Aerospace Instrument-Making Annotation << Back FRICTIONAL SELF-EXCITED OSCILLATIONS OF INDICATOR GYROSTABILIZER AS A MECHANICAL ANALOGUE OF THE FROUDE PENDULUM S.A. Chernikov There is discussed in this article the possibility of occurrence of self-excited oscillations in the indicator gyrostabilizer with dry friction (non-Coulomb friction) in the gimbal’s shaft in the process of base angular motion. Yet characteristics of dry friction, depending on the relative angular velocity of the rubbing surfaces is falling and growing areas and can be represented as the sum of the three components, one of which is Coulomb friction, the second (negative) is proportional to the sliding speed, the third is proportional to the cube of the slip rate. The negative characteristic slope of dry friction in the creeping speeds is typical for friction modes without lubricant or with inadequate lubrication, for example, for systems operating in the outer space. It is shown that a mechanical analogue for indicator gyrostabilizer with dry friction at the base angular motion is the Froude pendulum. In this case, the elastic connection of the stabilized platform with inertial space materialized by gyroscope is determined by amplifier gain Koc and is analogous to the elastic connection of the pendulum with a lead line. Spreading the results and methodology of numerous studies of the Froude pendulum dynamics on indicator stabilizer, it is shown due to the method of harmonic linearization that in such a system, stable on a fixed base, self-oscillations arise in the process of the base angular motion at speeds corresponding to the falling portion of the nonlinear characteristics of dry friction. The source of energy for self-excited oscillations that compensates its dispersion is the angular movement of the base. The results of the study of nonlinear system based on the method of harmonic linearization are verified by computer simulation of the original nonlinear system. Key words: self-excited oscillations, gyrostabilizer, dry friction, Froude pendulum. Contacts: E-mail: SA_chernikov@mail.ru Pp. 09-17.