Yu Jingjun  Bi Shusheng  Zong Guanghua

(Robotics Institute, Beijing University of Aeronatics and Astronatics, Beijing 100083)

Liu Jigang

(School of Mechanical Engineering, Yanshan University, Qinhuangdao 066004)

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  Structural dynamics  Robot  Finite element  Flexure hinge

CLC No: TP24

国家自然科学基金(50075010)和国家863计划(2002AA404460)资助项目. Received 20030224, received in revised form 20040315