The intelligent wireless video camera described in this paper is designed using wireless video monitoring system, for detecting the presence of a person who is inside the restricted zone. This type of automatic wireless video monitors is quite suitable for the isolated restricted zones, where the tight security is required.
The principle of remote sensing is utilized in this, to detect the presence of any person who is very near to reference point with in the zone.
A video camera collects the images from the reference points and then converts into electronic signals. The collected images are converted from visible light into invisible
electronic signals inside a solid-state imager. These signals are transmitted to the monitor,
In this paper for the demonstration purpose three reference points are taken. Each reference point is arranged with two infrared LED’s and one lamp. This arrangement is made to detect the presence of a person who is near the reference point. The reference point is nothing but restricted area, when any person comes near to any reference point, then immediately that particular reference point output will become high and this high signal is fed to the computer. Now the computer energizes that particular reference point lamp and rotates the video camera towards that reference point for collecting the images at that particular reference point. To rotate the video camera towards interrupted reference point, stepper motor is used.
The present wireless video camera described in this is designed using wireless video monitoring system, for detecting the presence of a person who is inside the restricted zone. This type of automatic wireless video monitors is quite suitable for the isolated restricted zones, where the tight security is required.
Once upon a time much importance is not given for the security system. But as we see today lot of terrorism has grown up across the country and need has aroused to develop different types of security systems for various applications to safe guard the zones of various types like, military zones, railway yards, scrap yards, borders etc., this kind of automatic video monitoring systems can be installed at indo-pak borders, where the terrorists are crossing borders. In fact our country is spending lot of its revenue to safe guard the borders. By installing this type of security systems everywhere at critical points, lot of revenue can be saved by minimizing the manpower.
Basic operational principle:
The video surveillance unit is designed for the widest possible viewing range and portability. The unit consists of a Stepper Motor, which drives the camera towards reference points automatically by the computer and a transmitter
transmits the images collected by the camera to a distant end. Thus a automatic controlled wireless camera is very useful for surveillance of places where the particular location makes it inconvenient or impractical for a wired operation of the unit. The robotic action made by the stepper motor is attached to the camera allows surveillance of maximum area with one single camera. Such setup can be very flexible to the user and can save valuable company resources. There are several types of security systems existed in the Market; one of the most common security systems is CCTV (Closed Circuit Television). The CCTV consists Video Surveillance Camera used as security-monitoring device plays a major roll in security systems. One reason for this is the fact that a picture is worth then a thousand words. This is especially true in a court of law where an eyewitness is required who can place the criminal at the scene of a crime.
CCTV systems are also helpful in the residential security Market. They allow homeowners to see their callers, thus establishing their identity before they open an outside entrance door. This is an important feature too, because other wise, they might open their door to a criminal.
The Infrared sensing circuit consists of two infrared LED’s for transmitting the signal as well as receiving the signal. The signal transmitted by the transmitting LED omits the signal in a line like laser beam, the radiated signal from the transmitting LED is invisible and harmless. Whenever the human body interrupts the transmitting signal, there the signal is reflected and this reflected signal is received by the infrared receiving LED.
INFRARED TRANSMITTER / RECEIVER SECTION:
This section is designed for detecting the presence of a person who is inside the restricted zone within the range. It is basically an infrared proximity detection system. Here high efficiency IR-LED is driven by PNP Transistor SK100 with a modulating frequency of about 10KHz. This frequency is available from Pin 5 of LM 567 IC (versatile PLL tone decoder IC). The 47W resistor connected in series with the IR LED limits the IR-LED current.
The basic function of the detector circuit is by radiating energy into space through IR LED and detecting the echo signal reflected from an object. The reflected energy that is returned to the receiving LED indicates the presence of a person who is within the range. A portion of the transmitted energy is intercepted by the target and re-radiated in many directions. The radiation directed back towards the system is collected by the receiving LED causes to produce a high signal at Pin No.8 of LM567 IC. The output of the receiver is fed to the computer. Whenever the computer receives a high signal from the reference point, the computer drives the stepper motor through the driving transistors and rotates the motor towards that particular reference point. Three similar circuits are designed for the three different reference points.
The computer is playing a major role in this .The main function of the computer is to identify the interruption made by the person, where exactly the signal is interrupted, at which reference point identifying the point and displays the information on the screen. The other major function of the computer is to drive the stepper motor. This block is also responsible for identifying the reference point. Here any normal configuration computer can be employed. The software program defining the operations for the computer is written in ‘C’ language.
The output of the obstacle sensor is fed to the computer through the parallel port. The original purpose of Parallel port was to enable communication between a PC and a peripheral. Another use that has become very popular is transferring information or receiving the information. In this project work the received information from the detector circuit is used to drive the motor. Which is useful for the system for identifying the interrupted reference point. With the help of associated software written in ‘C’ language the received information can be displayed on computer screen.
A computer is an electronic device, which processes information under the control of a set of instructions called program. It has the ability to accept the data, execute the program, and perform mathematical and logical operations on data. The result of the operations can be reported through output. Infact, a computer is a complete system in itself. The computer as a system is a combination of Hardware and Software components that jointly offer the necessary services to the user.
The computer reads the data received through parallel port and can store the data; the same data will be displayed on computer screen. The program contains instruction about what has to be done with the data. The CPU executes the programs stored in the main memory by performing fetch instruction from memory and right data either to a memory location or on an output device. The main components of the CPU are, ALU (Arithmetic and Logic Unit), CU (Control Unit), and a set of registers. The control unit is responsible for the moment of data and instructions in and out of the memory and CPU. It is also responsible for the decoding of an instruction and determining as to what is desired by the same. The complete electronic Hardware is interfaced with parallel port.
HOW THE COMPUTER DRIVES THE STEPPER MOTOR
To drive the stepper motor in both the directions (clockwise or anticlockwise) the system is programmed to produce the pulses in a sequence at four different outputs, these sequential programmed outputs energizes the motor windings one after another in a sequence. To drive the motor in clockwise, the sequence starts from top to bottom, similarly to drive the motor in anti-clockwise the sequence starts from the bottom to top. Like wise the motor rotates in both the directions.
The output of the computer through parallel port is used to drive the switching transistors; finally these switching transistors drive the stepper motor. These transistors provide the required current to energize the motor. The stepper motor used in this project work is capable to drive up to 3Kg loads, i.e., the holding torque is 3Kg.
The output of the computer is also used to drive the three relays and one buzzer. Whenever any human body interrupts any reference point, the computer energizes the alarm at the same time the computer energize the corresponding relay also. These relay contacts are used to energize the three different lamps corresponds to the three reference points independently. The circuit diagram of relays and buzzer driven by the computer is shown below.
Stepper Motor Drive Circuit:
The stepper motor used in this is having four windings and these windings are energized one after another in a sequence according to the code produced by the computer through motor drive circuit. This motor rotates in step wise and the step angle is 1.80. Varying the pulse rate can vary the speed of the motor. The pulses are produced by the computer can be controlled through the program by which motor speed can be varied. The stepper motor used in this project work is capable to drive up to 3kg load.
Each reference point is arranged with two infrared sensors and both the sensors are arranged side by side within the distance of one inch approximately and both are directed towards the space with the zone. The energization sequence for the forward and backward movements of the stepper motor is fed from computer with the help of software written in ‘C’ language. The ratings of the motor employed are 12V dc 4-coil. The driving circuit of the motor is designed using BC 547 (low power Transistor) and 2N5296 (Medium power Transistor). These two transistors are configured in emitter following mode for amplifying the current rating. The motor winding when it is energized, it consumes 350 mA approximately.