Adaptive fault-tolerant control of an electromechanical actuator considering viscous and static Friction

The article proposes an adaptive control law to compensate input faults in an electromechanical actuator aiming to restore the output to a desired trajectory. The adaptive control approach explicitly considers in the design both Coulomb and viscous friction, using a smooth model for the static friction term. The proposed adaptive algorithm proves to be useful even in the case of parametric uncertainty, rendering the system globally asymptotically stable. Through simulations, the authors demonstrate the efficacy of the proposed scheme, showcasing the performance under parametric uncertainty and input fault.