• Title/Summary/Keyword: Acceleration mode

Search Result 532, Processing Time 0.03 seconds

Impact Angle Control for Non-maneuvering Target with Look Angle Measurements and Line of Sight (지향각, 시선각 정보를 이용한 이동표적의 충돌각 제어)

  • Park, Jang-Seong;Lee, Dong-Hee;Park, Sang-Hyuk;Kim, Yoon-Hwan
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.47 no.7
    • /
    • pp.508-516
    • /
    • 2019
  • In this paper, we propose a guidance law to control Impact Angle in consideration of look angle limit of the missile with strapdown seeker on the non-maneuvering target. The proposed law is based on sliding mode algorithm and generates acceleration commands using look angle and line of sight information provided by the strapdown seeker and navigation system. And, target velocity and target path angle are provided by like TADS (Target Acquisition and Designation System) at launch time. We can confirm that the target interception and impact angle control are possible through the convergence of the proposed sliding surface. In addition, it is possible to confirm that the sign of derivative result of the look angle at the maximum and minimum look angle is opposite to the sign of the look angle, so the look angle limit is not exceeded.

Design and Implementation of Remote Monitoring System for Underground Low Voltage Handhole Using Zigbee Communication (지그비 통신을 이용한 지중저압접속함 원격 모니터링 시스템 설계 및 구현)

  • Weon, La-Kyoung
    • The Journal of The Korea Institute of Intelligent Transport Systems
    • /
    • v.18 no.3
    • /
    • pp.58-67
    • /
    • 2019
  • The low-voltage connection box used as a low-voltage transmission line of KEPCO is intended to branch or connect to an underground line. In comparison with the utility considering the aesthetics of the distance, and safety measures are needed. In this paper, temperature and humidity, $CO_2$, water level, acceleration, and vibration sensor are installed inside the underground low voltage handhole, and the sensor data is transmitted to the ground using the Zigbee module. Antenna (Bolted Antenna) for communication with the ground was proposed and the data reception through it was confirmed. In the LF mode and the HEX mode, the transmitted data was confirmed to be a perfect reception success rate. In the case of the bolted antenna, the difference between the ground state and the underwater state was observed as a result of the experiment in the environmental environment. However, It was judged that reception sensitivity was sufficient for communication. The received data could be confirmed through PC based GUI.

FRF Analysis of a Vehicle Passing the Bump Barrier (둔턱 진행 차량의 주파수응답 분석)

  • Kim, Jong-Do;Yoon, Moon-Chul
    • Journal of Convergence for Information Technology
    • /
    • v.12 no.3
    • /
    • pp.151-157
    • /
    • 2022
  • The purpose of this study was to investigate the frequency characteristics of forced vibration considering the vehicle progress. And the vibration characteristics in frequency domain that occur, when vehicle passes the bump, were analyzed. The responses such as displacement, velocity and acceleration were obtained through numerical analysis, and FFT processing was performed to analyze the frequency response function(FRF) characteristics. In particular, the location of vehicle eigenmodes and external excitation modes was clearly shown and analyzed. In the forced vibration model by external force, the behavior of the eigenmode in power spectrum and real and imaginary parts were also analyzed. The mode characteristics were also analyzed in each FRF. It was approximated by assuming total excitation force by considering the exciting frequency using impulse and sine wave forces, which can give the amplitude and frequencies. The response characteristics of forced oscillations having different mass, damping and stiffness have been systematically discussed.

Binary Compound Formation upon Copper Dissolution: STM and SXPS Results

  • Hai, N.T.M.;Huemann, S.;Hunger, R.;Jaegermann, W.;Broekmann, P.;Wandelt, K.
    • Corrosion Science and Technology
    • /
    • v.6 no.4
    • /
    • pp.198-205
    • /
    • 2007
  • The initial stages of electrochemical oxidative CuI film formation on Cu(111), as studied by means of Cyclic Voltammetry (CV), in-situ Scanning Tunneling Microscopy (STM) and ex-situ Synchrotron X-ray Photoemission Spectroscopy (SXPS), indicate a significant acceleration of copper oxidation in the presence of iodide anions in the electrolyte. A surface confined supersaturation with mobile CuI monomers first leads to the formation of a 2D-CuI film via nucleation and growth of a Cu/I-bilayer on-top of a pre-adsorbed iodide monolayer. Structurally, this 2D-CuI film is closely related to the (111) plane of crystalline CuI (zinc blende type). Interestingly, this film causes no significant passivation of the copper surface. In an advanced stage of copper dissolution a transition from the 2D- to a 3D-CuI growth mode can be observed.

Seismic response analysis of reinforced concrete frames including soil flexibility

  • Jayalekshmi, B.R.;Poojary, V.G. Deepthi;Venkataramana, Katta;Shivashankar, R.
    • Structural Engineering and Mechanics
    • /
    • v.48 no.1
    • /
    • pp.1-16
    • /
    • 2013
  • The seismic response of RC space frame structures with isolated footing resting on a shallow soil stratum on rock is presented in this paper. Homogeneous soil stratum of different stiffness in the very soft to stiff range is considered. Soil, footing and super structure are considered to be the parts of an integral system. A finite element model of the integrated system is developed and subjected to scaled acceleration time histories recorded during two different real earthquakes. Dynamic analysis is performed using mode superposition method of transient analysis. A parametric study is conducted to investigate the effect of flexibility of soil in the dynamic behaviour of low-rise building frames. The time histories and Fourier spectra of roof displacement, base shear and structural response quantities of the space frame on compliant base are presented and compared with the fixed base condition. Results indicate that the incorporation of soil flexibility is required for the realistic estimate of structural seismic response especially for single storey structures resting on very soft soil.

