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Technical Paper

Can Infotronics Enable Competitiveness of Electric Drive Vehicles?

1998-10-19
98C055
The hybrid electric vehicle (HEV) is already available commercially and is demonstrating the very significant benefit of improved fuel consumption. The costs associated with the hybrid vehicle are still high, and for novel types of auxiliary power unit are still undefined. Measures to improve the performance of HEV technology are emerging and include the traffic and navigation information which forms part of the telematics infrastructure. One of the key issues in enhancing HEV performance is journey prediction. Journey time and energy requirements can be products of a telematics system but form the basis for a significant performance enhancement to an HEV.
Technical Paper

Real-time Adaptive Predictive Control of the Diesel Engine Air-path Based on Fuzzy Parameters Estimation

2007-04-16
2007-01-0971
In this paper, a robust adaptive optimal tracking control design for the air-path system of diesel engines with uncertain parameters and external driver commands is proposed. First, an optimal controller based on the analytic solution of a performance index is derived. It achieves tracking of suitable references (corresponding to low emissions and fuel consumption) for both the air-fuel ratio and the fraction of the recirculated exhaust gas. Then, a fuzzy estimation algorithm is used to identify the plant parameters and consequently to adapt the controller online. The simulated diesel engine is a medium duty Caterpillar 3126B with six cylinders, equipped with a variable geometry turbocharger and an exhaust gas recirculation valve. The proposed controller design is based on the reduced third order mean value model and implemented as a closed-form nonlinear model predictive control law on the full order model.
Technical Paper

The Potential for Thermo-Electric Regeneration of Energy in Vehicles

2009-04-20
2009-01-1333
The pursuit of improved fuel economy is becoming an increasingly important objective for automotive manufacturers. The field of thermo-electrics is highlighted as a promising technology. The figure of merit, Z is the primary measure of the effectiveness of a thermo-electric material, and the values now being offered by researchers have reached the level where new applications become attractive. It is feasible to consider such modules incorporated into a thermoelectric generator to recover waste heat from exhaust gas flow – an available energy stream that has traditionally been neglected as unusable. As a precursor to a costly experimental study it is desirable to accurately simulate the application of a thermo-electric system to a vehicle exhaust to understand both the feasibility and potential drawbacks.
Technical Paper

In-Cylinder Pressure Modelling with Artificial Neural Networks

2011-04-12
2011-01-1417
More and more stringent emission regulations require advanced control technologies for combustion engines. This goes along with increased monitoring requirements of engine behaviour. In case of emissions behaviour and fuel consumption the actual combustion efficiency is of highest interest. A key parameter of combustion conditions is the in-cylinder pressure during engine cycle. The measurement and detection is difficult and cost intensive. Hence, modelling of in-cylinder conditions is a promising approach for finding optimum control behaviour. However, on-line controller design requires real-time scenarios which are difficult to model and current modelling approaches are either time consuming or inaccurate. This paper presents a new approach of in-cylinder condition prediction. Rather than reconstructing in-cylinder pressure signals from vibration transferred signals through cylinder heads or rods this approach predicts the conditions.
Technical Paper

Modeling Techniques to Support Fuel Path Control in Medium Duty Diesel Engines

2010-04-12
2010-01-0332
In modern production diesel engine control systems, fuel path control is still largely conducted through a system of tables that set mode, timing and injection quantity and with common rail systems, rail pressure. In the hands of an experienced team, such systems have proved so far able to meet emissions standards, but they lack the analytical underpinning that lead to systematic solutions. In high degree of freedom systems typified by modern fuel injection, there is substantial scope to deploy optimising closed loop strategies during calibration and potentially in the delivered product. In an optimising controller, a digital algorithm will explicitly trade-off conflicting objectives and follow trajectories during transients that continue to meet a defined set of criteria. Such an optimising controller must be based on a model of the system behaviour which is used in real time to investigate the consequences of proposed control actions.
Technical Paper

