# 时域和频域分析

## App

 线性系统分析器 Analyze time and frequency responses of linear time-invariant (LTI) systems

## 函数

 `step` Step response plot of dynamic system; step response data `stepinfo` Rise time, settling time, and other step-response characteristics `impulse` Impulse response plot of dynamic system; impulse response data `initial` System response to initial states of state-space model `lsim` Plot simulated time response of dynamic system to arbitrary inputs; simulated response data `lsiminfo` Compute linear response characteristics `gensig` Create periodic signals for simulating system response with `lsim` `covar` Output and state covariance of system driven by white noise `RespConfig` Options for step or impulse responses
 `bode` Bode plot of frequency response, or magnitude and phase data `bodemag` Magnitude-only Bode plot of frequency response `nyquist` Nyquist plot of frequency response `nichols` Nichols chart of frequency response `ngrid` Superimpose Nichols chart on Nichols plot `sigma` Singular value plot of dynamic system `freqresp` Evaluate system response over a grid of frequencies `evalfr` Evaluate system response at specific frequency `dcgain` Low-frequency (DC) gain of LTI system `bandwidth` Frequency response bandwidth `getPeakGain` Peak gain of dynamic system frequency response `getGainCrossover` Crossover frequencies for specified gain `fnorm` Pointwise peak gain of FRD model `norm` Norm of linear model `db2mag` Convert decibels (dB) to magnitude `mag2db` Convert magnitude to decibels (dB)

## 实时编辑器任务

 创建绘图 Interactively create linear analysis response plots in the Live Editor

## 模块

 LTI System Use linear time invariant system model object in Simulink LPV System 对线性参数变化 (LPV) 系统进行仿真

## 主题

### 具有时滞的系统

• Analysis of Systems with Time Delays
The time and frequency responses of delay systems can have features that can look odd to those only familiar with delay-free LTI analysis.
• Analyzing Control Systems with Delays
Many processes involve dead times, also referred to as transport delays or time lags. Controlling such processes is challenging because delays cause phase shifts that limit the control bandwidth and affect closed-loop stability.