• 제목/요약/키워드: CVVT(continuous variable valve timing)

검색결과 4건 처리시간 0.017초

Sensitivity of Hot Film Flow Meter in Four Stroke Gasoline Engine

  • Lee, Gangyoung;Lee, Cha--Myung;Park, Simsoo;Youngjin Cho
    • Journal of Mechanical Science and Technology
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    • 제18권2호
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    • pp.286-293
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    • 2004
  • The air fuel ratios of current gasoline engines are almost controlled by several air flow meters. When CVVT (Continuous Variable Valve Timing) is applied to a gasoline engine for higher engine performance, the MAP (Manifold Absolute Pressure) sensor is difficult to follow the instantaneous air fuel ratio due to the valve timing effect. Therefore, a HFM (Hot Film Flow Meter) is widely used for measuring intake air flow in this case. However, the HFMs are incapable of indicating to reverse flow, the oscillation of intake air flow has an negative effect on the precision of the HFM. Consequently, the various duct configurations in front of the air flow sensor affect the precision of HFM sensitivity. This paper mainly focused on the analysis of the reverse flow, flow fluctuation in throttle upstream and the geometry of intake system which influence the HFM measurement.

NONLINEAR MODEL-BASED CONTROL OF VANE TYPE CONTINUOUS VARIABLE VALVE TIMING SYSTEM

  • Son, M.;Lee, M.;Lee, K.;SunWoo, M.;Lee, S.;Lee, C.;Kim, W.
    • International Journal of Automotive Technology
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    • 제8권5호
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    • pp.555-562
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    • 2007
  • The Variable Valve Timing(VVT) system for high performance is a key technology used in newly developed engines. The system realizes higher torque, better fuel economy, and lower emissions by allowing an additional degree of freedom in valve timing during engine operation. In this study, a model-based control method is proposed to enable a fast and precise VVT control system that is robust with respect to manufacturing tolerances and aging. The VVT system is modeled by a third-order nonlinear state equation intended to account for nonlinearities of the system. Based on the model, a controller is designed for position control of the VVT system. The sliding mode theory is applied to controller design to overcome model uncertainties and unknown disturbances. The experimental results suggest that the proposed sliding mode controller is capable of improving tracking performance. In addition, the sliding mode controller is robust to battery voltage disturbance.

RSM을 이용한 CVVT용 전동기 코깅토크 저감 설계 (Cogging Torque Reduction Design for CVVT Using Response Surface Methodology)

  • 김재의;김동민;박수환;홍정표
    • 전기학회논문지
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    • 제65권12호
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    • pp.2183-2188
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    • 2016
  • This paper deals with the design process for an outer-rotor-type surface-mounted permanent magnet synchronous motor (SPMSM) used in continuous variable valve timing (CVVT) systems in automobiles with internal combustion engines. When the same size, outer-rotor-type SPMSMs generate larger torque and more stable than inner-rotor-type SPMSMs. For the initial design, space harmonic analysis (SHA) is used. In order to minimize the cogging torque, an optimization was conducted using Response Surface Methodology (RSM). At the end of the paper, Finite Element Analysis (FEA) is performed to verify the performance of the optimum model.

하이브리드 시스템 시뮬레이터용 엔진 모듈 개발과 최적화에 관한 연구 (Development and Optimization of Engine Module for Hybrid System Simulator)

  • 전대일;공호정;황인구;명차리;박심수
    • 한국자동차공학회논문집
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    • 제18권1호
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    • pp.14-22
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    • 2010
  • Hybrid Electronic Vehicle (HEV) is one of the solutions of high oil price and environment problem. Recently, study of HEV is important for automobile industry. However HEV has a lot of components and there are many cases for assembling, it's impossible to test results from assembling by using real vehicles. To solve this problem, hybrid system simulator is required. The purpose of this study is to develop and optimize of engine module for hybrid system simulator. The commercial 1-D engine simulation program, WAVE is used to get the engine capacity and performance data and 1-D simulation model of base engine is compared with engine experiment results. Using the data, the engine module is developed based on the MATLAB Simulink. There are blocks of base engine, Single-CVVT engine and Dual-CVVT engine. The effect of acceleration and deceleration is applied to each engine block. In addition, the control and processing logics for CIS technology are developed. Finally the simulator operates FTP-72 mode test.