VCAT: Vulnerability-aware and Curiosity-driven Adversarial Training for Enhancing Autonomous Vehicle Robustness
Xuan Cai, Zhiyong Cui, Xuesong Bai, Ruimin Ke, Zhenshu Ma, Haiyang Yu, Yilong Ren
TL;DR
Autonomous vehicles confront safety-critical risks in complex traffic, and existing adversarial training often fails to exploit the victim's intrinsic vulnerabilities or to explore the attacker’s policy space adequately. The authors propose VCAT, a vulnerability-aware and curiosity-driven adversarial training framework that combines a Victim Value Approximation Network to reveal vulnerabilities with Random Network Distillation to drive intrinsic exploration, all trained within a PPO-based attacker. The method alternates between an adversarial attack phase and an adversarial defense phase, enabling the victim to robustly counter pretrained attackers. In highway-env simulations, VCAT improves robust control and reduces crashes more effectively than conventional adversarial training and other RL baselines, particularly in rare edge-case scenarios. These findings offer a scalable approach to hardening AVs against sophisticated, sparsely rewarded adversaries, with available code to enable replication and extension.
Abstract
Autonomous vehicles (AVs) face significant threats to their safe operation in complex traffic environments. Adversarial training has emerged as an effective method of enabling AVs to preemptively fortify their robustness against malicious attacks. Train an attacker using an adversarial policy, allowing the AV to learn robust driving through interaction with this attacker. However, adversarial policies in existing methodologies often get stuck in a loop of overexploiting established vulnerabilities, resulting in poor improvement for AVs. To overcome the limitations, we introduce a pioneering framework termed Vulnerability-aware and Curiosity-driven Adversarial Training (VCAT). Specifically, during the traffic vehicle attacker training phase, a surrogate network is employed to fit the value function of the AV victim, providing dense information about the victim's inherent vulnerabilities. Subsequently, random network distillation is used to characterize the novelty of the environment, constructing an intrinsic reward to guide the attacker in exploring unexplored territories. In the victim defense training phase, the AV is trained in critical scenarios in which the pretrained attacker is positioned around the victim to generate attack behaviors. Experimental results revealed that the training methodology provided by VCAT significantly improved the robust control capabilities of learning-based AVs, outperforming both conventional training modalities and alternative reinforcement learning counterparts, with a marked reduction in crash rates. The code is available at https://github.com/caixxuan/VCAT.
