The disclosure relates to a method for determining a parameter characterizing the anti-knock property of a fuel using a test engine having at least one cylinder, wherein the fuel undergoes combustion inside the cylinder during the course of the method and the cylinder pressure generated by the combustion is detected using a pressure sensor. The pressure sensor has a linear pressure output signal curve. A parameter characterizing the anti-knock property of the fuel is calculated based on the output signal of the pressure sensor. The calculation is done using a mathematical model that considers the deviation of the pressure output signal curve of the pressure sensor being used from the pressure output signal curve of a pick-up sensor prescribed in the ASTM D2699 standard. Moreover, a test system to determine the anti-knock property of a fuel is disclosed.

An apparatus comprises a first circuit and a second circuit. The first circuit is structured to determine that a combustion cylinder is operating in a transition period between an exhaust stroke and an intake stroke of the combustion cylinder. The second circuit is structured to provide an injection command during the transition period to a fuel injector associated with the combustion cylinder, the injection command being to inject fuel into a combustion chamber of the combustion cylinder such that at least a portion of the fuel escapes from the combustion chamber through an exhaust port of the combustion cylinder.

A controller for an internal combustion engine includes a fuel introduction process of introducing an air-fuel mixture containing fuel injected by a fuel injection valve into an exhaust passage without burning the air-fuel mixture in a cylinder. The fuel introduction processor is configured to perform, during the execution of the fuel introduction process, a determination process of determining whether afterfire, in which the air-fuel mixture burns at an upstream side of a three-way catalyst device in the exhaust passage, has occurred and a stopping process of stopping the fuel introduction process when determining in the determination process that the afterfire has occurred.

A method for adjusting an air-fuel ratio of a turbocharged engine that operates without blow though and with blow through is disclosed. In one example, the method provides a way to provide a feed forward fuel adjustment in the presence of engine blow though so that a closed loop controller does not have to exceed its range of control authority.

A deterioration determination apparatus is usable with an ammonia sensor that includes an ammonia element portion that includes, a solid electrolyte, an ammonia electrode, and a reference electrode. The deterioration determining apparatus compares a first evaluation value and a second evaluation value, and determines whether deterioration has occurred in the ammonia element portion of the ammonia sensor at an evaluation time or subsequent to the evaluation time. The first evaluation value is based on a first sensor current obtained when a DC voltage is applied between the ammonia electrode and the reference electrode of the ammonia element portion at an initial time that is during an initial use period of the ammonia sensor. The second evaluation value is based on a second sensor current obtained when the DC voltage is applied between the ammonia electrode and the reference electrode subsequent to the initial period of use of the ammonia sensor.

The present invention is an on-board vehicle emissions measurement system. The system comprises at least one sensor (CAP) downstream from the aftertreatment system, and optionally a sensor plugged into the vehicle diagnostics port, and a computer (SIN) including models (MOD VEH, MOD MOD, MOD POT). According to the invention, emissions determination is based on the signal from sensor (CAP) and on models (MOD VEH, MOD MOT, MOD POT).

A catalyst deterioration detection system 1 comprises an air-fuel ratio sensor 41, a current detection device 61, a voltage application device 60, a voltage control part 71, an air-fuel ratio control part 72 and a deterioration judging part 73. The air-fuel ratio control part executes fuel cut control, and, after the fuel cut control, executes rich control. The voltage control part, if judging that the air-fuel ratio of the outflowing exhaust gas has reached the stoichiometric air-fuel ratio when setting the applied voltage to a first voltage in a limit current region during the rich control, changes the applied voltage from the first voltage to a second voltage in a limit current region. The deterioration judging part judges the degree of deterioration of the catalyst based on the output current of the air-fuel ratio sensor when the applied voltage is set to the second voltage.

An engine controller executes a fuel introduction process of introducing, in a state in which the crankshaft of an internal combustion engine is rotating, air-fuel mixture that contains fuel injected by a fuel injection valve into the exhaust passage without burning the air-fuel mixture in the cylinder. When the oxygen concentration of exit gas that has passed through a three-way catalyst decreases during the execution of the fuel introduction process, the engine controller executes a stopping process of stopping the fuel introduction process.

A controller for an engine estimates a temperature of the exhaust gas and controls the engine according to the estimated exhaust temperature. The controller changes the air-fuel ratio to a stoichiometric air-fuel ratio or leaner. The controller calculates the progress of combustion on the basis of signals of sensors, and estimates an exhaust temperature. In the case where the air-fuel ratio is the stoichiometric air-fuel ratio, the controller estimates the exhaust temperature on the basis of the progress of the combustion, the engine temperature, and a first relationship that is at least defined between the progress of the combustion and the exhaust temperature, . In the case where the air-fuel ratio is lean, the controller estimates the exhaust temperature on the basis of the progress of the combustion, the engine temperature, and a second relationship that differs from the first relationship.

A regeneration control system for an oxidation catalyst in an internal combustion engine includes a temperature sensor to produce a temperature signal indicative of an exhaust inlet temperature that is below a regeneration temperature for accumulated hydrocarbons on the oxidation catalyst, an electrically actuated boost leakage valve, and a regeneration control unit. The regeneration control unit commands an adjustment to the position of the electrically actuated boost leakage valve to increase leaked boost to increase exhaust temperature to the regeneration temperature by way of increased air-fuel ratio. Related methodology is disclosed.