Abstract: A catalyst having an oxygen storage capacity is provided in an exhaust passage of an internal combustion engine. A catalyst temperature calculating device calculates an oxygen storage amount of the catalyst to a value greater than or equal to zero and less than or equal to than a maximum value based on an amount of oxygen and an amount of unburned fuel components in a fluid flowing into the catalyst. A temperature calculation process calculates a temperature of the catalyst assuming that an amount of temperature rise of the catalyst is larger when an increase amount of the oxygen storage amount is large than when the increase amount of the oxygen storage amount is small in a case where the oxygen storage amount increases.

Abstract: A catalyst deterioration diagnosis device includes: a unit configured to obtain a temperature of a catalyst; a unit configured to obtain a sensor output from a gas sensor disposed between the catalyst and an exhaust port; and a unit configured to determine the catalyst to be faulty when the temperature of the catalyst obtained when the sensor output becomes a preset evaluative output is equal to or higher than an evaluative catalyst temperature.

Abstract: A selective catalytic reduction system control system (10) and method of its use include an ammonia (“NH3”) slip sensor (13) located within an interior space (27) of an exhaust stack (15) of a selective catalytic reactor (31), toward an inlet end (25) of the stack (15); a housing (17) located within the interior space of the exhaust stack; the housing including face panels 19; a nitrogen oxides (“NOx”) sensor (11) contained within an interior space (29) defined by the face panels of the housing, at least two of the face panels (19I, 19O) containing an oxidation catalyst; and a dosing controller (59) in communication with the NH3 and NOx sensors, the dosing controller including a microprocessor with dosing logic embedded thereon. The housing with oxidation catalyst acts as a linear box, isolating the NOx sensor from NH3 slip, linearizing the NOx sensor signal.

Abstract: The invention relates to a diagnostic method for checking the functionality of a component for the exhaust-gas aftertreatment of an internal combustion engine. For this purpose, in an internal combustion engine, a secondary air supply is provided by means of which an excess of oxygen can be generated in the exhaust gas channel essentially independently of the operating conditions of the internal combustion engine, and wherein said excess of oxygen is utilized for the measurement of an oxygen storage capacity of the component or of a signal change at the component. It is provided that the component is subsequently subjected to a substoichiometric exhaust gas in order that the oxygen release capacity or the signal change upon a change from superstoichiometric exhaust gas to a substoichiometric exhaust gas is also taken into consideration in the diagnosis. The invention also relates to a device for exhaust-gas aftertreatment, which is designed to be able to carry out a method of said type.

Abstract: A method configured to be executed by a system controller. The method includes obtaining a first metric from a first sensor installed in a first underground vault of a system of interconnected underground vaults, and obtaining a second metric from a second sensor installed in a second underground vault of the system. The first and second underground vaults are in fluid communication with one another via one or more connections. The method also includes locating a gas source based at least in part on one or both of the first and second metrics, and performing an action. The action includes identifying the gas source to one or more users and/or altering a rate of atmospheric turnover in at least a portion of the system.

Abstract: Methods, systems, and devices for managing motor torque smoothing for internal combustion engine cylinder recharging events are described herein. An engine controller in a vehicle for managing motor torque smoothing for internal combustion engine cylinder recharging events may be configured to operate the internal combustion engine at a firing fraction that is less than a value of 1.0, wherein one or more cylinders are not designated to be fired, determine a recharge event time period where a particular one of the cylinders that have not been designated to be fired is recharged, identify a disruption quantity of torque during the recharging event time period, and actuate an additional motor to initiate a supplemental quantity of torque during the recharge event time period based on the disruption quantity of torque.

Abstract: An exhaust system includes an exhaust duct having an internal surface defining an exhaust gas passage extending along an axis. At least one sensor opening is in the exhaust duct and is configured to receive an exhaust gas sensor. A wall is positioned within the exhaust gas passage to extend at least partially around the at least one sensor opening. The wall has an inner wall surface defining an internal volume. An inlet pipe ring is in fluid communication with the internal volume, and the inlet pipe ring extends from a first end open to the internal volume to a second end this is also in fluid communication with the internal volume. The inlet pipe ring includes a plurality of inlet apertures.

