Walking control apparatus of robot and method of controlling the same

• US 8,688,273 B2
• Filed: 01/12/2011
• Issued: 04/01/2014
• Est. Priority Date: 01/18/2010
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Ju Suk, Roh, Kyung Shik, Kwon, Woong
• Primary Examiner(s): Tran, Dalena
• Application Number:
  US13/005,262
• Publication Number:
  US 20110178637A1
• Time in Patent Office: 1,175 Days
• Field of Search: 700/245, 700/246, 700/251, 700/253, 700/260, 700/261, 318/568.1, 318/568.12, 318/568.16, 318/568.17, 318/568.2, 901/1, 901/9, 901/46
• US Class Current: 700/254
• CPC Class Codes: B25J 9/1648 non-linear control combined or not with linear control
• 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
• CPC Class Codes: G05B 2219/23289 State logic control, finite state, tasks, machine, fsm

Abstract

A walking control apparatus of a robot includes a joint portion provided in each of a plurality of legs of the robot, a pose sensing unit to sense the pose of the robot, a walking state determination unit to determine a walking state from the pose of the robot, a knot point compensation value calculator to determine a Center Of Mass (COM) of the robot from the pose of the robot and to calculate a knot point compensation value, a desired angle trajectory generator to generate a reference knot point of the joint portion corresponding to the walking state, to compensate for the reference knot point using the knot point compensation value so as to generate a desired knot point, and to generate a desired angle trajectory of the joint portion using the desired knot point. The knot point which is the angle command of the joint portion of each of the legs to perform the next step is compensated for based on the COM, and the compensated desired knot point is smoothly connected using the spline curve such that the robot walks similar to a human. In addition, in order to maintain balance while walking, the angle of the joint portion of the intermediate point of the current step is fed back and the knot point of the next step is predicted and adjusted, such that the robot stably and smoothly walks.

Claims

1. A walking control apparatus of a robot comprising:

a joint portion provided in each of a plurality of legs of the robot;

a pose sensing unit to sense the pose of the robot;

a walking state determination unit to determine a walking state from the pose of the robot;

a knot point compensation value calculator to determine a Center Of Mass (COM) of the robot from the pose of the robot and to calculate a knot point compensation value based on the COM and one or more reference values; and

a desired angle trajectory generator to generate a reference knot point of the joint portion corresponding to the walking state, to compensate for the reference knot point using the knot point compensation value to generate a desired knot point, and to generate a desired angle trajectory of the joint portion using the desired knot point.

2. The walking control apparatus according to claim 1, further comprising:

a torque calculator to calculate torque to follow the desired angle trajectory; and

a servo controller to output the torque to the joint portion and to control the walking of the robot.

3. The walking control apparatus according to claim 1, wherein the desired angle trajectory generator includes a spline generator to connect the desired knot point using a spline curve.

4. The walking control apparatus according to claim 1, wherein the knot point compensation value calculator determines an angular speed of a change in COM, compares the angular speed of the change in COM with a reference angular speed, and calculates the knot point compensation value.

5. The walking control apparatus according to claim 1, wherein the joint portion is a hip joint portion to move a thighbone portion of the robot.

6. The walking control apparatus according to claim 5, wherein the desired knot point is at least one of a desired roll angle and a desired pitch angle of the hip joint portion.

7. The walking control apparatus according to claim 1, wherein the walking state determination unit determines a stance leg which touches the ground and a swing leg which does not touch the ground.

8. The walking control apparatus according to claim 7, wherein the desired angle trajectory generator generates the reference knot point of the joint portion of each of the stance leg and the swing leg, compensates for the reference knot point using the knot point compensation value, and generates the desired angle trajectory of the joint portion of each of the support leg and the swing leg using the compensated knot point.

9. The walking control apparatus according to claim 7, wherein the desired angle trajectory generator generates the reference knot point of the joint portion of the swing leg, compensates for the reference knot point using the knot point compensation value, and generates the desired angle trajectory of the joint portion of the swing leg using the compensated knot point.

10. The walking control apparatus according to claim 1, wherein the desired angle trajectory generator comprises:

a support knot point compensator to compensate a reference knot point of the hip joint portion and generate a support knot point;

a swing knot point compensator to compensate a reference knot point of the hip joint portion and generate a swing knot point;

spline generators respectively to connect the desired knot points compensated for by the support knot point compensator and the swing knot point compensator using spline curves to generate a desired angle trajectory of the hip joint portion of each of the legs;

a switch to determine the stance leg and swing leg in correspondence with the walking state data (0 or

     1) of each leg transmitted from the walking state determination unit, and transmit support desired angle trajectory data to the stance leg to transmit swing desired angle trajectory data to the swing leg according to the determined result; and

the left leg angle trajectory generator to generate a left desired angle trajectory, which the hip joint portion of the left leg will follow, according to the desired angle data transmitted from the switch, and to transmit the left desired angle trajectory to the torque calculator.

