zn3fr

Ziegler-Nichols PID controller for processes of third order. The controller is based on forward rectangular method of discretization.

Transfer function of the controlled system:

Vector of identification initial parameter estimations:

Controller specific parameters:

None.

Control law:

where ek is control error (  ). This form of control law can be transformed to feedback form:

Controller parameters are calculated using following equations:

Variables  and  are ultimate gain and ultimate period respectively.

Source code:

sid

on-line identification s-function

zn3fr

function for computation of controller parameters

scqp

controller s-function

See also:

On-line identification methods

Computation of ultimate gain and period

List of common controllers parameters