A line follower robot, or a LFR in short, is a simple autonomous robot that optically tracks a line made on the surface of the floor. That means you have an arbitrary line drawn on the floor and the robot tracks it by moving right along it! The line is sensed using a piece of hardware called a line sensor.
A line sensor can be easily made using a low cost IR Rx/Tx pair. The IR Rx emmits IR radiation and the Rx helps in receiving the waves. See the figure below for working of line sensor.
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Working of Line Sensor |
Schematic for Line Sensor.
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Line Sensor Schematic |
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Actual IR Rx Tx Pair. |
Line Sensor Array.
Actually a group of such sensor units as described above is required to make a line follower robot. We generally use 3 or 5 such sensor unit to make a line sensor array. The complete steps are described below. You need small piece of veroboard (general purpose PCB).
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Actual IR Rx Tx Pair. |
We will fit the sensor at the castor mount of the metal chassis. So we carefully mark the location we need drilling.
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Mark drilling location. |
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Mark the drilling location. |
You can make the hole easily by using a pair of scissor. Just press and rotate.
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Make hole using scissor. |
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Done! |
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Check if it fits. |
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Line Sensor Array Complete. |
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Mounted on Chassis. |
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Mounted on Chassis. |
Professional Line Sensor Array
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Line Sensor Array. |
By Avinash Gupta
good work
nice.we were also done this but here i expected the real time implementation.please post that sir.
Great Work sir!!!
good work sir!
but can u please tell,how do we select the resistor values or are they fixed?
Gee thanks,i recentry joined your website and i`m enjoying every moment of it.I`m interested in control system which could encompass a radius of about a kilometer in robotics,how can we build such a sateritte and a receiver
Sir if we use more than 3 sensors then what will be overall effect of line follower robot and also please tell that can we make the sensor array for more than 3 sensors the same way as you have described above.
I want to connect 5sensor s to my robot how can i connect .please help me
hello sir, I want to know that here you use phototransistor, why you are not using photodiode?? and I didn’t understood the correct operation of phototransistor here?? Please Explain…
Hello Divyansh, do you know the working of photodiode ? If yes ,then tell me.
Dear Sir, I have bought a line sensor(consisting of 5 Tx-Rx) array from your firm that has been provided with 10 wires for connection using a FRC cable. I just wants to the mechanism that if two pins are there for the supply then how does the rest five pairs feed back their output to the MCU back or they use a common ground.
Hello,
I’m interested in making a simple IR Tx/Rx circuit to detect barriers/blockages/intercepts to the IR ray. Can you help or point me in the right direction.
Thanks
@Subra,
Please see this
http://extremeelectronics.co.in/avr-tutorials/door-entry-detection-for-mcu-based-designs/
Avinash,
Thanks for the reply. Can you suggest how this will be used when Rx cannot be installed on the other side. ie. Tx and Rx must be same side. For example: collision detection. Also do you know if this circuit is sold as a unit, so I can just install. Also, I am looking for a way to program the Rx, so when object is detected, additional action can be taken like sounding an alarm. Thanks in advance