Abstract: In a method for controlling an internal combustion engine by means of interventions in at least one manipulated variable of the internal combustion engine, a setpoint torque or work which is to be performed is determined at the crankshaft of the internal combustion engine, wherein, with respect to a first variable as work which is to be performed or a setpoint torque to be provided, a corresponding setpoint quantity of heat is determined taking into account the instantaneous actual efficiency, with respect to which at least one associated manipulated variable is set in accordance with the value of the set-point quantity of heat, and, for precise setting of the torque, the actual quantity of heat also being sensed, a setpoint efficiency being determined from the actual quantity of heat taking into account work which is to be performed or a setpoint torque which is to be provided, this can correspond to the first variable or to another variable which is formed as a setpoint torque or work which is to be perform

Abstract: The invention is directed to a method and an arrangement for monitoring the operation of a gas flow control element in an internal combustion engine. In this method, the engine rough running is detected and at least one rough-running signal is formed which represents the rough running of the engine. Then, by driving the gas flow control element, a change of the position of the gas flow control element is attempted. Then, a detection of the rough-running signals as a function of the change of the position of the gas flow control element takes place. The change of position is intended by the driving of the gas flow control element. From the above, a function signal can be derived which provides information as to the operation of the gas flow control element. The diagnosis of a gas flow control element by evaluation of the engine rough running in engine controls (which anyway have units for forming rough-running values) permits a diagnosis of the above kind without separate sensors for function monitoring.

Abstract: The startup time of an engine is shortened by performing initial fuel injection after the start of cranking on a cylinder undergoing an intake stroke and a cylinder undergoing an exhaust stroke. After the initial fuel injection, HC emissions are suppressed by performing fuel injection in cylinders undergoing an exhaust stroke. Furthermore when it is determined that initial combustion has not occurred after the initial fuel injection, an additional injection is performed on the cylinder undergoing an intake stroke. In this manner, it is possible to minimize increases in the startup time and adverse effects on exhaust emissions.

Abstract: A method and a device are described for controlling an internal combustion engine. The fuel metering is divisible into at least a first partial injection and a second partial injection. In the second partial injection, a fuel quantity variable, characterizing the fuel quantity injected in the second partial injection, is corrected on the basis of at least one pressure variable, characterizing the fuel pressure, as well as of the fuel quantity variable and at least one further variable.

Abstract: Two embodiments of engine speed control that avoid undesirable vehicle conditions such as wheel slippage or unintentionally performing a wheelie. This is done by sensing actual conditions, which are likely to result in the undesirable vehicle conditions and only changing the engine output when these exact conditions are found. The conditions sensed are the determination of excessive acceleration in engine speed or in the speed of a shaft associated with the engine or the degree of rotational variation or rotational acceleration.

Abstract: A method for controlling fuel delivery from a fuel injector includes determining a first desired engine torque output; determining engine speed; determining a first quantity of fuel to be delivered by the fuel injector based on the first desired engine torque output and the engine speed; determining an injection pressure; and determining a first amount of time for energizing the fuel injector in order to deliver the first quantity of fuel based on the injection pressure. For a system capable of split injection, the method further includes determining a second desired engine torque output; determining a second quantity of fuel to be delivered by the fuel injector based on the second desired engine torque output and the engine speed; and determining a second amount of time for energizing the fuel injector in order to deliver the second quantity of fuel. The method and system of the invention provide more precise control of fuel delivery compared with prior systems and methods.

Abstract: The present invention provides a method and system for determining “engine on” status in a Hybrid Electric Vehicle. A controller determines the engine is necessary and then checks the current “engine on” status. If the engine is not currently running, the controller proceeds to start the engine by commanding the generator to spin or “motor” the engine. The controller then starts fuel flow and spark within the engine to create combustion. A measuring device is then used to determine the crankshaft speed. The controller receives this measurement and determines whether the measured variations in crankshaft speed exceed a calibratable threshold. If the calibratable threshold is exceeded, combustion is determined to be occurring and the engine is on. The controller then turns on the “engine on” status flag.

