Differential Drive Gazebo Simulator for ROS2 Humble

This repository contains the code and configuration files to launch a GoBilda differential drive robot simulation in Gazebo with ROS2 Humble. The simulation runs inside a Docker container for a consistent and reproducible environment.

Pre-requisites

• Docker installed and configured on your system

Setup Guide & Quick Start Guide

Follow these steps to get the simulator running

1. Clone this repository

Start by cloning this repository to your local machine:

git clone https://github.com/ambulantelab/gobilda_sim.git
cd gobilda_sim

2. Edit the Makefile to properly pull the correct docker image from DockerHub

• The correct Docker image must be selected for your computer's architecture (x86 for Intel/AMD PCs, ARM for Apple Silicon Macs).
• Find and modify the IMAGE_NAME line:
• For x86 PCs (Intel/AMD): Use x86.
• For ARM PCs (Apple M1/M2): Use arm.

3. Create the Docker Network

Run the following command to create a shared network that allows the simulator and visualization tools to communicate. You only need to do this once.

docker network create ros

4. Start the Web Visualizer (ncVNC)

This command starts a web-based visualizer. You will use your browser to view the Gazebo simulation and RViz.

make novnc

After running this, open your web browser and go to: http://localhost:8080/vnc.html. You should see a desktop environment.

5. Run the simulation image and mount your local copy of this repository

Open a new terminal window in the gobilda_sim directory. Run the following command to start the simulator container and mount your local code into it.

make bash NAME=sim_test

This will drop you into a bash shell inside the running Docker container. Your terminal prompt will change to something like root@container_id:/workspace#.

If you get errors about not having the image locally, you can run the following command to manually pull the image from DockerHub (remember your platform):

docker pull ambulantelab/cpe416:lab4-arm

6. Build and Source the Workspace (Inside the Container)

From the bash shell inside your container, run:

colcon build --symlink-install
source install/setup.bash

7. Launch the Simulation (Inside the Container)

Finally, launch the main simulation launch file:

ros2 launch ros_gz_example_bringup diff_drive.launch.py

You should now see the Gazebo simulation window open in the noVNC browser tab you opened in Step 4, and the robot will be spawned. Finally, you should press play in the Gazebo simulator to start the simulation. After, you should see the topics and robot model in RViz.