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Technical Paper

Optimal Feedback Control with in-Cylinder Pressure Sensor under Engine Start Conditions

2011-04-12
2011-01-1422
In-cylinder pressure sensor, which provides the means for precise combustion control to achieve improved fuel economy, lower emissions, higher comfort, additional diagnostic functions etc., is becoming a necessity in future diesel engines, especially for chemical-kinetics dominated PCCI (Premixed Charge Compression Ignition) or LTC (Low Temperature Combustion) engines. In this paper, new control strategy is investigated to utilize in-cylinder pressure information into engine start process, in order to guarantee the success of engine start and in the meantime prevent penalty of fuel economy or pollutant emissions due to excessive fuel injection. An engine start acceleration model is established to analyze the engine start process. “In-cylinder Combustion Analysis Tool” (i-CAT), is used to acquire and process the in-cylinder pressure data and deliver the combustion indices to ECU (Engine Control Unit). Feedback control is accomplished in ECU based on this information.
Journal Article

Development of an On-Board PM Sensor for the OBD System Based on an Electrochemical Polarization

2011-08-30
2011-01-2059
An on-board particulate matter (PM) sensor, consisting of a gas-permeable electrochemical cell with a porous yttria-stabilized zirconia solid oxide electrolyte, was developed to assist the on-board diagnostics (OBD) system of a vehicle. Exhaust is pumped from the anode side to the cathode side and PM deposited on the anode is instantly oxidized by the catalytic effects of the metal component of the electrode at temperatures higher than 350°C. The PM oxidation reaction occurs at the three-phase boundary between the anode, electrolyte and gas phase, and causes a slight change in the bulk average oxygen concentration, which produces electrochemical polarization by the difference in oxygen partial pressures between the anode and cathode. The developed PM sensor has a detection limit of 2 mg/m₃, at which level will enable PM detection in the OBD system according to the EURO VI regulation.
Technical Paper

Analysis of In-cylinder Flow and Fuel Vapor Concentration Distribution in Gasoline Direct Injection Engine

2011-08-30
2011-01-2052
This paper details the air-fuel mixing process in a gasoline direct injection (DI) engine. Laser measurement techniques such as particle image velocimetry (PIV) and laser induced fluorescence (LIF) were employed on the optical engine with a transparent cylinder to analyze the in-cylinder flow and fuel vapor concentration. In addition, firing tests were conducted using an actual engine. Test results showed that the multi-stage injection is effective for air-fuel mixing and improvement of combustion stability.
Technical Paper

Development of In-cylinder Mixture and Flame Propagation Distribution Measurement Device with Spark Plug Type Sensor

2011-08-30
2011-01-2045
A new method to measure in-cylinder flame propagation and mixture distribution has been developed. The distribution is derived from analyzing the temporal history of flame spectra of CH* and C2*, which are detected by a spark plug type sensor with multi-optical fibers. The validity of this method was confirmed by verifying that the measurement results corresponded with the results of high speed flame visualization and laser induced fluorescence (LIF) measurement. This method was also applied to analysis of cyclic combustion fluctuation on start-up in a direct injection spark ignition (DISI) engine, and its applicability was confirmed.
Technical Paper

Morphology and Microstructure of Engine-Emitted Particulates

2009-06-15
2009-01-1906
The scattering properties (influenced by morphology) and refractive index (dependent on microstructure) of engine-emitted soot influences its effect on climate, as well as how we interpret optical measurements of aerosols. The morphology and microstructure of soot from two different engines were studied. The soot samples were collected from a 1.9L Volkswagen TDI engine for two different fuel types (ULSD and B20) and six speed/load combinations., as well as from a Cummins ISX heavy-duty engine using the Westport pilot-ignited high-pressure direct-injection (HPDI) natural-gas fuelling system for three different speed/load combinations. The transmission electron microscopy (TEM) was employed to investigate the soot morphology, emphasizing the fractal properties. Image processing was used to extract the geometrical properties of the thirty-five randomly chosen aggregates from each sample.
Technical Paper

Mixture Formation Process in a Spark-Ignition Engine with Ethanol Blended Gasoline

