Prediction of NOx considering NO and NO2 for a CI engine

Nitrogen oxides (NO x) are one of the main harmful emissions from diesel engines. Regulations on emissions are becoming more stringent; consequently, research should aim at reducing both engine-out NO x and tail-pipe NO x emissions. Exhaust gas recirculation is mainly used to reduce engine-out NO x emissions. After-treatment methods such as lean NO x trap systems and selective catalyst reduction are used to minimize tail-pipe NO x emissions. Real-time feedback control during transient conditions can further reduce these emissions and be utilized when information about real-time engine-out NO x emissions is available. It would be helpful to evaluate the proportion of NO2 in NO x emissions because the conversion efficiency of an after-treatment system is affected by temperature and the NO-to-NO2 ratio. Therefore, a semi-empirical NO x model considering NO and NO2 separately was developed for a diesel engine in this study. The NO estimation model was established based on the extended Zeldovich mechanism. The NO2 estimation model focused on chemical reactions between NO and other species and was based on formation and decomposition mechanisms. This NO x model can contribute to the cost reduction of engine systems by replacing existing NO x sensors and can also be applied to real-time feedback control strategies to minimize NO x emissions.

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Application of real-time feedback control strategies based on effluent NH4-N and NO X -N concentrations in an A2/O process

Korean Journal of Chemical Engineering ◽

10.1007/s11814-013-0084-x ◽

2013 ◽

Vol 30 (8) ◽

pp. 1578-1587 ◽

Cited By ~ 4

Author(s):

Hyosoo Kim ◽

Yejin Kim ◽

Trung Quang Hoang ◽

Gyeongdong Baek ◽

Sungshin Kim ◽

...

Keyword(s):

Feedback Control ◽

Real Time ◽

Control Strategies

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Multiple input-multiple output adaptive feedback control strategies for the active headrest system: design and real-time implementation

International Journal of Adaptive Control and Signal Processing ◽

10.1002/acs.778 ◽

2003 ◽

Vol 17 (10) ◽

pp. 785-800 ◽

Cited By ~ 14

Author(s):

Marek Pawelczyk

Keyword(s):

Feedback Control ◽

System Design ◽

Real Time ◽

Control Strategies ◽

Multiple Input Multiple Output ◽

Adaptive Feedback ◽

Adaptive Feedback Control ◽

Multiple Input ◽

Input Multiple Output

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Pollution based real time control strategies for combined sewer systems

Water Science & Technology ◽

10.2166/wst.1997.0688 ◽

1997 ◽

Vol 36 (8-9) ◽

pp. 331-336 ◽

Cited By ~ 8

Author(s):

Gabriela Weinreich ◽

Wolfgang Schilling ◽

Ane Birkely ◽

Tallak Moland

Keyword(s):

Real Time ◽

Control Strategies ◽

Ammonia Nitrogen ◽

Simple Extension ◽

Real Time Control ◽

Time Control ◽

Sewer Systems ◽

Receiving Waters ◽

Tunnel System

This paper presents results from an application of a newly developed simulation tool for pollution based real time control (PBRTC) of urban drainage systems. The Oslo interceptor tunnel is used as a case study. The paper focuses on the reduction of total phosphorus Ptot and ammonia-nitrogen NH4-N overflow loads into the receiving waters by means of optimized operation of the tunnel system. With PBRTC the total reduction of the Ptot load is 48% and of the NH4-N load 51%. Compared to the volume based RTC scenario the reductions are 11% and 15%, respectively. These further reductions could be achieved with a relatively simple extension of the operation strategy.

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Feedback control to delay or advance linear loss of stability in planar Poiseuille flow

Proceedings of the Royal Society of London. Series A: Mathematical and Physical Sciences ◽

10.1098/rspa.1994.0142 ◽

1994 ◽

Vol 447 (1930) ◽

pp. 299-312 ◽

Cited By ~ 21

Keyword(s):

Feedback Control ◽

Poiseuille Flow ◽

Control Strategies ◽

Linear Stability Theory ◽

Flow Instabilities ◽

Loss Of Stability ◽

Stress Sensors ◽

Shear Stress Sensors ◽

Linear Loss ◽

Adjacent Wall

By using linear stability theory, we demonstrate theoretically that the critical Reynolds number for the loss of stability of planar Poiseuille flow can be significantly increased or decreased through the use of feedback control strategies which enhance or suppress disturbance dissipating mechanisms in the flow. The controller studied here consists of closely packed, wall mounted, shear stress sensors and thermoelectric actuators. The sensors detect flow instabilities and direct the actuators to alter the fluid’s viscosity by modulating the adjacent wall temperature in such a way as to suppress or enhance flow instabilities. Results are presented for water and air flows.

