Abstract: An internal combustion engine is provided. The engine comprises at least one combustion chamber. The engine is suitable for various types of fuel. The engine, depending on fuel type, may have at least one spark plug. The engine uses an external source of compressed oxidant, such as air, which is delivered from a compressor and/or pressurized storage tank. Compressed oxidant, such as air, is delivered directly into the combustion chamber. Fuel is delivered directly into the combustion chamber. Oxidant and fuel mixture is ignited either by means of a spark plug, laser ignition, or by other means, or ignites spontaneously, depending on fuel type and pressure in the combustion chamber. The engine may comprise at least one cylinder, or may be of rotary or other type. A hybrid vehicle based on such an engine is provided. An automatic parking system for such a vehicle is provided.

Abstract: A cylinder for an internal combustion engine having co-annular dual pistons. The cylinder has a main cylinder having a main cylinder wall and a cylinder head, a first or outer piston having an annular crown, an inner cylinder wall that defines an inner cylinder, and an annular outer sidewall extending from the periphery of the crown, an inner piston having a crown, and an annular inner sidewall extending from the periphery of the crown. A solenoid-actuated pin selectively secures the outer piston with the main cylinder during a portion of each cylinder cycle. The inner piston reciprocates within the inner cylinder during both the air inlet and compression strokes, while the outer piston reciprocates within the main cylinder only during the power stroke and the exhaust stroke, to increase the piston crown surface area exposed to the combustion gases to maximize the power and efficiency.

Abstract: The invention relates to a control method and system for an internal combustion engine incorporating an engine shut-off valve, and in particular an air intake shut-off valve for a diesel or gas-fueled engine. The control system comprises a valve controller unit including a receiver capable of receiving sensor signals, and being in communication with the shut-off valve for permitting or preventing air flow in the shut-off valve upon receiving a triggering sensor signal.

Abstract: Methods and systems are provided for reducing late burn induced cylinder pre-ignition events. Forced entry of residuals from a late burning cylinder into a neighboring cylinder may be detected based on engine block vibrations sensed in a window during an open exhaust valve of the late burning cylinder. In response to the entry of residuals, a pre-ignition mitigating action, such as fuel enrichment or deactivation, is performed in the neighboring cylinder.

Abstract: Conventional spark-ignited gas engines with a mechanically controlled fuel feed valve have several disadvantages in terms of operation, expensive control, irregular combustion or unstable and unreliable operation, which in turn can lead to operational and mechanical problems. In order to eliminate these disadvantages it is suggested, according to the invention, that a controlled valve is installed in the fuel line upstream of the fuel feed valve so that in the fuel line between fuel feed valve and controlled valve a defined intermediate volume is created and gaseous fuel is fed via the controlled valve into the intermediate volume.

Abstract: A differential stroke reciprocating internal combustion engine having an engine shaft and a piston configured to reciprocate within a cylinder chamber includes an inner piston part, a piston stem coupled at a first end to said inner piston part, an outer piston part which serves as a carrier for said inner piston part and is connected to said engine shaft, wherein said inner piston part is configured to operate on a cycle different from that of said outer piston part, and a control and linkage assembly coupled to said engine at an anchor point, and said control and linkage assembly pivotally coupled at a second end of said piston stem defining a copy point, wherein said control and linkage assembly guides and defines the movement of said copy point to be substantially aligned with an axis of said cylinder chamber.

Abstract: The invention relates to a device for dispensing a liquid additive into a fuel circulation circuit for an internal combustion engine, comprising a reservoir (12) of liquid additive allowing an additive to be distributed into the fuel circulation circuit by means of a distribution line (16), characterized in that it comprises an additive chamber (22) in communication with the fuel circulation circuit and at least one wall (32) that is mobile and fluidtight between said additive chamber and the additive reservoir which, on the one hand, provides a fluidtight division and, on the other hand, maintains equal pressure between the additive in the additive reservoir and the fuel in the additive chamber.

Abstract: A liquid cooled internal combustion engine having a bypass line with a controllable shut off element so that coolant can bypass the cylinder head in certain engine operating conditions. The bypass line branches off from the coolant circuit upstream of the cylinder head and returns to the coolant circuit downstream of the cylinder head.

