# Nichols Plot Generator

Description| How it works| Gain and Phase MarginsThis app will generate the Nichols Plot given a transfer function of the form

F(s) = (a + bs) e

^{-ts}/ (g + hs).

Nichols plot shows open loop gain in decibels against open loop phase shift. It allows easy determination of robustness margins.

## Download

.xlsx file (42 KB)## How to use

The use of this app is quite straightforward, simply key in the values of a, b, g, h and t into the cells B6 through B10. Key in the frequency range into the cells B13 and B14. Note that the units of frequency is rad/time. The Nichols plot is generated.Lets say we wish to obtain the Nichols plot of 2e

^{-3s}/(1 + 5s), from 0.01 rad/s to 100 rad/s. We have

a = 2,

b = 0,

g =1,

h = 5 and

t = 3.

Key in these values and the range. If done correctly, you should see the screen below.

## Also See:

PID Loop SimulatorLaplace to Time Domain Converter

Nyquist Plot Generator

PI Control of First Order Process

PI Control of Integrating Process