Every day many lives are lost due to the cause of the road accidents .The main causes of the accidents are due to many reasons such as carelessness of the driver, poor road infrastructure, and also due to the environmental conditions. These accidents are either intentional or actual accidents. So the vehicles running on the roads should adopt electronic systems which provide the details of before, during and after the crash accidents. The best solution to this situation is intelligent system which helps to find the way out to solve the problems.
The intelligent system consists of two sections. The first section detects the information which relates to before, during and after the road accident. The second section is to present the details to the user in an easy way. In the first section we use various components and sensors. The second section comprises of microcontroller which stores the parameter details before the crash by programming in Embedded C language. This program helps in not only recording but also retrieving the data from microcontroller memory to the LCD to display in it. Various researches are done to understand what are the main causes of the accidents based on that what type of sensors and components has to be installed in the project. The following are considered as important data that is needed after the accident: Belt status, Brake status, Alcohol sensor, Temperature sensor, Eye blink sensor, Accident detection sensor, Electrodes for sensing the road condition wet or dry and Global Positioning System (GPS) to collect location data, etc. The hardware part collects the status of the sensors and stores it in the EEPROM.
. Earlier whenever the accidents occurred the police officers investigated them by taking the information from the surrounding people. So since the exact proof is not found the real culprits escaped and many cases are closed which led to injustice to the victims. Without proper information some of the innocent people got jailed and also got penalised. Many insurance companies didn’t sanctioned loans because there is no exact proof of the accidents. In order to overcome all these problems the intelligent system plays a major role which provides the exact information regarding the accidents. The main objective of the system is whenever the accident occurs it stores the parameter details which help to find the real culprit within a short period of time and provide justice to the victims. This information also helps to find whether the accident is intentional or real accident.
In this project work two micro-controllers AT89C52 are used which belongs to 8051 family with 40 pins where out of these pins 32 pins are used as general purpose input and out pins. These two micro-controllers are placed one at transmitter section and other at the receiver section. It contains 8-bit In-system programmable flash memory which allows programming or reprogramming the flash memory soldered in target PCB board and also contains the 256 bytes of RAM which stores the data temporarily.
Micro-controller’s works as per the program code which is written with in it internally. The program which is written can read and store the data received from the components or sensors connected to it. According to the data received information the controllers displays the information by using liquid crystal display (LCD).
The micro-controllers are also called “Embedded controller”. The name embedded microcontroller defines that the micro-controllers are embedded with some other devices. Micro-controllers can perform only one specific task and runs only one specific program. These micro-controllers are low power devices for instance the battery operated micro-controllers consumes 50mw. A micro-controller has an input device and control data which is not used often and display for output. In this project the control data is used to control the relays and also display section to display output. The micro-controller holds input from the device from which it is controlling and then controls the device by sending signals to different components in the device.
The program is prepared in assembly or embedded C and according to that flowchart is prepared; a step by step approach is implemented while preparing the program. The major interfacing devices to the controller are GPS, WIFI, EEPROM and LCD. The details of these interfacing devices are provided individually in the functional description of the project work. The entire circuit is designed to operate at two different DC levels, i.e. +12V and +5V, these two voltages are derived directly from mains using step-down transformer. Complete description of this power supply unit including its circuit diagram and datasheets are provided in the further chapters. As the WIFI and GPS are also playing a major role in this project work, the following is the introduction of these technologies.
The combination of microcontrollers and Wi-Fi modem working together can create tremendous changes in the technology, with the advancement of technology particularly in the field of energy management systems, all the activities right from the basic needs to the complexity can be achieved
The acronym of Wi-Fi is wireless fidelity. Wi-Fi is a wireless technology combines with hardware, software to exchange and make use of the information. Earlier people faced many problems due to wired technology like climatic change which resulted no proper sending and receiving of information but these wireless technology overcome this problem. The people has to sit in front of the computers due to wired communication but now as technology enhanced in recent years the Wi-Fi provided a wireless communication which we can send and receive information easily.
