A modular control design method for a flexible manufacturing cell including error handling

Abstract

This paper introduces a new modular control design method for a cell controller with integrated error handling. To make the complexity of the cell controller manageable, its control logic is separated into two parts: resource allocation control and operation control. To create the operation control not only quickly but correctly, modular operation blocks integrated with error handling are developed. An algorithm automatically generates the operation control. The operation control created by the proposed method is proved to have desired control behaviors. The method is applied to an example system.

Calculating Restart States for Systems Modeled by Operations Using Supervisory Control Theory

“…It is quite common in graph based restart methods to include additional error states and/or augmentations for recovery procedures, see for example [3,8,15,25,34]. Augmentations will most likely increase the state-space of the models.…”

“…Methods where the main work is done offline, such as [1,[9][10][11]13,[22][23][24][25], have an advantage compared to online methods, not only due to the need of less powerful hardware online. Beforehand calculation enables different restart alternatives to be analyzed already when the production in the manufacturing system is planned, such that undesirable situations can be resolved if possible.…”

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

“…Brandl [3]) or distributed control systems like the MVCDA (Model-ViewController-Diagnostic-Adapter) design patterns proposed by Christensen [4]. Lee and Tilbury [5] developed a modular controller design methodology for manufacturing systems, which also considers integrated fault handling on manufacturing cell level. Furthermore, Ferrarini et al [6] proposed a methodology for fault isolation in control systems based on programmable logic controllers (PLCs).…”

Software Framework for Advanced Error Troubleshooting in Flexible Manufacturing System

“…Over the last decades, various approaches have been proposed for monitoring flexible manufacturing systems. Lee and Tilbury [1] introduce an error handling method in the cell level controller software. They separate the control logic into two parts: resource allocation control and operation control.…”