Faculty Publications
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Publications by NITK Faculty
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Item Dynamic Behaviour of Road Bridge Deck When a Truck Moves Along the Irregularities of the Road Profiles(Springer Science and Business Media Deutschland GmbH, 2022) Rahman, P.A.; Reddy, G.R.; Venkataramana, K.Bridge is the structure that is seen several dynamic loads unlike other structures. Ministry of Road Transport and Highways (MORTH) said that 10,876 people were killed due to potholes in the year 2015, which denotes the lack of proper maintenance of road pavements. When a vehicle moves along these surface irregularities, it not only causes uncomfortable to the passenger but also causes dynamic loads on the components like deck slab, bearings. Since the road surface irregularities like unevenness, potholes, etc., are unavoidable, we should understand the dynamic effect on the structure due to such undulations. IRC-6, standard to find the loads and load combinations on the road bridges, doesn’t talk about the dynamic load induced by surface irregularities with respect to the different classes of road profile as per ISO: 8608. On the other hand, IRC-6 only gives provisions of static analysis in the case of the vertical dynamic effect produced by moving vehicles. This study aims to generate road profiles having different degrees of unevenness as per ISO: 8608 and to propose a conservative method to find the vertical dynamic load on the bridge deck and its vertical response. A bridge deck is modeled as a Single Degree of Freedom system and the vertical dynamic responses of the bridge deck are found by Newmark’s Beta Linear Acceleration Method. It is found that the dynamic response, almost doubles when road profile quality changes from one class to the very next class. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.Item Computer controlled intrusion-detector and automatic firing-unit for border security(2010) Vittal, K.P.; Ajay, P.P.; Shenoy, S.B.; Srinivas Rao, C.H.S.This paper describes a novel computer-controlled intrusion-detector and automatic firing unit, which may be used for the surveillance of borders, either of a country, or of areas requiring high security, especially in regions of extreme climatic conditions, where it is difficult to deploy personnel. This system not only detects intrusion but also provides a video-coverage of the suspicious area, for remote vigilance, via a satellite based communication system. It is also provided with automatic firing mechanisms which can be used to automatically locate and fire at the target. Thus, several kilometres of the borders, which would have otherwise required several hundred personnel, can be effortlessly monitored with this system, with only a few personnel. Since, the actual firing occurs only after an authoritative personnel has doubly confirmed the presence of an intruder, chances of firing at innocent people are completely ruled out. As thermal cameras are used for imaging, this system is immune to changes in ambient conditions, and therefore, is equally suited for operation during the night. This paper also throws light on the prototype of this system, which has been successfully developed. © 2010 IEEE.Item Simulation of SVPWM based FOC of CSI fed induction motor drive(2012) Ronanki, D.; Rajesh, K.; Parthiban, P.The application of current source inverters (CSI)in induction motor (IM) drives offers a number of advantages, including voltage boosting capability, natural shoot-through short-circuit protection and generation of sinusoidal voltages. In this paper, an attempt to model the CSI fed IM drive is presented. The mathematical model takes into account of the inverter, and induction motor dynamics and is established in the stationary reference frame. For controlling the drive speed, a direct field-oriented control (FOC) is proposed. To counter the effects of torque pulsations at very low speeds and the rotor resistance variation, a slip angle compensation loop is included in the control law formulation. Analytical expressions for CSI fed IM with Direct FOC are derived and validated using MATLAB/SIMULINK. © 2012 IEEE.Item Harnessing hydroelectric power using Savonius rotor coupled with asynchronous generator connected to grid(IEEE Computer Society help@computer.org, 2013) Gao, S.; Pudur, R.The present investigation is aimed at exploring the feasibility of using vertical axis turbine which, otherwise, is ideally suited for wind energy conversion system (WECS), for hydropower generation. River water currents are potentially significant and reliable source of power generation and currently no significant work has been carried out to tap this source of energy. Electrical energy can be efficiently extracted from these free running rivers using vertical axis rotors that are similar in design and function to wind turbines but extract energy through hydrodynamic rather than aerodynamic mechanism. This paper presents possible generation of electrical power using Savonius rotor by coupling it with asynchronous generator, connected directly to grid. The model of each part such as Savonius rotor, asynchronous generator, and transmission line is proposed using MATLAB/Simulink. The model is tested for different velocities of river water and results are presented. © 2013 IEEE.Item Modeling and analysis of a SWCNT piezoresistive pressure sensor(2013) Bangera, A.E.; Kulkarni, S.The paper considers modeling and analysis of a circular diaphragm Single Walled Carbon Nanotube (SWCNT) piezoresistive pressure sensor using COMSOL Multiphysics. Initially, the analysis of piezoresistivity in SWCNT by the application of strain is done both by analytical and numerical approach using MATLAB and COMSOL respectively. It is observed that both results are comparable. Thus, the analysis of the structural deformation