Control System Toolbox

Creating and Manipulating Linear Models

Control System Toolbox lets you create and manipulate linear models of your control system as objects. All standard model representations are supported, including transfer function, zero-pole-gain, explicit and descriptor state space, and frequency-response data. Linear models can be SISO or MIMO, and continuous or discrete. You can represent PID controllers as PID objects. In addition, you can accurately model and simulate systems with time delays, including feedback loops with delays.

Control System Toolbox provides commands for:

• Performing arithmetic on linear models
• Building complex block diagrams by connecting simple models in series, parallel, or feedback
• Discretizing continuous-time models
• Computing low-order approximations of high-order models

Building a linear model of your plant is usually the first step in designing a control system. If no linear model is available, you can build one by fitting test data using System Identification Toolbox™, or by linearizing a Simulink model using Simulink Control Design. Once you have created a linear model, you can use Control System Toolbox to analyze it and design a controller.

MATLAB code for creating and analyzing a feedback loop with controller C and plant model G. The plant is modeled as a first-order transfer function with a delay of T seconds.