System Representation

Systems can be defined by Transfer Functions and State Space models. Both system representations provide near identical utility.

Transfer Functions

A Transfer Function is the Laplace Transform of the ratio of output to input, and are mathematically described as:

shared_images/tf.png

To define a system in terms of a Transfer Function, use the TransferFunction class.

>>> import control
>>> s = control.TransferFunction(num, den)

Here num and den can be lists or numpy arrays

State Space Models

Space State models are mathamatically described as:

_images/ss.png

To define a system as Space State model, use the StateSpace class.

>>> import control
>>> s = control.StateSpce(A,B,C,D)

Here, A,B,C,D are ndarrays.

Note

A system can be defined by any of the two representations above. If a particular method is needed but is not provided for the given system representation (which is unlikely), you can convert the system model to the desired representation using the convert2TF() or convert2SS() method.