scholarly journals Efficient Symbolic Supervisor Synthesis for Extended Finite Automata

2014 ◽  
Vol 22 (6) ◽  
pp. 2368-2375 ◽  
Author(s):  
Zhennan Fei ◽  
Sajed Miremadi ◽  
Knut Akesson ◽  
Bengt Lennartson
Author(s):  
Ferdie F. H. Reijnen ◽  
Toby R. Erens ◽  
Joanna M. van de Mortel-Fronczak ◽  
Jacobus E. Rooda

AbstractThe development of supervisory controllers for cyber-physical systems is a laborious and error-prone process. Supervisor synthesis enables control designers to automatically synthesize a correct-by-construction supervisor from a model of the plant combined with a model of the control requirements. From the supervisor model, controller code can be generated which is suitable for the implementation on a programmable logic controller (PLC). Supervisors for industrial systems that operate in close proximity to humans have to adhere to strict safety standards. To achieve these standards, safety PLCs (SPLCs) are used. For SPLC implementation, the supervisor has to be split into a regular part and a safety part. In previous work, a method is proposed to automatically split a supervisor model for this purpose. The method assumes that the provided plant model is a collection of finite automata. In this paper, the extension to extended finite automata is described. Additionally, guidelines are provided for modeling the plant and the requirements to achieve a favorable splitting. A case study on a rotating bridge is elaborated which has been used to validate the method. The case study spans all development steps, including the implementation of the resulting supervisor to control the real bridge.


Author(s):  
Berend Jan Christiaan van Putten ◽  
Bram van der Sanden ◽  
Michel Reniers ◽  
Jeroen Voeten ◽  
Ramon Schiffelers

Abstract One of the challenges in the design of supervisors with optimal throughput for manufacturing systems is the presence of behavior outside the control of the supervisor. Uncontrollable behavior is typically encountered in the presence of (user) inputs, external disturbances, and exceptional behavior. This paper introduces an approach for the modeling and synthesis of a throughput-optimal supervisor for manufacturing systems with partially-controllable behavior on two abstraction levels. Extended finite automata are used to model the high abstraction level in terms of system activities, where uncontrollability is modeled by the presence of uncontrollable activities. In the lower abstraction level, activities are modeled as directed acyclic graphs that define the constituent actions and dependencies between them. System feedback from the lower abstraction level, including timing, is captured using variables in the extended finite automata of the higher abstraction level. For throughput optimization, game-theoretic methods are employed on the state space of the synthesized supervisor to determine a guarantee to the lower-bound system performance. This result is also used in a new method to automatically compute a throughput-optimal controller that is robust to the uncontrollable behavior.


2015 ◽  
Vol 52 (2) ◽  
pp. 221-232
Author(s):  
Pál Dömösi ◽  
Géza Horváth

In this paper we introduce a novel block cipher based on the composition of abstract finite automata and Latin cubes. For information encryption and decryption the apparatus uses the same secret keys, which consist of key-automata based on composition of abstract finite automata such that the transition matrices of the component automata form Latin cubes. The aim of the paper is to show the essence of our algorithms not only for specialists working in compositions of abstract automata but also for all researchers interested in cryptosystems. Therefore, automata theoretical background of our results is not emphasized. The introduced cryptosystem is important also from a theoretical point of view, because it is the first fully functioning block cipher based on automata network.


2017 ◽  
Vol 5 (1) ◽  
pp. 8-15
Author(s):  
Sergii Hilgurt ◽  

The multi-pattern matching is a fundamental technique found in applications like a network intrusion detection system, anti-virus, anti-worms and other signature- based information security tools. Due to rising traffic rates, increasing number and sophistication of attacks and the collapse of Moore’s law, traditional software solutions can no longer keep up. Therefore, hardware approaches are frequently being used by developers to accelerate pattern matching. Reconfigurable FPGA-based devices, providing the flexibility of software and the near-ASIC performance, have become increasingly popular for this purpose. Hence, increasing the efficiency of reconfigurable information security tools is a scientific issue now. Many different approaches to constructing hardware matching circuits on FPGAs are known. The most widely used of them are based on discrete comparators, hash-functions and finite automata. Each approach possesses its own pros and cons. None of them still became the leading one. In this paper, a method to combine several different approaches to enforce their advantages has been developed. An analytical technique to quickly advance estimate the resource costs of each matching scheme without need to compile FPGA project has been proposed. It allows to apply optimization procedures to near-optimally split the set of pattern between different approaches in acceptable time.


2009 ◽  
Vol 18 (1) ◽  
pp. 145-158
Author(s):  
Jiang Zhang ◽  
Keyword(s):  

1987 ◽  
Vol 10 (4) ◽  
pp. 415-435
Author(s):  
Kazimierz Wiśniewski
Keyword(s):  

1970 ◽  
Vol 1 (3) ◽  
pp. 10-10
Author(s):  
L. V. Matsevityy
Keyword(s):  

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