SGER: Algebraic Languages for Reconfigurable Hybrid Systems

RoundsCCR-0233960这个项目，在嵌入式和混合系统计划(EHS)下，研究了一种令人惊讶的简单方法，用于将进程代数技术与基于混合自动机的技术相结合，以创建一个数学基础，在此基础上可以为混合和嵌入式系统的真正编程语言提供基础。更具体地说，它针对的是一类新的混合系统，这些系统可以重新配置自己，以在不同的时间处理不同的物理任务，但同时运行。到目前为止，在这类问题上几乎没有取得什么进展。这项研究调查了Milner的圆周率演算的一个混合扩展，以允许用这种语言编写的进程与连续环境交互。推广的是Phi-演算。采用这种方法的原因如下。(1)Phi-演算被认为包含并适当地扩展了当前大多数版本的混杂系统，例如混杂自动机、混合I-O自动机、混杂Petri网和Hybridge CC；(2)目标是能够以原则性的结构化方式对分布式逻辑控制和与连续过程的交互进行建模。Pi-演算，使用它的代数进程结构原语，已经被证明是一种丰富的语言，可以用它来表达许多有趣的离散并发现象：一种用于通信进程的语言和理论，可以重新配置自己；一种可以定义分布式对象和类的语言；以及一种不仅能够表达交互，而且能够表达任意计算的语言和理论，因为Church的lambda演算可以被翻译成它；(3)这都表明，成功的代数演算的混合版本将有新颖而优雅的方式来表达混合系统-分布式控制的可能性将是笨拙的，如果不是不可能的，用当前的形式主义来表达。

RoundsCCR-0233960This project, under theembedded and hybrid systems program (EHS), investigates a surprisingly simple method forintegrating 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 systemswhich 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 bea 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 theorycapable 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.