First successful run of racetrack

Today we started working on the program of the borg. The Lego design of the borg was finished. The only thing we adjusted was the distance between the two RCX light sensors. We are not using the new NXT light sensor anymore since we only have one of them. Also the light values between the RCX sensor and the NXT are not the same and we thought that the RCX sensor gave better distinction between green and black then the NXT sensor. Therefore we decided to stick with two RCX sensors.

Our main idea is that the sensors should be placed in such a way that the black line is between the two sensors. So if both sensors read white values then it should drive straight ahead. If either sensor reads black values then the borg turns into that direction until it reads a white value. This is not a very complex design but it should work well in practice.

To begin with we just used the standard move methods from the Locomotion class. The borg finished the track in around 1.30 minutes. Then we tried our own version of the move methods. There we tweaked the values and we ended up with completing the track in just over 42 seconds. So that was a vast improvement compared to the original locomotion class. Our biggest problem was that the borg could overshoot the turns if it ran too fast. That is why we had to tweak the values for the move methods. We have also noticed a little peculiarity in the behavior of the borg. It does these sudden speed increases for no apparent reason and they only last for a very short time. This is not something we have included in our program so we cannot explain why this is happening. This can have a drastic effect on our borg, especially if it happens in turns. That means the borg will overshoot the turn and miss the black line.

Tomorrow is the final day to prepare the borg for the race. We can probably tweak the values a bit more to get a better time. But only time will tell :)