Adaptive Traffic Monitoring and Controlling System (ATMC)

Sameer Mishra Vibhav Lohani

Department of Electronics and Communication Engineering College of Technology

G.B. Pant University of Agriculture & Technology Pantnagar-263145, Uttarakhand

INDIA sameer2mishra@gmail.com,vibhav87@gmail.com

Abstract ATMC is a cheap, automatic and practical traffic monitoring and controlling system which requires no human supervision at all. Driving License would be replaced by the smart card, which would work as e-key required for starting the vehicle. If a vehicle breaks the traffic signal, this system gets the information about the vehicle using RF communication and disconnects the starting circuit of vehicle from the battery. This is an adaptive system which senses the traffic and then adjusts the traffic light durations accordingly. 1. Introduction ATMC system provides a cheap, automatic and practical traffic monitoring system. This system provides the solution to two predominant problem of traffic at places were traffic light controls the traffic, first , it identifies the vehicles that break the signal and then forces them to stop or to report to the Traffic controller ,second adjusting Green and Red Traffic light duration to control the traffic. It is a fully Microcontroller controlled system. ATMC system senses the vehicle 25meters ahead of the signal using an IR beam .As the vehicle crosses this beam the output of IR receiver goes low momentarily and is detected by the microcontroller connected to it. Microcontroller in traffic unit keeps a count of vehicles crossing 25m line in each lane and thus monitors the amount of traffic in each lane. Using this information it changes the Green and Red light timing of each lane depending upon:

a) If any lane is empty or has very few vehicles, it gets lesser green light time. b) If any lane has comparatively higher amount of traffic, Green light ON time for it can be increased. This system again senses the vehicle at the signal crossing using IR beam. If a vehicle crosses the signal during RED light this system not only gets the information about the vehicle but also disconnects the starting circuits from the battery using RF (Radio frequency) communication technique so that the vehicle can not be started next time. 2. Components 2.1. PIC16F877A Microcontroller: We are using a PIC16F877A microcontroller from Microchip. This is a 40 pin device with 33 I/O pins. This uses CMOS Technology so it has Low-power consumption and high-speed of operation with 200 ns instruction cycle .Its features include In-Circuit Serial Programming (BOOTLOADING) via two pins. It is easy to program it with only 35 single-word instructions. PIC16F877A also has a Master Synchronous Serial Port (MSSP) module that is a serial interface, useful for communicating with other peripheral devices through Serial Peripheral Interface (SPI).This module is used for communicating with the smart card reader. 2.2. 433 KHz RF Receiver-Transmitter pair:

International Conference on Advanced Computer Control

978-0-7695-3516-6/08 $25.00 © 2008 IEEE

DOI 10.1109/ICACC.2009.125

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International Conference on Advanced Computer Control

978-0-7695-3516-6/08 $25.00 © 2008 IEEE

DOI 10.1109/ICACC.2009.125

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We are using ASK (Amplitude Shift Keying) based TX/RX pair operating at 433 MHz. They can be directly interfaced to a microcontroller or can be used with the help of encoder/decoder ICs. Also they are easily available and cheap. The encoder IC takes in parallel data at the Transmitter side, packages it into serial format and then transmits it with the help of a RF transmitter module. At the Receiver end, the decoder IC receives the signal via the RF receiver module, decodes the serial data and reproduces the original data in the parallel format. 2.3. IR LED (transmitter) and TSOP 1740 IR receiver module: IR led is used as the transmitter and TSOP 1740 is used as the IR receiver. Figure 1 shows the connection of IR transmitter and receiver. Figure 2 shows the connection for IR beam used in detection. 2.4. 4-channel encoder-decoder IC: We are using HT12A and HT12D from HOLTEK as encoder and decoder IC for IR communication. It uses Low power and high noise immunity CMOS technology .Both are 18 pin IC with 8 address pins and 4 data pins. HT12A provide 38kHz Carrier Output for long range infrared transmission. 2.5. 8-channel encoder and decoder IC: TRICoder–84 IC available at TRI Technosolutions is used as the both encoder and decoder. This is a 20 pin IC with 8 data pins and 4 address pins. Input applied to pin 12 decides the function of this IC, if it is HIGH then it works as a Decoder, if it is at LOW then it works as an Encoder. 2.6. SLE 4442 - SMART CARD: Smart Card contains the information about the Driver like Driving Number. Each user will have a unique Identification Number. SLE 4442 has a 256Byte EEPROM Memory. SLE 4442 provides a security code logic which controls the write/erase access to the memory. For this purpose the SLE 4442 contains a 4-byte security memory. Of this 4 byte one byte is called Error Counter EC and the other is 3 byte long Programmable Security Code (PSC) After three successive unsuccessful attempts the Error Counter blocks any subsequent attempt for PSC, and hence any

