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Final cyber physical system (1)

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INTRODUCTION TO CYBER PHYSICAL SYSTEM

Published in: Engineering

Final cyber physical system (1)

  1. 1. • CyberCyber – computation, communication, and control that are discrete, logical, and switched • Physical – natural and human-made systems governed by the laws of physics and operating in continuous time • Cyber-Physical Systems – systems in which the cyber and physical systems are tightly integrated at all scales and levelsChange from cyber merely appliquéd on physical • Change from physical with off-the-shelf commodity “computing as parts” mindset • Change from ad hoc to grounded, assured development
  2. 2. Characterstics of CPSs
  3. 3. MODULES IN CPS
  4. 4. The embedded systems problem: • Embedded software is software on small computers. The technical problem is one of optimization (coping with limited resources). The CPS problem: • Computation and networking integrated with physical processes. The technical problem is managing time and concurrency in networked computational systems.
  5. 5. Crosses Interdisciplinary Boundaries package org.apache.tomcat.session; import org.apache.tomcat.core.*; import org.apache.tomcat.util.StringManager; import java.io.*; import java.net.*; import java.util.*; import javax.servlet.*; import javax.servlet.http.*; /** * Core implementation of a server session * * @author James Duncan Davidson [duncan@eng.sun.com] * @author James Todd [gonzo@eng.sun.com] */ public class ServerSession { private StringManager sm = StringManager.getManager("org.apache.tomcat.session"); private Hashtable values = new Hashtable(); private Hashtable appSessions = new Hashtable(); private String id; private long creationTime = System.currentTimeMillis();; private long thisAccessTime = creationTime; private long lastAccessed = creationTime; private int inactiveInterval = -1; ServerSession(String id) { this.id = id; } public String getId() { return id; } public long getCreationTime() { return creationTime; } public long getLastAccessedTime() { return lastAccessed; } public ApplicationSession getApplicationSession(Context context, boolean create) { ApplicationSession appSession = (ApplicationSession)appSessions.get(context); if (appSession == null && create) { // XXX // sync to ensure valid? appSession = new ApplicationSession(id, this, context); appSessions.put(context, appSession); } // XXX // make sure that we haven't gone over the end of our // inactive interval -- if so, invalidate and create // a new appSession return appSession; } void removeApplicationSession(Context context) { appSessions.remove(context); } /** * Called by context when request comes in so that accesses and * inactivities can be dealt with accordingly. */ void accessed() { // set last accessed to thisAccessTime as it will be left over // from the previous access lastAccessed = thisAccessTime; thisAccessTime = System.currentTimeMillis(); } void validate() Software Control • Disciplinary boundaries need to be realigned • New fundamentals need to be created • New technologies and tools need to be developed • Education need to be restructured
  6. 6. Computing System Composition Domain Physical instantiation Physical System Composi tion Domain • “Cyber” Models • Modeling Languages – Structure – Behaviors • Mathematical Domains – traces/state variables – no reference semantics or “semantic units” • Physical Models • Modeling Languages – Structure – Behaviors • Physical Laws – Physical variables – Physical Units
  7. 7. • Transform how we interact with the physical world just like the internet transformed how we interact with one another. – Transcend space – Control the physical environment remotely • Building CPSs that integrate computational and physical objects requires new systems science foundations. – Fusion of physical and computational sciences
  8. 8. • Rich time models instead of sequencing • Behavioral invariants instead of end results • Functionality through interactions of ongoing behaviors instead of sequence of actions • Component architectures instead of procedural abstraction • Concurrency models with partially ordered instead of linearly ordered event sets  Precise interaction and coordination protocols  Hugely increased system size with controllable, stable behavior  Dynamic system architectures (nature and extent of interaction can be modified)  Adaptive, autonomic behavior  Self-descriptive, self monitoring system architecture for safety guarantees.
  9. 9. POSTER
  10. 10. THANK YOU!

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