Abstract: An exhaust gas aftertreatment system for an internal combustion engine charged by an exhaust gas turbocharger and spark-ignited by means of spark plugs has a particulate filter and a first three-way catalytic converter downstream from the particulate filter in a position close to the engine in an exhaust gas system connected to an outlet of the internal combustion engine and another three-way catalytic converter arranged in the underbody position of the motor vehicle, downstream from the first three-way catalytic converter. An exhaust gas burner is active from the start of the engine, introducing hot exhaust gas into the exhaust gas system downstream from the particulate filter, in order to heat at least one of the three-way catalytic converts to a light-off temperature, as quickly as possible after the cold start, thereby allowing an efficient exhaust gas aftertreatment.

Abstract: An exhaust system for an internal combustion engine; the exhaust system comprises: at least one an exhaust duct, which originates from the internal combustion engine; at least one exhaust gas treatment device, which is arranged along the exhaust duct; and a silencing device, which is arranged along the exhaust duct downstream of the exhaust gas treatment device. The silencing device comprises a silencing valve, which intercepts the exhaust duct and is movable between a completely open position and a completely closed position. In the completely closed position, the silencing valve has a first free section for the passage of the exhaust gases having a first area other than zero, so that the exhaust gases can flow through the silencing valve even when the silencing valve is in the completely closed position.

Abstract: An engine and one or more aftertreatment subsystems integrated into one system for optimization and control. At least one controller may be connected to the engine and the one or more aftertreatment subsystems. The controller may contain and execute a program for the optimization and control of the one system. Controller may receive information pertinent to the engine and the one or more aftertreatment subsystems for the program. The controller may prescribe setpoints and constraints for measured variables and positions of actuators according to the program to aid in effecting the optimization and control of the one system.

Abstract: Methods and systems are provided for operating a split exhaust engine system that provides blowthrough air and exhaust gas recirculation to an intake passage via a first exhaust manifold and exhaust gas to an exhaust passage via a second exhaust manifold. In one example, a method may include supplying air to an exhaust system at a location downstream of an emissions control device via the first exhaust manifold, the air not having participated in combustion in the engine, the first exhaust manifold in fluidic communication with a first exhaust valve of a cylinder and an intake manifold, the cylinder including a second exhaust valve in fluidic communication with the second exhaust manifold. The method may further include adjusting an amount of fuel injected to the engine in response to output of a first oxygen sensor, the first oxygen sensor positioned in the exhaust system upstream of the emissions control device.

Abstract: An aftertreatment system comprises an aftertreatment component. An outlet sensor is positioned downstream of the aftertreatment component. A controller is communicatively coupled to the outlet sensor. The controller is configured to interpret an outlet signal from the outlet sensor. The outlet signal is indicative of a performance of the aftertreatment component. The controller determines if the aftertreatment component has deactivated. In response to determining that the aftertreatment component has deactivated, the controller provides a catalyst active material to at least a portion of the aftertreatment component. The catalyst active material coats at least the portion of the aftertreatment component so as to remanufacture the aftertreatment component.

Abstract: An exhaust purification system of an internal combustion engine includes a catalyst arranged in an exhaust passage of the internal combustion engine and able to store oxygen, a storage amount calculating part configured to calculate an oxygen storage amount of the catalyst, a poisoning amount calculating part configured to calculate a poisoning amount of the catalyst, and an oxygen amount control part configured to control an amount of oxygen supplied to the catalyst based on the oxygen storage amount and the poisoning amount.

Abstract: A method for controlling an air-fuel ratio based on an oxygen storage amount of a catalyst may include: performing, by a controller, a catalyst oxygen storage amount (OSA) feedback control for a rich control of the air-fuel ratio so that the oxygen storage amount of the catalyst is within a threshold value; and performing, by the controller, a target voltage feedback control for a lean or rich control of the air-fuel ratio so that an output voltage value of an oxygen sensor provided in the rear of the catalyst satisfies a target voltage value.

