Session 8: DES Control

Session chair: Tim Kelly 

14:00 - 15:30 Friday 6th September 2013
14:00 Discrete Control for Reconfigurable FPGA-based Embedded Systems
Authors: Xin An, Eric Rutten, jean-philippe diguet, Nicolas Le Griguer, Abdoulaye Gamatie
Abstract: This work presents an application of discrete controller synthesis (DCS) techniques to a class of dynamically reconfigurable embedded computing systems, and contributes to the general approach of control for feedback computing. We propose a general model for applications defined as data-flow graphs of computing tasks, and target execution architectures that are dynamically partially reconfigurable Field Programmable Gate Arrays (FPGAs). We define our model in terms of parallel automata. Then, we encode relevant scheduling and control requirements in terms of a DCS problem w.r.t. multiple constraints and objectives. We take into account the system reconfiguration overhead, and the resulting controller is able to make decisions by foreseeing their impact on future requests. We validate our approach by using the BZR programming language and Sigali tool for modelling and simulations, with a video processing system implementation on a specific FPGA platform.
14:30 Abstraction-based Supervisory Control for Reconfigurable Manufacturing Systems
Authors: Harith M. Khalid, Mustafa Sancay Kirik, Klaus Schmidt
Abstract: Reconfiguration control for discrete event systems (DES) is concerned with the realization of different system configurations by modification of the supervisory control loop. In this paper, we study the reconfiguration supervisor design for reconfigurable manufacturing systems (RMS) that comprise multiple components. We construct a modular supervisor for each configuration and system component in order to realize each active configuration and to quickly change between configurations. Different from the existing literature that is focused on monolithic design, our method is abstraction-based, and, hence applicable to large-scale DES. 
15:00 State-Stability Analysis of Discrete Event Systems using Petri-net Branching Processes
Authors: Alberto Lutz-Ley, Ernesto Lopez-Mellado
Abstract: This paper studies fault tolerance of concurrent discrete event systems (DESs) through the stability analysis of Interpreted Petri nets (IPN) models. An efficient method for determining state stability of safe IPN models is proposed. The method is based on the analysis of the sequentially secure branching process of the DES model, which is a finite representation of a PN unfolding: a sufficient condition for stability and an algorithm for deciding the property are presented.