The Wi-Fi is “A definition of small-range connections between mobile phones, digital cameras, digital watches and other mobile devices. It embraced not only in phones, cameras, watches but also in healthcare, automotive industry etc. It is an excellent technology for digital communication. It provides different data bit rates for desired purposes like voice or message. The 802.11n works on 2.4GHz and 5GHz bands. But it works rarely on 5GHz band because it takes maximum data rate 54 Mbit/s to 600 Mbit/s for its operation. By using all of these Wi-Fi related devices lead to the development of smart home where all the devices are connected, shared information easily.
Fig: Wireless Fidelity (Wi-Fi)
INTRODUCTION TO Wi-Fi (802.11):
The IEEE 802.11 specification is a global quality which explains the features of a wireless local area network (WLAN). The title Wi-Fi correlates with the name of the certification stated by the Wi-Fi alliance, earlier WECA (Wireless Ethernet Compatibility Alliance), ensures well suited between hardware devices that use the 802.11 standard.
Wi-Fi creates high-speed wireless local network. In local area network the association between the computers should not be too far from the access point. It provides high speed connections(11 Mbps or greater) to devices located within general 20m-50m indoors or within several hundred meters outdoors.
There are seven open system interconnection layers out of these two layers are held by the 802.11 for wireless connection that uses electromagnetic waves.
Physical layer: – The physical layer sends and receives the information in its basic form that is bit-level. It comprises of three types of information encoding which are Direct-sequence spread spectrum, Frequency hopping spread spectrum and infrared spectrum.
Data link layer: – The data link layer provides node to node delivery of data which is reliable. It contains Logical link control (LLC) as topper sub-layer and Media access control (MAC) as downer sub-layer. The logical link layer is used for flow control and media access control for framing, de framing, and collision resolution.
Fig: IEEE 802.11 OSI Model
WIRELESS TECHNOLOGY COMPARISION CHART:
The comparison chart of different wireless technologies is as show below:
Table: comparison of wireless technologies
GPS (GLOBAL POSITIONING SYSTEM):
Global positioning system is used to give information about precise location or position on the earth. It is used in even rough areas, dangerous locations like forests as a road indicator. Whenever a person goes to unknown locations and lost their way these GPS helps to find them the exact location of where they are and also makes them to reach to their destination safely by giving the details of their path.
The Global positioning system as the name suggests it gives about details of any location or position on the earth comprises of 24 satellites which are continuously orbiting around the earth in different positions at 11,000 nautical miles which is approximately equal to 20,200kms over the earth. Since these 24 satellites are orbiting around the earth they are placed at 6 different orbital planes with a 55 degree inclination. Based on these satellites we are getting the information regarding the locations or positions on the earth.
GPS ELEMENTS: The GPS system partitioned in to three segments.
• SPACE SEGMENT
• USER SEGMENT
• CONTROL SEGMENT
Fig: GPS Elements
The space segment consists of network satellites. The Global positioning system as the name suggests it gives about details of any location or position on the earth comprises of 24 satellites which are continuously orbiting around the earth in different positions at 11,000 nautical miles which is approximately equal to 20,200kms over the earth. For one orbit around the earth it takes 12hours. Each satellite contains a precise clock to give the information at a rate of 3 nanoseconds.
Fig: Space segment
. As the pilot fly, the GPS receiver continuously calculates the current position and display the correct position / heading. The GPS unit listens to the satellite’s signal and measure the time between the satellites transmission and receipt of the signal. In order to compute the location of the GPS receiver the satellites are divided in triangles. GPS receiver should see at least four satellites to calculate a three dimensional position not only latitude and Longitude, but altitude as well.
Fig: User segment
The control Segment of GPS consists of Master control station which consists of one station it is liable for overall management of the remote monitoring and transmission sites and Monitor station which contains the four stations Every monitor stations examine the exact altitude, position, speed, and overall of the orbiting of satellites.
