LERa: Replanning with Visual Feedback in Instruction Following

TL;DR

LERa is a visual feedback-based replanning method for robotics that improves task success rates by generating scene descriptions, explaining errors, and modifying plans using only RGB images and natural language instructions.

Contribution

LERa introduces a novel visual language model approach for replanning in robotics that requires minimal input and handles dynamic scene changes and failures effectively.

Findings

Achieves 40% improvement over baselines in dynamic environments.

Increases success rates by up to 67% in simulated tabletop tasks.

Proven effective in real-world robot experiments.

Abstract

Large Language Models are increasingly used in robotics for task planning, but their reliance on textual inputs limits their adaptability to real-world changes and failures. To address these challenges, we propose LERa - Look, Explain, Replan - a Visual Language Model-based replanning approach that utilizes visual feedback. Unlike existing methods, LERa requires only a raw RGB image, a natural language instruction, an initial task plan, and failure detection - without additional information such as object detection or predefined conditions that may be unavailable in a given scenario. The replanning process consists of three steps: (i) Look - where LERa generates a scene description and identifies errors; (ii) Explain - where it provides corrective guidance; and (iii) Replan - where it modifies the plan accordingly. LERa is adaptable to various agent architectures and can handle errors from both dynamic scene changes and task execution failures. We evaluate LERa on the newly introduced ALFRED-ChaOS and VirtualHome-ChaOS datasets, achieving a 40% improvement over baselines in dynamic environments. In tabletop manipulation tasks with a predefined probability of task failure within the PyBullet simulator, LERa improves success rates by up to 67%. Further experiments, including real-world trials with a tabletop manipulator robot, confirm LERa's effectiveness in replanning. We demonstrate that LERa is a robust and adaptable solution for error-aware task execution in robotics. The project page is available at https://lera-robo.github.io.