Modelling the Exhaust Gas Recirculation Mass Flow Rate in Modern Diesel Engines

2016-04-05
2016-01-0550
The intrinsic model accuracy limit of a commonly used Exhaust Gas Recirculation (EGR) mass flow rate model in diesel engine air path control is discussed in this paper. This EGR mass flow rate model is based on the flow of a compressible ideal gas with unchanged specific heat ratio through a restriction cross-area within a duct. A practical identification procedure of the model parameters is proposed based on the analysis of the engine data and model structure. This procedure has several advantages which include simplicity, low computation burden and low engine test cost. It is shown that model tuning requires only an EGR valve sweep test at a few engine steady state operating points.
Technical Paper

The Potential of Thermoelectric Generator in Parallel Hybrid Vehicle Applications

2017-03-28
2017-01-0189
This paper reports on an investigation into the potential for a thermoelectric generator (TEG) to improve the fuel economy of a mild hybrid vehicle. A simulation model of a parallel hybrid vehicle equipped with a TEG in the exhaust system is presented. This model is made up by three sub-models: a parallel hybrid vehicle model, an exhaust model and a TEG model. The model is based on a quasi-static approach, which runs a fast and simple estimation of the fuel consumption and CO2 emissions. The model is validated against both experimental and published data. Using this model, the annual fuel saving, CO2 reduction and net present value (NPV) of the TEG’s life time fuel saving are all investigated. The model is also used as a flexible tool for analysis of the sensitivity of vehicle fuel consumption to the TEG design parameters. The analysis results give an effective basis for optimization of the TEG design.
Technical Paper

The Position Control of a Gasoline Engine during Shutdown

2017-03-28
2017-01-1630
Since the first stop-start system introduced in 1983, more and more vehicles have been equipped with this kind of automatic engine control system. Recently, it was found that there is strong correlation between engine resting position and the subsequent engine start time. The utilization of the synchronization time working from a required engine stop position prior the engine start request was shown to reduce start times. Hence the position control of an engine during shutdown becomes more significant. A naturally aspirated engine was modelled using the GT-Suite modelling environment to facilitate the development of position controllers using Simulink ®. The use of respectively the throttle and a belt mounted motor generator to provide a control input was considered. Proportional-Integral-Differential (PID), sliding mode and deadbeat control strategies were each used in this study.
Technical Paper

Heat Recovery and Bottoming Cycles for SI and CI Engines - A Perspective

2006-04-03
2006-01-0662
The pursuit of fuel economy is forcing technology change across the range of control and engine management technologies. Improved thermal management has been addressed in order to promote fast warm-up, improved exhaust gas after-treatment performance, and lower variance in combustion through a consistent and high cylinder head temperature. Temperature management of exhaust gas is of increasing interest because of the need to maintain efficiency in after-treatment devices. More effective temperature management places requirements on heat exchange systems, and offers the potential for bottoming and heat recovery cycles that use energy transferred from the exhaust stream. Turbo-compounding is already established in heavy duty engines, where a reduction in exhaust gas temperature is the consequence of an additional stage of expansion through an exhaust turbine. A new project in electric turbo-compounding offers flexibility in the control of energy extracted from the exhaust stream[1].
Technical Paper

Modeling and Control of Diesel Engines Equipped with a Two-Stage Turbo-System

2008-04-14
2008-01-1018
The two-stage turbocharging technique is an effective way to improve performance and reduce emissions in diesel engines. In this paper, we consider a diesel engine equipped with an exhaust gas recirculation (EGR) valve and two turbochargers in series. The low pressure turbine is of fixed geometry and the high pressure turbine is a variable geometry turbine (VGT). The control objective is to regulate air-to-fuel (AFR), EGR exhaust fraction and the power ratio of the two turbines by coordinated manipulation of the EGR and VGT actuators. Unlike engines with a single turbocharger, in two-staged turbocharged engines, regulation of the power ratio of the turbines is also needed in order to adequately define the equilibrium point of the engine airpath. First, a mean value engine model (MVEM) is proposed to physically describe the air path dynamics. With rich excitation of the controls in the MVEM, we identify several linear models for different areas of the engine speed-torque envelope.
Technical Paper

