scholarly journals Simulation and Formal Verification for Improving Safety of PLC Programs

2016 ◽  
Vol 3 (1-2.) ◽  
Author(s):  
Joel Galvão ◽  
José Machado

The use of analysis techniques for improving quality of software for industrial controllers is widely used. Mainly Simulation and Formal Verification can be used as complementary techniques improving dependability of mechatronic systems behavior. In this paper there are used Simulation and Formal Verification for guaranteeing safe software for Programmable Logic Controllers, mainly related with using Function blocks of IEC 61131-3 standard. For studying, simulating and verifying behavior of those blocks are used timed automata, as modeling formalism, and UPPAAL, as tool for simulation and Formal Verification purposes.

Author(s):  
E. Miron ◽  
J. P. Mendonca ◽  
J. Machado ◽  
D. Olaru ◽  
G. Prisacaru

The design of mechatronic systems is a multidisciplinary task that involves skills from mechanic, electronic and informatics areas. Recently, the expertise from such different fields is able to communicate and exchange the necessary contribution to successful design solutions, through a myriad of internet tools available. The introduction of internet of services on the design of mechatronic systems, mainly when teams, with different skills, operate in different geographic places, has contributed to flawlessly integrate better and interoperable final solutions. The design of mechatronic systems without errors — that operate without failures — is an important contribution to such goal. Safe behavior of mechatronic systems is crucial, mainly, in what concerns human safety. The correct behavior of those systems can be improved by the development of safe software for their controllers using some analysis techniques. Among them, Formal Verification (FV) is able to guarantee the best results. One of the main gaps using this technique is the difficulty of obtaining adequate plant models, in a systematic way, because this task is, usually, related with high level of expertise of designers and, in industry, this fact causes some difficulties for using those methods and tools. The work presented in this paper is a part of a larger project developed in the context of Software as a Service (SaaS) platform. It is intended to develop a systematized approach in order to obtain meaningful plant models out of existing CAD data, from Autodesk Inventor (or CATIA), and translate those models to formatted files according to input data of the UPPAAL model-checker (because it allows dealing with time variable). The main idea is to obtain, systematically, plant models for Formal Verification purposes, considering that nowadays companies with different CAD systems are using increasingly often STEP-File format. A solution for this specific problem is explored and presented in this paper.


2020 ◽  
Vol 6 (2) ◽  
pp. 169
Author(s):  
Philip Nababan ◽  
Efendi Napitupulu ◽  
R Mursid

Abstrak: Penelitian ini bertujuan untuk: (1) Mengetahui tanggapan siswa terhadap kualitas media pembelajaran interaktif pada pembelajaran Teknik Pemesinan Bubut. (2) Mengetahui keefektifan media pembelajaran interaktif pada pembelajaran Teknik Pemesinan Bubut pada siswa program keahlian Teknik Pemesinan. Jenis penelitian ini adalah penelitian pengembangan. Data tentang kualitas produk pengembangan ini dikumpulkan dengan angket dan dianalisis dengan teknik analisis deskriptif kualiatatif. Hasil penelitian menunjukkan bahwa; (1) uji ahli materi pelajaran Teknik Pemesinan Bubut berada pada kualifikasi sangat baik (88,92%), (2) uji ahli desain pembelajaran berada pada kualifikasi sangat baik (85,21%), (3) uji ahli rekayasa perangkat lunak berada pada kualifikasi sangat baik (84,03%), (4) uji coba perorangan berada pada kualifikasi sangat baik (88,75%), (5) uji coba kelompok kecil berada pada kualifikasi sangat baik (91,35%) dan (5) uji coba lapangan berada pada kualifikasi sangat baik (88,31%). Hasil pengujian hipotesis membuktikan bahwa terdapat perbedaan antara hasil belajar siswa yang menggunakan media pembelajaran interaktif  dengan hasil belajar siswa yang menggunakan buku teks. Hal ini ditunjukkan dengan hasil pengolahan data diperoleh  thitung sebesar 4,68 dan ttabel sebesar 1,67 pada taraf kepercayaan 95 persen. Maka diperoleh bahwa thitung> ttabel. Disimpulkan bahwa  hasil belajar siswa yang menggunakan media pembelajaran interaktif dengan efektifitas sebesar 72,77 %. lebih tinggi dari hasil belajar siswa yang diajar dengan pembelajaran menggunakan buku teks dengan efektifitas sebesar 62,13%. Kata Kunci: media pembelajaran interaktif, teknik pemesinan bubut Abstract: This study aims to: (1) Determine student responses to the quality of interactive learning media on learning Lathe Machining Techniques. (2) Knowing the effectiveness of interactive learning media on learning of Machining Lathe in students of Machining Engineering expertise program. This type of research is development research. Data about the quality of this development product was collected by a questionnaire and analyzed by qualitative descriptive analysis techniques. The results showed that; (1) Lathe machining engineering subject matter expert test is in very good qualification (88.92%), (2) learning design expert test is in very good qualification (85.21%), (3) software engineering expert test is in in very good qualifications (84.03%), (4) individual trials were in very good qualifications (88.75%), (5) small group trials were in very good qualifications (91.35%) and (5 ) field trials are in very good qualifications (88.31%). Hypothesis testing results prove that there are differences between student learning outcomes using interactive learning media with student learning outcomes using textbooks. This is indicated by the results of data processing obtained by tcount of 4.68 and ttable of 1.67 at a confidence level of 95 percent. Then it is obtained that tcount> ttable. It was concluded that student learning outcomes using interactive learning media with an effectiveness of 72.77%. higher than student learning outcomes taught by learning to use textbooks with an effectiveness of 62.13%. Keywords: interactive learning media, lathe machining techniques


