Biologically Inspired Model for Timed Motion in Robotic Systems

TL;DR

This paper presents a biologically inspired motion model for robotic systems that achieves timed, smooth, and stable movements, demonstrated in simulation and real-world target interception tasks.

Contribution

It introduces a novel combination of a Hopf oscillator and an extended Kalman filter to generate and stabilize timed motions in robots, inspired by biological systems.

Findings

Successful implementation of isochronous movement in simulation and on physical robots

Effective target prediction using extended Kalman filter in dynamic environments

Robustness of the model against external disturbances demonstrated

Abstract

The goal of this work is the development of a motion model for sequentially timed movement actions in robotic systems under specific consideration of temporal stabilization, that is maintaining an approximately constant overall movement time (isochronous behavior). This is demonstrated both in simulation and on a physical robotic system for the task of intercepting a moving target in three-dimensional space. Motivated from humanoid motion, timing plays a vital role to generate a naturalistic behavior in interaction with the dynamic environment as well as adaptively planning and executing action sequences on-line. In biological systems, many of the physiological and anatomical functions follow a particular level of periodicity and stabilization, which exhibit a certain extent of resilience against external disturbances. A main aspect thereof is stabilizing movement timing against limited perturbations. Especially human arm movement, namely when it is tasked to reach a certain goal point, pose or configuration, shows a stabilizing behavior. This work incorporates the utilization of an extended Kalman filter (EKF) which was implemented to predict the target position while coping with non-linear system dynamics. The periodicity and temporal stabilization in biological systems was artificially generated by a Hopf oscillator, yielding a sinusoidal velocity profile for smooth and repeatable motion.