Fig: Control segment
Generally whenever an accident occurred the police officers used to investigate the cases by finding clues and the information taken from the public. There is no immediate medication to the victims which result the loss of many lives. Now a day as the technology is improving in all fields hence it is desirable to provide them with an electronic system which overcomes the above problems. This electronic system can be used in any vehicle. It helps to find the exact reason of the accident which helps police officers and whenever accident caused it sends information to the nearby hospitals for immediate medication.
ACCIDENT DETECTION SYSTEM: –
The accident detection system plays an important role in finding the type of the accident. There may be different types of accidents such as accidents caused by the other people intentionally, due to carelessness of the driver like he drives car watching sideways, due to health problems like heart attacks, due to drunk and driving, due to climatic conditions like in rainy seasons the roads become slippery due to that reason there may be chances of accidents etc. By using this accident detection system we can detect the accident other than predicting it. There are three accident detection systems available now a day’s which are discussed below.
• Manual detection system
• Driver initiated detection system
• Automatic detection system
MANUAL DETECTION SYSTEM:
In this method, accident is detected from:
? motorist report
? transportation department
? public crews report
? aerial surveillance
? Close circuit camera surveillance.
It shows that the information about the accidents are taken from the witnessed people and from clues which are inaccurate. The major drawback of this type of detection system is that someone has to witness the incident if not there will be no information regarding the accident and the cases are closed because of no evidence which caused injustice to many victims. Moreover, there are delays and incorrect due to the expression problem of the onlookers. Because even though some people know the culprit they used to hide because of the fear.
DRIVER INITIATED DETECTION SYSTEM:
Driver initiated incident detection system has upper hand which includes the immediate reaction, more incident information etc. Even though it has more advantages it has some disadvantages also because whatever the information given by the driver will be accurate or may be inaccurate. Because if he is the culprit he tries to escape from the case so he argues that he didn’t any wrong because of this reason the innocent people can be jailed or got penalised. However, with the severity of the accident, driver may not be able to report the accident details at all.
AUTOMATIC DETECTION SYSTEM:
Automatic technology took an important part in our day to day life. Other than using manual devices where the user has to put the data in by hand since it is time taking process now people are depending on automatic devices which require less human work. These automatic detection systems make use of technologies such as GPS, WI-FI, different sensor etc. The Global Positioning System (GPS) is used to find the exact location or position on the earth. By using this GPS we can find the exact location of the accident. By using the Wi-Fi module we can send the accident information to the connected devices which results immediate action by the received person. The usage of different sensors gives the information based on the type of sensors used in the vehicle.
The functional description of the project work is explained in this chapter. For better understanding, the total module is divided into various blocks and each block explanation is provided here. The diagrams (block diagram and circuit diagram) of this project work are provided in the next chapter. The following is the description of the overall function or operation of the project work.
The project work is demonstrated individually for showing all the parameter variations individually. The important features explained in the introduction are explained in detail in this chapter. The description is as follows:
AUTO COLLISION DETECTION:
This is used to detect the collision of the vehicle and automatically transmit the location data read by GPS through WIFI to the control station or the concern person. A small push button type limit switch is connected to the controller on the vehicle for demonstration purpose. By pressing of the limit switch, the controller identifies the collision and reads the GPS co-ordinate (latitude ; longitude) values which will be fed to the WIFI modem to send information to the control station. Thus instant help can be obtained and immediate medications to the victims are provided. At the same time, all the other parameters data will be stored in the EEPROM interfaced to the control unit.
This is used for the seat belt condition whether it is put ON or not. The magnetic switch used in this project work is assembled in a glass container, when the heavy magnet is brought near to this magnetic switch; the contact of the switch gets closed automatically due to the magnetism. Magnetism is the process of proving the force of the magnet to the objects that produces field which either attract or repel other objects. In this project work one such magnetic switch is to be used and is to be installed in the seat belt clip mechanism. This magnetic switch helps to find out whether the driver is driving the car by wearing seat belt. It is mandatory to wear the seat belt while driving because if accident occurs it will save the life.