Abstract: A device for suppressing engine knocks in an internal combustion engine, using a detection device for the detection of the respective operating parameters of the internal combustion engine; a control unit for determining manipulated variables for the injection and ignition on the basis of the acquired operating parameters; a dynamic phase detection device for acquiring a dynamic phase of the internal combustion engine; and a correction device for correcting the manipulated variables for the ignition, which is constructed so that for knock suppression, the ignition control quantity, given a dynamic phase acquired by the dynamic phase detection device, can be adjusted in the late direction by a dynamic lead that is dependent on a predicted load difference, and at the end of the dynamic phase can be brought step-by-step back to the manipulated variable determined by the control unit.

Abstract: A fuel injection control device of an engine having a plurality of cylinders, that prevents sudden change in combustion condition. The control device calculates a basic amount of fuel to be injected into cylinders. The controller then decides an amount of adjustment ultimately made to the basic amount of fuel based on an engine revolution speed difference between the cylinders. The adjustment is stepwise made to the basic amount of fuel so that a total amount of fuel gradually increases or decreases. Since a steep change does not occur in the total amount of fuel, the combustion condition does not change suddenly and the engine does not vibrate.

Abstract: An equivalence ratio-based system for controlling transient engine fueling includes an engine controller responsive to a number of engine operating conditions to estimate a mass of oxygen trapped within a number of cylinders of an internal combustion engine. The engine controller is further operable to map current values of engine speed and commanded fueling to one of a number of predetermined maximum fuel-to-oxygen, or equivalence, ratio values (&PHgr;MAX). The engine controller is then operable to determine an oxygen/fuel control (OFC) limited fueling command (FOFCL) as a function of the estimated oxygen mass value and the maximum equivalence ratio, and to limit engine fueling based on the OFC limited fueling command FOFCL. In one embodiment, the engine controller is operable to fuel the engine according to a minimum of the OFC limited fueling command FOFCL and a default fueling command FDEF, although other fuel limiting strategies are contemplated.

Abstract: The present invention is directed to provide a controller for an internal combustion engine, capable of suppressing deterioration in drivability of an engine. A controller for an internal combustion engine has lean control means for calculating a torque margin from a reference engine speed and an actual engine speed and setting a combustion air-fuel ratio of an internal combustion engine to the lean side on the basis of the torque margin. In addition to correction of a fuel injection amount by the lean control means, the fuel injection amount is further corrected on the basis of a final correction value for reducing deterioration in drivability. The final correction value is set by selecting either a correction value which is set on the basis of an engine speed fluctuation amount or a final correction value of last time, which suppresses deterioration in drivability more. Thus, the operation of setting the air-fuel ratio to the lean side while considering deterioration in drivability can be performed.

Abstract: A device for switching an exhaust gas turbocharger and an exhaust gas turbocharger having such a device are described. The device is used for exhaust gas turbochargers (1) having a variable turbine geometry as well as for other turbochargers (e.g., waste-gate turbochargers) having an (electronically) regulated final controlling element. The exhaust gas turbocharger is switched by a switching signal P from a regulated operation A with a boost pressure regulator (2) to an unregulated operation B with a boost pressure control (3), wherein a delay device (4) is provided for generating the switching signal P with a time delay.

Abstract: A method of operating an internal combustion engine having a variable cam timing mechanism in cooperation with a plurality of deactivatable cylinders and corresponding intake valves includes the steps of scheduling a transition mode of the engine, determining a desired engine torque during the transition mode, determining a VCT phase angle based on the desired engine torque and operating the variable cam timing mechanism in accordance with the VCT phase angle to provide the desired engine torque during the transition mode.

Abstract: The present invention intends to suppress torque variation caused by the change of control parameters (e.g., throttle opening degree, EGR amount, etc.) to be adjusted to maintain stable combustion conditions before and after the switching of combustion mode. To this end, in a homogeneous combustion mode, the indicated torque request is corrected based on a torque efficiency (both air-fuel ratio efficiency and ignition timing efficiency), thereby correcting a target air amount in accordance with the corrected indicated torque request. Furthermore, in a stratified combustion mode, the indicated torque request is corrected based on a torque efficiency (only air-fuel ratio efficiency), thereby correcting a target fuel amount in accordance with the corrected indicated torque request. Furthermore, in the homogeneous combustion mode, it is possible to suppress the torque variation by performing ignition timing correction in addition to the target air amount correction.

