The Experts below are selected from a list of 348 Experts worldwide ranked by ideXlab platform
Junmin Wang - One of the best experts on this subject based on the ideXlab platform.
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tutorial of model based powertrain and Aftertreatment System control design and implementation
Advances in Computing and Communications, 2015Co-Authors: Guoming G Zhu, Junmin Wang, Zongxuan Sun, Xiang ChenAbstract:This paper introduces the needs for applying model-based control techniques to vehicle powertrain and Aftertreatment Systems. A tutorial overview of model-based control techniques and methodologies for modern powertrain and Aftertreatment Systems is presented and compared with the traditional approaches. The control-oriented powertrain and Aftertreatment System modeling techniques are also addressed along with their real-time simulation requirement for HIL (hardware-in-the-loop) simulations. The application examples of the model-based control of internal combustion engine, transmission, and Aftertreatment Systems are given in detail.
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cycle based optimal nox emission control of selective catalytic reduction Systems with dynamic programming algorithm
Fuel, 2015Co-Authors: Hui Zhang, Yan Chen, Junmin Wang, Shichun YangAbstract:Abstract In this work, we investigate the cycle-based optimal NO x emission control for Diesel engine selective catalytic reduction (SCR) Systems. The optimization is carried out based on the SCR model and the SCR is assumed to be a continuous stirred tank reactor during the modeling. Considering the main chemical reactions inside an SCR cell, a three-state nonlinear model is obtained and the System parameters are determined by using the experimental data. The states of the nonlinear model consist of the NO x concentration, the ammonia concentration, and the ammonia coverage ratio. Though there are considerable works on the SCR dosing control in the literature, the optimal control strategy applied to the SCR Systems has been rarely studied. The global optimality in the SCR dosing control can be used as a benchmark and evaluate the performance of other designed controllers. Moreover, it can be employed to find the limit of NO x conversion efficiency of a specific SCR Aftertreatment System and select the minimal volume of the SCR catalyst cell. Therefore, it is quite meaningful to study the optimal NO x emission control of SCR Systems via the dynamic programming approach. For the optimization, the challenges arise from the following aspects: (1) Due to the System stiffness, we cannot find an equivalent discrete-time model for the traditional dynamic programming, that is, the traditional dynamic programming algorithm is not applicable. (2) The computational load is relatively too heavy and a personal PC is not affordable. To deal with the existing challenges, we propose the dynamic programming algorithm based on the continuous-time SCR model. The computational load is adjustable in terms of the accuracy. The proposed algorithm is then applied to the SCR System for the NO x emission reduction. And the algorithm validation is carried out based on the US06 test cycle. It infers from the optimization results and the comparison, the prescribed ammonia slip constraint is satisfied and the tailpipe NO x emission is optimized.
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model predictive control of integrated hybrid electric powertrains coupled with Aftertreatment Systems
Volume 2: Dynamic Modeling and Diagnostics in Biomedical Systems; Dynamics and Control of Wind Energy Systems; Vehicle Energy Management Optimization;, 2014Co-Authors: Junfeng Zhao, Junmin WangAbstract:For hybrid electric vehicles (HEVs), especially for diesel-electric hybrid vehicles, the low exhaust gas temperature induced by the hybridization and fuel economy optimization will bring significant impact on the performance of the exhaust gas Aftertreatment Systems, and may consequently lead to violation of the tailpipe emission constraints. To investigate the influence of diesel powertrain hybridization on the Aftertreatment System and tailpipe emissions, an integrated HEV model is established by incorporating the thermodynamics models of the Aftertreatment Systems. This comprehensive model is able to predict engine-out nitrogen oxides (NOx) concentration, exhaust gas temperature, and to describe the temperature dynamics in the Aftertreatment Systems. A static map of selective catalytic reduction (SCR) System temperature-dependent de-NOx efficiency is utilized, so that the tailpipe NOx can be predicted. To investigate the tradeoff between fuel consumption and emissions for diesel HEV with Aftertreatment Systems, a preliminary study is carried out on optimally balancing both aspects via a model predictive control scheme. This controller is designed with an explicit consideration of HEV tailpipe NOx emission constraint. The simulation results show that the HEV tailpipe NOx emissions can be regulated by slightly sacrificing the fuel economy.Copyright © 2014 by ASME
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integrated diesel engine and selective catalytic reduction System active no x control for fuel economy improvement
American Control Conference, 2013Co-Authors: Pingen Chen, Junmin WangAbstract:Diesel engine technologies have gone through significant progresses in the past decade. Though the tailpipe NOx and particulate matter emissions have been reduced to a large extent by the applications of after-treatment Systems such as selective catalytic reduction (SCR) Systems and Diesel particulate filters, engine fuel economy usually needs to be compromised considerably to achieve appropriate engine-out emissions. Most of the current Diesel engine control studies focus only on the Diesel engines themselves, while most of the current Aftertreatment controls are limited in the scope of Aftertreatment Systems alone. The opportunities of further improving the overall powertrain System performance by considering the engine and Aftertreatment System in an integrative way have been rarely exploited. In this paper, a new framework for integrated control of both engine and Aftertreatment System is devised. A backstepping-based active NOx control method is proposed by treating the engine-out NOx concentration as a control input for the ammonia coverage ratio control of a two-cell SCR System. Simulation results based on the UDDS driving cycle show that up to 5.86% of engine fuel consumption can be reduced without a significant penalty on the tailpipe emissions.
