PERFECT EXPLICIT MODEL-FOLLOWING CONTROL SOLUTION TO IMPERFECT MODEL-FOLLOWING CONTROL-PROBLEMS

For cases in which perfect model-following is not possible for a particular desired model, a class of candidate models is defined that can be followed perfectly by the given plant. A candidate model that most closely matches the dynamics of the desired model is then determined through constrained parameter optimization. The result is perfect model-following of a model that has an eigenstructure which resembles that of the desired model. In the development of this method, a new variation on perfect model-following control law development is shown. This method explicitly displays the feed-forward and feedback gains that determine the system error dynamics, which may be artibrarily selected by conventional pole placement methods if the plant is completely controllable. The method is applied to a problem involving the linearized lateral-directional equations of motion of the B-26 airplane. The results show that a candidate model can be found that has virtually the same dynamic behavior as the desired model, and that it can be followed perfectly by the original plant with arbitrarily assigned error dynamics.