Nichtlinearität
Wenn Sie reale wissenschaftliche und technische Probleme lösen, müssen Sie oft Nichtlinearitäten modellieren. Simulink® bietet einen umfassenden Satz von Lookup-Tabellen-Blöcken, -Objekten und -Werkzeugen, die Sie zur effizienten Modellierung von Nichtlinearitäten verwenden können. Lookup-Tabellen ordnen Eingabewerte eines Systems seinen Ausgabewerten zu und speichern die zugeordneten Daten in einer Tabelle. Bei Echtzeitberechnungen verwenden die Lookup-Tabellen die gespeicherten Daten, um die Ausgaben zu ermitteln, die den verschiedenen Eingaben eines Systems entsprechen.
Mithilfe von Lookup-Tabellen-Blöcken, -Objekten und -Werkzeugen können Sie:
Zustandslose nichtlineare Systeme modellieren, indem Sie mathematische Funktionen oder experimentelle Daten mithilfe von Lookup-Tabellen approximieren.
Lookup-Tabellen innerhalb eines Workflows für Model-Based Design simulieren, analysieren und optimieren.
Lookup-Tabellen optimieren, um ein Gleichgewicht zwischen Speichernutzung, Ausführungsleistung und numerischer Genauigkeit herzustellen.
Für unterstützte Zielsprachen produktionsreifen Code mit industrieweit standardisierten Schnittstellen generieren.
Blöcke
| 1-D Lookup Table | Approximate one-dimensional function |
| 2-D Lookup Table | Approximate two-dimensional function |
| Direct Lookup Table (n-D) | Index into n-dimensional table to retrieve element, vector, or 2-D matrix |
| Interpolation Using Prelookup | Use precalculated index and fraction values to accelerate approximation of N-dimensional function |
| Lookup Table Dynamic | Approximate a one-dimensional function using dynamic table |
| n-D Lookup Table | Approximate n-dimensional function |
| Prelookup | Compute index and fraction for Interpolation Using Prelookup block |
| Sine, Cosine | Implement fixed-point sine or cosine wave using lookup table approach that exploits quarter wave symmetry |
Objekte
Simulink.LookupTable | Store and share lookup table and breakpoint data, and configure data for ASAP2 and AUTOSAR code generation |
Simulink.Breakpoint | Store and share data for breakpoint set, and configure the data for ASAP2 and AUTOSAR code generation |
Simulink.lookuptable.Evenspacing | Configure evenly spaced breakpoint set for lookup table object |
Simulink.lookuptable.Table | Configure table data for lookup table object |
Simulink.lookuptable.Breakpoint | Configure breakpoint set data for lookup table object |
Simulink.lookuptable.StructTypeInfo | Configure settings for structure type that lookup table object uses in generated code |
Tools
| Lookup TableEditor | Create, edit, and manage lookup tables in models (Seit R2022a) |
Themen
Arbeiten mit Lookup-Tabellen
- Edit Lookup Table Data with Lookup Table Spreadsheet
Work with lookup table objects with a lookup table spreadsheet. - Enter Breakpoints and Table Data
Specify breakpoint vectors and table data for lookup table blocks. - Import Lookup Table Data from MATLAB
You can import table and breakpoint data from variables in the MATLAB workspace by referencing them in the Table and Breakpoints tab of the dialog box. - Import Lookup Table Data from Excel Using readtable
Import data into a lookup table with thereadtablefunction. - Visualize Lookup Tables Visualized Through Lookup Table Control
Work with custom lookup tables from the Lookup Table Control. - Register Custom Lookup Table Blocks
You can use the Lookup Table Editor to register custom lookup table blocks that you have created. - Create a Logarithm Lookup Table
Work with lookup table blocks. - Optimize Generated Code for Lookup Table Blocks
Optimize code for lookup table blocks. - Row-Major Algorithm in Existing Models Containing Lookup Table Blocks
Update existing models to use row-major layout. - Optimize Lookup Tables for Memory-Efficiency (Fixed-Point Designer)
Optimize Lookup Tables using the Lookup Table Optimizer.
Informationen über Lookup-Tabellen
- About Lookup Table Blocks
A lookup table block uses an array of data to map input values to output values, approximating a mathematical function. - Anatomy of a Lookup Table
Breakpoint and table data are components of a lookup table. - Breakpoint and Table Size Features in Lookup Tables
Simulink lookup tables have multiple breakpoint and table size features. - Guidelines for Choosing a Lookup Table
Select the best lookup table for your application. - Prelookup and Interpolation Blocks
Use Prelookup and Interpolation Using Prelookup blocks together. - Characteristics of Lookup Table Data
Comply with lookup table data requirements and represent discontinuous data. - Methods for Approximating Function Values
Set the method by which lookup table blocks approximate function values.
Aktualisierung von Lookup-Tabellen aus älteren Versionen
- Update Lookup Table Blocks to New Versions
Update existing models to use current versions of lookup table blocks.
Enthaltene Beispiele
Modellieren eines Anti-Blockier-Bremssystems
Dieses Beispiel zeigt, wie Sie ein einfaches Anti-Blockier-Bremssystem (ABS) modellieren können. Das Modell simuliert das dynamische Verhalten eines Fahrzeugs bei starkem Bremsen. Das Modell stellt ein einzelnes Rad dar, das mehrfach nachgebildet werden kann, um ein Modell für ein mehrrädriges Fahrzeug zu erstellen.
Design a Guidance System in MATLAB and Simulink
Use the model of the missile airframe presented in a number of published papers on the use of advanced control methods applied to missile autopilot design. See [1], [2], and [3]. The model represents a tail-controlled missile traveling between Mach 2 and Mach 4, at altitudes ranging between 10,000 ft (3,050 m) and 60,000 ft (18,290 m), with typical angles of attack ranging between +/- 20 degrees.
Temperature Measurement System Using Nonlinear Behavioral Data of Type S Thermocouple
Build and simulate a temperature measurement system that uses a nonlinear dataset describing the behavior of a type S thermocouple.
Using the Prelookup and Interpolation Blocks
Use the Prelookup and Interpolation Using Prelookup blocks.
Saving Memory in Prelookup and Interpolation Blocks by Using Smaller Data
Save memory in Prelookup and Interpolation blocks. The Prelookup and Interpolation Using Prelookup blocks allow you to explicitly set data type storing breakpoints and table data. Note that the Prelookup block allows the breakpoint data to differ from the input data type, and the Interpolation Using Prelookup block allows the table data to differ from the output data type.
