• Title/Summary/Keyword: Military vessel

Search Result 52, Processing Time 0.028 seconds

A Study on the Controller Design of Unmanned Surface Vessel through Repetitive Learning Method (반복 학습을 통한 무인 선박의 제어기 설계에 관한 연구)

  • Kim, Mincheul
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.21 no.6
    • /
    • pp.850-856
    • /
    • 2018
  • In this paper, a controller based on repetitive learning control is designed to control an unmanned surface vessel with nonlinear characteristics and unknown parameters. First, we define the equations of motion and error system of the unmanned vessel, and then design an repetitive learning controller composed of system error and estimated unknown parameters based on repetitive learning control and adaptive control. The stability of the unmanned vessel model controlled by the designed controller is verified through the analysis of the Lyapunov stability. Simulation shows that the error converges asymptotically to zero with semi-global result, confirming that the unmanned vessel is moving toward a given ideal path, and verifies that the controller is also feasible.

A Comparative Study on Exciting Force for Luminaire of Naval Vessels According to Sailing Condition (함정 운항에 따른 조명등기구 가진력 비교 연구)

  • Park, Mi-You;Cho, Heung-Gi;Lee, Kowan-Woo;Yu, Young-Soo;Cho, Kyu-Lyong
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.15 no.4
    • /
    • pp.390-397
    • /
    • 2012
  • According to sailing condition, an exciting force for luminairie of naval vessels was measured and analyzed. A naval combat service support boat and P${\bigcirc}{\bigcirc}$(patrol killer guided missile) were selected as a target naval vessel. Due to their small size and fast speed, they received excessive vibration than other bigger naval vessels like destroyer. The vibration of luminairie was measured on their cruising and maximum speed. This could analyze exciting force for luminairie of naval vessels. Using this analyzed data, the validity of military standard for naval vessel was verified.

A Study on Thermal Insulator Effect for Structure Design of Internal Support on Cryogenic Vessel (단열재가 극저온 용기의 내부지지대 구조설계에 미치는 영향)

  • Kim, Doo-Ho;Ji, Hyun-Jin;Kim, Ki-Youl;Cho, Sung-Baek
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.14 no.3
    • /
    • pp.524-531
    • /
    • 2011
  • The cryogenic vessel, storing a liquified solutions as LOX and $LN_2$, consists of a external vessel, internal vessel, thermal insulator and internal support. The internal support should be satisfied with mechanical strength not only to support weight of internal tank but also to maintain uniform space between external and internal tank in spite of external mechanical shock. However, excessive structure design of internal supports is able to increase the amount of heat conduction and the rate of vaporization. The thermal insulator, filled with space between a external and internal vessel, reduces the rate of heat transfer and guarantees the standing time of cryogenic vessel. Especially powder type of insulator has low thermal conductivity and reduce the specification of structure design. In order to evaluate the effect of insulator on structure design, the experiment set-up simulated cryogenic vessel was tested in shock environment according to thermal insulator. As a result, the behavior of internal support under external shock was understood and the design criteria was able to be suggested.

Review of Shock Test Standards for Unifying Specification of Naval Equipments (함정탑재장비 규격통일화를 위한 충격시험기준 고찰)

  • Kim, Young-Ju;Kim, Joon-Won
    • Proceedings of the Korean Society of Marine Engineers Conference
    • /
    • 2005.11a
    • /
    • pp.214-215
    • /
    • 2005
  • Naval equipments are installed and used for naval vessel with different environmental conditions comparing to the commercial vessel, for example, high engine power per ship displacement size, severe vibration and shock due to high running speed and explosion from naval gun's bombardment and underwater weapons. Therefore, those equipments must be installed on shipboard with small spaces, high ambient temperature around engine room and which are required be fabricated with high resistances of vibration, shock and heat resources. But in case of commercial vessel, the performances of their recent equipments naval have been improved continuously due to the technology development of domestic shipbuilding and shipboard equipment industries, together with the related fundamental industries i.e, metal, steel and electronic industries, to an international level since 1970. With these results, it became possible to unify the specifications of shipboard equipments for the commercial and military vessels(Dual-Use). In this study, vibration and shock test standards for the commercial and military vessels will be compared and reviewed technically.

  • PDF

Path Tracking Controller Design for Surface Vessel Based on Sliding Mode Control Method with Switching Law (슬라이딩 모드 제어와 스위칭 기법에 기반한 수상함의 경로 추종 제어기 설계)

  • Lee, JunKu
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.20 no.1
    • /
    • pp.108-118
    • /
    • 2017
  • In this paper, the path tracking controller for a surface vessel based on the sliding mode control (SMC) with the switching law is proposed. In order to have no restriction on movement and improved tracking performance, the proposed control system is developed as follows: First, the kinematic and dynamic models in Cartesian coordinates are considered to solve the singularity problem at the origin. Second, the new multiple sliding surfaces are designed with the SMC and approach angle concept to solve the under-actuated property. Third, the switching control system is designed to improve tracking performance. To prove the stability of the proposed switching system under the arbitrary switching, the Lyapunov stability analysis method with the common Lyapunov function is used. Finally, the computer simulations are performed to demonstrate the performance, effectiveness and stability of the proposed tracking controller of a surface vessel.

