Shengli Zhou
Publications
Scalable Object Relation Encoding for Better 3D Spatial Reasoning in Large Language Models
Spatial reasoning focuses on locating target objects based on spatial relations in 3D scenes, which plays a crucial role in developing intelligent embodied agents. Due to the limited availability of 3D scene-language paired data, it is challenging to train models with strong reasoning ability from scratch. Previous approaches have attempted to inject 3D scene representations into the input space of Large Language Models (LLMs) and leverage the pretrained comprehension and reasoning abilities for spatial reasoning. However, models encoding absolute positions struggle to extract spatial relations from prematurely fused features, while methods explicitly encoding all spatial relations (which is quadratic in the number of objects) as input tokens suffer from poor scalability. To address these limitations, we propose QuatRoPE, a novel positional embedding method with an input length that is linear to the number of objects, and explicitly calculates pairwise spatial relations through the dot product in attention layers. QuatRoPE's holistic vector encoding of 3D coordinates guarantees a high degree of spatial consistency, maintaining fidelity to the scene's geometric integrity. Additionally, we introduce the Isolated Gated RoPE Extension (IGRE), which effectively limits QuatRoPE's influence to object-related tokens, thereby minimizing interference with the LLM's existing positional embeddings and maintaining the LLM's original capabilities. Extensive experiments demonstrate the effectiveness of our approaches. The code and data are available at https://github.com/oceanflowlab/QuatRoPE.
$\mathcal{P}^3$: Toward Versatile Embodied Agents
Embodied agents have demonstrated promising capabilities in interacting with physical environments. Yet, versatile embodied agents face three core bottlenecks: dynamic environmental perception, open tool access, and complex multi-task planning. Prior methods depend entirely on tool feedback to track scene changes and task progress, leading to poor real-time adaptability, error accumulation, and limited tool compatibility; multi-task scheduling is also understudied due to the difficulty of handling task dependencies and conflicting priorities. To address these limitations, we propose $\mathcal P^3$, a unified framework integrating real-time perception and dynamic scheduling, which perceives task-relevant information actively from the environment, plugs and utilizes tools without feedback requirements, and plans multi-task execution by prioritizing urgent tasks and dynamically adjusting task order based on dependencies. We additionally build the Active Task Perception (ATP) benchmark to quantitatively measure VLMs' capacity for active scene understanding and task proposal. Evaluations on the ATP benchmark verify that multiple VLMs can detect and propose active tasks, and comprehensive real-world robot experiments prove our method bridges the gap between benchmarks and practical deployment, yielding transferable general-purpose embodied agents. Code and data are available at https://github.com/fz-zsl/P3.