Flexible Multibody Modeling for Structural Flexibility Analysis of a Robotic Manipulator

A recent trend in robotics is the development of lightweight manipulators. Safety, power consumption, and productivity can significantly benefit of weight reductions. However, a lightweight design can significantly affect stiffness and accuracy performance. Accordingly, this paper investigates the effect of joint and link flexibility for an in-depth understanding of their contributions towards an optimal trade-off design of lightweight manipulators. The proposed work is based on using Flexible Multibody (FMB) simulations. The structural flexibility of a whole manipulator is evaluated by calculating a set of Frequency Response Functions (FRF) at different robot poses. Namely, a simplified model of an anthropomorphic robot is simulated within a multibody simulation environment. The results of the multibody simulations are analyzed and compared with finite element analyses. Results are discussed for two specific robot configurations.