ArcMind

Dual-timescale hybrid SSM+Attention architecture for efficient robotics and IoT.

⚠️ Alpha release — architecture is functional and tested, pretrained weights coming soon. API may change.

What is ArcMind?

ArcMind is a neural architecture purpose-built for robotics and IoT edge deployment. It combines a fast State Space Model (SSM) path for continuous sensor stream processing with a slow exact attention path for episodic memory recall — all at 245K to 10.3M parameters.

The problem

Current approaches to "LMs for robotics" fall into two camps:

1. Massive VLA models (RT-2, OpenVLA, Pi-Zero) — 7B–55B parameters, cloud-dependent, text-centric tokenization. Can't run on edge hardware.
2. Shoehorned text SLMs (quantized Phi, TinyLlama on Jetson) — general-purpose text models forced onto constrained devices. Not designed for sensor streams.

Neither is purpose-built for the sensor-stream → reasoning → action loop that robotics and IoT actually need.

The approach

ArcMind introduces a dual-timescale hybrid that mirrors how robotic control actually works:

• Fast path (SSM): Processes every sensor frame at hardware rate (100–1000 Hz). O(n) time, O(1) decode memory, no KV cache. Produces smooth, physically plausible control signals.
• Slow path (Attention): Tiny exact attention (1–2 layers, 2–4 heads) runs at decision rate (1–10 Hz) over an episodic memory buffer for precise spatial/temporal recall.
• Sensor-native tokenization: Raw sensor frames projected directly into model dimension via learned linear layers. No vocabulary table — eliminates the ~40% parameter overhead of embedding tables in small text LMs.
• Episodic memory: Fixed-size ring buffer of compressed environment state snapshots. Enables landmark recall and obstacle memory without a growing KV cache.

Installation

Requirements: Python ≥ 3.10, PyTorch ≥ 2.1

pip install arcmind

For development:

git clone https://github.com/jemsbhai/arcmind.git
cd arcmind
pip install -e ".[dev]"
pytest tests/ -v  # 44 tests, all passing

Quick Start

import torch
from arcmind import ArcMindConfig, ArcMindModel

# Create a model from a preset
config = ArcMindConfig.robotics_small()
model = ArcMindModel(config)

# Simulate a sensor stream (batch=1, 100 timesteps, 12 channels)
sensor_data = torch.randn(1, 100, config.num_sensor_channels)

# Forward pass
model.reset_memory(batch_size=1)
actions = model(sensor_data)
print(actions.shape)  # (1, 100, 6)

# Inspect parameter breakdown
for component, count in model.count_parameters().items():
    print(f"  {component}: {count:,}")

Custom Configuration

# Build a custom config for your specific robot/sensor setup
config = ArcMindConfig(
    num_sensor_channels=9,    # e.g., 3-axis accel + 3-axis gyro + 3-axis mag
    d_model=96,
    num_ssm_layers=6,
    ssm_state_dim=12,
    num_attn_layers=1,
    num_attn_heads=3,
    num_memory_slots=32,
    action_dim=4,             # e.g., 4 motor commands
    sensor_freq_hz=200.0,
    decision_freq_hz=20.0,
)
model = ArcMindModel(config)

Model Presets

All parameter counts independently verified via test suite.

Preset	Params	SSM	Attention	Tokenizer	Target Hardware
iot_tiny	245K	73.5%	20.3%	0.2%	Cortex-M7, ESP32-S3
robotics_small	1.7M	84.7%	11.7%	0.1%	Jetson Orin Nano, RPi 5
robotics_medium	10.3M	82.4%	15.3%	0.1%	Desktop GPU, Jetson AGX

Key property: the sensor tokenizer is consistently <1% of total parameters, confirming the embedding-table-free design eliminates the parameter overhead that dominates sub-100M text LMs.

Architecture

Sensor Stream → SensorTokenizer → SSMCore (fast, 100-1000 Hz)
                                      ↓ periodic snapshot
                                 EpisodicMemory (ring buffer)
                                      ↓ read
SSM output → SlowAttention (slow, 1-10 Hz) ← memory slots
                   ↓ gated fusion
              ActionHead → action output

Design rationale:

• SSM:Attention parameter ratio of ~5:1 to ~8:1 extends the Granite 4 (9:1) and Jamba (7:1) ratios, justified by sensor streams being temporally smoother than text.
• Only 2–4 attention heads for recall, based on retrieval-aware distillation research showing 2–3 heads suffice for recall in SSM hybrids.
• Episodic ring buffer adapted from Expansion Span's reserved attention context for distant retrieval, applied here to compressed environment state snapshots.

Project Status

• Core architecture (SSM + Attention + Memory + Gating)
• Sensor-native tokenizer
• Three validated presets (IoT, Robotics-S, Robotics-M)
• Full test suite (44 tests)
• PyPI package
• Training pipeline
• Benchmark evaluation (MuJoCo, sensor datasets)
• Pretrained weights on HuggingFace
• Research paper

Citation

Paper forthcoming. For now:

@software{arcmind2026,
  title={ArcMind: Dual-Timescale Hybrid SSM+Attention for Efficient Robotics and IoT},
  author={Syed, Muntaser},
  year={2026},
  url={https://github.com/jemsbhai/arcmind},
}

License

MIT License. See LICENSE for details.