Beyond Quantization in Iterative Learning Control: Exploiting Time-Varying Time-Stamps

Equidistant sampling in control system may lead to quantization errors for certain measurement equipment, e.g., encoders. The aim of this paper is to develop an Iterative Learning Control (ILC) framework that eliminates quantization by exploiting time stamping. The developed ILC framework employs the non-equidistant time stamps in a linear time-varying (LTV) approach. Since the data at the time-stamps does not suffer from quantization, unparalleled performance can be achieved, while the intersample behaviour is bounded by definition. A simulation example confirms superiority of the ILC framework which employs time stamping.