Sci-VLA: Agentic VLA Inference Plugin for Long-Horizon Tasks in Scientific Experiments
Yiwen Pang, Bo Zhou, Changjin Li, Xuanhao Wang, Shengxiang Xu, Deng-Bao Wang, Min-Ling Zhang, Shimin Di
TL;DR
This work tackles the state-gap problem in vision-language-action (VLA) models when executing long-horizon, composite scientific tasks. It introduces Sci-VLA, an LLM-based inference plugin that generates transitional action code to bridge transitions between atomic tasks, enabling reliable long-horizon workflows without retraining. The approach is validated in a digital twin (Autobio MuJoCo) with UR5e, showing a notable 42% average improvement in atomic-task success and enhanced execution coherence, with demonstrated transfer to real laboratories. By integrating transition inference and code insertion, Sci-VLA offers data-efficient, computation-efficient open-ended robotic laboratory capabilities. The work highlights the potential and challenges of sim-to-real transfer and calls for improved action precision and dataset balance to fully realize long-horizon robotic experimentation.
Abstract
Robotic laboratories play a critical role in autonomous scientific discovery by enabling scalable, continuous experimental execution. Recent vision-language-action (VLA) models offer a promising foundation for robotic laboratories. However, scientific experiments typically involve long-horizon tasks composed of multiple atomic tasks, posing a fundamental challenge to existing VLA models. While VLA models fine-tuned for scientific tasks can reliably execute atomic experimental actions seen during training, they often fail to perform composite tasks formed by reordering and composing these known atomic actions. This limitation arises from a distributional mismatch between training-time atomic tasks and inference-time composite tasks, which prevents VLA models from executing necessary transitional operations between atomic tasks. To address this challenge, we propose an Agentic VLA Inference Plugin for Long-Horizon Tasks in Scientific Experiments. It introduces an LLM-based agentic inference mechanism that intervenes when executing sequential manipulation tasks. By performing explicit transition inference and generating transitional robotic action code, the proposed plugin guides VLA models through missing transitional steps, enabling reliable execution of composite scientific workflows without any additional training. This inference-only intervention makes our method computationally efficient, data-efficient, and well-suited for open-ended and long-horizon robotic laboratory tasks. We build 3D assets of scientific instruments and common scientific operating scenes within an existing simulation environment. In these scenes, we have verified that our method increases the average success rate per atomic task by 42\% during inference. Furthermore, we show that our method can be easily transferred from the simulation to real scientific laboratories.
