传递函数模型

传递函数模型使用多项式的比率描述系统输入和输出之间的关系。模型阶数等于分母多项式的阶数。分母多项式的根称为模型极点。分子多项式的根称为模型零点。

传递函数模型的参数是其极点、零点和传输延迟。

在连续时间下，传递函数模型采用以下形式：

$Y (s) = \frac{n u m (s)}{d e n (s)} U (s) + E (s)$

这里，Y(s)、U(s) 和 E(s) 分别表示输出、输入和噪声的拉普拉斯变换。num(s) 和 den(s) 表示定义输入和输出之间的关系的分子和分母多项式。

App

系统辨识	从测量数据辨识动态系统模型

`idtf`	Transfer function model with identifiable parameters
`tfest`	估计传递函数模型
`pem`	Prediction error minimization for refining linear and nonlinear models
`spectrumest`	Estimate transfer function model for power spectrum data (自 R2022b 起)

`delayest`	根据数据估计时间延迟（死区时间）
`init`	Set or randomize initial parameter values

`tfdata`	访问传递函数数据
`getpvec`	Obtain model parameters and associated uncertainty data
`setpvec`	Modify values of model parameters
`getpar`	Obtain attributes such as values and bounds of linear model parameters
`setpar`	Set attributes such as values and bounds of linear model parameters
`addMinPhase`	Add minimum phase to frequency response magnitude (自 R2022b 起)

`tfestOptions`	Option set for `tfest`
`spectrumestOptions`	Option set for `spectrumest` (自 R2022b 起)

What Are Transfer Function Models?
Transfer function models describe the relationship between the inputs and outputs of a system using a ratio of polynomials.
Estimate Transfer Function Models in the System Identification App
Use the app to set model configuration and estimation options for estimating a transfer function model.
在命令行估计传递函数模型
在命令行估计传递函数模型的一般工作流程。
Data Supported by Transfer Function Models
Characteristics of estimation data for transfer function identification.

通过指定极点点数估计传递函数模型
此示例显示如何辨识包含给定数据指定数量极点的传递函数。
Estimate Transfer Function Models with Transport Delay to Fit Given Frequency-Response Data
This example shows how to identify a transfer function to fit a given frequency response data (FRD) containing additional phase roll off induced by input delay.
Estimate Transfer Function Models with Prior Knowledge of Model Structure and Constraints
This example shows how to estimate a transfer function model when the structure of the expected model is known and apply constraints to the numerator and denominator coefficients.
Estimate Transfer Functions with Delays
This example shows how to estimate transfer function models with I/O delays.
Estimate Transfer Function Models with Unknown Transport Delays
This example shows how to estimate a transfer function model with unknown transport delays and apply an upper bound on the unknown transport delays.

Troubleshoot Frequency-Domain Identification of Transfer Function Models
Improve frequency-domain model estimation by preprocessing data and applying frequency-dependent weighting filters.

Transfer Function Structure Specification
Specify the values and constraints for the numerator, denominator and transport delays.
Specifying Initial Conditions for Iterative Estimation of Transfer Functions
Specify how initial conditions are handled during model estimation in the app and at the command line.

此示例说明如何根据测量信号数据估计传递函数。

此示例显示如何根据频率响应数据估计传递函数。