Reactive-Replay Approach for Verification and Validation of Closed-Loop Control Systems in Early Development

Enhanced technological capabilities render the application of various, increasingly complex, functional concepts for automated driving possible. In the process, the significance of automotive software for a satisfactory driving experience is growing. To benefit from these new opportunities, thorough assessment in early development stages is highly important. It enables manufacturers to focus resources on the most promising concepts. For early assessment, a common approach is to set up vehicles with additional prototyping hardware and perform real world testing. While this approach is essential to assess the look-and-feel of newly developed concepts, its drawbacks are reduced reproducibility and high expenses to achieve a sufficient and balanced sample. To overcome these drawbacks, new flexible, realistic and preferably automated virtual test methods to complement real world verification and validation are especially required during early development phases. In this contribution, we present a method for automated system assessments based on the reuse of recorded driving data in closed-loop simulation and its application in early development of a predictive cruise control system. Firstly, we identify the requirements for early assessment of closed-loop system concepts, analyze the eligibility of established methods regarding the identified requirements and describe open challenges for development of automotive software systems with focus on early development stages. Our previously introduced Reactive-Replay approach addresses these challenges by enabling reuse of recorded driving data in closed-loop simulation. We complement this approach by introducing automated assessments for evaluation of software increments. By integrating periodic assessments into the development process, we achieve continuous tracking of software quality with very small effort. It is shown that the provision of a broad data pool for simulation based evaluation of new and refined concepts contributes to a substantial reduction of real world test mileage in early development stages.