Comparative Study on First and Second Order ILC -- Frequency Domain Analysis and Experiments

Abstract

Aspects on the behavior of a general second order iterative learning control (ILC) algorithm is presented from a frequency domain perspective. This includes stability as well as performance and robustness issues. The basis for the analysis is linear iterative systems and these are briefly described. A design algorithm for second order ILC schemes is proposed and analyzed both theoretically as well as in an experiment. In the experiment, done on a commercial industrial robot control system, the second order ILC design is compared with a first order ILC design. The result from both the analysis and the experiment is that the second order design is not better with respect to performance or robustness. 1 Introduction It is a fact that many systems in applications like robotics repeat the same actions over and over again. Often it is also the case that there is a di#erence between what wants to be achieved and what is actually achieved. The idea of iterative learning control (ILC) is to us...