Friction diagnostics and modeling using DFT analysis

In this paper a new method of modeling nonlinear friction as a function of both position and velocity is introduced. The proposed empirical model uses spectral analysis to identify the main sources of position dependent friction in complex mechanisms. In addition, the model describes the contribution to the overall friction of every moving part of the mechanism. In the paper, the proposed spectral-based modeling technique is used to describe the static friction of the first joint of PUMA 560 robot. Development of a complete friction model, which describes both static and sliding friction of complex mechanisms as a function of position and velocity, is the topic of our future work