Abstract: A compression ignition engine (60) has a control system (66) for processing data, one or more combustion chambers (62), and fuel injectors (64) for injecting fuel into the chambers. The control system controls fueling by processing engine speed and load, to select one of four fueling modes (HCCI+RVT, HCCI+IVC, HCCI+IVC+EVC, and CD+RVT) for operating the engine (FIG. 5). When HCCI+RVT mode is selected, intake valves operate with regular valve timing (RVT), and the engine is fueled to cause homogeneous-charge compression-ignition (HCCI) combustion. When HCCI+IVC mode or HCCI+IVC+EVC mode is selected, intake valve timing is changed relative to RVT, and the engine is fueled to cause HCCI combustion. When the processing selects the CD+RVT mode, the intake valves operate with RVT, and the engine is fueled to cause CD combustion. In HCCI+IVC+EVC mode, exhaust valve closing is retarded relative to its timing in HCCI+IVC mode to reduce cylinder pressure and temperature.

Abstract: Method of smoke limiting an engine. The method may include determining a minimum air/fuel (AFR) ratio and fuel limiting as a function thereof. The method may include determining a maximum fueling rate as a function of the minimum AFR and air mass flow to the engine. The method may include controlling the engine according to a requested fueling rate unless the requested fueling rate is greater than the maximum allowable fueling rate.

Abstract: An emission control device for use with stationary or mobile gas-fueled internal combustion engines is described, which is placed in the fuel supply line and operates with full fuel authority. An oxygen sensor measures exhaust oxygen content. The valve internally houses a programmable microprocessor, a pressure transducer and a fuel flow conduit throttled by a balanced poppet valve. Signals to the microprocessor from the oxygen sensor, the pressure transducer indicating outflow gas pressure cause the microprocessor to motivate an actuator to move the valve within the gas stream and thus regulate the outlet pressure and also the gas flow rate to maintain a desired air/fuel ratio to the engine and keep exhaust emissions at an optimum level consistent with the engine operating load requirements and characteristics. Finite incremental control of valve position, preferably assisted by an internal position transducer, permits close control of the exhaust emissions.

Abstract: In a low rotation speed and low load operation region of an internal combustion engine, the heating of an air-fuel ratio sensor by a heater is stopped, and also an air-fuel ratio feedback control is stopped, and just after the heating of the air-fuel ratio sensor by the heater and the air-fuel ratio feedback control are started, a smoothing degree of a detection signal of the air-fuel ratio sensor is set to be small, to perform the air-fuel ratio feedback control based on the smoothed detection signal.

Abstract: A vehicle control system regulates oxides of nitrogen levels in vehicle emissions. Recirculation of exhaust gas in an engine is controlled with an exhaust gas regulator valve and/or a cam phaser. An oxides of nitrogen sensor determines the level of oxides of nitrogen levels in the exhaust gas and communicates the information to a vehicle controller. The controller determines if the oxides of nitrogen levels are within a predetermined threshold according to a lookup table. The controller adjusts the valve and/or cam phaser if the oxides of nitrogen levels are not within the threshold.

Abstract: In a method for operating a diesel engine and a diesel engine, wherein engine emission control is provided by switching between a lean mode with superstoichiometric combustion air ratio ?>1 and a rich mode with substoichiometric combustion air ratio ?<1, the engine-torque fluctuations during the switching are determined and engine parameters which influence the engine torque, are adjusted so as to keep the engine torque constant during the switchover.

Abstract: An engine control system for monitoring torque increase during cylinder deactivation for a displacement on demand (DOD) engine includes a throttle and a controller. The controller adjusts a preload of the throttle prior to a cylinder deactivation event and determines whether a DOD fault is present during the cylinder deactivation event. The controller one of operates the engine without the preload in the deactivated mode and switches the engine back to the activated mode if the fault is present for a predetermined time. The controller cancels the preload if the DOD fault is present and resets the preload if the predetermined period has not expired. The DOD fault includes one of an engine speed fault, a transmission gear fault and a fueled cylinder fault.

Abstract: The invention relates to an internal combustion engine comprising a fuel injector (2) for each cylinder; a fuel injection control unit (4) for controlling fuel injection quantity and a piston (5) in each cylinder whose compression action causes a mixture of air and fuel to be ignited. The engine is further provided with inlet and outlet valves (6, 7) and various sensors (12-16) for measuring various engine operating parameters. During compression ignition mode, the control unit (4) is arranged to select a ?-value from a map stored in the control unit, which value is a function of engine load and engine speed, and to compare the actual ?-value with the selected ?-value; whereby the control unit is arranged to adjust the intake manifold pressure as a function of the difference between the said ?-values in order to obtain the selected ?-value. The invention further relates to a method for operating the engine and a computer readable storage device (4).