Abstract: An inertia-related engine speed fluctuation is computed when the engine is rotated without ignition. A load-related engine speed fluctuation is computed when the engine is rotated with ignition and combustion. The inertia-related engine speed fluctuation is indicative of an inertia moment that is variable in accordance with equipments connected with the engine. The load-related engine speed fluctuation is indicative of an engine load. When estimating the engine load, the inertia-related engine speed fluctuation is considered for removing an influence of the inertia moment on the engine load. The estimated engine load is used for controlling the engine. It is possible to consider the inertia moment into an engine control.

Abstract: An outboard motor comprises an engine mounted within an engine compartment. The engine comprises an induction system having an induction passage extending between a plenum chamber and a combustion chamber. A throttle valve is positioned along the passage. A bypass passage communicates with the passage at a location between the throttle valve and the combustion chamber. An adjustable valve controls flow through the bypass passage. The adjustable valve can be moved below a first preset throttle angle position and fixed above that preset throttle angle. The engine further comprises a fuel injector. The fuel injection amount is controlled by more than one control map. The control maps determine a fuel injection amount based on at least two sensed engine conditions. Based on throttle angle position, the control scheme determines which control map is used.

Abstract: A method for controlling an internal combustion engine determines a desired torque based on an actuating position of an accelerator pedal. A normal fuel quantity based on a given normal efficiency is determined. A relative efficiency is determined based on at least current operating conditions of the internal combustion engine. The normal fuel quantity is corrected based on the relative efficiency in order to determine a fuel quantity which is to be metered to the internal combustion engine. A device for controlling an internal combustion engine is also provided.

Abstract: A system and method for controlling an internal combustion engine with an intake air flow control valve provided downstream of a throttle valve within an intake passage of the internal combustion engine includes controlling an opening amount of the intake air flow valve of the internal combustion engine to adjust the intake air quantity when the intake air quantity cannot be controlled by the throttle valve.

Abstract: A method for phase recognition of an internal combustion engine with a plurality of cylinders is preformed in an operating region of the engine having selected operating conditions. A crankshaft sensor serves to determine the angular position of the crankshaft. A control apparatus evaluates the signals of the crankshaft sensor and triggers injection and ignition impulses depending on the angular position of the crankshaft. The method includes the steps of adopting a phase relationship; changing a &lgr;-value for at least one of the cylinders; injecting at a selected time once or twice per working cycle in each cylinder; detecting speed changes of the internal combustion engine through at least one working cycle; and distinguishing whether the phase relationship of step B is correct or incorrect by the point in time of a rotational speed change or by an absence of rotational speed changes.

Abstract: The invention relates to a method for correcting the input signal of a function by means of which misfire is detected and for synchronizing the cylinders in an internal combustion engine, especially of a vehicle. According to the invention, a control device for correcting the input signal (10) and a control device for synchronizing the cylinders (11) are alternately activated by means of an alternative switching unit (12).

Abstract: In an air fuel ratio control for engines, a target operation characteristic of engine speed is set based on a coolant temperature when the engine starts cranking. The target engine speed is variable with time after the engine cranking has started and converges to a speed value lower than a normal target idle speed. Immediately after a complete combustion of air-fuel mixture suplied to the engine is detected, an actual engine speed is compared with a target engine speed corresponding to the target operation characteristics, and an air-fuel ratio of the mixture supplied to the engine is controlled based on a comparison result.

Abstract: An airplane engine control method and apparatus are provided which form an engine control system easy to operate, which set a reciprocating engine of an airplane in such an operating condition in a partial power mode as to maximize the efficiency of the airframe and the engine as a whole, and which enable setting of suitable partial power in a reciprocating engine with a variable-pitch propeller in such a manner that, when predetermined partial power is set, a relationship expressed by Te ∝ &rgr;N2 is established with respect to the engine torque (Te), the number of engine revolutions (N) and the atmospheric density (&rgr;).

