A MODIFIED FREQUENCY-DOMAIN CRITERION FOR GRADIENT-LIKE BEHAVIOR OF DISCRETE PHASE SYSTEMS

Asymptotic behavior of a class of multidimensional discrete control systems with periodic nonlinearities and denumerable set of equilibria is investigated. By means of discrete version of Yakubovich-Kalman theorem and certain modification of Lur'e-Postnikov function a frequency-domain criterion which guarantees that every solution of a system tends to an equilibrium is obtained.