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no and no2 concentration modeling and observer based estimation across a diesel engine Aftertreatment System
Journal of Dynamic Systems Measurement and Control-transactions of The Asme, 2011Co-Authors: Mingfeng Hsieh, Junmin WangAbstract:This paper presents an experimentally validated control-oriented model and an observer for diesel oxidation catalyst (DOC)-diesel particulate filter (DPF) System in the context of exhaust gas NO and NO 2 concentration estimations. NO and NO 2 have different reaction characteristics within DPF and selective catalytic reduction (SCR) Systems, two most promising diesel engine Aftertreatment Systems. Although the majority of diesel engine-out NO 2 emissions is NO, the commonly used DOC located upstream of a DPF and a SCR can convert a considerable amount of NO to NO 2 . Knowledge of the NO/NO 2 ratio in exhaust gas is thus meaningful for the control and diagnosis of DPF and SCR Systems. Existing onboard NO x sensors cannot differentiate NO and NO 2 , and such a sensory deficiency makes separate considerations of NO and NO 2 in SCR control design challenging. To tackle this problem, a control-oriented dynamic model, which can capture the main NO and NO 2 dynamics from engine-out, through DOC, and to DPF, was developed. Due to the computational limitation concerns, DOC and DPF are assumed to be standard continuously stirred tank reactors in order to obtain a OD ordinary differential equation model. Based on the model, an observer, with the measurement from a commercially available NO x sensor, was designed to estimate the NO and NO 2 concentrations in the exhaust gas along the Aftertreatment Systems. The stability of the observer was shown through a Lyapunov analysis assisted by insight into the System characteristics. The control-oriented model and the observer were validated with engine experimental data and the measured NO/NO 2 concentrations by a Horiba gas analyzer. Experimental results show that the model can accurately predict the main engine-out/DOC/DPF NO/NO 2 dynamics very well in semisteady-state tests. For the proposed observer, the predictions converge to the model values and estimate the NO and NO 2 concentrations in the Aftertreatment System well.
Mingfeng Hsieh - One of the best experts on this subject based on the ideXlab platform.
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no and no2 concentration modeling and observer based estimation across a diesel engine Aftertreatment System
Journal of Dynamic Systems Measurement and Control-transactions of The Asme, 2011Co-Authors: Mingfeng Hsieh, Junmin WangAbstract:This paper presents an experimentally validated control-oriented model and an observer for diesel oxidation catalyst (DOC)-diesel particulate filter (DPF) System in the context of exhaust gas NO and NO 2 concentration estimations. NO and NO 2 have different reaction characteristics within DPF and selective catalytic reduction (SCR) Systems, two most promising diesel engine Aftertreatment Systems. Although the majority of diesel engine-out NO 2 emissions is NO, the commonly used DOC located upstream of a DPF and a SCR can convert a considerable amount of NO to NO 2 . Knowledge of the NO/NO 2 ratio in exhaust gas is thus meaningful for the control and diagnosis of DPF and SCR Systems. Existing onboard NO x sensors cannot differentiate NO and NO 2 , and such a sensory deficiency makes separate considerations of NO and NO 2 in SCR control design challenging. To tackle this problem, a control-oriented dynamic model, which can capture the main NO and NO 2 dynamics from engine-out, through DOC, and to DPF, was developed. Due to the computational limitation concerns, DOC and DPF are assumed to be standard continuously stirred tank reactors in order to obtain a OD ordinary differential equation model. Based on the model, an observer, with the measurement from a commercially available NO x sensor, was designed to estimate the NO and NO 2 concentrations in the exhaust gas along the Aftertreatment Systems. The stability of the observer was shown through a Lyapunov analysis assisted by insight into the System characteristics. The control-oriented model and the observer were validated with engine experimental data and the measured NO/NO 2 concentrations by a Horiba gas analyzer. Experimental results show that the model can accurately predict the main engine-out/DOC/DPF NO/NO 2 dynamics very well in semisteady-state tests. For the proposed observer, the predictions converge to the model values and estimate the NO and NO 2 concentrations in the Aftertreatment System well.