Energy Recovery Systems for Engines

2008-04-14
2008-01-0309
Energy recovery from IC engines has proved to be of considerable interest across the range of vehicle applications. The motivation is substantial fuel economy gain that can be achieved with a minimal affect on the “host” technology of the vehicle. This paper reviews the initial results of a research project whose objective has been to identify system concepts and control methods for thermal recovery techniques. A vapour power cycle is the means of energy transfer. The architecture of the system is considered along with support of the fuel economy claims with the results of some hybrid vehicle modelling. An overview of the latest experimental equipment and design of the heat exchanger is presented. The choice of control architecture and strategy, whose goal is overall efficiency of the engine system, is presented and discussed. Some initial control results are presented.
Technical Paper

Life–Cycle Analysis and the Fuel Cell Car

2000-04-26
2000-01-1485
Many automotive manufacturers have announced their intention to launch fuel cell powered cars in the next few years. This has led to large research budgets aimed at new or emerging technologies. The emergence of a new automotive power and drive system allows a new beginning in designing the components of these systems with environmental impact in mind. That is, the whole car, from the ground up, can be built from “design for the environment” principles with an appreciation of “well to wheels” impact of its fuel. Using this approach, vehicles can be designed for minimum resource and energy use during manufacture and for low cost, low impact disassembly, leading not only to improved environmental performance but also to reduced manufacturing costs.
Technical Paper

The Controllability of Vapour Based Thermal Recovery Systems in Vehicles

2007-04-16
2007-01-0270
The idea of thermal energy recovery from vehicle engine exhaust flow is now well supported and funded. Through a number of research projects, several component technologies have been identified. Rankine cycle, turbo-compounding and thermo-electric systems have all attracted interest. Fuel economy improvements vary depending on the drive cycle and the capability of the underlying technologies, but have been reported as high as 25%. Our work at Sussex on a form of Rankine cycle has revealed generic issues about the control of thermal recovery and the associated modelling requirements. Typical issues include the balancing the rate of heat input to the recovery system with the loss of useful work from large temperature differences. The size of components dictates the control authority over the system and consequently its ability to follow changing conditions.
Technical Paper

Modeling and Control Design of a SOFC-IC Engine Hybrid System

2008-04-14
2008-01-0082
This paper presents a control system design strategy for a novel fuel cell - internal combustion engine hybrid power system. Dynamic control oriented models of the system components are developed. The transient behavior of the system components is investigated in order to determine control parameters and set-points. The analysis presented here is the first step towards development of a controller for this complex system. The results indicate various possibilities for control design and development. A control strategy is discussed to achieve system performance optimization.
Technical Paper

Improved Thermoelectric Generator Performance Using High Temperature Thermoelectric Materials

2017-03-28
2017-01-0121
Thermoelectric generator (TEG) has received more and more attention in its application in the harvesting of waste thermal energy in automotive engines. Even though the commercial Bismuth Telluride thermoelectric material only have 5% efficiency and 250°C hot side temperature limit, it is possible to generate peak 1kW electrical energy from a heavy-duty engine. If being equipped with 500W TEG, a passenger car has potential to save more than 2% fuel consumption and hence CO2 emission reduction. TEG has advantages of compact and motionless parts over other thermal harvest technologies such as Organic Rankine Cycle (ORC) and Turbo-Compound (TC). Intense research works are being carried on improving the thermal efficiency of the thermoelectric materials and increasing the hot side temperature limit. Future thermoelectric modules are expected to have 10% to 20% efficiency and over 500°C hot side temperature limit.
Journal Article

Accurate and Continuous Fuel Flow Rate Measurement Prediction for Real Time Application

