Two adaptive friction compensations for DC servomotors

Two advanced control strategies of adaptive friction compensation for DC servomotor are presented, the first is used for the direct online friction compensation in the velocity control system, the second is making use of an adaptive inverse neural network controller in the position control system. Both are composed of an adaptive compensator for the nonlinear stiction and Coulomb friction in parallel with a PID regulator. Experiments show that much improvement of performance has attained respect to conventional controllers.