Please use this identifier to cite or link to this item:
http://hdl.handle.net/11375/21265
Title: | Synthesis Method for Hierarchical Interface-Based Supervisory Control |
Authors: | Dai, Pengcheng |
Advisor: | Leduc, Ryan J. |
Department: | Software Engineering |
Keywords: | synthesis method, hierarchical, interface-based, supervisory control, discrete-event system, HISC, operators |
Publication Date: | Apr-2006 |
Abstract: | <p> Hierarchical Interface-based Supervisory Control (HISC) decomposes a discrete-event system (DES) into a high-level subsystem which communicates with n ≥ 1 low-level subsystems, through separate interfaces which restrict the interaction of the subsystems. It provides a set of local conditions that can be used to verify global conditions such as nonblocking and controllability. As each clause of the definition can be verified using a single subsystem, the complete system model never needs to be stored in memory, offering potentially significant savings in computational resources.</p> <p> Currently, a designer must create the supervisors for a HISC system himself, and then verify that they satisfy the HISC conditions. In this thesis, we develop a synthesis method that respects the HISC hierarchical structure. We replace the supervisor for each level by a corresponding specification DES. We then do a per level synthesis to construct for each level a maximally permissive supervisor that satisfies the corresponding HISC conditions.</p> <p> We define a set of language based fixpoint operators and show that they compute the required level-wise supremal languages. We then present algorithms that implement the fixpoint operators. We present a complexity analysis for the algorithms and show that they potentially offer significant improvement over the monolithic approach.</p> <p> A large manufacturing system example (estimated worst case state space on the order of 10^22) extended from the AIP example is discussed. A software tool for synthesis and verification of HISC systems using our approach was also developed.</p> |
URI: | http://hdl.handle.net/11375/21265 |
Appears in Collections: | Digitized Open Access Dissertations and Theses |
Files in This Item:
File | Description | Size | Format | |
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Dai_Pengcheng_2006Apr_Masters..pdf | 6.21 MB | Adobe PDF | View/Open |
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