Augmenting Safety-Critical Driving Scenarios while Preserving Similarity to Expert Trajectories
This work addresses safety-critical driving scenarios for autonomous vehicles, but it is incremental as it builds on existing trajectory augmentation methods.
The paper tackles the problem of distributional shift in imitation learning for safety-critical driving scenarios by proposing a trajectory augmentation method that maintains similarity to expert data, resulting in significantly improved closed-loop performance.
Trajectory augmentation serves as a means to mitigate distributional shift in imitation learning. However, imitating trajectories that inadequately represent the original expert data can result in undesirable behaviors, particularly in safety-critical scenarios. We propose a trajectory augmentation method designed to maintain similarity with expert trajectory data. To accomplish this, we first cluster trajectories to identify minority yet safety-critical groups. Then, we combine the trajectories within the same cluster through geometrical transformation to create new trajectories. These trajectories are then added to the training dataset, provided that they meet our specified safety-related criteria. Our experiments exhibit that training an imitation learning model using these augmented trajectories can significantly improve closed-loop performance.