Abstract: An exhaust gas-purifying system includes an exhaust gas-purifying unit that includes one or more exhaust gas-purifying catalysts, is supplied with the exhaust gas from a combustion engine, and purifies the exhaust gas so that the exhaust gas can be released to the atmosphere, a sensor that detects a concentration of nitrogen oxides contained in the purified exhaust gas, and a processing section that makes a judgment with respect to at least one of the exhaust gas-purifying catalysts, as to whether or not a performance is maintained at a sufficient level, based on the concentration detected by the sensor.

Abstract: A system and method for determining an error in a vehicle catalytic converter prevent an incorrect determination and improve reliability of the determination. The method includes determining whether the error occurs in the catalytic converter in consideration of both fuel injection state and fuel injection cut-off state.

Abstract: A system and methods for a turbo-boost control system are disclosed for providing a driver of a vehicle with greater control over vehicle performance. The turbo-boost control system instructs an electronic control unit of the vehicle to increase the manifold pressure to a higher level before releasing the pressure through a waste gate so as to provide a greater power output of the engine. The turbo-boost control system includes a control module, a wiring harness, and a signal adjuster. The wiring harness couples the control module with a turbo inlet pressure sensor, a manifold absolute pressure sensor, and an electronic control unit of the vehicle. The control module sends signals to the electronic control unit based on input readings from the turbo inlet pressure sensor and the manifold absolute pressure sensor. The signal adjuster includes a rheostat that enables manual adjustment of the power output of the engine.

Abstract: A control device for the internal combustion engine is provided with a carbon dioxide concentration control part configured to cause a concentration of carbon dioxide in exhaust flowing into the filter to decrease when the temperature of the filter becomes a predetermined first temperature setting or more and less than a predetermined second temperature setting. The first temperature setting is made a temperature selected from a temperature band at which ash deposited on the filter can be made to be separate from the filter when the inside of the filter is in an atmosphere where the concentration of carbon dioxide is lower than when it is in an exhaust atmosphere. The second temperature setting is made a temperature set so as to prevent excessive temperature rise of the catalyst device.

Abstract: A method for determining a presence of a particle filter in the exhaust gas tract of a petrol-operated internal combustion engine comprises: determining a measured differential pressure curve from a first pressure curve measured in the exhaust gas tract using a first pressure sensor arranged upstream of an installation position of the particle filter, and a second pressure curve measured using a second pressure sensor arranged downstream of an installation position determining a first result curve with a first low-pass filtration of the measured differential pressure curve; determining a second result curve by means of a second low-pass filtration of the first result curve; determining a first differential result curve by forming the difference between the first result curve and the second result curve; determining a first amount result curve by forming the amount of the first differential result curve; determining an expected differential pressure curve.

Abstract: The invention relates to an exhaust aftertreatment system for an internal combustion engine that, at its outlet, is connected to an exhaust gas system. In the exhaust gas system, a three-way catalytic converter close to the engine, an electrically heatable three-way catalytic converter downstream from the three-way catalytic converter close to the engine, and further downstream, a particulate filter or a four-way catalytic converter are situated in the flow direction of an exhaust gas of the internal combustion engine through an exhaust duct of the exhaust gas system. In addition, the exhaust aftertreatment system includes a secondary air system with a secondary air pump and a secondary air line, which opens into the exhaust duct at an introduction point downstream from the three-way catalytic converter close to the engine and upstream from the electrically heatable three-way catalytic converter.

Abstract: A catalyst deterioration diagnosis system includes an air-fuel ratio detection element and a NOx detection element on a downstream side with respect to a catalyst, and a control element. The control element causes an engine to perform diagnosis operation performed with an exhaust gas temperature being kept at 600° C. or higher, such that at a timing when a downstream air-fuel ratio in a lean operation state reaches a threshold value, the engine is transitioned to a rich operation state, and at a timing that is a predetermined period after a downstream air-fuel ratio in a rich operation state reaches a threshold value, the engine is transitioned to a lean operation state. The diagnosis element compares NOx concentration during the rich operation state to a diagnosis threshold value, thereby to diagnose a degree of deterioration of NOx reduction capability of the catalyst.

Abstract: Diagnostics for inadequate performance and/or degradation of an exhaust aftertreatment system are disclosed. A performance degradation analysis of the exhaust aftertreatment system includes a determination of a long term brake specific NOx value over a time period and a comparison of the long term brake specific NOx value to a threshold value.

