Design patterns for separating fault handling from control code in discrete manufacturing systems

Abstract

The objective of this paper is to propose a methodology for strictly separating fault detection and fault handling methods from control code in discrete manufacturing systems. In order to enable the separation, two different design patterns are elaborated. Based on an analysis of typical faults in manufacturing systems, a library of reusable function blocks for fault detection, handling, and also fault recovery is developed. These function blocks are implemented according to the international standard IEC 61499 and are applied within the design patterns. The design patterns are evaluated with the sequential control of an injection molding machine. It is shown, that the design patterns simplify the engineering and the separation of the fault detection and fault handling from control code significantly, since they provide clear design rules. Applying the proposed design patterns reduces the complexity of industrial control applications drastically. Furthermore, the function block library provides reusable and proven fault detection and fault handling methods.

A Design Pattern for Monitoring Adapter Connections in IEC 61499

“…Ref. [10] presented an approach for extracting common error handling code by introducing a design pattern which allowed to intercept adapter connections feedback free. To overcome the limitations of the previous monitoring approaches we propose to expand the adapter interception concept from [10] and to explicitly add the monitor components as part of the IEC 61499 application.…”

“…Based on that [8] presents a remote monitoring infrastructure, while [9] focuses on specification formalisms for monitoring and an integration into the Eclipse environment. A so-called sniffer pattern is introduced in [10]. An investigation on the correctness of run-time monitors themselves has been conducted in [11].…”

Approaches to mastering variability in software-intensive Cyber-Physical Production Systems

“…Komponenten unterstützen, die für die Beherrschung der Variabilität erforderlich sind [32,51]. Dies bedeutet auch Refactoring Methoden zur Umwandlung der bestehenden Modelle in modulare Architekturen als Grundlage für die Variabilitätsmodellierung und -analyse zu entwickeln [50,53].…”

Achieving resilience for cyber-physical systems with 4DIAC IEC 61499 through parametric contracts

“…Moreover, to compartmentalize information within the system, every time the CM performs a reconfiguration, it has to consult other managers to obtain information about services, service implementations, and the application itself before reconfiguration.Increasingly complex functional and safety requirements of CPSs contribute to complicated and hard to understand control applications. Typical manufacturing applications have 17% of control code for normal operations, and the remaining 83% accounts for fault handling code on average[31,32]. With more components, there are large amounts of code which can be difficult to understand while maintaining the original codebase.…”

“…With more components, there are large amounts of code which can be difficult to understand while maintaining the original codebase. This problem is exacerbated when application codes are directly linked with fault handling codes[32]. Thus, there is a need for an approach which decouples fault handling techniques from application code.Therefore, a resilience management framework which is scalable, quick to detect and fast to recover from faults, and separates application code from fault handling code is immensely beneficial.In order to overcome the challenges a future smart factory would face, we propose our HCRF[14].…”