Analysis of positivity and stability of fractional discrete-time nonlinear systems

The positivity and asymptotic stability of the fractional discrete-time nonlinear systems are addressed. Necessary and sufficient conditions for the positivity and sufficient conditions for the asymptotic stability of the fractional nonlinear systems are established. The proposed stability tests are based on an extension of the Lyapunov method to the positive fractional nonlinear systems. The effectiveness of tests is demonstrated on examples.