Abstract: A fuel metering control system for an internal combustion engine having a plurality of cylinders. The system includes an air/fuel ratio sensor and engine operating condition detecting means for detecting engine operating conditions at least including engine speed and engine load. The basic quantity of fuel injection is determined by retrieving mapped data according to the engine speed and engine load. An adaptive controller is provided to calculate a feedback correction coefficient to correct the quantity of basic fuel injection such that the detected air/fuel ratio is brought to a desired value. The desired air/fuel ratio is corrected by a second air/fuel ratio sensor installed downstream of a catalytic converter.

Abstract: A fuel metering control system for an internal combustion engine having a plurality of cylinders. The system includes an air/fuel ratio sensor and engine operating condition detecting device for detecting engine operating conditions at least including engine speed and engine load. The basic quantity of fuel injection is determined by retrieving mapped data predetermined based on an effective opening area of a throttle valve, according to the engine speed and engine load. An adaptive controller is provided to calculate a feedback correction coefficient to correct the quantity of basic fuel injection such that the detected air/fuel ratio is brought to a desired value. The output quantity of fuel injection is further corrected by fuel adhered on an intake manifold wall.

Abstract: A fuel metering control system for an internal combustion engine having a plurality of cylinders. The system includes an air/fuel ratio sensor and engine operating condition detecting means for detecting engine operating conditions at least including engine speed and engine load. The basic quantity of fuel injection is determined by retrieving mapped data according to the engine speed and engine load. An adaptive controller is provided to calculate a first feedback correction coefficient to correct the quantity of basic fuel injection such that the detected air/fuel ratio is brought to a desired air/fuel ratio, and second and third feedback loops are provided for calculating feedback correction coefficients to correct the quantity of fuel injection. The output quantity of fuel injection is determined on the basis of the basic quantity of fuel injection and the feedback correction coefficients.

Abstract: An air-fuel ratio control system for an internal combustion engine has an air-fuel ratio sensor arranged in an exhaust passage of the engine for detecting an air-fuel ratio of exhaust gases emitted from a plurality of cylinders. An output from the air-fuel ratio sensor is sampled whenever the engine rotates through a predetermined crank angle, and sampled values of the output from the air-fuel ratio sensor are sequentially stored. An output characteristic of the air-fuel ratio sensor is detected. One of the sampled values of the output from the air-fuel ratio sensor is selected at least depending on the output characteristic of the air-fuel ratio sensor. An air-fuel ratio of a mixture supplied to each of the cylinders is estimated, separately from other ones of the cylinders, based on selected ones of the sampled values of the output from the air-fuel ratio sensor and a model representative of a behavior of the exhaust passage.

Abstract: A fuel metering control system for an internal combustion engine, having a feedback loop. In the system, the quantity of fuel injection (Tim) to be supplied to the engine (plant) is determined outside of the feedback loop. A first feedback correction coefficient (KSTR) is calculated using an adaptive law, while a second feedback correction coefficient (KLAF), whose control response is inferior to that of the first feedback correction coefficient, is calculated using a PID control law. The feedback correction coefficients are calculated such that the plant output (air/fuel ratio) is brought to a desired value (desired air/fuel ratio). The coefficients are calculated at least in parallel and either of them is selected to be multiplied by the quantity of fuel injection (Ti).

Abstract: There is provided an air-fuel ratio control system for an internal combustion engine installed on an automotive vehicle. The control system controls the air-fuel ratio of a mixture supplied to the engine to a value leaner than a stoichiometric air-fuel ratio immediately after the start of the engine. Operating conditions of the engine and/or operating conditions of the automotive vehicle are detected. Starting of the vehicle is predicted based on the detected operating conditions of the engine and/or the detected operating conditions of the automotive vehicle. The air-fuel ratio of the mixture supplied to the engine is changed to a richer value than the leaner value when the starting of the vehicle is predicted.

Abstract: A fuel supply control system for an internal combustion engine calculates a basic amount of fuel to be supplied to the engine, based on the rotational speed of the engine and load on the engine. An amount of fuel adhering to the inner wall surface of the intake passage of the engine is estimated to calculate an adherent fuel-dependent correction amount. An amount of fuel carried off from the inner wall surface of the intake passage into at least one combustion chamber of the engine is estimated to calculate a carried-off fuel-dependent correction amount.

