SE3 Controller and EasySim Setup

Overview

This guide explains how to set up and launch the SE3 controller for multicopter takeoff, control the multicopter to follow either a circular or a trajectory path, and receive image messages from Unreal Engine (UE) via EasySim and publish them to ROS.

中文README

https://github.com/9woods123/cmd2airsim/blob/master/README_ch.md

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Setup Instructions

0. Clone Repositories and Build the Workspace

First, clone the necessary packages into your catkin_ws/src directory:

cd ~/catkin_ws/src
git clone https://github.com/9woods123/cmd2airsim.git

Then, go back to the workspace root and build the project:

cd ~/catkin_ws
catkin_make
source devel/setup.bash

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0.1 Adjust Network Buffer Size

Before launching the image streaming node, increase the system network buffer size to avoid dropped image messages:

sudo sysctl -w net.core.rmem_default=8388608
sudo sysctl -w net.core.rmem_max=8388608

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1. Start Unreal Engine (UE) Simulation

Make sure the UE simulation environment is up and running before starting the SE3 controller.

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2. Launch SE3 Controller for Takeoff

In a terminal, launch the SE3 controller to initiate multicopter takeoff:

roslaunch se3controller se3controller.launch

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3. Control the Multicopter (Choose One)

After takeoff, you can choose one of the following flight modes:

Option 1: Follow a Circular Path

roslaunch se3controller flying_example.launch

Open RViz and set the Fixed Frame to world_enu:

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Option 2: Follow a Predefined Trajectory

roslaunch se3controller flying_traj_example.launch

We provide a default RViz configuration for this example. You can refer to it to set the Fixed Frame, image topic, and odometry topic:

💡 Only one control mode should be launched at a time.

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4. Launch EasySim ROS Wrapper to Receive Image Messages

To receive and publish image messages from Unreal Engine, launch the EasySim ROS wrapper:

roslaunch easysim_ros_wrapper img_ros_node.launch

💡 If you want to test image reception separately (without the SE3 controller), this node can be launched independently to verify communication with UE.

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Troubleshooting

• ✅ Ensure the UE environment is running and configured to stream image data correctly.
• ✅ Confirm that the network buffer size was increased (step 0.1).
• ✅ Use source devel/setup.bash in every terminal before launching ROS nodes.
• ✅ If catkin_make fails, check for missing dependencies or incorrect package structure.

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