Welcome to the first lab session of CoTeSys-ROS Fall School!

The challenge of the day will be to get the robot in simulation to navigate to a specific pose. To do that, we will sequence a number of steps:

• tuck the arms
• find the checkerboard on the side of a table (table 1)
• compute the checkerboard's pose
• approach the pose 1m in front of the checkerboard
• rise the robot's spine
• untuck the arms
• approach close to table 1
• and finally, move to the table 2 sideways.

A more complex application would include moving around in a cluttered room and find the checkerboard autonomously.

Prerequisites

Here are some useful tidbits that will help you get around:

• to teleop the robot's base, use:

roslaunch pr2_teleop teleop_keyboard.launch

• to move (Pan/Tilt) the robot's head:

rosrun teleop_head teleop_head_keyboard

• to check the robot's camera view:

rosrun image_view image_view image:=/wide_stereo/left/image_rect

Start Simulation

Bring up the robot, in one terminal:

• http://www.ros.org/wiki/Events/CoTeSys-ROS-School/it#Environment_Setup_on_Your_Work_Machines

rosmake pr2_navigation
export ROBOT_INITIAL_POSE="-x 3 -Y 3.14"
roslaunch ias_gazebo ros_fallschool.launch

Launch a set of tools in another terminal:

rosmake approach_table_tools
roslaunch approach_table_tools tools.launch

Start Rviz

rosrun rviz rviz

Change Fixed Frame "map" to "odom_combined"

Vizualize the following:

• robot model
• grid
• checkboard pose
• approach pose
• camera view

Create Your Package

Create your package, calling it nav_executive, and start developing your own executive:

cd $HOME/ros/sandbox/<group number>

roscreate-pkg nav_executive approach_table_tools actionlib move_base_msgs pr2_common_action_msgs pr2_controllers_msgs drive_base_action

Download the nav_executive.cpp C++ skeleton to start with. It is available by clicking on 'Attachments'. Save the file into the nav_executive package. Add one line to nav_executive/CMakeLists.txt to set it up to compile:

rosbuild_add_executable(nav_executive nav_executive.cpp)

Check that your package builds properly

rosmake nav_executive

Now, open up nav_executive/nav_executive.cpp, look for TODO, and start hacking!

Solution

Our solution is: in executive.cpp. Please click on 'Attachments' to retrieve this file.