Papers by Sławomir Samolej
Consequences of the Form of Restrictions in Coloured Petri Net Models for Behaviour of Arrival Stream Generator Used in Performance Evaluation
Computer Networks
Regular graph-based free route flight planning approach
Aircraft Engineering and Aerospace Technology
Purpose The purpose of this study is to provide an alternative graph-based airspace model for mor... more Purpose The purpose of this study is to provide an alternative graph-based airspace model for more effective free-route flight planning. Design/methodology/approach Based on graph theory and available data sets describing airspace, as well as weather phenomena, a new FRA model is proposed. The model is applied for near to optimal flight route finding. The software tool developed during the study and complexity analysis proved the applicability and timed effectivity of the flight planning approach. Findings The sparse bidirectional graph with edges connecting only (geographically) closest neighbours can naturally model local airspace and weather phenomena. It can be naturally applied to effective near to optimal flight route planning. Research limitations/implications Practical results were acquired for one country airspace model. Practical implications More efficient and applicable flight planning methodology was introduced. Social implications Aircraft following the new routes will...
A new software tool for web-server systems development is presented. The tool consist of a set of... more A new software tool for web-server systems development is presented. The tool consist of a set of predefined Hierarchical Timed Coloured Petri Net (HTCPN) structures - patterns. The pat- terns make it possible to naturally construct typical and experimental server-systems structures. The preliminary patterns are executable queueing systems. A simulation based methodology of web-server model analysis and validation has been proposed. The paper focuses on presenting the construction of the software tool and its application for selected cluster-based web-servers load balancing strategies evaluation.
The paper reports Rzeszow University of Technology Research Team contributions to the European Co... more The paper reports Rzeszow University of Technology Research Team contributions to the European Community SCARLETT project. The main objective of the research team was to prepare an avionic pitch control hard real-time application following ARINC 653 and ARINC 664 specifications. VxWorks 653 and PikeOS real-time operating systems are the application platforms. The paper mentions a general SCARLETT project objectives and the ARINC 653 specification. The main part of the paper includes a report of the application's development and its evaluation. ARINC 653, VxWorks 653, PikeOS, hard real-time systems, control systems, avionics, Integrated Modular Avionics I. INTRODUCTION Modern airliner's computer systems include a vide set of hard real-time applications [7]. Typical avionic components such as cruise speed, flight level or pitch angle control systems can be good examples of them. It is worth to notice that the avionic hard real-time systems have to usually both execute control ...
MATEC Web of Conferences
This article describes some of tasks carried out as a part of an international project ERA (Enhan... more This article describes some of tasks carried out as a part of an international project ERA (Enhanced RPAS Automation, RPAS – Remotely Piloted Aircraft Systems). The works were focused on a control system for an optionally piloted aircraft MP-02 Czajka, especially on adapting the control system for piloting the aircraft in take-off and landing phases. The entry point was the control system built on using PID controllers in the aircraft. The quality of the control system was insufficient; especially for steering in critical flight states such as take-off and landing. The aim was to improve and fine-tune it to the object, which would allow to shorten time constants of the system, reduce overshoots and errors. It was decided to leave a general structure of a control algorithm based on PID controllers, however, it was extended with additional elements, among others blocks of additional damping, “fit forward” blocks and others. The article describes control laws and their modification as ...
Time Extensions of Petri Nets for Modelling and Verification of Hard Real-Time Systems
The main aim ofthe paper is a presentation of time extensions of Petri nets appropriate for model... more The main aim ofthe paper is a presentation of time extensions of Petri nets appropriate for modelling and analysis of hard real-time systems. It is assumed, that the extensions must provide a model of time flow an ability to force a transition to fire within a stated timing constraint (the so-called the strong firing rule), and timing constraints represented by intervals. The presented survey includes extensions of classical Place/Transition Petri nets, as well as the ones applied to high-level Petri nets. An expressiveness of each time extension is illustrated using simple hard real-time system. The paper includes also a brief description of analysis and veryication methods related to the extensions, and a survey of software tools supporting modelling and analysis ofthe considered Petri nets.
The paper reports Rzeszow University of Technology Research Team contributions to the European Co... more The paper reports Rzeszow University of Technology Research Team contributions to the European Community SCARLETT project. The main objective of the research team was to prepare an avionic pitch control hard real-time application following ARINC 653 and ARINC 664 specifications. VxWorks 653 and PikeOS real-time operating systems are the application platforms. The paper mentions a general SCARLETT project objectives and the ARINC 653 specification. The main part of the paper includes a report of the application's development and its evaluation. ARINC 653, VxWorks 653, PikeOS, hard real-time systems, control systems, avionics, Integrated Modular Avionics I. INTRODUCTION Modern airliner's computer systems include a vide set of hard real-time applications [7]. Typical avionic components such as cruise speed, flight level or pitch angle control systems can be good examples of them. It is worth to notice that the avionic hard real-time systems have to usually both execute control ...
Using Computer Graphics, Vision and Gesture Recognition Tools for Building Interactive Systems Supporting Therapy of Children
Advances in Intelligent and Soft Computing, 2012
ABSTRACT The paper presents a prototype of a system which can be used as a therapeutic and educat... more ABSTRACT The paper presents a prototype of a system which can be used as a therapeutic and educational tool for children with developmental problems. Natural body movements and gestures are used in the system to interact with virtual objects displayed on the screen. Nowadays such systems can be built with the use of widely available free software tools for both graphical and vision applications. Such tools are also shortly presented in the paper.
