IEEE Transactions on Automatic Control, Vol.46, No.11, 1844-1845, 2001
Comments on "an exponentially stable adaptive friction compensator"
This note points out a technique error in the above paper. It is shown that without persistence excitation (PE) of the system signals, the estimated Coulomb friction parameter cannot be guaranteed to converge to its true value. An analysis is provided for the PE condition of parameter asymptotic convergence.