Abstract: A defective-portion detector has a detecting portion which detects a variation in fuel pressure as a fuel pressure waveform based on a detection value of a fuel pressure sensor and a computing portion which computes, based on the fuel pressure waveform, a plurality of injection-rate parameters required for identifying an injection-rate waveform corresponding to the fuel pressure waveform. Further, the detector has a determining portion which determines whether each learning value of the injection-rate parameters is an abnormal value and an identifying portion which identifies a defective portion in the fuel injection system based on a combination of abnormal learning values which the determining portion has determined.

Abstract: A fuel-injection condition detector includes a first approximate portion which approximates a plurality of fuel pressure values representing the descent pressure waveform or the ascent pressure waveform into a least-squares approximate line by least-squares method; and a weighting portion which applies a weight to the fuel pressure value. The weight is set greater as a difference between the fuel pressure and the least-squares approximate line is larger. Then, the weighted values are approximated into a weighted approximate line by the least-squares method.

Abstract: An engine control apparatus which may be employed in automotive vehicles. The engine control apparatus is equipped with a controlled variable arithmetic expression which defines correlations between a plurality of combustion parameters and a plurality of controlled variables of actuators for control of an operation of the engine to calculate a combination of command values to be outputted to the actuators for regulating the controlled variables needed to achieve target values of the combustion parameters. When one of the command values is produced outside an allowable operation range of a corresponding one of the actuators, the engine control apparatus corrects or limits the one of the command values to an upper or a lower limit of the allowable operation range, thereby ensuring the stability in bringing engine output characteristics close to desired values.

Abstract: An engine control apparatus which may be employed in automotive vehicles. The engine control apparatus is equipped with at least one of a combustion parameter or a controlled variable arithmetic expression. The combustion parameter arithmetic expression defines combustion conditions of the engine needed to achieve required values of engine output-related values such as exhaust emissions. The controlled variable arithmetic expression defines how to operate actuators for an operation of the engine to meet desired combustion conditions of the engine. The use of the combustion parameter or controlled variable arithmetic expression achieves simultaneous agreement of the engine output-related values with required values without mutual interference between combustion parameters associated with the combustion conditions.

Abstract: An apparatus of estimating fuel injection state of a fuel injection system have at least three injectors. The first and second injectors have fuel pressure sensors respectively. The third injector has no fuel pressure sensor. The apparatus detects an injected cylinder waveform to the first injector when the first injector injects fuel. The apparatus detects a first non-injected cylinder waveform to the second injector when the first injector injects fuel. The apparatus calculates correlations between the injected cylinder waveform and the first non-injected cylinder waveform. The apparatus acquires a second non-injected cylinder waveform detected by the first or second fuel pressure sensor when the third injector injects fuel. The apparatus estimates fuel injection state injected from the third injector based on the second non-injected cylinder waveform and the correlations.

Abstract: An engine control apparatus which may be employed in automotive vehicles. The engine control apparatus is equipped with a controlled variable arithmetic expression which defines correlations between combustion parameters associated with combustion conditions of an engine and controlled variables actuators for an operation of the engine. This eliminates the need for finding relations of optimum values of the controlled variables to the combustion parameters through adaptability tests, which results in a decrease in burden of an adaptability test work and a map-making work on manufacturers. The engine control apparatus also works to learn or optimize the controlled variable arithmetic expression based on actual values of the combustion parameters, thereby avoiding undesirable changes in correlations, as defined by the controlled variable arithmetic expression, due to a change in environmental condition.

Abstract: An engine control apparatus which may be employed in automotive vehicles. The engine control apparatus is equipped with at least one of a combustion parameter or a controlled variable arithmetic expression. The combustion parameter arithmetic expression defines combustion conditions of the engine needed to achieve required values of engine output-related values such as exhaust emissions. The controlled variable arithmetic expression defines how to operate actuators for an operation of the engine to meet desired combustion conditions of the engine. The use of the combustion parameter or controlled variable arithmetic expression achieves simultaneous agreement of the engine output-related values with required values without mutual interference between combustion parameters associated with the combustion conditions.

Abstract: An apparatus of estimating fuel injection state of a fuel injection system have at least three injectors. The first and second injectors have fuel pressure sensors respectively. The third injector has no fuel pressure sensor. The apparatus detects an injected cylinder waveform to the first injector when the first injector injects fuel. The apparatus detects a first non-injected cylinder waveform to the second injector when the first injector injects fuel. The apparatus calculates correlations between the injected cylinder waveform and the first non-injected cylinder waveform. The apparatus acquires a second non-injected cylinder waveform detected by the first or second fuel pressure sensor when the third injector injects fuel. The apparatus estimates fuel injection state injected from the third injector based on the second non-injected cylinder waveform and the correlations.

Abstract: A defective-portion detector has a detecting portion which detects a variation in fuel pressure as a fuel pressure waveform based on a detection value of a fuel pressure sensor and a computing portion which computes, based on the fuel pressure waveform, a plurality of injection-rate parameters required for identifying an injection-rate waveform corresponding to the fuel pressure waveform. Further, the detector has a determining portion which determines whether each learning value of the injection-rate parameters is an abnormal value and an identifying portion which identifies a defective portion in the fuel injection system based on a combination of abnormal learning values which the determining portion has determined.

Abstract: A fuel-injection condition detector includes a first approximate portion which approximates a plurality of fuel pressure values representing the descent pressure waveform or the ascent pressure waveform into a least-squares approximate line by least-squares method; and a weighting portion which applies a weight to the fuel pressure value. The weight is set greater as a difference between the fuel pressure and the least-squares approximate line is larger. Then, the weighted values are approximated into a weighted approximate line by the least-squares method.

