An elastodynamic modeling approach based on experimental substructuring for a mobile hybrid robot

Abstract

This paper presents an elastodynamic modeling approach based on experimental dynamic substructuring for a mobile hybrid robot that consists of a hybrid machining cell plus an omnidirectional mobile platform. In this method, the frequency response functions (FRFs) of the hybrid machining cell are predicted using the semi-analytical model. Then, the regenerated FRFs of the entire system are constructed using modal testing and parameter identification techniques. Subsequently, the FRFs matrix of the omnidirectional mobile platform is obtained by applying substructure decoupling technology to decouple the former from the latter. Finally, the dynamic model of the entire system is established by assembling the FRFs of the omnidirectional mobile platform and the hybrid machining cell using the substructure coupling technology. The proposed approach solves the problem related to the dynamic response of the hybrid machining cell, which cannot be measured separately by modal testing. The computational results show that the estimated lower-order natural frequencies and the FRFs at the endpoints of the entire system have very good agreement with those obtained by experimental modal testing, which demonstrates the effectiveness of the proposed approach.