Pedestrian Trajectory Prediction via Hierarchical Dynamics Decomposition

Predicting human future trajectories is crucial for various intelligent systems and applications. Previous approaches typically adopt a direct prediction strategy, which decodes trajectory features directly into future coordinates. However, they overlook different hierarchical high-order velocities, which have stronger representational abilities in dynamics. In this paper, we introduce HDDNet, a novel trajectory prediction framework that follows dynamical principles and employs a hierarchical dynamics decomposition strategy. Specifically, HDDNet models future trajectories by progressively transferring trajectory coordinates into velocity, acceleration, and jerk, up to the highest-order velocity, which sequentially represent a broader receptive field and a more compact representation of motion dynamics. Furthermore, we design a hierarchical dynamics decomposition decoder with a corresponding dynamics loss, which predicts future trajectories by sequentially refining human motions from the highest-order velocity down to the final coordinates. Compared to the traditional direct prediction strategy, our approach makes better use of dynamic information at different levels. Extensive experiments and ablation studies on the ETH-UCY, SDD and GigaTraj datasets demonstrate that our method outperforms existing state-of-the-art approaches.