A particulate matter On-Board Diagnostics method based on temperature sensing is demonstrated. The concept applies a detection filter downstream of the main particulate filter and a flow diversion pipe. A small fraction of the main exhaust flow is diverted through the detection filter. In case the main soot filter has some leakage, soot will collect on the detection filter where it reduces the filter's permeability. As a result the diverted flow is reduced. This effect is sensed by a temperature sensor placed downstream of the detection filter because the change of diverted mass flow results in a change of heating rate. This principle allows particulate filter diagnostics based on cost-effective and readily available sensing technology.Comprehensive diagnostics software is developed to interpret and assess the temperature signal. The developed diagnostics software detects particulate filter filtration inefficiency and performs plausibility checks. The concept is demonstrated using an instrumented test vehicle with purposely damaged particulate filter. The diagnostics prove successful in detecting a filtration inefficiency fault that leads to particulate matter emissions close to the 12 mg/km 2017 Euro 6 OBD Threshold Limit.

This study presents an integrated energy and emission management strategy for an Euro-VI diesel engine with Waste Heat Recovery (WHR) system. This Integrated Powertrain Control (IPC) strategy optimizes the CO2-NOx trade-off by minimizing the operational costs associated with fuel and AdBlue consumption. The main contribution of this work is that the effect of tailpipe emissions and WHR dynamics are included in the control design. In a simulation study, the potential of this strategy is demonstrated over a World Harmonized Transient Cycle. These results are compared with a baseline engine control strategy. This study shows that slow WHR dynamics strongly affect the engine performance: neglecting these dynamics in the control design leads to unacceptable high tailpipe NOx emissions. By applying the IPC strategy, an additional 2.8% CO2 reduction is achieved within the NOx emission limit compared to the baseline strategy.

This study presents an integrated energy and emission management strategy which minimizes the operational costs over the study test cycle. This Integrated Powertrain Control (IPC) strategy deals with high system complexity and exploits the synergy between engine-aftertreatment systems by following a model-based approach. The potential of this integrated approach is demonstrated for a new application: an Euro-VI diesel engine with Waste Heat Recovery system. Main contribution of this work is to include the emission constraints in the control design for this application. In a simulation study, the performance of the presented IPC strategy is compared with a baseline engine control strategy over the World Harmonized Transient Cycle. It is shown that the IPC strategy explicitly deals with the NOx tailpipe emission target and simultaneously reduces CO2 emissions by 2.8% compared to the baseline strategy.

Selective catalytic reduction (SCR) is a promising diesel after treatment technology that enables low nitrogen oxides (NO x ) tailpipe emissions with relatively low fuel consumption. Future emission legislation is pushing the boundaries for SCR control systems to achieve high NO x conversion within a tailpipe ammonia (NH 3 ) slip constraint, and to provide robustness to meet in-use compliance requirements. This work presents a new adaptive control strategy that uses an ammonia feedback sensor and an online ammonia storage model. Experimental validation on a 12-liter heavy-duty diesel engine with a 34-liter Zeolite SCR catalyst shows good performance and robustness against urea under- and over-dosage for both the European steady-state and transient test cycles. The new strategy is compared with a NO x sensor-based control strategy with cross-sensitivity compensation. It proved to be superior in terms of transient adaptation and taking an NH 3 slip constraint into account.

A new cost-based control strategy is presented that optimizes engine-aftertreatment performance under all operating conditions. This Integrated Emission Management strategy minimizes fuel consumption within the set emission limits by on-line adjustment of air management based on the actual state of the exhaust gas aftertreatment system. Following a model-based approach, Integrated Emission Management offers a framework for future control strategy development. This approach alleviates calibration complexity, since it allows to make optimal trade-offs in an operational cost sense. The potential of the presented cost-optimal control strategy is demonstrated for a modern heavy-duty Euro VI engine. The studied diesel engine is equipped with cooled EGR, Variable Geometry Turbocharger, and a DPF-SCR aftertreatment system. A simulation study shows that the proposed Integrated Emission Management strategy accomplishes 2% to 3% reduction in fuel consumption and operating costs compared to a baseline strategy. Further potential benefits include reduced heat rejection associated with the EGR system and reduced DPF regeneration frequency. © 2011 SAE International.

Lkw-Hersteller konzentrieren sich hinsichtlich der Euro-VI-Emissionswertanforderungen auf die Abgasrückführung und deren Kombination mit harnstoffbasierter selektiver katalytischer Reduktion. TNO hat ein Konzept entwickelt, das den Weg für eine Alternativlösung bereitet, die von selektiver katalytischer Reduktion als Haupttechnologie zur NOx-Minderung ausgeht. Dieses Konzept ermöglicht einen geringeren Kraftstoffverbrauch ohne größere Folgen für die Auslegung von Motor und Kühlanlage. Zusammen mit Haldor Topsøe, Yara und Grundfos untersuchte TNO das NOx-Reduktionspotenzial auf dem Prüfstand.

To meet Euro VI emission targets for heavy-duty applications, truck manufacturers concentrate on Exhaust Gas Recirculation (EGR) and its combination with urea-based Selective Catalytic Reduction (SCR). TNO developed a concept that opens the route for an alternative solution which relies on SCR as the main technology for NOx abatement. This concept offers potential fuel benefits in combination with low impact on engine design and cooling equipment. Together with Haldor Topsøe, Yara and Grundfos, TNO examined the achievable NOx emission reduction on an engine dynamometer.

