Vision-Language Model-based Physical Reasoning for Robot Liquid Perception
Wenqiang Lai, Yuan Gao, Tin Lun Lam
TL;DR
This work demonstrates a novel action–reasoning paradigm that grounds a vision–language model (GPT-4V) in physical world feedback to perceive and recognize liquids through interactive multimodal perception. By combining Look and Shake actions with image-based perception and haptic feedback, the approach enables GPT-4V to qualitatively estimate viscosity and perform liquid recognition across varied containers without training. The method achieves 86.0% recognition accuracy, surpassing a vision-only baseline of 69.0%, and highlights the value of integrating physical knowledge into LVLM-driven robotic reasoning. The findings suggest practical implications for deploying LVLMs as embodied reasoning agents and point to future work in validating multiple LVLMs and expanding to additional perceptual modalities.
Abstract
There is a growing interest in applying large language models (LLMs) in robotic tasks, due to their remarkable reasoning ability and extensive knowledge learned from vast training corpora. Grounding LLMs in the physical world remains an open challenge as they can only process textual input. Recent advancements in large vision-language models (LVLMs) have enabled a more comprehensive understanding of the physical world by incorporating visual input, which provides richer contextual information than language alone. In this work, we proposed a novel paradigm that leveraged GPT-4V(ision), the state-of-the-art LVLM by OpenAI, to enable embodied agents to perceive liquid objects via image-based environmental feedback. Specifically, we exploited the physical understanding of GPT-4V to interpret the visual representation (e.g., time-series plot) of non-visual feedback (e.g., F/T sensor data), indirectly enabling multimodal perception beyond vision and language using images as proxies. We evaluated our method using 10 common household liquids with containers of various geometry and material. Without any training or fine-tuning, we demonstrated that our method can enable the robot to indirectly perceive the physical response of liquids and estimate their viscosity. We also showed that by jointly reasoning over the visual and physical attributes learned through interactions, our method could recognize liquid objects in the absence of strong visual cues (e.g., container labels with legible text or symbols), increasing the accuracy from 69.0% -- achieved by the best-performing vision-only variant -- to 86.0%.
