---
base_model: Qwen/Qwen3.5-4B
language:
- en
license: apache-2.0
tags:
- robotics
- vla
- vision-language-action
- robot-manipulation
- sft
- unsloth
- qwen3
- multimodal
pipeline_tag: image-text-to-text
---

# ReasonFlow VLA — Stage 1: Robot Grounding SFT

This is the Stage 1 checkpoint of **ReasonFlow VLA**, a multi-stage Vision-Language-Action system
developed as a Final Year Project at **Universiti Teknikal Malaysia Melaka (UTeM)**.

It is a **Qwen3.5-4B** (natively multimodal) model fine-tuned via supervised instruction tuning across
eight robot-domain datasets to establish foundational robotic knowledge before any RL or distillation
is applied in later stages.

> This checkpoint is the shared initialisation point for both the **Teacher** and **Student** models
> in [Stage 2 (GRPO Teacher-Student Distillation)](https://github.com/shreethar/Shree_FYP).

---

## Model Details

| Property | Value |
|----------|-------|
| **Base Model** | [Qwen/Qwen3.5-4B](https://huggingface.co/Qwen/Qwen3.5-4B) |
| **Modality** | Vision + Language (natively multimodal) |
| **Training Method** | Supervised Fine-Tuning (SFT) via [Unsloth](https://github.com/unslothai/unsloth) |
| **Training Samples** | ~560K |
| **Training Steps** | ~750K (~1 epoch) |
| **Learning Rate** | 1e-5 |
| **Batch Size** | 1 (gradient accumulation = 8, effective batch = 8) |
| **Image Resolution** | 448 × 448 |

---

## Training Data

The model was trained on eight curated datasets spanning trajectory prediction, affordance grounding,
task planning, video QA, and general visual captioning:

| Dataset | Task | Samples Used |
|---------|------|-------------:|
| [MolmoAct Trajectory](https://huggingface.co/datasets/allenai/MolmoAct-Pretraining-Mixture) | 2D end-effector trajectory prediction | ~200K (10%) |
| [RoboVQA](https://huggingface.co/datasets/google/robovqa) | Robot visual question answering | ~100K (10%) |
| [RoboFAC](https://huggingface.co/datasets/RoboFAC/RoboFAC) | Failure analysis & correction QA | ~64K (100%) |
| [ShareRobot Affordance](https://huggingface.co/datasets/ShareRobot/ShareRobot) | Affordance bounding box prediction | ~6.5K (100%) |
| [ShareRobot Planning](https://huggingface.co/datasets/ShareRobot/ShareRobot) | Multi-step task planning QA | ~100K (10%) |
| [Pixmo Cap](https://huggingface.co/datasets/allenai/pixmo-cap) | Dense image captioning | ~50K (10%) |
| [Pixmo Cap-QA](https://huggingface.co/datasets/allenai/pixmo-cap-qa) | Caption-grounded QA | ~50K (10%) |
| [Pixmo AMA](https://huggingface.co/datasets/allenai/pixmo-ask-model-anything) | Open-ended visual QA | ~50K (10%) |

> A compact pre-materialized subset (~51K samples) used for cloud training is available at
> [`shreethar/FYP-Stage2-dataset`](https://huggingface.co/datasets/shreethar/FYP-Stage2-dataset).

**Sampling policy:** datasets with more than 100K samples are sampled at ~10%; datasets smaller than
100K are kept in full.

---

## Task Format

All samples follow a two-turn chat format. Trajectory tasks output normalised waypoint lists;
QA tasks output free-form text.

**Trajectory example (MolmoAct):**
```
User:   [image] You are a robot manipulation assistant. Given an observation image and a
        task instruction, predict the end-effector's 2D trajectory as 5 waypoints.
        Output ONLY the coordinate list: [[x1,y1],[x2,y2],[x3,y3],[x4,y4],[x5,y5]]
        Task: Pick up the red cup.

Model:  [[142,308],[198,275],[241,233],[280,195],[310,162]]
```

**QA example (RoboFAC):**
```
User:   [video frames] You are a robot manipulation assistant. Answer questions about
        robot tasks, object affordances, and manipulation strategies.
        Why did the robot fail to grasp the object?

Model:  The gripper approached from the wrong angle — the contact point missed the
        graspable region of the handle. The robot should adjust its approach trajectory
        to align with the object's principal axis.
```

---

## Hardware

| Component | Spec |
|-----------|------|
| GPU | NVIDIA RTX A4000 (16 GB VRAM) |
| RAM | 128 GB @ 4400 MT/s |
| CPU | Intel Xeon w3-2425 |
| Training Time | ~10 days |

---

## Usage

```python
from transformers import AutoProcessor, AutoModelForImageTextToText

model = AutoModelForImageTextToText.from_pretrained(
    "shreethar/stage1_unsloth",
    torch_dtype="auto",
    device_map="auto",
)
processor = AutoProcessor.from_pretrained("shreethar/stage1_unsloth")
```

---

## Project Context

This checkpoint is **Stage 1** of the **ReasonFlow VLA** pipeline:

| Stage | Description | Status |
|:-----:|-------------|:------:|
| **1** | Robot Grounding SFT ← *this model* | ✅ Done |
| **2** | GRPO Teacher · Student Distillation | 🔄 In Progress |
| **3** | Action Expert — CFM Adapter | 📋 Planned |
| **4** | Partial VLM Coupling · Spatial Forcing | 📋 Planned |
| **5** | LIBERO Evaluation · RL Fine-Tuning | ⚗️ Optional |

Full project repository: [ReasonFlow VLA on GitHub](https://github.com/shreethar/Shree_FYP)

---

## Citation

If you use this checkpoint, please cite:

```bibtex
@misc{shreethar2025reasonflow,
  title   = {ReasonFlow VLA: A Multi-Stage Vision-Language-Action System with
             Latent Reasoning and Conditional Flow Matching},
  author  = {Shreethar},
  year    = {2025},
  note    = {Final Year Project, Universiti Teknikal Malaysia Melaka (UTeM)},
  url     = {https://huggingface.co/shreethar/stage1_unsloth}
}
```