18-07-2012, 11:07 AM
UNMANNED AERIAL VEHICLE
UNMANNED AERIAL VEHICLE SYNOPSIS.docx (Size: 1.76 MB / Downloads: 76)
INTRODUCTION
The Quadcopter is a flying platform that uses four rotors. Each of the four rotors deliver an individually controllable amount of thrust. The rotors are positioned at the corners of a square. Any two adjacent rotors are contra-rotating. The Quadcopter of this project is small, electrically powered, and controls individual rotor thrusts by varying the speed of
their electric motors, rather than blade-pitch. This allows for the use of fixed-pitch propellers.
The goal of this project is to create a small, robust and autonomous flying robot that can be used both indoors and outdoors. Flying four-rotor robots are similar to helicopter. In contrast to mono-rotor system, these so-called quadcopter usually provide more sensors and more robust controller. Helicopter without any sensors or controllers can be remotely controlled by a person.
However, due to their physical instability this is not possible for quadcopter: the system needs to be continuously stabilized. A combination of gyrometers and acceleration sensors is used to determine its current state. Based on these measurements, a digital controller continuously adjusts the orientation of the platform. In such a way devices can easily be piloted by other digital systems such as a sensor network. By only controlling the pitch and the roll angles, the current position cannot be obtained. The quadcopter always hovers on top of an air cushion. Thus, any minimal measurement error or any airflow may cause a drift to a random direction. The system remains highly instable w.r.t. position maintenance. Angle correction must be permanently applied and more than on board instruments need to be used to keep the flying robot in position. The GPS module will provide the exact location of the flying robot by processing information obtained from 27 artificial satellites of UNITED STATES. This can further help in getting exact information for the calculations involved. An on-board camera will be able to record video and directly transmit to a distant personal computer from which we can know about the surrounding of our flying robot and can operate it better. The operation of this flying will be semi-autonomous. It will be able to sense the obstacles in six directions ( top, bottom, left, right, front, back ) and stay distant from those obstacles but the user solely will be responsible to operate this. This flying robot will be controlled by a remote and for that, two trans-receiver modules will be employed.
PART LIST
• PRINTED CIRCUIT BOARD ( PCB )
• MICROCONTROLLER ( PIC 18F4520 )
• TRANSRECEIVER ( RFM12B – 100 METER RANGE )
• ULTRASONIC SENSORS
• CAMERA MODULE
• GLOBAL POSITIONING MODULE ( GPS MODULE PMB 688 BUILT IN PATCH ANTENNA )
• GYROSCOPE MODULE ( 3-Axis ±100 °/Second Analog Yaw-Pitch-Roll )
• ACCELEROMETER MODULE ( DIRECTION CONTROL)
• DC BRUSHED MOTORS ( 7.5A, 12V GIVING 20000 RPM ON NO LOAD )
• PROPELLERS
• 16 X 2 LCD DISPLAY SCREEN
• 40 A,12V VOLTS POWER SUPPLY
• 12V VARIABLE POWER SUPPLY
• INTEGRATED CIRCUITS USED ( IC )
IRF 40N03 ( N CHANNEL POWER MOSFET FOR 40A POWER SUPPLY)
OPA404 ( QUAD DIFET OPERATIONAL AMPLIFIER FOR 40 A POWER SUPPLY)
IRF 7910PBF ( N CHANNEL MOSFET FOR 10A ESC )
MAX232 (TTL TO CMOS COMPATIBILITY & VICE VERSA)
7805,7812 ( VOLTAGE REGULATOR )
BSS138 ( LOGIC LEVEL CONVERTER )
• LITHIUM POLYMER BATTERY
• LITHIUM POLYMER BALANCE CHARGER NR-BLIC-03 (MAINS SUPPLY)
• LOGIC LEVEL CONVERTER CIRCUIT
• ELECTRONICS SPEED CONTROL CIRCUIT ( FOR DC MOTOR DRIVE)
• SOFTWARES
MPLAB IDE V6.5
EAGLE PCB DESIGN
ICD DEBUGGER
PART DESCRIPTION
MICROCONTROLLER ( PIC 18F4520)
PIC 18f4520 is a Microchip technology inc. product. Microchip Technology Inc. is a leading provider of microcontroller, analog, memory, flash-IP solutions, providing low disk product development, lower total system cost and faster time to market for thousands of diverse customer applications worldwide. Microchip offers outstanding technical support along with dependable delivery and quality.
