Defence Science Journal
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Comparison of Filtering Techniques for Transfer Alignment of Air Launched Tactical Guided Weapons
Full text linkThe transfer alignment technique is very useful for the accurate initialization and calibration of gyroscopes and accelerometers of INS for air-launched tactical guided weapon systems. In the present war scenario, the initialization of INS should be accurate and rapid to launch the tactical weapon against air or land targets within the shortest available time. A lot of development has been carried out by researchers for INS transfer alignment in the field of state estimation. The study and method presented in the research are relevant to aerial launch vehicles. However, to meet present guidance requirements within less time for initializing weapons, more appropriate transfer alignment algorithms are needed. This paper discusses the relative performance of Kalman Filter (KF), Extended KF, and Unscented KF for aligning the weapon INS using the data from Master INS. New developments, limitations, applicability, and design methods for the Kalman filters, became a key component in the transfer alignment of air-launched tactical missiles. These methodologies are extensively utilized in Navigation and Control systems; therefore, this research work will be an informative and perfect guide to existing and potential readers
A Novel & Efficient LR LSTM AIS Route Data Prediction for Longer Range
No full textThe growth of technology has enabled different industries to generate an excessive amount of data- one such industry being the maritime sector. Sophisticated sensory systems installed on various vessels generate information at a very large scale which can further be used in optimizing operational efficiency, improving safety standards, and aiding in the decision-making process. Researchers have henceforth identified statistical learning methods and machine learning techniques as potent tools for excavating useful insights from this copious amount of data available. This research evaluates how these algorithms work by focusing exclusively on the analysis of sensory data collected from vessels within the maritime domain. A comparison study has been conducted between statistical learning methods (which includes regression analysis, and time series analysis) vis-a-vis machine learning approaches. The major objective of this study was to determine the most effective method for detecting anomalies while simplifying marine operations and optimizing vessel behavior. The scope of the conducted analysis is restricted to the prediction of the next trajectory points. Accurate prediction of vessel positions plays a crucial role in maritime operations, enabling efficient route planning, collision avoidance, and maritime traffic management. In this article, the authors propose a combination model that combines the benefits of Linear Regression (LR) and Long Short-Term Memory (LSTM) techniques to anticipate vessel positions based on Automatic Identification System (AIS) data. The proposed model takes advantage of the interpretability of LR and the temporal dependencies collected by LSTM to capture temporal dependencies, which improve prediction accuracy and reveal the underlying links between vessel features and future positions
Conceptual Design Process of a Missile Model and Production Using Additive Manufacturing Method
Full text linkThis study focuses on air-to-ground missile systems, which are widely used in Turkey and around the world and are becoming increasingly important. The development of missile systems takes into account various requirements defined by the end user. It is important to identify a system and its subcomponents that fully meet the requirements. This study analyzes an air-to-ground missile system and its main subcomponents identified through the conceptual design method based on the systematic design approach proposed by Pahl and Beitz. The aim is to determine the feasibility of obtaining an optimal solution that meets the requirements set by the conceptual design method. The missile design’s optimal solution was modeled using SolidWorks software. A three-dimensional (3D) printer with FDM production technology was used to produce a prototype of the computer-modeled design. ABS and ABS-plastic blend filaments were preferred due to their material properties in the FDM production process. During the printing stage, the filament and output settings of the model were determined using the 3D printer’s interface program. The filaments were then extruded through a nozzle, following the cross-sectional geometry of the part. The resulting model was printed in pieces and assembled with a tolerance of 0.1mm. This process resulted in a 3D model of the missile, which was created to represent the system structure in different colours. The study demonstrates that the conceptual design method can be used to develop innovative and meaningful missile models
Static Weapon Target Assignment Based on Battle Probabilities and Time Discounted Reward
Full text linkTarget-based weapon-target assignment (WTA) aims to minimize the total value of enemies. It means that maximizing the total reduced value of the enemies is the objective of the target-based WTA. The reward of an assignment is typically set as the reduction in the enemy’s value when an ally and an enemy have combat, and the value is calculated by multiplying the current value of the enemy by the probability of the enemy’s survival after the combat. However, allies may be assigned to enemies who are far away if the reward is calculated similarly. Additionally, a method of calculating battle probability that reflects the characteristics and deployment of enemies and allies is needed in order to apply it in the defense industry. In this paper, we propose a target-based static weapon-target assignment to solve these problems. First, we propose a method to calculate battle probabilities for one-to-one, one-to-many, many-to-one, and many-to-many combat. The probabilities are composed of 4 cases; ally-survival-enemy-survival, ally-survival-enemy-destroyed, ally-destroyed-enemy-survival, and ally-destroyed-enemy-destroyed. Then a time-discounted reward for assignment based on the battle probabilities is calculated to consider the time it takes to have combat. Finally, the tank combat simulation results are discussed. The performance of the proposed WTA algorithm is highlighted through an analysis of assignment results and a comparison of outcomes based on the application of time-discounted rewards
