===== Sending poses to PR2 in gazebo using action designators =====

This step-by-step explanation shows how to get the PR2 gazebo simulation
up and running and how to execute simple translation/rotation commands
using high level components (i.e. action designators).

  - From the shell, start roscore: <code>roscore</code>
  - Start pr2_gazebo: <code>roslaunch pr2_gazebo pr2_empty_world.launch</code>
  - Start additional components for (fake) localization: <code>roslaunch pr2_nav_pcontroller nav_pcontroller.launch</code>
    - **IMPORTANT:** Set the parameter (under <rosparam>) for "global_frame" as follows in the launch file: <code>global_frame: odom_combined</code> For this, it might be better to just copy the launch file and change this in your local version.
    - **Remark:** On the "real" robot, this would be: <code>roslaunch ias_pr2_2dnav pr2_2dnav.launch</code> which should launch all the necessary parts.
  - Start emacs and run the SLIME REPL for ROS: <code>M-x slime-ros</code>
  - From within emacs, load the PR2 navigation process module: <code>,ros-load-system pr2-navigation-process-module</code>
  - Switch to the nav process module package:<code>,!p</code><code>pr2-navigation-process-module</code>
  - Run the ROS node: <code>(startup-ros)</code>
  - "Fake" the localization (since no mapping server is present): <code>(setf designators-ros:*fixed-frame* "odom_combined")</code>
  - <del>Initialize the nav process module: <code>(init-pr2-navigation-process-module)</code></del> Nope, this is done automatically during the loading of this system.
  - Send a navigation action to position (x, y) with rotation (qz): <code>(call-nav-action *navp-client*
                      (make-designator
                        'desig-props:location
                        `((desig-props:pose ,(tf:make-pose-stamped
                                                "/base_footprint"
                                                0.0
                                                (tf:make-3d-vector x y 0)
                                                (tf:make-quaternion 0 0 qz 1))))))</code>
  - Watch it move in gazebo ;)!