• Title/Summary/Keyword: Warships

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Basic Study on the Comparison of Performance of α-β-γ filter and Kalman Filter for use in a Tracking Module for ARPA system on Board High Dynamic Warships

  • Njonjo, Anne Wanjiru;Pan, Bao-Feng;Jeong, Tae-Gweon
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2016.05a
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    • pp.302-304
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    • 2016
  • The purpose of this paper is to draw comparison between the performance of ${\alpha}-{\beta}-{\gamma}$ filter and Kalman filter of a tracking module for ARPA system on board high dynamic warship. The comparison is based on the filters' capability to reduce residual error and maintain a stable transient response. The residual error is computed from the difference between the observed the predicted positions for the entire tracking period. The results indicate that the Kalman filter has a higher tracking accuracy compared to the optimal ${\alpha}-{\beta}-{\gamma}$ filter. However, both filters have a similar transient response.

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Basic Study of the Optimization of the Gain Parameters α, β and γ of a Tracking Module for ARPA system on Board High Dynamic Warships

  • Pan, Bao-Feng;Njonjo, Anne Wanjiru;Jeong, Tae-Gweon
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2016.05a
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    • pp.305-307
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    • 2016
  • The purpose of this paper is to determine the optimal values of the gain parameters used in the tracking module for a highly dynamic warship. The algorithm of the tracking module uses the ${\alpha}-{\beta}-{\gamma}$ filter to compute accurate estimates and update the state variables, that is, positions, velocity and acceleration. The filtering coefficients ${\alpha}$, ${\beta}$ and ${\gamma}$ are determined from set values of the damping parameter, ${\xi}$. Optimization is achieved by plotting a range of the damping parameter ${\xi}$ against the corresponding residual error and then selecting the best value of ${\xi}$ with the minimum residual error. Optimal values of the smoothing coefficients are subsequently computed from the selected damping parameter, ${\xi}$.

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Optimizing Concurrent Spare Parts Inventory Levels for Warships Under Dynamic Conditions

  • Moon, Seongmin;Lee, Jinho
    • Industrial Engineering and Management Systems
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    • v.16 no.1
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    • pp.52-63
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    • 2017
  • The inventory level of concurrent spare parts (CSP) has a significant impact on the availability of a weapon system. A failure rate function might be of particular importance in deciding the CSP inventory level. We developed a CSP optimization model which provides a compromise between purchase costs and shortage costs on the basis of the Weibull and the exponential failure rate functions, assuming that a failure occurs according to the (non-) homogeneous Poisson process. Computational experiments using the data obtained from the Korean Navy identified that, throughout the initial provisioning period, the optimization model using the exponential failure rate tended to overestimate the optimal CSP level, leading to higher purchase costs than the one using the Weibull failure rate. A Pareto optimality was conducted to find an optimal combination of these two failure rate functions as input parameters to the model, and this provides a practical solution for logistics managers.

Reduction of structure-borne noise from machineries including pumps (펌프류 장비의 고체음 저감에 관한 연구)

  • 김상렬;김현실;김재승;강현주;고성윤
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1998.04a
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    • pp.510-515
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    • 1998
  • Most of large structures such as ship, airplane, and so on have internal structure home noise sources. The operation of the machineries results in vibration and noise of the structure. Particularly, the vibration of the machineries is transmitted to the far place from the sources and emits noise into the water or outdoor as well as the inner space of the structure. In the case of warships this emission into the water induces noise to reduce the performance of its underwater acoustic equipment. Therefore the structure home noise levels of the installed machineries are strictly limited. This paper shows examples of structure home noise reduction from machineries including pumps.

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Prediction of Marine Propeller Noise Considering Scattering Effect (산란을 고려한 수중 프로펠러 소음해석)

  • Kim, Jong-Do;Hong, Suk-Yoon;Song, Jee-Hun
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.21 no.5
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    • pp.468-474
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    • 2011
  • Underwater radiated noises from marine vehicles are mostly due to the propulsion systems. Recently, the propeller noise problems are becoming crucial issues in terms of habitability of passenger ships. Especially in military area, propeller noise is directly related to the survivability of submarines and warships, and thus propeller noise analysis and reductions are very important. Generally, propeller noise can be classified into non-cavitating noise and cavitating noise which is dominant. In this paper the methodology of propeller noise analysis is announced and new approach to consider scattering effect is proposed. Unsteady blade surface pressure and sheet cavity volume analyzed with potential based panel method are used as noise source.

