Library for Aircraft Dynamics And Control (LADAC)

This project is a library with functions for aircraft dynamics and control for Matlab/Simulink. Examples of how to use LADAC are available in LADAC-Examples.

Motivation

This is the main motivation and objective of LADAC:

• Functions in LADAC can be used in different projects. Functions that are generally usable in multiple projects should be located in LADAC instead of copied/developed in multiple projects.
• LADAC is related to the Matlab Aerospace Blockset but also contains several functions that are not available in the Aerospace Blockset.
• The Simulink blocks are based on Matlab functions saved as m-files. This improves the use of version control. Diffs can be made easier and the data size of the repository is reduced.
• It is possible to generate C/C++ code of the library functions.
• All functions are carefully documented using comments in the code. This includes literature references to make scientific use easier.

Installation

• MATLAB:
  1. You need MATLAB/Simulink 2018b (later is also possible). If you want to use older versions, you will have to export the .slx file in older version format before.
  2. You may also need some MATLAB toolboxes like Curve Fitting Toolbox, MATLAB Coder, Embedded Coder, Simulink Coder Simulink Control Design depending on what you want to do
• Clone LADAC including its submodules (generally the main branch should be used).
  • If your project is a Git repository, you should add LADAC as a submodule:

    git add submodule https://github.com/iff-gsc/ladac.git
    

  • Otherwise, just clone LADAC to the desired directory:

    git clone --recursive https://github.com/iff-gsc/ladac.git
    

• Add LADAC folder to the Matlab path (in Matlab Command Window):

  addpath(genpath('ladac'));
  

Tests

1. Check if LADAC functions work by calling the automatic test framework (in Matlab Command Window):

   check_ladac
   

2. Check if LADAC appears in the Simulink Library Browser:
   • Open a Simulink file.
   • Open the Simulink Library Browser.
   • Look for "LADAC" at the highest level (you may have to refresh the Library Browser by right-clicking or pressing F5). This will probably only work if you use the supported Matlab version.
   • Check whether all sub-areas of LADAC appear and if you can add blocks to your Simulink file. Alternatively, you can add blocks by opening ladac_lib.slx (you can click through the sub-areas and add blocks by copy and paste).

How to use?

Introduction

• Get to know the range of functions. LADAC is divided into several sections. These areas are partly subdivided again into subareas. Each area and subarea is located in a folder or subfolder (see Contents).
• Usually each folder or subfolder contains a separate README with specific information.
• Most of the implementations are m-functions that are documented inside the code.
• Each subdirectory contains a Simulink library file (.slx) with the same name as the subdirectory. These libraries contain blocks which call the m-functions. There are also more complex blocks, but they are always based on the m-functions.

Contents

• Actuators
  The actuators library contains typical models for actuator dynamics and other functions related to actuators.
• Aerodynamics
  The aerodynamics library contains multiple models to compute aerodynamic forces and moments for wings, rotorcrafts, airfoils and fuselages based on different methods.
• Aircraft
  The aircraft library contains complete aircraft models as well as subsystems of aircraft.
• Control
  The control library contains basic modules to control different types of aircraft with different control methods.
• Environment
  The environment library contains modules to compute environmental parameters such as wind, atmospheric parameters and ground forces.
• Equations of motion
  The equations of motion library contains multiple implementations of rigid-body and flexible-body equations of motion.
• Flight parameters
  The flight parameters library allows the computation of flight parameters such as aerodynamic angles, flight path angles or time-derivatives of Euler angles.
• Propulsion
  The propulsion library contains sublibraries to model propellers, motors or batteries.
• Sensors
  The sensor library contains models that compute outputs for different sensors.
• Utilities
  The utilities library contains multiple sublibraries with miscellaneous functions such as axes transformation, interfaces to external programs and unit conversions

Modeling and control of systems

• Use LADAC as Git submodule.
• Build your models using the LADAC library blocks.
• Make yourself familiar with working with libraries:
  • Read the Matlab documentation, e.g. https://www.mathworks.com/help/simulink/ug/creating-and-working-with-linked-blocks.html
  • Hint: display links of library blocks: Display → Library Links → All

Anything missing in LADAC?

• Make sure you did not overlook the required function.
• Consider modifying existing functions if it is about input data handling or consider contributing new functions (see Contribute section).

Contribute

Contributions are welcome and encouraged. You can contribute in many ways:

• implement a new feature in the software
  → read developers guide.
• fix a bug
  → read developers guide.
• documentation updates and corrections
  → read developers guide.
• report a bug
  → create an issue
• new feature ideas & suggestions
  → create an issue

Before creating new issues please check to see if there is an existing one.