Abstract: A system for improving the performance of a motor vehicle internal combustion engine includes a controller positioned between an O2 sensor. The controller alters the O2 sensor signals and adjusts supplemental sensor signals received from supplemental sensors and sends the altered O2 signals and the adjusted supplemental sensor signals to a programmed electronic control unit which controls operation of fuel injectors.

Abstract: An engine control system that identifies fuel dynamical steady state (FDSS) includes a cylinder and a controller that determines a detection period. The controller monitors a mass of fuel ingested by the cylinder during the detection period. The controller identifies FDSS if the mass of fuel remains within a predetermined range during the detection period.

Abstract: There is provided a control system for an internal combustion engine, which is capable of meeting a driver's demand of torque, and achieving high combustion efficiency and high emission-reducing performance by a three-way catalyst in lean-burn operation in a compatible manner. The control system sets a control amount indicative of either an oxygen mass supplied to a combustion chamber or a fuel injection amount such that oxygen concentration in exhaust gases becomes equal to a value corresponding to stoichiometric combustion. A target value corresponding to a demanded torque is set based on detected engine operating conditions. A degree of opening of a main throttle valve and a degree of opening of a sub-throttle valve in a passage by passing an intake passage equipped with a nitrogen-enriching device are controlled such that the control amount becomes equal to the set target value.

Abstract: A control system for a plant, having an identifier and a controller. The identifier identifies model parameters of a controlled object model which is obtained by modeling the plant. The controller calculates a control input to the plant so that an output from the plant coincides with a control target value, using the identified model parameters. The controller calculates a self-tuning control input, using the model parameters identified by the identifier. The controller further calculates a damping control input according to the rate of change in the output from the plant or the rate of change in a deviation between the output from the plant and the control target value. The controller calculates the control input to the plant as a sum of the self-tuning control input and the damping control input.

Abstract: A method for forming an actuating variable to be output periodically by a control unit in output periods for controlling an apparatus, in particular the ignition or fuel injection of internal combustion engines, includes reading output signals of at least two sensors into the control unit and ascertaining individual components of the actuating variable based on the output signals. The sensor output signals are read-in and the individual components are determined periodically at intervals of one read-in period or one determination period being equal to or a multiple of the output period of the actuating variable. The read-in period of a sensor output signal is dependent on a speed of variation of the sensor output signal, and in particular it increases as the maximum speed of variation of the sensor output signal decreases. The determination period of each individual component is dependent on the read-in periods of the sensor output signals involved in each individual component.

Abstract: An air-fuel ratio detected by an air-fuel ratio sensor is estimated based on an estimation value of air-fuel ratio of an air-fuel mixture formed inside a cylinder, and based on an air-fuel ratio estimated as being detected by this air-fuel ratio sensor and the air-fuel ratio detected based on an output signal of the air-fuel ratio sensor, the estimation value of the cylinder air-fuel ratio is corrected and a fuel injection quantity is corrected based on the corrected cylinder air-fuel ratio.

Abstract: A basic target excess air factor tLAMBDA0 and a target fresh air intake amount tQac are set base upon the operation condition of an engine (30). A target excess air factor tLAMBDA is calculated by multiplying the ratio of a real fresh air intake amount rQac as detected by a sensor (16) and the target fresh air intake amount tQac by the basic target excess air factor tLAMBDA0. A fuel injector (9) is controlled so that the amount of fuel injected thereby converges to a target fuel injection amount tQf which corresponds to the target excess air factor tLAMBDA. It is possible to prevent variation of the output torque of the engine (30) accompanying a rich spike by this control, even if the basic target excess air factor tLAMBDA0 varies abruptly, since the fuel injection amount varies in correspondence to the variation of the real fresh air intake amount rQac.

Abstract: An internal combustion engine including a combustion chamber, an intake air passage communicated with the combustion chamber, an intake valve having a thermal insulator at an air-exposure portion thereof which is opposed to the intake air passage, a fuel injector disposed within the intake air passage and operative to inject an amount of fuel toward the air-exposure portion of the intake valve at a fuel injection timing, and a controller in communication with the fuel injector. The controller is programmed to set the fuel injection timing of the fuel injector to an engine intake stroke.

