ANALYSIS OF OWN FREQUENCIES AND OSCILLATION FORMS OF A PLANE PARALLEL MANIPULATOR

Abstract

The study objective is to analyze the own frequencies and small-amplitude oscillations of a plane manipulator having parallel structure and to determine the influence of elastic and inertial properties of intermediate links and the drive on own frequencies and forms. The paper is devoted to solving the problem of ensuring vibration stability of manipulators. Analytical methods of the theory of oscillations and computational experiments in the software package "Universal Mechanism" are used. The novelty of the work is in defining the dependence of the own frequencies and oscillation forms of a plane parallel manipulator on the ratio of elastic and inertial properties of the links and the drive. As a result of the research, analytical and several computer models of a plane manipulator with three degrees of freedom are developed, own frequencies and oscillation forms for the developed models are determined. Conclusions: the replacement of absolutely rigid intermediate links with elastic rods led to the appearance of own frequencies and own modes corresponding to them , on which the output link oscillates in the vertical plane perpendicular to the plane of the manipulator links movement; the oscillations of the output link in the vertical and horizontal planes on their own forms are separated; the values of own frequencies at which the output link oscillates in the vertical plane do not depend on the coefficient of rigidity of the drive, but are determined by the elastic and inertial properties of the rods; the values of own frequencies at which the output link oscillates in the horizontal plane depend on the ratio of the drive and rods compliance; the influence of the elastic link masses on the values of their own frequencies is determined by the type of their own forms and the ratio of inertial parameters of the output link and rods.