It went very well, so I decided to build an improved version of the sonar boat which you can see in the picture above.
In the video below you can see the performance of the boat.
The ArduPilot worked very well and the speed, size and the operation range were satisfying. But the propulsion nozzle turned out to be very sensitive to sea plants. And in windy conditions with waves and in curves, it was rolling quite a lot. I measured a big lake with it as you can see in the Google Earth picture on the bottom of this page, but I decided to build a more stable boat.
So now I tell you about the Making of the improved boat:
The new boat should be able to carry more batteries, be more stable in the water, be faster and not be too much bigger. So I decided to build a small trimaran. I started to plan it with DELFTship which is for free and easy to use.
I also used NX to plan the space I needed in the hull as you can see in the pictures below:
The next step was the making of the positive mold. I could use the laser cutter of the Fablab in Aachen (https://hci.rwth-aachen.de/fablab) to cut the sections that were exported from DELFTship out of 3mm MDF.
The resin has a curing time of 40 min which makes it very easy to use. The result looked like this:
Before letting the boat into the lakes I wanted to be able to find it after its work under any circumstance so I included an XBee 900 pro for a GPS-data link. Also I wanted to be able to manipulate the track of the boat by a joystick with the XBee, so I printed a case for a small remote control to include the XBee, a thumbstick, a small Arduino and other switches.
After that final step, I was ready for the next lakes.
After improving the ArduPilot parameters the trimaran performed very well. I could switch the boat on, put it into the water and have breakfast at home, before picking it up after several hours and it was always there. If the wind had blown it away, I could track it via the XBee and with the Earth Bridge, I could watch its position live on Google Earth.
In this Video you can see the performance of the boat in different conditions:
The following pictures will give you some impressions of the measuring:
In this last picture, you can see the work i have done so far with the boats and in the area, there will be many more lakes for measuring.