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 air-fuel ratio control system for an internal combustion engine is comprised of an engine condition detecting unit and a control unit. The control unit is arranged to calculate a target engine torque on the basis of an engine operating condition, to calculate a target EGR ratio, a target excess air ratio and a target intake air quantity on the basis of the engine operating condition and the target engine torque, to calculate a target equivalence ratio on the basis of the target EGR ratio and the target excess air ratio, to calculate a target injection quantity on the basis of the engine operating condition and the target equivalence ratio, and to control an air-fuel ratio by bringing a real intake air quantity to the target intake air quantity and by bringing a real fuel injection quantity to the target fuel injection quantity.

Abstract: A device for controlling an internal combustion engine having an arrangement for recording operating parameters of the internal combustion engine, such as engine speed, load, and coolant temperature; an arrangement for providing a signal related to a desired drive torque of the internal combustion engine (engine torque) as a function of the recorded performance quantities; and an arrangement for converting the engine torque into control signals for at least one of the variables air supply or fuel supply to the internal combustion engine, as a function of the coolant temperature toot and of a pre definable maximum allowable coolant temperature limit tom-tom, a torque control value being determined which ultimately determines the allowable engine torque.

Abstract: The invention provides a fuel control method and system for an internal combustion engine. The method includes: calculating an initial amount of fuel based on an amount of intake air, calculating a first cylinder bank air/fuel ratio matching coefficient and a second cylinder bank air/fuel ratio matching coefficient based on an engine speed and a volumetric efficiency, and controlling the amounts of fuel in the second and first banks, using the calculated second bank air/fuel ratio matching coefficient and the first bank air/fuel ratio matching coefficient, respectively. The system includes a control unit and a fuel injection system for implementing the method.

Abstract: A method for controlling the titre of the exhaust gases in an internal combustion engine. An oxygen sensor provides a signal indicative of a titre (lambda) of the exhaust gases. The method includes selecting respective values of operating parameters on the basis of an objective lambda value and engine-related parameters, calculating a correction parameter on the basis of the respective values of the operating parameters and the lambda signal and calculating an adjustment quantity of fuel on the basis of the correction parameter and a nominal quantity of fuel. The method further includes selecting respective values of a first and a second of the operating parameters, determining magnitudes as a function of the respective values of the first and the second operating parameters and determining a third of the operating parameters as a function of the first and the second operating parameters and a mean value of the correction parameter.

Abstract: A method for controlling mode transitions, such as from stratified to homogeneous mode, in a direct injection engine adjusts an intake manifold outlet control device, such as a cam timing, to rapidly control cylinder fresh charge despite manifold dynamics. In addition, a coordinated change between an intake manifold inlet control device, for example a throttle, and the outlet control device is used to achieve the rapid cylinder fresh charge control. In this way, engine torque disturbances during the mode transition are eliminated, even when cylinder air/fuel ratio is changed from one cylinder event to the next.

Abstract: A method for controlling mode transitions, such as from stratified to homogeneous mode, in a direct injection engine adjusts an intake manifold outlet control device, such as a cam timing, to rapidly control cylinder fresh charge despite manifold dynamics. In addition, a coordinated change between an intake manifold inlet control device, for example a throttle, and the outlet control device is used to achieve the rapid cylinder fresh charge control. In this way, engine torque disturbances during the mode transition are eliminated, even when cylinder air/fuel ratio is changed from one cylinder event to the next.

Abstract: A method is provided for controlling an engine having an intake manifold and an outlet control device coupled to the manifold for controlling flow exiting the manifold and entering at least one cylinder of the engine. The engine further includes an inlet control device for controlling flow entering the manifold. The method includes providing an engine command; calculating a desired cylinder charge based on said command; and adjusting the outlet control device to provide said desired cylinder charge. The engine command may be, for example, a driver command, such as a driver torque command. Further, the outlet control device may be implement in with a variety of mechanisms. For example, in one embodiment the outlet control device is a valve of the engine having a variable lift. In one embodiment the outlet device is a valve having variable timing. Likewise, the inlet device may be adjusted in response to a variety of parameters.

Abstract: An internal combustion engine including a combustion chamber, an intake air passage communicated with the combustion chamber, an intake valve having a thermal insulator at an air-exposure portion thereof which is opposed to the intake air passage, a fuel injector disposed within the intake air passage and operative to inject an amount of fuel toward the air-exposure portion of the intake valve at a fuel injection timing, and a controller in communication with the fuel injector. The controller is programmed to set the fuel injection timing of the fuel injector to an engine intake stroke.

