliquely upward with respect to the floor when the robot is upright on the side of the robot on the sole of the robot. A bipedal walking robot having control means for controlling the posture of the robot such that a circumscribing plane suitable for maintaining a posture balance of the robot during walking is in contact with the floor surface.