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Learning Based Model Predictive Control of Combustion Timing in Multi-Cylinder Partially Premixed Combustion Engine

Lund University-Xiufei Li, Lianhao Yin, Per Tunestal, Rolf Johansson
  • Technical Paper
  • 2019-24-0016
Published 2019-09-09 by SAE International in United States
Partially Premixed Combustion (PPC) has shown to be a promising advanced combustion mode for future engines in terms of efficiency and emission levels. The combustion timing should be suitably phased to realize high efficiency. However, a simple constant model based predictive controller is not sufficient for controlling the combustion during transient operation. This article proposed one learning based model predictive control (LBMPC) approach to achieve controllability and feasibility. A learning model was developed to capture combustion variation. Since PPC engines could have unacceptably high pressure-rise rates at different operation points, triple injection is applied as a solvent, with the use of two pilot fuel injections. The LBMPC controller utilizes the main injection timing to manage the combustion timing. The cylinder pressure is used as the combustion feedback. The method is validated in a multi-cylinder heavy-duty PPC engine for transient control.
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Enabling Efficient Functional Safety Audits - The Missing Link between ISO 26262 and Automotive SPICE

Dyson Technology Ltd.-Ireri Ibarra
Volvo Group-Per Johannessen
Published 2019-04-02 by SAE International in United States
In the field of electric and electronic (E/E) design for the automotive industry, there are separate traditions related to functional safety and software quality assurance. Both relying on the evaluation of the processes used; Automotive SPICE provides detailed guidance on how to perform this evaluation whilst ISO 26262 does not and simply mention Automotive SPICE as one possible solution. ISO 26262 additionally requires for an evaluation of the functional safety achieved by the product and uses the process evaluation (or functional safety audit in ISO 26262 terms) to support the final functional safety assessment. The purpose is to evaluate the implementation of the necessary safety processes according to the claimed scope defined in the safety plan.Automotive SPICE does not make a distinction on whether the application of the software under evaluation is safety related or not. ISO 26262 requires formal functional safety audits as a minimum for the part of the life cycle activities related to elements having ASIL C and ASIL D requirementsIn this paper we show how the link between ISO 26262 and…
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Control-Oriented Modeling of Soot Emissions in Gasoline Partially Premixed Combustion with Pilot Injection

Dalian University of Technology-Tianhao Yang, Wuqiang Long
Lund University-Lianhao Yin, Gabriel Ingesson, Per Tunestal, Rolf Johansson
Published 2017-03-28 by SAE International in United States
In this paper, a control-oriented soot model was developed for real-time soot prediction and combustion condition optimization in a gasoline Partially Premixed Combustion (PPC) Engine. PPC is a promising combustion concept that achieves high efficiency, low soot and NOx emissions simultaneously. However, soot emissions were found to be significantly increased with high EGR and pilot injection, therefore a predictive soot model is needed for PPC engine control. The sensitivity of soot emissions to injection events and late-cycle heat release was investigated on a multi-cylinder heavy duty gasoline PPC engine, which indicated main impact factors during soot formation and oxidation processes. The Hiroyasu empirical model was modified according to the sensitivity results, which indicated main influences during soot formation and oxidation processes. By introducing additional compensation factors, this model can be used to predict soot emissions under pilot injection. Model parameters were identified using experimental data under a few representative operating points. In order to reduce the cycle-to-cycle variation resulting in the soot estimation noise, a combustion duration calculation method is proposed to estimate CA10 and…
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An Experimental Investigation of a Multi-Cylinder Engine with Gasoline-Like Fuel towards a High Engine Efficiency

