jokla / didi_challenge_ros

Roslaunch to visualize a rosbag file from Udacity (DiDi Challenge)

DiDi Challenge

Here you can find more info about the challenge. In this repository you will find a simple launch file to play a rosbag file and visualize the result in RViz.

Instructions:

Install ROS:

Follow instructions you find in this page.

• Point 1.2 : choose instructions for your version of Ubuntu.

• Point 1.4 : Desktop-Full Install: (Recommended).

• When you configure the ROS Environment, choose catkin.

• Complete the tutorial page. It is mandatory to follow the tutorial number 1 "Installing and Configuring Your ROS Environment".

Now we have installed ROS and we have created our workspace.

• Open the file bashrc: gedit ~/.bashrc if you want to avoid to type the following command every time, add in the end of the file :

  export ROS_PACKAGE_PATH=${ROS_PACKAGE_PATH}:/path_to_catkin_ws/catkin_ws/src
  source /opt/ros/indigo/setup.bash
  source /path_to_catkin_ws/catkin_ws/devel/setup.bash
  

Remember to change /path_to_catkin_ws with your path and change indigo if you are using another version of ROS.

Close the terminal an open a new one.

I used Ubuntu 14.04 and ROS Indigo.

Download dataset:

• Download the 32GB dataset from here.

Clone the repo:

• Go in the src folder of your catkin workspace in catkin_ws/src via terminal
• Clone the repository typing:
  $ git clone https://github.com/jokla/didi_challenge_ros.git
• Go in your catkin_ws and do catkin_make:
  $ cd ~/catkin_ws
$ catkin_make
• Now source the setup.bash;
  $ source ~/catkin_ws/devel/setup.bash
• Check if ROS is able to find the package:
  $ roscd didi_challenge_ros

Visualize Lidar, camera and Laser using RViz:

Launch display_rosbag_rviz.launch setting the path to the rosbag file you want to use:

$ roslaunch didi_challenge_ros display_rosbag_rviz.launch rosbag_file:=CHANGE_WITH_PATH/approach_1.bag

Explanation launch file

The launch file display_rosbag_rviz.launch is doing the following:

• Playing in loop the rosbag file

<arg name="rosbag_file" default="my_file_1" />
<node pkg="rosbag" type="play" name="player" output="screen" args="-l $(arg rosbag_file) "/>

• Publishing the transformation between the link 'base_link' and 'velodyne'

<node pkg="tf2_ros" type="static_transform_publisher" name="link1_broadcaster" args="1.9 0 1.6 0 0 0 1 base_link velodyne" />

• Opening RViz with the setting file 'display.rviz'

<node name="rviz" pkg="rviz" type="rviz" args="-d $(find didi_challenge_ros)/launch/display.rviz" />