EV3 Phi. Move tank block - finish the whole 180 degrees turn Pro Preview

Once you start turning how to do you a whole 180 degrees turn. The robot almost does it, but not completely

  • #384
  • 17 Mar 2017
  • 2:41

180 degrees turn with Mindstorms robots

The duration of the turn configured by the previous episode is not enough. We must increase the number of seconds/rotations that the motor moves in order to complete a full 180 degrees turn. The experiments with our robot give us a value of 2.7 rotations.

Experiment with another ratio for left and right turn

The ratio is currently 10% power for the left and 90% power for the right motor and for this we have 2.7 rotations. But how many rotations should we make if the ratio is 20% left and 90% right. It would be more, but how much more.


The robot almost turns around the pole and in this video we'll finish the turn.

In the program we have the block for moving forward and then we have the block for turning left. And the duration of the turn is not enough. We must increase the number of rotations that the motors should do. And after a few experiments we've reached a value of 2.7. This will make the whole robot move forward and turn 180 degrees. So, the robot will turn. The next experiment and you can do it for your robot and for your battery it should be basically the same. We turn with the left motor with a power of 20 and with the right motor with a power of 80. At the end we add one more steering block. At the end of the program. And this steering block is just moving forward with a power of 50. What you'll have: move forward, turn, move forward. And for this block again we've just experimented with the values and we've seen that 20 is good for the left motor and 80 is good for the right motor and the whole duration of the turn should be 2.7. Download and run.

It is not 2.7. You see that 2.7 is still not enough as a number of rotations for turning. Probably it was 3.7 let's try with 3.7.

And I'll download and run the program again.

Yes, for this robot we have the value 3.7 and the robot will make a full U turn to 180 degrees. And in this way the robot will move forward, turn and return back to base.

Lessons with this tutorial

This tutorial is used in the following lessons

  1. EV3 Phi. Introduction to robotics with LEGO Mindstorms / Programming Arc turns. Adjusting robot speed

    1. ***Tutorial****

    2. ***Task****

    3. ***Tutorial****

    4. ***Tutorial****

    5. ***Task****

    6. Move tank block - finish the whole 180 turn
    7. ***Tutorial****

    8. ***Task****

    9. ***Task****

    10. ***Task****