2009-06-15
2009-01-1957
In this study, fuel concentration measurements in a spark-ignition (SI) engine with ethanol blended gasoline were carried out using an optical sensor installed in the spark plug with laser infrared absorption technique. The spark plug sensor for in-situ fuel concentration measurement was applied to a port injected SI engine. The molar absorption coefficients of ethanol blended gasoline were determined for various pressures and temperatures in advance using a constant volume vessel with electric heating system. Ethanol blended gasoline with high volumetric ratios shows lower molar absorption coefficients due to lower molar absorption coefficients of ethanol. The molar absorption coefficients of ethanol blended gasoline can be estimated by considering the molar fraction of each component.
Technical Paper

A New Method to Convert Crankshaft Position Sensor (CPS) Signals into Angular Acceleration for Engine Combustion Evaluation

2009-05-19
2009-01-2052
With ever-increasing oil and gasoline prices, automotive manufacturers are striving to improve fuel economy. There are many factors that affect vehicle fuel consumption, such as engine size, vehicle weight, driving habits, and more. For a particular vehicle, engine combustion quality is one of the most important factors that affect fuel economy. Engine combustion quality also directly affects engine emissions, vehicle drivability, and vehicle NVH. Automotive manufacturers have been using different technologies to control engine combustion quality, such as using low cost pressure transducers to measure and control engine combustion in real time. In this paper, the authors have proposed a method that could directly use the Crank Position Sensor (CPS) signal to measure engine combustion quality.
Journal Article

Modeling and Experimental Investigation of Tire Cavity Noise Generation Mechanisms for a Rolling Tire

2009-05-19
2009-01-2104
Tire cavity noise refers to the excitation of the acoustic mode of a tire cavity. The noise exhibits itself as sharp resonance-like peaks with frequencies typically in the range of 190-250Hz. For a rolling tire, the tire contact with the road moves relative to the tire. Furthermore, the load on the tire breaks the circular symmetry of the tire. Consequently, the peak frequency of the cavity noise shows dependence on the tire load and the vehicle speed. There are no models that simultaneously take these two factors into consideration. In this paper, we propose an analytical model and present experimental verifications of predictions on the noise peak frequency and its dependence on the tire load and vehicle speed. A wireless experimental measurement system is also presented which enables the measurement of tire cavity frequency for both non-rolling and rolling conditions.
Technical Paper

Flexible-Fuel System for Small Motorcycles

2009-11-03
2009-32-0044
A flexible-fuel system for small motorcycles has been developed that can utilize both gasoline, and ethanol as an alternative to fossil fuel. For practicality, we aimed to develop a system that uses a minimum of additional parts. As a method to make both ethanol and gasoline available with the system, a control algorithm that estimates the ethanol concentration by utilizing the output voltage of an OXYGEN SENSOR and selects the appropriate injection quantity is employed. Usually, in automotive flexible-fuel vehicles (FFV), sub-tanks are mounted to ensure engine startability in cold temperatures. However, in small motorcycles, limitations of mounting space must be addressed. In this system, by clarifying the control logic and determining the difficult cases for cold temperature starts due to high ethanol concentration, configuring the indicator to promote gasoline mixture when the start is difficult enabled the elimination of the sub-tanks.
Technical Paper

An integrated approach to extract basic Suspension Data through Integration of tri-axial spindle coupled road simulator, wheel force transducer and a wheel vector sensor.

2009-12-13
2009-28-0027
In a highly competitive global as well as the domestic market of the passenger car industry, the search for the complete car is on the forefront. With such a situation, carmakers are experimenting with innovative technology on various development programs to cater the needs of the customer. This paper shows one such experimentation to extract the basic suspension Kinematics & Compliance data with the integration of a Tri-axial Spindle Coupled road load simulator, a wheel force transducer and a Wheel Vector Sensor in absence of expensive Suspension Parameters Measuring Machine (SPMM).
Technical Paper

