PmWiki | Student / Lab 3: Line Following

Daniela Garcia (Red Cohort)

Summary:

The purpose of this lab was to program the create to follow a line through the use of the create's cliff sensors. The create senses white at a value above 600 and black at a value below 600. The program is set up so that if the front left cliff sensor reads black, the right wheel will drive faster and vice versa. If both the left and right cliff sensors sense black, then the create wil move slightly back and forth in place to relocate the black line. If both of the sensors sense white then the create will keep driving foward until a black line is sensed.

Lessons Learned:

When using WINAVR, the USB ports must always be checked because they change frequently.
Codes must be typed with no errors (semi-colons and parenthesis must be added).
Each create senses different values for black and white.
The create will do what you tell it to do!
It is necessary to have a larger difference in the speeds of the wheels because it makes the robot turn more aggressively.
Not only can a code have an infinite number of "else if" statements but also "if" statements.
The speed that the robot is turning affects it, it is more accurate for the create to turn at a larger difference in velocity than a smaller difference. For example, it is better for the create to drive (200,20) than (30,20).
There are a lot of different ways to go about programming the robot to do the same task.

Problems on the course:

My robot, ox02 was having trouble making sharp turns (90 degrees) and passing the difficult corner with many different shapes. The robot would deviate from the course and pick up line following once it hit the path. This is due to the fact that the robot has trouble when there are tight spaces where a lot of turning is necessary. If I could add something to the create, I would add on more sensors or more sensitive sensors to the robot so that it would be easier to navigate. I could use light sensors so that there are more readings for the create to go by. The additional light sensor would be most helpful if placed directly in the front center of the robot.

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