Adaptive Trajectory Prediction via Transferable GNN
Yi XuLichen WangYizhou WangYun Fu
Proposes a transferable graph neural network framework that aligns feature distributions across disparate environments to prevent performance drops in cross-domain pedestrian trajectory forecasting.
Accurately predicting pedestrian movement is essential for safety, navigation, and automated planning in autonomous driving and robotics. Current prediction systems typically assume that pedestrian movement patterns observed during training will match those encountered during real-world deployment. In practice, however, pedestrian density, walking speeds, and acceleration vary dramatically across different physical environments, such as open streets versus crowded university plazas. This environmental mismatch creates a domain shift problem that severely degrades the accuracy of standard predictive models.
The article demonstrates this vulnerability across standard benchmarks and introduces a new predictive framework called the Transferable Graph Neural Network to overcome it. The primary objective is to evaluate whether integrating unsupervised domain adaptation directly into a network can bridge distribution gaps and generate reliable pedestrian trajectory predictions in new, unseen target environments.
To evaluate this framework, the authors designed a transfer-learning benchmark across five real-world pedestrian datasets: ETH, Hotel, University, Zara1, and Zara2. This benchmark generated 20 cross-scene prediction tasks where models trained on one source environment were required to adapt to a distinct target environment. The framework uses graph neural network layers to capture spatial relationships and pedestrian interactions, combines them with an attention mechanism to extract fine-grained, individual-level movement features, and aligns source and target feature distributions using a distance-minimizing alignment loss. Crucially, the model accesses only the past observed trajectory history of the new target scene without requiring future trajectory labels, reflecting realistic deployment constraints.
The experimental findings show substantial improvements over existing techniques. Across all 20 cross-domain tasks, the proposed framework achieved an average prediction error of 0.96 meters and a final endpoint error of 1.82 meters, consistently outperforming five leading baseline models. Compared to top-performing baselines like Social-STGCNN, SGCN, and PECNet, the framework reduced average trajectory error by approximately 21.3% and final displacement error by roughly 20.5%. Furthermore, ablation tests confirmed that incorporating an individual-level attention module and explicit domain alignment significantly outperforms simply pooling features or training models on mixed datasets without alignment.
These findings have direct operational and safety implications for autonomous vehicles and mobile robotics. High prediction error in unfamiliar surroundings increases collision risks, delays vehicle decision-making, and limits operational scalability. The results show that deploying models naively across disparate environments without domain alignment introduces severe bias, whereas an adaptive framework allows systems to transfer learned motion dynamics to new operating domains without costly, manual retraining or ground-truth data collection.
Organizations developing autonomous navigation systems should adopt domain-invariant learning frameworks to make predictive models resilient to environmental shifts. Development teams should prioritize fine-grained individual feature alignment over standard sample-level domain adaptation techniques. Before deploying these models into safety-critical operations, organizations should conduct pilot trials in edge-case environments characterized by extreme crowd densities or non-standard movement dynamics to validate operational safety thresholds.
While the evaluation provides high confidence across standard cross-scene benchmarks, the scope of the evaluation relies on five public surveillance-style datasets with specific observation-to-prediction ratios. Readers should account for uncertainties in unseen edge environments that may feature significantly more complex occlusions, high vehicle-pedestrian mixed traffic, or sensor noise not present in these standard datasets.
- Paper: Social LSTM: Human Trajectory Prediction in Crowded Spaces, Alexandre Alahi et al. (2016). Introduces the foundational Social LSTM pooling architecture on the ETH and UCY datasets that established multi-pedestrian interaction modeling for trajectory forecasting.
- Paper: Social GAN: Socially Acceptable Trajectories with Generative Adversarial Networks, Agrim Gupta et al. (2018). Pioneers generative multi-agent trajectory prediction with global pooling mechanisms, serving as a core baseline and architectural precursor for interaction-aware motion modeling.
- Paper: Trajectron++: Dynamically-Feasible Trajectory Forecasting with Heterogeneous Data, Tim Salzmann et al. (2020). Formulates multi-agent trajectory forecasting on spatiotemporal graphs across standard pedestrian benchmarks, establishing key graph-based motion modeling principles.
- Book: Domain-Adversarial Training of Neural Networks, Yaroslav Ganin et al. (2016). Establishes the fundamental domain-adversarial framework for learning domain-invariant feature representations under unsupervised domain shift.
- Paper: You'll never walk alone: Modeling social behavior for multi-target tracking, S. Pellegrini et al. (2009). Provides the original ETH pedestrian dataset and interaction models that form the standard cross-domain evaluation benchmark used in the source paper.
- Paper: Maximum Classifier Discrepancy for Unsupervised Domain Adaptation, Kuniaki Saito et al. (2017). Introduces decision boundary-based unsupervised domain adaptation, providing essential theoretical and methodological context for feature distribution alignment.
- Paper: Spatio-temporal Graph Convolutional Neural Network: A Deep Learning Framework for Traffic Forecasting, Bing Yu et al. (2017). Introduces spatiotemporal graph convolutional networks for forecasting structured relational dynamics, providing the architectural foundation for subsequent GNN predictors.
- Paper: Deep Domain Confusion: Maximizing for Domain Invariance, Eric Tzeng et al. (2014). Demonstrates how to optimize deep neural representations for domain invariance via explicit distribution alignment loss functions.
- Paper: EqMotion: Equivariant Multi-Agent Motion Prediction with Invariant Interaction Reasoning, Chenxin Xu et al. (2023). Extends multi-agent trajectory forecasting by embedding geometric equivariance and invariant interaction reasoning directly into the sequence-to-sequence motion network.
- Paper: Planning-oriented Autonomous Driving, Yi Hu et al. (2022). Integrates multi-agent motion forecasting into a comprehensive end-to-end framework that directly coordinates prediction with vehicle planning.
- Paper: Trajectory-guided Control Prediction for End-to-end Autonomous Driving: A Simple yet Strong Baseline, Penghao Wu et al. (2022). Applies predicted trajectories to guide closed-loop control and vehicle actuation for robust end-to-end autonomous driving.
- Paper: Generating Useful Accident-Prone Driving Scenarios via a Learned Traffic Prior, Davis Rempe et al. (2022). Leverages graph-based multi-agent motion priors to generate safety-critical adversarial scenarios for stress-testing autonomous vehicle planners.
