Control of Distributed Cyber-Physical Systems under Partial Information and Limited Communication

Abstract

The principal objective of this project is the development of novel control architectures and computationally efficient controller design algorithms for distributed cyber--physical systems with decentralized information infrastructures and limited communication capabilities. We are interested in distributed cyber-- physical systems where the system components are able to communicate with one another. Cooperative active safety in Intelligent Transportation Systems is our focus cyber--physical application. Our methodology for design of communicating distributed hybrid controllers aims to integrate in a novel manner discrete--event controller design and hybrid controller design and optimization. Both safety and liveness specifications are being addressed. The methodology to be developed exploits problem decomposition and is aimed at cyber--physical systems that share features of modularity in system representation, partial information, model uncertainty, and limited communication. The technical approach consists of the following steps: (i) abstraction of the essential features of the cyber--physical system as a formal discrete--event model; (ii) synthesis of a set of distributed discrete--event control laws as well as sensor activation and communication strategies for the system agents; (iii) incorporation of the underlying continuous dynamics of the cyber--physical system with the preceding distributed control logic for the purpose of hybrid controller design and quantitative performance optimization; (iv) iteration between steps (ii) and (iii) for performance improvement.

We capture the effects of model uncertainties and partial information at the discrete level by introducing uncontrollable events in the model abstraction. The synthesis at step (ii) is then carried out so that safety and liveness are insured despite the presence of the uncontrollable events. Step (iii) is accomplished by exploiting the property of differential flatness, which is common to a large class of cyber--physical system. By this property, we can translate a sequence of events that is accepted at the discrete level into an input for the cyber--physical system by simple algebraic mapping.

The cyber--physical application that will serve as a platform for the validation of the results is that of cooperative active safety in Intelligent Transportation Systems. The essential features of collision avoidance scenarios (safety and liveness) will be retained from a roundabout test--bed, which are being implemented in PI Del Vecchio's laboratory.

Award ID: 0930081