The Experts below are selected from a list of 3297 Experts worldwide ranked by ideXlab platform
Tielong Shen - One of the best experts on this subject based on the ideXlab platform.
-
adaptive internal model based control of the rgf using online map learning and statistical feedback law
IEEE-ASME Transactions on Mechatronics, 2020Co-Authors: Jinwu Gao, Yahui Zhang, Jiangyan Zhang, Tielong ShenAbstract:Residual Gas Fraction (RGF) defined as the ratio of Residual Gas mass to the mass of total Gas burned in one cylinder is an important variable for managing combustion quality and combustion mode. This article proposes an adaptive internal model control (AIMC) based framework that synthesizes on-board map calibration and statistical feedback criterion to track a desired RGF target. The model structure of plant dynamics (or its inverse) in AIMC is derived as a cascade combination of a steady mapping and a parameter-varying variable valve timing (VVT) dynamics (or inverse). The on-board map calibration algorithm is employed to adapt the operating-point-dependent steady mapping since the system behavior may change. Then, a VVT compensatory controller in the AIMC was designed based on the online identification of the parameter-varying VVT dynamics model and its inverse. Moreover, a statistical criterion, namely, the hypothesis test was creatively introduced in the feedback channel of the AIMC to filter out the stochastic noise of the RGF. The experiment results show that the AIMC-based framework significantly improves the RGF tracking performance in both steady and transient states.
-
logical control scheme with real time statistical learning for Residual Gas Fraction in ic engines
Science in China Series F: Information Sciences, 2018Co-Authors: Xun Shen, Tielong ShenAbstract:In this paper, an optimal control scheme for reducing the fluctuation of Residual Gas Fraction (RGF) under variational operating condition is developed by combining stochastic logical system approach with statistical learning method. The method estimating RGF from measured in-cylinder pressure is introduced firstly. Then, the stochastic properties of the RGF are analyzed according to statistical data captured by conducting experiments on a test bench equipped with a L4 internal combustion engine. The influences to the probability distribution of the RGF from both control input and environment parameters are also analyzed. Based on the statistical analysis, a stochastic logical transient model is adopted for describing cyclic behavior of the RGF. Optimal control policy maps for different fixed operating conditions are calculated then. Besides, a statistical learning-based method is applied to learn the probability density function (PDF) of RGF in the real-time which is used to adjust the control MAP based on logical optimization. The whole optimal control policy map is obtained based on Gaussian process regression with consideration of statistical information of RGF. Finally, the performance of the proposed method is experimentally validated.
-
policy iteration approach to control Residual Gas Fraction in ic engines under the framework of stochastic logical dynamics
IEEE Transactions on Control Systems and Technology, 2017Co-Authors: Tielong ShenAbstract:This brief investigates the cycle-to-cycle transient behavior of the Residual Gas Fraction (RGF) in terms of systems theory and proposes a multivalued logic-based optimal control strategy for the attenuation of RGF fluctuation. First, an in-cylinder pressure-based method for measuring RGF is provided, and the stochastic properties of the RGF are examined based on statistical data obtained by conducting experiments on a full-scale internal combustion engine test bench. Based on the observation of the experiment, a stochastic logical transient model is proposed to represent the cycle-to-cycle transient behavior of the RGF. Then, an optimal feedback control law, which targets the rejection of the RGF fluctuation, is derived using the policy iteration algorithm. Finally, the experimental result is demonstrated to show the effectiveness of the proposed optimal control law.
-
Effect of Transient Residual Gas Fraction for Gasoline Engines
IFAC Proceedings Volumes, 2016Co-Authors: Kota Sata, Akira Ohata, Junichi Kako, Tielong ShenAbstract:Abstract The Residual Gas Fraction (RGF) greatly affects misfiring, the heat release pattern of combustion, the NOx emission, knocking, the auto-ignition and the spark advance control. There is a possibility that a RGF estimation improves the accuracy of engine control. This paper describes a transient RGF estimation based on a physical model and the effect of RGF on combustion and transient air fuel ratio. This study shows the auto-correlation function takes negative values at k = 1 (k: engine cycle number) and the Residual Gas causes the dynamics of air-fuel ratio calculated from the composition of burned Gas.
