Real-Time Execution of Action Chunking Flow Policies

Sergey Levine (UC Berkeley) · Kevin Black (University of California, Berkeley) · Manuel Galliker (Physical Intelligence)
action chunkingaction chunking policiesasynchronous executionbimanual manipulation tasksdiffusion-based modelsextreme latencyflow-based modelshigh-frequency control tasksinference delayinference-time algorithmkinetix simulatorreal-time performancetask throughputtemporal consistencyvision-language-action models

Modern AI systems, especially those interacting with the physical world, increasingly require real-time performance. However, the high latency of state-of-the-art generalist models, including recent vision-language-action models (VLAs), poses a significant challenge. While action chunking has enabled temporal consistency in high-frequency control tasks, it does not fully address the latency problem, leading to pauses or out-of-distribution jerky movements at chunk boundaries. This paper presents a novel inference-time algorithm that enables smooth asynchronous execution of action chunking policies. Our method, real-time chunking (RTC), is applicable to any diffusion- or flow-based VLA out of the box with no retraining. It generates the next action chunk while executing the current one, "freezing" actions guaranteed to execute and "inpainting" the rest. To test RTC, we introduce a new benchmark of 12 highly dynamic tasks in the Kinetix simulator, as well as evaluate 6 challenging real-world bimanual manipulation tasks. Results demonstrate that RTC is fast, performant, and uniquely robust to inference delay, significantly improving task throughput and enabling success in precise tasks