Adv-BMT: Bidirectional Motion Transformer for Safety-Critical Traffic Scenario Generation

Yuxin Liu* 1 , Zhenghao Peng* 1 , Xuanhao Cui 1 , Bolei Zhou 1
1 University of California, Los Angeles

TL; DR

:fire: Adv-BMT augments diverse and realistic collision interactions from a input real-world driving log.

:star2: Adv-BMT generates collision interactions through adversarial initializations + reverse motion predictions.

:blue_car: Adv-BMT can be leveraged as a closed-loop generator for reinforcement adversarial learnings.

Adv-BMT

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Adv-BMT is a two-staged pipeline: first, it initializes diverse collision states between a new adversary agent and ego vehicle; then, it reconstructs the adversarial trajectories via BMT’s reverse predictions. A rule-based rejection sampling mechanism is used to filter candidate trajectories from unsatisfactory adversarial initializations, and maintain realistic collision interactions. In the output, the new agent maintains realistic interactions with surrounding traffic.

BMT Architecture

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BMT is a transformer-based motion prediction model, and is able to predict both future and history trajectories for vehicles, bicycles, and pedestrain agents.

Diverse Adversarial Behaviors

Safer Agent via Adversarial Learnings

Adversarial RL Evaluations

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Prior Works

CAT (CoRL 2022): Closed-loop adversarial training for safe end-to-end driving.

MetaDrive (TPAMI 2021): An open-source platform for large-scale traffic scenario simulation and modeling