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1

Quality of Automation

Halang W. A.

Pomiary Automatyka Robotyka

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2012

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R. 16, nr 2

42-47

EN

As manufacturing and logistics processes have a significant impact on the quality of products and services, the quality of the automation involved should be considered as well. To this end, a list of quality criteria for automating systems is proposed, consisting of qualitative exclusive, qualitative gradual and of quantitative criteria. It is shown that qualitative characteristics are much more important than quantitative ones. Provided that they fulfill the exclusive criteria, automating systems may then be compared on the basis of the gradual and quantitative ones. Since quality of automation also depends on the quality of the corresponding engineering processes, some criteria are compiled to evaluate the quality of automating, and critical points of technological regress in the design and development processes of automation systems are identified. Finally, the quality of automation as such is addressed and several requirements for it mentioned. It is indicated that automation may not always be useful, and that it can turn out harmful to society.

PL

W artykule zaproponowano kryteria jakościowe (wyłączające i stopniowalne) oraz ilościowe oceny jakości systemów automatyki. Pokazano, że charakterystyki jakościowe są dużo ważniejsze od ilościowych. Wykazano, że po spełnieniu szczególnych warunków systemy automatyki mogą być porównywane ze sobą na bazie kryteriów stopniowalnych i jakościowych. Opracowano kryteria ewaluacji jakości automatyzacji oraz zidentyfikowano punkty krytyczne regresu technologicznego w projektowaniu i rozwijaniu systemów automatyki. Omówiono szereg wymagań odnośnie jakości automatyzacji per se. Wskazano także, że automatyzacja nie zawsze jest użyteczna, a wręcz może być społecznie szkodliwa.

2

Design of microprogrammed controllers to be implemented in FPGAs

Wiśniewski R., Barkalov A., Titarenko L., Halang W. A.

International Journal of Applied Mathematics and Computer Science

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2011

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Vol. 21, no 2

401-412

EN

In the article we propose a new design method for microprogrammed controllers. The traditional structure is improved by modifying internal modules and connections. Such a solution allows reducing the total number of logic elements needed for implementation in programmable structures, especially Field Programmable Gate Arrays (FPGAs). Detailed results of experiments show that on the average the application of the proposed methods yields up to 30% savings as far as the destination device is considered.

3

A programmable inference controller meeting highest safety requirements

Vogrin P., Halang W. A.

Journal of Automation Mobile Robotics and Intelligent Systems

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2010

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Vol. 4, No. 1

8-19

EN

A programmable controller suited for automation applications of highest safety criticality is presented. Its features are input conditioning by low-resolution analogue-to-digital converters, inference by look-up in rule set tables, strictly periodic and jitter-free operation, high speed and simplicity of design. A fail-safe supervisor immediately initiates an emergency shut-down in case of a malfunction. The software in form of rule base tables can easily be verified by inspection. This device is used to implement control algorithms working with set-point preprocessors, which calculate internal set-point graphs of controlled variables in such a way that very high controller gains are attainable and, thus, stability is increased. The performance of these „SPP” controllers is closer to the „best physically possible”, and much more predictable than the one of conventional control structures. The otherwise conficting design objectives stability, safety, high speed, small energy consumption, or steady and harmonic temporal controller output values can nearly all be achieved.

4

Projektowanie sterowników mikroprogramowanych z wykorzystaniem bloków pamięci układów programowalnych

Wiśniewski R., Barkalov A. A., Halang W. A.

Pomiary Automatyka Kontrola

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2009

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R. 55, nr 8

569-571

PL

W artykule zaprezentowana zostanie nowa metoda projektowania sterowników mikroprogramowanych. W proponowanym rozwiązaniu zarówno moduł pamięci, jak i część adresująca sterownika realizowane są z wykorzystaniem dedykowanych bloków pamięci układów programowalnych. Dzięki temu układ sterujący może zostać w łatwy sposób zweryfikowany pod kątem bezpieczeństwa. Ponadto zredukowana zostaje liczba wykorzystanych elementów logicznych, które są niezbędne do implementacji układu sterującego w matrycach programowalnych. Trzecią istotną korzyścią proponowanej metody jest możliwość zastosowania częściowej rekonfiguracji zarówno części zarządzającej jak i modułu pamięci sterownika. Idea metody zostanie zilustrowana przykładem. Pokazane zostaną wszystkie kroki, które są niezbędne do realizacji układu z wykorzystaniem proponowanej metody.

EN

A compositional microprogram control unit (also called a microprogrammed controller) is a multi-level device whose control unit consists of two main units. The first one is responsible for addressing microinstructions that are kept in a control memory. It is a simple finite-state machine. The role of the second unit is to hold and generate adequate microinstructions. Such a solution permits to minimize the number of logic elements required to implement the control unit. Therefore, wider areas of the target device can be accessed by other modules of the designed system. The control memory can be implemented using either logic elements or dedicated memory blocks of a chip. In this paper a new design method of microprogrammed controllers is proposed. Its idea is to implement the addressing part of microprogrammed controllers with memories. This kind of solutions has three main advantages. First of all, such designs can easily be verified thanks to the regular structure of memories, which fosters the inherent safety of entire control units. Moreover, in such a case the design is implemented with a System-on-Programmable-Chip (SoPC), the additional resources available there in form of programmable devices may be used. It is possible to implement the addressing part of a control unit with dedicated memory blocks of an SoPC, which results in a reduction of logic elements (especially look-up tables) required. Finally, the concept allows application of partial reconfiguration of an SoPC. Thus, the functionality of the whole controller can be easily and quickly modified. The proposed method is illustrated by an example. All steps required in order to design and prototype microprogrammed controllers based on the presented concept are shown in detail.

5

Incorporating Fault Tolerance into Component-based Architectures for Embedded Systems

Lu S., Halang W. A.

Journal of Automation Mobile Robotics and Intelligent Systems

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2009

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Vol. 3, No. 1

46-51

EN

Component-based software architecture is presented to support the process of designing and developing fault-tolerant computerised control systems. To this end, we combine an idealised fault-tolerant component, the C2 architecture style and protective wrappers, and embed fault tolerance techniques into component definitions. The resulting architecture is described by normal- and abnormal-activity components aiming to support a wide range of fault tolerance features. Use of this architecture enables to reason about system dependability already from the earliest development stages on, and to customise fault tolerance strategies according to application characteristics.