ILSA: Incremental Learning for
Robot Shared Autonomy

In submission

1CMU, 2NIST, 3Pitt

Abstract

Shared autonomy holds promise for improving the usability and accessibility of assistive robotic arms, but current methods often rely on costly expert demonstrations and lack the ability to adapt post-deployment. This paper introduces ILSA, an Incrementally Learned Shared Autonomy framework that continually improves its assistive control policy through repeated user interactions. ILSA leverages synthetic kinematic trajectories for initial pretraining, reducing the need for expert demonstrations, and then incrementally finetunes its policy after each manipulation interaction, with mechanisms to balance new knowledge acquisition with existing knowledge retention during incremental learning. We validate ILSA for complex long-horizon tasks through a comprehensive ablation study and a user study with 20 participants, demonstrating its effectiveness and robustness in both quantitative performance and user-reported qualitative metrics.

Methodology

Our goal is to develop a function that maps the task state and user action to a robot action that is both task-optimal and aligned with the user's intent. While the function may be imperfect initially, it is designed to improve over times through continuous user interaction with the shared autonomy system.

Action Generation Model


Synthetic Kinematic Trajectory Generation


Finetuning Designs in the Incremental Learning Phase

Finetuning 1

Corrected Trajectory Generation

Finetuning 2

Layered Supervision

Finetuning 3

Partial Model Update

Human Study

We conducted a user study subject to a university-approved IRB protocol with 20 participants, none of whom reported having prior experience teleoperating robots.

In the first interactions, ILSA lacks the knowledge to avoid collisions, leading to objects hitting obstacles.

After just a few interactions, ILSA has learned effective collision avoidance, helping users complete tasks more smoothly.

Pure teleoperation


Statistical Analysis of both task completion times and user-reported metrics supports the following two hypotheses:
  • H1: ILSA supports faster robot manipulation task completion times and easier manipulator control as compared to pure teleoperation.
  • H2: ILSA improves task performance over time as a user repeatedly performs a task, in contrast to a static shared autonomy method.

Mean Task Completion Times
Median Likert Item Responses

BibTeX