Abstract: Manufacturing imperfections and component failures in the fuel system of an engine, can lead to non-uniform torque production among the cylinders. Non-uniform cylinder torques can be observed as small engine speed fluctuations about the average engine speed at any given operating point. Engine speed data contains fluctuations at different frequencies. The amplitude of fluctuations at some known frequencies tell about the health of the fuel injectors and the engine. In the present invention, the instantaneous engine speed data is filtered by discrete second-order band-pass filters to find the engine speed fluctuations at particular frequencies. The output of the filters is identical to power spectral density of speed signal at those frequencies. The amplitude of each filter output is then compared to a predetermined threshold value. If the amplitude is bigger than this threshold, it indicates the existence of low fueling or high fueling fuel injectors.

Abstract: A fuel control method uses a MAP sensor output that is encoded to render fueling computations insensitive to microprocessor clock accuracy. The signal output of the MAP sensor is encoded as a pulse width modulated signal, the cylinder air mass is calculated as a function of the encoded MAP signal and the engine is fueled according to the calculated cylinder air mass. By using the same time scale to decode the pulse width of the MAP PWM signal as is used to time injector duration, the time scale becomes irrelevant to the actual fuel/air ratio attained.

Abstract: A diagnostic mechanism for processing diagnostic data transferred from a host computer (e.g., a motor vehicle computer) to a portable computer (e.g., a personal digital assistant (PDA), cellular phone, etc.) An alert is provided based on a comparison in the portable computer of a threshold variable (e.g., generated from a desired threshold value input into the portable computer by the user) and a diagnostic variable (e.g., fuel remaining, service interval, etc.) generated from the diagnostic data. Preferably, the alert includes a calendar entry displayed on a PDA. The alert may further include an alarm at a time-of-day preceding an alarm clock setting of the PDA. Consequently, the user does not have to rely on his/her memory to arise earlier in the morning to fill up with gasoline, for example. Preferably, the PDA receives the diagnostic data in response to being placed in a cradle mounted in a vehicle passenger compartment.

Abstract: The invention relates to a method for combustion misfire detection and cylinder equalization in a multi-cylinder internal combustion engine having knock control. In the method, rough-running values are individually determined for each cylinder by measuring segment times with each crankshaft rotation. The segment times include the times corresponding to the piston movement of each cylinder to be measured in which the crankshaft passes through a corresponding circular-segment angular region. Thereafter, the determined rough-running values are compared to a threshold value in a desired value comparison and, on the basis of the deviation between the determined rough-running values and the desired value, cylinder-individual equalization factors (that is, correction factors) are computed in an evaluation unit for the change of injection times or ignition time points of the individual cylinders.

Abstract: A control device for controlling an internal combustion engine with a variably controlled valve stroke and with a butterfly valve in an air intake tract is provided. The control device is equipped with devices with which the even running of the internal combustion engine is monitored and through which the butterfly valve is actuated in the closing direction when a defined uneven running threshold value has been exceeded and when the valve stroke is smaller than a specified threshold until the value drops below the uneven running threshold value again.

Abstract: The invention relates to a method for combustion misfire detection in multi-cylinder internal combustion engines. In the method, rough-running values for each cylinder of the engine are determined individually for each crankshaft rotation by measuring the segment times. The segment times include the times corresponding to the piston movement of each cylinder to be measured during which times the crankshaft passes through a corresponding circular segment angular region and, on the basis of filtered rough-running values, equalization or corrective factors are computed for each cylinder in an evaluation unit for influencing injection times or injection time points of each individual cylinder. The determined rough-running values (LUT) or the filtered rough-running values (FLUT) are compared in a desired value comparison to a threshold value (SW2) which is pregiven in value significantly less than the threshold value (SW1) for misfire detection.

Abstract: An equivalence ratio-based system for controlling transient engine fueling includes an engine controller responsive to a number of engine operating conditions to estimate a mass of oxygen trapped within a number of cylinders of an internal combustion engine. The engine controller is further operable to map current values of engine speed and commanded fueling to one of a number of predetermined maximum fuel-to-oxygen, or equivalence, ratio values (&PHgr;MAX). The engine controller is then operable to determine an oxygen/fuel control (OFC) limited fueling command (FOFCL) as a function of the estimated oxygen mass value and the maximum equivalence ratio, and to limit engine fueling based on the OFC limited fueling command FOFCL. In one embodiment, the engine controller is operable to fuel the engine according to a minimum of the OFC limited fueling command FOFCL and a default fueling command FDEF, although other fuel limiting strategies are contemplated.

