Virtual Line Follower

This post is about the Virtual line follower android app. This app lets you learn about line follower without any complex circuit. In this app, you can adjust parameters like the number of sensors, the distance between sensors which is a very time consuming and costly task to do with a practical line follower. You can write your own logic and run the robot.
If you don't have an android device then you can download any Android emulator available and run this app.

Let us look at the geometry of the robot.
Following parameters of line follower bot are adjustable
1. The number of sensors. You can use as many sensors you want in a straight array fashion.
2. Distance between sensors (x): Distance between sensors can be chosen in terms of pixel length. The distance between consecutive sensors is the same for all sensors.
3. Distance between motors (L) can also be changed.
4. The distance of the sensor array from the motor axis can be changed.
5. Sensors are arranged from left to right as shown in the figure below.

Line Follower Geometry

The sensor state is written from the leftmost sensor to the rightmost sensor. For example for two sensors S0, S1 possible states are 00, 01, 10, 11.

Motor output can be from -1 to +1. Where -1 is for maximum reverse speed and +1 for maximum forward speed.

Examples to try inside the app:

1) Two sensors:

for "00" state go forward by left motor=1 and right motor=1 

for "01" state go right by left motor=1 and right motor=0 

for "10" state go left by left motor=0 and right motor=1  

for "11" state go forward by left motor=1 and right motor=1 

Inside App, the following should be input

Sensor state:

00

01

10

11

Left Motor:

1

1

0

1

Right Motor:

1

0

1

1

2) Three sensors:

for "001" and "011" states go right by left motor=1 and right motor=0 

for "110" and "100" state go left by left motor=0 and right motor=1  

for "010" state go forward by left motor=1 and right motor=1 

Otherwise, go forward in simple robot. 

Inside App, the following should be input

Sensor state:

001

011

100

110

010

Left Motor:

1

1

0

0

1

Right Motor:

0

0

1

1
1

For PID go here https://crackeconcept.blogspot.com/2020/03/virtual-pid-line-follower.html

the app is out! Try now.

https://play.google.com/store/apps/details?id=com.gaurtavm.virtuallinefollower