Modeling digital control systems with MA-prefiltered measurements

Three discrete state variable representations are derived for a continuous-time plant driven by a zero-order-hold with a combination of instantaneous measurements and measurements prefiltered by moving-average (MA) digital filters. These representations allow the control system engineer to accurately model plants of this type in a form which permits him to use standard techniques to design digital feedback controllers for them. An example is presented which illustrates how to obtain the coefficient matrices in each representation. Guidelines are presented for choosing the best representation to use for any given point.