-
a stochastic logical system approach to model and optimal control of cyclic variation of Residual Gas Fraction in combustion engines
Applied Thermal Engineering, 2016Co-Authors: Yuhu Wu, Madan Kumar, Tielong ShenAbstract:Abstract In four stroke internal combustion engines, Residual Gas from the previous cycle is an important factor influencing the combustion quality of the current cycle, and the Residual Gas Fraction (RGF) is a popular index to monitor the influence of Residual Gas. This paper investigates the cycle-to-cycle transient behavior of the RGF in the view of systems theory and proposes a multi-valued logic-based control strategy for attenuation of RGF fluctuation. First, an in-cylinder pressure sensor-based method for measuring the RGF is provided by following the physics of the in-cylinder transient state of four-stroke internal combustion engines. Then, the stochastic property of the RGF is examined based on statistical data obtained by conducting experiments on a full-scale Gasoline engine test bench. Based on the observation of the examination, a stochastic logical transient model is proposed to represent the cycle-to-cycle transient behavior of the RGF, and with the model an optimal feedback control law, which targets on rejection of the RGF fluctuation, is derived in the framework of stochastic logical system theory. Finally, experimental results are demonstrated to show the effectiveness of the proposed model and the control strategy.
Zoran Filipi - One of the best experts on this subject based on the ideXlab platform.
-
real time calculation of Residual Gas Fraction utilising the polytropic coefficient of compression
International Journal of Powertrains, 2017Co-Authors: Mark Hoffman, Robert Prucka, Zoran FilipiAbstract:An algorithm is developed to serve as a stand-alone Residual Gas Fraction diagnostic tool which utilises the polytropic coefficient of compression and an inverse thermodynamic algorithm to determine trapped Residual Gas Fraction. The model requires: 1) cylinder pressure resolved with at least crank angle resolution; 2) high accuracy manifold pressure (preferably crank angle resolved and measured very near the intake port; 3) equivalence ratio of the fuel-air mixture; 4) mass estimations of cylinder contents other than Residual, namely air mass, and fuel mass; 5) cylinder geometry (bore, stroke, clearance volume); 6) timing of the intake valve closing event. This work outlines the algorithm methodology and assesses its performance on both an ensemble averaged and individual cycle basis. However, the current RGF calculation methodology is shown to produce unacceptable levels of error on an individual cycle basis. Suggestions are provided for algorithm enhancement.
-
Understanding the effect of operating conditions on thermal stratification and heat release in a homogeneous charge compression ignition engine
Applied Thermal Engineering, 2017Co-Authors: Benjamin Lawler, Sotirios Mamalis, Satyum Joshi, Joshua Lacey, Orgun A. Guralp, Paul M. Najt, Zoran FilipiAbstract:Abstract Thermal stratification of the unburned charge prior to ignition plays a significant role in governing the heat release rates in a homogeneous charge compression ignition (HCCI) engine. A deep understanding of the conditions affecting thermal stratification is necessary for actively managing HCCI burn rates and expanding its operating range. To that end, a single-cylinder Gasoline-fueled HCCI engine was used to characterize the relationship between key operating conditions, such as intake temperature, Residual Gas Fraction, air-to-fuel ratio, and swirl, and thermal stratification. The recently developed Thermal Stratification Analysis was applied to calculate the unburned temperature distribution prior to ignition from heat release. A comparison between re-induction of exhaust Gas with an air-to-fuel ratio of 24:1 and air dilution with an air-to-fuel ratio of 43:1 shows that the presence of internal Residuals increases the burn duration by 34% and broadens the temperature distribution by as much as 15%. The results from an intake temperature and combustion phasing sweep at an air-to-fuel ratio of 20:1 show that heat release rates increase with advancing CA50 phasing; however, the temperature distributions broaden by 48% when comparing the most advanced to most retarded cases. To add further insight by removing the effect of combustion phasing, an equivalence ratio sweep is compared to an intake temperature sweep. It is shown that a significant part of the broadening of the distributions can be attributed exclusively to the increased intake temperature which elevates the maximum TDC temperature while leaving the wall region unaffected. However, combustion phasing plays a role as well, with earlier combustion phasing being responsible for an additional broadening of the temperature distribution. The addition of swirl elongates the burn duration by broadening the temperature distribution, with this effect being slightly larger at earlier combustion phasings. However, swirl significantly increases heat transfer losses and reduces efficiencies by as much as 1.8 percentage points. Finally, a load sweep with compensation to ensure constant combustion phasing indicates that higher loads result in increased heat release rates and narrower temperature distributions by as much as 20%.