Abstract: Methods and apparatuses for calibration and control of various engine subsystems using a target value approach. Under the target value approach, the control of each engine subsystem is separated or decoupled to include a set of target values, or a reference value set. A subsystem has a corresponding target determiner, which provides a target value set, or reference value set, in response to a basis variable set and optionally an overall subsystem target. The basis variable set includes parameters selected to robustly characterize the variables that affect the operation of the particular subsystem. The target determiner is optionally calibrated to provide a reference value set within specifications of the subsystem. A physical subsystem controller operates in response to the reference value set.

Abstract: An exhaust aftertreatment system for an internal combustion engine has an exhaust system having at least one three-way catalyst near the engine, wherein a particulate filter is arranged downstream from the three-way catalyst, preferably in an underbody installation in a motor vehicle. A heated catalyst, which has at least one heating stage that can be heated by means of an electric heating element, is provided upstream from the at least one three-way catalyst and downstream from the particulate filter. The at least one electrically heatable heating stage is supplied with electric power directly from a generator that is operatively connected to the internal combustion engine, so that heating of the heated catalyst takes place essentially independently of the charge status of the vehicle battery.

Abstract: A fire detection system includes: a transmitter to output a first optical signal including a wavelength absorbed by a first gas generated in an early stage of a fire and a second optical signal including a wavelength absorbed by a second gas having an amount of generation being increased as the fire progresses; and a receiver including a detector to receive the first optical signal and the second optical signal propagating through a measuring target space, a first gas concentration calculator to calculate a concentration of the first gas, a second gas concentration calculator to calculate a concentration of the second gas, a smoke concentration calculator to calculate a smoke concentration, and a determination unit to determine progress of the fire, based on the concentration of the first gas, the concentration of the second gas, the smoke concentration, and an environmental temperature.

Abstract: A method for operating an exhaust gas recirculation system using rationality diagnostics for an automobile vehicle includes: estimating an oxygen storage content (OSC) of a catalytic converter of a vehicle; comparing an amount of oxygen stored in the catalytic converter to an OSC threshold; initiating a closed oxygen storage control (COSC) event for a predetermined one of multiple cylinders of an engine of a vehicle if the OSC threshold is met or exceeded, the COSC event targeting a rich air-fuel equivalence ratio (EQR) for the predetermined one of the multiple cylinders; and directing a fuel injector communicating with the predetermined one of the multiple cylinders to operate the predetermined one of the multiple cylinders at the rich EQR.

Abstract: A housing connection element (10) for a housing of an exhaust gas treatment assembly unit of an exhaust system, especially for an internal combustion engine, includes a first housing part (16) with an essentially cylindrical first connection area (18) for connection to a circumferential wall (14) of a housing (12) of an exhaust gas treatment assembly unit. A tapered area (20) is adjacent to the first connection area (18). An annular, second housing part (40) is connected to the tapered area (20). A second connection area (46) is provided for connection to an exhaust gas-carrying component of an exhaust system. At least one sensor sleeve (48, 50) is in a sleeve receiving area (24) of the first housing part (16). The sleeve receiving area (24) is formed in the tapered area (20).

Abstract: Methods and systems are provided for monitoring a NOx storage capacity of a passive NOx adsorption catalyst (PNA) included in an exhaust gas after-treatment system of an engine. In one example, a method may include, after an engine cold start and prior to an exhaust gas temperature reaching an upper threshold temperature, indicating degradation of the PNA based on an amount of NOx measured downstream of the PNA during a fuel cut event and while the exhaust gas temperature is between a lower threshold temperature and the upper threshold temperature. In this way, degradation of the NOx storage capacity may be inferred based on an amount of NOx released from the PNA and independent of a NOx storage measurement.

Abstract: An exhaust system includes an exhaust duct having an internal surface defining an exhaust gas passage extending along an axis. At least one sensor opening is in the exhaust duct and is configured to receive an exhaust gas sensor. A wall is positioned within the exhaust gas passage to extend at least partially around the at least one sensor opening. The wall has an inner wall surface defining an internal volume. A plurality of inlet pipes are in fluid communication with the internal volume, and each inlet pipe extends from a first end open to the internal volume to a second end that is distal from the first end. Each inlet pipe includes a plurality of inlet apertures.

