Input saturation and global stabilization by output feedback for affine systems

For multi-input multi-output nonlinear systems whose free dynamics are Lyapunov stable, we show how the problem of global stabilization via dynamic output feedback can be solved by using the technique of input saturation. The power of this technique is also illustrated by solving the problem of global stabilization via bounded state feedback, for affine nonlinear systems with stable unforced dynamics. Analogous results are established for discrete-time nonlinear systems