29-01-2013, 01:50 PM
A MOBILE GPRS SENSOR ARRAY FOR AIR POLLUTION MONITORING
A MOBILE GPRS.docx (Size: 1.5 MB / Downloads: 86)
INTRODUCTION
Many air pollution systems in urban and rural areas that utilize smart sensor networks and wireless systems were reported in recent literature. An environmental air pollution monitoring system that measures CO, NO2, and SO2 was reported. The system is based on a smart sensor micro converter equipped with a network capable application processor that downloads the pollutants level to a personal computer for further processing. A wearable and wireless sensor system for real-time monitoring of toxic environmental volatile organic compounds was developed in. An air pollution geo-sensor network consisting of 24 sensors and 10 routers was installed to monitor several air pollutants in. The system provides alarm message depending on the detected pollution types in the field. A high-resolution surveillance Web-camera was used to monitor air quality via the Internet. The associate editor coordinating the review of this paper and approving it for publication was Prof. Giorgio Sberveglieri. A wireless mesh network based on embedded microprocessors consisting of multiple sensors and multihop wireless communication is designed to cover a geographic area in. The system monitors and transmits parameters atmospheric environment to a command center. Another wireless sensor network system was developed to monitor indoor air quality in. The indoor environmental parameters were monitored and transferred to a client personal computer or personal digital assistant (PDA) using an RF transmitter. An outdoor air pollution monitoring system using ZigBee networks for ubiquitous-cities was reported in. The system integrates a wireless sensor board which employs dust, CO2, temperature, and humidity sensors. The system’s monitoring range is 270 m. An abstract model of a system based on long-range wireless communication was proposed in.Most of the above air pollution and quality monitoring systems are based on sensors that report the pollutants levels to a server via wired modem, router, or short-range wireless access points. In this paper, we propose a system that integrates a single-chip microcontroller, several air pollution sensors (CO, NO2, SO2), GPRS-Modem, and a general positioning systems (GPSs) module.
SYSTEM REQUIRMENT
A system can be characterized according to its functional and nonfunctional requirements. The primary functionality of a system while nonfunctional requirements describe attributes like reliability and security, etc. The system’s functional requirements are as follows.
• System must support accurate and continuous real-time data collection.
• System needs to store the data and provide access to a location map interface.
• System needs to support mobility.
• System must use minimum power.
• System must be accessible from the Internet 24/7.
• System must be compact.
• System must mostly use off-the-shelf devices, components, and standards.
• System must support two-way communication between the client and the server.
• System must be field-configurable.
• System should be easy to deploy.
HARDWARE ARCHITECTURE
To satisfy the system’s functional and nonfunctional requirements, two major building blocks are needed, namely: a Mobile Data-Acquisition Unit (Mobile-DAQ) and a fixed Internet-Enabled Pollution monitoring Server (Pollution-Server).The Mobile-DAQ unit is designed by integrating the following hardware modules shown in Fig. 1. As the figure shows, the Mobile-DAQ consists of a 16-bit single-chip microcontroller integrated with a sensor array using analog ports. The Mobile-DAQ is also connected to a GPS module and a GPRS-Modem using the RS-232 interface. Each of these components is described in the following.
16-Bit Single-Chip Microcontrollers:-
The microcontroller is a single-chip device that has rich built-in resources for digital input/output ports, 16 channels, 8/10 bits analog-to-digital converter, 8 input/output interrupt- driven timers, 12 Kbytes of RAM, 4 Kbytes of EEPROM, 256 Kbytes of FEEPROM, two RS-232 serial communication ports, 4 Control Area Networks ports,I2C and SPI communication ports [9]. These resources are more than enough for the proposed application.
Sensors Array:-
The sensor array consists of three air pollutions sensors including Carbon Monoxide (CO), Nitrogen Dioxide (NO2), and Sulfur Dioxide (SO2). As Table I shows, the resolution of these sensors is sufficient for pollution monitoring. Each of the above sensors has a linear current output in the range of 4 mA–20 mA. The 4 mA output corresponds to zero-level gas and the 20 Ma corresponds to the maximum gas level. A simple signal conditioning circuitwas designed to convert the 4 m A compatible with the voltage range of the built-in analog-to-digital converter in the 16-bit single chip microcontroller described earlier.
GPS Module:-
The GPS module provides the physical coordinate location of the mobile-DAQ, time and date in National Marine Electronics Association (NMEA) format .NEMA format includes the complete position, velocity, and time computed by a GPS receiver where the position The data packet from the GPS-Module includes an RMS Header followed by UTC time, data validity checksum, latitude, longitude, velocity, heading, date, magnetic variation and direction, mode, and checksum. The only information required for the proposed system is date, time, latitude and longitude. The GPS modem is interfaced with the microcontroller using the RS-232 communication standard.
GPRS-Modem:-
The general packet radio service (GPRS) is a packet-oriented mobile data service used in 2G and 3G cellular communication systems global system for mobile communications (GSM).The proposed system uses a GPRS-Modem as a communication device to transmit time, date, physical location and level of air pollutants. The modem used for the proposed system has an embedded communication protocol that supports Machine-to-Machine (M2M) intelligent wireless Transmission Control Protocol (TCP/IP) features such as Simple Mail Transfer (SMTP) E-mail, File Transfer Protocol (FTP), and Simple Messaging Service (SMS) services Protocol. The modem supports an RS-232 interface that allows Serial TCP/IP socket tunneling. The modem also has rugged aluminum enclosure making it suitable for the proposed system.
Pollution-Server:-
The Pollution-Server is an off-the-shelf standard personal computer with accessibility to the Internet. As Fig. 1 shows, the Pollution-Server connects to the GPRS-Modem via TCP/IP through the Internet and the public mobile network. The server requires a private IP address for the GPRS-Modem and communicates over a pre-configured port. The Pollution-Server connects to a database management system (MySQL) through a local area network (LAN). The Pollution-Server runs a WampServer stackthat provides the Apache Web Server in addition to the PHPServermunicipality,environmental protection agencies, travel agencies, insurance companies and tourist companies can connect to the Pollution-Server through the Internet and check the real-time air pollutants level using a normal browser on a standard PC or a mobile device. The Pollution-Server can be physically located at the Environmental Protection Agency (EPA) or similar government agencies.Environmental protection agencies, travel agencies, insurance companies and tourist companies can connect to the Pollution-Server through the Internet and check the real-time air pollutants level using a normal browser on a standard PC or a mobile device. The Pollution-Server can be physically located at the Environmental Protection Agency (EPA) or similar government agencies.
POLLUTION MONITORING SYSTEM
Sensor data monitoring system receives the measured data from sensor network and provide the useful information for users by understanding the condition of the remote place. The proposed monitoring system structure is based on the framework for context awareness. In order to controlthe geosensor network and to monitor air pollution, we use two system sensor network control system and air pollution monitoring system. The control system supports the operators which control sensor network such as sampling interval change and network status check. The operators are useful for keeping the good status of data transmission in geosensor network. The air pollution monitoring system supports sensor data abstraction and air pollution prevention models for understanding the pollution level and area. The models are used for providing alarm message and safety guideline for people in pollution area.