• Title/Summary/Keyword: Characteristic design parameters

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A Study on the Design of Linear PID Controller (선형 PID 제어기 설계에 관한 연구)

  • Cho, Joon-Ho
    • Journal of Industrial Convergence
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    • v.16 no.2
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    • pp.33-39
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    • 2018
  • This paper describes the design method of the linear PID controller and proposed the design method in the future. The first PID design method is to ensure phase margin and gain margin. This method guarantees stability by designing in the frequency domain. The second method is an internal model control method. This method is to design the PID controller using the parameters of the internal model after identifying the internal model for the control model. Therefore, this method has a strong disturbance characteristic. Finally, a proposed Cascade and smith-Predictor controller. The combination of the cascade controller and the smith-predator of this method is a controller structure that has two advantages: robust control and optimal control. This method can obtain the performance evaluation index as the optimal controller design method. This PID controller design method becomes the basis of the nonlinear method and is being continuously studied.

Phase shitter design and implementation of DGS using ferroelectric materials (강유전체를 이용한 DGS 구조의 위상 변위기 설계 및 구현)

  • Kim, Young-Ju;Park, Jun-Seok;Kim, Young-Tae;Kim, Sun-Hyeong;Kim, Hyeong-Seok
    • Proceedings of the KIEE Conference
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    • 2004.07c
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    • pp.2014-2016
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    • 2004
  • In order to obtain a low-loss ferroelectric phase shifter, the reflection-type phase shifter with ferroelectric defected ground structure (DGS) resonators has been designed in this paper. The proposed phase shifter is consist of a 3-dB $90^{\circ}$ branch-line hybrid coupler and terminated reflective circuit with tunable ferroelectric DGS resonator. The ferroelectric DGS unit structure can provide high Q resonator characteristic at high frequencies. The design parameters of equivalent circuit for the tunable DGS resonator are derived by using simple circuit analysis method and three-dimensional full wave finite element method. The fabricated phase shifter has an insertion loss of better than 3.4dB at 13.5GHz.

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Design of Compact Microstrip Patch Antenna for Short Distance WLAN (근거리 WLAN을 위한 광대역 마이크로스트립 패치 안테나 설계)

  • Choi, Yong-Seok
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.13 no.1
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    • pp.67-74
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    • 2014
  • In this paper, we designed a multiband monopole antenna for next-generation WLAN system. In conventional WLAN system, UWB antennas were used together, and, because the radiation occurs in different parts depending on the antenna structure, it has the disadvantage of having an unstable impulse response characteristic due to dispersion characteristics. Although a UWB antenna that has suitable radiation pattern for WLAN band, it does not have good impedance matching and has severe echo. Therefore, in this paper, a monopole antenna was designed by using CPW power feed so that various impedances can be easily implemented when designing an antenna and more parameters can be derived that can be used for design for optimal performance.

Design of an Error Model for Performance Enhancement of MEMS IMU-Based GPS/INS Integrated Navigation Systems

  • Koo, Moonsuk;Oh, Sang Heon;Hwang, Dong-Hwan
    • Journal of Positioning, Navigation, and Timing
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    • v.1 no.1
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    • pp.51-57
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    • 2012
  • In this paper, design of an error model is presented in which the bias characteristic of the MEMS IMU is taken into consideration for performance enhancement of the MEMS IMU-based GPS/INS integrated navigation system. The drift bias of the MEMS IMU is modeled as a 1st-order Gauss-Markov (GM) process, and the autocorrelation function is obtained from the collected IMU data, and the correlation time is estimated from this. Prior to obtaining the autocorrelation function, the noise of IMU data is eliminated based on wavelet. As a result of simulation, it is represented that the parameters of error model can be estimated correctly only when a proper denoising is performed according to dynamic behavior of drift bias, and that the integrated navigation system based on error model, in which the drift bias is considered, provides more correct navigation performance compared to the integrated navigation system based on error model in which the drift bias is not considered.

A study of flow oscillations in a upright heated pipe (직립전열관에서의 유체진동에 관한 연구)

  • 박진길;진강규;오세준
    • Journal of Advanced Marine Engineering and Technology
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    • v.8 no.1
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    • pp.85-99
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    • 1984
  • The stability of the two-phase flow in a heated channel is of great importance in the design and operation of the boilers and light water nuclear reactors, because it can cause flow oscillations and lead to a violation of thermal limits with resultant overheating of the channels and cladding. This paper presents a systematic evaluation to the variation effects of the basic four (4) dimensionless parameters in a homogeneous equilibrium model. The flow stability is examined on the ground of static characteristic curves. The complicated transfer function of flow dynamics which gives consideration to the transport lag of density wave is derived, and the transient flow stability is analysed by applying the Nyquist stability criterion in control engineering. The analysis results summed up as follows 1. The coolant flow becomes stable in large friction number and specific flow, while it is unstabale in small friction number and flow. 2. Large phase-change number and Froude number destabilize the two-phase flow, but small numbers stabilize it. The effect to variation of phase-change number is more dominant compared with Froude number. 3. The dynamic analysis is required to hold the sufficient safety of heated channels since only static results does not keep it. The special attention could be payed in the design and operation of heat engines, because the unstaable region exists within the stable boundary at small and middle phase-change number and Froude number.

