Thursday, September 25, 2008

Lesson 4

Todays lesson
Today have to operate with a regulating system. We have to make a "copy" of the Sejway with the NXT.

The NXT Segway
We started to build the NXT Segway as instructed and downloaded the code for the NXT Segway. It is expected that it will fall into the ground.

As expected it fall. We also noticed that the wheels was spinning in the wrong direction. This was solved by changing the wheel direction in the software.
It was also clear that that the light sensor was vibrating a lot, so it would be impossible for the NXT Segway to balance. So we remounted the sensor so it wasn't vibrating.

Now it was able to balance for a couple of seconds, but it was still falling. We tried to put on some counter weight, see picture below. Now it balanced for about 5 seconds.

We tried to raise the counter weight for better balance, see picture below. We was working out from the principe where you are balancing a stick on the finger, the longer the stick is, the easier it is to balance.

We got it balancing for 8 seconds.

We now spotted another problem, the motor stopped for about every 8 seconds. It could be because of the NXT garbage collecting. For investigation we wrote out the memory in the display of the NXT and it didn't look like it was garbage collecting. We did never find the source of the problem.

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