Following lines, detecting colors, responding to light. It is still far from "seeing", but the LEGO Mindstorms EV3 & NXT sensors could be very useful when used properly.
In this tutorial we present a way to align your robot to a black line. Go through common difficulties, that the teams face, when they need to align their robot, and provide a solution for them.
Continuing with the Proportional algorithm for following lines. Smooth and stable this is the first part of the PID.
Last part of the series. The final touch of the program makes sure that it works and is following the line with the LEGO Mindstorms EV3 Color Sensor in a smooth and fast way.
This video lesson is a revised version of Episode #1. Matt Gipson requested it in a comment. Using the EV3-G software we have developed a very simple program for following a line with two LEGO MINDSTORMS color/light sensors.
In this tutorial we introduce the basic algorithm for following a line with one sensor and review the algorithm for quickly followwing a black line with one sensor, implementing both with the Mindstorms EV3 robotics kit.
We extract the Proportional Line Following algorithm into a new block with parameters. This allows us to experiment with the Threshold, Constant Speed and Relaxation Coefficient. You can now easily use the block in you other programs without having to implement it.
Use the color sensor to count the lines and stop on the third line. We do not use the wait block for this.
The program from part 3 should be refactored and improved to make it easier to understand and support. We extract most of the repeatable behaviours in a loop and this reduces the size of the program three times in terms of the number of blocks used.
The color sensors supports different modes of working. In this video we are working with the Reflected light, which is not actually the detected color. Most robotics sensors actually work with reflected light and you should definitely learn how to use this mode.
We list the number of decisions that the robot is making while following the line. Then, we group them and decide on the number of sensors to be used.
We follow a line. We start from the Smooth Proportional Line Following program and modify it a little for this program. We follow the line with the middle sensor attached on port 2.
This robot has a color sensor and this sensor is used for following lines. Additional Mindstorms EV3 sensors could be place on the robot, like a Gyro sensor or a second Color sensor.
How do you detect a cross-section and move from following the main line to following the crossing line. In this series of video tutorials we are starting with a very simple solution that could work in most of the cases. It is especially useful for the FIRST LEGO League Trash Trek competition where there is such a section.
Tasks on using the LEGO EV3 Mindstorms Color sensor. Quite fun and useful for different STEM classes or just to get to know the sensor.
It's inevitable. While following this gapped line we would reach a gap. The robot must somehow understand that there is a gap and must make a decision on what to do. For detecting the gap we use the Rotation Sensor. Not the most popular, but very convenient in many cases. Check out the video.
We've detected the gap. It's time to move over it. This is difficult because we have to detect where the line is after the 0.1 meters gap on the line following field.
"What is the light in the room?" - should it even matter. You can use one program for all lighting conditions by calibrating the color/light sensor of the LEGO Mindstorms EV3/NXT robots.
Next important state is Turn Right with our robot. This happens when we detect a line on the right.
This second part continues with importing two previously developed in Episode 53 blocks into our program. With them we can for align to lines. We program the robot to align to the cross line and start following it.
Next state in our state machine programming pattern is the "Turn Left" state and the corresponding behaviour.
We can Turn Right. We can Turn Left. How do we decide which way to go if there are lines both to the left and to the right. Check out the video.
All worked as expected, up until know because the robot got lost. This happens when we turn right and the line does not continue to the right. Now the robot must somehow understand that it is "lost" and escape.
After several questions about the use of the LEGO Mindstorms NXT Light Sensor with the EV3 software, we have decided to go through this problem in this video tutorial and pay special attention to the Raw Sensor Value Block.
Играта "Развален телефон" с LEGO роботи разчита на сензора за цвят, но понякога той не работи както трябва. Сензорите за цвят може да бъдат повлияни от много външни фактори като позицията му и светлината в стаята. Този урок демонстрира как да се съобразим с тези фактори и да решим проблемите възникнали от тях.
We discuss the state of "Lost" and the different ways we could escape this state. We also build the next step of our State machine programming pattern where the next state is determined by the previous state.
In this tutorial, we would implement a program that finds the minimum and maximum value detected by the sensor and stores this two values in an array.