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development and experimental studies of a control oriented scr model for a two catalyst urea scr System
Control Engineering Practice, 2011Co-Authors: Mingfeng Hsieh, Junmin WangAbstract:Abstract This paper presents the development and experimental studies of a complete selective catalytic reduction (SCR) System control-oriented model of a two-catalyst SCR System with onboard NO x and ammonia sensors. SCR catalysts have been popularly regarded as effective means for NO x emission control in medium- and heavy-duty vehicles in recent years. However, control of urea dosing upstream of the SCR Systems still remains a challenge in the field mainly due to the complicated SCR dynamics and limited/inaccurate feedback information. A control-oriented SCR model is thus indispensable for SCR control Systems. A variety of experimental tests were examined using a Diesel engine-Aftertreatment System consisting of a diesel oxidation catalyst (DOC)/diesel particulate filter (DPF), two-SCR catalysts (Fe-Zeolite type) in series, three NO x sensors, and two NH 3 sensors. By utilizing multiple emission sensors and the two-catalyst SCR setup, the sensor properties and SCR System dynamics were studied. Grounded in the experimental investigations and the physical insights, a control-oriented model for a complete SCR System was developed and validated with experimental data.
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design and experimental validation of an extended kalman filter based nox concentration estimator in selective catalytic reduction System applications
Control Engineering Practice, 2011Co-Authors: Mingfeng Hsieh, Junmin WangAbstract:Abstract This paper presents an extended Kalman filter (EKF) based approach of integrating NO x and NH 3 sensors to estimate the NO x concentrations in Diesel engine selective catalytic reduction (SCR) Aftertreatment Systems. NO x sensors have been commonly used by vehicles for Aftertreatment System control and onboard diagnostics (OBD) purposes. However, most currently available NO x sensors are cross-sensitive to ammonia. Based on the experimental observations and physical inferences, the cross-sensitivity characteristics may change with temperature and is hard to be predicted by a model. This feature limits the applications of NO x sensors on urea-SCR Systems where ammonia is the reductant for NO x conversions. Grounded in the insight into SCR dynamics and NO x sensor properties, a novel approach of using an extended Kalman filter to estimate the actual exhaust gas NO x concentration was proposed. The estimator was examined by NO x measurements from a Horiba gas analyzer under different engine operating conditions. The experimental results show that the EKF-based approach can significantly improve the accuracy of NO x concentration measurements from the original NO x sensor readings.
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design and experimental validation of an extended kalman filter based nox concentration estimator in selective catalytic reduction System applications
Control Engineering Practice, 2011Co-Authors: Mingfeng Hsieh, Junmin WangAbstract:Abstract This paper presents an extended Kalman filter (EKF) based approach of integrating NO x and NH 3 sensors to estimate the NO x concentrations in Diesel engine selective catalytic reduction (SCR) Aftertreatment Systems. NO x sensors have been commonly used by vehicles for Aftertreatment System control and onboard diagnostics (OBD) purposes. However, most currently available NO x sensors are cross-sensitive to ammonia. Based on the experimental observations and physical inferences, the cross-sensitivity characteristics may change with temperature and is hard to be predicted by a model. This feature limits the applications of NO x sensors on urea-SCR Systems where ammonia is the reductant for NO x conversions. Grounded in the insight into SCR dynamics and NO x sensor properties, a novel approach of using an extended Kalman filter to estimate the actual exhaust gas NO x concentration was proposed. The estimator was examined by NO x measurements from a Horiba gas analyzer under different engine operating conditions. The experimental results show that the EKF-based approach can significantly improve the accuracy of NO x concentration measurements from the original NO x sensor readings.