Abstract: A system for controlling fuel metering for a multi-cylinder internal combustion engine, having a feedback loop which has an adaptive controller and an adaptation mechanism coupled to the adaptive controller for estimating controller parameters .theta.. The adaptive controller calculates a feedback correction coefficient using internal variables that include the controller parameters .theta., to correct a basic quantity of fuel injection obtained by retrieving mapped data by engine speed and engine load, to bring a detected air/fuel ratio to a desired air/fuel ratio. In the system, the internal variables of the adaptive controller are determined in response to detected engine operating conditions, when the engine operation has shifted from an open-loop control region to the feedback control region.

Abstract: A fuel metering control system for an internal combustion engine including a feedback loop having an adaptive controller and an adaptation mechanism that estimates a controller parameters .theta.. The adaptive controller corrects the quantity of fuel injection to bring a controlled variable obtained at least based on an output of said air/fuel ratio sensor, to a desired value. The adaptation mechanism is input with the controlled variable once per prescribed crank angle such as TDC of a certain cylinder and estimates the controller parameters (vector). The adaptive controller is therefore operated to synchronize with every prescribed crank angle, e.g., every TDC of all cylinders of the internal combustion engine. With the arrangement, the system enables adaptive control of a commercially practical internal combustion engine without degrading control performance.

Abstract: An air-fuel ratio control system for an internal combustion engine having at least one catalytic converter arranged in the exhaust passage, comprises an ECU which changes air intake characteristics of the engine, based on operating conditions of the engine, and a plurality of exhaust gas component concentration sensors including at least upstream and downstream exhaust gas component concentration sensors arranged in the exhaust passage at respective locations upstream and downstream of the at least one catalytic converter. The air-fuel ratio of an air-fuel mixture to be supplied to the engine is controlled to a desired air-fuel ratio in a feedback manner responsive to an output from the upstream exhaust gas component concentration sensor. A feedback control parameter for use in the air-fuel ratio feedback control is calculated based on an output from the downstream exhaust gas component concentration sensor.

Abstract: A fuel metering control system for an internal combustion engine having a plurality of cylinders. The system includes an air/fuel ratio sensor and engine operating condition detecting means for detecting engine operating conditions. The basic quantity of fuel injection is determined by retrieving mapped data according to the engine speed and engine load. A controller is provided to calculate a feedback correction coefficient to correct the quantity of basic fuel injection such that variance between individual cylinder air/fuel ratios is decreased. The quantity of fuel injection is further corrected by a fuel adhered to an intake manifold wall.

Abstract: A fuel metering control system for an internal combustion engine having a plurality of cylinders. The system includes an air/fuel ratio sensor and engine operating condition detecting means for detecting engine operating conditions at least including engine speed and engine load. The basic quantity of fuel injection is determined by retrieving mapped data according to the engine speed and engine load. An adaptive controller is provided to calculate a feedback correction coefficient to correct the quantity of basic fuel injection such that the detected air/fuel ratio is brought to a desired air/fuel ratio value is provided for calculating feedback correction coefficients to correct the quantity of fuel injection. The output quantity of fuel injection is determined on the basis of the basic quantity of fuel injection and the feedback correction coefficients, and in addition, fuel adhered on an intake manifold wall.

Abstract: A system for controlling fuel metering for a multi-cylinder internal combustion engine. In the system, a feedback loop having an adaptive controller and an adaptation mechanism coupled to the adaptive controller for estimating controller parameters .theta. is provided. The adaptive controller calculates a feedback correction coefficient using internal variables including the controller parameters .theta., to correct a quantity of fuel injection obtained by retrieving mapped data by engine speed and engine load, to bring a detected air/fuel ratio to a desired air/fuel ratio. The internal variables of the adaptive controller are set such that the feedback correction coefficient is 1.0 or thereabout, when the engine operation has shifted from an open-loop control region to the feedback control region.

