31-03-2014, 03:01 PM
Defense Robot
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INTRODUCTION
A robot is a virtual or mechanical artificial agent. In practice, it is usually an electro mechanical system which, by its appearance or movements, conveys a sense that it has intent or agency of its own.
With the help of this “Wireless Microcontroller Based Intelligent Army Robot” the army people can know the position of battle field and can detect the location of enemy without entering to the battle itself, for this a micro wireless camera is fitted on the robot where the video and voice transmitted to the required place i.e. control room. The trolley type robot is constructed with the help of a two tires which is connected to the two motors, one to move the forward and reverse and other to move towards left and right with gear facility.
Our aim in building this project is to create a wireless controlled robotic vehicle which can be operated through a range of 100 meters using 433 MHz RF transmitter and receiver. This vehicle is equipped with a magnet detector can detect any land mine on its way, and wireless camera which will transmit the live pictures and videos remotely.
This unit is helpful and useful for surveillance of an area in defence grounds for enemy, spying purpose where the human reach is not recommended or avoided. The unit is small handy portable and can reach places easily.
Microcontroller AT 89S52
The micro controller used here is 89S52 is a low power, high performance CMOS 8-bit micro controller with 8K bytes of programmable flash memory. The 89S52 is the family of Intel 8051. It is powerful micro controller which provides high flexibility and cost efficient solutions to many embedded controller application.
This is like brain of the robot which operates the robot according to the user command. 40 pin Integrated Circuit and 8bit operation which receives the signals from 4 ports. It is programmed so to operate by receiving signal from RF receiver circuit through port 1.0 to port 1.4.
Gear DC Motor
A DC motor works by converting electric power into mechanical work. This is accomplished by forcing current through a coil and producing a magnetic field that spins the motor. Gear DC Motor is used to drive the robot which is connect to wheel of the robot this motor is called as gear motor because this has a specific number of RPM based on the combination of gears connected to the shaft of dc motor.
RF Receiver
433 MHz RF receiver is used having 8 pin. This receives the RF signal transmitted and converts it in to digital data signal. And these have a range of up to 100 meters with no line of sight.
Mine Detector
The mine detector is used to detect the land mines buried beneath the land. It detects the mine on its way by indicating a buzzer sound.
Wireless Camera
A camera is a device that records images, either as a still photograph or as moving images known as videos. This is used in the robot to take the video surveillance of the area. And it is transmitted using a carrier signal. On the receiving end it is converted to video signal. It has a range of 70-100Mts with no line of sight.
Battery
Rechargeable Lead acid battery is used. This is the main power supply for the whole robot provides 12 Volts and a max current of up to 1.2A.Which is further regulated to 5volts for digital circuit operation. A charger circuitry is used to charge the battery.
MAIN BOARD CIRCUIT
Figure 3.1 shows the circuit diagram that Consists of Atmel 8051 microcontroller with driver IC L293D . Port1 is connected decoder output so this port is used as input port . Port 2 is used as output port which is connected to L293D to drive four relay that control dc motor.7805 regulator used to give the regulated output to 5 volts. It is a 3 Pin device.Pin1 is input, Pin2 is GND and PIn3 is output 5volts.The operation range for 7805 is 6volt-7volt, which gives regulated output 5volts. An 11.0592MHZ crystal is connected to Pin 18 & Pin19 of microcontroller. A pair of 33pf ceramic disk capacitor is connected to crystal. Another lead of the capacitor is connected to GND. To avoid any harmonics generated during the time of oscillation and to maintain sustain oscillation for the perfect operation of microcontroller 10k register is connected to GND, another point is connected to PIn9 which is a reset pin 10muf capacitor is connected to Pin9 and other lead is connected to vcc. A high signal on this Pin makes the controller to reset. Pin 31 is connected to vcc which is an EA/VPP. When high on this Pin makes the controller to access data from internal memory. Low on this makes the access the data from external memory. Vpp is voltage pulse for programming used during the down loading HEX file to the microcontroller.