fischertechnik ROBOTICS TXT Discovery Set Manual page 25

TXT
Discovery Set
Programming Tips:
You can create a subroutine for "turning a corner." This keeps the main
program clearer.
You probably already have the solution to the task in your head.
But here is another recommendation, just in case:
Always the same, but not exactly?
You have probably noticed that the repetition accuracy of the robot
could be improved. Even when it performs precisely the same task
several times, the result is not always the same. This is due to various
reasons. One of these is that both motors do not rotate at exactly the
same speed. For example, the gearbox for one motor can run with more
friction than the other motor. And because both motors are operated at
the same voltage (nine volts), this makes one motor rotate slower than
the other. Since, in the past, we have controlled our robot using waiting
times, perhaps one wheel has rotated farther during this time than the
other one.
Thus, the solution would be to have both motors rotate at exactly the
same speed. And this is precisely what encoder motors do.
Task 4: Using Encoder Motors
Repeat the last task using the encoder motor elements instead of
the normal motor output and waiting time elements. How to
use these is described in the ROBO Pro help in Chap. 12.6.
Programming Tip:
With the encoder motor element you can control both motors
simultaneously with one program element. With the distance entry field
you can set each motor to turn exactly the distance it is supposed to.
ROBOTICS
25
Mobile_robot_3.rpp