Abstract: A control device to be applied to an internal combustion engine having a fuel reformation cylinder and an output cylinder, wherein the compression end gas temperature of the fuel reformation cylinder is adjusted by changing an EGR gas amount, an effective compression ratio, or a polytropic number according to an equivalence ratio in the fuel reformation cylinder so as to achieve a target concentration of a specific gas component in reformed fuel generated in the fuel reformation cylinder. The target concentration is defined according to a required engine power.

Abstract: An internal combustion engine in which when the gas temperature of a fuel reformation chamber when a piston in a fuel reformation cylinder reaches the compression top dead point is estimated to be equal to or higher than a soot generation lower limit temperature set according to an equivalence ratio of the fuel reformation chamber, a reaction gas temperature adjusting operation for suppressing or reducing an increase in the reaction gas temperature in the fuel reformation chamber is executed. Further, a closing timing of an air-intake valve is changed to reduce an effective compression ratio of the fuel reformation chamber.

Abstract: Methods and systems are provided for adjusting amount of directly injected fuel scavenged via a second exhaust manifold of a split exhaust engine system. In one example, a method may include adjusting a start of injection of a fuel direct injection into an engine cylinder, the cylinder including a first exhaust valve coupled to a first exhaust manifold and a second exhaust valve coupled to a second exhaust manifold, the second exhaust manifold coupled to an intake of the engine, based on a closing timing of the second exhaust valve and dependent on an operating condition, and adjusting a position of a bypass valve of the second exhaust manifold based on the adjusted start of injection. In this way, the amount of scavenged fuel may be increased or decreased based on the operating condition.

Abstract: A catalyst abnormality diagnostic device is configured to diagnose an abnormality of a first purification catalyst having an oxygen storage capacity and a second purification catalyst having the oxygen storage capacity and a function of a particulate filter provided on an exhaust passage on a downstream side of the first purification catalyst. The catalyst abnormality diagnostic device adjusts a fuel injection amount so that an air-fuel ratio of an exhaust gas is repeatedly in a rich state and a lean state, obtains a first determination value indicating a catalytic performance of the first purification catalyst, obtains a second determination value indicating a catalytic performance of the second purification catalyst, and determines whether there is an abnormality in one or both of the first purification catalyst and the second purification catalyst on the basis of the first determination value, the second determination value, and a predetermined determination reference value.

Abstract: Methods, devices, controllers, and algorithms are described for operating an internal combustion engine wherein at least some firing opportunities utilize low temperature gasoline combustion (LTGC). Other firing opportunities may be skipped or utilize some other type of combustion, such as spark ignition. The nature of any particular firing opportunity is dynamically determined during engine operation, often on a firing opportunity by firing opportunity basis. Firings that utilize LTGC produce little, if any, nitrous oxides in the exhaust stream and thus, in some implementations, may require no aftertreatment system to remove them from the exhaust stream.

Abstract: An amount of deposition of intramural PM in a particulate filter is estimated with a high degree of accuracy. A controller obtains, as a correlation between a reference value of an intramural PM deposition amount and an oxygen storage capacity of the catalyst, a change over time of an oxygen storage capacity of the catalyst according to a change of a filter PM deposition amount in a period of time from a point in time at which the filter PM deposition amount is substantially zero to a point in time at which the oxygen storage capacity of the catalyst, which becomes larger according to an increase of the filter PM deposition amount, reaches a maximum value. Further, the controller estimates a current intramural PM deposition amount based on a current oxygen storage capacity of the catalyst and the correlation.

Abstract: An apparatus which detects particulate matter is provided. This apparatus estimates a volume of water inside an exhaust passage using estimation sections. When an estimated volume of water is larger than a water drainage threshold, an element portion is heated using a heater by the first temperature range controller, in a temperature range which resists water-induced cracking independent of a volume of water droplets. If the estimated volume of water is less than a water drainage threshold, the water drainage determination section determines that the water drainage of the exhaust passage is completed. Additionally, if it is estimated that the water drainage is completed, the element portion is heated by a second temperature controller at temperature lower than a starting temperature of combustion of particulate matter and in order to repel water adhered onto the element portion in a water-repellent temperature range for a predetermined period.

