A new robust indirect adaptive control for torque-driven robot manipulators under relaxed excitation conditions

This paper presents a new robust adaptive joint position trajectory tracking control for torque-driven robot manipulators using a novel parameter identification scheme. The novelty of this identification scheme is that ensures convergence of the true parameters exponentially, even when the regressor do not verify the stringent condition of persistent excitation, using a classical normalized gradient descendent adaptive law. An indirect adaptive controller approach is used to combine the identification scheme with a robust model based GES controller to verify joint position trajectory tracking control objectives under constant disturbances. The validity of our claims are illustrated with simulations of a two degrees-offreedom robot manipulator.