Biblio

In this paper, we propose a compositional scheme for the construction of abstractions for networks of control systems by using the interconnection matrix and joint dissipativity-type properties of subsystems and their abstractions. In the proposed framework, the abstraction, itself a control system (possibly with a lower dimension), can be used as a substitution of the original system in the controller design process. Moreover, we provide a procedure for constructing abstractions of a class of nonlinear control systems by using the bounds on the slope of system nonlinearities. We illustrate the proposed results on a network of linear control systems by constructing its abstraction in a compositional way without requiring any condition on the number or gains of the subsystems. We use the abstraction as a substitute to synthesize a controller enforcing a certain linear temporal logic specification. This example particularly elucidates the effectiveness of dissipativity-type compositional reasoning for large-scale systems.

This paper tackles the problem of constructing finite abstractions for formal controller synthesis with high dimensional systems. We develop a theory of abstraction for discrete time nonlinear systems that are equipped with variables acting as interfaces for other systems. Systems interact via an interconnection map which constrains the value of system interface variables. An abstraction of a high dimensional interconnected system is obtained by composing subsystem abstractions with an abstraction of the interconnection. System abstractions are modular in the sense that they can be rearranged, substituted, or reused in configurations that were unknown during the time of abstraction. Constructing the abstraction of the interconnection map can become computationally infeasible when there are many systems. We introduce intermediate variables which break the interconnection and the abstraction procedure apart into smaller problems. Examples showcase the abstraction of a 24-dimensional system through the composition of 24 individual systems, and the synthesis of a controller for a 6-dimensional system with a consensus objective.