So last week I sailed the boat a couple of times. The boat is controlled via my a mobile phone. I generally sail the boat at Onepoto Domain, it has a pond with buoys to sail around. It's a popular place for RC sailboat racing, every Sunday morning at 10am RC sail enthusiasts bring their Electron sailboats and race each other. Yesterday we counted 16 boats on the water.
The purpose of sailing the boat is to collect data on how it behaves. The data from the sensors (accelerometer, gyroscope, compass and GPS) is logged and stored for later analysis. I then use that saved data to create a dynamic model of the boat's interaction with it's environment. Such that for a given wind and given direction, the boat will behave in a given way.
Sailing a prototype boat on the water can be risky business. I have had a few times when I have lost control of the boat, mainly due to a weak radio signal. My first prototype used the cellular network for communication, but I found that very unreliable. One time the boat just stopped responding to commands, I believe this was due to losing the cellular signal, or it could have been due to power issues. So I used a better antenna with extension cable that I could put it at the top of the mast. My first test was not successful because during the test the antenna fell into the water and lost all communication ability. After loosing control a few times, I went back to the drawing board and chose to use a long range Wifi antenna. Also, collecting the boat from the pond is hazardous to your health, having had to wade into the pond knee deep once, I vowed not to do that again, since my jeans smelt of pond water for a couple of weeks afterwards.
The solution to was to buy waders in case of having to rescue the boat, so that's what I did before sailing it last Tuesday. But last Tuesday's sailing had another problem. It was windy, too windy. The boat was blown around a lot, and it was difficult to control. Then on Sunday morning I took the boat out for another sail. Since the last sailing I had improved the sensor data collection. However, the Sunday morning sailing had almost no wind. But we got to test out the range of the Wifi, using only my phone and a long range Wifi antenna at the top of the mast I was able to get 240m line-of-sight from the boat. I believe it would go much further, but we ran out of an open area space to test it in.
This week I will focus on analysing and visualising the data collected from the boat sensors. The tool I use to analyse the data is CesiumJS, CesiumJS provide a Google Earth-like interface in your browser. It allows the developer to easily and visually describe a story. In my case I will use it to display the path and orientation of the sailboat.