Tutorials/CloudSim/1.2/field computer

Introduction === This tutorial covers connecting to the field computer of a trio constellation to perform system updates and run software that interacts with the simulator.

Prerequisites === This tutorial assumes: You have started a VPC trio constellation in the Cloud with Gazebo running, that you have a Virtual Private Network running. See the related tutorials:
 * Start a VPC trio constellation
 * Connecting to a cloud simulation with a Virtual Private Network

Anatomy of the Field Computer ===

The field computer is provisioned for you in a minimal state. It comes loaded with:
 * Unbuntu Precise 12.04
 * ROS fuerte
 * The latest gazebo, drcsim and cloudsim-client-tools packages from OSRF.
 * A `cloudsim/ros.bash` script to configure the simulator machine as the ROS and Gazebo master
 * A routing script `/etc/init.d/vpcroute` to ensure communication between constellation machines across reboots.

It is anticipated that once the constellation is online, you will need
 * update some packages
 * install new software
 * connect to the simulation

Update the software on the field computer ===

The way to perform this task is via scp and ssh (see section below). It is recommended to use scripts (and configuration management tools) to automate the process of updating the field computer from its initial state. Just be mindful of the routing configuration should you decide to install a new OS on that machine.

Start the Gazebo simulator on a VPC trio constellation ===
 * Start a VPC trio constellation

Start the Virtual Private Network ===
 * Connecting to a cloud simulation with a Virtual Private Network

Connect to the field computer via ssh ===

Download the field computer's keys and execute the ssh script to log on to the field computer:

unzip ~/Downloads/field_computer_cxe488142c.zip field_computer_cxe488142c/robot_ssh.bash

Connect to the simulation from the field computer ===

Once you are logged in the field computer, source the provided ros.bash file that sets your ROS environment and sets the simulator machine as the ROS master:

. cloudsim/ros.bash

To verify that the field computer is connected to the simulation run the `rostopic` command:

rostopic list

You should see the list of ROS topics that are published in the simulation, like this:

... /multisense_sl/camera/stereo_proc_rectify_color_right/parameter_updates /multisense_sl/camera/stereo_proc_rectify_mono_left/parameter_descriptions /multisense_sl/camera/stereo_proc_rectify_mono_left/parameter_updates /multisense_sl/camera/stereo_proc_rectify_mono_right/parameter_descriptions /multisense_sl/camera/stereo_proc_rectify_mono_right/parameter_updates /multisense_sl/imu /multisense_sl/joint_states /multisense_sl/laser/scan /multisense_sl/set_spindle_speed /rosout /rosout_agg /tf /tf2_buffer_server/cancel /tf2_buffer_server/feedback /tf2_buffer_server/goal /tf2_buffer_server/result /tf2_buffer_server/status /tf_static