Ocktaeck Lim - One of the best experts on this subject based on the ideXlab platform.
-
estimation the effect of exhaust Residual Gas on effective release energy no x emission and the influence of engine parameters on exhaust Residual Gas Fraction of a v twin engine
2020 5th International Conference on Smart and Sustainable Technologies (SpliTech), 2020Co-Authors: Xuan Khoa Nguyen, Ocktaeck LimAbstract:this paper estimates and summarized the parameters which affect the exhaust Residual Gases Fraction and the influence of Residual Gas Fraction on engine effective release energy, NOx emission which weren’t presented yet in the previous articles. It is complicated to determine the Residual Gas Fraction ratio, the effective release energy under the various testing conditions from the experiments. Through combined experimental and simulation methods we eliminated certain above drawbacks. From results of the research, we thoroughly investigated the effects of engine speed, air-fuel ratio, valve overlap, combustion duration, intake port diameter-bore ratio, and bore-stroke ratio on the internal exhaust Residual Gases Fraction.
-
Comparative Study of the Effective Release Energy, Residual Gas Fraction, and Emission Characteristics with Various Valve Port Diameter-Bore Ratios (VPD/B) of a Four-Stroke Spark Ignition Engine
Energies, 2020Co-Authors: Nguyen Xuan Khoa, Ocktaeck LimAbstract:In this research, the Residual Gas, peak firing pressure increase, and effective release energy were completely investigated. To obtain this target, the experimental system is installed with a dynamo system and a simulation model was setup. Through combined experimental and simulation methods, the drawbacks of the hardware optimization method were eliminated. The results of the research show that the valve port diameter-bore ratio (VPD/B) has a significant effect on the Residual Gas, peak firing pressure increase, and effective release energy of a four-stroke spark ignition engine. In this research, the engine was performed at 3000 rpm and full load condition. Following increased IPD/B ratio of 0.3–0.5. The intake port and exhaust port diameter has a contrary effect on engine volumetric efficiency, the Residual Gas ratio increase 27.3% with larger intake port and decrease 18.6% with larger exhaust port. The engine will perform optimal thermal efficiency when the trapped Residual Gas Fraction ratio is from 13% to 14%. The maximum effective release energy was 0.45 kJ at 0.4 intake port-bore ratio, and 0.451 kJ at 0.35 exhaust port-bore ratio. The NOx emission increases until achieved a maximum value after that decrease even VPD/B was still increasing. With a VPD/B ratio of 0.35 to 0.4, the engine works without the misfiring.
Shuqian Wang - One of the best experts on this subject based on the ideXlab platform.
-
quantitative investigation the influences of the injection timing under single and double injection strategies on performance combustion and emissions characteristics of a gdi si engine fueled with Gasoline ethanol blend
Fuel, 2020Co-Authors: Shuqian Wang, Jingping Liu, Xiongbo Duan, Yiqun Liu, Genmiao GuoAbstract:Abstract An experimental investigation of the single injection strategy and double injection strategy on the combustion phasing, performance and emissions characteristics in the GDI engine fueled with E10 was conducted. The effective expansion ratio (EER), effective expansion efficiency (EEE) and Residual Gas Fraction (RGF) characteristics were further investigated under single injection strategy and double injection strategy. The result indicated that under the single injection strategy, the change trends of the EER and EEE were the same as the Gasoline effective brake thermal efficiency (GEBTE). The maximum value of the EER and EEE were 7.86 and 0.513, and the maximum decrease magnitude of EER and EEE was 8.86% and 3.63%, respectively. However, the change trend of RGF was opposite to BTE, and its maximum increase magnitude of RGF was 4.72%. In addition, with the increase of the second end of injection timing, the peak combustion pressure (PCP), maximum heat release rate (HRR) and mean in-cylinder temperature gradually increased. The position of the maximum PCP and maximum HRR closed to the TDC. The CA50 combustion location advanced and the combustion duration shortened, and thereby increasing the EER, EEE and GEBTE. Finally, comparing the single injection strategy with the double injection strategy, the GEBTE decreased by 5.09%, while the NOx and HC emissions sharply decreased by 54.46%, 31.81%, respectively.
