Spectrum Analysis Additional Vibrations of Cartesian Robot by Different Control Modes

Abstract

Cartesian robot is a complex industrial robot, which is designed to work in hard and dangerous human conditions. This kind of robot has some control modes that help transform it for different tasks, such as movement details, 3D-printing, accuracy cutting processes, and others. Hirata cartesian robot is chosen for research in the paper. Additional vibrations occur in the industrial robot leading to unstable work. Usually, vibrations are occurred in mechanical parts of the industrial robot, like gearboxes, and joints. The problem with these parts is the impossibility to install any sensors for state monitoring oscillations. In this case, need to predict any mechanical faults or eliminate undesirable vibrations during the robot operations. This article considers belt over tension, as the origin of additional vibrations. Two types of control modes, manual and semiautomatic modes, are described in the paper. Also, fast Fourier transform and continuous wavelet transform are used for the analysis output signal. The first method is used for rapid damage assessment. The second method is used for the determination of the localization of damages. Experimental results, based on Hirata cartesian robot, are presented in the article.