Nonlinear Grey-Box Models

Estimate coefficients of nonlinear differential, difference and state-space equations

Functions

`nlgreyest`	Estimate nonlinear grey-box model parameters
`idnlgrey`	Nonlinear grey-box model
`pem`	Prediction error minimization for refining linear and nonlinear models

`findstates`	Estimate initial states of model
`init`	Set or randomize initial parameter values
`getinit`	Values of `idnlgrey` model initial states
`setinit`	Set initial states of `idnlgrey` model object
`getpar`	Parameter values and properties of `idnlgrey` model parameters
`setpar`	Set initial parameter values of `idnlgrey` model object
`getpvec`	Obtain model parameters and associated uncertainty data
`setpvec`	Modify values of model parameters
`sim`	Simulate response of identified model

`nlgreyestOptions`	Option set for `nlgreyest`
`findstatesOptions`	Option set for `findstates`
`simOptions`	Option set for `sim`

Examples and How To

Estimate Nonlinear Grey-Box Models
How to define and estimate nonlinear grey-box models at the command line.
Creating IDNLGREY Model Files
This example shows how to write ODE files for nonlinear grey-box models as MATLAB® and C MEX files.
Estimate Coefficients of ODEs to Fit Given Solution
Estimate model parameters using linear and nonlinear grey-box modeling.

Concepts

Supported Grey-Box Models
Types of supported grey-box models.
Data Supported by Grey-Box Models
Types of supported data for estimating grey-box models.
Choosing idgrey or idnlgrey Model Object
Difference between idgrey and idnlgrey model objects for representing grey-box model objects.

Featured Examples

Modeling a Vehicle Dynamics System

Nonlinear grey-box modeling of vehicle dynamics.

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Modeling an Aerodynamic Body

The grey-box modeling of a large and complex nonlinear system.

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Modeling an Industrial Robot Arm

Grey-box modeling of the dynamics of an industrial robot arm.

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Represent Nonlinear Dynamics Using MATLAB File for Grey-Box Estimation

Construct, estimate, and analyze nonlinear grey-box models.

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Two Tank System: C MEX-File Modeling of Time-Continuous SISO System

Perform IDNLGREY modeling based on C MEX model files.

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Three Ecological Population Systems: MATLAB and C MEX-File Modeling of Time-Series

Create nonlinear grey box time series models.

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Narendra-Li Benchmark System: Nonlinear Grey Box Modeling of a Discrete-Time System

Identify the parameters of a complex yet artificial nonlinear discrete-time system with one input and one output.

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Friction Modeling: MATLAB File Modeling of Static SISO System

Grey-box modeling of a static single-input, single-output system using a MATLAB function as the ODE file.

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Signal Transmission System: C MEX-File Modeling Using Optional Input Arguments

Provide optional input arguments to IDNLGREY models.

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Dry Friction Between Two Bodies: Parameter Estimation Using Multiple Experiment Data

Estimate parameters of a nonlinear grey box model using multiple experiment data.

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Industrial Three-Degrees-of-Freedom Robot: C MEX-File Modeling of MIMO System Using Vector/Matrix Parameters

Design C-MEX model files that involve scalar, vector, and matrix parameters.

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Non-Adiabatic Continuous Stirred Tank Reactor: MATLAB File Modeling with Simulations in Simulink

Include and simulate an IDNLGREY model in Simulink^®.

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Classical Pendulum: Some Algorithm-Related Issues

How the estimation algorithm choices may impact the results for a nonlinear grey box model estimation.

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