To protect your robot from noises and interferences, there are many way to do
1) You can cover your robot with clothes or black papers.
2) You can use rheostat at receiver LED
3) You can cut a black sheet and a white sheet, then detect it
as reference with a visible light transceiver.
Hide it inside your robot, and use this receiver reading
as reference for other ones.
From our last year's experience, the noise is the strong light reflection of the ground as it is broadcasted by TV. The sensor is unable to detect white line and green ground in some places. Also, the ground is not clean enough. Some black noise(foot print) may lead to unfavorate behavor of the robots. So the utmost important work for me is to shift the stability of our robot.
Another problem for me is that due to mechanic design and the sensor we choose( Banner D11 photoelectroic sensor) , it is hard for me to put the sensor in the front and back of the robots. I can only put the sensor in the sides of the robot.
(1), to count whitelines corrected. Currently I use two sensors as one, that is when the two sensor both detect a white, I think it is a white . both detect black I think it is a black. Else(one black one white) then it is determined by previous condition. However it detects wrong number of lines from time to time. As for my adjust algrothim, it is very important to detect the right number of whitelines.
(2) How can I find my position if in case the robot lost because of a bang of some other accedents. How can I re-position myself?
3)To use a compass. As in this year's competition, there is no lines in a part of the ground. We have tried several methods to position in this area. We have try some expensive gyros, however it doesnot work good enough after one or two minutes. As for compass, we are afraid that it may be affected by the cameras and other electrical equippments in the TV station where we will compete. Have you got any good idea about this?