Abstract: A non-linear term UNL is computed as UNL=gain GNL×(air-fuel ratio detection value−target air-fuel ratio)/(|air-fuel ratio detection value−target air-fuel ratio|)+previous value UNL (OLD), and a linear term UL is computed as UL=gain GL×(air-fuel ratio detection value−target air-fuel ratio)/air-fuel ratio detection value. An addition of UNL and UL is set as an air-fuel ratio feedback correction coefficient to correct a fuel injection quantity. The gain GL is set a greater value as |air-fuel ratio detection value−target air-fuel ratio| becomes greater.

Abstract: An air-fuel ratio feedback control of an internal combustion engine is performed, by a sliding mode control, by computing an air-fuel ratio feedback control amount including a linear term and a nonlinear term, and at the time of when switching a target air-fuel ratio or at the time of when switching the operating condition, such as the cutting of purge, where the air-fuel ratio is changed, the nonlinear term is initializing to a predetermined value corresponding to the post-switched operating condition.

Abstract: In an air-fuel ratio feedback control of an internal combustion engine aimed to approximate an air-fuel ratio to a target air-fuel ratio set according to operating conditions of the engine, the feedback control is carried out using the feedback control amount which is computed according to a sliding mode control, having a deviation between the target air-fuel ratio and the detected air-fuel ratio detected by the air-fuel ratio sensor set as a switching function. According to the present invention, a simple air-fuel ratio feedback control is carried out according to an accurate sliding mode control with no dispersion for each engine, that is easy to design, and that can be applied generally to any kind of vehicle or engine.

Abstract: In a sliding mode control for restraining an air-fuel ratio state on a switching line set on a phase plane shown by a deviation between an actual air-fuel ratio and a target air fuel ratio, and a differential value of the deviation, an inclination of the switching line is made small, when the smaller an intake air quantity is, the longer a detection delay time of the air-fuel ratio is.

Abstract: This invention is a method and system for a hybrid electric vehicle adaptive fuel strategy to quickly mature an adaptive fuel table. The strategy adaptively alters the amount of fuel delivered to an internal combustion engine to optimize engine efficiency and emissions using engine sensors. Before the adaptive fuel strategy is permitted, an engine “on” idle arbitration logic requires the HEV to be in idle conditions, with normal battery state of charge, normal vacuum in the climate control and brake system reservoir; and, the vapor canister not needing purging. The strategy orders the engine throttle to sweep different airflow regions of the engine to adapt cells within the adaptive fuel table. In the preferred configuration, a generator attached to the vehicle drive train, adds and subtracts torque to maintain constant engine speed during the throttle sweeps.

Abstract: A circuit for improving the resolution of an oxygen sensor in a vehicle exhaust system. The circuit expands a limited output voltage range of an oxygen sensor to full voltage range of an analog-to-digital (A/D) converter, prior to input of the expanded signal into the A/D converter. Utilization of the full range of converter provides improved resolution for analyzing the analog signal.

Abstract: An air-fuel ratio detected by an air-fuel ratio sensor is estimated based on an estimation value of air-fuel ratio of an air-fuel mixture formed inside a cylinder, and based on an air-fuel ratio estimated as being detected by this air-fuel ratio sensor and the air-fuel ratio detected based on an output signal of the air-fuel ratio sensor, the estimation value of the cylinder air-fuel ratio is corrected and a fuel injection quantity is corrected based on the corrected cylinder air-fuel ratio.

Abstract: In an air-fuel ratio feedback control system for engines, a feedback correction amount is calculated in response to an air-fuel ratio detected at an engine exhaust side to effect an air-fuel ratio feedback control even during an engine warm-up period. A delay time compensation amount is calculated from two basic fuel injection amounts calculated presently and previously. The previous fuel injection amount is calculated the delay time before the present fuel injection amount. The feedback correction amount is corrected with the delay time compensation amount. When the engine undergoes a transient operation condition such as acceleration or deceleration, the present fuel injection amount is corrected with the corrected feedback correction amount. When the basic fuel injection amount changes rapidly due to acceleration, the delay time compensation amount is decreased responsively and the corrected feedback correction amount is increased so that the present fuel injection amount is not reduced too much.