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Real‐time feedback control of voice in cochlear implant recipients

Laryngoscope Investigative Otolaryngology ◽

10.1002/lio2.481 ◽

2020 ◽

Vol 5 (6) ◽

pp. 1156-1162

Author(s):

Anirudh Gautam ◽

Jason A. Brant ◽

Michael J. Ruckenstein ◽

Steven J. Eliades

Keyword(s):

Feedback Control ◽

Cochlear Implant ◽

Real Time

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Power Hardware-in-the-Loop-Based Performance Analysis of Different Converter Controllers for Fast Active Power Regulation in Low-Inertia Power Systems

Energies ◽

10.3390/en14113274 ◽

2021 ◽

Vol 14 (11) ◽

pp. 3274

Author(s):

Jose Rueda Torres ◽

Zameer Ahmad ◽

Nidarshan Veera Kumar ◽

Elyas Rakhshani ◽

Ebrahim Adabi ◽

...

Keyword(s):

Performance Evaluation ◽

Power Systems ◽

Real Time ◽

Control Strategies ◽

Active Power ◽

Power Electronic ◽

Hardware In The Loop ◽

Digital Controllers ◽

Power Regulation ◽

The Impact

Future electrical power systems will be dominated by power electronic converters, which are deployed for the integration of renewable power plants, responsive demand, and different types of storage systems. The stability of such systems will strongly depend on the control strategies attached to the converters. In this context, laboratory-scale setups are becoming the key tools for prototyping and evaluating the performance and robustness of different converter technologies and control strategies. The performance evaluation of control strategies for dynamic frequency support using fast active power regulation (FAPR) requires the urgent development of a suitable power hardware-in-the-loop (PHIL) setup. In this paper, the most prominent emerging types of FAPR are selected and studied: droop-based FAPR, droop derivative-based FAPR, and virtual synchronous power (VSP)-based FAPR. A novel setup for PHIL-based performance evaluation of these strategies is proposed. The setup combines the advanced modeling and simulation functions of a real-time digital simulation platform (RTDS), an external programmable unit to implement the studied FAPR control strategies as digital controllers, and actual hardware. The hardware setup consists of a grid emulator to recreate the dynamic response as seen from the interface bus of the grid side converter of a power electronic-interfaced device (e.g., type-IV wind turbines), and a mockup voltage source converter (VSC, i.e., a device under test (DUT)). The DUT is virtually interfaced to one high-voltage bus of the electromagnetic transient (EMT) representation of a variant of the IEEE 9 bus test system, which has been modified to consider an operating condition with 52% of the total supply provided by wind power generation. The selected and programmed FAPR strategies are applied to the DUT, with the ultimate goal of ascertaining its feasibility and effectiveness with respect to the pure software-based EMT representation performed in real time. Particularly, the time-varying response of the active power injection by each FAPR control strategy and the impact on the instantaneous frequency excursions occurring in the frequency containment periods are analyzed. The performed tests show the degree of improvements on both the rate-of-change-of-frequency (RoCoF) and the maximum frequency excursion (e.g., nadir).

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Power Hardware-in-the-Loop: Response of Power Components in Real-Time Grid Simulation Environment

Energies ◽

10.3390/en14030593 ◽

2021 ◽

Vol 14 (3) ◽

pp. 593

Author(s):

Moiz Muhammad ◽

Holger Behrends ◽

Stefan Geißendörfer ◽

Karsten von Maydell ◽

Carsten Agert

Keyword(s):

