Nicely Nonlinear LQ-based Control

Nicely Nonlinear LQ-based Control is a novel three-stages technique to easily get a sub-optimal solution to the infinite horizon standard regulation problem for nonlinear systems. It approximates the plant with its second order-truncated Taylor series (stage I), operates a feedback linearization on the resulting linear-quadratic model (stage II) and, then, for the linearized system, solves a classical infinite horizon LQ optimal tracking problem (stage III). As a preliminary step, it is proved in the following that such a control scheme guarantees local exponential stability for class C2 affine systems. Nicely Nonlinear LQ-based Control is then applied in simulation to regulate a DC/AC converter on a fixed reference set-point and its performances are compared with the classical LQ strategy.