# 离线频率响应估计

## 函数

#### 估计

 `frestimate` Frequency response estimation of Simulink models `frestimateOptions` Options for frequency response estimation

#### 输入信号

 `frest.Sinestream` Input signal containing series of sine waves `frest.createFixedTsSinestream` Sinestream input signal with fixed sample time `frest.Chirp` Swept-frequency cosine input signal `frest.PRBS` Pseudorandom binary sequence input signal (自 R2020a 起) `frest.Random` Random input signal `frest.createStep` Create step input signal
 `frest.simCompare` Plot time-domain simulation of nonlinear and linear models `frest.simView` Plot frequency response model in time- and frequency-domain `getSimulationTime` Final time of simulation for frequency response estimation
 `frest.findSources` Identify time-varying source blocks `frest.findDepend` List of model path dependencies

## 主题

### 频率响应估计基础知识

• Frequency Response Estimation Basics

A frequency response describes the steady-state response of a system to sinusoidal inputs. Simulink Control Design lets you estimate the frequency response of a model or perform online estimation of a physical plant.

• Analyze Estimated Frequency Response
When you perform frequency response estimation, you can analyze the result by examining the raw simulated response and the FFT used to convert it to an estimated frequency response.

### 估计输入信号

• Estimation Input Signals

For frequency response estimation, the software injects an input signal and measures the response. You can use predefined signal types such as sinestream or chirp signals, or create an arbitrary input signal.