Cohen-Coon Autotuning Method

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Updated2026-01-28
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The Cohen-Coon autotuning method is an offline method for tuning PID controllers. This method uses PID parameters obtained from an open-loop transfer function experiment. This method is similar to the Ziegler-Nichols method, but provides better results when the controller has a large deadtime T_d relative to the time constant T.

Note You must use the PID Autotuning Design VI to implement this autotuning method.

The following table shows the Cohen-Coon recommendations for tuning parameters under different tuning specifications:


Controller	K_c	T_i	T_d
P	$\frac{T}{K_{c} * T_{d}} [1 + \frac{T_{d}}{3 T}]$	—	—
PI	$\frac{T}{K_{c} * T_{d}} [0.9 + \frac{T_{d}}{12 T}]$	$\frac{T_{d} [30 + 3 (\frac{T_{d}}{T})]}{9 + 20 (\frac{T_{d}}{T})}$	—
PID	$\frac{T}{K_{c} * T_{d}} [\frac{4}{3} + \frac{T_{d}}{4 T}]$	$\frac{T_{d} [32 + 6 (\frac{T_{d}}{T})]}{13 + 8 (\frac{T_{d}}{T})}$	$\frac{4 T_{d}}{11 + 2 (\frac{T_{d}}{T})}$

Where T is the time constant

K_c is the proportional gain

T_d is the deadtime

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Cohen-Coon Autotuning Method