ACERobotics/ACE-Brain-0.6-9B

ACE-Brain-0.6: Scaling Spatial Grounding for Physical Foundation Models

🌐 Project Page  |  🤗 Hugging Face  |  📔 Technical Report  |  🤖 GitHub

Overview

ACE-Brain-0.6-9B is a 9B vision-language model that strengthens spatial grounding for physical foundation models. Given one or more images and a natural-language query, it identifies task-relevant objects, counts instances, resolves spatial relationships, and localizes interaction targets.

Built on Qwen3.5-9B, ACE-Brain-0.6-9B is fine-tuned on approximately 1.5 million training samples. A unified data pipeline converts robot manipulation recordings, egocentric interactions, object and part annotations, and spatial data into verifiable grounding supervision. Training updates the language-model parameters while keeping the vision encoder frozen.

On seven public grounding benchmarks, ACE-Brain-0.6-9B achieves a reported Avg-7 of 75.41, compared with 73.68 for GPT-6 Astra. It exceeds Astra on four of seven benchmarks, with remaining gaps on PixMo-Count, RefSpatial, and PointArena.

Key Features

• Unified grounding interface: Supports points, point lists, bounding boxes, integer counts, and categorical answers (yes, no, or none) for target identification, multi-instance perception, spatial grounding, and interaction grounding.
• Robot-centered data pipeline: Automatically annotates manipulation recordings and combines them with complementary visual sources to broaden grounding coverage.
• Verifiable supervision: Checks object labels, requires complete instance sets for counting, verifies absent-target questions, and excludes evaluation images and episodes from training.
• Scaling with diverse data: Grounding performance improves across progressively larger and more diverse training releases under a fixed backbone and training recipe.
• Strong robot-scene performance: Achieves 93.42 on RobotGrounding, the team's held-out evaluation set covering referring, counting, absent targets, spatial judgments, and cross-view correspondence.

Performance Highlights

Results below are reported in Table 1 of the technical report. Higher is better; bold marks the best score among the models shown.

Benchmark	GPT-5.5	GPT-5.6-sol	GPT-6 Astra	Claude Opus 5.5	Gemini 4 Argon	ACE-Brain-0.6-9B
Where2Place	45.25	46.23	71.10	66.44	71.20	81.44
PixMo-Count	82.61	83.55	88.10	83.74	87.71	86.96
RoboSpatial	59.19	64.34	69.55	73.30	80.94	76.56
RefSpatial	60.29	54.51	80.14	71.10	51.56	71.84
PointArena	68.02	69.76	75.36	61.20	66.40	74.13
RoboAfford	68.04	71.45	84.94	75.10	71.48	88.14
ShareRobot (affordance)	38.57	36.66	46.60	40.20	29.53	48.82
Avg-7 · public benchmarks	60.28	60.93	73.68	67.30	65.55	75.41
RobotGrounding · in-house benchmark	83.96	85.18	91.10	90.89	78.51	93.42

Avg-7 is the unweighted mean of the seven public benchmark scores. RobotGrounding is evaluated separately and is not included in Avg-7. It contains 2,591 questions and reports a macro average over 14 scoring groups.

Inference Example

Install a Transformers version with Qwen3.5 support:

pip install -U "transformers>=5.2.0" accelerate torch torchvision pillow

The example uses the checkpoint and processor files from this repository in non-thinking mode. Replace scene.jpg and the query with your own image and grounding instruction.

import torch
from PIL import Image
from transformers import AutoProcessor, Qwen3_5ForConditionalGeneration

model_id = "ACERobotics/ACE-Brain-0.6-9B"

processor = AutoProcessor.from_pretrained(model_id)
model = Qwen3_5ForConditionalGeneration.from_pretrained(
    model_id,
    dtype="auto",
    device_map="auto",
).eval()

image = Image.open("scene.jpg").convert("RGB")
messages = [
    {
        "role": "user",
        "content": [
            {"type": "image", "image": image},
            {
                "type": "text",
                "text": (
                    "Point to the red cup in the image. "
                    "Return a point as [[x, y]], with integer coordinates "
                    "normalized to [0, 1000]. Return none if it is absent."
                ),
            },
        ],
    }
]

inputs = processor.apply_chat_template(
    messages,
    tokenize=True,
    add_generation_prompt=True,
    enable_thinking=False,
    return_dict=True,
    return_tensors="pt",
).to(model.device)

with torch.inference_mode():
    generated_ids = model.generate(
        **inputs,
        max_new_tokens=128,
        do_sample=False,
    )

answer_ids = generated_ids[:, inputs["input_ids"].shape[1]:]
answer = processor.batch_decode(
    answer_ids,
    skip_special_tokens=True,
    clean_up_tokenization_spaces=False,
)[0]
print(answer)

Grounding coordinates are integers normalized to [0, 1000] along each image axis. Depending on the query, the model can return a point, a list of points, a box, a count, or a categorical answer. Free-space grounding identifies unoccupied 2D regions and does not by itself establish 3D placement feasibility.

The example uses greedy decoding for simplicity. The reported benchmarks use temperature 0.2 and a 128-token output budget, except PixMo-Count, which uses 1,024 tokens. See the report for the full evaluation protocol and the Transformers Qwen3.5 documentation for the model interface.

Citation

If you find ACE-Brain-0.6-9B useful for your research and applications, please refer to our technical report:

ACE-Brain Team. ACE-Brain-0.6: Scaling Spatial Grounding for Physical Foundation Models.

Read the technical report (PDF). A formal BibTeX entry will be added when the arXiv identifier is available.