• Title, Summary, Keyword: Virtual Mode Synthesis and Simulation

Search Result 5, Processing Time 0.036 seconds

Shock Response Prediction of a Low Altitude Earth Observation Satellite During Launch Vehicle Separation

  • Lee, Dae-Oen;Han, Jae-Hung;Jang, Hae-Won;Woo, Sung-Hyun;Kim, Kyung-Won
    • International Journal of Aeronautical and Space Sciences
    • /
    • v.11 no.1
    • /
    • pp.49-57
    • /
    • 2010
  • Several pyrotechnic devices are employed over the course of satellite's missions, generally for the separation of structural subsystems and deployment of appendages. Firing of pyrotechnic devices results in impulsive loads characterized by high peak acceleration and high frequency content which can cause failures of various flight hardware elements and small components. Thus, accurate prediction of acceleration level in various components of spacecraft due to pyrotechnic devices is important. In this paper, two methods for pyroshock prediction, an empirical model and statistical energy analysis in conjunction with virtual mode synthesis, are applied to predict shock response of a low altitude earth observation satellite during launch vehicle separation. The predicted results are then evaluated through comparison with the shock test results.

A Real-time Multibody Vehicle Dynamics and Control Model for a Virtual Reality Intelligent Vehicle Simulator (가상현실 지능형 차량 시뮬레이터를 위한 실시간 다물체 차량 동역학 및 제어모델)

  • 김성수;손병석;송금정;정상윤
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.11 no.4
    • /
    • pp.173-179
    • /
    • 2003
  • In this paper, a real-time multibody vehicle dynamics and control model has been developed for a virtual reality intelligent vehicle simulator. The simulator consists of low PCs for a virtual reality visualization system, vehicle dynamics and control analysis system a control loading system, and a network monitoring system. Virtual environment is created by 3D Studio Max graphic tool and OpenGVS real-time rendering library. A real-time vehicle dynamics and control model consists of a control module based on the sliding mode control for adaptive cruise control and a real-time multibody vehicle dynamics module based on the subsystem synthesis method. To verify the real-time capability of the model, cut-in, cut-out simulations have been carried out.

Auditory Interaction Design By Impact Sound Synthesis for Virtual Environment (충돌음 합성에 의한 가상환경의 청각적 인터랙션 디자인)

  • Nam, Yang-Hee
    • The Journal of the Korea Contents Association
    • /
    • v.13 no.5
    • /
    • pp.1-8
    • /
    • 2013
  • Focused on the fact that sound is one of the important sensory cues delivering situations such as impact, this paper proposes an auditory interaction design approach for virtual environment. Based on a few sampling of basic material sound for various materials such as steel, rubber, and glass, the proposed method enables design transformations of the basic sound by allowing modification of mode gains that characterize natural sound for the material. In real-time virtual environment, it also provides simulation of modified sound according to the change of impact situation's perceptual properties such as colliding objects' size, hardness, contacting area, and speed. The test results on cognition experiment for discriminating objects' materials and impact situation by sound showed the feasibility of proposed auditory interaction design method.

VLSI Implementation of Forward Error Control Technique for ATM Networks

  • Padmavathi, G.;Amutha, R.;Srivatsa, S.K.
    • ETRI Journal
    • /
    • v.27 no.6
    • /
    • pp.691-696
    • /
    • 2005
  • In asynchronous transfer mode (ATM) networks, fixed length cells of 53 bytes are transmitted. A cell may be discarded during transmission due to buffer overflow or a detection of errors. Cell discarding seriously degrades transmission quality. The quality degradation can be reduced by employing efficient forward error control (FEC) to recover discarded cells. In this paper, we present the design and implementation of decoding equipment for FEC in ATM networks based on a single parity check (SPC) product code using very-large-scale integration (VLSI) technology. FEC allows the destination to reconstruct missing data cells by using redundant parity cells that the source adds to each block of data cells. The functionality of the design has been tested using the Model Sim 5.7cXE Simulation Package. The design has been implemented for a $5{\times}5$ matrix of data cells in a Virtex-E XCV 3200E FG1156 device. The simulation and synthesis results show that the decoding function can be completed in 81 clock cycles with an optimum clock of 56.8 MHz. A test bench was written to study the performance of the decoder, and the results are presented.

  • PDF