Task Planning for Visual Room Rearrangement under Partial Observability

Abstract

This paper presents a novel hierarchical task planner under partial observability that empowers an embodied agent to use visual input to efficiently plan a sequence of actions for simultaneous object search and rearrangement in an untidy room, to achieve a desired tidy state. The paper introduces (i) a novel Search Network that utilizes commonsense knowledge from large language models to find unseen objects, (ii) a Deep RL network trained with proxy reward, along with (iii) a novel graph-based state representation to produce a scalable and effective planner that interleaves object search and rearrangement to minimize the number of steps taken and overall traversal of the agent, as well as to resolve blocked goal and swap cases, and (iv) a sample-efficient cluster-biased sampling for simultaneous training of the proxy reward network along with the Deep RL network. Furthermore, the paper presents new metrics and a benchmark dataset - RoPOR, to measure the effectiveness of rearrangement planning. Experimental results show that our method significantly outperforms the state-of-the-art rearrangement methods Weihs et al. (2021a); Gadre et al. (2022); Sarch et al. (2022); Ghosh et al. (2022).