Human-Robot Skill Transfer with Enhanced Compliance via Dynamic Movement Primitives

TL;DR

This paper presents a systematic method to extract dynamic features from human demonstrations to auto-tune Dynamic Movement Primitives, enhancing robot skill transfer, compliance, and efficiency in learning from demonstrations and reinforcement learning.

Contribution

It introduces a novel approach for automatic parameter tuning in DMP using dynamic feature extraction from human demonstrations, improving robot adaptability and human-likeness.

Findings

Enhanced robot compliance and stability in trajectory reproduction.

Achieved human-like motion accuracy comparable to heuristic tuning.

Facilitated efficient skill transfer in both LfD and RL frameworks.

Abstract

Finding an efficient way to adapt robot trajectory is a priority to improve overall performance of robots. One approach for trajectory planning is through transferring human-like skills to robots by Learning from Demonstrations (LfD). The human demonstration is considered the target motion to mimic. However, human motion is typically optimal for human embodiment but not for robots because of the differences between human biomechanics and robot dynamics. The Dynamic Movement Primitives (DMP) framework is a viable solution for this limitation of LfD, but it requires tuning the second-order dynamics in the formulation. Our contribution is introducing a systematic method to extract the dynamic features from human demonstration to auto-tune the parameters in the DMP framework. In addition to its use with LfD, another utility of the proposed method is that it can readily be used in conjunction with Reinforcement Learning (RL) for robot training. In this way, the extracted features facilitate the transfer of human skills by allowing the robot to explore the possible trajectories more efficiently and increasing robot compliance significantly. We introduced a methodology to extract the dynamic features from multiple trajectories based on the optimization of human-likeness and similarity in the parametric space. Our method was implemented into an actual human-robot setup to extract human dynamic features and used to regenerate the robot trajectories following both LfD and RL with DMP. It resulted in a stable performance of the robot, maintaining a high degree of human-likeness based on accumulated distance error as good as the best heuristic tuning.