1. Overview of CHESS Center for Hybrid and Embedded Software Systems
Edward A. Lee
Robert S. Pepper Distinguished Professor CHESS Director UC Berkeley
Berkeley, CA
March 30, 2009

2. University of California at Berkeley
Berkeley Engineering
UC Berkeley has one of the best public engineering schools in the world.

3. Overview of EECS at Berkeley

4. Design Sciences Research Area
Faculty:
Elad Alon
Bernhard Boser
Robert K. Brayton
Robert W. Brodersen
Stephen E. Derenzo
Paul R. Gray
Thomas A. Henzinger
Kurt Keutzer (coordinator)
Andreas Kuehlmann
Ernest S. Kuh
Edward A. Lee
George Necula
Clark Nguyen
Ali Niknejad
Borivoje Nikolic
Albert Pisano
Kameshwar Poolla
Jan M. Rabaey
Alberto Sangiovanni-Vincentelli
Sanjit A. Seshia
Claire Tomlin
John Wawrzynek
Electronic Design Automation
Algorithms and techniques to support computer-aided design and optimization of complex hardware and software systems.
Embedded Software Systems
Models of computation, specification languages, real-time systems, hardware and software synthesis and compilation for electronic systems.
Modeling and Verification
Models of hardware and software systems together with analysis techniques that identify design flaws, performance problems, and vulnerabilities.

5. Chess: Center for Hybrid and Embedded Software Systems
This center, founded in 2002, blends systems theorists and application domain experts with software technologists and computer scientists.
Principal Investigators
Thomas Henzinger (EPFL)
Edward A. Lee (Berkeley)
Alberto Sangiovanni-Vincentelli (Berkeley)
Shankar Sastry (Berkeley)
Janos Sztipanovits (Vanderbilt)
Claire Tomlin (Berkeley)
Executive Director
Christopher Brooks
Associated Faculty
David Auslander (Berkeley, ME)
Ahmad Bahai (Berkeley)
Ruzena Bajcsy (Berkeley)
Gautam Biswas (Vanderbilt)
Ras Bodik (Berkeley, CS)
Bella Bollobas (Memphis)
Karl Hedrick (Berkeley, ME)
Gabor Karsai (Vanderbilt)
Kurt Keutzer (Berkeley)
George Necula (Berkeley, CS)
Koushik Sen (Berkeley, CS)
Sanjit Seshia (Berkeley)
Jonathan Sprinkle (Arizona)
Masayoshi Tomizuka (Berkeley, ME)
Pravin Varaiya (Berkeley)
Applications
Air traffic control
Avionics
Automotive
Building systems
Factory automation
Instrumentation
Medical systems
Process control
Synthetic biology
Test & measurement
the Berkeley directors of Chess
Some Research Projects
Precision-timed (PRET) machines
Distributed real-time computing
Systems of systems
Theoretical foundations of CPS
Hybrid systems
Design technologies
Verification
Intelligent control
Modeling and simulation

6. Hybrid Systems Models Where it started
A model of a spring-mass system with collisions, modeled in Ptolemy II:
Consider the velocity of each mass. Is it continuous? What about the acceleration?
Toyota test cell at Berkeley used to experiment with hybrid systems models.

7. Cyber-Physical Systems (CPS) Where it is going
CPS: Orchestrating networked computational resources with physical systems.

8. The CPS Vision
Networked computers have already changed the way humans communicate and manage information. The change we envision is to the way humans manage their physical environment, including for example transportation, energy, health, and environmental quality. This change requires computing and networking technologies to embrace not just information, but also physical dynamics. The impact of this change could well rival that of the information revolution.