Abstract: An exhaust system, especially for an internal combustion engine in a vehicle, includes at least one sensor carrier unit (20) carried on an exhaust gas-carrying element (14). The sensor carrier unit (20) includes a sensor carrier element (22) fixed to the exhaust gas-carrying element (14). A plurality of sensor pipe connections (24, 26, 28), that are fitted or can be fitted with sensors, are provided on the sensor carrier element (22). The plurality of sensor pipe connections (24, 26, 28) each have at least one respective sensor-mounting/measuring opening (30) formed therein.

Abstract: A system for control of an internal combustion system having subsystems, each with different response times. Subsystems may include a fuel system, an air handling system, and an aftertreatment system, each being operated in response to a set of reference values generated by a respective target determiner. Calibration of each subsystem may be performed independently. The fuel system is controlled at a first time constant. The air handling system is controlled on the order of a second time constant slower than the first time constant. The aftertreatment system is controlled on the order of a third time constant slower than the second time constant. A subsystem manager is optionally in operative communication with each target determiner to coordinate control. Generally, dynamic parameters from slower subsystems are treated as static parameters when determining reference values for controlling a faster subsystem.

Abstract: Methods and systems are described for controlling fuel injection in an engine equipped with a dual injector system including a port injector and a direct injector. A ratio of port injected fuel to direct injected fuel is adjusted based at least on intake valve temperature. The proportion of fuel port injected into a cylinder is increased as the intake valve temperature for the given cylinder increases to improve fuel vaporization in the intake port.

Abstract: A multi-stage reconfigurable air intake and exhaust system for a piston engine having first and second rows of cylinders forming a V configuration. The system includes plural stage packages having inter-related components that can be connected and changed to form different air intake and exhaust gas configurations. There is particularly provided a Stage 1 package with first and second exhaust manifolds adapted to be respectively secured to the first and second rows of cylinders, and a Stage 2 package with a turbo exhaust manifold adapted for mounting a turbocharger, and also adapted to be secured to the first row of cylinders in lieu of the first exhaust manifold, and a crossover pipe assembly adapted for coupling the turbo exhaust manifold to the second exhaust manifold.

Abstract: An exhaust device of a turbocharger vehicle includes: a catalyst converter diagonally arranged in a vertical direction toward the ground as being connected with an outlet of a streamlined exhaust connecting pipe which is bent at 95° or more, wherein the streamlined exhaust connecting pipe is connected between an outlet of a turbocharger and the catalytic converter.

Abstract: An internal combustion engine 1 is provided, in an exhaust passage thereof with an electrochemical reactor including: an ion conductive solid electrolyte layer; an anode layer arranged on a surface of the solid electrolyte layer; and a cathode layer arranged on a surface of the solid electrolyte layer and able to hold NOX. The engine includes a current control device for controlling the current supplied to the electrochemical reactor so as to flow from the anode layer through the solid electrolyte layer to the cathode layer. The current control device is configured so as to supply current to the electrochemical reactor at least temporarily while that internal combustion engine is stopped.

Abstract: The present invention provides a method and system for caching time series data. A computer system for caching time series data is disclosed. The computer system comprises one or more processors, at least one cache, and a computer readable storage medium. The computer readable storage medium contains instructions that, when executed by the one or more processors, causes the one or more processors to perform a set of steps comprising fetching the time series data from a time series data source, calculating one or more expiry timestamps, grouping the plurality of time series datum in to one or more time data chunks based on the one or more expiry timestamps, and storing a copy of the time series data and the one or more expiry timestamps in the at least one cache.

Abstract: An electronic central unit is configured to control a voltage application device to execute applied voltage sweep and obtain an output current that flows between a first electrode and a second electrode of an electrochemical cell. The electronic control unit is configured to detect either one of presence or absence of sulfur oxides in a specified concentration or higher in exhaust gas and a concentration of sulfur oxides in the exhaust gas based on the output current. The electronic control unit is configured to execute one of a specified determination and a specified detection based on a specified parameter. Accordingly, it is possible to accurately determine the presence or the absence of sulfur oxides in the specified concentration or higher that are contained in exhaust gas or detect the concentration of sulfur oxides in the exhaust gas.

