Autonomous Driving Systems (ADSs) are safety-critical, and must be fully tested before being deployed on real-world roads. To comprehensively evaluate the performance of ADSs, it is essential to generate various safety-critical scenarios. Most of existing studies assess ADSs either by searching high-dimensional input space, or using simple and pre-defined test scenarios, which are not efficient or not adequate. To better test ADSs, this paper proposes to automatically generate safety-critical test scenarios for ADSs by influential behavior patterns, which are mined from real traffic trajectories. Based on influential behavior patterns, a novel scenario generation technique, CRISCO, is presented to generate safety-critical scenarios for ADSs testing. CRISCO assigns participants to perform influential behaviors to challenge the ADS. It generates different test scenarios by solving trajectory constraints, and improves the challenge of those non-critical scenarios by adding participants’ behavior from influential behavior patterns incrementally. We demonstrate CRISCO on an industrial-grade ADS platform, Baidu Apollo. The experiment results show that our approach can effectively and efficiently generate critical scenarios to crash ADS, and it exposes 13 distinct types of safety violations in 12 hours. It also outperforms two state-of-art ADS testing techniques by exposing more 5 distinct types of safety violations on the same roads.

Autonomous Driving Systems (ADSs) are safety-critical systems, and safety violations of Autonomous Vehicles (AVs) in real traffic will cause huge losses. Therefore, ADSs must be fully tested before deployed on real world roads. Simulation testing is essential to find safety violations of ADS. This paper proposes MOSAT, a multi-objective search-based testing framework, which constructs diverse and adversarial driving environment to expose safety violations of ADSs. Specifically, based on atomic driving maneuvers, MOSAT introduces motif pattern, which describes a sequence of maneuvers that can challenge ADS effectively. MOSAT constructs test scenarios by atomic maneuvers and motif patterns, and uses multi-objective genetic algorithm to search for adversarial and diverse test scenarios. Moreover, in order to test the performance of ADS comprehensively during long-mile driving, we design a novel continuous simulation testing technique, which runs the scenarios generated by multiple parallel search processes alternately in the simulator and can continuously create different perturbations to ADS. We demonstrate MOSAT on an industrial-grade platform, Baidu Apollo, and the experimental results show that MOSAT can effectively generate safety-critical scenarios to crash ADSs and it exposes 11 distinct types of safety violations in a short period of time. It also outperforms state-of-the-art techniques by finding more 6 distinct safety violations on the same road.