Lund University-Lianhao Yin, Gabriel Ingesson, Per Tunestal, Rolf Johansson, Bengt Johansson
Published 2016-04-05 by SAE International in United States
Partially Premixed Combustion (PPC) is a promising combustion concept with high thermodynamic efficiency and low emission level, and also with minimal modification of standard engine hardware. To use PPC in a production oriented engine, the optimal intake charge conditions for PPC should be included in the analysis. The experiments in this paper investigated and confirmed that the optimal intake conditions of net indicated efficiency for PPC are EGR between 50% and 55% as possible and the lambda close to 1.4. Heat-transfer energy and exhaust gas waste-energy contribute to the majority of the energy loss in the engine. The low EGR region has high heat-transfer and low exhaust gas enthalpy-waste, while the high EGR region has low heat-transfer and high exhaust gas waste-enthalpy. The optimal EGR condition is around 50% where the smallest energy loss is found as a trade-off between heat transfer and exhaust-gas enthalpy-waste. Lambda close to 1.4 results from the trade-off of high gas-exchange efficiency with low lambda and high thermodynamic efficiency with high lambda. The optimal inlet charge condition was also applied…
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Evaluation of Nonlinear Estimation Methods for Calibration of a Heat-Release Model

SAE International Journal of Engines

Lund University, Dept Automatic Control-Gabriel Ingesson, Rolf Johansson
Lund University, Dept Energy Science-Lianhao Yin, Per Tunestal
  • Journal Article
  • 2016-01-0820
Published 2016-04-05 by SAE International in United States
Model-based analysis of in-cylinder pressure sensor signals has been a key component for internal combustion engine research, diagnostics and controller development during the past decades. This analysis is often based on simple thermodynamic models of the in-cylinder processes. In order for the analysis to give accurate results, the models need to be sufficiently calibrated. This paper investigates the use of the extended Kalman filter and the particle filter for the purpose of online estimation of top-dead-center offset, a convective heat-transfer coefficient and cylinder-wall temperature in a Gatowski heat-release model. Simulation results show that the filters are consistent in estimating the true parameters, that the assumed model uncertainty and heat-release noise density works as filter tuning parameters. The filters were found to be sensitive to errors on pressure-sensor offset and the cylinder compression ratio. The filters were also evaluated against experimental data and the result showed converge times of 200 engine cycles with acceptable steady-state variance for both filters.
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Simultaneous Control of Combustion Timing and Ignition Delay in Multi-Cylinder Partially Premixed Combustion

SAE International Journal of Engines

Lund University-Gabriel Ingesson, Lianhao Yin, Rolf Johansson, Per Tunestal
  • Journal Article
  • 2015-24-2424
Published 2015-09-06 by SAE International in United States
In low-temperature combustion concepts such as partially premixed combustion, the ignition delay should be large enough in order to ensure sufficient fuel and air mixing before the start of combustion. It is also necessary that the combustion timing is sufficiently well phased for high thermal efficiency.Since the ignition delay and combustion timing are intimately coupled, the decoupling of these two quantities gives rise to an interesting multiple input, multiple output control problem where the control of the air system and the fuel injection system have to be combined. In a multi-cylinder engine this problem becomes underdetermined or uncontrollable with more outputs than inputs.This article investigates model-based cycle-to-cycle cylinder-individual closed-loop control of the ignition delay and the combustion phasing in a multi-cylinder heavy-duty DI engine running on a gasoline fuel mixture. The controller design of choice was model predictive control (MPC) which is a suitable design for multiple input/output systems with actuator constraints. Ignition delay and combustion phasing were extracted from cooled in-cylinder pressure sensors and controlled by manipulating injection timings, the gas mixture temperature and…
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A Model-Based Injection-Timing Strategy for Combustion-Timing Control

SAE International Journal of Engines

Lund University-Gabriel Ingesson, Lianhao Yin, Rolf Johansson, Per Tunestal
  • Journal Article
  • 2015-01-0870
Published 2015-04-14 by SAE International in United States
The combustion timing in internal combustion engines affects the fuel consumption, in-cylinder peak pressure, engine noise and emission levels. The combination of an in-cylinder pressure sensor together with a direct injection fuel system lends itself well for cycle-to-cycle control of the combustion timing.This paper presents a method of controlling the combustion timing by the use of a cycle-to-cycle injection-timing algorithm. At each cycle the currently estimated heat-release rate is used to predict the in-cylinder pressure change due to a combustion-timing shift.The prediction is then used to obtain a cycle-to-cycle model that relates combustion timing to gross indicated mean effective pressure, max pressure and max pressure derivative. Then the injection timing that controls the combustion timing is decided by solving an optimization problem involving the model obtained.The controller was experimentally tested on a Scania D13 heavy-duty diesel engine in the lower load range with a fuel mixture of 80 volume % gasoline and 20 volume % n-heptane.Controller-performance test results are presented for different controller and model parameter settings at three different operating points. The results show…
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Sensitivity Analysis of Partially Premixed Combustion (PPC) for Control Purposes

