Overview
In this latest edition of robotics related articles, let us look at some basics of line tracking/following as we build up towards Level-3 autonomous robot construction.
Line tracking is a very important notion in the world of robotics as it give to the robot a precise, error-less and easy to implement navigation scheme.
As you may have seen, many robotics competitions promote this concept, by adding lines on the playground for the robot to follow, or sometimes, the sole purpose of the competition is to race with other robots following a line along a track.
1] Number of cells in a sensor
A line sensor is one that will gather information about the position of a line traced on the ground underneath the robot, to help it to navigate through an eventual grid of lines and intersections.
For the software to function correctly, the sensor's electronic circuits have to provide a maximum number of information about that line.
As you can see in below figure 1, a line sensor is composed of a number cells and each cell is composed of a sender and a receiver.
The particularity of this sender/receiver pair, is that it sends light that shall be reflected by the line to be detected but not by the eventually opaque background surrounding this line. Any sender/receiver pair that is able to make a difference between a line and the rest of ground (of a different color) can be used in a line sensor.
Usually, to make it easier on the designer of the sensor, there is an important contrast between the line and the ground (for example: white line on a dark blue ground), But in case there isn't enough contrast, there is a method to easily build a line sensor adapted to that specific situation, relying on old physics rules that states that a colored surface will absorb the light of different colors, and reflect the light of the same color.
For example, If you want to build a line sensor to detect white lines drawn on a light blue floor, you can send red light, as the blue will absorb all of it, and the white line will reflect all of it.
In this latest edition of robotics related articles, let us look at some basics of line tracking/following as we build up towards Level-3 autonomous robot construction.
Line tracking is a very important notion in the world of robotics as it give to the robot a precise, error-less and easy to implement navigation scheme.
As you may have seen, many robotics competitions promote this concept, by adding lines on the playground for the robot to follow, or sometimes, the sole purpose of the competition is to race with other robots following a line along a track.
1] Number of cells in a sensor
A line sensor is one that will gather information about the position of a line traced on the ground underneath the robot, to help it to navigate through an eventual grid of lines and intersections.
For the software to function correctly, the sensor's electronic circuits have to provide a maximum number of information about that line.
As you can see in below figure 1, a line sensor is composed of a number cells and each cell is composed of a sender and a receiver.
The particularity of this sender/receiver pair, is that it sends light that shall be reflected by the line to be detected but not by the eventually opaque background surrounding this line. Any sender/receiver pair that is able to make a difference between a line and the rest of ground (of a different color) can be used in a line sensor.
Usually, to make it easier on the designer of the sensor, there is an important contrast between the line and the ground (for example: white line on a dark blue ground), But in case there isn't enough contrast, there is a method to easily build a line sensor adapted to that specific situation, relying on old physics rules that states that a colored surface will absorb the light of different colors, and reflect the light of the same color.
For example, If you want to build a line sensor to detect white lines drawn on a light blue floor, you can send red light, as the blue will absorb all of it, and the white line will reflect all of it.
![Picture](/uploads/2/8/3/9/28397929/6319813.png?250)