Remote Controlled Monitoring Robot

The idea of the project evolved with a fantasy to see the places we wish to see at will. In this project this idea is realized at our fingertips. The project is done to create a version of spying robot that can enable us to observe the place of our interest. The size of the robot also aids it to be used as a spy robot. Thus to create the robot, we should be able to manipulate its path when necessary. To realize all that, a control unit is required .In this control units DTMF signal is used. Using these signals encoding is done and signal is sent through the transmitter. In the receiver end these received signals are decoded and given as input to drive the motor. This will help us to manipulate the robot in the manner we want. A video transmitter mounted on top of the robot helps us to see the path of motion.

The reason behind manual control of the robot is that it will not be lost owing to absence of human involvement. If not for long range applications it can be used as a spy robot within short distances. Other than as spy robot this robot can be used as a surveillance robot. This will be of great boon in locations which are not accessible for humans. But our interests can be prioritized by the means of controlling of the robot. By advanced technological modifications these robots can be made to move through air and water. This can improve the scope of this robot

In the 21st century every country’s paramount interest is self protection. For that reason the need for defense research has grown by monstrous proportions. Spy network developments occupy a lion’s share of effort behind defense research. Unmanned surveillance network has been a field of interest for decades. The advantages are that, on one hand it provides reliable information while on the other hand it negates a need of direct human involvement .The information is reliable since all the transmitted information can be observed on the monitor. Loss of human life can also be avoided.

Another problem faced by unmanned flying objects is that they can be detected by means of radars. This anomaly is also rectified when we create an unmanned monitoring robot that traverses the distance through ground.

CONTROL

This section consists of a controller unit that controls the motion and direction of the robot. This control is a part of the encoder that converts the control input into DTMF. The control section determines the direction of motion of the robot. For controlling the robot, 8 signals are required whereby the robot can move in all directions.

ENCODER

This section is the initial stage where the control of the robot is done. Using DTMF signals 12 frequency combinations are possible, of which 8 are used. These signals are so designated that each combination decides the motion in the corresponding direction. The encoder IC used is UM91215B.

TRANSMITTER

The signals that are encoded is sent using the transmitter MDT433. It is a complete RF transmitter wireless module. This transmitter works under the frequency of 433.92MHz. This is an AM/ASK transmitter module. The advantage of this transmitter is the low power consumption and wide operating voltage. This makes the transmitter module ideal for battery operated low power applications. The small size of this module makes it compatible with the cabinet.

RECEIVER

Receiver module is MDR433. This RF receiver module helps to design their application in remote control in quick manner. The biggest advantage of this compact module is its high sensitivity and immunity to other radio interferences. This quality makes this module highly stable and reliable even in worst environmental conditions.

The signals transmitted by the transmitter module are in an encoded form. Since this needs to be decoded a decoder IC MT8870D is used. This IC is a complete DTMF receiver integrating both band split filter and digital decoder function. The filter section uses switched capacitor techniques for high and low group filters, the decoder uses digital counting techniques to detect and decode all 16 DTMF tone pairs into a 4 bit code.

MOTOR DRIVER

The motor driver IC is L293D.This IC drives the two motors of the robot which aids it in motion in all the directions. The direction is decided by the output of the decoder i.e. the decoded signals. This signals are ANDed and given to the input of the motor driver in the required manner. The output of L293D is given as input of motor. Thus, this will help us to move the robot in accordance with the encoded signal.

The L293 is the quad push pull drivers capable of delivering output current of 1mA per channel respectively. A separate supply input is provided for the logic so that it may be run off a very low voltage to reduce dissipation. The biggest advantages of this IC are the high noise immunity and over-temperature protection.

Figure shows the schematic diagram of the TV Transmitter circuit. Video signals input at jack J1 are first terminated by resistor R6 and coupled through capacitor C1 to clamping-diode D1. The clamping forces the sync pulses to a fixed DC level to reduce blooming effects.

Potentiometer R3 is used to set the gain of the video signal; its effect is similar to that of the contrast control on a TV set. Bias-control R7 can be used to adjust the black level of the picture so that some level of signal is transmitted, even for a totally dark picture. That way, a TV receiver can maintain proper sync. As we'll get to later, potentiometers R3 and R7 are cross adjusted for the best all-around performance.

RF-transformer T1 and its internal capacitor form the tank circuit of a Hartley oscillator that's tuned to 4.5 megahertz. Audio signals input at J2 are coupled to the base of Q3 via C2 and R4: the audio signal modulates the base signal of Q3 to form an audio sub carrier that‚s 4.5-megahertz higher than the video-carrier frequency. The FM modulated sub carrier is applied to the modulator section through C5 and R9. Resistor R9 adjusts the level of the sub carrier with respect to the video signal.

Transistors Q1 and Q2 amplitude modulate the video and audio signals onto an RF-carrier signal. The operating frequency is set by coil L4, which is 3.5 turns of 24- gauge enameled wire on a form containing a standard ferrite slug. That coil is part of a Colpitts tank circuit also containing C7 and C9. The tank circuit forms Q4's feedback network, so Q4 oscillates at the set frequency.

The RF output from the oscillator section is amplified by Q5 and Q6, whose supply voltage comes from the modulator section. Antenna matching and low-pass filtering is performed by C12, C13, and L1. Resistor R12 is optional; it is added to help match the output signal to any kind of antenna.