Organizations: SIGS, Tsinghua University, China · Shanghai Jiao Tong University, China · Wuhan University of Technology, China · City University of Hong Kong, Hong Kong (China SAR) · AiDlab, Hong Kong (China SAR)
Vision-language-action (VLA) models often expose spatial grounding through autoregressive text coordinates or opaque action tokens, creating brittle interfaces between multimodal reasoning and robot execution. We present Pointing-VLA, a typed hidden-state spatial readout built on Embodied-R1. Geometry-specific heads predict normalized points, object-functional grounding (OFG) heatmaps, and visual trajectories without serializing geometry as text. For the evaluated Bridge/WidowX and physical pick-place deployments, an explicit execution contract assigns PICK to source-conditioned OFG and PLACE to Pointing, providing direct stage-aligned spatial targets. Pointing-VLA achieves SOTA performance on Bridge/WidowX, averaging 72.9% across the evaluated four-task set without Bridge-specific finetuning under collision-enabled CuRobo execution. Pointing and OFG show complementary strengths across native and cross-dataset evaluations. The OFG/contact readout transfers to NORA-1.5, preserving or improving success while reducing recorded controller time by more than 20×; typed heads are also 6.68--6.90× faster than Embodied-R1 text decoding on a shared external suite. When integrated as spatial guidance for a π0.5 action policy, Pointing-VLA raises autonomous real-robot success from 52.7% to 80.7% across three visual contexts. These results establish typed spatial readouts as an efficient, inspectable interface between embodied reasoning and robot execution.
Figures & tables
Figure 1: Representative text-coordinate failures. Left: generation yields no parseable coordinate. Right: [222, 172] is parseable but lies outside the target region.
Figure 2: Pointing-VLA architecture and typed interfaces. Embodied-R1 hidden states feed point, OFG/contact-heatmap, and VTG-waypoint heads; fixed PICK/PLACE slots use source-conditioned OFG/Pointing, and a wrapper maps image geometry to robot coordinates.
Figure 3: Stage-wise training. Geometry warm-up trains the adapter, eight queries, and geometry head; LoRA specialization updates only low-rank backbone parameters; task continuation updates only the required subset. Snowflakes and flames mark frozen and trainable modules.
Model
VABench-P acc. ↑
Part-Afford.2K acc. ↑
GPT-4o
9.3
10.2
ASMv2
10.1
13.8
RoboBrain
7.0
25.3
Qwen2.5-VL
9.9
23.4
RoboPoint ( 16 )
19.1
27.6
FSD ( 17 )
61.8
9.6
Table 1: Native point-in-region grounding accuracy (%). Pointing-VLA uses its Pointing head for VABench-P and its OFG head for the full Part-Affordance-2K run.
Figure 4: Representative successful real-robot rollouts across three visual contexts, each ordered from initialization to stable release.
Vision-Language-Action (VLA) models typically map visual observations and linguistic instructions directly to control signals. This "black-box" mapping forces a single forward pass to simultaneously handle instruction interpretation, spatial grounding, and low-level control, often leading to poor spatial precision and limited robustness in out-of-distribution scenarios. To address these limitations, we propose VP-VLA, a dual-system framework that decouples high-level reasoning and low-level execution via a structured visual prompting interface. Specifically, a "System 2 Planner" decomposes complex instructions into sub-tasks and identifies relevant target objects and goal locations. These spatial anchors are rendered directly within the native RGB observation space as modality-consistent visual prompts, such as crosshairs and bounding boxes. This avoids the modality mismatch introduced by dense masks, affordance maps, or additional control-specific representations. Guided by these prompts and enhanced by a novel auxiliary visual grounding objective during training, a "System 1 Controller" reliably generates precise low-level execution motions. Extensive experiments in simulation and real world demonstrate that VP-VLA surpasses state-of-the-art end-to-end baselines including QwenOFT and GR00T-N1.6. Project page: https://visualprompt-vla.github.io/
In this paper, we propose GTA-VLA(Guide, Think, Act), an interactive Vision-Language-Action (VLA) framework that enables spatially steerable embodied reasoning by allowing users to guide robot policies with explicit visual cues. Existing VLA models learn a direct "Sense-to-Act" mapping from multimodal observations to robot actions. While effective within the training distribution, such tightly coupled policies are brittle under out-of-domain (OOD) shifts and difficult to correct when failures occur. Although recent embodied Chain-of-Thought (CoT) approaches expose intermediate reasoning, they still lack a mechanism for incorporating human spatial guidance, limiting their ability to resolve visual ambiguities or recover from mistakes. To address this gap, our framework allows users to optionally guide the policy with spatial priors, such as affordance points, boxes, and traces, which the subsequent reasoning process can directly condition on. Based on these inputs, the model generates a unified spatial-visual Chain-of-Thought that integrates external guidance with internal task planning, aligning human visual intent with autonomous decision-making. For practical deployment, we further couple the reasoning module with a lightweight reactive action head for efficient action execution. Extensive experiments demonstrate the effectiveness of our approach. On the in-domain SimplerEnv WidowX benchmark, our framework achieves a state-of-the-art 81.2% success rate. Under OOD visual shifts and spatial ambiguities, a single visual interaction substantially improves task success over existing methods, highlighting the value of interactive reasoning for failure recovery in embodied control. More details of the project can be found here: https://github.com/FutianLabs/GTA-VLA.
Yiran Ling, Qing Lian, Jinghang Li +6
Faculty of Computing, Harbin Institute of Technology · International Digital Economy Academy (IDEA) · National Key Laboratory of Smart Farm Technologies and Systems +4
Vision-Language-Action (VLA) models leverage large-scale vision-language pretraining for flexible robot manipulation, yet at test time they remain brittle to changed object positions and to familiar scenes paired with different instructions. A growing family of methods addresses this brittleness by supplying the policy with grounding signals, such as 2D pixel coordinates for object localization and placement. However, we find that how the grounding signal is represented and injected matters more than the signal itself. In this work, we propose a lightweight module that represents the grounding signal in 3D and injects the resulting embedding directly into the action head. The module is a two-layer MLP and requires no changes to the VLA backbone or pretraining pipeline, yet it yields substantially larger gains than language- or visual-prompting alternatives. On LIBERO-PRO, our method improves the average success rate of GR00T-N1.6 from 31.2 to 77.5 under task perturbation and from 28.1 to 60.2 under position perturbation. Comparable gains are also achieved for π0.5, demonstrating that the mechanism is backbone-agnostic across VLAs with diffusion-based action heads. We further validate the practical applicability with real-world experiments. Together, these results support our central finding: lifting adequate 2D grounding into 3D and injecting it into the action head enables spatial and instance-level task generalization in VLAs.
Shiang-Feng Tsai, Jin-Cheng Jhang, Yen-Ling Tai +5
National Tsing Hua University · National Yang Ming Chiao Tung University