Real Time ◽

Power Distribution ◽

Control Strategies ◽

Power Grid ◽

Energy System ◽

Hardware In The Loop ◽

Distribution Grid ◽

Compensation Strategy ◽

Software Environment ◽

The Real

With increasing changes in the contemporary energy system, it becomes essential to test the autonomous control strategies for distributed energy resources in a controlled environment to investigate power grid stability. Power hardware-in-the-loop (PHIL) concept is an efficient approach for such evaluations in which a virtually simulated power grid is interfaced to a real hardware device. This strongly coupled software-hardware system introduces obstacles that need attention for smooth operation of the laboratory setup to validate robust control algorithms for decentralized grids. This paper presents a novel methodology and its implementation to develop a test-bench for a real-time PHIL simulation of a typical power distribution grid to study the dynamic behavior of the real power components in connection with the simulated grid. The application of hybrid simulation in a single software environment is realized to model the power grid which obviates the need to simulate the complete grid with a lower discretized sample-time. As an outcome, an environment is established interconnecting the virtual model to the real-world devices. The inaccuracies linked to the power components are examined at length and consequently a suitable compensation strategy is devised to improve the performance of the hardware under test (HUT). Finally, the compensation strategy is also validated through a simulation scenario.

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RTLIO: Real-Time LiDAR-Inertial Odometry and Mapping for UAVs

Sensors ◽

10.3390/s21123955 ◽

2021 ◽

Vol 21 (12) ◽

pp. 3955

Author(s):

Jung-Cheng Yang ◽

Chun-Jung Lin ◽

Bing-Yuan You ◽

Yin-Long Yan ◽

Teng-Hu Cheng

Keyword(s):

Feedback Control ◽

Real Time ◽

High Frequency ◽

Indoor Environment ◽

Indoor Localization ◽

Sampling Rate ◽

Outdoor Environment ◽

Position Accuracy ◽

Graph Optimization ◽

Pose Graph Optimization

Most UAVs rely on GPS for localization in an outdoor environment. However, in GPS-denied environment, other sources of localization are required for UAVs to conduct feedback control and navigation. LiDAR has been used for indoor localization, but the sampling rate is usually too low for feedback control of UAVs. To compensate this drawback, IMU sensors are usually fused to generate high-frequency odometry, with only few extra computation resources. To achieve this goal, a real-time LiDAR inertial odometer system (RTLIO) is developed in this work to generate high-precision and high-frequency odometry for the feedback control of UAVs in an indoor environment, and this is achieved by solving cost functions that consist of the LiDAR and IMU residuals. Compared to the traditional LIO approach, the initialization process of the developed RTLIO can be achieved, even when the device is stationary. To further reduce the accumulated pose errors, loop closure and pose-graph optimization are also developed in RTLIO. To demonstrate the efficacy of the developed RTLIO, experiments with long-range trajectory are conducted, and the results indicate that the RTLIO can outperform LIO with a smaller drift. Experiments with odometry benchmark dataset (i.e., KITTI) are also conducted to compare the performance with other methods, and the results show that the RTLIO can outperform ALOAM and LOAM in terms of exhibiting a smaller time delay and greater position accuracy.

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Model Predictive Control Strategies to Activate the Energy Flexibility for Zones with Hydronic Radiant Systems

Energies ◽

10.3390/en14041195 ◽

2021 ◽

Vol 14 (4) ◽

pp. 1195

Author(s):

Ali Saberi Derakhtenjani ◽

Andreas K. Athienitis

Keyword(s):

Control Strategies ◽

High Price ◽

Electricity Prices ◽

Peak Demand ◽

Heating Systems ◽

Electrical Grid ◽

Demand Reduction ◽

The Cost ◽

Floor System ◽

Radiant Floor Heating

This paper presents control strategies to activate energy flexibility for zones with radiant heating systems in response to changes in electricity prices. The focus is on zones with radiant floor heating systems for which the hydronic pipes are located deep in the concrete and, therefore, there is a significant thermal lag. A perimeter zone test-room equipped with a hydronic radiant floor system in an environmental chamber is used as a case study. A low order thermal network model for the perimeter zone, validated with experimental measurements, is utilized to study various control strategies in response to changes in the electrical grid price signal, including short term (nearly reactive) changes of the order of 10–15 min notice. An index is utilized to quantify the building energy flexibility with the focus on peak demand reduction for specific periods of time when the electricity prices are higher than usual. It is shown that the developed control strategies can aid greatly in enhancing the zone energy flexibility and minimizing the cost of electricity and up to 100% reduction in peak power demand and energy consumption is attained during the high-price and peak-demand periods, while maintaining acceptable comfort conditions.

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