An effective implementation of agent's complex actions by reusing primitive motions

The efficient implementation of various physical actions of an agent to respond to dynamically changing situations is essential for the design of a realistic agent in a cyber world. To achieve a maximum diversity in actions, we develop a mechanism that allows composite actions to be constructed by reusing a set of primitive motions and enables an agent to instantly react to changes in the ambient states. Specifically we model an agent's body in terms of joints, and a primitive or composite motion is performed in a real time. To implement this mechanism, we produce an animation for each basic joint movement and develop a scheme to construct overall motions out of the primitive motions. These motions can be assembled into a plan by which an agent can achieve a goal. In this manner, diverse actions can be implemented without excessive efforts. This approach has conspicuous advantages when constructing a parallel action, e.g., eating while walking, that is, two or more parallel actions can be naturally merged into a parallel action with an arbitration on their priority. We implemented several composite and parallel actions to demonstrate the viability of our approach.