APEX: Unsupervised, Object-Centric Scene Segmentation and Tracking for Robot Manipulation

TL;DR

APEX is a novel unsupervised object segmentation and tracking model that effectively handles complex scenes in robot manipulation, outperforming current methods and enabling improved robot skill execution.

Contribution

We introduce APEX, a new latent-variable model with a mask normalization algorithm and high-resolution encoder for better scene understanding in robotics.

Findings

APEX outperforms state-of-the-art in unsupervised segmentation and tracking.

APEX achieves high accuracy on real-world and simulated datasets.

Segmentations improve robot manipulation performance.

Abstract

Recent advances in unsupervised learning for object detection, segmentation, and tracking hold significant promise for applications in robotics. A common approach is to frame these tasks as inference in probabilistic latent-variable models. In this paper, however, we show that the current state-of-the-art struggles with visually complex scenes such as typically encountered in robot manipulation tasks. We propose APEX, a new latent-variable model which is able to segment and track objects in more realistic scenes featuring objects that vary widely in size and texture, including the robot arm itself. This is achieved by a principled mask normalisation algorithm and a high-resolution scene encoder. To evaluate our approach, we present results on the real-world Sketchy dataset. This dataset, however, does not contain ground truth masks and object IDs for a quantitative evaluation. We thus introduce the Panda Pushing Dataset (P2D) which shows a Panda arm interacting with objects on a table in simulation and which includes ground-truth segmentation masks and object IDs for tracking. In both cases, APEX comprehensively outperforms the current state-of-the-art in unsupervised object segmentation and tracking. We demonstrate the efficacy of our segmentations for robot skill execution on an object arrangement task, where we also achieve the best or comparable performance among all the baselines.