@ARTICLE{Horla_D._LQG/LTR_2019,
 author={Horla, D. and Krolikowski, A.},
 volume={67},
 number={No. 6},
 journal={Bulletin of the Polish Academy of Sciences Technical Sciences},
 pages={1049-1058},
 howpublished={online},
 year={2019},
 abstract={A simple robust cheap LQG control is considered for discrete-time systems with constant input delay. It is well known that the full loop transfer recovery (LTR) effect measured by error function ∆(z) can only be obtained for minimum-phase (MPH) systems without time-delay. Explicit analytical expressions for ∆(z) versus delay d are derived for both MPH and NMPH (nonminimum-phase) systems. Obviously, introducing delay deteriorates the LTR effect. In this context the ARMAX system as a simple example of noise-correlated system is examined. The robustness of LQG/LTR control is analyzed and compared with state prediction control whose robust stability is formulated via LMI. Also, the robustness with respect to uncertain time-delay is considered including the control systems which are unstable in open-loop. An analysis of LQG/LTR problem for noise-correlated systems, particularly for ARMAX system, is included and the case of proper systems is analyzed. Computer simulations of second-order systems with constant time-delay are given to illustrate the performance and recovery error for considered systems and controllers.},
 type={Artykuły / Articles},
 title={LQG/LTR control of input-delayed discrete-time systems},
 URL={http://www.journals.pan.pl/Content/114320/PDF/07_1049-1058_01155_Bpast.No.67-6_13.01.20_K2_TeX.pdf},
 doi={10.24425/bpasts.2019.130895},
 keywords={LQG control, loop transfer recovery, time-delay},
}