nuturtle_description

Package: nuturtle_description

Author: Maurice Rahme

Package Summary

This package houses the description of a differential drive robot with a caster wheel for support. The robot is viewable in RViz using view_diff_drive.launch.

Launch Instructions

Run roslaunch nuturtle_description view_diff_drive.launch --ros-args to view any optional arguments and their instructions.

Run roslaunch nuturtle_description view_diff_drive.launch to view the differential drive robot in RViz alongside the joint state publisher GUI, which allows you to control the rear wheel joint angles.

Run roslaunch nuturtle_description view_diff_drive.launch jsp_gui:=0 to view the robot without the GUI.

diff_params.yaml

This file loads the differential drive robot's parameters into the parameter server.

• wheel_width: the width of the rear wheels.
• wheel_radius: the radius of the rear wheels.
• wheel_base: the distance betweem the centres of the wheels.
• chassis_length: the length of the main chassis link.
• chassis_thickness: the thickness of the plate that forms the chassis.

diff_drive_macro.xacro

This file contains macros which describe generic bodies and joints required for the robot for modularity and brevity.

• xacro:macro name="wheel_joint": describes a wheel joint used for the wheels.
• xacro:macro name="frame_joint": describes a joint which holds the base_link frame to the base_footprint frame.
• xacro:macro name="r_box": describes a generic rectangular prism, used for the chassis.
• xacro:macro name="r_cyl": describes generic cylindres, used for the rear wheels.
• xacro:macro name="r_sph": describes a generic sphere, used for the ball caster support.

diff_drive.urdf.xacro

This file loads diff_drive_macro.xacro as well as diff_params.yaml to create a URDF description of the robot modularly.

ddrive_bl.rviz

This RViz config file saves a view which hides all frames except base_link and rl_wheel.

ddrive.rviz

This RViz config file shows the differential drive robot with all its frames.

view_diff_drive.launch

This launchfile starts by loading the robot's description through diff_drive.urdf.xacro, alongside the robot and joint state publishers, which are necessary to display the robot in RViz. It has an optional parameter use_jsp_gui that defaults to true to show the joint state publisher GUI, which allows the user to control the robot's wheel joint angles. Next, it loads the paramters from diff_params.yaml into the parameter server, and calls the RViz node along with the ddrive_bl.rviz config file to show the robot with only its base_link and rl_wheel frames visible.