swarm-laya

An unofficial, independent fine-tune of Laya by Nandhakishor M / Convai Innovations — not affiliated with or endorsed by the original project.

Simulation-only. Fine-tuned and evaluated entirely in a PyBullet swarm simulator — not tested on physical robots. See Aditharavind/swarm-laya for the full pipeline, and the v1 — no vision note there: this checkpoint decides from ground-truth structured state, not camera images.

A Laya checkpoint (ModernBERT-large encoder, 421M params) fine-tuned via RLCD to make one decision per robot per timestep in a synthetic swarm-robotics setting: given a robot's state (position, battery, distance/heading to target and base, nearest-obstacle clearance, nearest-teammate distance, radio and sensor-noise status), pick one of move_to_target, avoid_obstacle, return_to_base, request_swarm_help, hold_position.

Training

Base: convaiinnovations/laya
Data: Aditharavind/swarm-laya-decisions (5,368 training states from a PyBullet simulator + potential-field expert policy, soft-label RLCD targets)
Recipe: RLCD (GRPO-style policy gradient over proper scoring rules + soft cross-entropy), 4 epochs, single 6GB consumer GPU, 8-bit AdamW (bitsandbytes) — plain fp32 AdamW does not fit a 421M encoder in 6GB
Calibration: one temperature per question type, fit on the held-out val split after training

Evaluation

	in-distribution (test, n=611)	unseen swarms (ood, n=2,000)
decision accuracy	83.1%	90.2%
latency (p50 / p95)	31.4 / 32.1 ms	32.4 / 35.7 ms

Closed-loop rollouts (this model driving every robot vs. the hand-coded expert-policy oracle, 15 episodes each; episodes capped at 25 steps for eval speed, so completion rate is a model-vs-expert comparison under identical conditions, not an absolute success rate):

	collision rate (expert / model)	task completion (expert / model)
in-distribution	2.1% / 6.0%	20.3% / 17.4%
unseen swarms	3.9% / 6.9%	11.9% / 15.0%

"Unseen swarms" = 9-16 robots / 16-28 obstacles, never seen during training (train/val/test used 2-8 robots / 3-14 obstacles).

The weakest per-class accuracy is hold_position (~4-5%) — it's the rarest action in the training distribution before balancing; see the source repo's README for more on this and other known limits.

Use

import laya
agent = laya.Agent("Aditharavind/swarm-laya")

state = {
    "robot_id": 0, "position": [-3.4, -2.0], "battery_percent": 12.0,
    "distance_to_target": 8.5, "heading_to_target_deg": -32.0,
    "distance_to_base": 4.0, "sensor_noise_std_m": 0.0,
    "radio_link_degraded": False, "teammates_in_comm_range": 1, "swarm_size": 5,
    "nearest_obstacle": {"clearance_m": 2.0, "radius_m": 0.8},
    "nearest_teammate": {"distance_m": 3.9, "battery_percent": 40.0, "radio_link_degraded": False},
}
questions = {
    "next_action": {
        "type": "choice",
        "instructions": "Given this robot's state within the swarm, what should it do next?",
        "criteria": {
            "move_to_target": "No immediate hazard nearby and battery is sufficient; head toward the shared target.",
            "avoid_obstacle": "An obstacle or a teammate is close enough that the direct path is unsafe; steer around it.",
            "return_to_base": "Battery is low enough that continuing the mission risks stranding the robot; head back to base to recharge.",
            "request_swarm_help": "The robot is blocked, lost communication reliability, or its sensors are too noisy to act confidently, and a nearby teammate could assist or relay.",
            "hold_position": "Conditions are too uncertain or congested to move safely and no teammate is reachable to help; stay put and wait for the situation to clear.",
        },
    }
}
result = agent.predict(state, questions)
print(result["answers"]["next_action"]["choice"])

License

Apache 2.0, matching Laya's own license.