DR mujoco

The documentation page for DR mujoco which simulate differential drive robot for educational purpose.

MuJoCo & ROS 2 Simulator Overview

This simulator is a bridge program designed to connect the advanced physics engine MuJoCo with the ROS 2 robotics framework.

It allows you to test your ROS 2 including control, navigation, and perception algorithms—in a realistic, physics-based environment.

Key Features

Seamless ROS 2 Integration (The Core Feature)

The simulator’s most important feature is its complete integration into the ROS 2 ecosystem.

• Uses Standard Topics:

  • It accepts robot movement commands via the standard /cmd_vel topic, using the geometry_msgs/msg/Twist message type.
  • It publishes the robot’s position and velocity status as an /odom topic, using the nav_msgs/msg/Odometry message type.

• Publishes Sensor Data as ROS 2 Messages:

  • Video from the robot’s camera is published as a sensor_msgs/msg/Image message, which can be viewed in RViz or used as input for computer vision nodes.
  • Wheel encoder tick counts are published as std_msgs/msg/Int32 messages, allowing for more realistic odometry calculation tests.

• Compatible with Existing ROS 2 Tools:

  • You can use the entire ROS 2 ecosystem you’re already familiar with, such as visualizing odometry and sensor data in RViz2 or inspecting the node and topic connections with rqt_graph.

Realistic Physics Simulation

Thanks to the fast and accurate MuJoCo physics engine, the simulator faithfully reproduces contact, friction, and inertia. This helps to reduce the “Sim-to-Real Gap,” making the transition from simulation to a physical robot smoother.

Customizable Robot Models

The robot in the simulation is defined using MuJoCo’s XML format, giving you the freedom to design and test your own creations. You can quickly modify wheel sizes, body mass, sensor placements, and more to prototype different robot designs.

How It Works

This simulator acts as a bidirectional “translator” between your ROS 2 nodes and the MuJoCo engine.

 [Your ROS 2 Node]   <-- ROS 2 Topics -->   [This Simulator]   <-- MuJoCo API -->   [MuJoCo Physics Engine]
(e.g., Teleop Node)    (/cmd_vel, /odom)     (ROS 2 <=> MuJoCo)