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Characteristic Dynamics Torque Vibration of Behavior in Wet Clutch Engagement for Dual Clutch Transmissions (듀얼클러치 변속기용 습식클러치 체결에 따른 토크 변화에 대한 동적거동)

  • Cho, Jaecheol;Kim, Woojung;Jang, Jaeduk;Jang, Siyoul
    • Transactions of the Korean Society of Automotive Engineers
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    • v.24 no.2
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    • pp.183-190
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    • 2016
  • Engine torque is transferred to the transmission where drag torque is minimized improving fuel efficiency. This is particularly true in a wet clutch pack. This study measures slip friction when the wet clutch pack in a DCT (Dual-Clutch Transmission) is disengaged, and the friction pads are slipping. Shudder engagement velocity, and applied forces can be measured under various working conditions through these torque transfer experiments. Test results demonstrate that the design parameters, and engagement conditions of wet clutch packs can be optimized to reduce shudder and frictional vibration during engagement in a dual clutch transmission.

Investigation into Characteristics of Bending Stiffness and Failure for ISB Panel (ISB 판넬의 굽힘강성 및 파손특성에 관한 연구)

  • Ahn Dong-Gyu;Lee Sang-Hoon;Kim Min-Su;Han Gil-Young;Jung Chang-Gyun;Yang Bong-Yol
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.9 s.174
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    • pp.162-172
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    • 2005
  • The objective of this research works is to investigate into characteristics of bending stiffness and failure for the ISB ultra-lightweight panel with internally structured material. The expanded metal with a crimped pyramid shape and woven metal are employed as an internally structured material. Through three-points bending test, the force-displacement curve and failure shape are obtained to examine the deformation pattern, characteristic data, such as maximum load, displacement at maximum load, etc, and failure pattern of the ISB panel. In addition, the influence of design parameters fur ISB panel on the specific stiffness, the specific stiffness per unit width, failure mode and failure map has been found. Finally, it has been shown that ISB containing expand metal with the crimped pyramidal shape is prefer to that containing woven metal from the view point of optimal design for ISB panel.

Numerical Analysis of Deformation Mode of Flexible Plate-Type Piezoelectric Module for Evaluating Characteristics of Electrical-Energy Generation (판형 압전 진동자의 굽힘변형 모드에 따른 전압발생 특성에 관한 해석적 연구)

  • Park, Jeong-Hyun;Park, Sang-Hu
    • Journal of the Korean Society for Precision Engineering
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    • v.32 no.8
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    • pp.735-741
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    • 2015
  • Piezoelectric materials are well-utilized for transforming mechanical vibrations into electrical energy that can be stored and used to power a diversity of devices. In this work, these materials have been studied to improve the efficiency of a piezoelectric system, whereby the shape and vibration mode of a piezoelectric module was changed. The basic shape of the piezoelectric module used in this work comprises a width of 10 mm, a length of 30 mm, and a thickness of 0.2 mm. The structural design of the piezoelectric module is optimized using a Taguchi method to increase the corresponding electrical-energy generation. The maximum terminal voltage was defined as a characteristic value to evaluate the optimal design parameters. Through this work, we propose an optimal structure with an eccentric and centric mass; furthermore, the voltage increase of approximately 26% was obtained by comparing a general plate-vibrating piezosystem with an optimal plate-vibrating piezosystem.

Characteristics Comparison of Axial and Radial Flux Permanent Magnet Generators for 1.5kW Class Wind Power Systems (1.5kW급 풍력발전용 축자속/반경자속 영구자석 발전기의 특성 비교)

  • Ko, Kyoung-Jin;Jang, Seok-Myeong;Koo, Min-Mo;Lee, Sung-Ho;Han, Sang-Chul;Park, Young-Tae
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.1075-1076
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    • 2011
  • This paper compares performance characteristics and mechanical design specifications of outer rotor radial flux type and double-sided axial flux type permanent magnet generator for 1.5-kW class small scale wind power applications to suggest most suitable type. In order to analyze electromagnetic performances of two different type generators, this paper performs generating performance and efficiency characteristic analysis from electrical parameters obtained by using nonlinear finite element analysis using commercial software, electromagnetic losses characteristics equations and d-q characteristics equation. Considering the derived electromagnetic performance, mechanical design specifications and manufacturing cost, the best suitable model for 1.5-kW class wind power system is determined, and its experiment was performed to validate the suggested analysis method.

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A Study on the Design of decision logic for n Tire Pressure Monitoring System (타이어 공기압 모니터링 시스템의 판단 로직 설계에 관한 연구)

  • Kim Byeong-Woo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.7 no.3
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    • pp.285-290
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    • 2006
  • In a Vehicle, Safety is the most important factor for drivers. It is well known that tire pressure lower than normal reduces the safety of the vehicle. In a consideration of active safety, tire pressure monitoring system is absolutely required. Tire pressure monitoring using in-tire pressure sensors with an RE data link have proven to be best approach to measuring tire pressure over the widest range of operating conditions. In this paper, we describe the parameters of TPMS, the characteristic of tire pressure and temperature compensation. These are the main factors to design the decision logic. We will show the guidelines for TPMS logic development considering environment variables and vehicle conditions.

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