DIY Submarine Gets Into Deep Trouble

Aerial drones are getting to be a common sight, but it is still a rare occasion when one sees an autonomous submarine floating by. As such, it is somewhat surprising to see a DIY autonomous submarine project, like the one by the CPSdrone team that we recently reported on. They have been hard at work on all of the details that go into building an underwater vehicle, but since they are in uncharted waters (literally), they are taking things one small step at a time.

The ultimate goal is for the sub to travel at the bottom of the ocean where it can explore shipwrecks and other interesting underwater features, but so far it has only dipped its toes in the water. In their latest video, the team detailed some upgrades they have made to their vehicle to bring it another step closer to the target. For starters, they have replaced the existing fin-based steering module with a simpler and more effective propeller-driven steering mechanism. They also added a buoy containing a GPS receiver that is tethered to the vehicle to help with navigation.

With these enhancements, CPSdrone felt comfortable releasing their sub into a lengthy system of canals and lakes for the next test. They were not quite ready to cut it completely loose, however — they followed along in a kayak in case the vehicle got into trouble.

Staying nearby turned out to be a good move. After a short time, the sub stopped moving and surfaced. After a quick software update to the navigation system, the vehicle was launched again and performed much better. But at the half-way point, they ran into much more serious trouble. In a narrow canal, the sub lost its way and crashed into a wall, damaging a propeller.

That ended the test for the day, but after 3D-printing some replacement parts, the vehicle was back in action the next day. It was launched from the point of the failure once again — or at least that was the plan. The sub was intent on going off course, and after some investigation it turned out to be a problem with the compass.

The team further found that their aerial drone’s compass was having calibration issues at the same location. Unable to get around this, they simply went down the canal a ways and launched the vehicle again, but this time successfully. They were unsure what happened, which is not exactly a satisfying result, but they are planning to add a backup compass to a future revision of the vehicle in the hope that it will help to avoid this type of problem again.

From that point on, it was all smooth sailing. The sub made it to the destination completely unaided. This test may not have been perfect, but a lot of valuable information was collected. With a few more tweaks, the team plans to free their sub from the buoy and take it to the bottom of the ocean. Be sure to stay tuned for updates.