Floor Impact Noise Level for Concrete Slab Integrated with Floor Finishing Layers (콘크리트 슬래브와 바닥 상부구조가 일체된 바닥구조의 바닥충격음)

  • Mun, Dae Ho;Oh, Yang Ki;Jeong, Gab Cheol;Park, Hong Gun
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.26 no.2
    • /
    • pp.130-140
    • /
    • 2016
  • Floating floor is most commonly used at apartment houses in Korea for thermal insulation and reducing impact noise. But it in proven that the floating floor is not effective for reducing the floor impact noise in low frequency range. In most cases, impact sound pressure level under 63 Hz frequency band were actually increased by the resonance of resilient material, lightweight concrete and the finishing mortar installed on it. In this paper, an integrated floor system consist of 70 mm light weight concrete and 40 mm finishing mortar successively installed on the concrete slab was suggested to avoid the resonance. Integrated floor system increases total flexural stiffness and mass per unit area. The natural frequencies of first and second vibration mode were increased and acceleration response and floor impact sound level was decreased in all measurement range.

Optical Assembly and Fabrication of a Micro-electron Column (마이크로 전자렌즈의 광학적 정렬과 조립)

  • Park, Jong-Seon;Jang, Won-Kweon;Kim, Ho-Seob
    • Korean Journal of Optics and Photonics
    • /
    • v.17 no.4
    • /
    • pp.354-358
    • /
    • 2006
  • A silicon lens and an insulator of pyrex, components of a micro-electron column, should be assembled by aligning and stacking simultaneously. An optical alignment of a diffraction beam and a laser welding were employed for the assembly of a source lens and an Einzel lens with precision within $\pm$4% for the maximum aperture size. The experimental condition for optical alignment and laser welding are explained. Anodic bonding was used to assist in stacking lenses. A micro-electron column of smaller apertures assembled with precise alignment and fabrication was tested with a current image of a Cu grid of 9$\mu$m in linewidth, and showed a higher resolution in acceleration mode.

High Performance Speed Control of Switched Reluctance Motor

  • Song, Byeang-Seab;Yoon, Yong-Ho;Choi, Jun-Hyuk;Kim, Jun-Ho;Won, Chung-Yuen
    • Proceedings of the KIPE Conference
    • /
    • 2001.10a
    • /
    • pp.457-461
    • /
    • 2001
  • Advantages of switched reluctance motor(SRM) drives make it an attractive candidate for replacing adjustable speed ac and dc drives in both industrial and consumer applications. Furthermore, a simple, low cost and robust SRM drive can be efficiently operated in the hostile environment of an automobile. Generally, the speed control of SRM has a large step change or large torque reference, the output of its PI controller is often saturated. When this happens, the integral state is not consistent with the SRM input, while may give rise to the windup phenomenon. This paper proposes anti-windup control method for SRM speed control system by hysteresis current controlled asymmetry bridge converter. The experimental results show that the speed response has much improved performance, such as a small overshoot and fast settling time at the acceleration and particulary deceleration period with braking mode.

  • PDF

Dynamic Finite Element Modeling and Structural Vibration Analysis of a Gyrocopter (자이로콥터의 동적 유한요소모델링 및 구조진동해석)

  • Jung, Se-Un;Yang, Yong-Jun;Kim, Hyun-Jung;Je, Sang-Eon;Cho, Tae-Hwan;Kim, Dong-Hyun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2005.05a
    • /
    • pp.813-820
    • /
    • 2005
  • In this study, finite element modeling and structural vibration analyses of a gyrocopter have been conducted considering dynamic hub-loads due to rotating blades. For this research, 3D CATIA models for most mechanical parts are exactly prepared and assembled into the final aircraft configuration. Then the dynamic finite element model including several non-structural parts are constructed based on the exact 3D CAD data. Computational structural dynamics technique based on finite element method is applied using both MSC/NASTRAN and developed in-house code which can largely reduce the pre and postprocessing time of general transient dynamic analyses. Modal based transient and frequency response analyses are used to efficiently investigate vibration characteristics. The results include natural frequency comparison for different fuel and pilot conditions, fundamental natural mode shapes, frequency responses and transient acceleration responses of the present gyrocopter model.

  • PDF

Control Characteristics of ER engine mount considering Temperature Variation (온도 변화에 따른 ER 엔진마운트의 제어 특성)

  • Song, Hyun-Jeong;Choi, Seung-Bok
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2005.05a
    • /
    • pp.180-183
    • /
    • 2005
  • The engine mount of vehicle systems is role of support engine mass and isolate noise and vibration from engine disturbance forces. One of attractive candidates to achieve this goai is to utilize a semi-active ER engine mount. By applying this, we can effectively control damping force and hence the noise and vibration by just controlling the intensity of electric field. However, control performance of the engine mount may be very sensitive to temperature variation during engine operation. In this work, we Investigate dynamic performances of ER engine mount with respect to the temperature variation. In order to undertake this, a flow-mode type of ER engine mount is designed and manufactured. Displacement transmissibility is experimentally and numerically evaluated as a function of the electric field. The ER engine mount is then incorporated with full-vehicle model in order to investigate vibration control performance. After formulating the governing equation of motion, a semi-active controller is designed. The controller is implemented through a hardware-in-the-loop simulation (HILS), and control responses such as acceleration level at various engine speeds are evaluated in the frequency and time domains.

  • PDF