Nonautonomous elementary net systems and their application to programmable logic control

In this paper, a novel approach to Petri net modeling of programmable logic controller (PLC) programs is presented. The modeling approach is a simple extension of elementary net systems, and a graphical design tool that supports the use of this modeling approach is provided. A key characteristic of the model is that the binary sensory inputs and binary actuation outputs of the PLC are explicitly represented. This leads to the following two improvements: outputs are unambiguous, and interaction patterns are more clearly represented in the graphical form. The use of this modeling approach produces programs that are simple, lightweight, and portable. The approach is demonstrated by applying it to the development of a control module for a MonTech Positioning Station. © 2008 IEEE.

Inserting innovations in-service

Military platforms have exceptionally long lifecycles and given the state of defense budgets there is a significant trend in sustaining the operational capability of legacy platforms for much greater periods than originally designed. In the context of through-life management, one of the key questions is how to manage the flow of technology for platform modernization during the in-service phase of the lifecycle? Inserting technological innovations in-service is achieved through technology insertion processes. Technology insertion is the pre-eminent activity for both maintaining and enhancing the functional capability of a platform especially given the likely changes in future military operations, the pace of change in technology and with the increasing focus on lifecycle cost reduction. This chapter provides an introduction to technology insertion together with an overview of the key issues that practitioners are faced with. As an aid to planning technology insertion projects, a decision-support framework is presented. © 2010 Springer-Verlag Berlin Heidelberg.