TurtleBot4 Simulator

⚠️ Note: This repository is a fork of the official TurtleBot4 Simulator. For the latest updates, features, and official documentation, please refer to the upstream repository.

This fork is mainly was used for:

• Debugging purposes
• Team testing with simulation environments

1. Installation & Environment Setup

System Requirements

• OS: Ubuntu 22.04 or later (tested up to 24.04)
• ROS 2: Recommended: Jazzy (also tested: Humble)
• GPU: Strongly recommended for real-time simulation (e.g., NVIDIA or equivalent)
• Gazebo: Ignition Gazebo (Fortress or newer)

Setup Steps

1. Clone & Build the Simulator:

• mkdir -p ~/turtlebot4_ws/src cd ~/turtlebot4_ws/src git clone https://github.com/turtlebot/turtlebot4_simulator.git cd .. rosdep install --from-paths src --ignore-src -r -y colcon build --symlink-install
• Source the Workspace:
• source ~/turtlebot4_ws/install/setup.bash
• Launch Simulation:

1. ros2 launch turtlebot4_gazebo sim.launch.py

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2. SLAM & Navigation (Nav2)

SLAM

To enable SLAM in the simulation:

ros2 launch turtlebot4_gz_bringup turtlebot4_gz.launch.py slam:=true

If RViz is needed:

ros2 launch turtlebot4_gz_bringup turtlebot4_gz.launch.py slam:=true rviz:=true

Navigation (Nav2)

In some cases, the Nav2 stack does not auto-launch properly. To fix this:

Manual Nav2 Launch

ros2 launch navigation2_bringup navigation_launch.py \
  use_sim_time:=true \
  param_file:=/opt/turtlebot4/share/turtlebot4/config/navigation.yaml

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3. Troubleshooting Common Errors

Error: start_motor or start_camera service unavailable

• These services are not simulated or depend on missing plugins.
• You can safely ignore them for SLAM testing.

Lidar / tf timestamp errors in SLAM

• Root cause: GPU rendering not enabled.

• Fix: Force ogre2 rendering engine:

• ros2 launch turtlebot4_gazebo sim.launch.py --render-engine ogre2

Simulation too slow (RTF < 0.3)

• Use a dedicated GPU or adjust physics/rendering settings (see next section).

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4. Performance Optimization

Real-Time Factor (RTF)

Target: RTF ≥ 0.6 for stable SLAM/Nav2

GPU Acceleration (Steam Deck or PC w/ NVIDIA)

__NV_PRIME_RENDER_OFFLOAD=1 \
__GLX_VENDOR_LIBRARY_NAME=nvidia \
ros2 launch turtlebot4_gz_bringup turtlebot4_gz.launch.py \
  slam:=true nav2:=true rviz:=true

Simulation Optimization Techniques

• Remove unnecessary models from the world.

• Disable shadows and the skybox in Gazebo.

• Lower camera resolution and FPS:

• 320 240 10

• Reduce lidar frequency to 5-10Hz (but not too low — affects Nav2).

Physics Engine Tweaks

Add to world.sdf:

<physics name="default_physics" type="ode">
  <max_step_size>0.01</max_step_size>
  <real_time_update_rate>100</real_time_update_rate>
  <real_time_factor>1.0</real_time_factor>
</physics>