Adaptive Estimation of Friction Forces under a Sector Condition

In this paper, we design an adaptive observer to estimate the nonlinear friction model with the position measurement. An adaptive observer is designed to estimate the nonlinear friction force with full-states measurement. The nonlinear friction is approximated by the fuzzy basis function expansion. An incremental sector condition as in Putra et al. are assumed. Moreover, we introduce an adaptive differential filter to estimates the velocity.