Design of Discrete-Event Systems Using Templates Lenko Grigorov 1, José Eduardo Ribeiro Cury 2 and Karen Rudie 1 1 Queen’s University, Kingston, Canada 2 Federal University of Santa Catarina, Brazil
June, 2008Grigorov, Cury and Rudie, QueensU & UFSC2 Discrete Event Systems Ramadge and Wonham '86 Model as FSAs System Superviso r events control decisions
June, 2008Grigorov, Cury and Rudie, QueensU & UFSC3 System Robotic armPress
June, 2008Grigorov, Cury and Rudie, QueensU & UFSC4 Requirements Collision prevention Process
June, 2008Grigorov, Cury and Rudie, QueensU & UFSC5 Problem 1: synchronization Collision prevention Process Press
June, 2008Grigorov, Cury and Rudie, QueensU & UFSC6 Problem 2: explicit specs Collision prevention Process
June, 2008Grigorov, Cury and Rudie, QueensU & UFSC7 Supervisors Trivial exampleReal system
June, 2008Grigorov, Cury and Rudie, QueensU & UFSC8 Problem 3: implementation ? Abstract supervisor Programmable Logic Controller (PLC) code for real system (50 states, 200 transitions)
June, 2008Grigorov, Cury and Rudie, QueensU & UFSC9 Conceptual design framework What we really talk about is Event generators Protocols
June, 2008Grigorov, Cury and Rudie, QueensU & UFSC10 Conceptual design framework What we really talk about is Event generators Protocols Santos et al. '01 Active components Passive components Connections between them Simultaneous structural & functional design
June, 2008Grigorov, Cury and Rudie, QueensU & UFSC11 Example diagram PressArmWelder Avoid collision Transport belt Process control
June, 2008Grigorov, Cury and Rudie, QueensU & UFSC12 Example diagram PressArmWelder Avoid collision Transport belt Process control Event synchronization
June, 2008Grigorov, Cury and Rudie, QueensU & UFSC13 Templates (abstract) Abstract common behavior template abstract
June, 2008Grigorov, Cury and Rudie, QueensU & UFSC14 Templates (instantiate) Instantiate existing templates template instantiate
June, 2008Grigorov, Cury and Rudie, QueensU & UFSC15 Templates Faster No need to remodel similar behavior More robust Can be thoroughly tested Easier Graphical conceptual designs
June, 2008Grigorov, Cury and Rudie, QueensU & UFSC16 Process 1.Model templates as FSAs 2.Instantiate graphically the templates 3.Link graphically the events to synchronize the template instances 4.Enter custom PLC code for events 5.Click “GO” to automatically Make implicit specifications explicit Compute modular supervisors Obtain PLC code for download to controller
June, 2008Grigorov, Cury and Rudie, QueensU & UFSC17 1.Model templates as FSAs 2.Instantiate graphically the templates 3.Link graphically the events to synchronize the template instances 4.Enter custom PLC code for events 5.Click “GO” to automatically Make implicit specifications explicit Compute modular supervisors Obtain PLC code for download to controller Process
June, 2008Grigorov, Cury and Rudie, QueensU & UFSC18 1.Model templates as FSAs 2.Instantiate graphically the templates 3.Link graphically the events to synchronize the template instances 4.Enter custom PLC code for events 5.Click “GO” to automatically Make implicit specifications explicit Compute modular supervisors Obtain PLC code for download to controller Process Control engineer Programmer
June, 2008Grigorov, Cury and Rudie, QueensU & UFSC19 Example application Methodology used to design controllers for a robotic testbed at DAS, UFSC
June, 2008Grigorov, Cury and Rudie, QueensU & UFSC20 Benefits of the template design methodology Operates in the standard DES framework Saves time and testing effort Reduces likelihood of errors Facilitates integration of expertise Focuses on conceptual design Supports quick prototyping
June, 2008Grigorov, Cury and Rudie, QueensU & UFSC21 Future work Improve user interface Focus on fast design prototyping Conceptual designs with “placeholder” components Parametrization Scaling of templates Two-way real-time interaction between DES model and PLC
June, 2008Grigorov, Cury and Rudie, QueensU & UFSC22 Our universities