MEASURING OF TEMPERATURE:
For measuring the temperature of the body, a temperature sensor LM 35 is used. The LM35 are accurate combined circuit temperature sensor, whose output voltage is linearly proportional to the Celsius temperature. It can be worked with single supply or terminal power supplies. It draws only 60 µA from its power supply which results the low self heating. The LM35 is operated at a temperature range over a -55° to +150°C. The LM35 doesn’t need any exterior calibration provide typical exactness of ±1.4°C at room temperature and ±3.4°C over a full -55 to +150°C temperature range.
The output from the temperature sensor is fed to the Op-Amp LM 324. Description about this Op-Amp is provided in the alcohol sensing circuit. The cut off temperature value is set at the reference pin of the Op-Amp and the sensor input is fed to the other pin of the Op-Amp. Now the Op-Amp will compare the input temperature value with the cut off value set as the reference value and will provide a high signal to the controller when the value exceed the cut off value indicating high temperature to the driver.
EYE BLINK SENSOR:
The block is designed using IR Sensors. The eye blink-sensing block is designed with LM567 IC, this is a tone decoder IC, and also it generates tone frequency. The sensing block is designed with infrared sensors; a set of IR sensors are used as IR signal transmitting LED and IR signal receiving LED. These sensors are arranged side by side and are mounted in front of the eye. Both the sensors are wired with IC 567, this is a tone frequency generator cum decoder IC, means this IC can produce a tone frequency of up to 20 KHz, and the same IC also can decode the frequency. Since this IC can perform two different functions, the IR signal transmitting LED is connected at the output of tone signal generating part of IC, similarly the IR signal receiving LED is connected at the output of tone signal decoding part of IC. The tone signal generating part is configured as free running oscillator, with the help of a resistor and capacitor connected externally to this oscillator frequency can be adjusted. When the circuit is energized it starts producing a continuous chain of square pulses. The output of this oscillator is amplified and fed to IR LED. This LED radiates the signal in to air and depending up on the signal strength or radiating power, the range can be increased. The IR signal delivered from the IR LED transmitted in a line like a laser beam, this beam is invisible and harmless. When the transmitted laser beam interrupted by closing of the eye, this beam will be disturbed by the object and some of the signal will be reflected, this reflected signal will be received by the receiver infrared LED. The output of IR-Receiver is (proportional to reflected wave) found for matching (comparing) with that of transmitted wave, and then the output of the IC will becomes low automatically (If both are equal then output of this IC becomes low). The output of this tone decoder IC is fed to microcontroller.
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 IR sensor indicates the presence of an object which is within the range. A part of the transmitted energy is intercepted by the target and re-radiated in many directions. The radiation is given back towards the system that is collected by the receiving LED which causes to produce a high signal at Pin No.8 of LM567 IC. The output of the receiver is fed to the microcontroller.
A small push to ON switch is interfaced with microcontroller, for giving the input that the break is applied; this key has to be activated to apply the break. In addition two more such switches are used to demonstrate the vehicle speed movement that is shown by the operation of a DC motor. By pressing one button the motor will be rotated at high speed indicating the vehicle moving at over speed and the other button to indicate normal speed at which the motor will be rotating at lower speed.
WATER (WET ROAD) SENSING:
To find the wetness an electronic circuit is designed, which takes care of the monitoring of water (wet road) continuously. For this, two electrodes are used. One electrode is fed with +5V DC and the other electrode is used for indicating the sensitivity of the road to the micro controller. When the road is completely dry, the electrode will be in open circuit condition. Since water is a conductor of electricity, whenever the road becomes wet, conduction makes continuity between the conductors (electrodes) and a logic high signal will be received by the controller if water is detected. The output of sensing electrode is fed to microcontroller and according to the high/low signals from the electrode; the microcontroller senses the road condition wet or dry.