For the final competition we decided to compare different algorithms by testing them repeatedly. Then whichever has the smallest error (after tuning) and is most stable is the one used for the test. Remy’s two-brick design came out on top with a average error of less than a millimeter. A small demonstration is shown in the video.
A small hardware modification was done to the sensors to increase the sensors’ sensitivity. We came across information that, when on active mode, the LED shines directly into the receiver part of the light sensor. This can be solved by blocking light from reaching the receiver directly. (Note the piece of paper in the middle.)
This made the difference between the readings of black and white twice as big, from 15 percent to 30 percent. After that we looked into the dsensors.h file to see how the scaled value LIGHT was defined. We found this
#define LIGHT(a) (147 - ds_scale(a)/7)
This basically states that the scaled value is then divided by 7, effectively decreasing the resolution by a factor 7! We defined a new scaled value in our own programs by basically multiplying the entire rule by 7:
#define LGHT(a) (1029- ds_scale(a))
Now we have an improved sensitivity and resolution. With this we are less sensitive to disturbances.
We ended up finishing third in the race!
Tags: Final, Line Tracking, Results, Video
