Non-Local Methods for Pendulum-Like Feedback Systems

0 are already deecribed by I. Newton (116]. However it was 250 years later that F. Tricorni (147] carried out the first non-local qualitative investigation of equation (0.1) with arbitrary o ~ 0 and "'{ ~ 0. It was proved by F. Tricorni that any solution of (0.1) with o 0 corresponds either to a rotatory motion or to a damped oscillatory motion. Moreover, he showed that in the non-trivial case "'! :::; 1 there exists a bifurcation value ocr("'!) corresponding to a separatrix-loop, i.e. to a double-asymptotic to a saddle-point trajectory. For o ocr("'') global asymptotic stability takes place, i.e. every motion is a damped oscillation. The papers of F. Tricorni became familiar immediately. Inhaltsverzeichnis Systems with Multiple Equilibria.- Pendulum-Like Systems.- Invariant Cones.- The Bakaev-Guzh Technique.- The Method of Non-Local Reduction.- Circular Solutions and Cycles.- Synchronous Machines Equations.- Integro-Differential Equations.- Cycle Slipping in Phase-Controlled Systems.- Discrete Systems.