Technical Report: Artificial DNA - a Concept for Self-Building Embedded Systems

Embedded systems are growing more and more complex because of the increasing chip integration density, larger number of chips in distributed applications and demanding application fields (e.g. in cars and in households). In the near future it will become reality to have thousands of computing nodes within an embedded system. Bio-inspired techniques like self-organization are a key feature to handle this complexity. We have developed the Artificial Hormone System (AHS) as a decentralized, self-organizing, self-healing and self-optimizing mechanism to assign tasks to computing nodes of an embedded real-time system. The AHS is able to handle task assignment in complex embedded systems with a large number of processor cores. However, to do so the AHS needs a blueprint of the structure and organization of the embedded application. This covers the segmentation of the application into tasks, the cooperation and communication between these tasks, the suitability of the processor cores for each of these tasks, etc. Currently, these assignments are done manually by the system developer, but in the future this is no longer feasable for large embedded systems having a large number of cores and tasks. The idea is to follow again a bio-inspired principle. In biology the structure and organization of a system is coded in its DNA. This can be adopted to embedded systems. The blueprint of the structure and organization of the embedded system will be represented by an artificial DNA. The artificial DNA has to be be held compact and stored in every processor core of the system (like the biological DNA is stored in every cell of an organism). This makes the system self-describing. Now, a mechanism like the AHS can transcribe the artificial DNA to setup and operate the embedded system accordingly at run-time. All the needed information for such a process like task structure, cooperation, communication and core suitability can be derived from the artificial DNA. Therefore, the system becomes self-building at run-time based on its DNA. This enables a maximum amount of robustness, adaptivity and flexibility. This technical report describes in detail the basic principles of the artificial DNA (Section 2) and its relationship to standard design methods for embedded systems (Section 3). A prototypic implementation is presented (Section 4) and evaluated (Section 5). Additionally, future work is detailly described (Section 6) and a conclusion is given (Section 7). The technical report extends and complements the publications [16] and [17].