TI89 PI tuning program.

This program tunes a Proportional + Integral (PI) controller for a typical process type transfer function

which is assumed to be type zero (no integrators) and to be such that the real part of
crosses the imaginary axis. The frequency at which real part of
first crosses the imaginary axis is called
. The PI controller transfer function is

.

The Nyquist plot of the tuned loop gain
is guaranteed to lie to the left of
.

Typically
for robustness.

.

1. Define the plant transfer function and run pitun from the command line. In this example
   .

Note Mode is set to RAD and APPROX.

2) The program outputs
,
and

3) Plant and loop Nyquist plots can be plotted in parametric mode.

The program is based on the following reference from which the above example is taken.

Ya-Gang Wang and Hui-He Shao

Optimal tuning for PI controller

Automatica 36 (2000)

pp 157-152

The pituning program pitun.89p is copyright (C) 2001 by Mark Readman

([e-mail]) and comes with ABSOLUTELY NO WARRANTY. It is

distributed free under the GNU General Public Licence.

Mark Readman

Control Systems Centre

Dept of Electrical Engineering and Electronics

UMIST

Manchester

M60 1QD

UK

[e-mail]

Plant Nyquist plot

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