1 / 19

Electronic Communications of the EASST Volume 21 ( 2009)

Electronic Communications of the EASST Volume 21 ( 2009).

ronli
Download Presentation

Electronic Communications of the EASST Volume 21 ( 2009)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Electronic Communications of the EASST Volume 21 (2009) An Architectural Approach to the Design and Analysis of Cyber-Physical SystemsAkshay Rajhans, Shang-Wen Cheng, Bradley Schmerl, David Garlan, Bruce H. Krogh, Clarence Agbi and Ajinkya BhaveDept. of Electrical and Computer EngineeringSchool of Computer ScienceCarnegie Mellon UniversityPittsburgh, PA USA 15213-3890 Presented By: AyushKhandelwal 00940178

  2. About the Authors.. • AkshayRajhans: Working on model-based design and formal analysis of cyber-physical systems • Shang-Wen Cheng: Currently as Software Engineer at the NASA Jet Propulsion Laboratory • Bradley Schmerl: Senior Systems Scientist, School of Computer Science Carnegie Mellon University • David Garlan: Professor of School of Computer Science. Research areas as formal methods, domain-specific software architectures and programming environments. • Bruce H. Krogh: Research Area Signals/Control • Clarence Agbi: Secretary for PhD in Electrical and Computer Engineering at Carnegie Mellon University • AjinkyaBhave: Working in The Robotics Institute at Carnegie Mellon University

  3. Acknowledgments: This work was supported in part by National Science Foundation (NSF) under grant no. CNS0834701 and by Air Force Office of Scientific Research (AFOSR) under contract no. FA9550-06-1-0312.

  4. CONTENT 1. Abstract2.Introduction3.Previous Works4.CPS Architectural Stylea)Cyber Familyb)Physical Family c) Cyber-physical interface family5. Example6. Behavioral Annotations7. Behavioral Verification8. Discussion

  5. ABSTRACT This paper presents an extension of existing software architecture tools to model physical systems, their interconnections, and the interactions between physical and cyber components. A new CPS architectural style is introduced to support the principled design and evaluation of alternative architectures for cyber physical systems (CPSs). The implementation of the CPS architectural style in Acme Studio includes behavioral annotations on components and connectors using either finite state processes (FSP) or linear hybrid automata (LHA) with plug-ins to perform behavior analysis using the Labeled Transition System Analyzer (LTSA) or Polyhedral Hybrid Automata Verifier (PHAVer), respectively. The CPS architecturalstyle and analysis plug-ins are illustrated with an example.

  6. CPS is based on…. • Disparate Mathematical Formalisms • Dissimilar Methodologies in Engineering and Computer Science Goal… To create an extensible framework within which a comprehensive set of design tools can be created

  7. Previous Works.. • Software Architecture model: • Components • Connectors • Standardized Notations: • UML 2.0 • SysML • AADL

  8. Contd.. Architectural Behavior Using:AlgebrasState MachinesProvides..CompatibilityPerformanceReliabilitySecurityReusabilitySoftware Architecture for Embedded and Control Systems using Languages such as Meta-H ,AADL

  9. CPS ARCHITECTURAL STYLE • Represent systems at a higher level • Challenge of treating cyber and physical elements equally • Usage of Acme ADL • Architectural style is represented as a family • Three families • Cyber Family • Physical family • Cyber-physical interface family

  10. Cyber Family • Data Stores • Computation • IO Interfaces • Types of Cyber Connectors • Call-return Connector • Publish Subscribe Connector

  11. Physical family: • Challenges in developing representation: • Should not have all the details required for a full simulation • Also, should correspond to intuitive notions of physical dynamics • Solution: • Introduction of components and connectors in energy view of Physical systems • Examples : Bond Graphs, Langrangian Mechanics

  12. Physical family Contd… • Physical Component: • Sources • Energy storage • Physical transducers • Physical Connector: • Power flow • Shared variable • Measurement

  13. Cyber-Physical Interface Family: • Inherits elements of cyber and physical families and adds new elements to bridge the gap. • Simple Interfaces: • P2C connector • C2P connector • Complex Interfaces • P2C transducer • C2P transducer • Example: intelligent sensor nodes

  14. Example:

  15. Another Example

  16. Behavioral Annotations: • Implemented for behavioral modeling frameworks – • Finite State Processes • Linear Hybrid Automata • Plugins- • Usage :generate analyzable text files from these properties • Plug-in for FSP: Labelled Transition System Analyser • Plug-in for LHA: Polyhedral Hybrid Automaton Verifyer

  17. Example:

  18. Behavioral Verification: Goal : Maintaining Zone 1 temperature close to the thermostat set point Furnace States – Powered Off, Powered On and Heating Challenge : Furnace misses the Heat On command. Solution 1: Usage of Finite State Process and Liveliness property of Labeled Transition System Analyzer and added shutdown notification connector between furnace and thermostat. Challenge: If Furnace is a Dumb Device Solution2:LHA analysis in PHAVer, and using Real Time Clock and Rates of Change of Temperature

  19. Discussion: A new CPS architectural style is proposed with tools for annotating CPS architectures with behavioral models such as finite state processes and linear hybrid automata.

More Related