• 제목/요약/키워드: Design-Range Reduction Algorithm

검색결과 21건 처리시간 0.029초

사출 성형품의 두 품질특성 최적화를 위한 실용적 방법의 개발 (Development of a Practical Method to Optimize Two-Quality Characteristics in Injection Molded Parts)

  • 박종천;차재호
    • 한국기계가공학회지
    • /
    • 제14권6호
    • /
    • pp.90-97
    • /
    • 2015
  • Optimization of multi-quality characteristics in injection molded parts is very important, but it is sometimes difficult for part/mold designers. The objective of this study is to develop a practical design methodology for optimizing two-quality characteristics of injection molded parts. To attain this end, we developed a new design-range reduction algorithm based on Taguchi's orthogonal arrays for two characteristics. Then, the algorithm was integrated with commercial injection-molding simulation tools. A feature of the proposed methodology is that it allows field-designers unfamiliar with general optimization methods to be able to apply the methodology to their design problems with ease. Finally, we have applied the proposed design methodology to optimization of weldlines and deflections in an actual bezel model. The results show the usefulness of this methodology.

자동차 대시보드의 사출압력 최소화를 위한 게이트 위치와 공정조건의 강건설계 (Robust Design of Gate Locations and Process Parameters for Minimizing Injection Pressure of an Automotive Dashboard)

  • 김광호;박종천
    • 한국기계가공학회지
    • /
    • 제13권6호
    • /
    • pp.73-81
    • /
    • 2014
  • In this paper, multiple gate locations and process conditions under concern are automatically optimized by considering robustness to minimize the injection pressure required to mold an automotive dashboard. Computer simulation-based experiments using orthogonal arrays(OA) and a design-range reduction algorithm are consolidated into an iterative search scheme, which is then used as a tool for the optimization process. The robustness of a design is evaluated using an OA-based simulation of process fluctuations due to noise as well as the signal-to-noise ratio. The optimal design solution for the automotive dashboard shows that the robustness of the injection pressure is significantly improved when compared to the initial design. As a result, both the die clamping force and the pressure distribution in the part cavity are also much improved in terms of their robustness.

유전자 알고리즘을 이용한 판넬구조물의 구조음향 최적화에 관한 연구 (A Study on Acoustic Radiation Optimization of Vibrating Panel Using Genetic Algorithm)

  • 전진영
    • Journal of Advanced Marine Engineering and Technology
    • /
    • 제33권1호
    • /
    • pp.19-27
    • /
    • 2009
  • Globally, customer appreciation and demand for quieter products has driven noise control engineers to develop efficient and quieter products in a relatively short time. In the vehicles and ship industry, noise has become an important attribute because of the competitive market and increasing customer awareness. Noise reduction is often achieved through structural modifications by typical approaches. In the present paper, author describes a fundamental study on optimum design of curvature. Bezier curve. and rib attachment to reduce noise from simple panel using a genetic algorithm(GA). The acoustic optimization procedure employed p-FEM for structural analysis, the Rayleigh integral method for acoustic analysis and the GA for searching optimum design. In the optimization procedure. the objective function to be minimized is the average sound power radiated from an objective structure over a given frequency range $0{\sim}300$ Hz.

다중반사 구조를 갖는 복합구조물의 RCS 감소를 위한 광대역 다층 전파흡수체 설계 (Broad-band Multi-layered Radar Absorbing Material Design for Radar Cross Section Reduction of Complex Targets Consisting of Multiple Reflection Structures)

  • 김국현;조대승;김진형
    • 대한조선학회논문집
    • /
    • 제44권4호
    • /
    • pp.445-450
    • /
    • 2007
  • An optimum design process of the broad-band multi-layered radar absorbing material, using genetic algorithm, is established for the radar cross section reduction of a complex target, which consists of multiple reflection structures, such as surface warships. It follows the successive process of radar cross section analysis, scattering center analysis, radar absorbing material design, and reanalysis of radar cross section after applying the radar absorbing material. It is demonstrated that it is very effective even in the optimum design of the multi-layer radar absorbing material. This results from the fact that the three factors, i.e.. the incident angle range, broad-band frequencies, and maximum thickness can be simultaneously taken into account by adopting the genetic algorithm.

공조용 로터리 압축기 소음저감을 위한 어큐뮬레이터 최적설계 (Design Optimization of an Accumulator for Noise Reduction of Rotary Compressor)

  • 이의윤;김봉준;이정배;성춘모;이운섭;이종수
    • 대한기계학회논문집A
    • /
    • 제35권7호
    • /
    • pp.759-766
    • /
    • 2011
  • 최근 가정용 에어컨은 냉방효율뿐 아니라 소음에 대한 중요성이 지속적으로 높아지고 있다. 로터리 압축기는 에어컨의 소음 중 매우 높은 영향도를 가지고 있으며, 압축기의 소음을 줄이기 위해 머플러 및 공명기에 관한 많은 연구들이 진행되어 왔다. 압축기의 부품 중 어큐뮬레이터는 큰 용적으로 인해 공명에 의한 추가 소음을 에어컨에 전달하는 소음 전달경로가 되며, 어큐뮬레이터의 내부구조는 소음저감을 위해 중요한 설계요소가 되나 지금까지는 연구결과가 미비한 수준이었다. 본 논문에서는 어큐뮬레이터의 소음 저감을 위해 목표주파수 대역에서의 투과손실이 최대가 되는 설계최적화를 수행하였다. 높은 비선형성을 가진 문제의 최적화를 위해 실험계획법과 반경기저신경망기법을 이용한 근사 모델을 사용하였으며, 유전알고리즘을 사용한 최적화를 수행하였다.

