Janos Sztipanovits ISIS-Vanderbilt University

1. Frameworks and Tools for High-Confidence Design of Adaptive, Distributed Embedded Control Systems - Project Overview - Janos Sztipanovits ISIS-Vanderbilt University MURI Year 3 Review Meeting Frameworks and Tools for High-Confidence Design of Adaptive, Distributed Embedded Control Systems UC Berkeley, Berkeley, CA December 2, 2009

2. Team • Vanderbilt • Sztipanovits (PI), Karsai, Kottenstette, NeemaPorter, Hemingway, Nile • UC Berkeley • Tomlin (PI), Lee, Sastry, Ding, Gillula, Gonzales, Huang, Leung, Lickly, Mahdl, Latronico, Shelton, Tripakis, Vitus • CMU • Krogh (PI), Clarke, PlatzerJain, Lerda, Bhave, Maka • Stanford • Boyd (PI)Wang

3. Objectives • Development of a theory of deep composition of hybrid control systems with attributes of computational and communication platforms • Development of foundations for model-based software design for high-confidence, networked embedded systems applications. • Composable tool architecture that enables tool reusability in domain-specific tool chains • Experimental research Long-Term PAYOFF: Decrease the V&V cost of distributed embedded control systems

4. Agenda 9:00 – 9:05 am Introductions 9:05 - 9:15 am Project Overview Janos Sztipanovits 9:15 – 10:00 am Overview of Hybrid Control Design Challenges and Solutions Claire Tomlin and Shankar Sastry 10:00 – 10:45am Model-Integrated Tool Chain for High Confidence Design Gabor Karsai, Joe Porter, Graham Hemingway and Janos Sztipanovits 10:45 - 11:00am Break 11:00 – 11:45 am Correctly Composing Components: Ontologies and Modal Behaviors Edward Lee 11:45 – 12:45pm Model-based Testing and Verification Edmund Clarke, Bruce Krogh, Andre Platzer 12:45 – 1:45pm Lunch 1:45 – 2:15 pm Performance Bounds and Suboptimal Policies for Linear Stochastic Control Yang Wang and Stephen Boyd 2:15 – 2:45 pm Constructive Non-linear Control Design With Applications to Quad-Rotor and Fixed-Wing Aircraft Nicholas Kottenstette 2:45 – 3:30 pm Starmac Experimental Platform Demo Claire Tomlin and Shankar Sastry 3:30 – 3:45 pm Plans for Year 4&5Janos Sztipanovits 3:45 - 4:00 pm Break 4:00 – 4:30 pm Government Caucus 4:30 – 4:45 pm Feedback to the Research Team

5. Overall Undertaking Plant Models and Requirements Scope of the Project: • Development of component technologies in selected areas • Development of model-based design methods • Incrementally building and refining a tool chain for an experimental domain (micro UAV control) • Demonstration of control software development with the tool chain • Experiments SW Architecture Modeling Code Model-Based Design Controller Modeling System-Level Modeling Deployment Modeling Expensive Intractable Fragile X

6. Composition Inside Abstraction Layers • Dynamics: • Properties: stability, safety, performance • Abstractions: continuous time, functions, signals, flows,… Plant Dynamics Models Controller Models Physical design Assumption: Effects of digital implementation can be neglected • Software : • Properties: deadlock, invariants, security,… • Abstractions: logical-time, concurrency, atomicity, ideal communication,.. Software Architecture Models Software Component Code Software design Assumption: Effects of platform properties can be neglected System Architecture Models Resource Management Models • Systems : • Properties: timing, power, security, fault tolerance • Abstractions: discrete-time, delays, resources, scheduling, System/Platform Design

7. Composition Inside Abstraction Layers Controller dynamics is developed without considering implementation uncertainties (e.g. word length, clock accuracy ) optimizing performance. Plant Dynamics Models Controller Models Physical design X Assumption: Effects of digital implementation can be neglected Software architecture models are developed without explicitly considering systems platform characteristics, even though key behavioral properties depend on it. Software Architecture Models Software Component Code Software design X Assumption: Effects of platform properties can be neglected Platform architectruedefines platform configuration, resource management, networking,. Uncertainties introduce time variant delays that may require re-verification of key properties on all levels. System Architecture Models Resource Management Models System/Platform Design

