01-12-2012, 04:30 PM
PROJECT REPORT ON A NOVEL REAR END COLLISION & ACCIDENT AVOIDANCE SYSTEM WITH DYNAMIC SPEED GOVERNOR
Accident avoidance system .pdf (Size: 2.1 MB / Downloads: 64)
ABSTRACT
Automotive vehicles are increasingly being equipped with collision avoidance and warning systems for predicting the potential collision with an external object, such as another vehicle or a pedestrian. Upon detecting a potential collision, such systems typically initiate an action to avoid the collision and/or provide a warning to the vehicle operator. This system consist of a distance-measuring system based on ultrasonic sound utilizing the PIC 16f877A microcontroller and transmits a burst of ultrasonic sound waves towards the target and then receives the corresponding echo. An ultrasonic sound sensor is used to detect the arrival of the echo to the system. The time taken for the ultrasonic burst to travel the distance from the system to the subject and back to the system is accurately measured by the microcontroller. It also provides a warning signal to the driver if the distance between vehicle and obstacle crosses a particular limit. It also monitors the speed of the vehicle and if the speed limit is exceeded it is informed to the driver. The speed limit for different class of vehicles is set by authorities at different.
INTRODUCTION
This report describes a distance-measuring system based on ultrasonic sound utilizing the PIC 16f877A microcontroller. With the help of the distance measured, the micro-controller will make the vehicle stop suddenly if the vehicle is about to hit any obstacle or any other vehicle. With the help of this technology accidents are avoided. The system transmits a burst of ultrasonic sound waves towards the target and then receives the corresponding echo. An ultrasonic sound sensor is used to detect the arrival of the echo to the system. The time taken for the ultrasonic burst to travel the distance from the system to the subject and back to the system is accurately measured by the microcontroller. Different types of vehicle speed limiters are in current use for regulating traffic especially across roads near populated areas such as hospitals, malls and schools. This project “DYNAMIC SPEED GOVERNER” is a new method by which vehicle speed is controlled externally rather than internally. The speed measurement and control is accomplished via two PIC16F877As with a RF transmitter and a receiver.
MPLAB IDE MPLAB
Integrated Development Environment (IDE) is a free, integrated toolset for the development of embedded applications employing Microchip‟s PIC and dsPIC microcontrollers. MPLAB IDE runs as a 32-bit application on MS Windows, is easy to use and includes a host of free software components for fast application development and supercharged debugging. MPLAB IDE also serves as a single, unified graphical user interface for additional Microchip and third party software and hardware development tools. Moving between tools is a snap, and upgrading from the free software simulator to hardware debug and programming tools is done in a flash because MPLAB IDE has the same user interface for all tools. A development system for embedded controllers is a system of programs running on a desktop PC to help write, edit, debug and program code- the intelligence of embedded systems applications in to a microcontroller. MPLAB IDE, runs on a PC and contains all the components needed to design and deploy embedded systems applications. MPLAB IDE Programmer‟s Editor helps write correct code with the language tools of choice. The editor is aware of the assembler and compiler programming constructs and automatically “color-keys” the source code to help ensure it is syntactically correct. The Project Manager enables you to organize the various files used in your application source files,processor description header files and library files.
CCS C COMPILER
The compiler contains Standard C operators and built in libraries that are specific to the PIC registers. Access to hardware features from C. The compiler includes built-in functions to access the PIC microcontroller hardware such as READ_ADC to read a value from the A/D converter. Discrete I/O is handled by describing the port characteristics in a PRAGMA. Functions such as INPUT and OUTPUT_HIGH will properly maintain the tri-state registers. Variables including structures may be directly mapped to memory such as I/O ports to best represent the hardware structure in C. The microcontroller clock speed may be specified in a PRAGMA to permit built in functions to delay for a given number of microseconds or milliseconds. Serial I/O functions allow standard functions such as GETC and PRINTF to be used for RS-232 like I/O. The compiler runs under Windows 95, 98, ME, NT4, 2000, XP, Vista or Linux. It outputs hex and debug files that are selectable and compatible with popular emulators and programmers including the MPLAB IDE for source level debugging.
MICROCONTROLLER -
PIC 16F877A The microcontroller is a set of digital logic circuits integrated on a single silicon „chip‟ whose connections and behavior can be specified and later alter when required, by the program in its memory. The great advantage of this is that in order to change the circuit‟s structure and operation, all that is needed is a change in the program very little, if any, circuit hardware modifications are necessary. The microcontroller unit used here is a PIC16f877A .The core controller is a mid-range family having a built-in SPI master. 16F877A have enough I/O lines for current need. It is capable of initiating all intersystem communications. The master controller controls each functions of the system with a supporting device. Also responsible for reception of commands from the host and taking necessary actions. PIC16F877A is an 8-bit, fully static, EPROM/EPROM/ROM-based CMOS microcontroller. It employs RISC architecture with only 35 word/single cycle instructions. All these instructions are single cycle (1ms) expect for program branches which takes two cycles. The PIC16f877A products are supported by a full featured macro assembler, a software simulator, „C‟ compiler etc.