Abstract
Iterative controller tuning is a method to fine-tune controllers in a repetitive process using only data collected in experiment runs. The controller parameters are chosen so as to minimize a certain cost function. The values of the parameters are updated iteratively based on tracking error in a gradient search. Iterative controller tuning is an advantageous method of controller tuning because no prior plant model is necessary. In this paper, we iteratively tune the feedforward controller of a wafer stage of a photolithography machine. A fixed-structure feedforward controller consisting of the inverted plant model was tuned. In addition, an additive feedforward term for compensation of nonlinear force ripple disturbance was tuned. The feedforward controller is tuned with the objective of minimizing a cost function that is a quadratic function of tracking error. Simulation and experimental results are presented which show that the iterative tuning method effectively reduced tracking error.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