8. Improve Robustness of Controllers Against Implementation Uncertainties Plant Models and Requirements • How should we increase robustness in controller design? • Robust hybrid and embedded systems design (Tomlin, Sastry) • Performance bounds for constrained linear stochastic control (Boyd, Wang) • Constructive nonlinear control design (Kottenstette, Porter) SW Architecture Modeling Code Controller Design Model-Based Design Funcion (Controller) Modeling System-Level Modeling Deployment Modeling

9. Verification and Testing Plant Models and Requirements • How can we exploit heterogeneous abstractions in verification and test generation? • Model-based testing and verification of embedded systems implementations (Clarke, Platzer) • Statistical Probabilistic Model Checking (Zuliani, Clarke) SW Architecture Modeling Code V&V Model-Based Design Funcion (Controller) Modeling System-Level Modeling Deployment Modeling

10. Model-based code generation (2008) Plant Models and Requirements SW Architecture Modeling Code From Models To Code Model-Based Design Funcion (Controller) Modeling System-Level Modeling Deployment Modeling • How to design high-confidence software and systems? • Model-based code generation with partial evaluation (Zhou, Leung, Lee) • Model-based code generation with graph transformation (Karsai) • (Last year results, they are built in the tools.)

11. Progress towards integrated model-based design flow AIRES Meta-Model ESML  AIF CFGMeta-Model ECSL-DP Meta-Model ESML-  CFG PRISM ESML PRISM Meta-Model Model-Based Design Plant Models and Requirements • How can we integrate model-based design flows? • Correctly composing components (Lee) • Model-integrated tool chain for high confidence design (Karsai, Porter, Hemingway, DeBusk and Sztipanovits) • StarMac Experimental platform (Tomlin, Sastry) SW Architecture Modeling Code Model-Based Design Funcion (Controller) Modeling System-Level Modeling Deployment Modeling

12. Starmac Experimental PlatformQuadrotor aircraft developed by co-PI Claire Tomlin Requires integration of legacy and custom components.

13. Experimental Set Up • A mobile sensor network: • A set of vehicles, each with a set of sensors for its own navigation and control, as well as for sensing its environment (such as target range or bearing) • Computation is distributed, and limited to the processors on board the vehicles (no central computer) • Communication between subsets of vehicles (limited by range or geography) available • Collision avoidance needed between vehicles • Humans share control with automation • Focus on algorithms for autonomous search: • Unexploded ordinance detection • Beacon tracking scenarios • RFID tracking • Survey of disaster areas • Search and rescue • Biological studies, animal monitoring

14. Accomplishment Highlights 1/2 • New results in hybrid control system design using reachable set analysis. Methodology for computing reachable sets using quantized inputs over discrete time steps has been developed and implemented for an aircraft collision avoidance example. (Tomlin, Sastry) • Use of reachable set analysis in complex control law design. (Tomlin) • We have extended our approach for integrated software model checking in the loop to the case of nonlinear dynamic plant models using the concept of bisimulation functions for nonlinear systems (Krogh) (not presented at the review) • New algorithm for the formal verification of curved flight collision avoidance (Clarke, Platzer) • New algorithm and method for statistical probabilistic model checking and its application to Simulink/Stateflow models (Clarke, Zuliani) • Extension of passivity based approach for controller design to fixed-wing aircrafts. (Kottenstette)

15. Accomplishment Highlights 2/2 • New results in introducing ontology information using Hindley-Milner type theories in modeling environments (Lee) • New results in handling time in hierarchical modal models (Lee) • Integrated tool chain for model-based generation of embedded flight controller on distributed computing platform. Guaranteed stability against implementation induced timing uncertainties and verified schedulability on time-triggered platform. • Demonstration of roundtrip engineering between physical and implementation layers: physical models are used for code generation and implementation models are used for updating physical models. • Demonstration of practical use of reachable set analysis in acrobatic maneuver design and multi-vehicle collision avoidance for the STARMAC quadrotor helicopter testbed.

