Abstract: A fuel injection controller includes an ECU controlling an operation of a fuel injector based on a characteristic data of the fuel injector, an EEPROM provided to the injector, and an EEPROM provided to the ECU. Identification information by which the fuel injector is individually identified is stored in both of the EEPROMs. It is determined whether the identification information stored in the injector-side EEPROM is identical to the identification information stored in the ECU-side EEPROM. Based on this determination result, it can be determined whether the injector and/or the ECU are exchanged to new one.

Abstract: An actual maximum fuel injection rate is computed based on a falling waveform and a rising waveform of the fuel pressure. The falling waveform represents the fuel pressure detected by a fuel sensor during a period in which the fuel pressure increases due to a fuel injection rate decrease. The rising waveform represents the fuel pressure detected by the fuel sensor during a period in which the fuel pressure decreases due to a fuel injection rate increase. The falling waveform and the rising waveform are modeled by modeling functions. A reference pressure is computed based on pressure during a specified time period before the falling waveform is generated. An intersection pressure is computed, at which the straight lines expressed by the modeling functions intersect to each other. The maximum fuel injection rate is computed based on a fuel pressure drop from the reference pressure to the intersection pressure.

Abstract: A fuel injection detecting device computes an actual fuel-injection-start timing based on a falling waveform of the fuel pressure detected by a fuel sensor during a period in which the fuel pressure decreases due to a fuel injection rate increase. The falling waveform is modeled by a modeling formula. A reference pressure is substituted into the modeling formula, whereby a timing is obtained as the fuel-injection-start timing.

Abstract: A fuel injection detecting device computes a maximum-fuel-injection-rate-reach timing and a fuel-injection-rate-decrease-start timing based on a falling waveform of the fuel pressure and a rising waveform of the fuel pressure. The falling waveform represents the fuel pressure detected by a fuel sensor during a period in which the fuel pressure increases due to a fuel injection rate decrease. The rising waveform represents the fuel pressure detected by the fuel sensor during a period in which the fuel pressure decreases due to a fuel injection rate increase. The rising waveform and the falling waveform are respectively modeled by modeling function. In a case of small fuel injection quantity, an intersection timing at which lines expressed by the modeling functions intersect with each other is defined as the maximum-fuel-injection-rate-reach timing and the fuel-injection-rate-decrease-start timing.

Abstract: An intake air quantity correcting device calculates an intake air quantity as a sensing target of an airflow meter (an intake air quantity sensor) based on an injection quantity sensing value sensed with a fuel pressure sensor (an injection quantity sensor) and an oxygen concentration sensing value sensed with an A/F sensor (an oxygen concentration sensor). The intake air quantity correcting device regards a difference between the intake air quantity calculation value calculated in this way and an intake air quantity sensing value sensed with the airflow meter as a sensing error of the airflow meter and corrects the intake air quantity sensing value of the airflow meter based on the sensing error.

Abstract: A fuel injection device includes a fuel injection valve for injecting fuel, which is distributed from a pressure-accumulation vessel. A pressure sensor is located in a fuel passage, which extends from the pressure-accumulation vessel to a nozzle hole, and configured to detect pressure of the fuel. The pressure sensor is located closer to the nozzle hole than the pressure-accumulation vessel. A storage unit stores individual difference information, which indicates an injection characteristic of the fuel injection valve, the injection characteristic being obtained by an examination. The individual difference information is related to a fluctuation pattern of a portion of the fluctuation in detected pressure waveform of the pressure sensor. The fluctuation is attributed to one fuel injection through the nozzle hole. The portion of the fluctuation is subsequent to an end of the fuel injection.

Abstract: A fuel injection control device (ECU) for controlling injection supply of fuel to a target engine has a program for sequentially sensing fuel pressure fluctuating with injection of a predetermined injector a program for detecting an injection centroid of a diagram as a profile of a transition of an injection rate of the injector at a present time based on a transition of the sequentially sensed fuel pressure, and a program for varying an injection command (injection timing) of the injector based on the detected injection centroid and an injection centroid of a predetermined basic diagram such that a relative positional relationship between the injection centroids of the diagram as the actual profile of the injection rate transition and the basic diagram becomes a relationship, in which timings of the injection centroids are close to each other.

