Towards Scalable Coverage-Based Testing of Autonomous Vehicles

To deploy autonomous vehicles(AVs) in the real world, developers must understand the conditions in which the system can operate safely. To do this in a scalable manner, AVs are often tested in simulation on parameterized scenarios. In this context, it’s important to build a testing framework that partitions the scenario parameter space into safe, unsafe, and unknown regions. Existing approaches rely on discretizing continuous parameter spaces into bins, which scales poorly to high-dimensional spaces and cannot describe regions with arbitrary shape. In this work, we introduce a problem formulation which avoids discretization – by modeling the probability of meeting safety requirements everywhere, the parameter space can be paritioned using a probability threshold. Based on our formulation, we propose GUARD as a testing framework which leverages Gaussian Processes to model probability and levelset algorithms to efficiently generate tests. Moreover, we introduce a set of novel evaluation metrics for coverage-based testing frameworks to capture the key objectives of testing. In our evaluation suite of diverse high-dimensional scenarios, GUARD significantly outperforms existing approaches. By proposing an efficient, accurate, and scalable testing framework, our work is a step towards safely deploying autonomous vehicles at scale.