Simulation
==========

.. image:: media/gifs/b1_gazebo.gif
   :width: 100%
   :align: center

Unitree B1 supports two different development environment Gazebo
with which a virtual robot in the simulation can be programmed
for testing in real world virtual evironments and is ideal for low-level
gait driver development. Gazebo drivers are simulated with a fake control node 
and visualization tool RViz is used. The current implementation for Gazebo is working 
using the opensource `CHAMP <https://github.com/chvmp/champ>`__ drivers.

Gazebo support different sensors like IMUs, lidars, cameras and
many more. With these simulators and sensors autonomous navigation, slam
and other functionalities can be tested.

In this instruction, Gazebo will be introduced which is most widely used
among ROS developers.

Gazebo Tutorials: http://gazebosim.org/tutorials

Gazebo
------

.. qre_B1_gazebo & qre_controller
.. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

.. `qre_B1_gazebo` package contains the Gazebo simulation for the B1 robot. The robot can be teleoperated and can be used further for slam and autonomous navigation. This package is dependent upon `qre_controller` which contains several low level robot controllers `state_estimator, quadruped_controller` and `contact_sensor`.

.. To launch `Gazebo` run the following command:

.. .. code:: bash

..     roslaunch qre_B1_gazebo gazebo.launch

.. This launch file runs all the necessary controllers and accept commands in `cmd_vel(geometry_msgs/Twist)`. The same package `qre_controller` can be used to verify the robot movements in `RVIZ`. To do so run the following command:

.. .. code:: bash

..     roslaunch qre_B1_description bringup.launch rviz:=true ll_control:=true


.. Now by running any `teleop node` the robot can be controlled.

.. .. figure:: media/mbs_gazebo.png
..     :width: 100%
..     :align: center
..     :alt: QuadrupedRoboticsGazebo