Novel observer-based suboptimal digital tracker for a class of time-delay singular systems

This paper presents a novel suboptimal digital tracker for a class of time-delay singular systems. first,some existing techniques are utilized to obtain an equivalent regular time-delay system,which has a direct transmission term from input to output. the equivalent regular time-delay system is important as it enables the optimal control theory to be conveniently combined with the digital redesign approach. the linear quadratic performance index,specified in the continuous-time domain,can be discretized into an equivalent decoupled discrete-time performance index using the newly developed extended delay-free model. additionally,although the extended delay-free model is large,its advantage is the elimination of all delay terms (which included a new extended state vector),simplifying the proposed approach. as a result,the proposed approach can be applied to a class of time-delay singular systems. an illustrative example demonstrates the effectiveness of the proposed design methodology. © 2013 nien-tsu hu et al.