Control System Development for Retrofit Automated Manual Transmissions

2009-12-13
2009-28-0001
For transmission suppliers tooled primarily for producing manual transmissions, retrofitting a manual transmission with actuators and a controller is business viable. It offers a low cost convenience for the consumer without losing fuel economy when compared to torque converter type automatics. For heavy duty truck fleets even the estimated 3% gain in fuel economy that the Automated Manual Transmission (AMT) offers over the manual transmission can result in lower operational costs. This paper provides a case study using a light duty transmission retrofitted with electric actuation for gears and the clutch. A high level description of the control algorithms and hardware is included. Clutch control is the most significant component of the AMT controller and it is addressed in detail during operations such as vehicle launch from rest, launch from coast and launch on grades.
Journal Article

Pressure Based Sensing Approach for Front Impacts

2011-04-12
2011-01-1443
This study demonstrates the use of pressure sensing technology to predict the crash severity of frontal impacts. It presents an investigation of the pressure change in the front structural elements (bumper, crush cans, rails) during crash events. A series of subsystem tests were conducted in the laboratory that represent a typical frontal crash development series and provided empirical data to support the analysis of the concept. The pressure signal energy at different sensor mounting locations was studied and design concepts were developed for amplifying the pressure signal. In addition, a pressure signal processing methodology was developed that relies on the analysis of the air flow behavior by normalizing and integrating the pressure changes. The processed signal from the pressure sensor is combined with the restraint control module (RCM) signals to define the crash severity, discriminate between the frontal crash modes and deploy the required restraint devices.
Technical Paper

Development of Sensor Attachment Criteria (Immunity) - Side Impact Sensor Mounted on Door Impact Beam

2011-04-12
2011-01-1445
The sensor mounted on the door impact beam plays a major role in side impact events. The accelerations of side impact sensors are processed by sensing algorithms to make a decision on the air bag deployment. The sensing signal criterion for the deployable condition is a well understood process. However, the non-deployment sensing signal for the immunity to abuse conditions is a function of sensor attachment stiffness to the base structure. The base structure can be a door inner panel or door impact beam. In one of the production program, the acceleration based sensor attached to the impact beam showed immunity issues in the abusive door slams/opening to objects. Hence, the computer Aided Engineering (CAE) analysis was used to develop the sensor attachment criterion.
Journal Article

Design of Engine-Out Virtual NOx Sensor Using Neural Networks and Dynamic System Identification

2011-04-12
2011-01-0694
Fuel economy improvement and stringent emission regulations worldwide require advanced air charging and combustion technologies, such as low temperature combustion, PCCI or HCCI combustion. Furthermore, NOx aftertreatment systems, like Selective Catalyst Reduction (SCR) or lean NOx trap (LNT), are needed to reduce vehicle tailpipe emissions. The information on engine-out NOx emissions is essential for engine combustion optimization, for engine and aftertreatment system development, especially for those involving combustion optimization, system integration, control strategies, and for on-board diagnosis (OBD). A physical NOx sensor involves additional cost and requires on-board diagnostic algorithms to monitor the performance of the NOx sensor.
Journal Article

Statistically Precise and Energy Efficient Accelerated Life Testing

2011-04-12
2011-01-0797
The basic idea of accelerated life testing (ALT) is to expose test units of a product to harsher-than-normal operating conditions to expedite failures so that the failure time distribution of the product and the associated life-stress relationship can be determined in a short time period. However, ALT often consumes significant amounts of energy. To avoid waste of energy in a wide spectrum of product development processes, we explore a new experimental design methodology that improves the reliability estimation precision of an ALT experiment while minimizing the total energy consumption of the experiment. The resulting optimally designed ALT experiment depends not only on the reliability of the product to be tested but also on the characteristics of the test equipment and the capability of its controller. A numerical example is provided to demonstrate the use of the methodology in practice.
Technical Paper

Rotor Position Sensor for Hybrid Drives and Electric Drives New Generation Eddy Current Position Sensor

2011-04-12
2011-01-0441
Electrification of the power train will play a key role in the struggle for higher energy efficiencies and reduced emissions of vehicles. Optimized control of modern electric motors requires precise measurement of the rotor position. In most industrial applications optoelectronic or magnetic incremental sensors or inductive resolves are used for the position measurement. Deploying electric drives in cars, however, adds additional requirements concerning robustness, manufacturing costs, integration and operating safety which are difficult to satisfy with traditional sensor technology. The drawbacks of current sensor technologies like high costs or sensibility to EMI will not be acceptable any more when electric power trains go into mass production. Electricfil has developed an Electric Motor Position Sensor (EMPOS) that provides a number of advantages over traditional sensors, including very high robustness to mechanical tolerances, a digital interface and low production costs [1].
Technical Paper