Abstract: A system and method for determining control parameters for an engine include modifying a first engine torque based on estimated losses associated with a previously determined desired engine load to determine a second engine torque, modifying the second engine torque based on a desired ignition angle and air/fuel ratio to determine a third engine torque, determining a desired engine load based on the third engine torque, and converting the desired engine load to at least one engine control parameter. The invention recognizes that the transformation between torque and airflow is an affine transformation rather than a linear transformation. The present invention also recognizes the significant interrelations between various engine control parameters such as air/fuel ratio and ignition timing by determining control parameters after the desired torque has been fully compensated for losses and using a single function to account for air/fuel ratio and ignition angle excursions.

Abstract: The invention relates to a method for automatically generating smoothed characteristic diagrams for electronic engine controls of internal combustion piston engines. The invention is characterized in that the adjustment variable combination of the individual successive operating points are input by means of a motor control to a reference internal combustion piston engine by entering specified values of the boundary conditions for the operation of an internal combustion piston engine. According to the invention, the reference internal combustion piston engine is operated in this operating point, and the actual values and/or boundary conditions occurring during the same are acquired and compared with the specified values of the boundary conditions in an optimization system assigned to the engine control and, in the instance of variations, the adjustment variable combinations are optimally altered in a progressive manner by the optimization system.

Abstract: A method and a device for modifying a torque of an internal combustion engine including at least one first cylinder with an exhaust valve including a variable valve control, in which it is determined whether there is a demand for modifying the torque within a first working cycle of the at least one mfirst cylinder, and the basic triggering of the exhaust valve of the first cylinder is modified in the first working cycle when it is determined that it is necessary to modify the torque during the first working cycle.

Abstract: In a system in which an oxygen quantity stored in a catalytic converter is estimated to feedback control a fuel injection quantity based on the estimated oxygen quantity, when a predetermined period of time has not yet passed from an occurrence of misfire and from the end of misfire, the update of the oxygen quantity is suspended, and also, when the predetermined period of time has not yet passed from the end of misfire, the fuel injection quantity is decreasingly corrected and the oxygen quantity is reset after the predetermined period of time has passed.

Abstract: Method of reducing noxious or toxic exhaust emissions from an internal combustion engine (10) having a plurality of cylinders (12) cooperating with a crankshaft (13) to cause the crankshaft to rotate at a rotational speed when the cylinders (12) are provided with an air/fuel mixture having a lambda value and the mixture is ignited to generate pressure in the cylinders. The method includes measuring a parameter reflecting the pressure in a first cylinder during at least a part of a working stroke of the first cylinder when supplied with an air/fuel mixture having a first lambda value to thereby obtain a first parametric value. An air/fuel mixture is provided to a second cylinder, which air/fuel mixture has a second lambda value which is different to the first lambda value, to cause the second cylinder to perform a working stroke. A parameter is measured reflecting the pressure in the second cylinder during at least a part of the working stroke of the second cylinder to obtain a second parametric value.

Abstract: A method of controlling an internal combustion engine is described. The engine is capable of operating in at least two engine operating modes. As an example, the engine can operate in a stratified or a homogeneous combustion mode. The engine operating mode is selected based on a determined atmospheric pressure.

Abstract: A control apparatus for suppressing vibrations of an engine when combustion is stopped. The control apparatus maintains an engine rotational speed at a reference rotational speed for a reference time when the combustion of the engine is automatically stopped. This results in a reduction in pressure in a combustion chamber of the engine. The control apparatus gradually reduces the rotational speed of the crankshaft, and stops the crankshaft before the rotational speed of the crankshaft reaches a resonant speed. In this way, the resonance and increased pressure in the combustion chamber are prevented to reduce vibrations of the vehicle.