Abstract: A cylinder characteristic variation sensing device has a small injection controlling section that performs small injections sequentially in respective cylinders, a torque increase amount sensing section that senses an increase amount of output torque caused in connection with the small injection for each cylinder, an injection quantity sensing section that senses an actual injection quantity of the small injection for each cylinder, and a cylinder characteristic variation calculating section that calculates a variation in a cylinder characteristic among the cylinders (i.e., a cylinder characteristic variation) based on a variation in the sensing value of the injection quantity sensing section among the cylinders (i.e., an injection quantity variation) and a variation in the sensing value of the torque increase amount sensing section among the cylinders (i.e., a torque increase amount variation).

Abstract: A fuel injection system for an internal combustion engine which is designed to determine an instantaneous engine speed in a cycle of, for example, 30° CA of the engine to learn an actual injection quantity that is the quantity of fuel actually sprayed from a fuel injector. The system filters the instantaneous engine speed using a band-pass filter to extract a cyclic component which varies in synchronism with an engine operating cycle to produce an engine speed change which has arisen from the spraying of fuel into the engine from which unwanted noise components are removed and uses it to determine the actual injection quantity.

Abstract: A learning device changes each of multiple parameters to an increased side and to a decreased side with respect to a reference value set for each of the multiple parameters. The learning device calculates an approximation degree for each combination of the changes of the multiple parameters. The learning device performs update by using the combination of the changes providing the highest approximation degree among the approximation degrees as the combination of the updated reference values when an update end condition is not satisfied. The update end condition is a condition that the approximation degree at the reference values is higher than any of the approximation degrees after the change. The learning device decides the reference values as learning values of the multiple parameters when the update end condition is satisfied.

Abstract: A fuel injection system designed to execute a learning operation to spray fuel through a fuel injector in a cycle to calculate an average of actual injection quantities for correcting an injection duration so as to minimize a deviation of the average from a target quantity. The system samples the actual injection quantities for a given period of time made up of a first and a second time section. In each of the first and second time sections, the system decides whether each of the actual injection quantities is suitable for use in calculating the average or not. When a desired number of the actual injection quantities decided to be suitable for the calculation of the average has been derived in the first time section, the system proceeds to the second time section to calculate the average. This enhances the accuracy in determining the quantity of fuel actually sprayed from the fuel injector.

Abstract: A cylinder characteristic variation sensing device has a small injection controlling section that performs small injections sequentially in respective cylinders, a torque increase amount sensing section that senses an increase amount of output torque caused in connection with the small injection for each cylinder, an injection quantity sensing section that senses an actual injection quantity of the small injection for each cylinder, and a cylinder characteristic variation calculating section that calculates a variation in a cylinder characteristic among the cylinders (i.e., a cylinder characteristic variation) based on a variation in the sensing value of the injection quantity sensing section among the cylinders (i.e., an injection quantity variation) and a variation in the sensing value of the torque increase amount sensing section among the cylinders (i.e. a torque increase amount variation).

Abstract: An intake air quantity correcting device calculates an intake air quantity as a sensing target of an airflow meter (an intake air quantity sensor) based on an injection quantity sensing value sensed with a fuel pressure sensor (an injection quantity sensor) and an oxygen concentration sensing value sensed with an A/F sensor (an oxygen concentration sensor). The intake air quantity correcting device regards a difference between the intake air quantity calculation value calculated in this way and an intake air quantity sensing value sensed with the airflow meter as a sensing error of the airflow meter and corrects the intake air quantity sensing value of the airflow meter based on the sensing error.

