In order to simplify the parameter

In order to simplify the parameter estimation, the high order dynamics of the amplifier are ignored and only a constant amplifier gain ( Ka ) is considered. The effective frequency range of the current amplifier. The drive parameters were estimated using the Least Squares technique developed in [12]. A sequence of piecewise constant current commands were applied as the identification input. This input signal was selected in a form which excites the dynamics of interest for Lease Squares identification; that is, the pulse signals are large enough to produce high acceleration for identifying the inertia parameter, and long enough to result in high velocities for identifying the viscous damping parameter. Also, the amplitude of the pulses is varied in order to account for the amplitude dependency caused by the Coulomb friction term.The values of parameters estimated are summarized in Table I. As mentioned earlier, the equivalent inertia was also calculated analytically using the table and air bushing masses and ball screw, coupling, and motor inertia values..This error could originate from the simplifying assumptions made when calculating the inertia of various mechanical components, including the ball screw. It could also originate from the discrepancy between the rated and actual amplifier gains and motor torque constants. Nevertheless, there is reasonable match between analytically computed and experimentally identified inertia parameters.