Here is the little boat pulling the very large pontoon boat into the wind and the waves. Speed read from GPS receiver.

The boat was put into the water on Lake Lanier to see if it would even float and remain upright. Amazingly, the boat did remain upright, watertight and extremely stable. The small trolling motor was run at 12 volts and 24 volts. At either voltage, there was plenty of thrust to drive the boat through the water.

The boat at one point was pulling the 6,000 pound houseboat at 0.7 mph into the wind and waves.

Now that we have proven the boat is stable, and it did not sink, we will add the solar cells and the autonomous navigation system.

Controller Tray

The control computer, cpu battery backup, Iridium modem, current sensor, and power switches are mounted on a tray that fits into the rear of the upper middle tube.

Steering Controller Motor

The motor that rotates the shaft of the trolling motor is mounted in the same tube as the controller tray. The motor has an incremental shaft encoder rear mounted that translates the motor shaft rotation into quadrature pulses.

Trolling Motor

This is the main proplusion motor. The motor is a Minn-Kota saltwater trolling motor that has the capability of 55 pounds of thurst at full speed - 24 Volts dc and 6 Amps. For longer endurance of the motor, it will never go above 50% of rated thrust.

Vessel in Dry Dock

Structural Concept

The vessel will have four ten feet long tubes held together by an aluminum structure. Each of the three aluminum surfaces shown in the picture on the left will be covered with 159 mm square solar cells, as represented by the black square. An aluminum wedge structure will be on the front to cut through the water, and the Minn-Kota trolling motor will be on the rear end of the vessel. The motor will be on a shaft that will rotate for steering 120 degrees.

Vessel in Dry Dock


Here is the aluminum structure on its back ready for the insertion of the 6 inch diameter schedule 80 pvc tubing.

Trip

The trip via each waypoint is 6217 mile long. The path was chosen to pick up the ocean current to the United States used by the early traders to this country. Currents for the trip during the summer months are favorable South from Spain/Portugal to the Western Coast of Africa, turning Northwest to near Puerto Rico and on to Tybee Island, Georgia.

Currents will be monitored in near real time from the NOAA satellites at http://www.oscar.noaa.gov/ . If an early summer hurricane or storm should be encounterd, a new set of trip waypoints will be downloaded over the Iridium link. Worse comes to worse, the boat will be stopped until conditions improve.

Simulated Trip

Before the actual trip is undertaken, a simulated trip with actual route coordinates will be done.

The distance between each waypoint was divided into 100,000 points and the latitude and longitude were calculated. These points were then inserted into NEMA 0183 GPRMC sentences that would normally be received from the GPS system. The simulated sentences will be fed to the vessel's control computer over a serial port that normally receives the output of the GPS receiver.

Several type of problems will be introduced at various points to simulate anticipated problems such as the control computer losing control, unexpected shutdown, or loss of total power.

The objective of this madness is to have a small solar powered, autonomous vessel, named the Spring AUV, traverse from the northern Spain/Portugal border to Tybee Island, Georgia without any intervention. A Google Earth map with the intermediate waypoints is presented in the picture to the left.

The vessel's Parallax Basic Stamp(s) (BS2P) will use gps data to navigate and software I have written to control all the systems.

An Iridium short burst data link will be used to relay positional information and key system parameters back to Savannah. The Iridium satellite network will link location information four times a day to Savannah, and the vessel's position will be posted to a map on this blog.

The boat is ten feet long and very narrow to insure it can only be stable upright. The boat consists of four six inch pvc tubes. It will be electrically powered by 54 solar cells provided by Suniva Corporation in Atlanta, GA, and it will be propelled across the Atlantic by a Minn-Kota saltwater trolling motors.

Portugal to Savannah, GA AUV