Planning motion patterns of human figures using a multi-layered grid and the dynamics filter

This paper presents a practical motion planner for humanoids and animated human figures. Modeling human motions as a sum of rigid body and cyclic motions, we identify body postures that represent the rigid-body part of typical motion patterns. This leads to a model of the configuration space that consists of a multi-layered grid, each layer corresponding to a single posture. A global search through this reduced configuration space yields a feasible path and the corresponding postures along the path. A velocity profile is calculated along the optimal path, subject to the speed and acceleration limits assumed for each posture. Cyclic motions, generated from "primitive" cyclic motion patterns for each posture, are then added to the trajectory produced by the path planner. This "kinematic" motion is then modified by the dynamics filter to result in dynamically consistent behavior. Examples are presented which demonstrate the use of this planner in an office environment.