System for controlling locomotion of a walking robot having a sensor for detecting externally exerted forces

• US 5,513,106 A
• Filed: 11/22/1994
• Issued: 04/30/1996
• Est. Priority Date: 12/20/1991
• Status: Expired due to Term

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Yoshino, Ryutaro, Takahashi, Hideo
• Primary Examiner(s): Teska, Kevin J.
• Assistant Examiner(s): LOUIS JACQUES, JACQUES H
• Application Number:
  US08/343,206
• Time in Patent Office: 525 Days
• Field of Search: 364/424.02, 364/424.05, 364/424.01, 364/463, 180/8.1, 180/8.4, 180/8.6, 180/8.5, 318/568.1, 318/625, 318/568.12, 318/568.22, 318/568.11, 318/568.16, 901/1, 901/9, 395/95, 395/88, 395/80, 395/82, 395/84, 395/81, 395/96, 395/93, 36/28, 36/30 R, 36/65 A, 36/139
• US Class Current: 701/23
• CPC Class Codes: B62D 57/032 with alternately or sequentially lifted supporting base and legs; with alternately or sequentially lifted feet or skid B62D57/024 takes precedence

Abstract

A system for controlling the locomotion of a biped walking robot having a body and a pair of legs each connected to the body through a hip joint and having a knee joint and an ankle joint and a foot at its distal end in accordance with predetermined locomotion data including a foot landing position of a lifted leg. A 6-dimensional force and torque sensor is provided at the body to detect an external force exerted on the robot. A moment is calculated from the external force and integrated during the external force exists. A coefficient is further determined in accordance with the trajectory of the lifted leg and is multiplied to the integrated moment. The predetermined foot landing position is corrected in response to the product and control values for the associated drive joints are changed such that the lifted leg will land at the corrected position, whereby preventing the robot from losing its stability when the external force exerts on the robot.

Claims

1. A system for controlling the locomotion of a legged walking robot having a body link and articulated leg linkages each connected to the body link through a first joint and having at least a second joint of the type having:

actuator means for driving the joints; and

control means for determining a control value of the actuator means for each of the joints based on locomotion data including a landing position of a lifted leg linkage;

wherein the improvement comprises;

a cover supported by an external force sensor on the body link, with the force sensor linked to the control means, for detecting an external force exerted on the body link; and

said control means adjusts the control value for at least one of the joints of a lifted leg linkage in response to the detected external force to shift the landing position of the lifted leg linkage in a direction in which the external force acts.

6. A system according to claim 1, wherein said control means includes:

fourth means for determining a coefficient in accordance with the locomotion data; and

fifth means for correcting the landing position by an amount determined form a value obtained by multiplying the detected external force by the coefficient;

and said control means adjusts the control value such that the lifted leg linkage will land at the corrected position.

7. A system according to claim 1, wherein said control means includes:

sixth means for determining a moment acting on the body link from the detected external force;

seventh means for determining a coefficient in accordance with the locomotion data; and

eighth means for correcting the landing position by an amount determined form a value obtained by multiplying the determined moment by the coefficient;

and said control means adjusts the control value such that the lifted leg linkages will land at the corrected position.

8. A system according to claim 7, wherein said seventh means determines the coefficient in accordance with a trajectory of the lifted leg linkage.

9. A system according to claim 8, wherein said seventh means increases the coefficient with increasing proximity to the next landing.

10. A system according to claim 1, wherein said first means includes:

ninth means for detecting a position at which the external force is exerted;

tenth means for calculating a moment by multiplying the external force by a distance from a reference level to the position at which the external force is exerted; and

eleventh means for correcting the landing position of a lifted leg linkage by an amount in response to the calculated moment;

and said control means adjusts the control value such that the lifted leg linkage will land at the corrected position.

2. A system according to clam 1, wherein said control means includes:

first means for determining a moment acting on the body link from the detected external force; and

second means for correcting the landing position by an amount in response to the determined moment;

and said control means adjusts the control value such that the lifted leg linkage will land at the corrected position.

3. A system according to claim 2, wherein said second means increases the amount with increasing moment.

4. A system according to claim 2, wherein said control means includes:

third means for integrating the determined moment while the external force is exerted;

and said second means corrects the landing position by an amount in response to the integrated moment.

5. A system according to claim 4, wherein said second means increases the amount with increasing integrated moment.

11. A system for controlling the locomotion of a biped walking robot having a body link and a pair of articulated leg linkages each connected to the body link through a hip joint and having at least a second joint and a foot, including:

actuator means for driving the joints; and

controls means for determining a control value of the actuator means for each joint based on predetermined locomotion data including a foot landing position of a lifted leg linkage;

wherein the improvement comprises;

a plurality of sensors positioned on the body link and linked to the control means for detecting an external force exerted on the body link;

first means for determining a moment acting on the robot from the detected external force; and

second means for correcting the predetermined foot landing position from that in the locomotion data in a direction in which the external force acts by an amount in response to the determined moment;

and said control means adjusts the control value for at least one of the associated drive joints of the lifted leg linkage such that the lifted leg linkage'"'"'s foot lands at the corrected position.

12. A system according to claim 11, wherein said second means includes:

means for determining a coefficient in accordance with the trajectory of the lifted leg linkage in the predetermined locomotion data;

and said second means corrects the predetermined foot landing position by an amount in response to a value by multiplying the determined moment by the coefficient.

13. A system according to claim 11, wherein said plurality of sensors comprises a six-dimensional force and torque sensor.

14. A system according to claim 11, wherein said first means comprises of a memory for storing a position at which a detected force acts.

15. A system according to claim 11, wherein said first means determines the moment about the axis in the robot'"'"'s traveling direction or in the lateral direction thereto.

16. A system for controlling the walking movement of a robot having a body and a pair of legs connected to the body through hip joints, each leg having a knee joint and a foot, comprising:

motors for driving the hip joints and knee joints;

a controller for controlling the motors, based on walking data in a memory including a foot landing position of a lifted leg;

a detector linked to the controller for detecting an external force acting on the robot body; and

a foot landing position compensator, associated with the controller for determining a moment acting on the robot body resulting from the external force and for controlling the motors to shift the foot landing position of the foot of the lifted leg, in the direction in which the external force acts on the robot body, by an amount proportional to the product of an integrated value of the moment and a coefficient which increases as the leg approaches footfall.