Abstract: A system for controlling fuel metering for a multi-cylinder internal combustion engine, having a feedback loop which has an adaptive controller and an adaptation mechanism coupled to the adaptive controller for estimating controller parameters .theta.. The adaptive controller calculates a feedback correction coefficient using internal variables that include at least said controller parameters .theta., to correct a basic quantity of fuel injection obtained by retrieving mapped data by engine speed and engine load, to bring a detected air/fuel ratio to a desired air/fuel ratio. In the system, the internal variables of the adaptive controller are set to predetermined values, when the supply of fuel is resumed after termination of the fuel cutoff, and the adaptive controller calculates the feedback correction coefficient based on the internal variables set to the predetermined value.

Abstract: A fuel metering control system for an internal combustion engine including a feedback loop having an adaptive controller and an adaptation mechanism that estimates controller parameters .theta.. The adaptive controller corrects the quantity of fuel injection to bring a controlled variable obtained at least based on an output of said air/fuel ratio sensor, to a desired value. Estimation error of the controller parameters are defined by an error signal e*. The system is configured such that the signal is compared with a limit value and is replaced to a predetermined value when the calculated estimation error signal exceeds the limit value. Thus, the signal is determined to be a predetermined value.

Abstract: A fuel metering control system for an internal combustion engine including a feedback loop having an adaptive controller and an adaptation mechanism that estimates controller parameters .theta.. The adaptive controller corrects the quantity of fuel injection to bring a controlled variable obtained at least based on an output of said air/fuel ratio sensor, to a desired value. The convergence speed of the controller parameters is determined by a gain matrix that has non-diagonal and diagonal element. The system is configured that the controller parameters are determined without calculating the non-diagonal elements of the gain matrix, or without calculating using the non-diagonal elements of the gain matrix in the determination, decreasing calculation volume.

Abstract: A control system for an internal combustion engine includes a canister for adsorbing evaporative fuel generated in the fuel tank, a purging passage extending between the canister and the intake system, for purging evaporative fuel into the intake system, and a purge control valve for controlling a flow rate of evaporative fuel to be supplied to the intake system through the purging passage. Various sensors detect operating conditions of the engine, and an ECU controls the purge control valve according to detected operating conditions. An amount of fuel to be supplied to the engine is feedback-controlled by calculating a feedback control amount, based on an output from an air-fuel ratio sensor arranged in the exhaust system by using a controller of a recurrence formula type, and the amount of fuel to be supplied to the engine is controlled based on the calculated feedback control amount, such that an air-fuel ratio of an air-fuel mixture supplied to the engine is converged to a desired air-fuel ratio.

Abstract: A fuel metering control system for an internal combustion engine including a feedback loop having an adaptive controller and an adaptation mechanism that estimates controller parameters .theta.. The adaptive controller calculates a feedback correction coefficient that corrects the quantity of fuel injection to bring a controlled variable obtained at least based on an output of an air/fuel ratio sensor, to a desired air/fuel ratio. The convergence speed of the controller parameters are determined by a gain matrix. The gain matrix is determined in response to at least one of the detected engine operating conditions.

Abstract: A fuel metering control system for an internal combustion engine including feedback loop having an adaptive controller and an adaptation mechanism that estimates a controller parameters .theta.. The adaptive controller corrects the quantity of fuel injection to bring a controlled variable at least obtained based on an output of said air/fuel ratio sensor to a desired value. The adaptation mechanism is input with the controlled variable once per prescribed crank angle such as a TDC of a certain cylinder of a four-cylinder engine and estimates the controller parameters (vector) such that the adaptive controller is operated to synchronize with every 4 prescribed crank angle such as every TDC of all cylinders of the internal combustion engine, or with every prescribed crank angle such as every TDC. With the arrangement, the system enables adaptive control of a commercially practical internal combustion engine without degrading control performance.

Abstract: A fuel injection control system for an internal combustion engine calculates an amount of fuel to be injected in a manner carrying out fuel transfer delay-dependent correction based on a delay of transfer of fuel injected from the time the fuel is injected into the intake passage of the engine to the time the fuel is drawn into a corresponding one of an at least one cylinder of the engine, with a predetermined calculating repetition period, and causes fuel injection to be carried out based on a result of the calculation. The amount of fuel to be injected is corrected during execution of the fuel injection based on a newest value of the result of the calculation.