|
Explore TEAMS!
|
Student /
SonLab3LineFollowingResults Summary: The goal of this lab was to program the Create to follow a path of black electrical tape on a white floor/board. How would it respond to a curved path? T intersection? Sharp angles?My create was able to navigate turns, pick a path when there was a fork or intersection, and was able to turn 90 degree angles.
The Create successfully executed the desired commands --- turning a certain way when encountering certain ranges of values on either cliff sensors, and turning on LEDs to indicate which sensors detected black. At first, these commands would not execute properly and the Create just spun in a circle. The problem to this turns out to be the sensor values to read black. I fixed this by using Realterm to find this robot¡¦s unique readings for black electrical tape (I used the front right and front left sensors) and changed the values in my codes.
Limitations: The Create would get stuck when it reached an L shaped corner coming from the right. Since it was programmed to turn left should it meet some cross-section, it kept turning into the corner instead of turning right and continuing the path. I¡¦m not sure if it¡¦s possible to program the Create to take another course of action after executing the primary command a couple unsuccessful times first.
Adding: I would probably add adjustable, external sensors to replace the Create¡¦s existing cliff sensors. This way, they sensors could be custom adjusted to the line¡¦s width and could turn and follow the path without stalling and sputtering at a cross-section or sharp and small cruves.
Pre-Lab #1-8:
1) Black Electrical Tape: Front R (300-400), Front L(600-700)
White Surface: Front R(1400+), Front L(800+)
Use the average in-between the value readings for Black and White. This is the “safety zone’ (neither black nor white readings)
so that BLACK or WHITE can be differentiated and courses of actions can be determined.
3) LEDs turn on because it senses the black tape (value of less than 800).
4) LEDs WILL change if you push the robot off the tape. The white paper gives different values (greater than 800)
that make the statement untrue (e.g. 1500 is not less than 800) therefore it cannot execute the commands because conditions
haven't been met.
5) LEDs do not turn on for reasons explained above in #4. If you push the robot onto the black tape,
the statement will be true and the LEDs will turn on.
6) You can use "on, off, 1," or "0" in the "while" loop blank. Using "off" or "0" is better so that you won't have
to hold down the play button for the program to run. "Off" may be better because it's easier to understand (it's in English!).
7) The sensors are pretty sensitive to the change of color since even dark shadows on the white surface threw the Create off
the line path. But this varies with the sensor values for black for each Create and each Create's 4 sensors, and also the
difference between the average and the black and white values (large safety range is less sensitive with more room for error).
8) (See Lab 3 Codes!)
|