Dpoom_gazebo

• This reopsitory contains Gazebo simulation of Dpoom, based on turtlebot3 simulation
• Covered urdf, ros topic publication, gazebo
• You can visit our indoor SLAM robot in this page, Project Dpoom

Dpoom in real world	Dpoom in Gazebo

Dependencies

• Ubuntu 18.04
• ROS melodic
• Gazebo 9
• linux-headers-generic
• ros-melodic-turtlebot3-*

Installing

On your catkin_ws/src,

git clone https://github.com/SeunghyunLim/Dpoom_gazebo.git

and 'cd ~/catkin_ws && catkin_make'

Run

for launching Gazebo,

export TURTLEBOT3_MODEL=dpoom
roslaunch dpoom_gazebo dpoom.launch

for teleop keyboard,

export TURTLEBOT3_MODEL=waffle_pi
roslaunch turtlebot3_teleop turtlebot3_teleop_key.launch

for Rviz visualization,

rosrun rviz rviz -d dpoom_rviz.rviz

Topic

• Type : PointCloud2
• ROS topic : /camera/depth/points, /camera/depth/image_raw

Gazebo Environments

• You can select the simulation environment; empty, office, turtlebot3_world.
• Basically, dpoom.launch has empty world for Gazebo. (No obstacles, but just the ground.)

1. Indoor Office by Clearpath Robotics

If you want to simulate in indoor office environment,

• cpr_office_gazebo On your catkin_ws/src,

git clone https://github.com/clearpathrobotics/cpr_gazebo.git

and move cpr_office_gazebo to catkin_ws/src, then 'cd ~/catkin_ws && catkin_make'

• dpoom_office.launch has indoor office environment, which is from Clearpath Robotics. check

2. Turtlebot3_world by ROBOTIS

• dpoom_turtle.launch is based on turtlebot3_world env, which is from ROBOTIS. check

RGB-D Sensor Tilting

• You can tilt the sensor by changing pitch value of the camera_rgb_joint in dpoom.urdf.xacro

  <joint name="camera_rgb_joint" type="fixed">
    <!--You can tilt the sensor by changing the value of pitch
        Ex) <origin xyz="0.003 0.011 0.009" rpy="0 0.3 0"/>-->
    <origin xyz="0.003 0.011 0.009" rpy="0 0 0"/>
    <parent link="camera_link"/>
    <child link="camera_rgb_frame"/>
  </joint>

Default	Tilted by 0.3 rad

RGB-D Sensor Height change

• You can change the sensor height by changing z origin value of the _camera_joint_in dpoom.urdf.xacro

  <joint name="camera_joint" type="fixed">
    <!--You can change the hight of the sensor by changing the value of origin z. 
        Total view-height is sum of this value and "camera_link"'s origin z value, which is 0.013
        Also, for visualization, the change in this part should be considered in "camera_rgb_frame".
        (Original height is 0.12m, so z should be 0.12 - 0.013 = 0.107)

     Ex) <origin xyz="0.073 -0.011 0.107" rpy="0 0 0"/>

     -->
    <origin xyz="0.073 -0.011 0.107" rpy="0 0 0"/>
    <parent link="base_link"/>
    <child link="camera_link"/>
  </joint>

• For proper mesh visualization of the sensor, the change from above should be considered in camera_rgb_frame of dpoom.urdf.xacro

  <link name="camera_rgb_frame">
    <!--Original value of visual origin is xyz="0 0 -0.01"
        if you changed the sensor height in "camera_joint", z should be deducted by the
        height change.

    EX) if you change the sensor height to 13cm(0.13m), which means that you changed 
        "camera_joint" z from 0.107 to 0.117, the visual z origin should be changed 
        from -0.01 to -0.02

    -->
    <visual>
      <origin xyz="0 0 -0.01" rpy="-1.57 0 -1.57"/>
      <geometry>
        <mesh filename="package://dpoom_gazebo/meshes/sensors/d435.dae" scale="1 1 1"/>
      </geometry>
    </visual>
  </link>

• Original sensor height should be fixed to 12cm(from bottom to the center of the sensor).
• The cylinder below has 12cm height, so you can check the sensor height is fixed to 12cm.

Change the Sensor Orientation

• Generally, the depth sensor orientation is x-forward & z-top view.
• However, the libgazebo_ros_openni_kinect.so plugin, which is used in dpoom.gazebo.xacro, has different orientation; z-forward & x-top.
• So, if you want to set the sensor orientation to x-forward & z-top, you need to edit gazebo_ros_openni_kinect.cpp in gazebo_ros_pkgs/gazebo_plugins/src.

From

        *iter_x = depth * tan(yAngle);	 
        *iter_y = depth * tan(pAngle);	
        *iter_z = depth;

To

        *iter_x = depth; 
        *iter_y = -depth * tan(yAngle);
        *iter_z = -depth * tan(pAngle);

References

• https://github.com/ROBOTIS-GIT/turtlebot3_simulations
• http://gazebosim.org/tutorials?tut=ros_depth_camera&cat=connect_ros
• https://github.com/clearpathrobotics/cpr_gazebo
• https://github.com/ros-simulation/gazebo_ros_pkgs