Lund University-Lianhao Yin, Gabriel Ingesson, Sam Shamun, Per Tunestal, Rolf Johansson, Bengt Johansson
Published 2015-04-14 by SAE International in United States
Partially Premixed Combustion (PPC) is a promising advanced combustion mode for future engines. In order to investigate the sensitivity of PPC to exhaust gas recirculation (EGR) rate, intake gas temperature, intake gas pressure, and injection timing, these parameters were swept individually at three different loads in a single cylinder diesel engine with gasoline-like fuel.A factor of sensitivity was defined to indicate the combustion's controllability and sensitivity to inlet gas parameters and injection timings. Through analysis of experimental results, a control window of inlet gas parameters and injection timings is obtained at different loads in PPC mode from 5 bar to 10 bar IMEPg load at 1200 rpm.To further study the PPC controllability with injection timing, main injection timing was adjusted to sustain steady combustion phasing subject to perturbation of inlet gas state. Experimental results show that the main injection timing can resist the interference of intake parameters and maintain constant combustion phasing. Injection timing control is a promising approach to maintain high engine efficiency and low emission levels during transient operation.
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V2V Communication Quality: Measurements in a Cooperative Automotive Platooning Application

SAE International Journal of Passenger Cars - Electronic and Electrical Systems

Qamcom Research & Technology-Ali Tehrani
Qamcom Research and Technology AB-Carl Bergenhem
  • Journal Article
  • 2014-01-0302
Published 2014-04-01 by SAE International in United States
This paper presents measurements on Vehicle to Vehicle (V2V) communication between participants in a platooning application. Platooning, according to the SARTRE concept, implies several vehicles travelling together in tight formation, with a manually driven heavy lead vehicle. The platoon being studied consists of five vehicles; two trucks in the lead and three passenger cars. The V2V-communication node in each vehicle contains an 802.11p radio at 5,9 GHz. It is used to send messages between vehicles to coordinate movements and maintain safety in the platoon. Another cooperative application that relies on V2V-communication is multiple UAVs flying in formation; as investigated in KARYON. This project also investigates cooperative autonomous vehicles. In both applications, V2V-communication is an enabling technology. Two metrics are studied to quantify the V2V-communication quality: system packet error rate and consecutive packet loss. These two metrics characterize the communication quality in the different tests (speed, antenna position and two tracks). The paper draws general conclusions on the performance of V2V-communication. The presented test results supports comparison of the tested antenna placements on the trucks and…
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Functional Safety for Cooperative Systems

Qamcom-Carl Bergenhem
SP Technical Research Inst of Sweden-Josef Nilsson, Jan Jacobson, Rolf Johansson, Jonny Vinter
Published 2013-04-08 by SAE International in United States
This paper investigates what challenges arise when extending the scope of functional safety for road vehicles to also include cooperative systems. Two generic alternatives are presented and compared with one another. The first alternative is to use a vehicle centric perspective as is the case in the traditional interpretation of ISO 26262 today. Here, an “item” (the top level system or systems for which functional safety is to be assured) is assumed to be confined to one vehicle. In the vehicle centric perspective inter-vehicle communication is not an architectural element and is therefore not a candidate for redundancy as part of the functional safety concept. The second alternative is to regard a cooperative system from a cooperative perspective. This implies that one item may span over several vehicles. The choice of perspective has implications in several ways. We investigate the implications for the cooperative item and in what ways the results may differ when going through the reference life cycle of ISO 26262. In particular we look at classification of hazardous events where severity is…
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