27-10-2016, 03:25 PM
MICROCONTROLLER BASED ANTENNA POSITIONING SYSTEM FOR MISSILE TRACKING.docx (Size: 198.56 KB / Downloads: 7)
ABSTRACT
Today in the twenty first century the Missile technology is rapidly developing with the advancement of the science. In today’s world all types of missiles uses the principle of combustion for its movement. So, until the new technology initiates the tracking of the missile is possible. These missiles can be tracked with the help of Radar, microwave sensing, etc. These equipment’s are highly advanced and too costly for every developing country to purchase and implement it for their safety. In order to make its design simple, easy to install and to achieve its efficiency, keeping this in background the project has been designed in such a manner that the Missile is detected.
Missile locating and tracking is a critical activity during flight trial. Missile tracking is carried out by a pole mount tracking pedestal system. Apart from that UAV carried, compact and light weight telemetry pedestal system is required for low flight trajectory flying object. An Embedded system for remote antenna positioning and control is designed to address this requirement. A Microcontroller had been interfaced to a stepper motor for antenna positioning and a feedback control is achieved using a potentiometer. Subsequently, graphical user interface(GUI) is designed for monitor and control operation.
The microcontroller used is ATmega 328, Arduinos board and software used is C language and Labview for GUI. Hardware and software has been integrated as a single unit tailored for missile tracking. Finally, designed system is tested through simulation.
INTRODUCTION
About the organization:
Defense research and development laboratory (DRDL) is one of the premier laboratories
under defense research and development organization (DRDO).
DRDL involves in development of state-of-the-art weapon delivery systems if national
interest. Directorate of Instrumentation(DOI) is one of the key Technology Directorates
of DRDL.
Under DOI there are three divisions:-
a)GID(Ground Instrumentation Division)
b)VIEW(Visual Imaging and Editing Wing)
c)RSD(Range System Division)
DOI is responsible for providing instrumentation support during static and flight trials
of different propulsion systems and their related subsystems.
DIRECTORATE OF INSTRUMENTATION (DOI):
Directorate of instrumentation (DOI) is one of the important directorates of Defence-
Research and Development Laboratory (DRDL) to take care of various propulsion
instrumentation, visual instrumentation and telemetry requirement for the development
of missile systems. Ground Instrumentation Division (GID) is responsible for
propulsion instrumentation during static testing of different propulsion system and
outstation activities (static tests in other labs and flight test).
During the test, physical parameters like pressure, thrust ,temperature, flow and
even are required to be measured ,monitored and acquired .The acquisition to be performed
at remote location for safety purpose as the propulsion system consists of high
explosive materials . The instrumentation chain consists of respective transducers,
signal conditioners and data acquisition systems. The data are transmitted by means of
signal cables from sensors to the acquisition systems through signal conditioners.
During the transmission of data, the data may get corrupted by noise (which appears
from different sources) and distorts the useful information related to the physical.
This data need to be processed & useful information related to the physical parameters
are to be retrieved.
INTRODUCTION OF PROJECT:
1.INTRODUCTION:
Evaluation of medium and long range missiles requires physical parameters of sub-systems as well as navigational data acquired and recorded through telemetry. The instruments to be deployed for adequate coverage of the flight are ensured during launch, mid-course and terminal phases of flight path. The missile tracking systems deployed at the launch site ensure data reception requirements of flight path.
A missile tracking pedestal system is developed for tracking purpose. The regular systems are very bulky and difficult to be deployed. So, a Portable Pedestal System is developed in which two antennas are used depending on the range of the signal. The portable system for tracking applications is a solution which gathers in a portable computer full functionalities and performances. Based on Data acquisition software, Portable Pedestal System is an essential tool for the test engineer to run tests on site. Portable Pedestal System acquires, analyzes and visualizes data.
The antenna is rotated according to the Look Angles provided by Integrated Test Range. The update rate of the system is 10 Hz. The S-Band of the electromagnetic spectrum is used for transmitting the telemetry signal. This portable pedestal system can be used in various applications such as:
1. Missile applications
2. J.A.V Applications
3. Aircraft / Flight testing
4. Space.
1.1Objective:
The objective of our project is to develop a pedestal system at a low cost for tracking the missile.
1.2 Previous System:
The previous systems used for locating and tracking missiles, are highly advanced, complex and too costly to purchase and implement. To make its design simple, easy to install and to achieve its efficiency, keeping this in background the project has been designed.
1.3 Present System:
The present system we are preparing is a simple and low cost pedestal system which can reach the accuracy levels of the previous systems. In this system we use both hardware and software. We use Arduino Uno board in which the controller used is ATmega 328, a bipolar stepper motor, a potentiometer for feedback, antennas for tracking.
In the next chapters we discuss in detail about the working of every component used and how a missile is tracked and how the data obtained is analyzed.
SYSTEM OVERVIEW
2.1 Block Diagram:
The pedestal system consists of a control and command system, a microcontroller, a stepper motor, a stepper motor driver, antennas and a potentiometer for feedback. A control and command system is normally a computer system from which the commands are given about the missile trajectory. This data is fed into the microcontroller which in turn turns on the stepper motor driver. This driver rotates the stepper motor to the required direction for the specified angles. The potentiometer in turn rotates and changes the voltage. The potentiometer changes +0.5 volts for every one step clockwise rotation and -0.5 for every one step anticlockwise rotation. The voltages changes are measured noted and graph is drawn and it is compared with the expected graph.
