Create a maritime vehicle

Overview

This tutorial goes through the process of designing a maritime model to be used in Gazebo. Our basic model will be a turtle. First, we'll start simple and will add more features as we progress in the tutorials.

Related tutorials

https://gazebosim.org/docs/harmonic/building_robot

Design a basic SDF model

Create a workspace to store your brand new model named my_turtle.

mkdir -p ~/gazebo_maritime/models/my_turtle && cd ~/gazebo_maritime/models/my_turtle

Each model must have a model.config file in the model's root directory that contains meta information about the model. Create a model.config file:

<?xml version="1.0"?>
<model>
  <name>my_turtle</name>
  <version>1.0</version>
  <sdf version="1.6">model.sdf</sdf>
 
  <author>
    <name>Carlos Agüero</name>
    <email>caguero@openrobotics.org</email>
  </author>
 
  <description>
    My 3D turtle.
  </description>
</model>

You can find a description of the allowed elements in model.config in this Gazebo Classic tutorial.

Create a model.sdf file that contains the Simulator Description Format of the model. You can find more information on the SDF website.

<?xml version="1.0"?>
<sdf version="1.6">
  <model name="my_turtle">
    <static>true</static>
    <link name='base_link'>
 
      <inertial>
        <pose>0 0 0 0 0 0</pose>
        <mass>10</mass>
        <inertia>
          <ixx>0.35032999999999995</ixx>
          <ixy>0</ixy>
          <ixz>0</ixz>
          <iyy>0.35032999999999995</iyy>
          <iyz>0</iyz>
          <izz>0.61250000000000006</izz>
        </inertia>
      </inertial>
 
      <collision name="collision">
        <geometry>
          <box>
            <size>1 1 0.009948450858321252</size>
          </box>
        </geometry>
      </collision>
 
      <visual name="visual">
        <pose>0.08 0 0.05 0 0 0</pose>
        <geometry>
          <cylinder>
            <radius>0.35</radius>
            <length>0.23</length>
          </cylinder>
        </geometry>
      </visual>
    </link>
  </model>
</sdf>

The model.sdf file contains the necessary tags to instantiate a very minimal model named my_turtle using SDF version 1.6.

Load your model in Gazebo

Launch Gazebo and load our model:

gz sim ~/gazebo_maritime/models/my_turtle/model.sdf

You should see your model visualized as a cylinder and the Gazebo Entity Tree should capture its structure.