Mixed H¥- Describing Function Approach to Design of Nonlinear Control Systems

A new single range controller design approach for use with nonlinear systems of a general nature is developed. The approach is based on one describing function model of the nonlinear process coupled with the application of the ∞ H control theory. The approach is applicable to nonlinear systems of a general nature without any restrictions on nonlinearity type, number of nonlinear terms, nonlinearity arrangement, or system order. The approach is applied to a nonlinear system of the sort encountered in aerospace, and the results are compared with those obtained by one other alternative method that was previously reported in the open literature.