A generic concept to increase the robustness of embedded systems by trust management

Embedded systems permeate increasingly complex, unstructured and non-stationary environments like e.g. car driver assistance systems and mobile robots. The demands on their dependability hence rise, especially in case of human interaction. But as the complexity increases, several sources of uncertainty are likely to increase as well up to an unacceptable level. Reasons are for instance noise, vagueness and ambiguity of information about the environment and also disturbances and anomalies in the interaction with it. Because many operations are safety-critical, this paper presents trust management as a generic approach for addressing these uncertainties. It builds on modeling the uncertainty of the information about the state of the system and about the interaction with its environment explicitly by so-called trust signals. These are propagated and processed throughout the whole embedded system in order to change from a high performance behavior in case of certain, hence trustworthy information to a robust behavior with less performance in case of uncertain information. The trust management approach works without a formal model of the application and is hence easy to use. Its application is outlined by a simple sensor fusion example.