Title :
Synthesis of Variable Gain Integral Controllers for Linear Motion Systems
Author :
Hunnekens, Bram ; van de Wouw, N. ; Heertjes, Marcel ; Nijmeijer, H.
Author_Institution :
Dept. of Mech. Eng., Eindhoven Univ. of Technol., Eindhoven, Netherlands
Abstract :
In this paper, we introduce a design framework for variable gain integral controllers with the aim to improve transient performance of linear motion systems. In particular, we focus on the well-known tradeoff introduced by integral action, which removes steady-state errors caused by constant external disturbances, but may deteriorate transient performance in terms of increased overshoot. We propose a class of variable gain integral controllers (VGICs), which limits the amount of integral action if the error exceeds a certain threshold, in order to balance this tradeoff in a more desirable manner. The resulting nonlinear controller consists of a loop-shaped linear controller with a variable gain element. The utilization of linear controllers as a basis for the control design appeals to the intuition of motion control engineers therewith enhancing the applicability. For the add-on part of the nonlinear variable gain part of the controller, we propose an optimization strategy, which enables performance-optimal tuning of the variable gain based on measurement data. The effectiveness of VGIC is demonstrated in practice on a high-precision industrial scanning motion system.
Keywords :
control system synthesis; gain control; linear systems; motion control; nonlinear control systems; optimisation; VGIC; control design; high-precision industrial scanning motion system; integral action; linear motion systems; loop-shaped linear controller; measurement data; motion control engineers; nonlinear controller; nonlinear variable gain; optimization strategy; performance-optimal tuning; variable gain element; variable gain integral controller synthesis; Asymptotic stability; Gain; Stability analysis; Steady-state; Transfer functions; Transient analysis; Tuning; Motion control; transient performance; variable gain control; wafer scanners; wafer scanners.;
Journal_Title :
Control Systems Technology, IEEE Transactions on
DOI :
10.1109/TCST.2014.2315657