Semantic Skill Grounding for Embodied Instruction-Following in Cross-Domain Environments
This addresses a domain-specific problem for embodied AI by improving skill transferability across environments, though it appears incremental as it builds on existing LM-based planning methods.
The paper tackles the challenge of grounding pretrained skills in cross-domain embodied instruction-following by proposing a semantic skill grounding framework that uses hierarchical skill decomposition and language model reasoning, achieving efficacy in 300 scenarios in the VirtualHome benchmark.
In embodied instruction-following (EIF), the integration of pretrained language models (LMs) as task planners emerges as a significant branch, where tasks are planned at the skill level by prompting LMs with pretrained skills and user instructions. However, grounding these pretrained skills in different domains remains challenging due to their intricate entanglement with the domain-specific knowledge. To address this challenge, we present a semantic skill grounding (SemGro) framework that leverages the hierarchical nature of semantic skills. SemGro recognizes the broad spectrum of these skills, ranging from short-horizon low-semantic skills that are universally applicable across domains to long-horizon rich-semantic skills that are highly specialized and tailored for particular domains. The framework employs an iterative skill decomposition approach, starting from the higher levels of semantic skill hierarchy and then moving downwards, so as to ground each planned skill to an executable level within the target domain. To do so, we use the reasoning capabilities of LMs for composing and decomposing semantic skills, as well as their multi-modal extension for assessing the skill feasibility in the target domain. Our experiments in the VirtualHome benchmark show the efficacy of SemGro in 300 cross-domain EIF scenarios.