Adaptive backstepping control and friction compensation for ac servo with inertia and load uncertainties

An adaptive backstepping control with friction compensation scheme is presented. A third-order linear dynamic model is used for the AC motor control system design while the LuGre dynamic friction model with nonuniform friction force variations characterizes the friction force. Nonlinear adaptive control laws are designed to compensate the unknown system parameters and disturbances. System robustness and asymptotic position tracking performance are shown through simulation and experimental results.