Reaching EUROVI Heavy Duty emission limits will result in more testing time for developing control and OBD algorithms than to reach EUROV emissions. It is likely that these algorithms have to be adapted for a WHTC (World Heavy Duty Transient Cycle) for EUROVI. This cycle when started cold can only be performed a limited times a day on the engine testbench, because of the cooling down time. The development time and cost increases to reach EUROVI emission levels. Accurate simulation tools can reduce the time and costs by reducing the amount of tests required on the testbench. In order to use simulation tools to develop pre calibrations, the models must be fitted and validated. This paper will focus on the fit process of an SCR (Selective Catalytic Reduction) model. A unique test procedure has been developed to characterize an SCR catalyst using an engine testbench in ±2 days. This data is used in an automatic SCR fit tool to obtain the model parameters in a few days. The result is a model that predicts the NO, NO 2 and NH 3 SCR out concentration accurately. The fitted SCR model can predict tailpipe NO x emissions for a wide range of test cycles within 10 % (see Table 5). The validated model is used to develop and calibrate SCR control and OBD algorithms.

A promising SCR-only solution is presented to meet post-2010 NOx emission targets for heavy duty applications. The proposed concept is based on an engine from a EURO IV SCR application, which is considered optimal with respect to fuel economy and costs. The addition of advanced SCR after treatment comprising a standard and a close-coupled SCR catalyst offers a feasible emission solution, especially suited for EURO VI.In this paper, results of a simulation study are presented. This study concentrates on optimizing SCR deNO(x) performance. Simulation results of cold start FTP and WHTC test cycles are presented to demonstrate the potential of the close-coupled SCR concept. Comparison with measured engine out emissions of an EGR engine shows that a close-coupled SCR catalyst potentially has NOx reduction performance as good as EGR. Practical issues regarding the use of an SCR catalyst in close-coupled position will be addressed, as well as engine and exhaust layout.For comparison, the requirements of a US 2010/EURO VI compliant high EGR engine are discussed: base engine design, heat rejection, fuel injection equipment, turbo charging and fuel economy. From this study, it is concluded that the SCR-only approach leads to a less expensive engine design with better fuel economy and lower PM emissions.

With the increasing demands on driveability, fuel efficiency and emissions, it becomes essential to optimize the overall performance of future powertrains. Therefore, a system approach is required. In this study, the Integrated Powertrain Control concept is presented, which exploits the synergy between engine, driveline and aftertreatment system. To illustrate the benefits of this concept, the combination of a diesel engine, hybrid driveline and DPF system is studied for a distribution truck. Focus is on minimizing the required energy and components for DPF regeneration. For electric DPF heating, electric heating for DOC light off, and idle-stop cases, the impact on fuel consumption and on DPF temperature are determined during DPF regeneration. It is shown that the operating envelop of the DPF can be extended, even to idle.

Selective Catalytic Reduction (SCR) is the dominant solution for meeting future NOx reduction regulations for heavy-duty diesel powertrains. SCR systems benefit from closed-loop control if an appropriate exhaust gas sensor were available. An ammonia sensor has recently been developed for use as a feedback element in closed-loop control of urea dosing in a diesel SCR aftertreatment system. Closed-loop control of SCR dosing enables the SCR system to be robust against disturbances and to meet conformity of production (COP) and in-use compliance norms.

Selective Catalytic Reduction (SCR) is the dominant solution for meeting future NOx reduction regulations for heavy-duty diesel powertrains. SCR systems benefit from closed-loop control if an appropriate exhaust gas sensor were available. An ammonia sensor has recently been developed for use as a feedback element in closed-loop control of urea dosing in a diesel SCR aftertreatment system. Closed-loop control of SCR dosing enables the SCR system to be robust against disturbances and to meet conformity of production (COP) and in-use compliance norms. The ammonia sensor is based on a non-equilibrium electrochemical principle and outputs emf signals. The sensor performs well when tested in a diesel engine exhaust environment and has minimum cross interference with CO, HC, NO, NO2, SO2, H2O and O2. Previous work, done in a simulation environment, demonstrated that an ammonia sensor provides the optimal feedback for urea dosing control algorithms in closed-loop SCR systems. A model-based SCR control strategy deploying an ammonia feedback sensor demonstrated high NOx conversion, low NH3 slip and good robustness against disturbances. In this paper, FTP, ETC and ESC test data will be presented confirming these results. NOx conversions as high as 91% are measured in combination with 30% urea injection error and a 25 ppm NH3 slip constraint. Test results using the Delphi ammonia sensor for control are compared with test results utilizing a commercially available NOx sensor for control.

To meet 2010 emission targets, optimal SCR system performance is required. In addition, attention has to be paid to in-use compliance requirements. Closed-loop control seems an attractive option to meet the formulated goals. This study deals with the potential and limitations of closed-loop SCR control. High NO x conversion in combination with acceptable NH 3 slip can be realized with an open-loop control strategy. However, closed-loop control is needed to make the SCR system robust for urea dosage inaccuracy, catalyst ageing and NO x engine-out variations. Then, the system meets conformity of production and in-use compliance norms. To demonstrate the potential of closed-loop SCR control, a NO x sensor based control strategy with crosssensitivity compensation is compared with an adaptive surface coverage/NH 3 slip control strategy and an openloop strategy. The adaptive surface coverage/NH 3 slip control strategy shows best performance over simulated ESC and ETC cycles. SCR catalyst dynamics, time delay in the urea injection and maximum NH 3 slip targets limit the performance of closed-loop SCR control. If new reagent dosage systems and future catalyst technology are able to relieve these limitations, closed-loop control has the potential to reduce the calibration effort and to improve the transient control performance.