Abstract: A control device for an internal combustion engine. An object of the present invention is to provide a control device for an international combustion engine for highly accurate absolute pressure correction irrespective of the length of an adiabatic compression stroke period. When the number of cylinders in an engine is n (n is an integer of 2 or more), an adiabatic compression stroke period of one cylinder preceding another cylinder to be corrected into its absolute pressure by a 1/n cycle (ignition timing —IVC) is compared with a threshold CATH (step 100). In the step 100, the absolute pressure correction is carried out based on PV?=constant when the adiabatic compression stroke period is longer than the threshold CATH (step 110). On the other hand, the absolute pressure correction is carried out based on a value PIP detected by an intake pipe pressure sensor when the adiabatic compression stroke period is shorter than the threshold CATH.

Abstract: Systems and methods for fuel tank tube routing and valve placement to prevent fuel leaks into the evaporative emissions system are disclosed. An embodiment provides a vehicle fuel tank venting system that uses strategically placed valves and a low profile tube routing to prevent the leakage of liquid fuel to an evaporative emission system in the event of a valve failure. In one aspect, a first and second outlet valve may be positioned such that at least one of the valves is above a full fuel level for a desired range of fuel tank tilted positions. Among the desired range, when the first valve is submerged in fuel, at least a portion of the first outlet tube may be above the full fuel level, and when the second valve is submerged, at least a portion of the second outlet tube may be above the full fuel level.

Abstract: The application relates to spark initiation under varied aircharge density and composition. An engine is disclosed comprising at least two cylinders with spark plugs therein; an integrated exhaust manifold, the integrated exhaust manifold having a wall portion and an adjustable shutoff element within the wall portion wherein the wall portion divides exhaust pipes of the at least two cylinders and the adjustable shutoff element allows exhaust gas from a first cylinder into an exhaust pipe of an adjacent cylinder. Hot exhaust gas may be taken into an adjacent cylinder serving as ignition gas and allowing the engine of the present disclosure to undergo spark ignition at low loads, or autoignition at high loads.

Abstract: An inter-cylinder air-fuel ratio imbalance determination apparatus (determination apparatus) according to the present invention obtains, as an “EGR supplying state imbalance determination parameter”, a value corresponding to a differential value d(abyfs)dt of a detected air-fuel ratio abyfs represented by an output value of an air-fuel ratio sensor when an EGR gas is being supplied, and obtains, as an “EGR stop state imbalance determination parameter”, a value corresponding to a differential value d(abyfs)dt when an EGR gas supply is being stopped. The determination apparatus obtains an “EGR-causing imbalance determination parameter Pegr” by subtracting the EGR stop state imbalance determination parameter Poff from the EGR supplying state imbalance determination parameter Pon, and determines that an inter-cylinder air-fuel ratio imbalance state has occurred due to the supply of the EGR gas when the parameter Pegr is larger than a threshold Pegrth.

Abstract: A wide-band damper is designed for charge air lines of an internal combustion engine with turbocharger. The wide-band damper has an inlet and an outlet. Proceeding from the inlet, at least three slot chambers are arranged axially in series. The slot chambers are dimensioned for different frequencies f1, f2 and f3. At least three gap chambers are provided, which are arranged axially in series and axially downstream of the at least three slot chambers. The gap chambers are dimensioned for different frequencies f6, f7 and f8. Each of the frequencies f1, f2 and f3 of the slot chambers is lower than each of the frequencies f6, f7 and f8 of the gap chambers.

Abstract: Various embodiments include a gaseous fueled engine and fuel tank assemblies, in particular the location and attitudes of the fuel tanks. One or more fuel tanks are attached to the power tool. The fuel tank housing has slots for air flow to heat the fuel tank to off-set the drop in fuel temperature due to latent heat of evaporation of liquefied petroleum fuels. Gaseous fuel may include LPG, Butane, LNG, H2, etc.

Abstract: A disc damper for a charge air line of an internal combustion engine that has a turbocharger. The disc damper includes an inlet, an outlet, and at least one slit chamber disposed between the inlet and outlet. Starting from the inlet, at least two gap chambers are provided downstream of the slit chamber and disposed axially one after the other. At least one of the following features is fulfilled: a) the slit chamber has a radial inner dimension that changes in the circumferential direction and/or b) the slit chamber has axial inner dimensions that change in the circumferential direction, and/or at least one gap chamber comprises radial inner dimensions that change in the circumferential direction.

Abstract: A heat accumulator for a vehicle engine, comprising storing coolant in a flexible storage container with an inner body and an outer body, with an insulation device arranged between the bodies, and an inflow and an outflow for the coolant wherein the storage container can expand and deflate in response to the amount of coolant stored. The flexible storage container allows for the heat accumulator to conform to various under hood space constraints.

