Design Contracts for Cyber-Physical Systems: Making Timing Assumptions Explicit

Martin Toerngren, Stavros Tripakis, Patricia Derler and Edward A. Lee

EECS Department
University of California, Berkeley
Technical Report No. UCB/EECS-2012-191
August 21, 2012

http://www.eecs.berkeley.edu/Pubs/TechRpts/2012/EECS-2012-191.pdf

Building Cyber-Physical Systems (CPS) involves several teams of engineers with different backgrounds. We focus on interactions between control engineers and embedded software engineers. Lack of rigorous methodologies for communication and interaction between the two groups has been recognized as an obstacle to the development of dependable and cost-effective CPS. We advocate the use of {\em design contracts} as a step towards bridging this gap. Design contracts act as a medium for communication and interaction between the control and computation/communication design problems in a CPS. The contracts provide a focal point for negotiation and for decision making. Once design contracts have been established, they help to separate the global CPS design problem into two sub-problems, each of which can be tackled separately by the control-engineering and the embedded software teams, thus making the design more tractable and efficient.

We propose a framework of design contracts encompassing (i) concepts relevant to timing constraints and functionality; (ii) a formulation of some popular design approaches as design contracts; and (iii) a process and guidelines on how to choose, derive and employ design contracts. The guidelines place specific emphasis on modeling and simulation support.


BibTeX citation:

@techreport{Toerngren:EECS-2012-191,
    Author = {Toerngren, Martin and Tripakis, Stavros and Derler, Patricia and Lee, Edward A.},
    Title = {Design Contracts for Cyber-Physical Systems: Making Timing Assumptions Explicit},
    Institution = {EECS Department, University of California, Berkeley},
    Year = {2012},
    Month = {Aug},
    URL = {http://www.eecs.berkeley.edu/Pubs/TechRpts/2012/EECS-2012-191.html},
    Number = {UCB/EECS-2012-191},
    Abstract = {Building Cyber-Physical Systems (CPS) involves several  teams of engineers with different backgrounds. We focus on interactions between control engineers and embedded software engineers. Lack of rigorous methodologies for communication and interaction between the two groups has been recognized as an obstacle to the development of dependable and cost-effective CPS. We advocate the use of {\em design contracts} as a step towards bridging this gap. Design contracts act as a medium for communication and interaction between the control and computation/communication design problems in a CPS. The contracts provide a focal point for negotiation and for decision making. Once design contracts have been established, they help to separate the global CPS design problem into two sub-problems, each of which can be tackled separately by the control-engineering and the embedded software teams, thus making the design more tractable and efficient. 

We propose a framework of design contracts encompassing 
(i) concepts relevant to timing constraints and functionality;
(ii) a formulation of some popular design approaches as design contracts; and
(iii) a process and guidelines on how to choose, derive and employ design contracts. The guidelines place specific emphasis on modeling and simulation support.}
}

EndNote citation:

%0 Report
%A Toerngren, Martin
%A Tripakis, Stavros
%A Derler, Patricia
%A Lee, Edward A.
%T Design Contracts for Cyber-Physical Systems: Making Timing Assumptions Explicit
%I EECS Department, University of California, Berkeley
%D 2012
%8 August 21
%@ UCB/EECS-2012-191
%U http://www.eecs.berkeley.edu/Pubs/TechRpts/2012/EECS-2012-191.html
%F Toerngren:EECS-2012-191