Output feedback controllers of suboptimality degree beta

A misconception in a recent paper by D.Z. Zheng (1989) about suboptimal feedback control is highlighted. A novel synthesis method for designing output feedback controllers of suboptimality degree beta is developed. These controllers yield a cost value equal to or less than a scalar multiple ( beta ) times the cost value obtained by optimal linear quadratic state feedback control. The output feedback control gains are explicit in terms of the standard Riccati equation when certain conditions are satisfied.<
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