In this paper, we present a new scheme to design an adaptive controller for uncertain nonlinear systems with unknown backlash, Coulomb friction nonlinearity. The control design is achieved by introducing a smooth approximate backlash model and certain well defined functions and by using backstepping technique. It is shown that the proposed controller can guarantee that the system is global asymptotic stable.
Adaptive Backstepping Control of Electrical Transmission Drives with Elastic, Unknown Backlash and Coulomb Friction Nonlinearity