Field Operation Guide

Prior to placing the robot in the water, perform one final check to ensure the robot is set up in the configuration you would like (ballasted correctly, tethered vs. untethered) and that it is sealed. Ensure that an operator is with the robot at all times and that the operator has a power switch for the robot.

Notes for Tethered Operation

Connect the tether to the robot. Spool out the tether, giving the robot enough tether to move around freely, but not so much that it will become entangled in itself and cause knotting issues. Be careful not to step on the tether during operation. One person should be in the water with LoCO at all times to monitor the AUV and perform an emergency power off if necessary. If operating in a lake, river, or ocean, ensure you have someone manning the tether at all times. This person has to have two hands on the tether and should be constantly monitoring how much tether is available for the robot, adjusting as necessary, and should be monitoring any knots that occur and where the tether is in relation to human operators in the water. Having a designated person manning the tether is less critical in pool operations since currents will not be manipulating the tether, but still be careful to keep an eye on it.

Teleoperation

To use remote control, make sure that your laptop is connected via Ethernet to the robot, then connect a wired Logitech controller to your laptop. Simply run roslaunch loco_teleop joy_teleop.launch, and you will be able to use the controller.

This launch file runs both the joy_node which allows the controller's messages to be published into ROS and the pycontroller.py from the loco_teleop package which turns the joystick positions into loco_pilot/Command messages. The Pixhawk must be armed and mavros must be running for teleop to work, so check that the big light on the Pixhawk is solid blue if you're having issues.

Control scheme:

• Right analog stick: Forward is forward throttle, backward is reverse throttle.
• Left analog stick: Forward is up, backward is down.
• Left analog stick: Left is turn left, right is turn right.

Notes for Tetherless Operation

Make sure an operator is with the robot at all times. If operating in a lake, river, or ocean it is easiest to have a handful of personnel in the water to monitor the robot. With the software packages available, commanding the robot with AR tags or hand signals is possible.

Drowning the Robot and Starting Operations

Place LoCO in the water and submerge it. Carefully brush away any air bubbles that come with placing the robot in the water. Rotate the robot entirely, turning it over in the water. Watch for any additional bubbles that form on the surface of the robot or any streams of air coming from the robot. If this is the case, remove the robot from the water as soon as possible since air bubbles are a strong indicator of a leak that could compromise the AUV. Once the robot has been looked over for bubbles and leaks, Power the robot on using the magnetic switch. Once the lights within the tubes are visible and the center light of the Pixhawk is solid blue, the robot is ready to perform operations. Proceed with your tests and experiments.