Simplifying H∞ controller synthesis via classical feedback system structure

Substantial simplification of the H_∞ controller synthesis procedure in the case of open-loop stable plant and weight selection is shown to result from the use of a classical cascade controller feedback structure. In this case the solution to the second associated algebraic Riccati equation reduces identically to a null matrix 0_n, and this part of the controller computation can be dispensed with. The system structure allows effective tradeoff between significant closed-loop transfer functions