Abstract: An air-fuel ratio control apparatus performs an intake air-increasing process based on a region of an air-fuel ratio feedback adjustment coefficient FAF in which the adjustment coefficient decreases the fuel concentration in an air-fuel mixture. The apparatus calculates a fuel injection valve open duration TAU by using a newly calculated air-fuel ratio feedback adjustment coefficient FAFx, instead of using an adjustment coefficient FAF. An air-fuel ratio-increasing feedback adjustment coefficient FVLV in the adjustment coefficient FAFx has a value that cancels an increase in the amount of intake air. Therefore, the fuel injection amount is increased only when the fuel concentration in the mixture is an intake air-increasing process. Hence, torque difference between fuel concentration-increasing and concentration-decreasing control becomes smaller.

Abstract: A method and system is provided for improving the adjustment of fuel levels delivered to an internal combustion engine. A controller 15 calculates commanded air-fuel levels to deliver to the engine 13 based on a plurality of control signals, including air-fuel ratio signals measured by an air-fuel sensor 54 in the exhaust stream downstream of the engine 13. Systematic errors that reduce the accuracy of the commanded air-fuel level, including systematic errors associated with air-fuel ratio measurements, are identified and compensated for according to the present invention. Statistical methods and known operational characteristics of the air-fuel sensor are used to attribute a portion of the total system fuel error to air-fuel ratio measurement errors and such errors are compensated for to permit the calculation of a more accurate commanded air-fuel level.

Abstract: An air-fuel ratio feedback control of an internal combustion engine is performed, by a sliding mode control, by computing an air-fuel ratio feedback control amount including a linear term and a nonlinear term, and at the time of when switching a target air-fuel ratio or at the time of when switching the operating condition, such as the cutting of purge, where the air-fuel ratio is changed, the nonlinear term is initialized to a predetermined value corresponding to the post-switched operating condition.

Abstract: In a sliding mode control for restraining an air-fuel ratio state on a switching line set on a phase plane shown by a deviation between an actual air-fuel ratio and a target air fuel ratio, and a differential value of the deviation, an inclination of the switching line is made small, when the smaller an intake air quantity is, the longer a detection delay time of the air-fuel ratio is.

Abstract: A method for controlling mode transitions, such as from stratified to homogeneous mode, in a direct injection engine adjusts an intake manifold outlet control device, such as a cam timing, to rapidly control cylinder fresh charge despite manifold dynamics. In addition, a coordinated change between an intake manifold inlet control device, for example a throttle, and the outlet control device is used to achieve the rapid cylinder fresh charge control. In this way, engine torque disturbances during the mode transition are eliminated, even when cylinder air/fuel ratio is changed from one cylinder event to the next.

Abstract: A device for controlling an internal combustion engine having an arrangement for recording operating parameters of the internal combustion engine, such as engine speed, load, and coolant temperature; an arrangement for providing a signal related to a desired drive torque of the internal combustion engine (engine torque) as a function of the recorded performance quantities; and an arrangement for converting the engine torque into control signals for at least one of the variables air supply or fuel supply to the internal combustion engine, as a function of the coolant temperature tmot and of a predefinable maximum allowable coolant temperature limit tmotmax, a torque control value being determined which ultimately determines the allowable engine torque.

Abstract: A method of minimizing torque disturbances in an internal combustion engine for a vehicle having a lean NOx trap that is periodically purged. The method includes the steps of generating feedforward values of first engine characteristics as a function of desired engine torque and generating feedback values of second engine characteristics as a function of intake manifold pressure. Target values are then calculated for predetermined engine variables based on the first and second engine characteristics. Engine variables are then set to the target values to compensate for torque disturbances resulting from the lean NOx trap purge cycle. According to the disclosed method, the feedforward path schedules the throttle, fuel rate and spark timing based on an engine model to produce a demanded engine torque. The feedback path then uses the values of fuel rate and spark timing to compensate for torque variations.

Abstract: Process for controlling an internal combustion engine equipped with an exhaust gas recirculation device (5) comprising a recirculation valve (51) and a device for regulating an air/fuel mixture injected into an inlet circuit as a function of the signal (LAM_AV) of an oxygen probe (41) placed in the exhaust circuit (4), characterized in that the controls of the valve (EGR_CTRL) are synchronized with at least one transition of a correction (LAM_COR) of the richness of the mixture in order to reduce the transient pollution peaks generated by the operating of the exhaust gas recirculation valve (51).

Abstract: A basic cylinder-charged air quantity is determined by a first-order delay processing of an intake air quantity per rotation. Next, an estimated value of a change portion of the cylinder-charged air quantity caused by a change in intake valve timing is computed on the basis of engine speed, throttle opening angle, displacement angle of the intake valve timing. Then, the estimated value of the change portion of the cylinder-charged air quantity is processed second-time by the first-order delay. A difference between the estimated value of a change portion of the cylinder-charged air quantity and a value obtained by processing the estimated value second-time by the first-order delay is added as a delay correction to the basic cylinder-charged air quantity, thereby obtaining an actual cylinder-charged air quantity with a change in the intake valve timing.

