Optimal model matching with disturbance rejection for the non-minimum phase plants

The design problem of optimal (or perfect) model matching control system with minimal weighted sensitivity to disturbance is considered in this paper. A system is said to achieve optimal (or perfect) model matching control if the system is internally stable and the H_∞-norm of the difference between its closed-loop transfer function and that of the reference plant is minimized (or zero). So, the design of an optimal model matching control system leads to an H_∞-optimization problem. A controller achieving optimal model matching control still has free design parameters, which can be utilized to reduce the effect of external disturbances. The disturbance rejection problem is transferred into another weighted optimization problem with constraints which come from the optimal model matching design. A new method is proposed to solve the resulting two coupled H_∞-optimization problems by interpolation method