| US 7,490,012 B2 | ||
| Body dynamics calculation method, body dynamics model and model data thereof, and body-model generation method | ||
| Yoshihiko Nakamura, Tokyo (Japan); Katsu Yamane, Saitama (Japan); Ichiro Suzuki, Tokyo (Japan); Kazutaka Kurihara, Tokyo (Japan); and Koji Tatani, Kanagawa (Japan) | ||
| Assigned to Japan Science and Technology Agency, (Japan) | ||
| Appl. No. 10/515,019 PCT Filed May 21, 2003, PCT No. PCT/JP03/06344 § 371(c)(1), (2), (4) Date Aug. 30, 2005, PCT Pub. No. WO03/099119, PCT Pub. Date Dec. 04, 2003. |
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| Claims priority of application No. 2002-154853 (JP), filed on May 29, 2002; and application No. 2002-165234 (JP), filed on Jun. 06, 2002. | ||
| Prior Publication US 2006/0100818 A1, May 11, 2006 | ||
| Int. Cl. G01L 1/00 (2006.01) | ||
| U.S. Cl. 702—41 | 6 Claims |
| 1. A dynamics calculation method for muscles, tendons, ligamenta, and a skeleton, for calculating, in a body model defined
by data for rigid links expressing a skeleton and data for wires and virtual links expressing muscles, tendons, and ligamenta,
forces applied to or generated by the wires and virtual links from acceleration given to the rigid links, said the body dynamics
model which is expressed by data for wires and virtual links connected between the wires which express muscles, tendons, and
ligamenta of a body which includes a human body, a living body, or an animal body, and data for rigid links which express
bones,
wherein the rigid links are coupled by joints which express joints having a plurality of degrees of freedom to form a skeleton;
the wires connect origins and end points secured to predetermined locations of the bones expressed by the rigid links, pass
through no or one or more via-points which allow sliding and are secured to bones, and are formed such that the lengths and
tension of the wires can be changed according to the movement of the rigid links;
the virtual links are formed such that the origins and end points of a plurality of the wires are secured; and
forces applied to the wires and the virtual links, the lengths of the wires, and the motion of the rigid links interact with
each other,
the dynamics calculation method comprising:
a step of reading model data which includes the shapes and dynamics data of the wires and virtual links and the rigid links
for which dynamics calculation is performed, from a model-data file by a processing section;
a step of reading the current angles, positions, and velocities of the rigid links from a rigid-link file having stored the
angles, positions, and velocities of the rigid links, and also of reading acceleration given to the rigid links from an acceleration
file, by the processing section;
a step of calculating a Jacobian JL for the joint angle of the length of each wire according to the model data and the angles, positions, and velocities of the
rigid links, by the processing section;
a step of calculating generalized forces τG serving as forces at the connection points of the rigid links, required for generating motion caused by the acceleration given
to the rigid links, according to the acceleration of the rigid links read from the acceleration file and the angles and velocities
read from the rigid-link file, by the processing section;
a step of storing the obtained generalized forces τG in a generalized-force file, by the processing section;
a step of solving the following equation for f according to the previously obtained JL to obtain the generation forces f applied to each wire and virtual link from the generalized forces τG, by the processing section;
τG=JLtf
a step of storing the obtained rigid-link generation forces f in a generation-force file; and
wherein, T denotes transposed matrix or transposed vector.
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