Before this the antennas must be set to true north position. The true north position is set where the potentiometer reads the voltage of 2.5v. When the feedback voltage of potentiometer is not 2.5v then the control and command system gives the command to rotate the motor in order to set the potentiometer voltage to 2.5v and hence the antennas will be set to true north position. Then the required trajectory is fed and then the missile is tracked.
2.2.1.1 ATMEGA 328:
Microcontroller used in this pedestal system is ATMEGA 328. Atmel ATmega328 microcontrollers are high-performance RISC-based devices that combine 32KB ISP Flash memory with read-while-write capabilities, 1KB EEPROM, 2KB SRAM, 23 general-purpose I/O lines, 32 general-purpose working registers, serial programmable USART, and more. By executing powerful instructions in a single clock cycle, theATmega328P achieves throughputs approaching 1 MIPS per MHz allowing the system designed to optimize power consumption versus processing speed.
2.2.2 Stepper motor:
A stepper motor is an electromechanical device which converts electrical pulses into discrete mechanical movements. The shaft or spindle of a stepper motor rotates in discrete step increments when electrical command pulses are applied to it in the proper sequence. The motors rotation has several direct relationships to these applied input pulses. The sequence of the applied pulses is directly related to the direction of motor shafts rotation. The speed of the motor shafts rotation is directly related to the frequency of the input pulses and the length of rotation is directly related to the number of input pulses applied.The stepper motor has the permanent magnet as rotor and they have multiple coils that are organized in groups called "phases" as stator part. By energizing each phase in sequence, the motor will rotate one step at a time.
Stepper motors are of two types.
1. Unipolar stepper motors and
2 Bipolar stepper motors.
2.2.3 Stepper Driver:
Motors require more current than the microcontroller pin can typically generate. This may be a switch which can accept a small current, amplify it and generate a large current which further drives a motor. This entire process is done by what is known as a Motor Driver. A motor driver is a circuit that not only drives the motor, but also controls its direction. The most common and clever design is an H-bridge circuit where transistors are arranged in a shape that resembles alphabet ‘H’. To drive a stepper motor we need a dual H-bridge circuit. So, here we have used a L298 IC as a stepper motor driver.
2.2.3.1 L298:
The L298 is an integrated monolithic circuit. It is a high voltage, high current dual full-bridge driver. Two enable inputs are provided to enable or disable the device independently of the input signals.
L298 has 15 pins. They are, 2 are current sinking pins, 2 enable pins, 2 supply voltage pins in which one is motor voltage supply to which we connect the voltage required to run the motor and it is given from DC power supply and the other is the voltage supply pin of L298, the other 4 pins are input pins which are connected to Arduino, the other 4 pins are output pins which are connected to stepper motor.
Potentiometer:
In this system we are using potentiometer for feedback. A potentiometer is a manually adjustable electrical resistor that uses three terminals.Here among the three terminals of potentiometer, one is connected to power supply the other to ground and the middle terminal is connected to the analog pin of the Arduino Uno. Potentiometer is used to vary the analog voltage of the analog pin of the Arduino. The potentiometer must be set at a point where the analog voltage is 2.50 volts and is connected to Arduino to which the motor driver (L298) and to which bipolar stepper motor is connected. The voltage can be changed by turning the potentiometer. If we increase the voltage, the motor rotates clockwise and if we decrease the voltage the motor rotates in the anticlockwise.
HARDWARE DESCRIPTION
3.1 Power Supply:
3.1.1 LS (Logic Supply):
It consists of two pins one is +ve and another is –ve. A battery or an AC adaptor can be connected here to provide power supply to the mother board it provides regulated power supply to all the peripherals present in the mother board and also to the external peripherals connected to the motherboard through a voltage regulator. The DC voltage provided to this terminal should be lies in between 6 to 16 volt. To use the supply connected in LS pin the power switch should be toggled towards “MP” (Main power).
3.1.2 DS (Driving Supply):
It consists of two pins one is +ve and another is -ve. It is basically used to provide a separate high current power supply to the Motors. For operating DC motors you may provide here a Power supply of 5 to 40 volt. For operating a servo motor you may suppose to provide any suitable power supply as per the requirement of your motors (mostly servos works at 4.5 to 6 volt). Power from this pins are directly goes to the driving supply of the motor driver and to the supply pins of PortB if PTOG switch is toggled towards EXT.
3.1.3 J1 (Jumper 1):
It is a simple jumper which can be use to use a single power supply for DS and LS. If you put here a jumper then you have to provide supply only on DC or LS and your board will get both the power supply.
3.1.4 USB socket:
It is basically used for USB communication with the PC. It also provides necessary logic supply to the motherboard. In order to use the USB supply the POWER switch should be toggled towards UP (USB power). When using the USB power some precautions should be taken such as any heavy load should not be connected to the board directly and don’t use the J1.
3.2 Arduino UNO:
An Arduino is an open-source microcontroller development board. We can connect different components to arduino which can be run by just uploading a program onto the arduino board.