9. Some CPS applications:
Dec. 11, 2006: Dancers in Berkeley dancing in real time with dancers in Urbana-Champagne (Prof. Bacjsy’s group)
telepresence
unoccupied air/space vehicles
distributed physical games
traffic control and safety
financial networks
medical devices and systems
assisted living and elder care
advanced automotive systems
energy conservation
environmental control
aviation systems
critical infrastructure (power, water)
distributed robotics
military systems
smart structures
biosystems (morphogenesis,…)
Potential impact
social networking and games
safe/efficient transportation
fair financial networks
integrated medical systems
distributed micro power generation
military dominance
economic dominance
disaster recovery
energy efficient buildings
alternative energy
pervasive adaptive communications
distributed service delivery …

10. Example: Toyota autonomous vehicle technology roadmap
Source: Toyota Web site

11. Where CPS Differs from the traditional 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.

12. CPS is Multidisciplinary
Computer Science:
Carefully abstracts the physical world
System Theory:
Deals directly with physical quantities
Cyber Physical Systems:
Computational +
Physical

13. CPS is Multidisciplinary

14. Some of the CPS Research in Chess
Foundations: Timed computational semantics.
Bottom up: Embedded processors (PRET).
Top down: Distributed real-time systems (PTIDES).
Holistic: Scalable model-based design.
Applications: Air traffic control.

15. Object Oriented vs. Actor Oriented Software Components
class name
data
methods
call
return
What flows through an object is sequential control
The established: Object-oriented:
Things happen to objects
The alternative: Actor oriented:
actor name
data (state)
ports
Input data
parameters
Output data
What flows through an object is evolving data
Actors make things happen

16. Timed Software Semantics
super-dense time
concurrent actor-oriented models
abstraction
s  S N
Causal systems operating on signals are usually naturally (Scott) continuous.
fixed-point semantics

17. Papers:
[1] Lee and Matsikoudis, "The Semantics of Dataflow with Firing," in From Semantics to Computer Science: Essays in memory of Gilles Kahn, Cambridge 2009.
[2] Ye Zhou and Edward A. Lee. "Causality Interfaces for Actor Networks," ACM Trans. on Embedded Computing Systems, April 2008.
[3] Liu and Lee, "CPO Semantics of Timed Interactive Actor Networks,” Theoretical Computer Science 409 (1): pp ,
[4] Lee, " Application of Partial Orders to Timed Concurrent Systems," article in Partial order techniques for the analysis and synthesis of hybrid and embedded systems, in CDC 07.
[5] Lee and Zheng, "Leveraging Synchronous Language Principles for Heterogeneous Modeling and Design of Embedded Systems," EMSOFT ’07.
[6] Liu, Matsikoudis, and Lee. "Modeling Timed Concurrent Systems," CONCUR ’06.
[7] Cataldo, Lee, Liu, Matsikoudis and Zheng "A Constructive Fixed-Point Theorem and the Feedback Semantics of Timed Systems," WODES'06
etc. ...
Results
Software:
Ptolemy II realizes a number of timed concurrent models of computation (MoCs) with well-founded rigorous semantics.
Ph.D. Theses:
[1] Haiyang Zheng, "Operational Semantics of Hybrid Systems," May 18, 2007.
[2] Ye Zhou, "Interface Theories for Causality Analysis in Actor Networks," May 15, 2007.
[3] Xiaojun Liu, "Semantic Foundation of the Tagged Signal Model," December 20, 2005.

18. Ptolemy II: Our Laboratory for Actor-Oriented Models of Computation
Concurrency management supporting dynamic model structure.
Director from an extensible library defines component interaction semantics or “model of computation.”
Type system for transported data
Extensile, behaviorally-polymorphic component library.
Visual editor supporting an abstract syntax

19. Some of the CPS Research in Chess
Foundations: Timed computational semantics.
Bottom up: Embedded processors (PRET).
Top down: Distributed real-time systems (PTIDES).
Holistic: Scalable model-based design.
Applications: Air traffic control.

20. Bottom Up: Embedded Processors
Precision-Timed (PRET) Machines
Make temporal behavior as important as logical function.
Timing precision with performance: Challenges:
Memory hierarchy (scratchpads?)
Deep pipelines (interleaving?)
ISAs with timing (deadline instructions?)
Multicore (dedicated I/O & real-time processors?)
Predictable memory management (Metronome?)
Languages with timing (discrete events? Giotto?)
Predictable concurrency (synchronous languages?)
Composable timed components (actor-oriented?)
Precision networks (TTA? Time synchronization?)
See S. Edwards and E. A. Lee, "The Case for the Precision Timed (PRET) Machine," in the Wild and Crazy Ideas Track of the Design Automation Conference (DAC), June 2007.

