A multi-controller with bumpless transfer architecture for industrial switched-mode processes

Switched mode systems are defined as those represented by a finite set of linear subsystems and a set of logic rules orchestrating the switching among them. A set of dynamic subsystems together with a logical system that orchestrates the switching among them could be used in order to describe it. An alternative to control them is a supervisory multi-mode controller architecture that allows to meeting multiple control objectives. But switching can consequently derived in bumps or undesirable transient responses. This type of problem is commonly encountered in several industrial application fields, where the Programmable Logic Controller (PLCs) is the most used technology. This paper describes a methodology for the design and the implementation of Bump less Transfer (BT) mechanisms within multi-rate control architecture for switched mode systems, to be implemented in PLC following the IEC 61131-3 standard. The BT strategy is based on to make controllers which are candidate to switch track to active controllers. By detecting the system state and the feasible next states, the supervisor decides the way in which the different controllers of the architecture execute. The steps to design the complete architecture are presented and experimental results that validate the architecture are shown.