Department Publications

A wired fence based intrusion detection and alerting mechanism for boundaries separating wildlife habitats and human settlements was implemented, particularly as a solution to the Human-Elephant Conflict (HEC). The objective of the research reported in this paper is to propose and verify an alternative technique for this wired fence based alerting mechanism to overcome its limitations and to improve its effectiveness. This article presents a comprehensive study of alternative solutions with deliberate consideration of the practical constraints. Wi-Alert is a wireless sensor network based intrusion detection system proposed as the best alternative solution. This article reports the outcomes of the first two phases of ongoing developments of Wi-Alert. The first phase of experiments was conducted to investigate the multi-path effect reduction techniques at one site. In the next phase, experiments were conducted to verify …

The paper presents a wireless body area sensor network (BASN) for evaluating the effectiveness of fitness exercising. The goal of our work is to provide a mobile and an accurate way of quantifying the energy expenditure during a fitness exercise session. While energy expenditure estimates are available in modern exercise machines, no accurate method exists for outdoor exercising. The prototype system implemented includes an IEEE 802.15.4(Zigbee) based wireless body area sensor network which measures physiological and kinetic features related to the activity being monitored, and a mobile application for visualization of the estimated energy expenditure. The paper outlines the sensor hardware used, the body area network which collects the measurements from the sensor nodes, the algorithm for energy computation and experimental results. The system, once trained can be used with any form of outdoor …

Wireless Sensor Networks consist of inexpensive, low power sensor nodes deployed to monitor the environment and collect data. Gathering information in an energy efficient manner is a critical aspect to prolong the network lifetime. Clustering algorithms have an advantage of enhancing the network lifetime. Current clustering algorithms usually focus on global re-clustering and local re-clustering separately. This article, proposed a combination of those two re-clustering methods to reduce the energy consumption of the network. Furthermore, the proposed algorithm can apply to homogeneous as well as heterogeneous wireless sensor networks. In addition, the cluster head rotation happens, only when its energy drops below a dynamic threshold value computed by the algorithm. The simulation result shows that, the proposed algorithm prolong the network lifetime compared to existing algorithms.

We present a novel method where smart phone sensors are used to sense the prevailing traffic situation and to share extracted information among a community. Instead of using the power-hungry GPS receiver in the mobile device for detecting congestion through vehicular motion, we use the accelerometer along with a novel algorithm. We show that traffic congestion situations can be identified with 78% accuracy with our technique. Vehicular traffic has become a severe problem, particularly in the less developed countries. Therefore pre awareness of congestion situations is very important for an efficient lifestyle.

Wireless sensor networks (WSNs) composed of large numbers of sensor nodes to monitor the environment and collect data. Self-organization of sensor nodes has been widely investigated to enhance the quality of service provided by WSNs. This paper proposes a Severity based Clustering Algorithm for Emergency (SCAE) for WSNs. The residual energy of nodes and severity of the emergency environment are the key parameters of SCAE. The severity of the emergency situation is estimated by using Dempster-Shafer theory. SCAE minimizes the communication loss due to node failures in an emergency environment. This is achieved by delaying the cluster head failures in the network and allocating less priority to non-cluster heads to select their cluster head which might get dropped from the network quickly. Communication failures due to node failures have been minimized successfully by considering the severity …

Wireless sensor networks may contain hundreds or thousands number of sensor nodes, monitoring specified parameters in the environment. These sensor nodes have the ability to communicate with each other or directly to an external base station. Current clustering algorithms provide an effective way to prolong the network lifetime. However, gathering information and communicating with each other is crucial in an emergency situation. To address this problem, the paper proposes an emergency response unequal clustering algorithm for wireless sensor networks. The proposed algorithm has been able to utilize the energy usage of the network with the novel approach in unequal clustering. Furthermore, this addresses the node failures in an emergency situation. The simulation result shows that the proposed algorithm has optimized the energy usage and reduce the communication failure compared to other …

A wireless sensor network (WSN) specifically designed for detecting elephant intrusions into villages that border wildlife reserves and alerting threatened communities of the location of the same is described. Novel strategies for hardware, firmware and communication have been applied, exploiting the rareness of events to be detected and the low data rates and light traffic load involved, in order to balance power consumption, cost, easy installation and testing in rural areas. Attempts have been made to build in automatic preventive maintenance measures and maintainable by personnel without technical know-how. The paper presents the design of the system and the experimental evaluation of a prototype implementation.