Impact Analysis for Sonar Domes Collided with Logs (수중 부유물에 의한 소나돔 충격해석)

  • Kang, Myung-Hwan
    • Journal of the Korea Institute of Military Science and Technology
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    • v.14 no.4
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    • pp.564-571
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    • 2011
  • During navigation of warships, sonar domes have been damaged by collision with floating objects like logs. In order to analyze the damage of a sonar dome from collisions with a log, The analytical method and the numerical analysis using ABAQUS are performed. Throughout the analytical method, the mechanism of collision between a sonar dome and log is analyzed. To design a sonar dome, the numerical analysis for A type sonar dome and the B type sonar dome have done considering fluid loading effect around the sonar domes with normal and maximum speeds of the ship, respectively. The numerical analysis results of the A type sonar dome and the B type sonar dome are compared and analyzed.

Prediction of marine propeller noise with scattering effect (Scattering 을 고려한 수중 프로펠러 소음해석)

  • Kim, Jong-Do;Hong, Suk-Yoon;Song, Jee-Hun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2011.04a
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    • pp.475-481
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    • 2011
  • Underwater radiated noises from marine vehicles are mostly due to the propulsion systems. Recently, the propeller noise problems are becoming crucial issues in terms of habitability of passenger ships. Especially in military area, propeller noise is directly related to the survivability of submarines and warships, and thus propeller noise analysis and reductions are very important. Generally, propeller noise can be classified into non-cavitating noise and cavitating noise which is dominant. In this paper the methodology of propeller noise analysis is announced and new approach to consider scattering effect is proposed. Unsteady blade surface pressure and sheet cavity volume analyzed with potential based panel method are used as noise source.

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A Comparative Study between Measurement and Prediction Results of a Naval Ship Infrared Signature in the Marine Environment (해상환경에서 함정 적외선 신호 측정 및 예측결과 비교 분석 연구)

  • Kim, Jung-Ho;Yoon, Yoon-Sik
    • Journal of the Society of Naval Architects of Korea
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    • v.48 no.4
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    • pp.336-341
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    • 2011
  • Ship infrared signature is the cause of detection and tracking by infrared sensor and anti-ship missile seeker. Recent warships have been applied the infrared stealth technology to reduce own ship infrared signature and tested to validate own ship infrared signature level. This study describes the two issues. Firstly, we describe the infrared measurement concept and infrared signature level establishment method that have been performed. Secondly, we compare and analyze the error components between the infrared measurement and simulation result.

A Study on Target Operational Availability Setting for Warship based on OMS/MP and Similar Warship RAM Analysis (함정 OMS/MP 및 유사체계 RAM분석 활용 기반 목표운용가용도 설정 연구)

  • Ha, Sungchul;Kim, Kyoungyong
    • Journal of the Korea Institute of Military Science and Technology
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    • v.15 no.5
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    • pp.651-659
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    • 2012
  • Target operational availability setting is the first step to setting up a goal which a weapon system development project have to achieve and doing RAM analysis during whole life of a weapon system. It is important as a key factor to doing RAM analysis in the early phase of weapon system development. This paper present a methodology to set a target operational availability for, especially, a warship when it develop. This methodology uses Operational Mode Summary/Mission Profile(OMS/MP) of the developing warship and RAM analysis results of similar warships to calculate wartime and peacetime target operational availability. It will be used in early phase of not only warship development but also army or aircraft weapon systems when these develop.

A Study for the new Technologies applying to the Next Generation Warship (차세대 군함에 응용될 새로운 기술에 관한 고찰)

  • Koo, Jong-Do
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2002.10a
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    • pp.61-67
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    • 2002
  • The joint warfighting environment, arranged by the net work-centrics, consists, with the situational awareness, the battlespace deconfliction, the joint force ID/location/allocation, and the ordnance on targets, considered by the concepts evolving In meet the future scenarios and threats. And then, the next generation warships have the operational requirements, such as the major offensive capability, the low operating cost, the ability to operate in net. centric forces, the revolutionary stealth, the in-stride mine avoidance, and the revolutionary manning. Therefore, the proposal discussed at this paper will be accepted in order to resolve only the portion of the afore-mentioned problems.

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