Ad Hoc Networks of Embedded Control Systems

University Of Notre Dame, Notre Dame IN

Investigators

Abstract

This project evaluates the extent to which ad hoc networks of embedded systems (NESTs) may be used to implement feedback control systems. Ad hoc NESTs are inexpensive and easy to deploy, but their ad hoc nature makes it impossible to realize feedback controllers in hard real-time. NEST feedback control systems, therefore, are soft real-time systems in which feedback measurements are delayed or dropped. Maintaining specified levels of overall closed loop performance in such a soft real-time environment is extremely challenging. This project will develop methods for assuring overall closed loop performance in NEST systems. This goal will be achieved by adopting a cross-disciplinary approach that integrates research efforts in control, real-time systems, computer systems, and communications. In particular, the project tackles this problem by 1) the dynamic re-routing of connections using a polynomial extension of minimum hop routing schemes, 2) the development of novel soft scheduling methods whose behavior can be directly related to closed loop controller performance, and 3) the dynamic re-allocation of link capacities through the use of combined channel coding and ARQ methods. The project's broader impacts will be expressed through an undergraduate level course that integrates control theory concepts with embedded system principles. Futher project impacts will be realized by coordinating this work with an existing DARPA contract that is developing middleware technologies for NEST-type systems.