固定翼无人机滑翔机附matlab代码.zip

# Simulation of a Fixed-Wing Unmanned Aerial Glider ## Table of Content [Overview](#overview) [Installation](#installation) [Airframe](#airframe) [Reference Frames](#referenceframes) [How to Run the Code](#applications) [Results](#results) [References](#references) ## <a name="overview"></a> Overview An example of a non-linear flight simulation for a unmanned aerial glider with a wingspan of 1.5m. The simulation is implemented with Matlab Simulink and uses [FlightGear](http://www.flightgear.org) for visualization purposes. In addition to existing Simulink examples from the Mathworks documentation, this implementation shows how to: 1. [Compute the required aerodynamic coefficient tables](./ExperimentalCarrierSimulink/code/mainComputeCoefficients.m) using [Tornado](http://tornado.redhammer.se/) an implementation of the [vortex lattice method](https://en.wikipedia.org/wiki/Vortex_lattice_method) (VLM). For more information on the Tornado implementation, see also [[1]](#tornado). 2. [Find the trimmed gliding state and deduce longitudinal and lateral linear time invariant systems](./ExperimentalCarrierSimulink/code/mainComputeLTIs.m) ([LTI](https://en.wikipedia.org/wiki/Linear_time-invariant_theory)) for the trimmed state according to text book definitions such as the one described in [[2]](#caughey). Simulation | Real Flight ----------| ------------ <img src="./figures/FlightGear03.png" width="400"> | <img src="./figures/Airframe02.png" width="400"> Visualization of the Simulink simulation with FlightGear | Test flight with the real airframe Lateral LTI | Longitudinal LTI -----------|------------- <img src="./results/mainComputeLTIs/lateral.png" width="400"> | <img src="./results/mainComputeLTIs/longitudinal.png" width="400"> Characteristics of the corresponding lateral LTI system | Characteristics of the corresponding longitudinal LTI system ## <a name="installation"></a>Installation and Configuration Besides Matlab and Simulink, you need to install [FlightGear](http://www.flightgear.org/) and [Tornado](http://tornado.redhammer.se/). ### FlightGear Installation After installing FlightGear, it is necessary to copy the aircraft visualization data from your Git working copy to the FlightGear data directory. Assuming you installed FlightGear 3.4.0 on Windows, just copy the content of the working copy folder `FlightGear\Aircraft\ExperimentalCarrier` to `C:\Program Files\FlightGear 3.4.0\data\Aircraft\ExperimentalCarrier`. For other versions or operating systems, proceed accordingly. Edit the files `runFlightGear.bat` and `runFlightGear.m` in `ExperimentalCarrierSimulink/utilities` and adjust the FlightGear installation path to point to the correct location. ### Tornado Installation Download Tornado [here](http://tornado.redhammer.se/index.php/download) and unzip it anywhere convenient, for example to `C:\tornado\T135_export`. #### Install the Airframe and Airfoil Definitions To install the airframe definition, copy [ExperimentalCarrier.mat](./Tornado/aircraft/ExperimentalCarrier.mat) to `T135_export/aircraft`. To install the airfoil, copy also [JR001.dat](./Tornado/aircraft/airfoil/JR001.DAT) to `T135_export/aircraft/airfoil`. #### Get Rid of Interp1 Warnings in Tornado Edit `T135_export\fLattice_setup2.m` and replace in calls to `interp1` (4 locations) `cubic` with `pchip`. This will fix the Matlab warning ``` Warning: INTERP1(...,'CUBIC') will change in a future release. Use INTERP1(...,'PCHIP') instead. ``` #### Configure the Tornado Installation Directory Assuming you have installed Tornado under `C:\tornado\T135_export`. Edit [`mainComputeCoefficients.m`](./ExperimentalCarrierSimulink/code/mainComputeCoefficients.m) and [`mainComputeLTIs.m`](./ExperimentalCarrierSimulink/code/mainComputeLTIs.m) in `ExperimentalCarrierSimulink/code` and adjust the `tornado_root_directory` variable definition to point to the Tornado root directory, e.g.: ``` tornado_root_directory = 'C:\tornado\T135_export'; ``` You can now run the simulation. Jump [here](#applications) to see how, or continue reading to learn about the airframe and the relevant reference frames first. ## <a name="airframe"></a>Airframe The simulated airframe has a twin-boom fuselage and a wing with upward cranked tips. The total wing span is 1.5m and the take-off weight is 1.56kg (actual glider equiped with on-board computer and temporarily installed electric motor for testing / take-off). Center of gravity has been found to be at 92mm from the leading edge of the main wing. Via GPS measurements a gliding velocity of about 45km/h was confirmed (at roughly zero elevator deflection). The glider uses two actuators: elevator and rudder. The rudder is asymmetrically attached to the left of the two vertical stabilizers. Below is the airframe as defined for the vortex lattice method computation with Tornado: Wing partition layout | VLM discretization ---------|---------- <img src="./results/mainComputeCoefficients/TornadoAirframe1.png" width="400"> | <img src="./results/mainComputeCoefficients/TornadoAirframe2.png" width="400"> Airfoil JR001 | Example pressure distribution computed by Tornado --------------|--------------------- <img src="./airfoil/JR001.png" width="400"> | <img src="./figures/pressure_distribution_visualization_tornado.png" width="400"> The airfoil JR001 features a planar pressure side which simplifies the build procedure for the wing. The profile was designed to work well with low Reynold's numbers and to provide friendly stall characteristics. It wasn't designed with gliding performance in mind. Further drawings related to the airframe can be found [here](./Tornado/aircraft/ExperimentalCarrier.svg) and [here](./figures/StabilityAxisReferenceForTrimmedGliding.svg). The Tornado definition of the airframe is [here](./Tornado/aircraft). ## <a name="referenceframes"></a>Reference Frames When specifying forces, moments, or angles a body-fixed reference frame is used. The usual convention is shown in the figure below on the left. This is the convention as introduced in [[2]](#caughey) and also as used in Matlab. The Tornado implementation [[1]](#tornado) uses a slightly different reference frame, see below on the right. Standard Body-fixed Reference Frame | Tornado Body-fixed Reference Frame ---------|---------- <img src="./figures/caughey_reference_frame.png" width="400"> | <img src="./figures/tornado_reference_frame.png" width="400"> Standard notation for forces and moments, and linear and rotational velocities in a body-fixed reference frame. The origin is located at the center of gravity (figure reproduced from [[2]](#caughey)) | Reference frame as used in the Tornado VLM implementation. The origin is located at the leading edge of the wing and the x-axis extends aft (figure reproduced from [[1]](#tornado)). ### Stability Axes Another reference frame which is sometimes used is a set of axes for which the x-axis is parallel to the velocity vector for an equilibrium state (e.g. trimmed gliding). Such axes are called _stability axes_. Choosing the principal axes in this way simplifies some equations when computing longitudinal and lateral linear systems from given aerodynamic coefficients (see also [[2]](#caughey) pp. 45). But since the solution implemented here, finds the corresponding LTI systems by linearizing a non-linear model around an equilibrium state, this is not really an advantage. The stability axes reference frame is not used in this implementation. ## <a name="applications"></a>How to Run the Code The codebase and the Simulink models can be used to: 1. Compute aerodynamic properties and [coefficients](#coefficients) using the Tornado VLM implementation. 2. Run the [non-linear flight simulation](#simulation) using previously computed coefficient matrices. 3. Extract the [linear time-invariant systems](#lti) for the trimmed gliding state. ### <a name="coefficients"></a>Compute the Aerodynamic Coefficients Aerodynamic coefficien