Line Follower Robot.pptx

LINE FOLLOWER ROBOT

What is a line follower robot? • Line follower is an autonomous robot which follows either black line on white surface or white line on black surface. Robot must be able to detect particular line and keep following it.

Components used…. • 1.AVR Development board

• 2.AtMega 16 IC

• 3.L293d IC

• 4.Chassis

• 5.Wheels

• 6.DC Motor

• 7.IR Sensor

• 8.Connecting wires

• 9.AVR Programmer

• 10.A to B cable

• 11. 12 V Adaptor

Block Diagram of the Project • The line follower robot built in this project is divided into 4 blocks. The following image shows the block diagram for line follower robot.

Block Diagram Description • Sensors (IR Sensor): We have used IR Sensor Module as the line detecting sensor for the project. It consists of an IR LED and a Photo diode and some other components like comparator, LED etc. • Controller (AVR): AVR is the main controller in the project. The data from the sensors (IR Sensors) will be given to AVR and it gives corresponding signals to the Motor Driver IC.

• Motor Driver (L293D): L293D Motor Driver IC is used in this project to drive the motors of the robot. It receives signals from AVR based on the information from the IR Sensors. • Motors : Motors are the devices which make the robot movable. Motors convert electrical energy into physical motion.

Working of IR Sensor • IR reflective sensors have one emitter (IR LED) and one receiver (Phototransistor or photo diode. If we have white surface it reflects the light and it will sensed by the receiver, similarly if we have black surface it absorbs the light and receiver can not sense light.

L293d IC • L293D is a dual H-bridge motor driver integrated circuit (IC). Motor drivers act as current amplifiers since they take a low-current control signal and provide a higher-current signal. This higher current signal is used to drive the motors. L293D contains two inbuilt H-bridge driver circuits. In its common mode of operation, two DC motors can be driven simultaneously, both in forward and reverse direction.

Dual H Bridge An H bridge is an electronic circuit that enables a voltage to be applied across a load in opposite direction. These circuits are often used in robotics and other applications to allow DC motors to run forwards or backwards.[1] Most DC-to-AC converters (power inverters), most AC/AC converters, the DC-to-DC push–pull converter, most motor controllers, and many other kinds of power electronics use H bridges. In particular, a bipolar stepper motor is almost invariably driven by a motor controller containing two H bridges.

• H bridges are available as integrated circuits, or can be built from discrete components.[1] • The term H bridge is derived from the typical graphical representation of such a circuit. An H bridge is built with four switches (solid-state or mechanical). When the switches S1 and S4 (according to the first figure) are closed (and S2 and S3 are open) a positive voltage will be applied across the motor. By opening S1 and S4 switches and closing S2 and S3 switches, this voltage is reversed, allowing reverse operation of the motor. • Using the nomenclature above, the switches S1 and S2 should never be closed at the same time, as this would cause a short circuit on the input voltage source. The same applies to the switches S3 and S4. This condition is known as shoot-through.

Working of LFR • Line follower robot senses black line by using sensor and then sends the signal to AVR. Then microcontroller drives the motor according to sensors' output. • 1. When both left and right sensor senses white then robot move forward.

2.If left sensor comes on black line then robot turn left side.

3. If right sensor sense black line then robot turn right side until both sensor comes at white surface. When white surface comes robot starts moving on forward again.

4. If both sensors comes on black line, robot stops.

Program Explanation If a sensor comes on black surface then it gives output 0 and if it comes on white surface then it gives output 1.There are 4 cases: Input

Output

Left Right Left Motor Sensor Sensor

Movem ent Right Motor Of Robot

LS

RS

LM1

LM2

RM1

RM2

0

0

0

0

0

0

Stop

0

1

1

0

0

0

Turn Right

1

0

0

0

1

0

Turn Left

1

1

1

0

1

0

Forwar d

CODE #include #define F_CPU 16000000UL #include void main() { DDRB=0xFF; DDRA=0x00; while(1) { if(PINA=0x02) { PORTB=0x01; _delay_ms(1000); } else if(PINA=0x04) { PORTB=0x04; } else if(PINA=0x06) { PORTB=0x05; } else { PORTB=0x00; _delay_ms(1000); } } }

Applications of line follower robot • Industrial Applications: These robots can be used as automated equipment carriers in industries replacing traditional conveyer belts. • Automobile applications: These robots can also be used as automatic cars running on roads with embedded magnets. • Domestic applications: These can also be used at homes for domestic purposes like floor cleaning etc. • Guidance applications: These can be used in public places like shopping malls, museums etc. to provide path guidance.