CONTROL OF SYMMETRICALLY INTERCONNECTED PLANTS

This paper is concerned with control of plants composed of n similar i nteracting subsystems. Such plants are common in practice and include paper machines, distribution networks, coating processes, and plants c onsisting of units operating in parallel. The transfer function matric es for these systems are block symmetric circulant. For H(infinity) an d H-2-optimal control, controller synthesis is simplified by consideri ng n/2 + 1 independent problems of dimension n times smaller than the original problem. For the case of H(infinity)-optimal control this als o yields 'super-optimality', where the H(infinity) criterion is optimi zed in n directions, and not only in the worst direction. If the offdi agonal blocks ('interactions') are identical the matrix is termed bloc k parallel, and controller synthesis involves only two independent sub -problems of the same dimension as the subsystems. This leads to a dra matic reduction in dimension for systems composed of many subsystems.