A preliminary control design for the nonlinear benchmark problem

A nonlinear control problem has been posed by Bupp, Bernstein, and Coppola to provide a benchmark for evaluating various nonlinear control design techniques. In this paper, the state-dependent Riccati equation (SDRE) technique of Cloutier, D´Sousa and Mracek (1996) is utilized to produce a preliminary design for the benchmark problem. Analysis of the design shows that in the absence of disturbances and uncertainties, the SDRE nonlinear feedback solution compares very favorably to the optimal open-loop solution obtained via numerical optimization. It is also shown that the closed-loop system has stability robustness against parametric variations and low-frequency disturbances and attenuates middle-frequency disturbances