Leg type mobile robot control apparatus

• US 6,243,623 B1
• Filed: 08/25/1999
• Issued: 06/05/2001
• Est. Priority Date: 01/31/1997
• 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: Matsumoto, Takashi, Takenaka, Toru, Hasegawa, Tadaaki
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): Marc, McDieunel, Marc, McDieunel
• Application Number:
  US09/331,587
• Time in Patent Office: 650 Days
• Field of Search: 700/245, 700/246, 700/251, 700/260, 700/247, 700/249, 700/253, 700/258, 700/250, 318/568.12, 318/568.22, 318/568.2, 318/568.17, 318/568.11, 318/568.1, 318/567, 180/8.1, 180/8.6, 701/23, 701/124, 901/1, 901/48, 901/46, 901/47, 901/2, 901/9, 901/33, 414/730, 414/734
• US Class Current: 700/245
• CPC Class Codes: B62D 57/02 with ground-engaging propulsion means, e.g. walking members
• 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

In a legged mobile robot, in particular in a biped robot, the feet position and/or posture is determined in such a manner that compensating moment of total floor reaction force about a desired total floor reaction force central point is determined, based upon the detected posture inclination of the robot, and is distributed to each of the feet such that each foot rotates respectively by predetermined angles about the desired total foot floor reaction force central point and a desired foot floor reaction force central point, in order to control the actual total floor reaction force and the actual foot floor reaction force acting on the robot properly such that it walks on a floor having not only a slope extending over a relatively long distance, but also existing locally. With this, it becomes possible to control the floor reaction force acting on the robot easily and properly, without causing any interference to occur. Moreover, the system can ensure to control the floor reaction force acting on the robot properly, even when walking on the floor having not only a slant or undulation extending over a relatively long distance. Furthermore, the system can achieve the posture stabilization control of a legged mobile robot easily, decrease the impact acting on the legged mobile robot at foot landing, and enhance the contactability with the floor so as to prevent the slippage or spinning at walking from happening. In addition, the system can decrease the load of the actuators of the legged mobile robot.

Claims

1. A system for controlling a legged mobile robot having at least a body and a plurality of legs each connected to the body through a first joint and having a foot connected to its distal end through a second joint, comprising:

a. gait generating means for generating a gait of the robot including at least a motion pattern including at least a desired position and a posture of the foot, and a desired pattern of a total floor reaction force acting on the robot;

b. desired foot floor reaction force central point determining means for determining a desired foot floor reaction force central point indicative of a point of action on the foot when the total floor reaction force in the generated gait is distributed to each of the feet;

c. actual floor reaction force detecting means for detecting an actual floor reaction force acting on the foot;

d. foot rotating amount determining means for calculating a moment of the detected actual floor reaction force about the desired foot floor reaction force central point, and for determining a foot rotating amount for rotating the foot based on the calculated moment;

e. foot position/posture correcting means for correcting the desired position and/or the posture of the foot such that the position and/or the posture of the foot rotates based on the determined foot rotating amount; and

f. joint displacement means for displacing the first joint and the second joint of the robot based on at least the corrected position and/or posture of the foot.

2. A system according to claim 1, wherein the foot position/posture correcting means corrects the desired position and/or the posture of the foot based on the determined foot rotating amount such that the position and/or the posture of the foot rotates about the desired foot floor reaction force central point or thereabout.

3. A system according to any of claims 1 to 2, further including:

g. foot moving amount determining means for determining at least one of a moment of total floor reaction force actually acting on the robot, and a moment obtained by subtracting a moment of the floor reaction force acting on the foot from the moment of total floor reaction force actually acting on the robot, and for determining a foot moving amount for moving the foot based on at least the determined moment;

and wherein the foot position/posture correcting means corrects the desired position and/or the posture of the foot based on the determined foot rotating amount and the determined foot moving amount.

4. A system according to claim 1 or 5, wherein the foot position/posture correcting means further corrects the desired position and/or the posture of the foot based on a posture error of the robot.

6. A system according to any of claims 1 or 5, wherein a compensating moment of total floor reaction force for posture stabilization is determined, and wherein the foot rotating amount determining means and/or the foot moving amount determining means determines the foot rotating amount and/or the foot moving amount based on at least the detected actual floor reaction force and the determined compensating moment of total floor reaction force for posture stabilization.

7. A system according to claim 6, wherein the compensating moment of total floor reaction force for posture stabilization is determined based on at least an inclination error of the robot.

8. A system according to claim 6, wherein the compensating moment of total floor reaction force for posture stabilization is determined based on at least a yaw-rate of the robot.

9. A system according to claim 6, wherein the compensating moment of total floor reaction force for posture stabilization is determined based on at least an error from a desired path of the robot.

10. A system according to claim 6, wherein a component of the compensating moment of total floor reaction for posture stabilization is set to zero or thereabout.

11. A system according to claim 6, wherein the foot rotating amount determining means and/or the foot moving amount determining means determines the foot rotating amount and/or the foot moving amount such that the compensating moment of total floor reaction force for posture stabilization is distributed to each of the legs.

5. A system for controlling a legged mobile robot having at least a body and a plurality of legs each connected to the body through a first joint and having a foot connected to its distal end through a second joint, comprising:

a. gait generating means for generating a gait of the robot including at least a motion pattern, including at least a desired position and a posture of the foot, and a desired pattern of a total floor reaction force acting on the robot;

b. desired foot floor reaction force central point determining means for determining a desired foot floor reaction force central point indicative of a point of action on the foot when the total floor reaction force in the generated gait is distributed to each of the feet;

c. actual floor reaction force detecting means for detecting an actual floor reaction force acting on the foot;

d. foot rotating amount determining means for determining a foot rotating amount for rotating the foot based on the detected actual floor reaction force;

e. foot position/posture correcting means for correcting the desired position and/or the posture of the foot such that the position and/or the posture of the foot rotates about the desired foot floor reaction force central point or thereabout based on the determined foot rotating amount; and

f. joint displacement means for displacing the first joint and the second joint of the robot based on at least the corrected position and/or posture of the foot.

12. A system for controlling a legged mobile robot having at least a body and a plurality of legs each connected to the body through a first joint and having a foot connected to its distal end through a second joint, comprising:

a. gait generating means for generating a gait of the robot including at least a motion pattern, including at least a desired position and a posture of the foot, and a desired trajectory pattern of a total floor reaction force acting on the robot;

b. posture stabilization compensating total floor reaction force calculating means for calculating a compensating total floor reaction force for stabilizing a posture of the robot;

c. actual floor reaction force detecting means for detecting an actual floor reaction force acting on the foot;

d. floor reaction force distributing means for distributing the total floor reaction force in the desired gait and the compensating total floor reaction force;

e. correcting means for correcting the desired position and/or the posture of the foot in the desired gait based on the distributed floor reaction force in the desired gait and the compensating floor reaction force and the detected floor reaction force acting on the foot; and

f. joint displacement means for displacing the first joint and the second joint of the robot based on at least the corrected position and/or posture of the foot.

13. A system according to claim 12, wherein the correcting means further corrects the desired position and/or the posture of the foot based on a posture error of the robot.