Next-generation wafer stage motion control : connecting system identification and robust control

Next-generation precision motion systems are lightweight to meet stringent requirements regarding throughput and accuracy. Such lightweight systems typically exhibit lightly damped flexible dynamics in the controller cross-over region. State-of-the-art modeling and motion control design procedures do not deliver the required model fidelity to control the flexible dynamical behavior. In this paper, identification and control challenges are investigated and a novel approach for next-generation motion control is presented. The procedure is applied to a multivariable wafer stage, confirming a significant performance improvement