course2.md

Exercise Section 2

• (easy way) Download the package husky_highlevel_controller.zip and unzip it to folder ~/catkin_ws/src/.

• Create subscriber to topic /scan with callback method

  • Check topic /scan

    # launch husky_gazebo
    roslaunch husky_gazebo husky_empty_world.launch
    
    # in a new terminal
    rostopic type /scan # get the topic type, which is 'sensor_msgs/LaserScan'

  • Create callback method

    void callback(const sensor_msgs::LaserScan &msg);

  • Create subscriber

    ros::Subscriber sub = nh.subscribe("/scan", 1, callback);

• Add param file & create c++ API to load params

  ros::getParam("param", var);

• Create launch file

  • add node husky_highlevel_controller
  • load param file
  • launch husky_empty_world.launch with argument laser_enabled
  • add RViz

• RViz configuration

  • Set Fixed Frame under the Global Options to odom
  • Add plugin LaserScan and set the Topic as /scan; change the Size to have the best visualization of objects
  • Save the configuration