Scramjet Intake Aerodynamic Studies Using Sharp Interface Immersed Boundary Method
Full text linkIn this present article, the use of a throttling device in the form of movable flap to study scramjet inlet unstart has been investigated numerically. The flap has been employed as an effort to simulate the rise in combustor pressure of the scramjet. Computational analysis for freestream Mach number and freestream pressure of and respectively, have been performed by a two-dimensional compressible CFD in-house Finite volume solver for perfect gas. Convective fluxes have been evaluated using AUSM scheme.Inviscidflow has been assumed for all the simulations. Particular point of interest in these simulations is the application of Immersed Boundary Method along the wall boundaries,enabling the use of structured grid for complex geometries. The results demarcate the starting condition of the inlet based on the flap throttling values. Comparative results in the form of Mach number and pressure contours are presented for different flap positions. The use of Immersed Boundary Method has been successfully displayed bysimulating a movable flap
Mitigating GHG Emissions from Military Supply Chain by Use of Aerial Cable Way
Full text linkThe transportation sector being one of the significant contributors to greenhouse gas (GHG) emission, there is growing concerns about environmental sustainability, and reducing GHG emissions which has prompted re-evaluation of transportation systems. The 1.5 million strong Indian defence forces have huge transport fleet and this study delves into the potential of Aerial Cableway (ACW) as a promising alternative mode of transport that can significantly reduce emissions of military supply chain in mountainous terrain. The study takes a case of Himalayan terrain to investigate how ACWs offer a low-impact, energy-efficient, and environmentally friendly solution compared to conventional ground-based transportation. It takes a case of Pharkian Pass in North Kashmir where defence forces has presence and this pass is often exposed to frequent landslides, snowfall and avalanches. Every year, on an average, approximately 12,000 trucks cross Pharkian pass in a year for purpose of logistics and sustenance. Without touching sensitive issues and by using a multi-criteria-based cost-benefit analysis, the study establishes that even if 75 % of road transport trips are shifted to ACWs, the reduction of GHG emissions is by 57.7 % in addition to significant benefits of the social cost of carbon, environmental costs, economic savings and ensuring strategic advantage like all-weather connectivity
Elastic Damage Healing Model Coupling Secondary Damage Variable for Self Healing Materials
Full text linkA one-dimensional constitutive model, based on the principles of continuum damage mechanics, is developed for capturing healing in certain materials during unloading and rest periods. A secondary damage variable is defined to address the drawback of existing models for damage and healing in capturing the complete material failure. An energy-based damage evolution function is adopted for primary and secondary damage variables, and phenomenological healing evolution is defined. The proposed implicit elastic damage-healing model is implemented by the return-mapping technique, and the model response is demonstrated for different loading histories
Analytic Model of Capture Probability for Salvo of Two Electromagnetic Launched Anti Torpedo Torpedoes
Full text linkTo pre-estimate the capture probability of electromagnetic coil salvo two anti-torpedo torpedoes (ATTs), an analytic model is proposed. Based on the analysis of the influencing factors, including the target position dispersion of the incoming torpedo, the entry point’s dispersion of the electromagnetic launched ATT, the underwater tracking speed and heading error of the ATT, and the differences between the salvo and single launch mode, a single integral analytic model of the capture probability is established. The course errors of the ATTs are comprehensively calculated utilizing search model, and the search boundaries of the two ATTs are calculated using the geometric method, taking the optimal searching course of the virtual single launch ATT as the desired searching course of the parallel salvo of the two ATTs. The calculation results of the proposed analytic model are consistent with the statistical results of the Monte Carlo approach through simulation comparison and analysis. The proposed analytic model’s consequences for decision-making and effect assessment are discussed
A Comprehensive Review of Dimensionality Reduction Techniques for Real time Network Intrusion Detection with Applications in Cybersecurity
Full text linkThis paper reviews popular signature and anomaly-based intrusion detection systems (IDS). Dimensionality reduction techniques (DRT) are used to increase the efficiency of such systems for real-time operation. Autoencoder-based IDS is rapidly gaining in popularity, primarily due to its inherent ability to denoise data and reduce dimensionality. In addition to the efficiency, we also look at the classification techniques used by various authors, and the overall impact of a model in terms of performance metrics. This article is written for novices in cybersecurityto get a jumpstart on the latest IDS algorithms. The purpose is to give useful insights into the broad and progressive view of various techniques in wide use, expose high-impact future research areas and to summarize classic IDS methods and feature selection techniques