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Advanced z-transform

From Wikipedia, the free encyclopedia

In mathematics and signal processing, the advanced z-transform is an extension of the z-transform, to incorporate ideal delays that are not multiples of the sampling time. The advanced z-transform is widely applied, for example, to accurately model processing delays in digital control. It is also known as the modified z-transform.

It takes the form

where

  • T is the sampling period
  • m (the "delay parameter") is a fraction of the sampling period

Properties

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If the delay parameter, m, is considered fixed then all the properties of the z-transform hold for the advanced z-transform.

Linearity

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Time shift

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Damping

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Time multiplication

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Final value theorem

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Example

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Consider the following example where :

If then reduces to the transform

which is clearly just the z-transform of .

References

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  • Jury, Eliahu Ibraham (1973). Theory and Application of the z-Transform Method. Krieger. ISBN 0-88275-122-0. OCLC 836240.