Masaaki Okubo - One of the best experts on this subject based on the ideXlab platform.
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a pilot scale experiment for total marine diesel emission control using ozone injection and nonthermal plasma reduction
IEEE Transactions on Industry Applications, 2015Co-Authors: Takuya Kuwahara, Tomoyuki Kuroki, Keiichiro Yoshida, Kenichi Hanamoto, Kazutoshi Sato, Masaaki OkuboAbstract:Due to the fact that it is difficult to fulfill the recent stringent regulations governing marine diesel engine emission by means of combustion improvement alone, an effective Aftertreatment technology is required to achieve the efficient simultaneous removal of $\hbox{NO}_{\rm x} $ and particulate matter (PM) . In the present study, we designed and investigated an effective Aftertreatment System that employs a combination of ozone injection and nonthermal plasma (NTP) reduction for a marine diesel engine. The proposed technology offers the advantage of not requiring precious-metal catalysts and harmful heavy-metal catalysts as well as urea solution. In this Aftertreatment System, PM in the exhaust gas is first captured by a ceramic diesel particulate filter. Subsequently, the deposited PM is oxidized and removed by NTP-induced ozone injection. After the PM treatment, $\hbox{NO}_{\rm x} $ in the exhaust gas is treated by adsorption followed by NTP-combined desorption and reduction processes. These processes are repeated periodically, and total emission control is achieved. Since the deposited PM and the desorbed $\hbox{NO}_{\rm x} $ are treated at a high-concentration state by ozone and oxygen-lean NTP, a higher performance for total marine diesel emission control is recorded. The maximum efficiencies of $\hbox{NO}_{\rm x} $ and PM reduction were 94% and 95%, respectively.
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pilot scale Aftertreatment using nonthermal plasma reduction of adsorbed nox in marine diesel engine exhaust gas
Plasma Chemistry and Plasma Processing, 2014Co-Authors: Takuya Kuwahara, Tomoyuki Kuroki, Keiichiro Yoshida, Kenichi Hanamoto, Kazutoshi Sato, Masaaki OkuboAbstract:Regulations governing marine diesel engine NOx emissions have recently become more stringent. As it is difficult to fulfill these requirements by combustion improvements alone, effective Aftertreatment technologies are needed to achieve efficient NOx reductions. In this study, we develop an effective NOx-reduction Aftertreatment System for a marine diesel engine that employs combined nonthermal plasma (NTP) and adsorption. Compared with selective catalytic reduction, the proposed technology offers the advantages of not requiring a urea solution or harmful heavy-metal catalysts and low operating temperatures of less than 150 °C. The NOx reduction comprises repeated adsorption and desorption flow processes using NTP combined with NOx adsorbents made of MnOx–CuO. High concentrations of NOx are treated by NTP after NOx adsorption and desorption, and this Aftertreatment System demonstrates excellent energy efficiencies of 161 g(NO2)/kWh, which fulfills the most recent International Maritime Organization emission NOx standards in the Tier II–III regulations for 2016 and requires only 4.3 % of the engine output power.
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diesel emission control System using combined process of nonthermal plasma and exhaust gas components recirculation
Thin Solid Films, 2009Co-Authors: Keiichiro Yoshida, Tomoyuki Kuroki, Masaaki OkuboAbstract:Abstract A NOx Aftertreatment System, using nonthermal plasma (NTP) reduction and exhaust gas components' recirculation, is investigated. A pilot-scale System is applied to a stationary diesel engine. In this System, NOx is first removed by adsorption, and subsequently, the adsorbent is regenerated by thermal desorption. NOx desorbed is reduced by using nitrogen NTP. Moreover, NOx, CO2, and water vapor recirculated into the engine intake reduce NOx. In this study, approximately 57% of the NOx of the exhaust (NOx: 240–325 ppm, flow rate = 300 NL/min) can be continuously treated for 58 h. A System energy efficiency of 120 g (NO2)/kWh is obtained.
