Improvement of robustness and sensitivity reduction for multivariable nonminimum phase systems

The H/sub /spl infin// control theory is applied to control a nonminimum phase system, the Turboshaft GE T700 engine. Multi-input multi-output (MIMO) compensator is designed that minimizes the H/sub /spl infin// norm of the worst case disturbance input to the system. The simulations of both open loop and closed-loop systems are presented. Due to the existence of right-half zeros of the open loop plant, these unwanted modes are modeled as an uncertainty in the system, particularly for those which may result into tighter bounds of the performance that has been specified for this problem.