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).

1. From the shell, start roscore:

   roscore

2. Start pr2_gazebo:

   roslaunch pr2_gazebo pr2_empty_world.launch

3. Start additional components for (fake) localization:

   roslaunch pr2_nav_pcontroller nav_pcontroller.launch

   1. IMPORTANT: Set the parameter (under <rosparam>) for “global_frame” as follows in the launch file:

      global_frame: odom_combined

      For this, it might be better to just copy the launch file and change this in your local version.

   2. Remark: On the “real” robot, this would be:

      roslaunch ias_pr2_2dnav pr2_2dnav.launch

      which should launch all the necessary parts.

4. Start emacs and run the SLIME REPL for ROS:

   M-x slime-ros

5. From within emacs, load the PR2 navigation process module:

   ,ros-load-system pr2-navigation-process-module

6. Switch to the nav process module package:

   ,!p

   pr2-navigation-process-module

7. Run the ROS node:

   (startup-ros)

8. “Fake” the localization (since no mapping server is present):

   (setf designators-ros:*fixed-frame* "odom_combined")

9. Initialize the nav process module: <code>(init-pr2-navigation-process-module)</code> Nope, this is done automatically during the loading of this system.
10. Send a navigation action to position (x, y) with rotation (qz):

    (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))))))

11. Watch it move in gazebo ;)!