Enabling unit testing of already-integrated AI software systems: The case of Apollo for autonomous driving

The advanced AI-based software used for autonomous driving comprises multiple highly-coupled modules that are data and control dependent. Deploying those already-integrated software frameworks makes unit testing, a fundamental step in the validation process of critical software, very challenging in safety-critical systems. To tackle this issue, in this paper, we show the steps we followed to develop standalone versions of the modules in an industry-level autonomous driving framework (Apollo) by applying several modifications to its architectural design. We show how the standalone modules have the same functional behavior as their integrated counterpart modules. We exemplify the benefits of standalone modules by performing incremental analysis of the software timing requirements of each module running on a heterogeneous System on Chip (SoC). This is a mandatory step to consolidate and integrate software modules guaranteeing timing constraints (e.g. related to freedom from interference) while maximizing SoC utilization.This work has been partially supported by the Spanish Ministry of Science, Innovation and Universities under grant PID2019-110854RB-I00/AEI/10.13039/501100011033, the UP2DATE European Union’s Horizon 2020 (H2020) research and innovation programme under grant agreement No 871465, the SuPerCom European Research Council (ERC) project under the European Union’s Horizon 2020 research and innovation programme (grant agreement No. 772773), and the HiPEAC Network of Excellence.Peer ReviewedPostprint (author's final draft