A Study of Vehicle Equipped with Non-Throttling S.I. Engine with Early Intake Valve Closing Mechanism

Urata, Yasuhiro; Umiyama, Hidezo; Shimizu, Kiyoshí; Fujiyoshi, Yoshihiro; Sono, Hiroshi; Fukuo, Koichi

doi:10.4271/930820

Cited by 51 publications

(10 citation statements)

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“…We show that the instability is intrinsic to the unthrottled operation and speci"c to the camless actuation used to achieve the unthrottled operation. It is, indeed, well known in the automotive community that &stable' unthrottled engine operation is di$cult to achieve during low load, and in particular, during idle conditions [7,8]. With this work we substantiate this observation and develop the necessary framework to analyse and control the process.…”

Section: Introductionmentioning

confidence: 52%

“…We con"rm this signi"cance in Section 5 where we show that the linearized open-loop speed dynamics with the camless breathing IVDP N has a stable pole very close to the imaginary axis, whereas the P N open-loop dynamics in the conventional engine ( is the air-bypass valve position or electronic throttle angle) are stable with poles far into the open left-half plane (OLHP). Reference to the absence of the self-regulating properties of the intake manifold dynamics can also be found in the experimental study by Urata et al [8].…”

Section: Breathing Dynamicsmentioning

confidence: 87%

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Inherent limitations and control design for camless engine idle speed dynamics

Wang

Stefanopoulou

Smith

2001

Intl J Robust & Nonlinear

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SUMMARYThe idle speed control problem of a spark-ignited engine equipped with a camless valvetrain is considered. The camless valvetrain allows control of the individual intake and exhaust valves of each cylinder and can be used to achieve unthrottled operation, and consequently, optimize the engine performance. We formulate the speed control problem for this engine and show that it exhibits unstable open-loop behaviour with a signi"cant delay in the feedback loop. The instability is intrinsic to the unthrottled operation and speci"c to the camless actuation used to achieve the unthrottled operation. The delay is caused by the discrete combustion process and the sensor/computer/actuator interface. We demonstrate the inherent system limitations associated with the unstable dynamics and the delay and provide insight on the structural (plant) design that can alleviate these limitations. Finally, stabilizing controllers using classical and modern robust design techniques are presented and tested on a nonlinear simulation model.

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Section: Introductionmentioning

confidence: 52%

Section: Breathing Dynamicsmentioning

confidence: 87%

Inherent limitations and control design for camless engine idle speed dynamics

Wang

Stefanopoulou

Smith

2001

Intl J Robust & Nonlinear

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“…Dresner a al [ 9] cites a 50% increase in low speed torque and an average torque increase over the entire speed range of 10%. Urata et al [52] and Hatano et al [15] report 10% and 15% improvement, respectively, in the low speed torque. Kreuter a al [24] obtained 33% higher IMEP at 1000 rpm due mainly to higher volumetric efficiency and a minimized residual gas fraction.…”

Section: Variable Intake Timingmentioning

confidence: 94%

“…Numerous camshaft-based variable-valve mechanisms have been developed [1,.9, 10,11,14,18,26,27,29,30,33,38,47,54]. A recent search on U.S. patent data base with the phrase 'variable valve timing" resulted in 196 patents.…”

Section: Background and Technical Objectivesmentioning

confidence: 99%

Electrohydraulic Valve-trains for Direct Injection Compression Ignition Camless Engine Operations - Phase I Project Final Report

Tsao¹,

Tai²,

Stubbs³

et al. 2000

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“…The pumping mean effective pressure (PMEP) was reduced for both EIVC and LIVC compared to throttled SI. Urata et al [19] developed Hydraulic Variable-valve Train (HVT) that can be closed at arbitrary timings and capable of withstanding engine speeds up to 6000rpm, they reported reduced pumping loss of 80% and about 7% reduced fuel consumption, they also observed lower in-cylinder compression temperature and increased combustion fluctuation under low load. More recently, Patel et al [20] reported that the EIVC could be used to improve part-load fuel efficiency in a direct injection gasoline engine.…”

Section: Introductionmentioning

confidence: 95%