Application of a Wide Range Oxygen Sensor for the Misfire Detection

Misfiring in spark ignition engines should be avoided, otherwise unburned fuel and oxygen are brought into the catalyst, and subsequent combustion greatly increases the temperature, possibly resulting in immediate damage to the catalyst. As a new concept of misfire detection method, the signal fluctuation of a wide-range oxygen sensor has been introduced to monitor the fluctuation of the oxygen concentration at the exhaust manifold confluence point. The current research aims to develop a tool that is capable of predicting the variation in oxygen concentration at the exhaust manifold confluence point, and to investigate the flow characteristics of the misfired gas in the exhaust manifold under misfiring conditions in a cylinder. The oxygen concentration at the confluence point could be predicted by comparing the gas flowrate from the misfiring cylinder with the total exhaust gas flowrate. The gas flowrates from each of the cylinders were calculated using a one-dimensional engine cycle simulation including a gas dynamic model of the intake and exhaust systems. The variation in oxygen concentration was also determined experimentally using a fast-response hydrocarbon analyser. The trend of the oxygen concentration fluctuation calculated by the analytical model was compared with the experimental results. The analytical model could duplicate the measured trend of the fluctuation of oxygen concentration at the confluence point, which was characterized by twin peaks for one misfiring. The twin peaks are mainly caused by the mixing of the misfired gas with the burned gas from normally operating cylinders. The effects of engine load and speed on the characteristics of the variation in oxygen concentration were also investigated analytically and experimentally.

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Study of Air-Fuel Ratio Analyzer Based on CAN Bus

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.44-47.946 ◽

2010 ◽

Vol 44-47 ◽

pp. 946-950

Author(s):

Wei Bin Wu ◽

Tian Sheng Hong ◽

Jin Xing Guo ◽

Xian Mao Liu ◽

Xie Ming Guo ◽

...

Keyword(s):

Oxygen Sensor ◽

Can Bus ◽

Control Area ◽

Sensor Calibration ◽

Area Network ◽

Maximum Relative Error ◽

Calibration Laboratory ◽

Developed Country ◽

Fuel Ratio ◽

Wide Range

Air-Fuel Radio (AFR) analyzer technology is basically mastered by monopolies of developed country nowadays. Due to the lack of development in China, it has a strong practical value to study the accurate, rapid response and portable air-fuel ratio analyzer. This article is based on the AFR calculation model microcomputer hardware and software system design, background monitoring software design and debugging and measurement system, and on the choice of universal oxygen sensor calibration laboratory, establishing a wide-range of oxygen sensor output voltage and AFR model. The main features of AFR analyzer are measurement and display of air-fuel ratio, excess air coefficient or oxygen content, via RS232 communication with host computer or via Control Area Network (CAN) bus and vehicle ECU communication function. Test results showed that the error can be controlled at ± 0.03 λ range when comparing the Analyzer measurement values to calculated values. Compared with American Innovate company LM-2 air-fuel ratio analyser, the maximum relative error measured is ±0.08 when exhaust flood or too dilute, the average measurement error is ±0.04 while λ is between 0.8 and 1.3.

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Oxygen-generated spatial distribution of cell population links to p53 status

10.1101/2019.12.27.889394 ◽

2019 ◽

Author(s):

Shashank Taxak ◽

Uttam Pati

Keyword(s):

Spatial Distribution ◽

Cell Fate ◽

Cell Population ◽

Oxygen Sensor ◽

Dynamic State ◽

Specific Cell ◽

Wild Type ◽

Cell Fate Decisions ◽

Wide Range ◽

Wild Type P53

ABSTRACTLow oxygen induces wild type p53 inactivation and selects for mutant-like p53 phenotypes for aggressive tumor growth. Recently, we have shown wild type p53 as a cellular oxygen-sensor that operates in switch-like fashion to transform its characters of a tumor suppressor or promoter in a gradient of hypoxia. However, it is unclear how hypoxic tumors select for wild type p53 phenotypes for oxygen-sensitive responses. Here, we show that oxygen-generated spatial distribution of the cell population induces p53 phenotype-specific survival or death. We have found that a dynamic state of spatial scatters or clustering patterns of cell populations favor the survival of wild type more than the mutant phenotypes in a wide range of oxygen fluctuation by affecting p53 subcellular localization. Our results demonstrate how spatial distribution could function to establish wild type p53-mediated oxygen sensing and cell fate decisions in a cell population with heterogeneous p53 allele status. We anticipate that such behavior of cells in a gradient of oxygen can be utilized by the hypoxic tumors to maintain distinct p53 alleles and determine the release and metastasis of single or clustered circulating tumor cells (CTCs).Summary sentenceOxygen variation results in p53 phenotype-specific cell fate via the spatial distribution pattern of the cell population