11. A walking control apparatus of a robot comprising:

a joint portion provided in each of a plurality of legs of the robot;

a pose sensing unit to sense the pose of the robot;

a walking state determination unit to determine a walking state from the pose of the robot;

a knot point compensation value calculator to determine a Center Of Mass (COM) of the robot from the pose of the robot and to calculate a knot point compensation value; and

a desired angle trajectory generator to generate a reference knot point of the joint portion corresponding to the walking state, to compensate for the reference knot point using the knot point compensation value to generate a desired knot point, and to generate a desired angle trajectory of the joint portion using the desired knot point,

wherein the knot point compensation value calculator determines a distance of a change in COM in an X-axis direction, compares the determined distance of the change in COM with a reference distance, and calculates the knot point compensation value.

12. A walking control apparatus of a robot comprising:

a joint portion provided in each of a plurality of legs of the robot;

a pose sensing unit to sense the pose of the robot;

a walking state determination unit to determine a walking state from the pose of the robot;

a knot point compensation value calculator to determine a Center Of Mass (COM) of the robot from the pose of the robot and to calculate a knot point compensation value; and

a desired angle trajectory generator to generate a reference knot point of the joint portion corresponding to the walking state, to compensate for the reference knot point using the knot point compensation value to generate a desired knot point, and to generate a desired angle trajectory of the joint portion using the desired knot point,

wherein the knot point compensation value calculator determines a distance of a change in COM in a Y-axis direction, compares the determined distance of the change in COM with a reference distance, and calculates the knot point compensation value.

13. A walking control method of a robot comprising:

sensing a weight applied to a foot of the robot by way of a force/torque sensor;

determining a walking state of the robot using the sensed weight when the robot walks;

generating a reference knot point corresponding to the walking state of the robot;

sensing a Center Of Mass (COM) of the robot so as to calculate, by way of a knot point compensation value calculator, a knot point compensation value based on the COM and one or more reference values;

generating a desired knot point obtained by compensating for the reference knot point using the knot point compensation value; and

connecting the desired knot point so as to generate a desired angle trajectory of a joint portion provided in each leg of the robot.

14. The walking control method according to claim 13, further comprising:

calculating torque to follow the desired angle trajectory; and

generating and outputting a Pulse Width Modulation (PWM) signal corresponding to the torque to the joint portion of the robot.

15. The walking control method according to claim 13, wherein the generating of the desired angle trajectory includes connecting the desired knot point using a spline curve.

16. The walking control method according to claim 13, wherein the determining of the walking state includes:

sensing a weight applied to each foot of the robot;

determining that a leg to which the weight is applied is a stance leg which touches the ground; and

determining that a leg to which the weight is not applied is a swing leg which does not touch the ground.

17. The walking control method according to claim 16, wherein the calculating of the knot point compensation value includes:

determining an angular speed of the COM of an X-axis direction; and

comparing the determined angular speed of the COM of the X-axis direction with a reference angular speed so as to calculate the knot point compensation value.

18. The walking control method according to claim 17, wherein the generating of the desired angle trajectory includes generating a pitch desired angle trajectory of a hip joint portion provided in each leg of the robot.

19. The walking control method according to claim 18, wherein the generating of the desired angle trajectory includes generating a pitch desired angle trajectory of the hip joint portion provided in each of a stance leg and a swing leg of the robot.

20. The walking control method according to claim 13, further comprising:

calculating a knot point compensation value at a current step while the robot walks;

generating a reference knot point of a next step while the robot walks; and

compensating for the reference knot point of the next step to generate the desired angle trajectory of the joint portion of the next step.

21. A walking control method of a robot comprising:

sensing a weight applied to a foot of the robot by way of a force/torque sensor;

determining a walking state of the robot using the sensed weight when the robot walks;

generating a reference knot point corresponding to the walking state of the robot;

sensing a Center Of Mass (COM) of the robot so as to calculate, by way of a knot point compensation value calculator, a knot point compensation value based on the COM and one or more reference values;

generating a desired knot point obtained by compensating for the reference knot point using the knot point compensation value; and

connecting the desired knot point so as to generate a desired angle trajectory of a joint portion provided in each leg of the robot,

wherein the determining of the walking state includes;

sensing a weight applied to each foot of the robot;

determining that a leg to which the weight is applied is a stance leg which touches the ground; and

determining that a leg to which the weight is not applied is a swing leg which does not touch the ground, and

wherein the calculating of the knot point compensation value includes;

determining a distance of a change in COM in an X-axis direction;

comparing the determined distance of the change in COM in the X-axis direction with a reference distance of the X-axis direction so as to calculate a pitch knot point compensation value;

determining a distance of a change in COM in a Y-axis direction; and

comparing the determined distance of the change in COM in the Y-axis direction with a reference distance of the Y-axis direction so as to calculate a roll knot point compensation value.

22. The walking control method according to claim 21, wherein the generating of the desired angle trajectory includes:

generating a roll desired angle trajectory of a hip joint portion provided in each leg of the robot; and

generating a pitch desired angle trajectory of the hip joint portion provided in each leg of the robot.

23. The walking control method according to claim 22, wherein the generating of the desired angle trajectory includes generating a roll desired angle trajectory and a pitch desired angle trajectory of the hip joint portion provided in a swing leg of the robot.