Robot motion emergence based on
attractor design

1. Attractor based robot control

Robots are stabilized by a feedback controller and robot motion is realized by giving a reference motion pattern to the colosed loop system. On the other hand, consider the robot dynamics as;

A cyclic robot motion draws a closed curved line in the state space. In this research, we design a nonlinear feedback controller

so that the state variable is entrained to the closed curved line as shown in the following figure. Based on our method, the robot yields motion autonomously without reference motion pattern, which means the robot motion is emerged by the interaction between robot body dynamics, control algorithm and its environments. The following movie shows an experimental result of a tap dancing robot.

2. Robot-robot communication based on attractor design

Attractor design method is employed for two robots, and the controllers are changed as;

motion synchronization is realized as shown in the follwing movies.
without communication with communication
After the human practices his dance by himself, he synchronizes with a dance partners, which is an implicit communication of human. The above results realizes this type of communication by an entrainment phenomenon.

3. Pseudo-reference for motion transfer

The following figure shows a successive image of a long jump. We sometimes use comments as "(a) run as if you climb stairs" or "(b) throw up your head and foot".
These sentences will be imaged by the above figure, however, it is difficult for beginners to image these posture because they include expert's instinct. In this research,
  1. Human motion obtained from motion capture system is modeled by an attractor.
  2. Based on the obtained controller, a virtual refrence posture is obtained by;
The virtual reference posture is pseudo-reference to realize the reference motion from dynamical point of view, which enables motion transfer.


e-mail : @mep.titech.ac.jp