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Estimation of Individual Cylinder Fuel Air Ratios from a Switching or Wide Range Oxygen Sensor for Engine Control and On-Board Diagnosis

SAE International Journal of Engines ◽

10.4271/2011-01-0710 ◽

2011 ◽

Vol 4 (1) ◽

pp. 813-827 ◽

Cited By ~ 6

Author(s):

Zhijian James Wu ◽

Bryon Wasacz

Keyword(s):

Oxygen Sensor ◽

Engine Control ◽

Wide Range

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A New Physics-Based Misfire Detection Technique for a SI Engine

Volume 1: Large Bore Engines; Advanced Combustion; Emissions Control Systems; Instrumentation, Controls, and Hybrids ◽

10.1115/icef2013-19096 ◽

2013 ◽

Cited By ~ 1

Author(s):

M. Boudaghi Kh. N. ◽

M. Shahbakhti ◽

S. A. Jazayeri

Keyword(s):

Steady State ◽

Engine Speed ◽

New Physics ◽

New Technique ◽

Si Engine ◽

Engine Model ◽

Compensation Factor ◽

Wide Range ◽

Percent Accuracy ◽

Misfire Detection

Control and detection of misfire is an essential part of on-board diagnosis of modern SI engines. This study proposes a novel model-based technique for misfire detection of a multi-cylinder SI engine. The new technique uses a dynamic engine model to determine mean output power, which is then used to calculate a new parameter for misfire detection. The new parameter directly relates to combustion period and is sensitive to the engine speed fluctuations caused by misfire. The new technique only requires measured engine speed data and it is computationally viable for use in a typical ECU. The new technique is evaluated experimentally on a 4-cylinder 1.6-liter SI engine. Three types of misfires are studied including single, continues, and multiple events. The steady-state and transient experiments were done for a wide range of engine speeds and engine loads, using a vehicle chassis dynamometer and on-road vehicle testing. The validation results show the new technique is capable to detect all the three types of misfire with up to 97 percent accuracy during steady-state conditions. The new technique is augmented with a compensation factor to improve the accuracy of the technique for transient operations. The resulting technique is shown to be capable of detecting misfire during both transient and steady-state engine conditions.

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Misfire Detection of Spark Ignition Engines Using a New Technique Based on Mean Output Power

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4029914 ◽

2015 ◽

Vol 137 (9) ◽

Cited By ~ 5

Author(s):

M. Boudaghi ◽

M. Shahbakhti ◽

S. A. Jazayeri

Keyword(s):

Steady State ◽

Output Power ◽

Engine Speed ◽

Control Unit ◽

Spark Ignition ◽

New Technique ◽

Si Engine ◽

Engine Model ◽

Wide Range ◽

Misfire Detection

Control and detection of misfire are an essential part of on-board diagnosis (OBD) of modern spark ignition (SI) engines. This study proposes a novel model-based technique for misfire detection for a multicylinder SI engine. The new technique uses a dynamic engine model to determine mean output power, which is then used to calculate a new parameter for misfire detection. The new parameter directly relates to combustion period and is sensitive to engine speed fluctuations caused by misfire. The new technique requires only measured engine speed data and is computationally viable for use in a typical engine control unit (ECU). The new technique is evaluated experimentally on a four-cylinder 1.6-l SI engine. Three types of misfire are studied including single, continuous, and multiple-event. The steady-state and transient experiments were done for a wide range of engine speeds and engine loads, using a vehicle chassis dynamometer and on-road vehicle testing. The validation results show that the new technique is able to detect all three types of misfire with up to 94% accuracy during steady-state conditions. The new technique is augmented with a compensation factor to improve the accuracy of the technique for transient operations. The resulting technique is shown to be capable of detecting misfire during both transient and steady-state engine conditions.

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