Relative Torque Estimation on Transmission Output Shaft with Speed Sensors

2011-04-12
2011-01-0392
Automobile drivers/passengers perceive automatic transmission (AT) shift quality through the torque transferred by transmission output shaft, so that torque regulation is critical in transmission shift control and etc. However, since a physical torque sensor is expensive, current shift control in AT is usually achieved by tracking a turbine speed profile due to the lack of the transmission output torque information. A direct torque feedback has long been desired for transmission shift control enhancement. This paper addresses a “virtual” torque sensor (VTS) algorithm that can provide an accurate estimate on the torque variation in the vehicle transmission output shaft using (existing) speed sensors. We have developed the algorithm using both the transmission output speed sensor and anti-lock braking system speed sensors. Practical solutions are provided to enhance the accuracy of the algorithm. The algorithm has been successfully implemented on both FWD and RWD vehicles.
Technical Paper

Comparison of an On-Board, Real-Time Electronic PM Sensor with Laboratory Instruments Using a 2009 Heavy-Duty Diesel Vehicle

2011-04-12
2011-01-0627
EmiSense Technologies, LLC (www.emisense.com) is commercializing its electronic particulate matter (PM) sensor that is based on technology developed at the University of Texas at Austin (UT). To demonstrate the capability of this sensor for real-time PM measurements and on board diagnostics (OBD) for failure detection of diesel particle filters (DPF), independent measurements were performed to characterize the engine PM emissions and to compare with the PM sensor response. Computational fluid dynamics (CFD) modeling was performed to characterize the hydrodynamics of the sensor's housing and to develop an improved PM sensor housing with reproducible hydrodynamics and an internal baffle to minimize orientation effects. PM sensors with the improved housing were evaluated in the truck exhaust of a heavy duty (HD) diesel engine tested on-road and on a chassis dynamometer at the University of California, Riverside (UCR) using their Mobile Emissions Laboratory (MEL).
Technical Paper

Exhaust Particle Sensor for OBD Application

2011-04-12
2011-01-0626
Efforts to develop a sensor for on-board diagnostics (OBD) of diesel vehicles are intensive as diesel particulate filters (DPFs) have become widespread around the world. This study presents a novel sensor that has been successfully tested for OBD diagnosis of damaged DPFs. The sensor is based on the "escaping current" technique. Based on this, a sample of exhaust gas is charged by a corona-ionized flow and is pumped by an ejector dilutor built in the sensor's construction. While the majority of ions return to the grounded sensor's body, a small quantity is lost with the charged particles exiting the sensor. This "escaping current" is a measurement of the particle concentration in the exhaust gas. Such a sensor has been developed and tested in real-exhaust of a diesel car and a diesel engine. The sensor provides high resolution (1 Hz, 0.3 s response time) and high sensitivity superseding OBD requirements. The sensor was used on an engine to monitor the efficiency of damaged DPFs.
Journal Article

Cylinder Head Gasket with Integrated Combustion Pressure Sensors for Advanced Engine Controls

2011-04-12
2011-01-0938
The cylinder head gasket with integrated combustion pressure sensors (CHGICPS) reported here targets advanced engine controls and in particular those based on the HCCI, PCCI, or LTC combustion principles, for gasoline, diesel, and alternative fuel engines. Due to the fiber optic combustion pressure sensor's (CPS) accuracy at low pressure during compression integrated into the CHGICPS, this device aims at in-cylinder prediction of mass air flow as well as in-cycle closed loop control of pilot fuel injection in a diesel engine. This paper reports on a replaceable CPS which allows installation and removal from the cylinder head gasket (CHG) without the need for removing the engine head. At the same time the distance layer thickness of CHGICPS is minimized to 2.5 mm and 3.4 mm, depending on the access ability and space constraints around coolant and lubrication ports in the engine.
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