SGER: Algebraic Languages for Reconfigurable Hybrid Systems

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

Rounds CCR-0233960 This project, under the embedded and hybrid systems program (EHS), investigates a surprisingly simple method for integrating process-algebraic techniques with hybrid automaton-based techniques for creating a mathematical foundation upon which real programming languages for hybrid and embedded systems can be based. More specifically, it addresses a new class of hybrid systems which can reconfigure themselves to handle different physical tasks at different times, yet operating concurrently. Very little progress has been achieved to date on such problems. This research investigates a hybrid extension of Milner's pi-calculus to allow processes written in this language to interact with continuous environments. The extension is the phi-calculus. The reasons for pursuing this approach are as follows. (1) The phi-calculus is believed to subsume and properly extend most of the current versions of hybrid systems; for example, hybrid automata hybrid I-O automata hybrid Petri nets, and HybridCC; (2) The goal is to be able to model distributed logical control and interaction with continuous processes in a principled structural way. The pi-calculus, using its algebraic process-structuring primitives, has been shown to be a rich language in which many interesting discrete concurrent phenomena can be expressed: a language for, and theory of, communicating processes which can reconfigure themselves; a language in which distributed objects and classes can be defined; and a language and theory capable not only of expressing interaction, but arbitrary computation, in that the lambda-calculus of Church can be translated into it; (3) This all suggests that successful hybrid versions of algebraic calculi will have novel and elegant ways of expressing hybrid systems --possibilities for distributed control which would be awkward, if not impossible, to express in current formalisms.