PhysVLMM: Interaction-Conditioned Physical Belief Maps for Articulated Objects in Robot Scene Maps

Open-vocabulary 3D maps let robots answer language queries about what and where, but they assume a static world and cannot answer queries about how scene elements behave. We introduce Vision-Language-Motion Maps (VLMM), an open-vocabulary, language-queryable 3D map - queried through a rule-based intent router over open-vocabulary object nouns, not a general natural-language interface - in which each element carries a fused motion attribute: a VLM/LLM semantic movability prior combined with geometrically observed cross-frame motion, together with a per-element uncertainty. Queries reduce to attribute filters that distinguish what has been seen to move, what could move but has not, and what stays still. On a controlled simulator benchmark with exact ground truth (AI2-THOR, three scene types) we show through ablation that the schema fields are non-substitutable: a semantic-only baseline fails motion queries even with strong features, and neither motion field substitutes for the other (the prior cannot answer "what is moving," observed motion cannot answer "what could move"). On real dynamic RGB-D (TUM and Bonn, six sequences) we show the uncertainty channel - our key difference from prior fused-motion work - consistently improves moving-vs-static average precision and reduces false motion flags, and that it is robust to estimated (noisy) poses. The raw confidence is not calibrated, but post-hoc isotonic calibration reaches an expected calibration error of 0.10. VLMM is a representation contribution: the closest prior maps each lack at least one of the four properties - open-vocabulary, language-queryable, fused prior-and-observed motion, and per-element uncertainty - that our combination provides.

A robot in a home it has never seen must open doors, drawers, lids and taps whose physics a picture does not show. Instructions such as "open the drawer halfway, gently" depend on that physics: how far a part travels, how it resists, and what locks it. We present Open-World Law-to-Action (L2A). A vision-language model (VLM) proposes, for each movable part, its motions, the terms of its law of motion, and what may lock it. Each proposal becomes a prior with a floor, so that touch can always overturn it. The robot identifies each part's law online by Bayesian linear regression with closed-form evidence, for parts that move in one way or in two, and keeps a hypothesis that an unseen part or motion locks the target. We prove that touch alone cannot rule this hypothesis out, derive when another look is worth its cost, and show that a constant load and friction cannot be told apart while a part moves one way. All experiments are in simulation, developed on some scenes and run once on held-out ones. In new kitchens the robot completes 80% of tasks from the VLM's proposals, against 98% when every part is known. Proposed physics raises success on objects that need new terms from 353 to 378-383 of 400 episodes, and a second look raises success in mixed scenes from 284 to 329 of 366 tasks. A mobile robot that takes nothing from the simulator completes 70 of 100 requests in new scenes, against 62 when the simulator says which part each box is (after one change made between two held-out tests).

Reliable object manipulation requires understanding physical properties that vary across objects and environments. Vision-language model (VLM) planners can reason about friction and stability in general terms; however, they often cannot predict how a specific ball will roll on a particular surface or which stone will provide a stable foundation without direct experience. We present PhysMem, a memory framework that enables VLM robot planners to learn physical principles from interaction at test time, without updating model parameters. The system records experiences, generates candidate hypotheses, and verifies them through targeted interaction before promoting validated knowledge to guide future decisions. A central design choice is verification before application: the system tests hypotheses against new observations rather than applying retrieved experience directly, reducing rigid reliance on prior experience when physical conditions change. We evaluate PhysMem on three real-world manipulation tasks and simulation benchmarks across four VLM backbones. On a controlled brick insertion task, principled abstraction achieves 76% success compared to 23% for direct experience retrieval, and real-world experiments show consistent improvement over 30-minute deployment sessions.