Sequential Synthesis of Distributed Controllers for Cascade Interconnected Systems
For engineers designing large-scale distributed control systems, this method reduces the need for global system knowledge and enables modular expansion.
The paper presents a distributed control design method for ensuring passivity in cascade-interconnected linear systems, where controllers are designed sequentially using only local subsystem dynamics and limited neighbor information. The approach allows compositional addition of new subsystems without redesigning existing controllers.
We consider the problem of designing distributed controllers to ensure passivity of a large-scale interconnection of linear subsystems connected in a cascade topology. The control design process needs to be carried out at the subsystem-level with no direct knowledge of the dynamics of other subsystems in the interconnection. We present a distributed approach to solve this problem, where subsystem-level controllers are locally designed in a sequence starting at one end of the cascade using only the dynamics of the particular subsystem, coupling with the immediately preceding subsystem and limited information from the preceding subsystem in the cascade to ensure passivity of the interconnected system up to that point. We demonstrate that this design framework also allows for new subsystems to be compositionally added to the interconnection without requiring redesign of the pre-existing controllers.