of the piezoresistive SWCNT placed above the diaphragm which results in the change of resistance in SWCNT, which is in direct accordance with the applied pressure is performed in COMSOL Multiphysis. The simulations show that the results obtained are linear and the sensitivity of the sensor is adequate. © 2013 IEEE.Item A small 4-wheeler EV propulsion system using DTC controlled induction motor(2013) Ronanki, D.; Hemasundar, A.; Parthiban, P.With the increasing need of electric vehicles (EV), necessary development is required to get reliable, efficient and economical drives for electric propulsion. Electric propulsion system using Induction Motor drive (IM) is becoming so popular because of its reliability, technological maturity and low cost. Field Orientation Control (FOC) is so popular in controlling the IM, but it has disadvantages like sensitive to parametric variation, external disturbance, load variation and also algorithm takes more time for execution, hence it requires a very fast microprocessor with high millions of instructions per second (MIPS) for implementation. In this paper, IM is controlled by using Direct Torque Control (DTC) technique because of its simple configuration and gives quick response. The mathematical model takes into account of the inverter, IM dynamics and vehicle aerodynamics. In this paper, the response of the IM with DTC for EV load for driving cycle consists of starting, acceleration, constant speed and deceleration modes are explained and validated using MATLAB/SIMULINK.Item Arguing formally about flight control laws(Institute of Electrical and Electronics Engineers Inc., 2015) Jeppu, N.Y.; Jeppu, Y.V.; Murthy, N.Flight control law software have errors. Some are found during the extensive testing and certification process and others pass through causing accidents. The testing of flight control software indicates that the code and the model match. But it is very difficult to ensure if the model was correct in the first place. Model checkers like Mathworks Simulink Design Verifier check the models against formally defined conditions and system behavior. The tool can come up with counterexamples that can fail an assertion or proof. A study is done on how easy or difficult it is to teach engineering students this formal process. The problem statement, the Simulink models and the outcome of the study in terms of advantages and disadvantages of using Simulink Design Verifier is highlighted in this preliminary study. © 2015 IEEE.Item Challenges in Developing Hardware-In-Loop Model of Cage Induction Motor with Eccentricity Fault(IEEE Computer Society help@computer.org, 2018) Ilamparithi, T.; Rangachar, B.; Rangineedi, T.; Nagendrappa, H.In this paper, an attempt is made to develop a MATLAB based Hardware-In-Loop compatible model of a three phase cage induction motor with a provision to accommodate eccentricity fault. The major benefits of the attempted work include compatibility with commercially available real-time simulators, facilitation of testing motor control units of electric vehicles when the motor is subjected to eccentricity fault, and ability to simulate in real-time varying severities of eccentricity fault. Modeling of the eccentricity fault is made by using the widely adopted modified winding function approach. Real-time simulation of the developed model is attempted by building a MATLAB model that utilizes pre-computed inductances for real-time execution. Finally, the major challenges encountered in this attempt are presented and discussed to pave way for further research. © 2018 IEEE.Item Analysis of Abrasive Wear Characteristics of Brass 60/40 Using MATLAB(Institute of Physics Publishing helen.craven@iop.org, 2018) Shadab Khan, M.; Shukla, A.M.; Ahed Khan, A.; Maurya, P.Abrasive wear behavior of Brass 60/40 was investigated using pin on disc wear testing machine. The abrasive wear test of brass was conducted by taking two variables viz. orientation and normal load. The normal load varies from 5N to 35N with different orientation angles (0°, 30°, 45°, 60°, and 90°), the speed of rotating abrasive disc kept constant at 1500 rpm. The experimental data was obtained from 5N to 20N only, by using pin on disc wear testing machine, however the data beyond 20N were validated with help of MATLAB. For proper validation of result for wear (mass loss), the exploratory data analysis (EDA) and regression analysis (RA) are used. These two analyses were conducted on MATLAB by using curve fitting tool and surface fitting tool. After the completion of experimental work, the results showed reduction in wear (mass loss) under constant loading condition with increase in orientation angle while increased in wear (mass loss) under constant orientation angle with increase in normal load. © Published under licence by IOP Publishing Ltd.Item Comparison of Sliding Mode Controllers on a DFIG-Wind Turbine Generator for Improving LVRT(Institute of Electrical and Electronics Engineers Inc., 2022) Hiremath, R.; Moger, T.There is a significant risk of grid failure for the grid-connected Doubly Fed Induction Generators (DFIG). There must be some thought put into the controller design for the DFIG's sensitivity to grid disruptions. We compare the Low Voltage Ride Through (LVRT) improvement using a Second Order Sliding Mode (SOSM) and First Order Sliding Mode (FOSM) controller under voltage sag conditions in this study. Sliding surface control convergence is aided by SOSM higher-order switching function augmentations. As a result of the SOSM's reduced chattering impact and enhanced system parameter settlement time, it has many benefits. By using MATLAB/SIMULINK, we are able to evaluate the SOSM's performance to that of other FOSM controllers that have been published. An analysis of DFIG-Wind Turbine (WT) system simulations found that SOSM controllers improved the system's LVRT capacity. © 2022 IEEE.