On Optimal Feedforward and ILC: The Role of Feedback for Optimal Performance and Inferential Control

Abstract The combination of feedback control with inverse model feedforward control or iterative learning control is known to yield high performance. The aim of this paper is to clarify the role of feedback in the design of feedforward controllers, with specific attention to the inferential situation. Recent developments in optimal feedforward control are combined with feedback control to jointly optimize a single performance criterion. Analysis and application show that the joint design addresses the specific control objectives. The combined design is essential in control, and in particular in inferential control.

[1]  John C. Doyle,et al.  Guaranteed margins for LQG regulators , 1978 .

[2]  Tae Tom Oomen,et al.  Resource-efficient ILC for LTI/LTV systems through LQ tracking and stable inversion: enabling large feedforward tasks on a position-dependent printer , 2016 .

[3]  Graham C. Goodwin,et al.  Fundamental Limitations in Filtering and Control , 1997 .

[4]  Michael J. Grimble,et al.  Iterative Learning Control for Deterministic Systems , 1992 .

[5]  Peter B. Goldsmith.  On the equivalence of causal LTI iterative learning control and feedback control , 2002, Autom..

[6]  Tom Oomen,et al.  Inferential Iterative Learning Control: A 2D-system approach , 2016, Autom..

[7]  Maarten Steinbuch,et al.  Model-based feedforward for inferential motion systems, with application to a prototype lightweight motion system , 2012, 2012 American Control Conference (ACC).

[8]  A.G. Alleyne,et al.  A survey of iterative learning control , 2006, IEEE Control Systems.

[9]  Frank Boeren,et al.  Enhancing feedforward controller tuning via instrumental variables: with application to nanopositioning , 2017, Int. J. Control.

[10]  Tae Tom Oomen,et al.  Estimating structural deformations for inferential control: a disturbance observer approach , 2016 .

[11]  Okko Bosgra,et al.  Fixed Structure Feedforward Controller Design Exploiting Iterative Trials: Application to a Wafer Stage and a Desktop Printer , 2008 .

[12]  B. Anderson,et al.  Optimal control: linear quadratic methods , 1990 .

[13]  Tom Oomen,et al.  Inferential Motion Control: Identification and Robust Control Framework for Positioning an Unmeasurable Point of Interest , 2015, IEEE Transactions on Control Systems Technology.