21. PRET Project (Berkeley, Columbia)
Funding from NSF, Toyota, National Instruments, plus cooperation with Xilinx, Synfora, and Tidorum
Staffing:
Edward A. Lee (UCB PI)
Stephen Edwards (Columbia co-PI)
Jan Rabaey (UCB co-PI)
John Wawrzynek (UCB co-PI)
Christopher Brooks (Technical staff)
Hiren Patel (postdoc)
Hugo Andrade (NI VIF)
Shanna-Shaye Forbes (UCB grad student)
Sunjun Kim (Columbia grad student)
Ben Lickly (UCB grad student)
Isaac Liu (UCB grad student)

22. Some of the CPS Research in Chess
Foundations: Timed computational semantics.
Bottom up: Embedded processors (PRET).
Top down: Distributed real-time systems (PTIDES).
Holistic: Scalable model-based design.
Applications: Air traffic control.

23. PTIDES: Programming Temporally Integrated Distributed Embedded Systems
Distributed execution under DE semantics, with “model time” and “real time” bound at sensors and actuators.
Output time stamps are ≤ real time
Input time stamps are ≥ real time
Input time stamps are ≥ real time
Output time stamps are ≤ real time

24. PTIDES Project
Funding from NSF, Agilent, HSBC, IBM, Toyota, and the State of California MICRO program, in cooperation with the University of Salzburg, Austria.
Staffing:
Edward A. Lee (UCB PI)
Christopher Brooks (Technical staff)
Patricia Derler (Univ. Salzburg grad student)
Slobodan Matic (postdoc)
Thomas Feng (UCB grad student)
Ben Lickly (UCB grad student)
Stefan Resmerita (Univ. Salzburg technical staff)
Yang Zhao (UCB grad student, Google technical staff)
Jia Zou (UCB grad student)

25. Some of the CPS Research in Chess
Foundations: Timed computational semantics.
Bottom up: Embedded processors (PRET).
Top down: Distributed real-time systems (PTIDES).
Holistic: Scalable model-based design.
Applications: Air traffic control.

26. Hierarchical Multimodeling Hierarchical compositions of models of computation. Maintaining temporal semantics across MoCs is a main challenge.

27. Multi-View Modeling: Distinct and separate models of the same system are constructed to model different aspects of the system.
Functional model in Statecharts
Verification
model in SMV
Deployment
model in
Ptolemy II
Functional
model in
Ptolemy II
This example is a test case for a collaborative project with Lockheed-Martin
Reliability
model in
Excel

28. “Model Engineering” Project
Funding from Army Research Office, Air Force Research Office, Bosch, Lockheed-Martin.
Staffing:
Edward A. Lee (UCB PI)
Christopher Brooks (Technical staff)
Teale Fristoe (Technical staff)
Chihong (Partrick) Cheng (National Taiwan University, Taipei/Berkeley exchange student)
Thomas Huining Feng (UCB grad student)
Jackie Mankit Leung (UCB grad student)
Eleftherios Matisikoudis (UCB grad student)

29. Some of the CPS Research in Chess
Foundations: Timed computational semantics.
Bottom up: Embedded processors (PRET).
Top down: Distributed real-time systems (PTIDES).
Holistic: Scalable model-based design.
Applications: Air traffic control.

30. FACET,
NASA Ames

31. Oakland Center
FACET,
NASA Ames

32. 1. Automated Separation Assurance
2.5 miles
1000 ft
(250 ft radius near airports)

33. Hybrid Systems Approach
Holding Pattern
Decrease Speed
Hold Speed
Increase Speed
Shortcut
Detour
Vector for Spacing
Vector for Spacing
10/1/2008
HSL Group Meeting 33 33

34. 2. Mixed Initiative Control
Strategic Planning
Planning Horizon
States
Costs/Goals
Outputs
Planning Agents
Aggregate Over Sector
Inflow/Outflow Management
Costs & Goals For Tactical Planner
Hours
Human
Tactical Planning
Planning Horizon
States
Costs/Goals
Outputs
Automation
Aircraft Dynamics
Set By Strategic Planner
Aircraft Vectoring Commands
Minutes
10/1/2008
HSL Group Meeting 34 34

