Imagine skimming just above a lake bottom, exploring underwater terrain that’s never been seen by anyone before, all without leaving the safety and comfort of a powerboat.  Virtual reality goggles give you the feeling of being right on board the drone and the joy stick control puts you in the pilot seat.  As your powerboat pulls it along faster then a diver can swim, it records the changing water depth coming up and displays it on the VR screen.  All the action is recorded on an SD card in 360 video along with latitude and longitude so you will know the exact location of any treasures you find.

I came up with the idea for a towable underwater drone while seaching a lake bottom for an outboard motor that had gotten loose and fell off the back of a fishing boat.  The search area turned out to be much larger than anticipated.  Although the water was just 15 feet deep, visability was only 8 feet and the bottom could not be seen from the surface.  After a half hour of searching and my air tank half empty I had an idea.  To cover more area, instead of swimming, have them tow me with a rope behind the powerboat.  It worked so well I thought about it more and came up with the idea for a towable underwater drone.

Unfortunatly towable underwater drones don’t exist yet but could be built with today’s current technology.  Heres the rest of my idea with more details.

THE BASE:  The base unit contains the complete system that quickley connects to a permanently mounted bracket at the stern (port or starboard side) of any powerboat.  A storage compartment on the base contains VR goggles, a wired joy stick, and a cable with alligator clips that connect to the tow boats 12V battery for power.  A small rechargable 12V gel cell battery is also contained in the base for emergency power.  On the back of the base a depth finder is mounted at the end of a telescopic shaft that extends into the water.  The base also contains a gps, computer, electronics, and reel of 200 feet of tow cable that also provides power and data transfer for the drone.  The boom keeps the drone and tow cable clear of the boats motor and propeller.

HOW IT WORKS:  The pilot attaches the wired joystick control to any smooth surface by suction cups in a position thats comfortable to use and turns on the main power.  When the boat is in the desired area the pilot puts on the VR goggles connecting him to to the drone’s 360 degree camera via blue tooth conection with the base.

As soon as the drone is lowered by its cable via the joy stick middle finger switch, the camera and headlights turn on, video from the drones camera is sent to the VR goggles video screen, and recording begins on the memory card.  The 360 degree camera and VR goggles give the pilot the ability to look left, right, up and down in real time.  With the boat moving forward slowly, the pilot pulls back on the joy stick (to keep the drone on the surface) and continues to unwind tow cable until the drone contacts the water.  With the drone skiping across the surface the pilot continues to let out aproximately 100 feet of cable.   The base computer continuously records the depth of the water between the power boat and the drone and displays it as a “bottom profile line” on the VR goggle display.  This allows the pilot to know the depth of water where the drone is as well as any obstacles or depth changes 100 feet ahead.

The digital proportional joy stick is conected to the drone through the base computer to create a fly-by-wire control system.  Two servos in the drone control up/down and left/right respectively to create the following functions:

• Pull back to go up
• Push forward to go down
• Move left to go left
• Move right to go right

Information from the “water speed sensor” on the drone is sent into the base computer to determine the ratio of movement of the drone’s control surfaces to joystick input.  The computer will also override joystick input should depth sensors on the tow boat or drone indicate imminent impact with the bottom.  These 2 fly-by-wire features allow for both safety and ease of control by new/inexperienced pilots.

Video is sent from the drone’s low light 360 degree camera to the base computer through the tow cable.   The following overlay of information is added to the video before being sent by blue tooth to VR 360 degree  goggles:

• “Drone Depth” from depth guage on drone
• “Bottom Depth” from depth finder on drone
• “Speed of Tow Boat” determined by base’s GPS
• A “Bottom Profile Line“, created from the base’s depth finder data, the line shows a profile of the bottom between the drone and the tow boat. This aids to warn the pilot in murky water and high speeds of sudden depth changes and obstacles coming up.  It also shows the drone’s position in relation to the bottom.
• “Distance to Tow Boat” (same as the length of bottom profile line being displayed).
• “Latitude and Longitude” of the drone.  The base computer uses the GPS of the base unit and calculates direction of the tow boat, length of tow rope, depth of drone and left/right angle of the tow cable leaving base unit to get the actual latitude and longitude of the drone itself.
• Current “Date and Time” with seconds
• “REC” indicating video is being recorded
• The following warning messages are displayed only when applicable: “BACK UP POWER” when power from the tow boat is interrupted and base has switched over to the back up enclosed battery / “LOW MEMORY” when the memory card used to record the video gets close to full / “COMPUTER OVERRIDE” when computer takes over joy stick control to prevent impact with the bottom.

Any number of blue tooth VR goggles can be synced with base allowing passengers in the tow boat to feel like passengers on the drone.  Independent signals allow everyone to look different directions at the same time and help ensure the pilot dosen’t miss anything interesting.  A button on top of the joy stick enables the pilot to take a still photo of anything he sees thats interesting.  All the information including longitude, latitude, date, and time is captured on the photo making it easy to go back through the video and play back the same location later.

When ready to return, the pilot squeezes the cable in button with index finger on the joy stick and the electric motor in the base winds in the tow cable. When the drone makes contact to the docking conection at the end of the boom, power to the drone is shut down, lights and camera turn off, and a data folder is written to the memory card.  The folder is named “the date and time the drone left the docking connection” and contains a video file of the whole trip and a seperate file with any still photos the pilot took.  The video can be played back later with any VR goggles making it possible to relive the experience over and over.

An App. for a tablet could also be created to work with the base’s GPS to do a grid search.  Enter 3 or more GPS points to form a search area along with the bottom water visabiliy on the tablet App.  The GPS on the base unit sends information by blue tooth to the tablet enabling the App. to provide a line for the power boat driver to stay on so the entire search area is visually covered by the drone.

Towable underwater drones would combine the thrill of being an explorer with the fun of a video game.

Dave Lister

listerlogic.com

Note: This is an original idea by me but there may be similar products or patents already.  I am not an expert, if you attempt to build always consult with an expert and check with all local code and laws.  Build at own risk.