Identification of Dynamic Parameters of a Novel 3-DOF Spindle Head

Abstract

A methodology is presented to identify the dynamic parameters of a novel 3-DOF spindle head for high-speed machining of extra large components. The architecture behind the spindle head is a 3-RPS parallel mechanism having one translational and two rotational movement capabilities. The inverse kinematic and dynamic analyses are carried out in the first place, allowing the model suitable for dynamic parameter identification to be formulated by setting a characteristic reference point on each moving component.In the light of the load torques under different working conditions, a hierarchical strategy is proposed for dynamic parameter identification. The merit of this strategy lies in that it enables the influences due to the Coulomb frictions to be counteracted or eliminated via proper path planning, thereby the identification accuracy to be significantly improved. The experiments under various working conditions are carried out to verify the validity and effectiveness of the proposed approach.