Decision making by using tree-like structures on industrial controllers

The implementation of a decision making technique on industrial controllers is a constrained task since the controllers are programmed with languages standardized by the IEC 61131-3, which are meant for controlling processes, limiting the possibilities that traditional high level programming languages offer. So far most of the implementations of decision making techniques are done by executing the code on an external computer which is interfaced to an industrial controller. Decision tree structures can be used as a visual tool for designers to model the decision making of an industrial controller intuitively. Different situations can be modeled so that the controller knows how to act for each of them. Tree-like structures can be visualized as nested Boolean evaluations which can be easily converted to any of the IEC 61131-3 languages. Therefore the decision making logic can be executed directly on the industrial controller. The proof of concept is tested on a SCARA robot that has to execute different sequence of movements depending on the components state within a flexible manufacturing cell.