30-07-2011, 02:41 PM
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ABSTRACT
Line following robot is a robo car that can follow a path. The path can be visible like a white line on the black surface (or vice-verse). As a result of this line following property it has many applications in future and now itself.
Line following robot with pick and placement capabilities are commonly used in manufacturing plants. These move on a specified path to pick the component from specified location and place them on desired locations.
Basically,a line-following robot is self operating robot that detects and follows a line drawn on the floor. The path to be taken is indicated by a white line on a black surface. The control system used must sense the line and manoeuvre the robot to stay on course while constantly correcting the wrong moves using feedback mechanism,thus forming a simple yet effective closed-loop system. As a programmer you get an opportunity to ‘teach’ the robot how to follow the line thus giving it a human-like property of responding to stimuli.
The robot has two sensors installed underneath the front part of the body, and two DC motors drive wheels moving forward. A circuit inside takes an input signal from two sensors and controls the speed of wheels’ rotation. The control is done in such a way that when a sensor senses a white line, the motor slows down or even stops. Then the difference of rotation speed makes it possible to make turns
1.INTRODUCTION
The line following robot, operates as the name specifies. It is programmed to follow a white line on a dark background and detect turns or deviations and modify the motors appropriately.
It consist of sensors,comparators,microcontroller and motor drivers.We uses darlington phototransistor as the sensor. The core of the robot is the AT89C51 microcontroller.Here it act as a decision making device.
It consist of two dc motors and driver ic to steer it. The differential steering system is used to turn the robot. In this system, each back wheel has a dedicated motor while the front wheels are free to rotate. To move in a straight line, both the motors are to be rotate at same speed.To manage a turn a motor is to stop at correct circumstances according to sensor output.
2.BLOCK DIAGRAM
3.BLOCK DIAGRAM EXPLANATION
Fig.1 show the block diagram of automated line following robot. It consist of mainly four parts: two sensors,two comparators,one decision making device and two motor drivers. The robot is built using micro controller AT89C51,motor driver L293D,operational amplifier LM324,phototransistor and a few discrete components.In the circuit, the sensor are used to detect the white strip on a black background. The sensor output is fed to the microcontroller, which takes the decision and gives appropriate command to motor driver L293D so as to move the motor accordingly
3.1 sensor: The sensor senses the light reflected from the surface and feeds the output to the comparator. When the sensor is above the white background the light falling on it from the source reflects to the sensor, and when the sensor is above the black background the light from the source doesn’t reflect to it. The sensor senses the reflected light to give an output, which is fed to the comparator.
3.2 comparator: The comparator compares the analogue inputs from sensors with a fixed reference voltage. If this voltage is greater than thereference voltage the comparator outputs a low voltage, and if it smaller the comparator generates a high voltage that acts as input for decision-making device(microcontroller).
3.3 microcontroller: The micro controller is programmed to make the robot move forward,turn right or left based on the input coming from the comparator. The outputs of the microcontroller are fed to the motor driver.
3.4 motor driver: The current supplied by the microcontroller to drive the motor is small. Therefore a motor driver ic is used. It provides sufficent current to drive the motor.
ABSTRACT
Line following robot is a robo car that can follow a path. The path can be visible like a white line on the black surface (or vice-verse). As a result of this line following property it has many applications in future and now itself.
Line following robot with pick and placement capabilities are commonly used in manufacturing plants. These move on a specified path to pick the component from specified location and place them on desired locations.
Basically,a line-following robot is self operating robot that detects and follows a line drawn on the floor. The path to be taken is indicated by a white line on a black surface. The control system used must sense the line and manoeuvre the robot to stay on course while constantly correcting the wrong moves using feedback mechanism,thus forming a simple yet effective closed-loop system. As a programmer you get an opportunity to ‘teach’ the robot how to follow the line thus giving it a human-like property of responding to stimuli.
The robot has two sensors installed underneath the front part of the body, and two DC motors drive wheels moving forward. A circuit inside takes an input signal from two sensors and controls the speed of wheels’ rotation. The control is done in such a way that when a sensor senses a white line, the motor slows down or even stops. Then the difference of rotation speed makes it possible to make turns
1.INTRODUCTION
The line following robot, operates as the name specifies. It is programmed to follow a white line on a dark background and detect turns or deviations and modify the motors appropriately.
It consist of sensors,comparators,microcontroller and motor drivers.We uses darlington phototransistor as the sensor. The core of the robot is the AT89C51 microcontroller.Here it act as a decision making device.
It consist of two dc motors and driver ic to steer it. The differential steering system is used to turn the robot. In this system, each back wheel has a dedicated motor while the front wheels are free to rotate. To move in a straight line, both the motors are to be rotate at same speed.To manage a turn a motor is to stop at correct circumstances according to sensor output.
2.BLOCK DIAGRAM
3.BLOCK DIAGRAM EXPLANATION
Fig.1 show the block diagram of automated line following robot. It consist of mainly four parts: two sensors,two comparators,one decision making device and two motor drivers. The robot is built using micro controller AT89C51,motor driver L293D,operational amplifier LM324,phototransistor and a few discrete components.In the circuit, the sensor are used to detect the white strip on a black background. The sensor output is fed to the microcontroller, which takes the decision and gives appropriate command to motor driver L293D so as to move the motor accordingly
3.1 sensor: The sensor senses the light reflected from the surface and feeds the output to the comparator. When the sensor is above the white background the light falling on it from the source reflects to the sensor, and when the sensor is above the black background the light from the source doesn’t reflect to it. The sensor senses the reflected light to give an output, which is fed to the comparator.
3.2 comparator: The comparator compares the analogue inputs from sensors with a fixed reference voltage. If this voltage is greater than thereference voltage the comparator outputs a low voltage, and if it smaller the comparator generates a high voltage that acts as input for decision-making device(microcontroller).
3.3 microcontroller: The micro controller is programmed to make the robot move forward,turn right or left based on the input coming from the comparator. The outputs of the microcontroller are fed to the motor driver.
3.4 motor driver: The current supplied by the microcontroller to drive the motor is small. Therefore a motor driver ic is used. It provides sufficent current to drive the motor.
