Identification of mechanical parameters at low velocities for a micropositioning stage using a velocity hysteresis model

Abstract

The paper presents a velocity hysteresis friction model. This model can be used for simulation or control of an accurate micropositioning servomechanism. The mechanical and friction parameters are identified from measured signals at low velocities, and with the use of a closed loop identification method. The measured signals are very noised. The number of measurement samples available is very low. The friction model dépends on position, velocity and acceleration and includes the Coulomb, Stribeck and viscous frictions. A hystérésis effect integrated by an exponential term and the acceleration is added in the model. The identified parameters are validated by applying an efficient precision method based on the sensitivity analysis of nonlinear models and a normalized mean-square-error criterion.