Accurate Output Tracking Control for Nonminimum Phase Systems via An Iterative Redefinition-based Method with Aircraft Application

This paper provides an insight into the accurate output tracking control for non-minimum phase (NMP) systems. A novel iterative redefinition-based approach is proposed to overcome the inherent drawbacks of classic output-redefinition methods. Specifically, a feasible minimum phase (MP) output is first identified by the output redefinition. Then the desired output trajectory is iteratively redefined such that the state references for the new MP system could approximate those for the original NMP system within arbitrarily small errors. With the redefined reference signals, a controller in a "feedforward + feedback" configuration is employed to simultaneously achieve the accurate tracking of output trajectory and the stabilizing of internal dynamics. An application of this control framework to F-16 aircraft is presented, which is further verified by numerical simulations, showing significant performance improvement by the proposed output reference iterative redefinition algorithm.