A design method for plug-and-play control of large-scale systems with a varying number of subsystems

This paper presents an online procedure to design decentralised controllers for a large-scale system when subsystems are added or removed. As the dynamics of all subsystems depend upon each other through the physical couplings, the main challenge of the controller design is to ensure global I/O stability and a required I/O performance of the overall large-scale system. For this purpose, plug-and-play control is devoted to the following two issues: first, the set-up of a model to describe the global system behaviour by limited model information only. Second, the design of the control station of the added subsystem based on this model with respect to local design requirements in order to guarantee the satisfaction of global system specifications. Furthermore, it is allowed to adjust neighbouring control stations to ensure a good overall system performance neighbouring subsystems are allowed to adjust their control stations. As a consequence, a new subsystem can be “plugged-in” and automatically “plays” together with the existing subsystems to guarantee a global performance. The overall procedure is experimentally evaluated by application to a thermo-fluid plant.