Getting Started

Discrete Time Systems

The Control Systems Toolbox provides full support for discrete time systems. You can create discrete systems in the same way that you create analog systems; the only difference is that you must specify a sample time period for any model you build. For example,

sys_disc = tf(1, [1 1], .01);

creates a SISO model in the transfer function format.

Transfer function:
  1
-----
z + 1
 

Sampling time: 0.01

Adding Time Delays to Discrete-Time Models

You can add time delays to discrete-time models by specifying an input or output time delay when building the model. The time delay must be a nonnegative integer that represents a multiple of the sampling time. For example,

sys_delay = tf(1, [1 1], 0.01,'outputdelay',5);

produces a system with an output delay of 0.05 second.

Transfer function:
           1
z^(-5) * -----
         z + 1
 
Sampling time: 0.01

Constructing SISO Models

Adding Delays to Linear Models