In an emergency, combining Wireless Sensor Network's data with the knowledge gathered from various other information sources and navigation algorithms, could help safely guide people to a building exit while avoiding the risky areas. This article presents an emergency response and navigation support architecture for data gathering, knowledge manipulation, and navigational support in an emergency situation. At normal state, the system monitors the environment. When an emergency event detects, the system sends messages to first responders and immediately identifies the risky areas from safe areas to establishing escape paths. The main functionalities of the system include, gathering data from a wireless sensor network, which is deployed in a multi-story indoor environment, processing it with information available in a knowledge base, and sharing the decisions made, with first responders and people in …

This paper introduces techniques for designing and implementing remotely controllable outdoor robots with the ability to localize itself while traversing in hazardous environments. The robot platform designed is a semi-autonomous tiller modified as required by the application. Localization based on wireless sensor network which has been a research interest of is addressed here with the use of Zigbee protocol. A Kalman filter was applied for the initial gathering of training data. For the improvement of the accuracy of position estimation, a fuzzy inference system is introduced. An extended Kalman filter is applied at the end in order to fuse the encoder data with the filtered RSS data. Results prove that a metric accuracy varying from 2m to 10m is achievable depending on the location of the robot with respect to the sensor nodes.

Sustainable retrofit of community buildings is a timely and strategic approach to reduce the community buildings’ greenhouse gas emission contribution. The objective of the project entitled Sustainable renewal/retrofit of public buildings is to deliver reliable and strategic plans for sustainable renewal of community buildings. This paper reports the work carried out in the first phase of the post-evaluation stage of the Sustainable renewal/retrofit of public buildings project. The pilot trial version of the dual purpose sensor network is discussed here. The first version of ZigBee (IEEE 802.15) based wireless sensor network is developed to measure the Indoor Environment Quality of the building which is capable of performing post-retrofit validation for the project.

A satellite elephant collar is a device mounted on an elephant's neck to track its position and movements. This information is essential for conservation and management of this highly endangered species. Currently available units are proprietary designs by few manufacturers and no literature can be found about their internal operation. This lack of published information hampers the evolution and development of future collaring systems with increased features and functionalities for research, conservation and management. Critical issues for improvement include live time of the collar, which is related to power consumption and operational modes of the unites, and remote programmability allowing for changes in data acquisition during deployment. Most commercially available collars lack the ability to change data acquisition schedules remotely over the air, and therefore data acquisition is un-optimized, which is …

Lankan agricultural community. The objective of this paper is to identify the methods and implementations that can be applied to the agricultural sector of Sri Lanka. While composing the framework with identified implementations the cost, scientific and technological knowledge of the farmers were taken into consideration.

It is known that every working day millions of drivers are looking for a place to park and most of the urban traffic occur due to the drivers loitering in search of parking spaces. We wished to offer a simple solution to this problem by implementing a car park navigating system using ultrasonic sensors. RS-485 protocol, a mobile application and Bluetooth communication. The system indicates whether the car park is full or not and provide a simple navigation to the driver to the vacant spot.

We present the design and implementation of intrusion detection and alerting mechanism (eleAlert) for fences separating wildlife habitats and human settlements. Our objective is to improve the effectiveness of electric fences as a solution to the prevailing human-elephant conflict (HEC) in many parts of the world. eleAlert uses a network of sensors to detect and locate damages instantly and alert communities under threat via the mobile communications network.

We present an effective solution for both digital map generation and real time user tracking for teams operating in hazardous environments or unfamiliar territory. The system is based on the client server model, where the client is a GPS enabled mobile phone which is capable of capturing coordinates and serving dynamic maps to the user. The maps plot the team's navigational routes and enables real time tracking of each other. The server builds a GIS at the back end based on the data sent by the users, and also develops maps on demand. The system is implemented with simple hardware and uses the available GPRS network for data gathering. This enables the system to be used both in hazardous environments and by the general public.

Bluetooth is a high end wireless technology designed for short range communications with high means of integrity. The application of Bluetooth technology for remote monitoring and control is an evolving concept in automation. However, in these applications, the controller which is controlled via Bluetooth technology or the sensor which transmits the sensed values via Bluetooth technology is application-specific. On the other hand, more productivity can be achieved by making the module general purpose, such that it can be used for wide range of applications. In fact, the general purpose concept can be applied to a selected set of devices with standard data interfaces, by making the system general purpose to the developer rather than the end user. In this work, a general purpose controlling module is designed with the capability of controlling and sensing up to five devices simultaneously. The communication …

Testing of wireless sensor network protocols can be tedious for large networks when mobility is added. Mainly because these networks involve a large number of nodes scattered in an ad-hoc configuration. Although there are several publicly available static sensor network testbeds, testbeds where mobility is facilitated are very rare. One of the main objectives of this work is to provide a general hardware platform, which supports to implement different protocols for mobile sensor networks. The testbed is implemented with one base station node, one mule and five sensor nodes, where data mules move in a random manner through a community of fixed sensor nodes. As the mule comes within range of each sensor node, it collects the available data. After collecting data from all the sensor nodes, the mule returns to a central node, where it uploads all the data collected. The motes are connected to the central node …

Wireless sensor networks are an emerging area of interest among embedded and wireless research groups around the globe. It is envisioned that these low power computers will become the enabling technology in pervasive computing and bring about the next paradigm shift in computing. We present a new type of MAC protocol that is applicable to a special type of mobile wireless sensor network. In this network, mobile sensor nodes will sense the environment, and buffer the measured data for later retrieval. Once within range of the base station, the mobile mote will have a considerable amount of data to upload to the base station. Such a system could be used in different applications such as analyzing migration patterns of animals (ex. elephants) or offline monitoring of vehicle fleets. We present a MAC protocol that will maximize the throughput of the said network, and thereby ensure that the maximum amount of …

In this paper we are presenting a low cost, locally developed customized monitoring and controlling system for a water purification plant. This system can facilitate monitoring and controlling of the entire plant from a single location. Apart from the major functions of monitoring and controlling through a GUI, additional functionalities such as providing remote terminals to the management via a LAN, generating reports, keeping logs in historical database are provided through the system.

In a very high noise environment, conventional communication means suffer from significant degradation due to the external noise which can drown out the desired speech signal. Environments such as industrial complexes, manufacturing plants, battle fields are examples of extremely noisy environments. Mobility is also crucial requirement for communication in such environments frequently. The paper describes the design and implementation of a mobile wireless communication system which can operate in such an environment using effective noise cancellation techniques.

The optimum distribution of treated pipe-borne water is a critical requirement in countries which have a deficit production in comparison with the demand. However, in 3rd world countries, it is not feasible to design the entire water distribution network as a whole, to enable near-optimized delivery, due to economic constraints. The current practice in such countries is to operate the nodes of the water distribution network, such as pump houses and water towers, in isolation, based on ad hoc criteria. Improper co-ordination of these nodes leads to wastage and inefficiencies in the utilization of the scarce resource of treated water. Hence the challenge lies in improving the water distribution process via a network that has not been inherently designed to support optimum distribution. The proposed system presents a solution to this predicament by centrally monitoring and controlling the functionality of these points of …

The paper describes a system to automate the monitoring and recording of rainfall using cellular network infrastructure. The paper describes the hardware and the software components and the data communication aspects of the design, and their integration as a complete system. Ancient Sri Lanka had been proud for centuries, of a very successful agricultural economy. Today, even though Agriculture still plays a key role in the Sri Lankan Economy, the agricultural sector has failed to keep up with the adoption of advancing technology and has thus fallen behind many other developing nations. Weather information such as rainfall is critical for successful agricultural activities. Unfortunately present methods of monitoring such information utilize manual observation and recording of data which is highly error-prone. Automation of these monitoring methods can not only increase the reliability, but also improve the timely availability of data, and hence contribute significantly to the betterment of agriculture in day-to-day activities as well as to long-term planning. The system consists of rain gauges with wireless interfaces and a central station. The rainfall information is transferred via SMS (Short Message Service) messages to the central station via a GSM cellular network. The information is received in a database at the central station and can be accessed via the Internet, and the data analyzed.

Development of the hardware, firmware and control and monitoring software to interface the UNIROAD Traffic Signal Controller (TSC) to Advanced Traffic Control system (ATCS) is described. This system is capable of controlling and monitoring traffic signal controllers over a standard telephone link. It is specially developed at a low cost for third world countries such as Sri Lanka.

The current water meters in Sri Lanka are manually read monthly, consuming more expenditure on human resources by the water board of Sri Lanka. As a solution to that problem, automating and digitizing the water meter can be presented. In order to read out the digits on the water meter more conveniently and effectively in a resource constrained environment, a low-cost imaged based direct reading system is presented in this paper. This system can automatically identify the digits on the water meter through a template matching algorithm. After recognizing the digits of the water meter reading, the processed meter reading output is transferred to a central server via Narrow-Band Internet of Things (NB-IoT) technology. Recently, NB-IoT is one of the most promising Low Power Wide Area technology which has attracted much attention from both academia and industry.