Method of generating poses and motions of a tree structure link system

• US 7,035,436 B2
• Filed: 08/06/2002
• Issued: 04/25/2006
• Est. Priority Date: 08/09/2001
• Status: Active Grant

• Current Assignee: University of Tokyo
• Original Assignee: University of Tokyo
• Inventors: Yamane, Katsu, Nakamura, Yoshihiko
• Primary Examiner(s): Wu, Jingge
• Assistant Examiner(s): Tabatabai, Abolfazl
• Application Number:
  US10/212,102
• Publication Number:
  US 20030034979A1
• Time in Patent Office: 1,358 Days
• Field of Search: 382/103, 382/107, 382/122, 345/473, 345/474, 345/475, 352/50, 352/87, 348/97, 348/154, 348/155, 348/208.1, 348/208.2, 348/208.4, 348/208.13, 348/208.16, 348/353, 348/407.1, 348/413.1, 348/451, 348/452, 348/699, 348/700, 901/8, 734/88, 73/17.9
• US Class Current: 382/107
• CPC Class Codes: G06T 13/40 of characters, e.g. humans, animals or virtual beings

Abstract

A method of generating poses and motions of a tree structure link system that is made by modeling of a man, animals, robots, etc., and consists of multiple links connected at joints, characterized in that by giving arbitrary numbers of constraint conditions to arbitrary numbers of arbitrary links, or by allowing adding or canceling the constraint conditions arbitrarily in the middle of the generation, the poses and the motions of the tree structure link system satisfying these constraint conditions are generated.

Claims

1. A method of generating poses and motions of a tree structure link system that is made by modeling of a man, animals, or robots, and consists of multiple links connected at joints, characterized in that by giving arbitrary numbers of constraint conditions to arbitrary numbers of arbitrary links, or by allowing adding or canceling the constraint conditions arbitrarily in the middle of the generation, the poses and the motions of the tree structure link system satisfying these constraint conditions are generated, the optimum pose is generated in consideration of all of the constraint conditions, and each priority is allocated to each constraint condition, the constraint condition having the high priority is satisfied strictly.

2. A method as claimed in claim 1, characterized in that the constraint conditions include the positions and poses of the links, and the velocities and angular velocities from which these change.

3. A method as claimed in claim 1, characterized in that the constraint conditions include that the joints do not exceed specified motion ranges respectively and the target velocity where the joint that exceeds a motion range returns within the motion range is considered one of the constraint conditions.

4. A method as claimed in claim 3, characterized in that the joints contain spherical joints with 3-degree of freedom, and the spherical joints are made not to exceed their motion ranges by using a method of expressing the motion ranges intuitively.

5. A method as claimed in claim 1, characterized in that the constraint conditions include that the joint value and the joint velocity of the joint with all or a part of degrees of freedom are approached the given target joint value and the given target joint velocity as much as possible and the target joint velocity is calculated based on an error from the target joint angle.

6. A method as claimed in claim 1, characterized in that the constraint conditions are realized by considering a restoring force depending on an error with an ideal state for each constraint condition.

7. A method as claimed in claim 1, characterized in that priorities are set to the constraint conditions respectively.

8. A method as claimed in claim 7, characterized in that an inverse kinetic calculation is used to generate the poses of the tree structure link system, the demand of strictness or the relief of strictness depending on the priority of the constraint conditions are permitted to the solution of the reverse kinematics calculation, and, a singular point low sensitivity motion decomposing method is used to solve the singular point problem of the solution.