Nonlinear control under polytopic input constraints with application to the attitude control problem

This work studies the control problem for nonlinear affine systems, subject to polytopic input constraints. A new paradigm is suggested as an alternative to the minnorm approach, to regulate the system while allowing it to operate within or at its saturation limits and minimizing a given pointwise performance index. The control input is obtained through the solution of a quadratic programming optimization problem. The applicability and efficacy of the method are illustrated on the input constrained attitude control problem.