Investigation of one equation of phase frequency self-adjustment in the vicinity of the soft excitation boundary

Reference [1] has shown that the results of investigating a sell-adjustment system by the Krylov — Bogolyubov technique do not necessarily coincide with those obtained by using the Lyapunov theory. The findings of Ref. [1] lead to formulation of conditions for generation of soft excitation in the system and in the space of dimensional parameters an estimate is given of the region for the points of which it does exist.