possibility to write and erase. Data can only be changed after entry of the correct 3-byte long programmable security code (security memory). Driving license No. is an integer and will be stored in Smart Card using the packed BCD representation. The digits will be stored in a fashion that the most significant digit is written first. For example, a 6 digit long No. 123456 will be stored using 3 bytes as 12H, 34H, and 56H. This information can be retrieved from the smart card using a smart card reader. 3. Circuit Description 3.1. Circuit description for the CONTROL UNIT: Control unit is established at road. Fig.3 shows the circuit diagram for the control unit. RA0-RA6, RB0-RB7, RC0-RC7, RD0-RD7, RE0-RE2 are the I/O pins of the Microcontroller. IR beam1 is 25m before the signal and is connected to RB6 of microcontroller. IR beam2 is at signal crossing and its output is connected to the RB0 pin of microcontroller. Data pins of HT12E are connected to the RA0-RA3 pins of microcontroller. Data pins of Tricoder Encoder and decoder is connected to the RB1-RB4 and RD0-RD7 pins respectively. RC6-RC7 pins of the microcontroller are for the ICSP 3.2. Circuit description for the VEHICLE UNIT: Figure 4 shows the circuit diagram of the vehicle unit. Data pins of HT12D are connected to the RA0-RA3 pins of microcontroller and address pins are connected to the VCC. RC6-RC7 pins of the microcontroller are for the ICSP. RA4 pin of microcontroller is connected to the relay which connects the battery and starter motor of the vehicle. RC3, RC4, RC5 pins of Microcontroller are used for SPI and are connected to the CLK_SPI, MISO, MOSI pins of the NCN-6804 smart card respectively. Connection of the TRICODER Encoder and Decoder data pins and address pin and Card reader interface with Smart card are shown in the Figure 6. 4. Working: 4.1. Traffic Monitoring: 1) To start the vehicle Smart card has to be inserted

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into the Card reader which is connected to microcontroller. Microcontroller stores the information about the driver in the smart card and connects the battery to the starter motor. 2) As the vehicle approaches the traffic lights it causes an interruption in IR beam2 and due to this vehicle is detected by control unit. 3)Now the microcontroller in control unit checks whether the traffic lights are Green or Red ,if the light is Red then Microcontroller sends 4 bit data to IR transmitter on the road to transmit it to the vehicle. IR receiver below the vehicle receives the signal and sends it to the microcontroller on the Vehicle .These 4 bits are the value of address bits of the Tricoder IC used for RF communication. These 4 bits help Microcontroller communicate with the concerned vehicle only using RF communication. 4) Now on receiving these 4 bits microcontroller breaks the circuit between starter motor and the vehicle battery and the vehicle can not be started from next time. 5)Then microcontroller on vehicle sends the Vehicle no. and Driver Identification No. to the control Unit Using RF transmission and control unit stores this data on receiving. After this the microcontroller clears the data in smart card and programs in it, so that both can not be used from next time. 6) To use the smart card and start the vehicle again both have to be reported to the Traffic control Office to reprogram them, were they could be penalized. 7) Or if they do not report to the Control office then information about them can be retrieved from the Microcontroller of the control unit to catch them. 4.2. Traffic Controlling: 1) As the vehicle goes past the IR beam, 25 meters before the signal it is detected and Microcontroller keeps a count of the vehicles crossing the IR beam. The vehicle is again detected on the signal crossing as it crosses the IR beam2 again, this time microcontroller subtracts one from the count. 2) If the count becomes zero during the GREEN light Microcontroller turns the Green light OFF for a fixed duration. 3)If the traffic in any lane is a lot compared to other lane, Green light duration for it can be increased .But the microcontroller keeps a count of the Vehicles in other lanes too, if their count increases rapidly and continuously during Red Lights, then Green light duration for each lane is made same again. 5. Details Of:

1. How is Microcontroller reprogrammed in the circuit? Microcontroller is reprogrammed by using a BOOTLOADER, which allows programming of the PIC16F877A serially via RC6 and RC7 pins, using a computer. A boot loader is a little program or function running on a PIC16F877A that takes incoming input and records the incoming data into the program area of the microcontroller’s memory. In other words, we send the PIC16F877A a serial signal of 1s and 0s and then it records these into the program memory. By using a boot loader, the end user can reprogram a PIC16F877A in the circuit only. All we need is a PIC16F877A that has been pre-programmed with Bootloader. It is such a program that to reprogram the Microcontroller using Bootloader a certain code is to be first sent to Microcontroller to start writing to its program memory. So everyone can not reprogram the Microcontroller. 2. How the RADIO FREQUENCY (RF) Communication takes place? Both the Vehicle and the control unit have the RF Receiver-Transmitter module on them Encoder and decoder ICs have their address and data pins connected to microcontroller and they provide and receive the data from the RF transmitter and Receiver respectively. So the microcontroller sets the address and data pins for transmission .Without address matching between Receiver and transmitter no communication can take place. As all the vehicles are using the RF module with same frequency, each vehicle has to be provided with a unique address to allow communication with it without any interference from others. Control unit transmits a 4-bit code to vehicle using an IR beam. These 4 bits act as the 4 address bits for RF encoder-decoder module (Tricoder). Now once the address is set communication between a particular vehicle and control unit is established. Microcontroller in the control unit stores the received information from the vehicle. 3. How the Microcontroller controls the Traffic Lights? Traffic lights are connected to the Microcontroller Pins of control unit which switches it ON and OFF. Microcontroller is programmed in such a way that it produces periodic interrupts every 5.5 seconds. On each interrupt it checks the status of light and then inverts the status. 4. How the starter circuit of vehicle works? Battery and starter motor are connected through a relay. Relay is connected to the Microcontroller pin. The duration for which the output of Microcontroller pin is high, the relay is energized and battery and

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starter motor are connected .When the output of pin is low the relay disconnects the circuit between the motor and the battery. 6. Further Enhancements: 1. If all the control units on road are connected with each other then this system can control the traffic in a more effective way as all the Traffic lights can be synchronized, and drivers can also be informed about the traffic ahead on their routes. 2. The same system can be used at Un-manned railway Crossing. To use this system at railway crossing in addition to vehicle, train would be also sensed some kilometers before the crossing by system. Then the information about the train approaching the crossing can be provided to the concerned vehicles. 3. This system could also be used for automatic parking systems, guiding vehicles to empty parking slots. 4. This system can be used to develop a security system that prevents vehicles thefts. 7. Advantages: 1) Low cost. 2) Efficient and reliable. 3) Compact. 4) Cost of operation is zero. 5) Totally Automatic. 6) Can be used anywhere.

8. Conclusion: The traffic monitoring and controlling system is so simple, cheap and effective that it can be used anywhere and also the cost of operation of this system is zero. The traffic monitoring techniques like CCTV and GPS are also available, but they require someone to monitor the data sent by them. This system is totally automatic and requires no human supervision. This system not only monitors the traffic but also takes the action in case someone breaks the traffic signal. 9. References: [1] Dr. RPS Gangwar, HOD, Department of Electronics and Communication Engineering, GBPUAT, Pantnagar, India [2] www.microchip.com [3] Tavladakis K., Kostalias K., Dollas A., Kalaitzakis K., Voulgaris N. C., 1997. “Development of a microcontroller-based, distributed, adaptive traffic control system”. Proc. 8th IFAC/IFIP/IFORS Symposium on transportation systems, Chania Crete. [4] www.siemens.com [5] http://triindia.co.in/shop/index.php?cPath=44

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