SmartRefine: A Scenario-Adaptive Refinement Framework for Efficient Motion Prediction
Authors: Yang Zhou, Hao Shao, Letian Wang, Steven L. Waslander, Hongsheng Li, Yu Liu

Predicting the future motion of surrounding agents is essential for autonomous vehicles (AVs) to operate safely in dynamic human-robot-mixed environments. Context information such as road maps and surrounding agents' states provides crucial geometric and semantic information for motion behavior prediction. To this end recent works explore two-stage prediction frameworks where coarse trajectories are first proposed and then used to select critical context information for trajectory refinement. However they either incur a large amount of computation or bring limited improvement if not both. In this paper we introduce a novel scenario-adaptive refinement strategy named SmartRefine to refine prediction with minimal additional computation. Specifically SmartRefine can comprehensively adapt refinement configurations based on each scenario's properties and smartly chooses the number of refinement iterations by introducing a quality score to measure the prediction quality and remaining refinement potential of each scenario. SmartRefine is designed as a generic and flexible approach that can be seamlessly integrated into most state-of-the-art motion prediction models. Experiments on Argoverse (1 & 2) show that our method consistently improves the prediction accuracy of multiple state-of-the-art prediction models. Specifically by adding SmartRefine to QCNet we outperform all published ensemble-free works on the Argoverse 2 leaderboard (single agent track) at submission. Comprehensive studies are also conducted to ablate design choices and explore the mechanism behind multi-iteration refinement. Codes are available at https://github.com/opendilab/SmartRefine/.