JP2004188505A - Biped walking robot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a biped walking robot, which consumes only a small quantity of power in a battery, and operates for a long time. <P>SOLUTION: The biped walking robot 1 comprises an upper body 2, and two leg elements 3, which are connected with the upper body 2 by means of a waist articulation 8 and has a knee articulation 9 and an ankle articulation 10, and takes a standing attitude with the knee articulation 9 bending. The center of gravity of the whole of the robot is arranged so as to come to the position between the vertical line, which connects the ankle articulation 10 with the waist articulation 8 in the standing attitude, and the vertical line, which passes through the middle point between the vertical line connecting the ankle articulation 10 with the waist articulation 8 and the vertical line passing through the knee articulation 9. By this configuration, the driving torque of an actuator is reduced, and also the power consumption is reduced. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a bipedal walking robot that takes a standing posture with a knee joint bent.
[0002]
[Prior art]
In a conventional bipedal walking robot, the center of gravity of the entire robot is arranged almost directly above the knee joint when the knee joint is in an upright posture to reduce the burden on the knee joint (for example, see Patent Document 1). .).
[0003]
[Patent Document 1]
JP-A-2002-154078 (page 6 [0047]
(FIG. 2)
[0004]
[Problems to be solved by the invention]
However, in the above-described conventional technology, since the center of gravity of the entire robot is placed immediately above the knee joint for the purpose of reducing the burden on the knee joint, a large moment is applied to the waist joint and the ankle joint. There is a problem that a large amount of power is consumed by a battery mounted on the robot in order to cause the robot to walk, and as a result, the walking time of the robot, that is, the operating time is shortened.
[0005]
The present invention has been made to solve the above problems, and has as its object to provide a bipedal walking robot capable of operating for a long time.
[0006]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention comprises an upper body and two legs connected to the upper body by a hip joint and having a knee joint and an ankle joint, and the standing posture in which the knee joint is bent In the bipedal walking robot, in the standing posture, the center of gravity of the entire robot is arranged between a vertical line connecting the ankle joint and the waist joint and a central vertical line between the vertical line and the knee joint. It is characterized by having done.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a bipedal walking robot according to the present invention will be described with reference to the drawings.
FIG. 1 is a side view showing an embodiment of the present invention, and FIG. 2 is a front view thereof.
1 and 2, reference numeral 1 denotes a bipedal walking robot, which is a humanoid robot.
[0008]
Reference numeral 2 denotes an upper body of the bipedal walking robot 1, which includes a body 3, a head 4, and a pair of arms 5.
Reference numeral 6 denotes a power storage device such as a battery, which is stored inside the body 3 and is configured to be rechargeable from the outside of the bipedal walking robot 1. Actuators such as an electric motor for operating each unit and a control for controlling them are provided. Provides power for operation of the unit.
[0009]
Reference numeral 7 denotes legs, which are provided as a pair below the upper body, and are flexibly connected to the body 3 by a waist joint 8 driven by an actuator such as an electric motor.
Reference numeral 9 denotes a knee joint, which connects the thigh 7a and the lower leg 7b of the leg 7 so as to be able to flex and extend, and is driven by an actuator such as an electric motor.
Reference numeral 10 denotes an ankle joint, which connects the lower leg 7b and the foot 11 in a bendable manner and is driven by an actuator such as an electric motor.
[0010]
Note that the bipedal walking robot 1 of the present embodiment has a knee joint 9 in the front direction shown in FIG. 1 which is orthogonal to the direction in which the pair of legs 7 arranged in the front view shown in FIG. He is standing upright.
In this case, the upper body 2 is in a state in which all parts are extended in the vertical direction of the floor on which the bipedal walking robot 1 stands.
[0011]
The operation of the above configuration will be described.
FIG. 3 is an explanatory view showing the positional relationship of the center of gravity of the embodiment, and FIG. 4 is an explanatory view showing the position of the center of gravity at the time of minimum power consumption.
In FIG. 3, the center of gravity A of the entire robot on which the force F due to the total weight of the bipedal walking robot 1 acts is located on the upper body 2 in the standing posture of the bipedal walking robot 1, and the ankle joint 10 and the waist joint 8 are connected to each other. It is located at a distance S away from the connecting vertical line in the forward direction.
[0012]
At this time, assuming that the distance between the vertical line of the knee joint 9, the ankle joint 10, and the hip joint 8 bent forward is L, the total moment T acting on the leg 7 is the moment acting on the hip joint 8. Is FS, the knee joint 9 is F (LS), and the ankle joint 10 is FS,
T = FS + F (LS) + FS
= F (L + S) (1)
Is represented by
[0013]
Further, assuming that the power consumption required to hold the moment of FL at this time is W, the total power consumption P for maintaining the leg 7 in the standing posture is:
P = W (L + S) / L (2)
Is represented by
Therefore, as can be seen from the equations (1) and (2), when S = L, that is, when the center of gravity A is immediately above the knee joint 9, the total moment T and the total power consumption P become maximum, and T = 2F L, P = 2W.
[0014]
Further, when S = 0, that is, when the center of gravity A is immediately above the hip joint 8 and the ankle joint 10, the total moment T and the total power consumption P are minimized, and T = FL and P = W. Thus, the total moment T and the total power consumption P of 50% when the center of gravity A is right above the knee joint 9 are obtained.
Further, when S = L / 2, that is, the center of gravity A passes through a vertical line connecting the waist joint 8 and the ankle joint 10 and a vertical line extending from the knee joint 9 to the vertical line (hereinafter, central vertical line). ), The total moment T and the total power consumption P are 75% of T = 3FL / 2, P = 3W / 2, and the center of gravity A is just above the knee joint 9. Is the total moment T and the total power consumption P.
[0015]
This means that when the center of gravity A is between the vertical line connecting the waist joint 8 and the ankle joint 10 and the center vertical line, that is, when the center of gravity A is on the side of the waist joint 8 including the central vertical line, the total moment T and the total power consumption P indicate that the center of gravity A is 75% or less of that immediately above the knee joint 9.
That is, when the center of gravity A of the entire robot is located during this time, the holding force and the power consumption of the actuator for holding the legs 7 in the standing posture are 75% or less of that when the center of gravity A is directly above the knee joint 9. This indicates that the driving torque and power consumption of the actuator required for walking are also reduced.
[0016]
As described above, in the present embodiment, in the standing posture of the bipedal walking robot, the center of gravity of the entire robot is disposed between the vertical line connecting the waist joint and the ankle joint and the central vertical line, thereby reducing the waist. The holding force of the joint and ankle joint actuators can be reduced, and the power consumption of the robot as a whole can be reduced. Therefore, the actuator can be made smaller, lighter, and the operating time can be longer.
[0017]
In addition, by placing the center of gravity of the entire robot almost directly above the vertical line connecting the waist joint and the ankle joint in the standing posture of the bipedal walking robot, the holding force of the actuator of the waist joint and the ankle joint and the consumption of the robot as a whole Power can be minimized, the actuator can be made smaller and lighter, and the operating time can be made longer.
[0018]
The above effects have been described for the case where the present invention is applied to a biped walking robot using the same power storage device as the conventional example.However, when the effects of the present invention are directed to miniaturization of the power storage device, The weight reduction of the entire robot can be achieved by miniaturization, and the effect of reducing the weight can be further enhanced by reducing the size and weight of the actuator of each part of the robot. It is possible to provide a bipedal walking robot which is small and can be operated for a long time.
[0019]
In the above embodiment, the case where the present invention is applied to a bipedal walking robot has been described. However, the present invention is not limited to a bipedal walking robot, and can be applied to a multipedal robot. If the concept of the center of gravity arrangement of the present invention is applied to the present invention, the effects of prolonged operation time and downsizing of the power storage device can be similarly obtained.
[0020]
【The invention's effect】
As described above, the present invention, in the standing posture of a bipedal walking robot, by placing the center of gravity of the entire robot between the vertical line connecting the waist joint and the ankle joint and the central vertical line, the waist joint It is possible to reduce the holding force of the actuator of the ankle joint and reduce the power consumption of the entire robot, and it is possible to reduce the size and weight of the actuator and to increase the operating time.
[Brief description of the drawings]
FIG. 1 is a side view showing an embodiment of the present invention. FIG. 2 is a front view showing an embodiment of the present invention. FIG. 3 is an explanatory view showing the positional relationship of the center of gravity of the embodiment. Explanatory diagram showing the position of the center of gravity at the time of the minimum power consumption of the form.
DESCRIPTION OF SYMBOLS 1 Biped robot 2 Upper body 3 Torso 4 Head 5 Arm 6 Power storage device 7 Leg 7a Thigh 7b Lower leg 8 Waist joint 9 Knee joint 10 Ankle joint 11 Foot part

Claims (2)

A biped walking robot having an upper body and two legs connected to the upper body by a waist joint and having a knee joint and an ankle joint, and taking a standing posture in which the knee joint is bent;
In the standing posture, the center of gravity of the entire robot is arranged between a vertical line connecting the ankle joint and the waist joint and a center vertical line between the vertical line and the knee joint. Walking robot. In claim 1,
A bipedal walking robot wherein the center of gravity of the entire robot is arranged substantially directly above the ankle joint and the waist joint in the standing posture.

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