Abstract: A method of controlling a internal combustion engine assembly is disclosed. The internal combustion engine assembly includes (i) a internal combustion engine having an engine inlet and an engine outlet, (ii) a mixing chamber having an air inlet, a gaseous fuel inlet, and a fuel-air mixture outlet, (iii) a fuel valve which controls a ratio of air-to-gaseous fuel in a fuel-air mixture advanced through the fuel-air mixture outlet of the mixing chamber, and (iv) a throttle operable to control flow rate of the fuel-air mixture which is advanced from the fuel-air mixture outlet to the engine inlet. The method includes the step of determining oxygen content of exhaust gases advanced through the engine outlet and generating a oxygen content signal in response thereto. The method further includes the step of determining a load on the internal combustion engine and generating a load signal in response thereto.

Abstract: An air/fuel ratio control method for an internal combustion engine corrects airflow prediction errors. The method compares the current airflow to the value that was predicted several events in the past and creates an error signal. Based on this error signal, the current fueling is adjusted. These two mixtures, with equally offsetting lean and rich air/fuel ratios allow the catalytic converter to operate at peak efficiency despite prediction errors.

Abstract: A continuous flow fuel system includes an oxygen sensor for analyzing the exhaust gases of an engine. The output from the oxygen sensor, representing the oxygen content in the exhaust gases, is transmitted to an electronic control module, which in turn controls the output of a fuel pump. The output of the fuel pump provides fuel to maintain a desired fuel/air ratio. The desired fuel/air ratio may be selected by a user of the engine or it may be predetermined and factory-set.

Abstract: An air/ratio control system and method for an internal combustion engine coupled to a fuel vapor recovery system simultaneously maps a difference between a desired air/fuel ratio and a measured air/fuel ratio to fueling errors and a purge vapor flow. This system and method maximizes the ability to purge the vapor recovery system while maintaining the ability to diagnose fuel errors.

Abstract: A true closed-loop air/fuel ratio control system for an internal combustion engine which uses a cylinder air charge percentage value also known as a cylinder or engine load value, is used to control the air/fuel ratio of said engine in response to the difference of said measured load value and a predetermined optimum load value. This process allows true closed-loop fuel control immediately following a cold or warm engine start without need of a traditional exhaust gas sensor. As this process automatically compensates for all fuel utilized by the engine, even during cold starting and idles, the problems associated with fuel vapor purge systems are eliminated. This process can reduce government regulated emissions from said engine considerably and improve fuel economy a significant percentage particularly when operated net lean of stoichiometric. Elimination of currently required engine hardware for traditional systems can allow for a considerable cost savings.

Abstract: The apparatus for correcting air-flow sensor output includes an air-flow sensor sensing an air-flow in an intake of an engine, and other sensors sensing operating conditions of the engine. An electronic control unit determines whether the engine is operating in one of a first and second state based on the sensed operating conditions, and reads a correction factor from a data map based on the sensed operating conditions when the engine is operating in the first state. Also, the electronic control unit calculates a new correction factor based on the sensed operating conditions and stores the new correction factor in the data map when the engine is operating in the second state. Then, the electronic control unit determines a corrected air-flow quantity based on the sensed air-flow and one of the read correction factor and the calculated correction factor.

Abstract: A fuel delivery control system suitable for use with internal combustion engines fueled by liquid propane gas or the like. A stepper motor actuated control valve 52, under the control of a closed-loop fuel control logic routine, meters the desired fuel delivery rate. The stepper motor 50 is initially positioned based on an open-loop value related to the given engine speed and load. The stepper motor position is thereafter controlled by a calibrateable function having engine speed as its input.

Abstract: The invention is directed to a method for computing a fuel-metering signal for adjusting a pregiven lambda value for the composition of the air/fuel mixture of an internal combustion engine. In the method, a first signal is formed which represents the air quantity flowing into the engine and a second signal is formed on the basis of the first signal so that a first lambda desired value adjusts when using its second signal as a fuel-metering signal. Various additional second lambda desired values are formed as a function of operating parameters of the engine. A selection is made of those second lambda desired values having the highest priority and the fuel-metering signal is formed by weighting the second signal with the second lambda desired value of the highest priority.