Abstract: In a method for controlling an internal combustion engine by means of interventions in at least one manipulated variable of the internal combustion engine, a setpoint torque or work which is to be performed is determined at the crankshaft of the internal combustion engine, wherein, with respect to a first variable as work which is to be performed or a setpoint torque to be provided, a corresponding setpoint quantity of heat is determined taking into account the instantaneous actual efficiency, with respect to which at least one associated manipulated variable is set in accordance with the value of the set-point quantity of heat, and, for precise setting of the torque, the actual quantity of heat also being sensed, a setpoint efficiency being determined from the actual quantity of heat taking into account work which is to be performed or a setpoint torque which is to be provided, this can correspond to the first variable or to another variable which is formed as a setpoint torque or work which is to be perform

Abstract: An improved method and system for the control of an engine system such as the spark timing. The control senses the speed variations either during a portion of a complete cycle and a complete cycle and/or from cycle to cycle in order to determine the load on the engine from preprogrammed maps based upon the engine characteristics. From this load and the speed reading, it is possible to obtain the desired engine control. This not only reduces the costs of the system by reducing the number of sensors, but also permits adjustments to be made more rapidly.

Abstract: When control conditions are satisfied, an A/F value is estimated from an average value of rotation speed Ne and an increasing rotation speed &Dgr;Ne calculated. The estimated A/F value as a base is obtained from the average value of the rotation speed Ne, and a correction value for the estimated A/F value is obtained from the increasing rotation speed &Dgr;Ne. Then, a fuel increment/decrement correction coefficient &ggr; and an air increment/decrement correction coefficient &bgr; are calculated, and used in the control of A/F ratio toward a target A/F value based on a final estimated A/F value.

Abstract: An improved method and system for the control of an engine fuel injection system. The control senses the speed variations either during a portion of a complete cycle and a complete cycle and/or from cycle to cycle in order to determine the load on the engine from preprogrammed maps based upon the engine characteristics. From this load and the speed reading, it is possible to obtain the desired engine fuel injection control. This not only reduces the costs of the system by reducing the number of sensors, but also permits adjustments to be made more rapidly.

Abstract: A method of controlling a direct fuel injection engine is provided. In the method, under a condition where an ignition timing which is accurately detectable is constant, a fuel injection timing is advanced and delayed to measure an average ion current, and the fuel injection timing is controlled so as to maximize the average ion current. Even when the efficiency of a solenoid is lowered to cause a variation of the fuel injection timing, the fuel injection timing can be controlled to be optimized, thus making it possible to maintain an intended efficiency of the direct fuel injection engine over a long period of usage. Particularly, the method can be realized by the use of a conventional ion current detecting device for detection of a misfire, it can be executed with an apparatus which can be attained at low cost. A direct fuel injection engine control system and a storage medium storing the control method of this invention are also provided.

Abstract: This invention is directed to an apparatus and method for providing improved control of fuel, preferably gaseous fuel, to an internal combustion engine such that each cylinder of the engine will operate within a predetermined tolerance off of its lean misfire limit. The disclosed system introduces fuel to the engine at two locations: (1) upstream of the intake manifold to provide premixing of a majority of the fuel with air, and (2) near the intake valve of each cylinder for tailoring the fuel flow to each cylinder to achieve that fuel-to-air ratio which is necessary to maintain each cylinder at the desired tolerance from the lean misfire limit. Several calibration and control methods are described to maximize performance of the fuel system, including the use of a misfire detection technique to determine the lean misfire limit of each cylinder to allow the respective port fuel injector to provide a specified margin from lean misfire.

Abstract: A method of regulating the rotational speed of multicylinder internal combustion engines is described using the rotational speed can be detected precisely and rapidly in a simple and cost-effective manner, permitting stable regulation to a constant rotational speed in the event of periodic and temporary rotational speed fluctuations. The time required for a fixed sequence of successively sensed pulses is continuously measured and used to form equidistant, uncorrected actual rotational speed values. The number of successively sensed pulses is defined as a function of the number of cylinders in the engine and the number of pulses that can be generated by the pole wheel per revolution. The time required for the number of sensed pulses corresponding to one complete revolution of the pole wheel is measured and used to form an average rotational speed. The difference between the average rotational speed and each uncorrected actual rotational speed value is smoothed to form corrected actual rotational speed values.

