ABPolicy: Asynchronous B‑Spline Flow Policy for Real‑Time and Smooth Robotic Manipulation
Fan Yang, Peiguang Jing, Kaihua Qu, Ningyuan Zhao, Yuting Su
AI summary
Problem
Synchronous inference in raw action spaces causes intra-chunk jitter, inter-chunk discontinuities, and execution stalls, which degrade smoothness and responsiveness to dynamic environments.
Approach
The method predicts continuous B-spline control points using a flow-matching model and enforces trajectory continuity through bidirectional prediction and local refitting optimization, all while running inference asynchronously to hide latency.
Key results
- Inherent intra-chunk smoothness via continuous B-spline control points
- Seamless inter-chunk continuity through bidirectional prediction and refitting
- Real-time responsiveness via asynchronous inference that eliminates execution stalls
- Higher success rates and reduced trajectory jerk across seven static and dynamic manipulation tasks
Why it matters
Provides a practical, latency-free control framework for robots operating in dynamic, real-world environments where smoothness and reactivity are critical.
Abstract
Robotic manipulation requires policies that are smooth and responsive to evolving observations. However, syn- chronous inference in the raw action space introduces several challenges, including intra-chunk jitter, inter-chunk disconti- nuities, and stop-and-go execution. These issues undermine a policy’s smoothness and its responsiveness to environmental changes. We propose ABPolicy, an asynchronous flow-matching policy that operates in a B-spline control-point action space. First, the B-spline representation ensures intra-chunk smooth- ness. Second, we introduce bidirectional action prediction cou- pled with refitting optimization to enforce inter-chunk conti- nuity. Finally, by leveraging asynchronous inference, ABPolicy delivers real-time, continuous updates. We evaluate ABPolicy across seven tasks encompassing both static settings and dy- namic settings with moving objects. Empirical results indicate that ABPolicy reduces trajectory jerk, leading to smoother motion and improved performance. Project website: https: //teee000.github.io/ABPolicy/.