Linearization involves creating a linear approximation of a nonlinear system that is valid in a small region around the operating point (or trim point), a steady-state condition in which all model states are constant. Linearization is needed to design a control system using classical design techniques, such as bode plot and root locus design. It also lets you analyze system behavior, such as system stability, disturbance rejection, and reference tracking.
Simulink Control Design™ lets you perform linearization of a nonlinear Simulink® model to produce a linear state-space, transfer function, or pole-zero-gain model. You can use these models to:
An alternative to linearization is feeding input signals through the model and calculating frequency response from the simulation output and input. You can use frequency response estimation when the model cannot be linearized because of event-based dynamics, such as those associated with pulse-width modulation and Stateflow® diagrams. Simulink Control Design provides functions that enable you to calculate frequency response with just a few lines of code, without making changes to the model.