-
Experimental investigation on the influences of exhaust Gas recirculation coupling with intake tumble on Gasoline engine economy and emission performance
Energy Conversion and Management, 2016Co-Authors: Jianqin Fu, Guohui Zhu, Yan Xia, Jingping Liu, Feng Zhou, Shuqian WangAbstract:To improve the economy and emission performance of Gasoline engine under part load, the approach of exhaust Gas recirculation coupling with intake tumble was investigated by bench testing. Based on a naturally aspirated Gasoline engine, the sweeping test of exhaust Gas recirculation rate was conducted in two intake modes (with/without intake tumble), and the parameters related to engine heat-work conversion process and emission performance were measured. Through comparing and analyzing the measured data, the effects of exhaust Gas recirculation coupling with intake tumble on Gasoline engine economy and emission performance were revealed. The results show that pumping loss decreases gradually while in-cylinder Residual Gas Fraction increases linearly with the exhaust Gas recirculation rate increasing; the high-pressure cycle efficiency ascends with exhaust Gas recirculation rate increasing due to the decrease of heat transfer loss and exhaust Gas energy loss. Thus, the improvement of indicated thermal efficiency is the superposition of double benefits of low-pressure cycle and high-pressure cycle. At 1600 r/min and 2.94 bar, the indicated thermal efficiency can be increased by 4.29%. With the increase of exhaust Gas recirculation rate, nitrogen oxide emissions almost fall linearly, but hydrocarbon and carbonic oxide emissions have no obvious change in the effective range of exhaust Gas recirculation rate. The biggest advantage of intake tumble is that it can extend the effective range of exhaust Gas recirculation rate. As a result, the potential of energy conservation and emission reduction of exhaust Gas recirculation is largely improved.
Benjamin Lawler - One of the best experts on this subject based on the ideXlab platform.
-
Understanding the effect of operating conditions on thermal stratification and heat release in a homogeneous charge compression ignition engine
Applied Thermal Engineering, 2017Co-Authors: Benjamin Lawler, Sotirios Mamalis, Satyum Joshi, Joshua Lacey, Orgun A. Guralp, Paul M. Najt, Zoran FilipiAbstract:Abstract Thermal stratification of the unburned charge prior to ignition plays a significant role in governing the heat release rates in a homogeneous charge compression ignition (HCCI) engine. A deep understanding of the conditions affecting thermal stratification is necessary for actively managing HCCI burn rates and expanding its operating range. To that end, a single-cylinder Gasoline-fueled HCCI engine was used to characterize the relationship between key operating conditions, such as intake temperature, Residual Gas Fraction, air-to-fuel ratio, and swirl, and thermal stratification. The recently developed Thermal Stratification Analysis was applied to calculate the unburned temperature distribution prior to ignition from heat release. A comparison between re-induction of exhaust Gas with an air-to-fuel ratio of 24:1 and air dilution with an air-to-fuel ratio of 43:1 shows that the presence of internal Residuals increases the burn duration by 34% and broadens the temperature distribution by as much as 15%. The results from an intake temperature and combustion phasing sweep at an air-to-fuel ratio of 20:1 show that heat release rates increase with advancing CA50 phasing; however, the temperature distributions broaden by 48% when comparing the most advanced to most retarded cases. To add further insight by removing the effect of combustion phasing, an equivalence ratio sweep is compared to an intake temperature sweep. It is shown that a significant part of the broadening of the distributions can be attributed exclusively to the increased intake temperature which elevates the maximum TDC temperature while leaving the wall region unaffected. However, combustion phasing plays a role as well, with earlier combustion phasing being responsible for an additional broadening of the temperature distribution. The addition of swirl elongates the burn duration by broadening the temperature distribution, with this effect being slightly larger at earlier combustion phasings. However, swirl significantly increases heat transfer losses and reduces efficiencies by as much as 1.8 percentage points. Finally, a load sweep with compensation to ensure constant combustion phasing indicates that higher loads result in increased heat release rates and narrower temperature distributions by as much as 20%.