Suppressing spatially distributed disturbances by exploiting additional sensors and actuators in inferential motion control

Structural deformations resulting from exogenous disturbances limit the control performance in high-precision positioning systems. The aim of this paper is to identify these limitations and mitigate these through multivariable inferential control. A systematic analysis and control design framework is established. Herein, additional sensors and actuators are exploited to achieve control performance beyond conventional limits. Successful performance enhancement using the presented methods is shown on an identified wafer stage model.