3.2) Development Environment

Using the Sample Applications

The simplest (and safest way) to start developing experiments in AERPAW is to use the AERPAW provided sample applications. The page on running sample applications provides details on how to choose between the different options for the three components of the Experimenter code: the radio script, the traffic script and the vehicle control application.

The Experimenter should then carefully follow the plan, installing the client server applications in pairs on the different nodes, as well as edit the parameters of the sample applications as required by the experiment.

Using the OEO Console

The OEO console is the user-facing component that allows an operator to monitor the execution of the current experiment. While in testbed mode, the AERPAW Operators will use the OEO console, but in the development environment the Experimenter also wears an Operator hat and thus can use the OEO Console. To use the OEO Console the Experimenter will have to gain access to the OEO Console container.  To start the OEO Console, after accessing the OEO Console container, type:

cd; ./startOEOConsole.sh

The complete documentation for the OEO Console is available at this page. In what follows, we only provide a minimum subset of commands that allow an experimenter to start and stop an experiment. 

Starting an Experiment

Once the experiment scripts are complete, it is time to test the code. When the experiment is initially deployed in development mode, all the emulation software is ready for the experiment, so the Experimenter should start the experiment. There are at least two ways to start an experiment: manually, or through the OEO.

Manual Start

For starting an experiment manually,  execute :

/root/startexperiment.sh

in each of the E-VMs. If the experiment involves TCP servers (e.g., if using an iperf server with a TCP port), please start the servers first, or, alternatively, appropriately delay the connection attempt from the client (e.g., via sleep).

If the experiment involves a vehicle, then the Experimenter will also take the role of the Safety Pilot and will have to manually arm the Vehicle. This can be done either:

• through the OEO Console by typing all arm or <node_id> arm  (to arm all nodes or a specific node), or

• through the MAVProxy on the OEO Console (available in the mavproxy screen) by typing arm throttle at the MAVProxy prompt, or

• through the QGroundControl connected to the OEO Console (which also has an ARM button on the GUI).

In the field the Safety Pilot will do the equivalent arming by using the remote control associated with the vehicle carrying the portable node.

OEO Start

To start an experiment from the OEO Console, run in the OEO Console:

<node_id> start_experiment

where <node_id> can be all if you want to start the experiment in all nodes, or a number, to start it in a particular node. The effect is the same as in the manual start case (i.e., the OEO system will execute the same /root/start_experiment.sh script as the Experimenter).

In the best case scenario the experiment will run exactly as the Experimenter desired, and the experiment results will then be available in the /root/Results folder for examination. The Experimenter should then assess the resulting logs, and if they are satisfactory for the purpose of the experiment, then the experiment can be then submitted for testbed.

However, in the case the experiment did not complete as desired, then the experiment should be stopped and reset before implementing the corrections.

Stopping an Experiment

In the likely event in which an Experimenter wishes to modify an experiment and re-run it, the entire system should be first reset. Before a reset, the experiment should be first stopped. 

Manual Stop

To stop an experiment manually run:

# /root/stopexperiment.sh

in each of the E-VMs. This should stop all experiment processes in each of the E-VMs (other than bash and the system processes). This can be easily verified either by checking all the screen sessions (see help on screen if needed):

# screen -ls

or by checking the processes:

# ps -aux

OEO Stop

To stop an experiment from the OEO Console, run in the OEO Console:

<node_id> stop_experiment

where <node_id> can be all  if you want to stop the experiment in all nodes, or a node _id to stop it in a particular node. 

Resetting an Experiment

After all experimenter code has been stopped, the vehicle and wireless channel emulators need to be also reset. 

Manual Reset

A manual reset is achieved by running:

/root/reset.sh

on any of the EVMs. This (assuming it completes successfully - please watch the feedback on the console) will reset all the emulation processes on the system and the experimenter can now edit the code and run the experiment again. Each run of the experiment will generate a new log in the /root/Results directory.

OEO Reset

For an OEO Reset, type in the OEO Console:

<node_id> reset_cvm

where <node_id> can be all  if you want to reset the experiment in all nodes, or a node _id to reset it in a particular node.