Abstract: A system and method is provided for estimating engine exhaust nitrogen oxide sensor signal instability in transient conditions, for example when rapid changes occur in driver demanded torque, and for eliminating fluctuations in EONOx sensor signal status, in order to have more robust on-board diagnostics monitoring and exhaust nitrogen oxide control. The system and method predicts EONOx sensor signal instability by comparing a calculated pedal based driver demand torque delta to calculated instability thresholds and instability threshold hysteresis margins, and generates instability flags. The system and method further validates any predicted EONOx sensor signal instability by observation. Upon validation of the predicted EONOx sensor signal instability, the system and method latches the EONOx sensor signal status to a stable value.

Abstract: In certain embodiments, a method and an apparatus which can be implemented with a simplified and inexpensive configuration without causing a misfire in a combustion state. In a fuel-Cetane-number estimation method according to embodiments, a map which specifies a relationship between the Cetane number and a control parameter at which NOx concentration of exhaust gas reaches a predetermined value is prepared in advance. Then, the control parameter is controlled variably to detect transition of the NOx concentration of the exhaust gas of the internal combustion engine, and thereby the control parameter of the internal combustion engine at which the NOx concentration has reached the predetermined value is obtained, and the Cetane number which corresponds to the obtained control parameter is estimated on the basis of the map.

Abstract: Provided is an exhaust purification system including: an NOx occlusion reduction type catalyst that is provided in an exhaust system of an internal combustion engine, and occludes NOx when an exhaust gas is in a lean state, and reduces the NOx when the exhaust gas is in a rich state; a regeneration control unit that executes a regeneration process of bringing the exhaust gas into a rich state to reduce the NOx occluded in the NOx occlusion reduction type catalyst; a storing unit that stores an exhaust lambda prediction value in advance when the regeneration process is executed; a reduction amount estimating unit that estimates an NOx reduction amount when the regeneration process is executed; and a prohibition unit that prohibits the execution of the regeneration process by the regeneration control unit when the estimated NOx reduction amount is less than a predetermined lower limit threshold.

Abstract: In a construction in which a turbine and an exhaust gas purification catalyst are arranged close to each other, and in which an exhaust gas sensor is arranged in an exhaust passage between the turbine and the exhaust gas purification catalyst, the exhaust gas sensor is suppressed from getting wet with condensed water. In an exhaust system for an internal combustion engine, an exhaust gas sensor is arranged in a circumferential direction of a specific exhaust passage in a position except a range which is reached by a bypass exhaust gas carried away by a turbine swirling flow.

Abstract: An exhaust purification system of an internal combustion engine comprises an air-fuel ratio control device controlling an air-fuel ratio of the inflowing exhaust gas to a target air-fuel ratio. If a first judged condition wherein an estimated amount of change of an oxygen storage amount of the catalyst when the target air-fuel ratio is maintained at the first set air-fuel ratio is equal to or greater than a first reference amount, and a second judged condition wherein a difference of an air-fuel ratio detected by the upstream side air-fuel ratio sensor and a stoichiometric air-fuel ratio is equal to or greater than a difference of a second judged air-fuel ratio and a stoichiometric air-fuel ratio are satisfied, the air-fuel ratio control device switches the target air-fuel ratio from the first set air-fuel ratio to the second set air-fuel ratio when the first judged condition and second judged condition are satisfied.

Abstract: Evaluation method of exhaust gas simulation capable of simply and appropriately evaluating the validity of the simulation is provided. In analysis data, an analysis amplitude curve is calculated in which a change in the concentration of virtual exhaust gas at the observation point in the converged pipe portion is plotted, and an analysis time interval between the zero point and the reference point in the analysis amplitude curve is plotted. In actual measurement data, an actual amplitude curve is provided in which a change in the specific gas component at an observation point is measured with time, and an actual time interval is provided in which a time interval from a zero point to a reference point in the actual amplitude curve. The analysis data is determined as valid when a difference between the analysis time interval and the actual time interval is within a predetermined correlation range.