전기자동차 급속충전기용 넓은 전압 범위를 갖는 30kW급 SiC MOSFET 기반 고속 스위칭 LLC 컨버터 설계 및 병렬 운전 (Design and Parallel Operation of 30 kW SiC MOSFET-Based High Frequency Switching LLC Converter With a Wide Voltage Range for EV Fast Charger)

  • 이기영;민성수;박수성;조영찬;이상택;김래영
    • 전력전자학회논문지
    • /
    • 제27권2호
    • /
    • pp.165-173
    • /
    • 2022
  • The electrification trend of mobility increases every year due to the development of power semiconductor and battery technology. Accordingly, the development and distribution of fast chargers for electric vehicles (EVs) are in demand. In this study, we propose a design and implementation method of an LLC converter for fast chargers. Two 15 kW LLC converters are configured in parallel to have 30 kW rated output power, and the control algorithm and driving sequence are designed accordingly and verified. In addition, the improved power conversion efficiency is confirmed through zero-voltage switching (ZVS) of the LLC converter and reduction of turn-off loss through snubber capacitors. The implemented 30 kW LLC converters show a wide output voltage range of 200-950 V. Experiments applying various load conditions verify the converter performance.

화재시 가시도 변화에 따른 대피속도 산정에 관한 연구 (A Study on the Evacuation Time by the Influence of Decreasing Visibility on Fire)

  • 이동호;박종승
    • 한국안전학회지
    • /
    • 제22권5호
    • /
    • pp.21-26
    • /
    • 2007
  • The computer program is developed to simulate the evacauation time for a building which is made geometrically complex. The program is intended for use both as a search and a design tool to analyze the evacuation safety through a wide range of structure environments. The computer program has a function of importing FDS's result to each individual resident in the building. These attributes include a walking speed reduction by producing visibility reduction for each person on the fire. $A^*$ pathfinding algorithm is adopted to calculate the simulation of escape movement, overtaking, route deviation, and adjustments to individual speeds due to the proximity of crowd members. Finally, a case study for a theater is presented to compared the calculated evacuation time with SIMULEX in detail. This program contribute to a computer program that evaluates the evacuation time of individual occupants as they walk towards, and through the exits especially for building, underground spaces like a subway or tunnel.

전동식 직접 구동형 능동 엔진 마운트의 설계 (Design of Active Control Engine Mount Using Direct Drive Electrodynamic Actuator)

  • 박현기;이보하;이종원
    • 한국소음진동공학회:학술대회논문집
    • /
    • 한국소음진동공학회 2007년도 춘계학술대회논문집
    • /
    • pp.1106-1111
    • /
    • 2007
  • This paper is focused on design of a new active control engine mount (ACM), which is compact in size and cost effective. The ACM, consisting of an electrodynamic actuator as the active element, flat springs and a sliding ball joint, is different in structure from the previous ACM designs based on the conventional hydraulic engine mount. Dynamic characteristics of the proposed ACM are extensively investigated before a prototype ACM, which meets the design specifications, is built in the laboratory. For cost effectiveness, a feed-forward control algorithm without a feedback sensor is used for reduction of the transmitted force through the ACM from the engine. The prototype ACM is then harmonic-tested with a rubber testing machine for verification of its control performance as well as adequacy of modeling. Experimental results show that the proposed ACM is capable of reducing the transmitted force by 20 dB up to the frequency range of 60 Hz.

  • PDF

Optimization of multiple tuned mass dampers for large-span roof structures subjected to wind loads

  • Zhou, Xuanyi;Lin, Yongjian;Gu, Ming
    • Wind and Structures
    • /
    • 제20권3호
    • /
    • pp.363-388
    • /
    • 2015
  • For controlling the vibration of specific building structure with large span, a practical method for the design of MTMD was developed according to the characteristics of structures subjected to wind loads. Based on the model of analyzing wind-induced response of large-span structure with MTMD, the optimization method of multiple tuned mass dampers for large-span roof structures subjected to wind loads was established, in which the applicable requirements for strength and fatigue life of TMD spring were considered. According to the method, the controlled modes and placements of TMDs in MTMD were determined through the quantitative analysis on modal contribution to the wind-induced dynamic response of structure. To explore the characteristics of MTMD, the parametric analysis on the effects of mass ratio, damping ratio, central tuning frequency ratio and frequency range of MTMD, was performed in the study. Then the parameters of MTMD were optimized through genetic algorithm and the optimized MTMD showed good dynamic characteristics. The robustness of the optimized MTMD was also investigated.

Design of the High Frequency Resonant Inverter for Corona Surface Processes

  • Choi, Chul-Yong;Lee, Dae-Sik
    • 한국정보기술응용학회:학술대회논문집
    • /
    • 한국정보기술응용학회 2005년도 6th 2005 International Conference on Computers, Communications and System
    • /
    • pp.119-122
    • /
    • 2005
  • A algorithm for control and performance of a pulse-density-modulated (PDM) series-resonant voltage source inverter developed for corona-dischange precesses is presented. The PDM inverter produces either a square-wave ac-voltage state or a zero-voltage state at its ac terminals to control the average output voltage under constant dc voltage and operating frequency. Moreover it can achieve zero-current-switching (ZCS) and zero-voltage-switching (ZVS) in all the operating condition for a reduction of switching lost. Even though the corona discharge load with a strong nonlinear characteristics, new high frequency resonant inverter is shown the wide range power control from 5% to 100%.

  • PDF