Flexible Robot Dynamics and Vibration: From Analytical Modeling to Operational Modal Analysis

This paper presents recent studies on the dynamics and vibration of a flexible robot developed for industrial use that features six degrees of freedom. The flexibility of the joints and links is considered. We investigate the nonlinear dynamics and non-stationary vibration behavior of the robot's structure during grinding applications using both analytical and experimental methods. A linearization technique is introduced for the analytical modeling of the robot's dynamics across its entire workspace. Experimental investigations include modal testing and operational modal analysis, utilizing autoregressive models (ARX) and the Kalman filter to accurately characterize the robot's dynamic properties, dynamic contact forces, and the adaptation of these parameters in non-stationary vibrations. The effective performance of both approaches and the congruence between analytical and experimental findings suggest the potential for a hybrid modal analysis technique, tailored for flexible structures and robots operating under complex, real-world conditions.