Quantitative feedback design of uncertain multivariable control systems

An alternative QFT framework is proposed for the design of multiple-input multiple-output (MIMO) feedback systems with significant plant uncertainty. Sufficient conditions are first derived to assure the achievement of the given off-diagonal performance. Then the given performance bounds on each main channel are reallocated on a reasonable basis, such that not only is the main channel performance easily achieved, but also the trade-offs of performance bounds between the loops become transparent during the system synthesis.