On decentralized estimation and control with application to freeway ramp metering

This paper presents an approach to the suboptimal design of time invariant, infinite time horizon, L-Q-G regulator in which decision making and state estimation are decentralized into "local" subsystems. For a prespecified information pattern (set of admissible intercommunications) the problem of finding a best linear control law and state estimator is converted to a parameter optimization which can be solved off line. A modified Davidon-Fletcher-Powell algorithm is used to obtain numerical solutions to the static optimization. A design is illustrated by means of a 12 state freeway corridor ramp metering problem; behavior of centralized and decentralized designs in a nonlinear macroscopic simulation of the freeway are provided.