AIAA Guidance, Navigation, and Control Conference, 2011
The SCAlable & ReconfigurabLe Electronics plaTforms and Tools project (SCARLETT) was started by E... more The SCAlable & ReconfigurabLe Electronics plaTforms and Tools project (SCARLETT) was started by European Commission to develop the concept of IMA 2G Avionics. The paper mentions the main objectives of the SCARLET project and presents a sample time-critical application developed for it. The time-critical application is an ARINC 653 based and is a part of a distributed control system working in AFDX network environment. Its task is to control an elevator's actuator of a typical airliner. The paper presents the structure of the application, its timing schedule, and dedicated control algorithms and error detection mechanism built-in it. Selected application tests conclude the paper. 2 American Institute of Aeronautics and Astronautics Support for the full range of avionics function. The SCARLETT project Błąd! Nie można odnaleźć źródła odwołania. is an European enterprise joining 39 companies from 16 countries including large industrial companies, public research centres, industrial research centres, universities, small and medium enterprises. One of the project partners is Rzeszow University of Technology (RUT) Research Team (RUTRT). This paper presents the current RUTRT's contribution to the SCARLETT project. The RUTRT takes part in a time critical application development and testing SCARLETT research path. Its task is to prepare a specific hard real-time application that would be executed at several SCARLETT hardware modules. The application should be a part of a control system and make it possible to evaluate whether DME units can be effectively used as hard real-time applications platforms. The preliminary research results of RUTRT were published in 7. The next sections of the paper are organised as follows. Firstly the main SCARLETT DME units will be shortly introduced. Secondly a Pitch Control Application (an illustrative example of the time-critical avionic control system) developed by the RUTRT will be presented. The section will include decryptions of: system specification, application implementation and built-in self testing procedures. The final part of the paper will include our future research plans.
The integration of a prototype pitch control application with IMA2G devices
Automatyka/Automatics, 2013
Lecture Notes in Computer Science, 2012
An extension of HTCPNs-based software tool for Internet systems modelling and evaluation has been... more An extension of HTCPNs-based software tool for Internet systems modelling and evaluation has been proposed in the paper. After the extension the tool provides new possibilities for modelling and analysis of dynamic cluster reconfiguration algorithm. Some implementation details of the algorithm has been presented. The algorithm has been preliminary assessed by simulation.
e-Informatica Software Engineering Journal, 2012
This paper reports successive steps of a real-time avionic pitch control application creation. Th... more This paper reports successive steps of a real-time avionic pitch control application creation. The application structure follows a new real-time systems development profile published in ARINC specification 653. The paper mentions some main ARINC specification 653 features and shows the subsequent application creation levels: control system units distribution, timing requirements definition, application implementation and tests. It describes the author's experience gained during an avionic hard real-time system development and focuses on real-time software engineering details of the application creation.
Problemy implementacji systemu sterowania lotem na platformę systemu operacyjnego czasu rzeczywistego VxWorks
Scientific Letters of Rzeszow University of Technology - Mechanics, 2013
Computer vision and graphics based system for interaction with mentally and physically disabled children
3rd International Conference on Human System Interaction, 2010
The paper presents a prototype of a system which can be used as a therapeutic and educational too... more The paper presents a prototype of a system which can be used as a therapeutic and educational tool for children with developmental problems. Natural body movements and gestures are used in the system to interact with virtual objects displayed on the screen. Nowadays such systems can be easily built with the use of widely available free software tools for both
Distributed internet systems modeling using TCPNs
Proceedings of the International Multiconference on Computer Science and Information Technology, IMCSIT 2008, 2008
ABSTRACT This paper presents a timed coloured Petri nets based programming tool that supports mod... more ABSTRACT This paper presents a timed coloured Petri nets based programming tool that supports modeling and performance analysis of distributed World Wide Web environments. A distributed Internet system model, initially described in compliance with queueing theory (QT) rules, is mapped onto the Timed coloured petri net (TCPN) structure by means of queueing system templates. Then, it is executed and analyzed using design/CPN toolset. The proposed distributed Internet systems modeling and design methodology has been applied for evaluation of several system architectures under different external loads.
TCPN-Based Tool for Timing Constraints Modelling and Validation
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 2011
A new software tool for web-server clusters development is presented. The tool consist of a set o... more A new software tool for web-server clusters development is presented. The tool consist of a set of predefined Hierarchical Timed Coloured Petri Net (HTCPN) structures-patterns. The patterns make it possible to naturally construct typical and experimental server-cluster structures. The preliminary patterns are executable queueing systems. A simulation based methodology of web-server model analysis and validation has been proposed. The paper focuses on presenting the construction of the software tool and the guidelines for applying it in cluster-based web-server development.
This paper presents a Timed Coloured Petri Nets based programming tool that supports modeling and... more This paper presents a Timed Coloured Petri Nets based programming tool that supports modeling and performance analysis of distributed World Wide Web environments. A distributed Internet system model, initially described in compliance with Queueing Theory (QT) rules, is mapped onto the Timed Coloured Petri Net (TCPN) structure by means of queueing system templates. Then, it is executed and analyzed. The proposed distributed Internet systems modeling and design methodology has been applied for evaluation of several system architectures under different external loads. Povzetek: Predstavljeno je orodje na osnovi Petri mrež za modeliranje spletnih okolij.
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Papers by Sławomir Samolej