Priority-Preserving Optimization of Status Quo ID-Assignments in Controller Area Network

摘要

Controller Area Network (CAN) is the prevailing solution for connecting multiple electronic control units (ECUs) in automotive systems. Every broadcast message on the bus is received by each bus participant and introduces computational overhead to the typically resource-constrained ECUs due to interrupt handling. To reduce this overhead, hardware message filters can be applied. However, since such filters are configured according to the message identifiers (IDs) specified in the system, the filter quality is limited by the nature of the ID-assignment. Although hardware message filters are highly relevant for industrial applications, so far, only the optimization of the filter design, but not the related optimization of ID-assignments has been addressed in the literature.In this work, we explicitly focus on the optimization of message ID-assignments against the background of hardware message filtering. More precisely, we propose an optimization algorithm transforming a given ID-assignment in such a way that, based on the resulting IDs, the quality of hardware message filters is improved significantly, i.e., the computational overhead introduced to each ECU is minimized, and, moreover, the priority order of the system remains unchanged. Conducting comprehensive experiments on automotive benchmarks, we show that our proposed algorithm clearly outperforms optimizations based on the conventional method simulated annealing with respect to the achieved filter quality as well as to the runtime.