Abstract: A fuel injection amount control apparatus for an internal combustion engine includes an ECU that commands a learning-purpose injection when a first learning condition regarding operation state and a second learning condition regarding load connection state are satisfied, and calculates an injection performance value that corresponds to the actual injection amount based on the amount of change in rotation speed, and further determines whether a delay of the learning process is permitted based on whether the learning process, despite occurrence of the delay, can be completed before the injector performance reaches a permissible limit value, and forces, when the delay is not permitted, the load connection state to be a specific connection state so as to satisfy the second learning condition. When it is determined that the delay of the learning process is permitted, the delay is permitted until the two learning conditions are satisfied.

Abstract: A system is disclosed for use with an engine. The system may have an intake manifold configured to direct air into combustion chambers of the engine. The system may also have an auxiliary device and an exhaust manifold configured to direct exhaust from the combustion chambers of the engine through the auxiliary device to the atmosphere. The system may additionally have a conduit associated with fewer than all of the combustion chambers of the engine and extending to the auxiliary device in parallel with the exhaust manifold, and an auxiliary valve disposed within the conduit and selectively movable between a flow-passing position and a flow-blocking position.

Abstract: A straight shaft non-planetating rotary piston engine includes a housing and at least one rotating piston mounted for circular rotation about an axis within the housing. The piston and the housing define an expansible combustion chamber that produces at least one combustion events for every rotation of the piston about the axis. The invention also includes a moveable cylinder head having a profile roller. The profile roller cooperates with an open face profile impressed into a rotary encoder. The open face profile is configured to pull the cylinder head into near-contact with the rotating piston face, and the moveable cylinder head is spring biased to repel the moveable cylinder head away from the rotating piston face.

Abstract: A carburetor having an inlet opening that includes a pair of concavities operative to direct air toward the metering rod of the carburetor. A carburetor having an inlet opening that includes an arcuate manifold adjacent to the inlet opening and in fluid communication with a fuel reservoir. A carburetor having a slide assembly that includes a positioning mechanism operative to adjust the position of the metering rod relative to the throttle slide. A throttle slide that includes a flow guide that bisects an arcuate relief on an underside thereof. A method for configuring the throat of a carburetor that includes an upper portion of a first diameter and a lower portion of a second diameter that is offset from the first diameter. The method comprises deriving an optimum size for the first and second diameters and the offset based on the pumping efficiency and operating parameters of the engine.

Abstract: Embodiments for injecting air into exhaust ports of an engine are provided. In one example, a multi-cylinder engine method comprises combusting a rich air-fuel mixture, injecting air into a first cylinder's exhaust port and not into a second cylinder's exhaust port during the first cylinder's exhaust stroke, and injecting air into the second cylinder's exhaust port and not into the first cylinder's exhaust port during the second cylinder's exhaust stroke. In this way, injection into each exhaust port may be timed with exhaust release into each exhaust port.

Abstract: A snowmobile coolant system that includes an engine outlet line, an engine inlet line, and an inlet thermostat. The engine outlet line provides coolant flow between an engine and a heat exchanger of the snowmobile. The engine inlet line provides coolant flow between the heat exchanger and the engine. The inlet thermostat is positioned in the engine inlet line and is operable between open and closed states based on a temperature of coolant flowing from the heat exchanger to the inlet thermostat.

Abstract: A method for actuating an element (22) in the air supply tract (29) of an internal combustion engine (19), characterized in that the element (22) is actuated such that it opens the air supply tract (29) before the pinion (10) engages into the toothed ring (16) of the internal combustion engine (19).

Abstract: A vehicle has at least one component which is cooled by a cooling air mass flow delivered from a conveying device such as a fan or a spoiler. A nominal value is predetermined for the cooling air mass flow which, for an assumed maximum thermal loading of the component, cools adequately for operation of the component. A control device controls an intensity of the cooling air mass flow and dimensions it, taking into consideration thermal demands of the component at least in an upper driving speed range, such that a sum of a power consumption of the component, of the conveying device and of a portion of a traction power of the vehicle that is allotted to the delivery of the cooling air mass flow is smaller than a sum of the power consumption of the component, the conveying device and the portion that is allotted to the delivery of the cooling air mass flow at the predetermined nominal value thereof, of a traction power of the vehicle.

Abstract: A method for correcting a total cylinder air flow during scavenging by way of an oxygen sensor is disclosed. Additionally, cylinder trapped air amount and cylinder scavenging air amount are adjusted based on the corrected total cylinder air flow. The approach may reduce sensitivity between cylinder air flow estimates and fuel supplied for combustion.