Abstract: An engine control apparatus which may be employed in automotive vehicles. The engine control apparatus is equipped with at least one of a combustion parameter or a controlled variable arithmetic expression. The combustion parameter arithmetic expression defines combustion conditions of the engine needed to achieve required values of engine output-related values such as exhaust emissions. The controlled variable arithmetic expression defines how to operate actuators for an operation of the engine to meet desired combustion conditions of the engine. The use of the combustion parameter or controlled variable arithmetic expression achieves simultaneous agreement of the engine output-related values with required values without mutual interference between combustion parameters associated with the combustion conditions.

Abstract: An engine control apparatus which may be employed in automotive vehicles. The engine control apparatus is equipped with a controlled variable arithmetic expression which defines correlations between a plurality of combustion parameters and a plurality of controlled variables of actuators for control of an operation of the engine to calculate a combination of command values to be outputted to the actuators for regulating the controlled variables needed to achieve target values of the combustion parameters. When one of the command values is produced outside an allowable operation range of a corresponding one of the actuators, the engine control apparatus corrects or limits the one of the command values to an upper or a lower limit of the allowable operation range, thereby ensuring the stability in bringing engine output characteristics close to desired values.

Abstract: An engine control apparatus which may be employed in automotive vehicles. The engine control apparatus is equipped with a controlled variable arithmetic expression which defines correlations between combustion parameters associated with combustion conditions of an engine and controlled variables actuators for an operation of the engine. This eliminates the need for finding relations of optimum values of the controlled variables to the combustion parameters through adaptability tests, which results in a decrease in burden of an adaptability test work and a map-making work on manufacturers. The engine control apparatus also works to learn or optimize the controlled variable arithmetic expression based on actual values of the combustion parameters, thereby avoiding undesirable changes in correlations, as defined by the controlled variable arithmetic expression, due to a change in environmental condition.

Abstract: An engine control apparatus which may be employed in automotive vehicles. The engine control apparatus is equipped with at least one of a combustion parameter or a controlled variable arithmetic expression. The combustion parameter arithmetic expression defines combustion conditions of the engine needed to achieve required values of engine output-related values such as exhaust emissions. The controlled variable arithmetic expression defines how to operate actuators for an operation of the engine to meet desired combustion conditions of the engine. The use of the combustion parameter or controlled variable arithmetic expression achieves simultaneous agreement of the engine output-related values with required values without mutual interference between combustion parameters associated with the combustion conditions.

Abstract: A sensor system includes a sensor unit which has a pressure sensor, a temperature sensor and a selector switching between a pressure detection signal and a temperature detection signal. The sensor system further includes a processing unit which outputs a switching command signal to the selector and receives a detection signal from the sensor unit. The switching command signal is transmitted through a communication line and the detection signal is transmitted through a signal line. The detection signal is transmitted to the processing unit in a form of an analog signal.

Abstract: A fuel injection is carried out as n split injections. Each of injection quantities is defined by dividing an injection quantity into n fuel injections. A FCCB correction and an ISC correction are carried out while n split injection cycles are performed. A value obtained by adding up an FCCB correction for each injection cycle and an ISC correction for each injection cycle is updated and stored as a learned injection quantity. The learned injection quantity is calculated as an injection quantity correction for each cylinder to be added to a command injection quantity for each injection cycle.

Abstract: An injection ratio control system for an internal combustion engine performs a multi-injection, in which multiple pilot injections and a main injection are performed. The system prohibits a first injection among the pilot injections if a main injection quantity command value for the main injection is less than an N time(s) minimum guarantee determination value. An injection quantity for the first injection is added to the injection quantity for the main injection. Thus, the system controls an injection frequency per combustion in the multi-injection to prevent the use of a minute main injection quantity command value equal to or less than the N time(s) minimum guarantee determination value. As a result, the main injection is prevented from vanishing.

Abstract: A fuel injection system carries out a multi-injection. A preceding injection affects a pressure in a combustion chamber at a succeeding injection. In order to ensure an amount and timing of a succeeding injection, the ECU carries out a compensating process. In one embodiment, an injection period for the succeeding injection is corrected by varying a corrective value in accordance with parameters indicative of a pressure deviation. In another embodiment, each of the injection amounts for preceding and succeeding injections is corrected in accordance with deviations from a standard pressure respectively. The deviation is determined based on an intake pressure.

Abstract: An injection ratio control system for an internal combustion engine performs a multi-injection, in which multiple pilot injections and a main injection are performed. The system prohibits a first injection among the pilot injections if a main injection quantity command value for the main injection is less than an N time(s) minimum guarantee determination value. An injection quantity for the first injection is added to the injection quantity for the main injection. Thus, the system controls an injection frequency per combustion in the multi-injection to prevent the use of a minute main injection quantity command value equal to or less than the N time(s) minimum guarantee determination value. As a result, the main injection is prevented from vanishing.

Abstract: A fuel injection is carried out as n split injections. Each of injection quantities is defined by dividing an injection quantity into n fuel injections. A FCCB correction and an ISC correction are carried out while n split injection cycles are performed. A value obtained by adding up an FCCB correction for each injection cycle and an ISC correction for each injection cycle is updated and stored as a learned injection quantity. The learned injection quantity is calculated as an injection quantity correction for each cylinder to be added to a command injection quantity for each injection cycle.