35. Verification in autopilots
what the pilot sees

36. 3. Super-dense airspaces

37. early morning (departures)
NY Center 31 22
La Guardia
Kennedy
Newark
Teterborough
13’s
22’s
Priority over Kennedy
early morning (departures)
29’s 4 13
31’s
4’s 19 1 24 6
16 – 4 = 12 possible configs

38. Research as a Business Our Business Model:
Maximize the impact of our work, and the rest follows

39. Chess Industrial Partnerships
Close interaction between academic research and industrial experience, often involving frequent deep technical interactions.
Facilitate the creation and transfer of modern, "new economy" software technology methods and tools to "old economy" market sectors.
Focus on industries where embedded software plays a central role, such as:
aerospace
automotive
Instrumentation, test, and measurement

40. Options for Funding Research
Gifts
Quasi-gifts (CADCAM, BEECSA, ...)
Center memberships
Contracts
Center memberships have proved far more effective than the alternatives.

41. Intellectual Property in CHESS
Commitment is:
Software will be open source
Patents will be rare

42. IP Principles Address researcher concerns Address company concerns:
Maximize the impact of the work
Freedom to publish papers
Freedom to release open source software
No obligation to patent results
Ability to patent results
Minimal obstacles to commercialization
Address company concerns:
Value for the money
Protection from being “locked out” of research results
Viable VIF agreements
Desire to “expense” contributions

43. Intellectual Property Rights From Appendix C of the CHESS Agreement
“The objective of CHESS is to maximize the impact of its research. To achieve this, CHESS will maintain an open atmosphere that encourages early and frequent publication and other public dissemination of research results. Software will primarily be released using an open source license such as the Berkeley Software Distribution (BSD) License. Selected software, such as those subject to third party obligations, may be released under different licenses.” 
“Patents are expected to be rare. . .”

44. The BSD License: Used for most software
Copyright (c) YEAR The Regents of the University of California.
All rights reserved.
Permission is hereby granted, without written agreement and without license or royalty fees, to use, copy, modify, and distribute this software and its documentation for any purpose, provided that the above copyright notice and the following two paragraphs appear in all copies of this software.
IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.

45. Spinoffs of Ptolemy Software
Agilent ADS: Leading design software for analog, RF, and mixed-signal design, primarily targeted to wireless systems development, based on Ptolemy Classic.
Cal actor design language, adopted by MPEG for specification of coding standards, and used by Thales, Xilinx, and others for FPGA and multicore software design.
iSencia Passerelle is based on Ptolemy II and is used to prepare experiments for the Soleil synchrotron.
Kepler: A System for Scientific Workflows, is a cross-project collaboration to develop open source tools for Scientific Workflows and is based on the Ptolemy II.
Mirabilis Design VisualSim, built on top of Ptolemy II, does performance analysis and system architecture, rapid system modeling and hardware/software tradeoff analysis.
ML Design Technologies’ MLDesigner, is a platform that leverages Ptolemy Classic for modeling and analyzing the architecture, function and performance of high level system.
And more: Boeing, Bosch, Cadence, Lockheed Martin, Research in Motion, Thales (ArrayOL), VPI Systems, White Eagle Technologies, etc.

46. CHESS Industrial Membership Levels
Affiliate
> $75k/year
Affiliate membership includes the following benefits:
Invitation to periodic reviews of CHESS.
Access to selected internal CHESS websites.
Access to publications, reports and presentations by CHESS researchers.
Access to students and faculty in CHESS.
An annual research report of the activities of CHESS.
Advance notice of intellectual property created by CHESS.
Intellectual property access as defined in the agreement. (See Appendix C(1))
Small or Minority-Owned Business
> $10k/year
All of the benefits of an Affiliate
Partner
> $150k/year
All of the benefits of an Affiliate, plus the following:
Opportunity to place visitors, as Visiting Industrial Fellows (VIF) at the University.
Selected early access to software developed by CHESS.
Premium Partner
> $300k/year
All of the benefits of a Partner, plus the following:
Intellectual property access as defined in the agreement.
Upon request, an annual private research review meeting at the University or at a mutually agreeable site.

47. Conclusion
Chess has a rich portfolio of research projects and an established track record of working effectively with industry to maximize the impact of the work.