Abstract: The fully compliant robotic mechanism is a new type of mechanism, and it is widely used in the high-precision applications. Considering that some imperfect structural dynamic characteristics of a fully compliant robotic mechanism such as its lower natural frequency may bring a negative influence on its positioning accuracy, it is necessary to discuss the structural dynamics of the mechanism in detail. To specify it, three methods to analyze the structural dynamics of a general fully compliant robotic mechanism, I.e. simplified theoretical modeling, Finite element analysis (FEA), and experimental measurement are addressed. In addition, taking a concrete fully compliant robotic mechanism (3-RRPR mechanism) for instance, its simplified model is formulated to predict the natural frequencies of the mechanism; The modal analysis of the mechanism is carried out by means of a finite element method. Experiments are conducted to measure the modal frequencies of the robot. The results obtained from simplified formulation, FEA and experiments are analyzed. Results of both FEA and experiment verify the accuracy of the theoretical model.

Key words: Compliant mechanism, Finite element, Flexure hinge, Robot, Structural dynamics