LTR Animation

You're viewing this page with a browser that doesn't understand the APPLET tag. (Otherwise, you would have seen an inline animation here.)

If you have the Netscape v1.1 browser you can view it by starting a HTML page-by-page animation, clicking the "START" link below.

Finally, the animation can be viewed manually, by any browser that supports graphics.

The animation shows the

-iteration in the

/LTR approach described in:
Improved Recovery in /LTR Design
by Henrik Niemann, Jakob Stoustrup, and Bahram Shafai

The system is a time invariant, linear system with two nonminimum phase zeros at 3.4174 and 12.5826.

The performance objective is to recover a given target loop in mid frequencies (around 6-7 rad/sec) as specified by the weigthing shown by a dotted curve in the animation.

Note that this specification is difficult, because the desired frequency is in the frequency interval between the two nonminimum phase zeros!

The design result is shown as a solid curve. For comparison a classical LQG/LTR design is shown as well (dash-dotted curve).

The animation displays the following phenomena:

The waterbed effect
Improvement at mid frequencies
Bandwidth deterioration
The pointwise convergence of the curve to its weigthing

tends to its infimum (41.94). The plots show the Recovery Transfer Function which is an unbiased measure of the recovery error.

The bottomline is the following: using our approach you can recover dynamics at frequencies in between non minimum phase zeros, in contrast with traditional LTR.

CLICK HERE TO START the animation.

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