Flexible performance design for the H∞ loop-shaping control based on the linear matrix inequality approach: Application to the coaxial rotor helicopter

This article introduces a new H∞ loop-shaping control to decrease the complexity of the appropriate selection of the required performance for a coaxial rotor helicopter with unpredicted or unknown unstructured uncertainties. Uncertainty models are normally assumed that some knowledge of type is known. And to model a particular uncertainty as a separate model is necessary in the high-performance design of specified applications. But to model each particular uncertainty will increase the complexity of performance design for the extremely complex plant. H∞ loop-shaping control provides a competitive and flexible choice to simultaneously represent a family of unpredicted and unconsidered unstructured uncertainty bounded by H∞ norm. Many researches have been conducted to consider some aspects of this method, for example, the nominal stability, robustness to uncertainty, and implementation issues. However, to decrease the complexity of the appropriate selection of the required performance was not considered ser...