16. Collaboration • The team members work together extensively in many areas in this project and outside of the project • Many examples for joint work among research teams • Forms of collaborations: • Bi-weekly/monthly telecons • Researcher and graduate student visits • Free flow of ideas, methods and tools

17. Transitioning • The Ptolemy II source tree now is available via CVS. The team actively works on transitioning research results to the following companies : • Lockheed Martin • National Instrument • Vanderbilt’s MIC tool suite (GME, GReAT, UDM, OTIF) had a major release in 2009. GME supports now large scale model management and concurrent modeling. The releases are available through the ISIS download site. • Vanderbilt continued working with GM, Raytheon, LM and BAE Systems research groups on transitioning model-based design technologies into programs. • Vanderbilt continued working with Boeing’s FCS program on applying the MIC tools for precise architecture modeling and systems integration. • Active collaboration with TTTech, University of Vienna. • Collaboration started with VERIMAG.on integrating BIP in the tool chain. • UC Berkeley’s reachable set tools are transitioned to the following institutions: • Microsoft Research • NASA Ames

18. Plans for Years 4&5 • Networked Control System Design • Distributed control/multi agent systems • Dynamic state estimation and mode switching • Robustness against network effects • More realistic channel models • Managing effects from network layer • Verification and Testing • Generation of formal representations from models • Order reduction using hybrid bisimulation • Compositional specification of heterogeneous components • Tools • Integrated, heterogeneous tool chains • Complete path from virtual prototyping to physical implementation • Additional design aspects: fault management, bridge to security • Experiments • Extension of scope and complexity

19. Frameworks and Tools for High-Confidence Design of Adaptive, Distributed Embedded Control Systems • Long-Term PAYOFF: Decrease the V&V cost of distributed embedded control systems • OBJECTIVES • Development of a theory of deep composition of hybrid control systems with attributes of computational and communication platforms • Development of foundations for model-based software design for high-confidence, networked embedded systems applications. • Composable tool architecture that enables tol reusability in domain-specific tool chains • Experimental research Control Design Implementation Design Modeling Languages Models Model Transformation Model Translators Model-based Code Generators if (inactiveInterval != -1) { int thisInterval = (int)(System.currentTimeMillis() - lastAccessed) / 1000; if (thisInterval > inactiveInterval) { invalidate(); ServerSessionManager ssm = ServerSessionManager.getManager(); ssm.removeSession(this); } } } private long lastAccessedTime = creationTime; /** * Return the last time the client sent a Analysis tools Platforms • APPROACH/TECHNICAL CHALLENGES • Guaranteed behavior of distributed control software using the following approaches: (1) extension of robust controller design to selected implementation error categories (2) providing “certificate of correctness” for the controller implementation (3) development of semantic foundation for tool chain composition (4) introducing safe computation models that provide behavior guarantees • ACCOMPLISHMENTS/RESULTS • See Presentations • FUNDING ($K)—Show all funding contributing to this project • FY06FY07FY08FY09FY10FY11 • AFOSR Funds 479 986 989 547 • Option 465 995 529 • TRANSITIONS • Strong link to industry: Boeing, BAE Systems, Raytheon, GM, MathWorks, National Instruments, TTTech • Industry affiliate programs: CHESS, ESCHER, GMLab. • STUDENTS, POST-DOCS • 9 graduate students (MURI) + student groups from other projects • LABORATORY POINT OF CONTACT • Dr William M. McEneaney, AFRL/AFOSR • Dr Fariba Fahroo, AFRL/AFOSR • Dr. David B. Homan , Civ AFRL/RBCC, WPAFB, OH

20. Starmac Platform LIDAR URG-04LX 10 Hz ranges RS232 115 kbps PC/104 Pentium M1GB RAM, 1.8GHz Est. & control WiFi 802.11g+ ≤ 54 Mbps USB 2 480 Mbps Stereo Cam Videre STOC 30 fps 320x240 Firewire 480 Mbps RS232 GPS Superstar II 10 Hz UART 19.2 kbps Stargate 1.0 Intel PXA25564MB RAM, 400MHz Supervisor, GPS WiFi 802.11b ≤ 5 Mbps CF 100 Mbps UART115 Kbps UART IMU 3DMG-X1 76 or 100 Hz UART 115 kbps Start with controller Robostix Atmega128 Low level control Ranger SRF08 13 Hz Altitude I2C 400 kbps PPM100 Hz Analog Expand to supervisor Ranger Mini-AE 10-50 Hz Altitude Beacon Tracker/DTS 1 Hz ESC & Motors Phoenix-25, Axi 2208/26 Finally to host Timing/Analog

21. Platform Extensions Gumstix TTTech Soekris Linux w/ 3xEthernet TT Virtual Machine on standard UDP and Linux No fault tolerance (yet) • MPC 555 micros • TTP/C comm • TTTech Software tools • Fault-tolerance