1. Embedded Control System Development with Giotto Thomas A. Henzinger, Benjamin Horowitz, Christoph Meyer Kirsch UC Berkeley

2. Giotto Giotto is a time-triggered and platform independent programming language + compiler + runtime library Giotto aims at hard real-time control applications on distributed platforms (safety-critical applications) Giotto provides an abstract programming model for embedded control system development Giotto runtime library for VxWorks (using timer services, scheduling services, TCP/IP stack)

3. Embedded System Development Control Engineer Control Design Application decomposes designs simulates Software Engineer Platform Giotto Program decomposes implements tests Functionality & Timing Matlab! Giotto!

4. A Giotto Task fSensors State Actuators Frequency 10ms

5. Semantics of a Giotto Task f State Time Task Read @ time t Frequency 10ms Write @ time t+10ms Don’t care SensorsActuators

6. Multiple Giotto Tasks Task QQ t+10ms P t+5mst Don’t care t+5ms Don’t care t

7. Concrete Syntax start slow ( ) { mode slow ( ) period 10 ms entryfreq 1 { taskfreq 1 do int motor1 = P ( bool bump ) ; taskfreq 2 do int motor2 = Q ( int position ) ; exitfreq 2 if position = 5 then fast ( ) ; } mode fast ( ) period 10 ms entryfreq 2 { taskfreq 1 do int motor1 = P ( bool bump ) ; taskfreq 4 do int motor2 = R ( int position ) ; }

8. Compilation Control Engineer Control Design Application decomposes designs simulates Software Engineer Platform Giotto Program decomposes implements tests Functionality & Timing Matlab! Giotto!

9. The Giotto Compiler Giotto Executable Giotto Program Compilation Giotto Runtime Library Distributed Platform Functionality & Timing Scheduling & Communication VxWorks

10. The Giotto Compiler Giotto Compiler Giotto Program Giotto Executable Possible Answers: Giotto Executable Not Schedulable

11. Giotto-Platform Giotto Compiler Hosts, Nets, Performance Giotto Program Giotto-P Program Distributed Platform

12. Giotto-Scheduler Giotto Compiler Task to Host, Priority Hosts, Nets, Performance Giotto Program Giotto-P Program Giotto-PS Program Distributed Platform

13. Giotto-Communication Giotto Program Giotto Compiler Giotto-P Program Distributed Platform Giotto-PS Program Giotto-PSC Program Task to Host, Priority Hosts, Nets, Performance Connection to Net, TDMA

14. The Giotto Runtime Library Giotto Executable Giotto Program Compilation Giotto Runtime Library Distributed Platform Functionality & Timing Scheduling & Communication VxWorks

15. The Giotto Runtime Library Giotto Runtime Library Distributed Platform VxWorks Timer Service Scheduling Service TCP/IP Stack Scheduling & Communication Abstraction Task, Connection Mapping Task Scheduling Scheme TDMA Slots Real-Time OS Services

16. The Giotto Runtime Library Available on VxWorks and x86 targets Current Experimental Robots: –credit card size x86 single board computer running VxWorks –wireless Ethernet –Lego motors, sensors Next Experimental Platform: –unmanned Yamaha helicopters –PC 104 single board computer running VxWorks –wireless Ethernet, GPS, inertial navigation sensor, …

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