An algorithm for hierarchical supervisory control

Abstract

A scheme for implementing hierarchical steady-state control objectives is presented in this paper. These objectives are implemented through a supervisory controller which provides setpoints to a standard regulatory control system. The setpoints are calculated through a sequence of optimization subproblems structured in such a way that objectives of any assigned priority are not compromised in favor of objectives of lower priority. The given procedure has a useful property that feasibility of the first subproblem guarantees feasibility of all the remaining subproblems. The supervisory control structure includes a feedback mechanism to compensate for unmodeled disturbances. The performance of the proposed scheme is demonstrated through example problems. The relatively small dimension of the optimization subproblems, the structure of the proposed scheme as a supervisory system independent of the regulatory control system and the simplicity of the calculation procedure should make this method attractive for industrial implementation.