How to express your ideas with a program language. Your instructions to the robot. Humans are also have programs - it is our DNA. The DNA of the robots are the programming instructions that we give.
The LEGO Mindstorms EV3 set comes with two LARGE motors. But even though these motors look almost the same they are not quite the same. There are always some differences in their behaviour. If you have more than two motors, because you bought them or you won them somewhere at a competition, it is worth doing an experiment to find which pair of motors works best.
The robot can move with different speed by applying different power to the motors. It will most of the time make smaller deviations when it moves slower. But you can't just move with a power of 10 all the time. This is a way too slow especially for competitions like FIRST LEGO League or World Robot Olympiad. In this video tutorial I would like to discuss the balance between motor power and robot movement error, how does the battery influence the power of the robot and to conduct an EV3-G experiment that will record the values of the Gyro Sensor along with the current power.
Tasks for the Gyro sensor that you can use in STEM classes, while preparing for a competition or just to explore how the sensor works.
Continuing with the Proportional algorithm for following lines. Smooth and stable this is the first part of the PID.
Let's explain the problem of just waiting for the Gyro sensor to detect an angle and think of why the robotics systems work like that.
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.
The Gyro sensor can be positioned horizontally, vertically or at a random angle. Have you ever wonder what does the gyro detect when it is positioned vertically. This is the subject of this video tutorial for the LEGO Mindstorms EV3 Gyro Sensor.
This video tutorial contains the final 2 programs for moving straight with a LEGO Mindstorms EV3 robot. The first program is for proportional compensation that just keeps the robot orientation straight, while the second program is for Integral compensation that returns the robot to the straight line when the robot makes a mistake.
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.
The first part of making the robot move straight is to keep it oriented straight. While it moves it could make an error and turn slightly to the right and then the program should turn in back to the left to make its orientation straight. In this video tutorial, we would discuss how to implement a program to keep the robot orientation straight even when we are pushing or pulling it to either side and in the same time it has different wheels.
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.
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.
The integral part "remembers" the errors that the robot has made in the past and we can compensate for those errors. This will make the robot return back to the line that we would like to keep it aligned.
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 should multiply the error by a certain number and then add it to the steering of the LEGO Mindstorms Steering block. In this way, by changing the coefficient we change how much/fast should the proportional part influence the steering of the robot.
In this video tutorial, we would do a few experiments with the coefficients for the Integral compensation. There are actually two coefficients - "c" and "b"
Follow an object using the LEGO Mindstorms Ultrasonic Sensor. Object moves away, the robot moves with the object. The program is very useful if you are doing STEM classes and you want to demonstrate results. People react very well to a robot following you like a dog for example.
Have you even tried to move the robot not in rotations or degrees or seconds, but in metres. In this episode I am building a new block that could be used to move the robot a specific number of millimetres (mm). You could directly download and use it in your programs.
Stop on detecting an object with the Ultrasonic sensor and move after detecting there is no object. Join of the previous two video tutorials in one
We keep the robot orientation straight while moving, but when we stop the robot could be in a different orientation. This applies for both using the Mindstorms Gyro Sensor when moving straight or the Mindstorms Color sensor when following a line. In this video tutorial, we will do a few examples of when an how this could happen.