Video

Abstract

Effectively integrating diverse sensory representations is crucial for robust robotic manipulation. However, the typical approach of feature concatenation is often suboptimal: dominant modalities such as vision can overwhelm sparse but critical signals like touch in contact-rich tasks, and monolithic architectures cannot flexibly incorporate new or missing modalities without retraining. Our method factorizes the policy into a set of diffusion models, each specialized for a single representation (e.g., vision or touch), and employs a router network that learns consensus weights to adaptively combine their contributions, enabling incremental integration of new representations. We evaluate our approach on real-world tasks such as occluded object picking, in-hand spoon reorientation, and puzzle insertion, as well as simulated manipulation tasks in RLBench, where it significantly outperforms feature-concatenation baselines on scenarios requiring multimodal reasoning. Our policy further demonstrates robustness to physical perturbations and sensor corruption. We further conduct perturbation-based importance analysis, which reveals adaptive shifts between modalities, for example transitioning from vision to multi-model when entering occluded spaces.

Perturbation-based importance analysis of representation importance across task stages

Policy robustness under physical perturbations or sensor corruptions

The following videos has been X4 accelerated

Runtime Perturbation
Object Repositioning
Sensor Corruption
Puzzle Perturbation
Repositioning + Sensor Corruption

Composing independently trained policies without retraining

The following videos has been X4 accelerated

RGB Only → Task Fail
Compose RGB and Tactile → Task Success

Occasional Failures of Our Policy Under Sensor Corruptions

The following videos has been X4 accelerated

Get stuck in the bag
Can't place spoon in target location