Adaptive Traffic Light Control System- A PLC Approach

Abstract

This paper presents the adaptive approach for traffic light control system by using programmable Logic ladder for the monitoring the PLC based traffic light system which helps in improving public transport service & traffic guidance system. System developed by setting the appropriate duration for traffic signals for react accordingly. In the rapid growing vigorously countries like India, accident occurred in huge numbers due to unmannered level of crossings are increasingly day by day. Main aim is to control the flow of vehicles through a lane for prevents accidents or road blockage. These systems are also used at points wherever a vehicles needs to be stopped for any purpose.  When the wheels of the vehicles move over the lane, sensor sends the signal to the PLC. There are three signals RED, GREEN, & YELLOW according to the lane density. Basic PLC functions such as timing, sequencing, controlling, and relaying were implemented based on logic ladder programming. Today’s scenario sensors are used to sense the presence of vehicles in a lane to calculate the density and send an interrupts signal to the control unit. Then PLC check the status of the sensor and certain logical operation is perform to decide which lane is to be serviced first on the basis of priority. Ladder diagram was developed for the implementation of that situation in PLC, which have check the priorities and after execution of program provide output to the traffic light poles for ON or OFF the RED, YELLOW, or GREEN lights and the ON/OFF time period dependent on the specific  priorities.