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continuous operation of commercial scale plasma chemical Aftertreatment System of smoke tube boiler emission with oxidation reduction potential and ph control
Thin Solid Films, 2008Co-Authors: Tomoyuki Kuroki, Hidekatsu Fujishima, Keiichi Otsuka, Tomohiro Ito, Masaaki Okubo, Toshiaki Yamamoto, Keiichiro YoshidaAbstract:Abstract NO x removal from an actual boiler flue gas is investigated using an indirect plasma and chemical hybrid System comprising a commercial ozonizer and an Na 2 SO 3 chemical scrubber. A high NO x removal efficiency in the continuous operation of a commercial-scale apparatus is achieved by controlling pH and oxidation reduction potential (ORP) and injecting additional Na 2 SO 3 and NaOH aqueous solutions into the scrubber sump when required. Ozone injection is demonstrated to be extremely effective for NO oxidation. The relation between the ORP and NO x removal efficiency, which is essential for the optimal operation of this System, is obtained.
Maruthi Narasinga Rao Devarakonda - One of the best experts on this subject based on the ideXlab platform.
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model based control System design in a urea scr Aftertreatment System based on nh3 sensor feedback
International Journal of Automotive Technology, 2009Co-Authors: Maruthi Narasinga Rao Devarakonda, John H. Johnson, Gordon G Parker, Vadim StrotsAbstract:This paper presents preliminary control System simulation results in a urea-selective catalytic reduction (SCR) Aftertreatment System based on NH3 sensor feedback. A four-state control-oriented lumped parameter model is used to analyze the controllability and observability properties of the urea-SCR plant. A model-based estimator is designed via simulation and a control System is developed with design based on a sliding mode control framework. The control System based on NH3 sensor feedback is analyzed via simulation by comparing it to a control System developed based on NOx sensor feedback. Simulation results show that the NH3 sensor-based strategy performs very similarly in comparison to a NOx sensor-based strategy. The control System performance metrics for NOx index, urea index, urea usage, and NH3 slip suggest that the NOx sensor can be a potential alternative to a NOx sensor for urea-SCR control applications.
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model based estimation and control System development in a urea scr Aftertreatment System
SAE International Journal of Fuels and Lubricants, 2008Co-Authors: Maruthi Narasinga Rao Devarakonda, John H. Johnson, Gordon G Parker, Vadim Strots, Shyam SanthanamAbstract:In this paper, a model-based linear estimator and a nonlinear control law for an Fe-zeolite ureaselective catalytic reduction (SCR) catalyst for heavy duty diesel engine applications is presented. The novel aspect of this work is that the relevant species, NO, NO2 and NH3 are estimated and controlled independently. The ability to target NH3 slip is important not only to minimize urea consumption, but also to reduce this unregulated emission. Being able to discriminate between NO and NO2 is important for two reasons. First, recent Fe-zeolite catalyst studies suggest that NOx reduction is highly favored by the NO2 based reactions. Second, NO2 is more toxic than NO to both the environment and human health. The estimator and control law are based on a 4-state model of the urea-SCR plant. A linearized version of the model is used for state estimation while the full nonlinear model is used for control design. An experimentally validated, higher order simulation is used to evaluate the performance of the closed loop System. For the cases considered, the control strategy uses less urea, produces less NH3 slip, and less tailpipe NOx than a similar strategy where NO and NO2 are assumed as all NO during estimation and control law implementation.
Shyam Santhanam - One of the best experts on this subject based on the ideXlab platform.
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model based estimation and control System development in a urea scr Aftertreatment System
SAE International Journal of Fuels and Lubricants, 2008Co-Authors: Maruthi Narasinga Rao Devarakonda, John H. Johnson, Gordon G Parker, Vadim Strots, Shyam SanthanamAbstract:In this paper, a model-based linear estimator and a nonlinear control law for an Fe-zeolite ureaselective catalytic reduction (SCR) catalyst for heavy duty diesel engine applications is presented. The novel aspect of this work is that the relevant species, NO, NO2 and NH3 are estimated and controlled independently. The ability to target NH3 slip is important not only to minimize urea consumption, but also to reduce this unregulated emission. Being able to discriminate between NO and NO2 is important for two reasons. First, recent Fe-zeolite catalyst studies suggest that NOx reduction is highly favored by the NO2 based reactions. Second, NO2 is more toxic than NO to both the environment and human health. The estimator and control law are based on a 4-state model of the urea-SCR plant. A linearized version of the model is used for state estimation while the full nonlinear model is used for control design. An experimentally validated, higher order simulation is used to evaluate the performance of the closed loop System. For the cases considered, the control strategy uses less urea, produces less NH3 slip, and less tailpipe NOx than a similar strategy where NO and NO2 are assumed as all NO during estimation and control law implementation.