English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

Growing demands in the semiconductor industry result in the need for enhancedperformance of lithographic equipment. However, position tracking accuracy ofhigh precision mechatronics is often limited by the presence of disturbancesources, which originate from unmodelled or unforeseen deterministicenvironmental effects. To negate the effects of these disturbances, a learningbased feedforward controller is employed, where the underlying control policyis estimated from experimental data based on Gaussian Process regression. Theproposed approach exploits the property of including prior knowledge on theexpected steady state behaviour of residual dynamics in terms of kernelselection. Corresponding hyper-parameters are optimized using the maximizationof the marginalized likelihood. Consequently, the learned function is employedas augmentation of the currently employed rigid body feedforward controller.The effectiveness of the augmentation is experimentally validated on amagnetically levitated planar motor stage. The results of this paperdemonstrate the benefits and possibilities of machine-learning based approachesfor compensation of static effects, which originate from residual dynamics,such that position tracking performance for moving-magnet planar motoractuators is improved.

Learning-based feedforward augmentation for steady state rejection of residual dynamics on a nanometer-accurate planar actuator system