A Calibration Technique and its Error Analysis for the Position of Seabed Sonar Target (해저고정 소나표적의 위치교정기법과 오차해석)

  • 이상국;이용곤
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.6 no.3
    • /
    • pp.15-21
    • /
    • 2003
  • This paper contains a precise calibration technique for the position of seabed acoustic target and theoretical error analysis of calibration results. The target is deployed on seabed as a standalone transponder. The purpose of target is performing accuracy test for active sonar as well as position calibration itself. For the position calibration, relative range between target and test vessel should be measured using target's transponder function. The relative range data combined with vessel position can be converted into a estimated position of target by the application of nonlinear LSE method. The error analysis of position calibration was divided into two stages. One is for relative range estimator and the other for target position estimator. Numerical simulations for position calibration showed good matching between results and developed CRLB.

Development of Aerospace Components Forming Technology using Superplasticity and Diffusion Bonding Characteristic (초소성 및 확산접합을 이용한 우주항공 부품 성형기술 개발)

  • Lee, Ho-Sung;Yoon, Jong-Hoon;Yi, Yeong-Moo
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.8 no.3 s.22
    • /
    • pp.51-55
    • /
    • 2005
  • In this paper, a near net shape technology using superplasticity and diffusion bonding characteristics was presented for application to various components of aircraft and missiles. Due to these special characteristics of some aerospace alloys, it is possible to produce complex components to shape very near final dimension with enhanced design freedom, reduced material usage, and overall saving of weight and cost. The high pressure vessel for a space launcher was fabricated with Ti-6Al-4V alloy by superplastic forming and diffusion bonding process and the failure characteristics are compared with conventionally fabricated vessel spin formed and TIG welded. The structural integrity of the superplastic forming and diffusion bonding process was successfully demonstrated.

A Study on Analysis Method of Underwater Electric Field Signature due to Ship's Corrosion and Corrosion Protection System (선체 부식 및 부식 방지장치에 의한 수중 전기장 신호 해석 방안 연구)

  • Chung, Hyun-Ju;Yang, Chang-Seob;Jeon, Jae-Jin
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.11 no.2
    • /
    • pp.43-52
    • /
    • 2008
  • The galvanic corrosion of a vessel, or systems fitted to minimize the ship's corrosion such as ICCP (Impressed Current Cathodic Protection) system and sacrificial anodes, can lead to significant electrical current flow in the sea. The presence of vessel's current sources associated with corrosion will give rise to detectable electric field surrounding the vessel and can put it at risk from mine threats. For this reason, it is necessary to design corrosion protection systems so that they don't only prevent a hull corrosion but also minimize the electric field signature. In this paper, we describe theoretical backgrounds of underwater electric field signature due to corrosion and corrosion protection system on naval vessels and analysis results of the electric field according to the ship's hull and it's propeller coating damage and ICCP anode displacement.

A Method of Applying Multitier Structures for Underwater Acoustic Multimedia Database System (멀티미디어 해상시험자료 데이터베이스 시스템을 위한 다계층 구조 적용기법 연구)

  • 정기현
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.4 no.2
    • /
    • pp.84-96
    • /
    • 2001
  • Test data for a naval vessel is massive, expensive and impossible to be retested in a underwater acoustic measurement on the same condition. So, it is very important. In this paper, I mention massive underwater acoustic multimedia database system that was developed to store a long time, manage systematically, supply raw data and analyze data to user in 2-tier structure. Also, I propose 3-tier structure to extend the current database system that can supply multimedia data.

  • PDF

Modeling and Simulation of Secondary Battery-Fuel Cell Propulsion System for Underwater Vessel to Estimate the Operation Time (수중함용 2차전지-연료전지 추진체계의 성능 예측을 위한 M&S 연구)

  • Ji, Hyunjin;Cho, Sungbaek;Bae, Joongmyeon
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.17 no.5
    • /
    • pp.694-702
    • /
    • 2014
  • One of the most important devices in an underwater vessel is a propulsion system. It should be a quiet and efficient system for stealthy operations in the large mission area. Hence lead-acid battery system has been used to supply the energy to electric motor. Recent technological developments and improvements, such as polymer electrolyte membrane(PEM) fuel cell and lithium polymer battery and have created the potential to improve overall power and propulsion performance. An underwater vessel always starts their mission with a limited energy and is not easy to refuel. Therefore design of energy elements, such as fuel cell and battery, and their load distribution are important to increase the maximum operating time of underwater vessel. In this paper, the lead-acid battery/PEM fuel cell and lithium polymer battery/PEM fuel cell were suggested as propulsion system and their performances were analyzed by modeling and simulation using Matlab/Simulink. Each model concentrated on representing the characteristics of energy element depending on demand current. As a result the effect of load distribution between battery and fuel cell was evaluated and the operation time of each propulsion system was able to be estimated exactly.