Rotor Model Updating and Validation for an Active Magnetic Bearing Based High-Speed Machining Spindle

This paper presents an experimentally driven model updating approach to address the dynamic inaccuracy of the nominal finite element (FE) rotor model of a machining spindle supported on active magnetic bearings. Modeling error is minimized through the application of a numerical optimization algorithm to adjust appropriately selected FE model parameters. Minimizing the error of both resonance and antiresonance frequencies simultaneously accounts for rotor natural frequencies as well as for their mode shapes. Antiresonance frequencies, which are shown to heavily influence the model’s dynamic properties, are commonly disregarded in structural modeling. Evaluation of the updated rotor model is performed through comparison of transfer functions measured at the cutting tool plane, which are independent of the experimental transfer function data used in model updating procedures. Final model validation is carried out with successful implementation of robust controller, which substantiates the effectiveness of the model updating methodology for model correction.

Rotor Model Validation for an Active Magnetic Bearing Machining Spindle Using Mu-Synthesis Approach

Model-based identification and μ-synthesis are employed for model updating of the rotor for a high-speed machining spindle supported on active magnetic bearings. The experimentally validated model is compared with a nominal engineering model to identify the unmodeled dynamics. The extracted missing dynamics from the nominal rotor model provides engineering insight into an effective model correction strategy. The corrected rotor model is validated by successful implementation of a number of μ-synthesized controllers, providing robust and stable levitation of the spindle over its entire operating speed range.

Rotor Model Validation for an Active Magnetic Bearing Machining Spindle Using mu-Synthesis Approach

Model-based identification and μ-synthesis are employed for model updating of the rotor for a high-speed machining spindle supported on active magnetic bearings. The experimentally validated model is compared with a nominal engineering model to identify the unmodeled dynamics. This extracted missing dynamics from the nominal rotor model provides engineering insight into an effective model correction strategy. The corrected rotor model is validated by successful implementation of a number of μ-synthesized controllers, providing robust and stable levitation of the spindle over its entire operating speed range.

Rotor Model Updating and Validation for an Active Magnetic Bearing Based High-Speed Machining Spindle

This paper presents an experimentally-driven model updating approach to address the dynamic inaccuracy of the nominal finite element (FE) rotor model of a machining spindle supported on active magnetic bearings. Modeling error is minimized through the application of a numerical optimization algorithm to adjust appropriately selected FE model parameters. Minimizing the error of both resonance and antiresonance frequencies simultaneously accounts for rotor natural frequencies as well as for their mode shapes. Antiresonance frequencies, which are shown to heavily influence the model’s dynamic properties, are commonly disregarded in structural modeling. Evaluation of the updated rotor model is performed through comparison of transfer functions measured at the cutting tool plane, which are independent of the experimental transfer function data used in model updating procedures. Final model validation is carried out with successful implementation of robust controller, which substantiates the effectiveness of the model updating methodology for model correction.