Visualize VTOL Flight Mission Over Urban Environment

Step 4 of 5 in Design and Tune Controller for VTOL UAV

This example shows how to visualize a vertical takeoff and landing (VTOL) aircraft in Unreal Engine® while flying a mission within an urban environment. In the previous examples, the control design for a tiltrotor VTOL has been previously tuned through hover, transition and fixed wing flight. This example leverages the custom actor workflow in UAV Toolbox™ to visualize aircraft performance in a photorealistic environment.

Prerequisites

Download and install UAV Toolbox Interface for Unreal Engine Projects. For more information about installing and setting up the UAV Toolbox Interface, see Install Support Package for Customizing Scenes.

This example uses a 3D Game Asset Urban Air Mobilty Vehicle dataset, which contains a fbx file of a VTOL UAV and is approximately 6 MB in size. Download the VTOLAsset ZIP file from the MathWorks website, then unzip the file.

zipFile = matlab.internal.examples.downloadSupportFile("uav","data/VTOLAsset.zip");
filepath = fileparts(zipFile);
dataFolder = fullfile(filepath,'VTOLAsset');
unzip(zipFile,dataFolder)

Getting Started

Open the VTOL MATLAB project.

prj = openProject("VTOLApp/VTOLRefApp.prj");

This example uses MATLAB Project shortcuts. Use the highlighted project shortcuts for setting up the model and the photrealistic simulation. You can use the other project shortcuts for tuning the hover, fixed-wing, transition configurations. To see these shortcuts, you must open and view the Project editor tab.

Click Getting Started in Project Shortcuts tab to set up the aircraft plant model and base controller. You can also set up the model and controller programmatically by using the setupPlant helper function.

setupPlant;

Initialized VTOL model.
Enabled hover configuration.
Enabled hover guidance mission.

Open the Visualization subsystem of the VTOLTiltrotor model.

load_system("VTOLTiltrotor")
open_system("VTOLTiltrotor/Visualization")

Set Up Unreal Visualization

Click Photorealistic Visualization in the Project Shortcuts tab to configure the VTOLTiltrotor Simulink® model to use the Unreal Engine to simulate the VTOL mission. This shortcut also configures the VTOL aircraft with some predefined control gains and a guidance mission. You can also configure the aircraft programmatically by using the setupPlant helper function.

setupCityMission;

Initialized city mission.

Point Model to Unreal Engine Project

Open the Photorealistic subsystem in the Visualization subsystem.

open_system("VTOLTiltrotor/Visualization/Photorealistic")

Open the Simulation 3D Scene Configuration block mask and set the Scene source parameter to Unreal Editor and supply the path to the AutoVrtlEnv Unreal Engine project on your system. If you do not have the AutoVrtlEnv file, you must download the UAV Toolbox Interface for Unreal Engine Projects support package to complete this step. The installation and set up process for the UAV Toolbox Interface for Unreal Engine Projects includes setting up the AutoVrtlEnv file.

Import VTOL Vehicle into Unreal Engine Scene

To use the VTOL asset in Unreal Engine scenes, you must import the asset into Unreal Engine. After importing the asset, you do not need to import the VTOL asset again for future use in Unreal Engine.

Launch Unreal Editor

In the Photorealistic subsystem, click Open Unreal Editor in the Simulation 3D Scene Configuration block to launch Unreal Editor from MATLAB.

Import VTOL Asset into Unreal Engine Scene.

Click Add/Import in Unreal Editor and select New Folder from the context menu. Create a folder called EVTOL in the Content Browser pane and then open the EVTOL folder.

Click Add/Import again and then select Import to Game/EVTOL. Navigate to the folder that the VTOLAsset is saved in and select the VTOLAsset file to open the FBX Import Options dialog box.

To select a skeleton mesh, you must first open the Skeleton drop down list and click the View Options drop down. Then select both Show Engine Content and Show Plugin Content to add the UAV_Skeleton mesh option to the Skeleton drop down list. Then select UAV_Skeleton.

Set the Import Uniform Scale parameter to 0.25 in FBX Import Options to scale the VTOL asset to a smaller, more realistic size.

To finish the import of asset, click Import in Unreal Editor.

Customize VTOL Asset

Double click to select VTOL Asset in the Content Browser pane to open the Asset Details window.

Now you need to select the element of the VTOL skeletal mesh that to be the main body of the vehicle and name it VehicleBody. For this VTOL asset, select Element 1, the fuselage, as the main body. You can verify that Element 1 is the fuselage by selecting isolate to see which body the element is representing. Set the Slot Name of Element 1 to VehicleBody. Then save the VTOL asset

Now right-click the VTOLAsset skeletal mesh object in Content Browser pane and click Copy Reference to copy the reference path to this asset.

In the Simulation 3D UAV Vehicle block of the Photorealistic subsystem, set the Type parameter to Custom and then set the Path to custom mesh parameter to the reference path.

Visualize VTOL Mission in Urban City Mission

Navigate to Maps in Content Browser and click on USCityBlock to load the US City Block scene.

Run the VTOLTiltrotor Simulink Model.

sim("VTOLTiltrotor");

When Simulink sits at initializing, click Play in Unreal Editor. Zoom out using mouse scroll to visualize UAV flying a mission over the city. You can optionally enable Pacing in the Run > Simulation Pacing tab within Simulink to change the simulation speed so that the simulation runs at real time for smoother visualization.

Summary

In this example, you visualized a VTOL aircraft mission in 3-D simulation environment. Next, learn how to customize the VTOL controller.