PIC 18f4520 controller of Microchip tech. inc. has multiple functions. Following are the salient features of PIC 18f4520:
• 40-Pin Enhanced Flash Microcontrollers with 10-Bit A/D and Nano Watt technology.
• Power Management Features:
Run: CPU on, Peripherals on
Idle: CPU off, Peripherals on
Sleep: CPU off, Peripherals off
Ultra Low 50nA Input Leakage
Run mode Currents Down to 11 A Typical
Idle mode Currents Down to 2.5 A Typical
Sleep mode Current Down to 100 nA Typical
Timer1 Oscillator: 900 nA, 32 kHz, 2V
Watchdog Timer: 1.4 A, 2V Typical
Two-Speed Oscillator Start-up
• Flexible Oscillator Structure:
Four Crystal modes, up to 40 MHz
4x Phase Lock Loop (PLL) – Available for Crystal and Internal Oscillators
Two External RC modes, up to 4 MHz
Two External Clock modes, up to 40 MHz
Internal Oscillator Block:
- Fast wake from Sleep and Idle, 1 s typical
- 8 user - selectable frequencies, from 31 kHz to 8 MHz
- Provides a complete range of clock speeds from 31 kHz to 32 MHz when used with PLL
- User-tunable to compensate for frequency drift
Secondary Oscillator using Timer1 @ 32 kHz
Fail-Safe Clock Monitor:
- Allows for safe shutdown if peripheral clock stops
• Peripheral Highlights :
Master Synchronous Serial Port (MSSP) module
Supporting 3-Wire SPI (all 4 modes) and I2C™Master
Enhanced Addressable USART module:
-Supports RS-485, RS-232 and LIN/J2602
- RS-232 operation using internal oscillator block (no external crystal required)
- Auto-wake-up on Start bit
- Auto-Baud Detect
10-Bit, up to 13-Channel Analog-to-Digital (A/D) Converter module:
- Auto-acquisition capability
- Conversion available during Sleep
Dual Analog Comparators with Input Multiplexing
Programmable 16-Level High/Low-Voltage Detection (HLVD) module:
- Supports interrupt on High/Low-Voltage Detection
Special Microcontroller Features:
C Compiler Optimized Architecture:
- Optional extended instruction set designed to Optimize reentrant code
100,000 Erase/Write Cycle Enhanced Flash program memory typical
1,000,000 Erase/Write Cycle Data EEPROM Memory Typical
Flash/Data EEPROM Retention: 100 Years Typical
Self-Programmable under Software Control
Priority Levels for Interrupts
8 x 8 Single-Cycle Hardware Multiplier
Extended Watchdog Timer (WDT):
- Programmable period from 4 ms to 131s
Single-Supply 5V In-Circuit Serial Programming™ (ICSP™) via Two Pins
In-Circuit Debug (ICD) via Two Pins
Wide Operating Voltage Range: 2.0V to 5.5V
Programmable Brown-out Reset (BOR) with Software Enable Option
PIC 18F4520 ALSO HAS:
Program Memory of 32Kbytes flash memory with 16384 single word instruction
Data Memory has 256 bytes of EEPROM ( Electrically Erasable Programmable Read Only Memory) & Static RAM of 1536 bytes
10 Bit A/D Converter having 13 analog channels
CCP/ ECCP (PWM)
Master slave serial port for serial communication: SPI (serial peripheral interface ) & I2c (Inter Integrated Circuit)
EUSART ( Enhanced Universal Asynchronous Synchronous Receiver & Transmitter module)
4 Timer modules (Timer0, Timer1, Timer2, Timer3)
GLOBAL POSITIONING MODULE
( GPS MODULE PMB 688 BUILD IN PATCH ANTENNA )
PMB-688 FEATURES
• Built-in SIRFstarIII chipsets receivers give unparallel GPS performance and precision. 20 parallel satellite-tracking channels for fast acquisition and reacquisition
• Built-in WAAS /EGNOS Demodulator.
• Low power consumption and ultra mini size only 33x39mm.
• Built-in rechargeable battery for backup memory and RTC backup.
• Support NMEA0183 v2.2 data protocol.
• Enhanced algorithms providing superior navigation performance in urban, canyon and foliage environments.
• For Car Navigation, Marine Navigation, Fleet Management, AVL and Location-Based Services, Auto Pilot, Personal Navigation or touring devices, Tracking devices/systems and Mapping devices application.
• Include RF MMCX connector(Optional: Active Antenna)