Battery state of charge management strategies for a real-time controller of a Plug-in Hybrid Electric Vehicle

Abstract This paper deals with the development of energy management strategies for a hybrid electric vehicle (HEV), aiming to reduce the global energy consumption. The vehicle is a Plug-in HEV, and its model had been validated on New European Driving Cycle (NEDC). A real-time model-based supervisory controller is implemented, called Equivalent Consumption Minimization Strategy (ECMS), and it is compared with the original heuristic control. Three ways to manage the energy stored in the battery along the driving mission are presented. Predictive information is then introduced to increase vehicle driveability. Conclusions summarize the benefits of such approach, showing satisfactory results also considering the driver comfort

model based control of intake air temperature and humidity on the test bench

Abstract Engine test benches are crucial instruments to perform tests on internal combustion engines. Possible purposes of these tests are to detect the engine performance, check the reliability of the components or make a proper calibration of engine control systems managing the actuations. Since many factors affect tests results in terms of performance, emissions and components durability, an engine test bench is equipped with several conditioning systems (oil, water and air temperature, air humidity, etc.). One of the most important systems is the HVAC (Heating, Ventilating and Air Conditioning), that is essential to control the conditions of the intake air. Intake air temperature, pressure and humidity should be controllable test parameters, because they play a key role on the combustion development. In fact, they can heavily affect the performance detected, such as power and specific consumption, and, in some cases, they may promote knock occurrence. This work presents an HVAC model-based control methodology, where each component of the air treatment system (humidifier, pre-heating and post-heating resistors, chiller and fan) is managed coupling open-loop and closed-loop controls. Each branch of the control model is composed of two parts, the first one to evaluate the target for the given HVAC component, based on the system physical model, the second one is a PID controller based on the difference between the set-point and the feedback values. The control methodology has been validated on an engine test bench where the automation system has been developed on an open software Real-Time compatible platform, allowing the integration of the HVAC control with all other functionalities concerning the test management. The paper shows the plant layout, details the control strategy and finally analyzes experimental results obtained on the test bench, highlighting the benefits of the proposed HVAC management approach

Analysis of Pre-ignition Combustions Triggered by Heavy Knocking Events in a Turbocharged GDI Engine

Abstract In this paper, a pre-ignition sequence with detrimental effects on the engine has been analysed and described, with the aim of identifying the main parameters involved in damaging the combustion chamber components. The experiment was carried out in a wider research context, focused on knock damage mechanisms in turbocharged GDI engines. The pre-ignition sequence was a consequence of a high knock condition, induced at high load at 4500 rpm. The abnormal thermal load due to knock caused overheating of the whole combustion chamber, until the spark plug electrodes became a "hot spot", resulting in premature flame initiation in the following cycles, with a self-sustaining mechanism. Slight cylindrical differences, mainly in terms of volumetric efficiency, allowed comparisons and correlations between indicated parameters, pre-ignition sequence and damage. The main responsible in damaging the engine, in this case and for this engine, is the extremely high heat transferred to the walls in the pre-ignited cycles, characterized by higher mean temperatures. Heavy knock triggered the pre-ignited combustions but progressively reduced its intensity as the spontaneous ignition advance increased, thus having a secondary role in damaging directly the combustion chamber

Combustion and Intake/Exhaust Systems Diagnosis Based on Acoustic Emissions of a GDI TC Engine

Abstract Due to increasingly stringent emission regulations and the need for more efficient powertrains, engine control systems that have been developed during the recent years have become more and more sophisticated. Obtaining accurate information about the combustion process and about all the subsystems that compose the engine can be considered key to reach the maximum overall performance. Low-cost in-cylinder pressure and turbo speed sensors are being developed, but they still present long-term reliability issues, and represent a considerable part of the entire engine management system cost. Sound emissions represent an extremely rich information source about the operating conditions of all the subsystems that comprise the entire engine. The paper shows how it is possible to extract fundamental information regarding the combustion process (such as knock and misfire), turbo speed, and air path fault at the same time, by performing an appropriate analysis of the engine acoustic emissions acquired from the very same microphone, which can thus be considered as an innovative, multifunction, and low-cost sensor for automotive applications

Accelerometer Based Methodology for Combustion Parameters Estimation

Due to increasingly stringent emission regulations and the need of more efficient powertrains, obtaining information about combustion process becomes a key factor. Low-cost in-cylinder pressure sensors are being developed, but they still present longterm reliability issues, and represent a considerable part of the engine management system cost. Research is being conducted in order to develop methodologies for extracting relevant combustion information using standard sensors already installed on-board. The present work introduces a methodology for combustion parameters estimation, through a control-oriented analysis of structureborne sound. The paper also shows experimental results obtained applying the estimation methodology to different passenger car engines. © 2015 The Authors. Published by Elsevier Ltd

Transient Spark Advance Calibration Approach

Combustion control is assuming a crucial role in reducing engine tailpipe emissions while maximizing performance. The effort in the calibration of control parameters affecting the combustion development can be very demanding. One of the most effective factors influencing performance and efficiency is the combustion phasing: in Spark Ignition (SI) engines it is affected by factors such as Spark Advance (SA), Air-Fuel Ratio (AFR), Exhaust Gas Recirculation (EGR), Variable Valve Timing (VVT). SA optimal values are usually determined by means of calibration procedures carried out in steady state conditions on the test bench by changing SA values while monitoring performance indicators, such as Brake and Indicated Mean Effective Pressure (BMEP, IMEP), Brake Specific Fuel Consumption (BSFC) and pollutant emissions. The effect of SA on combustion is stochastic, due to the cycle-to-cycle variation: the analysis of mean values requires many engine cycles to be significant of the performance obtained with the given control setting. Moreover, often the effect of SA on engine performance must be investigated for different settings of other control parameters (EGR, VVT, AFR). The calibration process is time consuming involving exhaustive tests followed by off-line data analysis. This paper presents the application of a dynamic calibration methodology, with the objective of reducing the calibration duration. The proposed approach is based on transient tests, coupled with a statistical investigation, allowing reliable performance analysis even with a low number of engine cycles. The methodology has been developed and tested off-line, then it has been implemented in Real-Time. The combustion analysis system has been integrated with the ECU management software and the test bench controller, in order to perform a fully automatic calibration. © 2013 The Authors