Getting Started

Feedback Interconnection

You can use the feedback and lft functions to derive closed-loop models. For example,

• sys_f = feedback(tf(1,[1 0]), tf([1 1],[1 2])
  

computes the closed-loop transfer function from r to y for the feedback loop shown in Figure 2-4. The result is

• Transfer function:
      s + 2
  -------------
  s^2 + 3 s + 1
  

This figure shows the interconnected system in block diagram format.

Figure 2-4: Feedback Interconnection

You can use the lft function to create more complicated feedback structures. This function constructs the linear fractional transformation of two systems. See the online reference page for more information.

Interconnecting Linear Models

Continuous/Discrete Conversions