2011-04-12
2011-01-1303
One of the most critical challenges currently facing the diesel engine industry is how to improve fuel economy under emission regulations. Improvement in fuel economy can be achieved by precisely controlling Air/Fuel ratio and by monitoring fuel consumption in real time. Accurate and repeatable measurements of fuel rate play a critical role in successfully controlling air/fuel ratio and in monitoring fuel consumption. Volumetric and gravimetric measurements are well-known methods for measuring fuel consumption of internal combustion engines. However, these methods are not suitable for obtaining fuel flow rate data used in real-time control/measurement. In this paper, neural networks are used to solve the problem concerning discontinuous data of fuel flow rate measured by using an AVL 733 s fuel meter. The continuous parts of discontinuous fuel flow rate are used to train and validate a neural network, which can then be used to predict the discontinuous parts of the fuel flow rate.
Journal Article

Evaluation of Spray/Wall Interaction Models under the Conditions Related to Diesel HCCI Engines

2008-06-23
2008-01-1632
Diesel homogeneous charge compression ignition (HCCI) engines with early injection can result in significant spray/wall impingement which seriously affects the fuel efficiency and emissions. In this paper, the spray/wall interaction models which are available in the literatures are reviewed, and the characteristics of modeling including spray impingement regime, splash threshold, mass fraction, size and velocity of the second droplets are summarized. Then three well developed spray/wall interaction models, O'Rourke and Amsden (OA) model, Bai and Gosman (BG) model and Han, Xu and Trigui (HXT) model, are implemented into KIVA-3V code, and validated by the experimental data from recent literatures under the conditions related to diesel HCCI engines. By comparing the spray pattern, droplet mass, size and velocity after the impingement, the thickness of the wall film and vapor distribution with the experimental data, the performance of these three models are evaluated.
Technical Paper

Modelling the Compression Ignition Engine for Control: Review and Future Trends.

2004-03-08
2004-01-0423
Constraints change as pollutant standards or embedded diagnosis demands require improvements in model accuracy and their suitability for control algorithm synthesis. From thermodynamic mathematical modelling to non-parametric models, a wide range of techniques has been investigated for the last thirty years involving both physicists and control engineers. The purpose of this paper is to give an overview of current modelling techniques oriented control analysis and design for compression ignition engines. Short examples illustrate each techniques and existing applications are considered. Comparison of various engine models exhibit the trend to include more physical knowledge inside model-based control design.
Technical Paper

Prediction of Gas Concentrations in a Three-Way Catalyst for On-Board Diagnostic Applications

2005-04-11
2005-01-0054
The process of controlling tailpipe emissions leads to the need to understand the dynamic behaviour of the after-treatment devices. The model provides the basis for design prediction, on-line diagnosis and real time control. Although a number of models have been presented in the literature, their efficient performance continues to require further development and validation to meet increasingly demanding requirements. Models have been developed that use the basic physical framework including thermal behaviour, fluid mechanics and basic chemistries. As more demands are placed on models, more phenomena need to be taken into account and in particular, progressively more of the chemistry of the Three-Way Catalyst (TWC) itself. In this paper we present a black-box model for a three-way catalytic converter that has been developed and tested using real experimental data.
Journal Article

Design and Optimisation of the Propulsion Control Strategy for a Pneumatic Hybrid City Bus

2016-04-05
2016-01-1175
A control strategy has been designed for a city bus equipped with a pneumatic hybrid propulsion system. The control system design is based on the precise management of energy flows during both energy storage and regeneration. Energy recovered from the braking process is stored in the form of compressed air that is redeployed for engine start and to supplement the engine air supply during vehicle acceleration. Operation modes are changed dynamically and the energy distribution is controlled to realize three principal functions: Stop-Start, Boost and Regenerative Braking. A forward facing simulation model facilitates an analysis of the vehicle dynamic performance, engine transient response, fuel economy and energy usage.
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