【正文】 《現(xiàn)代控制理論》 題 目 智能交通信號(hào)控制 學(xué)生姓名 學(xué) 號(hào) 學(xué) 院 專 業(yè) 指導(dǎo)教師 二Ｏ一 三 年 12 月 15 日 Intelligent Traffic Signal Control Using Wireless Sensor Networks and Vigneshwar. Santhanam Abstract:The growing vehicle population in all developing and developed countries calls for a major change in the existing traffic signaling systems. The most widely used automated system uses simple timer based operation which is inefficient for nonuniform traffic. Advanced automated systems in testing use image processing techniques or advanced munication systems in vehicles to municate with signals and ask for routing. This might not be implementable in developing countries as they prove to be plex and expensive. The concept proposed in this paper involves use of wireless sensor works to sense presence of traffic near junctions and hence route the traffic based on traffic density in the desired direction. This system does not require any system in vehicles so can be implemented in any traffic system easily. This system uses wireless sensor works technology to sense vehicles and a microcontroller based routing algorithm for traffic management. Keywords:Intelligent traffic signals, intelligent routing, smart signals, wireless sensor works. I. INTRODUCTION The traffic density is escalating at an alarming rate in developing countries which calls for the need of intelligent traffic signals to replace the conventional manual and timer based systems. Experimental systems in existence involve image processing based density identification for routing of traffic which might be inefficient in situations like fog, rain or dust. The other conceptual system which is based on interaction of vehicles with traffic signals and each other require hardware modification on each vehicle and cannot be practically implemented in countries like India which have almost 100 million vehicles on road [1]. The system proposed here involves localized traffic routing for each intersection based on wireless sensor works. The proposed system has a central controller at every junction which receives data from tiny wireless sensor nodes placed on the road. The sensor nodes have sensors that can detect the presence of vehicle and the transmitter wirelessly transmits the traffic density to the central controller. The controller makes use of the proposed algorithm to find ways to regulate traffic efficiently. II. THE NEED FOR AN ALTERNATE SYSTEM The most prevalent traffic signaling system in developing countries is the timer based system. This system involves a predefined time setting for each road at an intersection. While this might prove effective for light traffic, heavy traffic requires an adaptive system that will work based on the density of traffic on each road. The first system proposed for adaptive signaling was based on digital image processing techniques. This system works based on the captured visual input from the roads and processing them to find which road has dense traffic. This system fails during environmental interaction like rain or fog. Also this system in testing does not prove efficient. The advanced system in testing at Pittsburgh [2] involves signals municating with each other and also with the vehicles. The proposed system does not require a work between signals and vehicles and is a standalone system at each intersection. III. THE PROPOSED SYSTEM This paper presents the concept of intelligent traffic routing using wireless sensor works. The primary elements of this system are the sensor nodes or motes consisting of sensors and a transmitter. The sensors interact with the physical environment while the transmitter pages the sensor’ s data to the central controller. This system involves the 4 x 2 array of sensor nodes in each road. This signifies 4 levels of traffic and 2 lanes in each road. The sensors are ultrasonic or IR based optical sensors which transmits status based on presence of vehicle near it. The sensor nodes transmit at specified time intervals via ZigBee protocol to the central controller placed at every intersection. The controller receives the signal and putes which road and which lane has to be given green signal based on the density of traffic. The controller makes use of the discussed algorithm to perform the intelligent traffic routing. IV. COMPONENTS INVOLVED IN THE SYSTEM The proposed system involves wireless sensor works which are prised of three basic ponents: the sensor nodes or motes, power source and a central controller. The motes in turn are prised of Sensors and transceiver module. The sensors sense the vehicles at intersections and transceiver transmit the sensor’ s data to the central controller through a wireless medium. The Power source provides the power needed for the sensor nodes and is mostly regenerative. The central controller performs all the putations for the sensor works. The controller receives the input from all sensors and processes simultaneously to make the required decisions. Sensors are hardware devices that produce a measurable response to a change in a physical condition like temperature or pressure. Sensors measure physical data of the parameter to be monitored. The continual analog signal produced by the sensors is digitized by an analogtodigital converter and sent to controllers for f