International Journal of Control, Vol.85, No.4, 397-408, 2012
Low-sensitivity H-infinity filter design for linear delta operator systems with sampling time jitter
This article is concerned with the problem of designing H-infinity filters for a class of linear discrete-time systems with low-sensitivity to sampling time jitter via delta operator approach. Delta-domain model is used to avoid the inherent numerical ill-condition resulting from the use of the standard shift-domain model at high sampling rates. Based on projection lemma in combination with the descriptor system approach often used to solve problems related to delay, a novel bounded real lemma with three slack variables for delta operator systems is presented. A sensitivity approach based on this novel lemma is proposed to mitigate the effects of sampling time jitter on system performance. Then, the problem of designing a low-sensitivity filter can be reduced to a convex optimisation problem. An important consideration in the design of correlation filters is the optimal trade-off between the standard H-infinity criterion and the sensitivity of the transfer function with respect to sampling time jitter. Finally, a numerical example demonstrating the validity of the proposed design method is given.
Keywords:sensitivity;delta operator;sampling time jitter;H-infinity filter;descriptor system approach;linear matrix inequality