Abstract: An internal combustion engine control device has a cylinder pressure sensor for sensing pressure in a combustion chamber and a fuel pressure sensor for sensing fuel pressure fluctuating in connection with fuel injection from an injector. The control device calculates a combustion characteristic of a cylinder (for example, an ignition delay or a combustion rate) based on both of a cylinder pressure sensing value and a fuel pressure sensing value. The control device corrects an EGR quantity, supercharging pressure, and injection start timing in accordance with the calculated combustion characteristic. Thus, the control device performs cooperative control of the injection start timing (an injection mode), the supercharging pressure and the EGR quantity (intake air conditions) in accordance with the combustion characteristic of the cylinder.

Abstract: An exhaust gas recirculation distribution variation sensing device has a torque sensing section that senses instantaneous torque caused with combustion of fuel injected from an injector for each cylinder, an injection quantity sensing section that senses an actual injection quantity of the injected fuel for each cylinder and an exhaust gas recirculation distribution variation calculating section that calculates an exhaust gas recirculation distribution variation as a distribution variation of recirculated exhaust gas to respective cylinders based on a variation in the torque sensing value of the torque sensing section among the cylinders (i.e., a torque variation) and a variation in the injection quantity sensing value of the injection quantity sensing section among the cylinders (i.e., an injection quantity variation).

Abstract: A fuel injection device calculates a variation correction value by incorporating in-cylinder pressure into injector individual data based on an injection rate of an injector measured outside a cylinder of an engine. The fuel injection device corrects a target injection amount and generation timing of a command signal of the injector based on the variation correction value. Thus, accurate injection characteristics substantially conforming to designed median values can be obtained inside the cylinder, and highly accurate injection control can be performed. Thus, the fuel injection device can perform accurate multi-injection, which requires extremely high accuracy, to simultaneously achieve reduction of engine vibration and engine noise, purification of exhaust gas and improvement of engine output and fuel consumption at high levels.

Abstract: A common-rail fuel injection system is equipped with a common-rail, a fuel pump 11, and an injector. The fuel pump has a plurality of fuel pumping systems. A pressure sensor is provided at a fuel inlet of the injector. When the fuel pump supplies fuel to each of the fuel pumping systems, an ECU detects a variation in fuel pressure in a fuel passage between the fuel pump and the injector. Based on the detected fuel pressure variation, the ECU computes a pumping characteristic with respect to each of the fuel pumping systems.

Abstract: A variation waveform of fuel pressure is obtained by use of a fuel pressure sensor which detects pressure of fuel supplied to an injector. A quantity of fuel supplied to the injector is estimated based on a waveform of the detected pressure that is greater than a reference value due to a fuel pumping, in the obtained variation waveform. Especially, in a case that the fuel pressure sensor is provided to each of a plurality of injectors, it is desirable to obtain the variation waveform based on the output of the fuel pressure sensor provided to a cylinder in which no fuel injection is currently performed.

Abstract: A pressure sensor is located in a fuel passage, which extends from a pressure-accumulation vessel to a nozzle hole of a fuel injection valve. The pressure sensor is located closer to a nozzle hole than the pressure-accumulation vessel for detecting pressure fluctuated by injection of fuel through the nozzle hole. An instruction signal output unit outputs an injection instruction signal so as to instruct an injection mode of fuel to the fuel injection valve. A defective injection determination unit determines whether a detected pressure of the fuel pressure sensor is fluctuated in a fluctuation mode in a range assumed from the injection instruction signal. The defective injection determination unit determines that a defective injection occurs when determining that the detected pressure is out of the fluctuation mode in the assumed range.

Abstract: An engine control system for managing a schedule of execution of engine control tasks is provided. The system works to schedule execution of the engine control tasks upon receipt of requests to initiate the engine control tasks. The system determines a sequence of execution of the engine control tasks and allocates execution times for which the engine control tasks are to be executed so as to provide chances of execution of the engine control task as evenly as possible. The system may determine required time-sharing ratios of the engine control tasks based on statuses of execution of the engine control tasks.