Abstract: Engine speed and/or vehicle velocity limitation apparatus of engine-driven motor vehicles, wherein a controller defines, as a function of the difference between an actual speed value or actual velocity value as controlled variable, on the one hand, and a speed limit value or velocity limit value or a speed limit function or velocity limit function, on the other hand, a torque setpoint for the engine of the motor vehicle as the manipulated variable. As a result, the combustion processes occur at the stoichiometric ratio even during the limiting operation, and the elimination of torque surges results in a considerable increase in drivability for the driver.

Abstract: When refreshing a catalyst (22) disposed in an exhaust line (20) during operation of a diesel engine (1), diesel engine control increases supercharging pressure by throttling nozzles of a turbocharger (25) so as to increase an amount of air that is charged into a combustion chamber (4) and then opens an exhaust gas recirculation valve (24) and holds it open until a exhaust gas recirculation ratio reaches a specified value. Subsequently, the diesel engine control increases an amount of fuel injection until a mean combustion chamber air-to-fuel ratio reaches a value near a stoichiometric air-to-fuel ratio so as to lower the oxygen concentration of exhaust gas, thereby causing the catalyst (22) to release NOx therefrom and purify the exhaust gas.

Abstract: An engine control unit controls a self-ignition gasoline engine which is capable of changing a combustion condition of the engine between a self-ignition combustion and a spark-ignition combustion according to an engine operating condition. The control unit executes detecting an combustion condition in the engine, detecting a self-ignition limit of a region for executing the self-ignition combustion on the basis of the combustion condition, and varying a combustion parameter for the combustion during the self-ignition combustion so that the combustion condition approaches the self-ignition combustion limit and a self-ignition combustion operation is executed under a condition maintaining the self-ignition limit.

Abstract: Detected first is fluctuation of engine revolution speed that varies with torsional vibration occurring in a drive train when the vehicle is acceleratedldecelerated. A basic amount of fuel injection (Qbase) is determined from an accelerator opening (APS) and engine revolution speed (RPM). An intermediate value (Qbad), which is an amount of fuel needed at the time of drive power being first transmitted to drive wheels from an engine, is determined from water temperature (Tw) and engine revolution speed (RPM). A difference (Qabs) is calculated by subtracting the intermediate value (Qbad) from the basic value (Qbase). A correction value (Qacl2) to counterbalance the fluctuation of the engine revolution speed (RPM) is then determined based on the difference (Qabs), engine revolution speed (RPM), engine revolution speed change (&Dgr;RPM) and/or its differential value (D&Dgr;RPM).

Abstract: A fuel injection control device of an engine having a plurality of cylinders, that prevents sudden change in combustion condition. The control device calculates a basic amount of fuel to be injected into cylinders. The controller then decides an amount of adjustment ultimately made to the basic amount of fuel based on an engine revolution speed difference between the cylinders. The adjustment is stepwise made to the basic amount of fuel so that a total amount of fuel gradually increases or decreases. Since a steep change does not occur in the total amount of fuel, the combustion condition does not change suddenly and the engine does not vibrate.

Abstract: A control method for controlling the operation of a compression ignition internal combustion engine comprising the steps of measuring the change in the engine speed which occurs during a period leading up to substantially the top-dead-center position of a cylinder of the engine, using the measured engine speed change in a delta speed change algorithm, and using the output of the delta speed change algorithm to derive a pilot fuel correction factor. The pilot fuel correction factor may be derived using a fuel balancing or correction algorithm. The method may also be used in conjunction with a fuel balancing algorithm for correcting or balancing the fuel quantities delivered in the main injections.

Abstract: A diagnosing system for an engine diagnoses malfunctions that occur in a direct-injection engine in which fuel is injected into combustion chambers or a lean-burn engine. The present invention provides a diagnosing system for an engine capable of diagnosing malfunctions in an intake air flow intensifying component and a fuel supply component and of specifying a malfunctioning part without being affected by the difference between different engines, the difference in quality between parts and aging.