Abstract: Methods and systems are provided for addressing pre-ignition that may be induced in response to actions taken to mitigate a cylinder misfire. An amount of engine load limiting applied may be adjusted to reduce the likelihood pre-ignition while also addressing component over-temperature issues. By limiting an engine load while shutting off fuel in a misfiring cylinder, and while combusting a lean air-fuel mixture in the remaining cylinders, pre-ignition induced by the misfire-mitigating lean combustion conditions can be reduced.

Abstract: An inter-cylinder air-fuel imbalance determination apparatus according to the present invention obtains, based on the output value of the air-fuel ratio sensor, an air-fuel ratio fluctuation indicating amount whose absolute value becomes larger as a fluctuation of the air-fuel ratio of the exhaust gas passing through the air-fuel ratio sensor becomes larger, and further obtains an imbalance determination parameter which becomes larger as an absolute value of the air-fuel ratio fluctuation indicating amount becomes larger. In addition, the determination apparatus obtains an average value of the air-fuel ratio of the exhaust gas when the imbalance determination parameter is being obtained, and obtains an imbalance determination threshold which becomes smaller as the average value of the air-fuel ratio is closer to the stoichiometric air-fuel ratio.

Abstract: An air induction system hydrocarbon trap is provided. In one example, the hydrocarbon trap includes an adsorber roll including an adsorbing material and a corrugate support, where the corrugate support is rolled with the adsorbing material to form a wound adsorber roll. A housing is further provided to retain the adsorber roll. A housing cap may be coupled to the housing.

Abstract: A method for determining cylinder blow-through air via engine volumetric efficiency is disclosed. In one example, the method provides a way to adjust cylinder blow-through to promote and control a reaction in an exhaust after treatment device. The approach may simplify cylinder blow-through calculations and improve engine emissions via providing improved control of constituents reaching an exhaust after treatment device.

Abstract: The present invention is an aero engine that is provided with compression combustion and weighs less than 725 lbs. The present invention is further a method of forming the aero engine.

Abstract: A control system for an internal combustion engine performs output control so that an engine output coincides with demand output by changing intake air flow rate or ignition timing of the engine. Output reduction control, wherein engine output is reduced, is performed when the demand output decreases. A retard limit output is calculated, and a retard limit intake air flow rate is calculated when the demand output is less than the retard limit output. The engine output is made to coincide with the demand output by retarding the ignition timing when the demand output is equal or greater than the retard limit output. When the demand output is less than the retard limit output, the ignition timing is retard to the limit and the intake air flow rate is controlled so as to coincide with the retard limit intake air flow rate.

Abstract: When performing a learning control of a fuel injection quantity, a fuel injection control apparatus adds a pilot fuel injection during the working state of a diesel engine when a learning data item (as a fuel injection amount correction value) is calculated per cylinder and fuel pressure. The apparatus compares, based on a combustion stroke of a target cylinder, a work load obtained during an ordinary fuel injection with a work load obtained during the pilot fuel injection. The apparatus calculates a learning data item for the target cylinder in order to correct an actual fuel injection quantity in the target cylinder with the learning data item so that the actual fuel injection quantity approaches a target fuel injection quantity.

Abstract: A combustion control system for a direct injection engine includes a mean effective pressure (MEP) determination module, a coefficient of variation (COV) determination module, a spark timing module, and a fuel control module. The MEP determination module determines a MEP for a first combustion event of a cylinder based on cylinder pressure measured by a cylinder pressure sensor during the first combustion event. The COV determination module determines a COV for the cylinder based on the MEP. The spark timing module selectively sets a spark timing for a second combustion event of the cylinder based on the COV. The second combustion event is after the first combustion event. The fuel control module that selectively provides fuel for the second combustion event based on the COV.

Abstract: A combustible fluid-operated orbital engine having sets of cooperating cylinder and piston members with respective parallel axes of rotation. Respective cylinder and piston carrier wheels with respective axes of rotation parallel to the piston/cylinder axes of rotation carrying the pistons/cylinders circularly and orbitally and at all times in opposed relation on a common longitudinal axis along intersecting counter paths. Respective gearing structures or belts/sprockets supported by the cylinder and piston carrier wheels rotate the pistons/cylinders counter to their circular motion direction to maintain their opposed relation for their periodic interfittment when their respective paths intersect. A combustible fluid supply is provided to the cylinder member for combustion coincident with the periodic interfittment in engine operating relation. The pistons/cylinders may include ceramic material. The compression sealing system is located in the entry of each cylinder rather than being connected to the piston.

Abstract: A structure for preventing surge of a 2-cylinder engine may include a first line communicating a crank room of the engine with a cylinder head cover, a first valve which may be disposed on the first line and allows a fluid within the crank room to flow into the cylinder head cover, a second line communicating the crank room of the engine with an intake manifold and a second valve which may be disposed on the second line and allows a fluid within the intake manifold into the crank room.

Abstract: A unitary assembly for retaining the various components of a fuel control system on a vehicle, wherein the assembly includes a unitary module at least partially structured in the form of a mounting assembly operative to contain and support at least a portion of the fuel control system specifically including a containment structure or at least one fuel tank for storing and operatively disposing a fuel supply associated with the fuel control system. An electronic control unit of the fuel control system is structured to facilitate metering and distribution of an operative fuel mixture which may include an alternate fuel as well as a conventional distillate fuel. The module and the mounting assembly are cooperatively structured to collectively retain the electronic control unit, the containment structure and at least a portion of a remainder of the fuel control system as a self-contained unit on the vehicle.

Abstract: Various methods are described for controlling engine operation for an engine having a turbocharger and direction injection. One example method includes performing at least a first and second injection in response to a driver action. The first and second injection may be performed during a cylinder cycle, the first injection generating a lean combustion and the second injection injected after combustion such that it exits the cylinder unburned into the exhaust upstream of a turbine of the turbocharger.

Abstract: Disclosed is an internal combustion engine gas cycle modification process, comprising venting, which allows for some automatic gas transfer from intake to exhaust or vice versa, through the cylinder, in the compression or expansion strokes, by a second or third opening of either the intake or the exhaust valves, which is done by using a second or third auxiliary lobe on the intake or the exhaust cams, which however are much smaller than the normal lobes. Seven gas cycle modifications are explained and compared, each of which reduces NOx by 300-9,000× and cleans emission in the cylinder. On the same fuel consumption, all these modified gas cycles preserve torque and power. One however, increases high engine speed power and torque by over 70%. That may be exchanged for fuel savings. Double and triple lobe cams made the same way and cost the same as single lobe cams. It substitutes after-treatments.

Abstract: A method for compensating for thermal transient conditions of an engine that can cause valve growth or contraction is disclosed. In one example, the method provides cylinder air amount compensation during non-blow-through and blow-through conditions. The approach may improve cylinder air amount estimates, thereby improving engine emissions.

Abstract: A method for determining a cylinder charge of an internal-combustion engine having valves with a variable valve gear, may include determining a maximum intake valve lift, calculating a standardized cylinder charge relative to at least one of a defined intake spread of an intake valve opening phase and a defined exhaust spread of an exhaust valve opening phase, as a function of the maximum intake valve lift, determining an overlap value, which characterizes an actual overlap of the intake valve opening phase and the exhaust valve opening phase, and determining a corrected cylinder charge based on the standardized cylinder charge and the overlap value.

Abstract: Engine idle control includes commanding a preferred engine idle speed and operating the engine at a mean best torque spark timing, monitoring an engine speed and an engine air/fuel ratio, commanding an injected fuel mass corresponding to the monitored engine speed and the preferred engine idle speed, and commanding a cylinder intake air mass corresponding to the injected fuel mass, the engine air/fuel ratio and a preferred engine air/fuel ratio.

Abstract: A first judgment circuit and a second judgment circuit are adapted to set a judging signal high when a judgment data sent from a microprocessor indicates failure. The high level judging signal triggers a forced idle command connected to a motor driver, to be high level whereby the motor is forcibly suspended. Subsequently, when a reset command is accidentally transmitted by the microprocessor due to an unexpected fault, a first judging signal from the first judgment circuit is reset to low level. However, a second judging signal from the second judgment circuit remains high level. As a result, the forced idle command stays high level.

Abstract: An internal combustion engine is provided. The engine comprises at least one combustion chamber. The engine is suitable for various types of fuel. The engine, depending on fuel type, may have at least one spark plug. The engine uses an external source of compressed oxidant, such as air, which is delivered from a compressor and/or pressurized storage tank. Compressed oxidant, such as air, is delivered directly into the combustion chamber. Fuel is delivered directly into the combustion chamber. Oxidant and fuel mixture is ignited either by means of a spark plug, laser ignition, or by other means, or ignites spontaneously, depending on fuel type and pressure in the combustion chamber. The engine may comprise at least one cylinder, or may be of rotary or other type. A hybrid vehicle based on such an engine is provided. An automatic parking system for such a vehicle is provided.

Abstract: An internal combustion engine system includes: an internal combustion engine; a valve regulating exhaust gas flow rate to an intake system; an exhaust gas recirculation system opening the valve to recirculate the exhaust gas to the intake system; an intake air flow rate detecting device detecting air flow rate introduced into the engine; and a controller, when fuel injection is stopped, controlling the engine to start the fuel injection at a rate obtained by adding a first flow rate to a reference flow rate for a stoichiometric air-fuel ratio based on the detected air flow rate when the valve opening degree is lower than a predetermined degree, and controlling the engine to start the fuel injection at a rate obtained by adding a second flow rate, larger than the first flow rate, to the reference flow rate when the valve opening degree is no less than the predetermined degree.

Abstract: An air-fuel ratio imbalance determining apparatus that is configured to sequentially stop a fuel injection for each of cylinders in accordance with a firing (ignition) order by changing the intake valves and exhaust valves of the cylinder whose fuel injection is stopped from a valve operating state to a valve resting state. After a predetermined time elapses (time-point tp), an upstream-side air-fuel ratio value obtained based on an output value of an upstream air-fuel ratio sensor disposed in the exhaust passage which becomes a value corresponding to an air-fuel ratio of the final gas. The determining apparatus obtains that value as data relating to an air-fuel ratio of the cylinder which discharged the final gas, and determines whether or not an air-fuel ratio imbalance is occurring based on the data relating to the air-fuel ratio of each of the cylinders.

Abstract: The invention relates to a suction housing (1) for an internal combustion engine, especially for arranging between a first (2) and a second (3) compressor of an internal combustion engine, characterized in that the suction housing (1) comprises an inner space (8) defined by a bottom element (9), a first (10) and a second (11) opposing lateral wall elements projecting from the bottom element (9), and a first (12) and a second (13) opposing front wall elements projecting from the bottom element. An open end (14) having an inlet (14a) via which charge air can enter the inner space (8) of the suction housing (1) is formed opposite the bottom element (9), and a web element (17) projecting from the bottom element (9) and arranged between the first (10) and the second (11) lateral wall elements is located in the inner chamber, said web element interconnecting the first (12) and the second (13) front wall elements.

Abstract: There is provided a device and a method for decreasing hydrocarbon fuel usage in a vehicle, the method including the steps of installing a fuel treatment device whereby fuel passes through the device prior to going to the engine, the fuel treatment device having an inlet and an outlet, an inner tube having at least one magnet pair with a north pole and a south pole, and an outer tube concentric with the inner tube to thereby form a passageway between the inner tube and the outer tube, a baffle member being mounted in the passageway to cause fuel passing therethrough to flow in a spiral configuration.

Abstract: In view of a difference in detectability of an air-fuel ratio sensor with respect to each cylinder, a first exhaust system model and a second exhaust system model are defined. The first exhaust system model outputs an air-fuel ratio at the confluent portion based on an air-fuel ratio in a cylinder. The second exhaust system model outputs a detection value of the exhaust gas sensor based on the air-fuel ratio at the confluent portion. A confluent-portion-air-fuel ratio estimating portion designed based on the second exhaust system model estimates the air-fuel ratio at the confluent portion. A combust-air-fuel ratio estimating portion designed based on the first exhaust system model estimates a combust-air-fuel ratio in each cylinder.

Abstract: An internal combustion engine includes a cylinder chamber having a cylinder gas inlet and a cylinder gas outlet; an adjustment plate attached to the cylinder gas outlet; an exhaustion pipe attached to the cylinder gas outlet with the adjustment plate in between; and a piston disposed inside the cylinder chamber. The adjustment plate has a through hole having an opening area smaller than that of the air cylinder gas outlet. The adjustment plate is attached to the cylinder gas outlet so that a lower edge of the through hole is situated at a higher position relative to a lower edge of the cylinder gas outlet. The piston is disposed inside the cylinder chamber so that an upper end surface of the piston is situated at a higher position relative to the lower edge of the cylinder gas outlet when the piston is situated at a bottom dead point.

Abstract: Methods and systems are provided for an engine including a humidity sensor. Degradation of the humidity sensor may be determined based on a change in intake air relative humidity as compared to a change in intake air temperature or pressure, under selected conditions. An amount of exhaust gas recirculated to an engine intake is adjusted differently based on whether the humidity sensor is degraded or functional.