Author(s):  
Sri Winarsih

This study aims to determine the appropriate steps in carrying out academic supervision so as to be able to improve the pedagogical competence of teachers, especially in the learning process which in turn will affect the improvement of the quality of education.The study was conducted in two cycles. Each cycle has different planning, implementation, observation and reflection. Research subjects of the principal and teacher. The school principal with his academic supervision measures, while the Kunto Darussalam Elementary School 017 teacher as an object as well as the subject in providing academic supervision treatment. Data collection techniques through class supervision with stages of supervising teachers in the learning process and observation of classroom learning, to record important events related to research, especially at the time of the processlearning takes place.Data analysis techniques that guide data processing using a percentage (%) of achievement with 100 constants. And to see the interpertation using score interpertation criteria to strengthen the interpretation in conclusions as follows: 80% - 100% (Very Good), 66% - 79 % (Good), 56% - 65% (Enough), and 40% - 55% (Less).The results showed that the ability of teachers in the implementation of the learning process experienced an increase in the percentage at each stage, from the first cycle reached an average of 63% (sufficient) and in the second cycle reached an average of 68% (good). There is an increase in teacher's ability by 5% from cycle I. In detail there is a significant increase in the initial condition of the school when compared to the final condition in the second cycle. The accuracy of teachers entering the class increased by 48%, the use of learning media increased by 32%, varied methods increased by 31%, and learning strategies increased by 36%.


2021 ◽  
Vol 54 (7) ◽  
pp. 1-37
Author(s):  
Jihyeok Park ◽  
Hongki Lee ◽  
Sukyoung Ryu

Understanding program behaviors is important to verify program properties or to optimize programs. Static analysis is a widely used technique to approximate program behaviors via abstract interpretation. To evaluate the quality of static analysis, researchers have used three metrics: performance, precision, and soundness. The static analysis quality depends on the analysis techniques used, but the best combination of such techniques may be different for different programs. To find the best combination of analysis techniques for specific programs, recent work has proposed parametric static analysis . It considers static analysis as black-box parameterized by analysis parameters , which are techniques that may be configured without analysis details. We formally define the parametric static analysis, and we survey analysis parameters and their parameter selection in the literature. We also discuss open challenges and future directions of the parametric static analysis.


2016 ◽  
Vol 65 (1) ◽  
pp. 107-125 ◽  
Author(s):  
Radu Calinescu ◽  
Carlo Ghezzi ◽  
Kenneth Johnson ◽  
Mauro Pezze ◽  
Yasmin Rafiq ◽  
...  

2021 ◽  
Vol 20 (5s) ◽  
pp. 1-26
Author(s):  
Jinghao Sun ◽  
Nan Guan ◽  
Rongxiao Shi ◽  
Guozhen Tan ◽  
Wang Yi

Research on modeling and analysis of real-time computing systems has been done in two areas, model checking and real-time scheduling theory. In model checking, an expressive modeling formalism such as timed automata (TA) is used to model complex systems, but the analysis is typically very expensive due to state-space explosion. In real-time scheduling theory, the analysis techniques are highly efficient, but the models are often restrictive. In this paper, we aim to exploit the possibility of applying efficient analysis techniques rooted in real-time scheduling theory to analysis of real-time task systems modeled by timed automata with tasks (TAT). More specifically, we develop efficient techniques to analyze the feasibility of TAT-based task models (i.e., whether all tasks can meet their deadlines on single-processor) using demand bound functions (DBF), a widely used workload abstraction in real-time scheduling theory. Our proposed analysis method has a pseudo-polynomial time complexity if the number of clocks used to model each task is bounded by a constant, which is much lower than the exponential complexity of the traditional model-checking based analysis approach (also assuming the number of clocks is bounded by a constant). We apply dynamic programming techniques to implement the DBF-based analysis framework, and propose state space pruning techniques to accelerate the analysis process. Experimental results show that our DBF-based method can analyze a TAT system with 50 tasks within a few minutes, which significantly outperforms the state-of-the-art TAT-based schedulability analysis tool TIMES.


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