Programs

The block has the following parameters from left to right:

• Maximum angle – the maximum steering angle of the front wheels. It is measured from position of straight wheels, to maximum left or right position.
• Relaxation coefficient – the relaxation coefficient regulates how smoothly the robot follows the line. The default value is 1. In general the range for the coefficient is between 0.5 till 2. If the difference between the value measured by the sensor on black and on white is great i.e. on black is 10 and on white is 80, then the coefficient should be smaller. If those values are closer, then the coefficient should be larger.
• Value on black – the value detected by the light sensor in reflected light mode when it is on the line.
• Value on white – the value detected by the light sensor in reflected light mode when it is outside the line.

EV3 PLF-block for LEGO front-wheel steered robots. The block has two relaxation coefficients – one for steering to the left and one for steering to the right. The aim is to make the robot follow a line smoothly when the color sensor is positioned closer to one of the wheels.

The block has the following parameters from left to right:

• Maximum angle – the maximum steering angle of the front wheels.
• Relaxation coefficient left – the relaxation coefficient regulates how sharply the robot responds to error, turning left. The default value is 1.
• Relaxation coefficient right – the relaxation coefficient regulates how sharply the robot responds to error, turning right. The default value is 1.
• Value on black – the value detected by the light sensor when it is on the line.
• Value on white – the value detected by the light sensor when it is outside the line.

- Download the project created in this episode, including the program compating the 3 sensors - the NXT Light Sensor, the NXT Color Sensor and the EV3 Color Sensor and the a program, that displays the raw sensor value.

Program for displaying the value of the sensor on the screen

In this program we demonstrate how to program a SPIKE robot to follow a line with the aid of a color sensor. In this program, we use the sensor value to calculate a number to feed in the "start moving" command. The numbers in this program depend highly on the size of the wheels of the robot, the distance between the wheels, the color sensor reflected light range, the wheels friction, and the speed at which the robot moves. The numbers in the program must be adjusted for every case, and are in no meaning optimal to use as is, in other projects.

This program was intended for and tested on the Gazon robot

In this program we demonstrate how to program a SPIKE robot to follow a line with the aid of a color sensor. Make sure the line is big enough for the sensor to detect it and react to it. For some thinner lines, the speed of the robot can be lowered, but if that does not help, the program can be easily adapted to work with reflected light intensity.

This program was intended for and tested on the Gazon robot

In this program we demonstrate how to program a SPIKE robot to follow a line with the aid of a color sensor. Make sure the line is big enough for the sensor to detect it and react to it. since we are measuring reflected light rather than the color of the line, we can and have implemented multiple states line following.

This program was intended for and tested on the Gazon robot

- Follow black line using two light sensors.

This is the example program using the blocks available at  Blocks Package for Advance Calibration of LEGO Mindstorms EV3 Color/Light sensors. The program makes the robot find the minimum and maximum values and to calibrate the current sensor value depending to the min and max.

 

The program uses the light and color sensor along with the motion sensor to accomplish the mission. It contains a few interesting tricks on detecting lines and configuring the behavior of the robot with specific params.

The program uses the light and color sensor along with the motion sensor to accomplish the mission. It contains a few interesting tricks on detecting lines and configuring the behavior of the robot with specific params.

In this program we demonstrate how to program a SPIKE robot to follow a line with the aid of one color sensor and detect an intersection with another color sensor. Make sure the line is big enough for the sensor to detect it and react to it. For some thinner lines, the speed of the robot can be lowered, but if that does not help, the program can be easily adapted to work with reflected light intensity.

This program was intended for and tested on the Gazon robot

In this program, we demonstrate how to program a SPIKE robot to follow a line with the aid of one color sensor and detect and stop at the second intersection with the aid of another color sensor. Make sure the line is big enough for the sensor to detect it and react to it. For some thinner lines, the speed of the robot can be lowered, but if that does not help, the program can be easily adapted to work with reflected light intensity.

This program was intended for and tested on the Gazon robot

- Allign on black line using two light sensors;

Use this program and you won't have problems in following lines with EV3 Mindstorms Color Sensor: