Faculty of Engineering, Electrical Engineering
http://dl.lib.uom.lk/handle/123/54
Theses / Dissertations submitted to Department of Electrical Engineering2024-03-28T12:43:57ZIncorporation of off - shore wind power as the next step of non - conventional renewable energy in Sri Lanka
http://dl.lib.uom.lk/handle/123/20908
Incorporation of off - shore wind power as the next step of non - conventional renewable energy in Sri Lanka
Prabhath NHM
With the current increasing trend for the non-conventional renewable energy (NCRE) in Sri Lanka, interest has been focused on retiring of thermal/coal power plants and getting the energy via renewable sources.
Since almost all the water sources have been used, the available options will be wind, solar, biomass etc.
From them, wind energy is more promising as it is having less intermittency and more efficiency compared to other sources. Offshore winds are more consistent than on shore winds as well as they are higher in speeds. Considering the Sri Lankan Sea territory massive energy can be harvested via offshore wind power with no or minimum affections to peoples’ lifestyle, existing inland natural beauty, relocation of people etc. compared to the onshore wind power. With being no/extremely little amount of effort required to relocate people and taking over lands, offshore wind power can be quickly implemented.
However, development of offshore wind farms around Sri Lanka should be carefully and seriously studied as it can also have negative impacts on some areas. It includes marine mammals & fish, coral reefs, migratory pathways of birds, fishing industry, tourism industry etc.
In this research a method is developed to locate suitable sites around a country for offshore wind power considering its technical, environmental, regulatory constraints. The method mentioned in this research is universal and validated on Sri Lanka. Initially the intended area of research (part of the Country’s Sea territory) was divided into equal areas. Then for each area the technical, environmental and regulatory constraints were analyzed using digitized maps. Creation of digitized maps using GIS software is also a part of this research.
Then weightage factors are developed for each constraints using a model developed in this research and a total value for each area is calculated. Then the intended area of study is linked with the values table for that particular study area using a GIS software to visualize the suitable sites.
2022-01-01T00:00:00ZSmart glove for recognition of sinhala sign language
http://dl.lib.uom.lk/handle/123/20979
Smart glove for recognition of sinhala sign language
Thalpawila V K O N
Speech and hearing-impaired people used sign language to communicate with each other. Sign languages are made of gestures. The language consists of different gestures instead of letters or words.
The purpose of this research work is to reduce the communication gap between normal people and hearing and speech impaired people. The research incorporates a system comprising of a glove-based mechanism, consisting of sensors to recognize the hand gestures for Sinhala sign language (SSL) alphabet.
The solution combines electronics, sensors, embedded systems, machine learning algorithms, and natural language processing. The research based on a data glove with flex sensors that measure finger bending and an Inertial Measurement Unit (IMU) to recognise palm-turning gestures of the alphabet. Further, sample data with eleven independent variables and hundred data samples per gesture was used for the purpose. In the proposed system, data is trained and classified using Random Forest machine learning algorithm. And natural language processing (NLP) is completed using a newly developed Application Programming Interface (API) to make Sinhala words.
The results show that the proposed algorithm has a better recognition effect on gestures, and is capable of making words and sentences. The accuracy of the model on the prepared dataset was founded as 99% for the target user with regard to random forest classification.
Complete training for all possible combination of letters and preparation of words is necessary to continue NLP. Also, the system can customise as an education platform for sign language learners. Further, the developed smart glove can use separately for any other hand gesture base applications, the developed ML base system can use or customize separately for feature extraction of any smart wearable item, and finally, the newly developed Sinhala API can use separately for any Sinhala sign language base NLP research work.
2022-01-01T00:00:00ZEnergy - based control in HAVC systems in commercial buildings to optimize the building energy performance
http://dl.lib.uom.lk/handle/123/21383
Energy - based control in HAVC systems in commercial buildings to optimize the building energy performance
Walgama SR
The severity of the emerging environmental problems and the criticality of a future
energy crisis with associated socio-economic quandaries are becoming strengthen along
with the inevitable growth of energy demand due to the ever-increasing population
and urbanization. Inspired by this, many state-of-the-art and efficient engineering
advancements under demand side management are being conceptualized, developed,
and examined via worldwide research for several years.
As one of the largest global energy consumers, buildings, and their Heating, Ventilating
and Air Conditioning (HVAC) systems acquire substantial attention regarding
optimal and efficient energy management. Nevertheless, longer computational time,
complicated implementation, deficient occupants’ thermal comfort and productivity,
and limited practicability and feasibility of most of the approaches that have been proposed,
have demotivated the industry applications even though they offer consequential
designing and operating advancements to the system. Therefore, the expected building
energy performance can be further extended by unraveling these encountered disputes
with novel energy saving strategies.
This research concentrates on energy optimal operation of HVAC systems by addressing
secondary chilled water pumping system, temperature setpoint management, cooling
water system, and temperature controllers in Air Handling Unit (AHU). Three different
innovative energy saving strategies to determine the optimal number of chilled water
pumps to be operated with their optimal speed, optimal zone temperature setpoint
schedule, and optimal cooling water flow rate with a setpoint of the chilled water supply
temperature have been proposed along with the consideration of system constraints,
safety, occupant thermal comfort, and satisfaction. In addition, a novel temperature
controller that can be utilized in AHU has been introduced and the performance in
comparison with available controllers has been studied. Simulation results obtained
via the case studies authenticate the effectiveness of the introduced approaches and
encourage the functioning of these strategies in real engineering systems due to the
inherent simplicity, robustness, and less computational complexity.
2022-01-01T00:00:00ZIncorporating biological signals for understanding user intentions for intelligent wheelchair
http://dl.lib.uom.lk/handle/123/21382
Incorporating biological signals for understanding user intentions for intelligent wheelchair
Abayasiri RAM
Over the years Intelligent wheelchairs which can gather information from the envi ronment to make decisions for itself have been developed to fulfil the needs of the wheelchair users. To improve the human robot interaction between the wheelchairs and the users, wheelchairs come with several types of controllers which are designed to meet the customer satisfaction. Use of biological/ electrophysiological signals for improved user satisfaction has an increasing demand all over the world. In order to incorporate user intentions for the navigation purposes and object manip ulation purposes of an intelligent wheelchair electrophysiological signals can be used. Due to the high signal to noise ratio and the fact that it does not require invasive surgical procedures to extract the electrophysiological signal, electromyography is used for above mentioned purposes. Since, electromyography is generated due to the motion intention ofthe user, it can accurately represent the intention of the user. Furthermore, the number of working muscles required to build a controller for above mentioned pur poses is high. Hence, it can be seen that most of the existing electromyography based controllers use muscles associated with hand movements as they can generate sev eral number of combinations of muscle activations depending on the hand movement/ grasping pattern. However, these are invalidated if the wheelchair user is suffering from physical conditions like trans-radial amputation where the upper limb is ampu tated between wrist and the elbow, trans-humeral amputation where the upper limb is amputated between shoulder and elbow and the partial/complete paralysis of the upper limb. This thesis proposes an Electromygraphy based controller for navigation and intelligent object manipulation of the wheelchair, which can be used even by the wheelchair users with trans-radial amputation, trans-humeral amputation and partial limb function. Any wheelchair user who has partial/complete function of biceps brachii of both of the arms, triceps brachii of the dominant arm and the right and left ster nocleidomastoid of the neck, can use the proposed electromyography based controller. Moreover, the controller is enhanced with vision sensor and a proximity sensor for the intelligent object manipulation task. By using the common user preferences and his previous experience in arranging objects on a wheelchair tray controller was designed to be user friendly. Experiments were carried out to monitor the adaptability and usability of the proposed Electromyography based controller among different users. Results confirmed that it can be used by any user after calibrating it for few trials. A human study was performed for different subjects to monitor whether patterns emerge in placing objects in different situations. After implementing a clustering algorithm, common locations and arrange ments for object placements were identified. Furthermore, experiments were performed after building the whole system inside the CoppeliaSim simulation environment, to monitor the capability of the proposed system in manipulating and arranging objects according to the user preferences in different situations. Simulation results proved that the proposed system can place the objects in accordance with the results of the human study.
2022-01-01T00:00:00Z