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International audience; The increased complexity of programs and pro-cessors is an important challenge that the embedded real-time systems community faces today, as it implies substancial timing variability. Processor features like pipelines or communication buses are not always completely described, while black-box programs integrated by third parties are hidden for IP reasons. This situation explains the use of statistical approaches to study the timing variability of programs. Most existing work is concentrated on the guarantees provided by positive answers to statistical tests, while our current work concerns potential algorithms based on the negative answers to these tests and their impact on the timing analysis. We introduce here one such algorithm, the Walking Kolmogorov-Smirnov test (WKS).

International audience; Existing task models for cyber-physical systems have been proposed to merge the requirements associated to the stability of control tasks managing physical components, and to the schedulability of these tasks. Nevertheless, these models stay to a high level without covering concerns like the data and/or precedence constraints between different control tasks as well as non-control tasks, the impact of period variation between dependent control tasks and the impact of data constraints on the execution times of control tasks. Our current work concentrates on discussing properties of a new task model in order to cover these concerns.

International audience; The real-time systems community is facing the lack of benchmarks adapted to measurement-based worst-case execution time (WCET) estimators. We provide in this paper first steps towards such benchmarks by proposing them for single core microcontrollers, while we leave as future work the migration to multicore microcontrollers. The considered benchmarks are the programs of an open source drone autopilot. We conclude the paper by underlining the main difficulties of such migration.

International audience; In this paper, we present our ongoing work on verification activities of the software used in a safety-critical embedded system dedicated to autonomous vehicles. These activities are focused on the use of formal methods for the verification of functional properties on the embedded code, and statistical methods for the analysis of its Worst-Case Execution Time (WCET). The project's goal is to address some technical barriers of software verification that will impact the safety demonstration of future autonomous driving systems. These barriers are challenging because of the high complexity of an embedded hardware and software, and appeal for methods and tools reaching the highest level of rigorousness.

International audience; The design of cyber–physical systems (CPSs) is facing the explosion of new functionalities requiring increased computation capacities and, thus, the introduction of multi-core processors. Moreover, some functionalities may impose precedence constraints between the programs implementing these new functionalities. While important effort has been dedicated to the scheduling of precedence constraints tasks on multi-core processors, existing work considers either partitioned scheduling for a single precedence graph defining precedence constraints between sub-tasks, or global scheduling policies. In this paper, we consider partitioned scheduling for multiple precedence graphs defining precedence constraints between tasks. We propose a partitioning heuristic that minimizes communication delays while maximizing sub-tasks parallelism. We also propose to decrease the complexity of existing schedulability analysis by providing appropriate graph reductions.

International audience

International audience