Biblio

This paper studies a distributed event-triggered communication and control strategy that solves the multi-agent average consensus problem. The proposed strategy does not rely on the continuous or periodic availability of information to an agent about the state of its neighbors, but instead prescribes isolated event times where both communication and controller updates occur. In addition, all parameters required for its implementation can be locally determined by the agents. We show that the resulting network executions are guaranteed to converge to the average of the initial agents' states, establish that events cannot be triggered an infinite number of times in any finite time period (i.e., absence of Zeno behavior), and characterize the exponential rate of convergence. We also provide sufficient conditions for convergence in scenarios with time-varying communication topologies. Simulations illustrate our results.

When building large concurrent systems, one of the key difficulties lies in coordinating component behavior and, in particular, managing the access to shared resources of the execution platform. Components may interact through buses, message buffers, etc. leading to resource contention and potential deadlocks compromising safety-critical operations. The concurrent nature of such interactions is the root cause of the complexity of the resulting software. Thus, the complexity of software systems is exponential in the number of their components, making a-posteriori verification of their correctness practically infeasible. An alternative approach, taken by the BIP framework, consists in ensuring correctness-by-construction by applying automatic transformations to obtain executable code from formally defined models. Following this latter approach, we have designed and implemented a BIP design studio. We have studied extensions of the BIP language for specifying parameterized models and integrated them in the design studio to enhance scalability, reusability, and reduce model size. Additionally, we have studied and implemented a set of necessary and sufficient conditions for validating the consistency and encodability of BIP models at design time. We have developed code generation plugins from graphical BIP models to equivalent Java and BIP code. The generated BIP code can be verified for deadlock-freedom or safety properties using compositional verifications tools offered by the BIP framework.