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Article
Combined H∞-feedback Control and Iterative Learning Control Design with Application to Nanopositioning Systems
IEEE Transactions on Control Systems Technology
  • Brian E. Helfrich
  • Chibum Lee
  • Douglas A. Bristow, Missouri University of Science and Technology
  • Jingyan Dong
  • Srinivasa M. Salapaka
  • Placid M. Ferreira
  • X. H. Xiao
  • Andrew G. Alleyne
Abstract

This paper examines a coordinated feedback and feedforward control design strategy for precision motion control (PMC) systems. It is assumed that the primary exogenous signals are repeated; including disturbances and references. Therefore, an iterative learning control (ILC) feedforward strategy can be used. The introduction of additional non-repeating exogenous signals, including disturbances, noise, and reset errors, necessitates the proper coordination between feedback and feedforward controllers to achieve high performance. A novel ratio of repeated versus non-repeated signal power in the frequency domain is introduced and defined as the repetitive-to-non-repetitive (RNR) ratio. This frequency specific ratio allows for a new approach to delegating feedback and feedforward control efforts based on RNR value. A systematic procedure for control design is given whereby the feedback addresses the non-repeating exogenous signal content ( RNR < 0 dB}) and the feedforward ILC addresses the repeating signal content ( RNR > dB). To illustrate the design approach, two case studies using different nano-positioning devices are given.

Department(s)
Mechanical and Aerospace Engineering
Sponsor(s)
Nano-CEMMS Center, University of Illinois
Keywords and Phrases
  • Iterative Learning Control (ILC),
  • Nanopositioning,
  • Precision Motion Control (PMC)
Document Type
Article - Journal
Document Version
Final Version
File Type
text
Language(s)
English
Rights
© 2010 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.
Publication Date
3-1-2010
Publication Date
01 Mar 2010
Citation Information
Brian E. Helfrich, Chibum Lee, Douglas A. Bristow, Jingyan Dong, et al.. "Combined H∞-feedback Control and Iterative Learning Control Design with Application to Nanopositioning Systems" IEEE Transactions on Control Systems Technology (2010) ISSN: 1063-6536
Available at: http://works.bepress.com/douglas-bristow/15/