Abstract: An electronic control unit detects a manner of fluctuation of a fuel pressure with injection of fuel by a fuel injection valve with the use of a fuel pressure sensor, and calculates a tendency of deviation of an actual fuel injection characteristic of the fuel injection valve with respect to a basic fuel injection characteristic on the basis of a result of comparison between a detected temporal waveform and a basic temporal waveform. The tendency of deviation is reflected at a predetermined reflection rate (R) at the time of updating a learned value (Gij) for compensating for an individual difference of the fuel injection valve. The predetermined reflection rate (R) is increased when an accumulated value (D) of a vehicle travel distance is shorter than a predetermined value (Dth) as compared with when the accumulated value (D) is longer than or equal to the predetermined value (Dth).

Abstract: A device executes a power limiting process when the number of pressure sensors determined to be normal in a second determination process made by a second processing unit is smaller than or equal to one. When only one pressure sensor is determined to be normal through the second determination process, and when that pressure sensor and a pressure sensor connected to only a first processing unit are determined to be normal in a first determination process made by the first processing unit, a process associated with fuel injection based on a detected value of the pressure sensor determined to be normal in the second determination process is executed, and a degree of limiting engine power through the power limiting process is reduced as compared with when both the pressure sensors are determined to be abnormal in the first determination process.

Abstract: An electronic control unit, in an idle operating state, detects a crankshaft rotation fluctuation in each cylinder using a crank angle sensor, and updates an individual correction value for a control value for each fuel injection valve as a first learned value such that a degree of deviation in the crankshaft rotation fluctuation among the cylinders reduces. The electronic control unit uses a fuel pressure sensor to detect a manner of a fuel pressure fluctuation with fuel injection by each fuel injection valve, and updates an individual correction value for a control value for each fuel injection valve as a second learned value based on a result of comparison between a detected temporal waveform and a basic temporal waveform. In an idle operating state, a learning rate of the second learned value is reduced until the first learned value converges for the first time as compared with after its convergence.

Abstract: In order to estimate the cetane number of a fuel, fuel injection is executed by controlling the driving of a fuel injection valve by a prescribed amount. The amount of change in the rotation of a diesel engine generated in response to the fuel injection is detected, and the cetane number of the fuel is estimated on the basis of this amount of change in the rotation. The actual amount of fuel injected from the fuel injection valve is detected, and when the difference between the amount actually detected and the prescribed amount is equal to or greater than a threshold value, the execution of the fuel cetane number estimation process is restricted.

Abstract: An electronic control unit detects an index value of an amount of generated heat of fuel to be combusted in a diesel engine. The electronic control unit also executes the injection of a predetermined amount of the fuel to estimate a cetane number of the fuel and calculates an index value of output torque of the diesel engine generated with that execution. Then, the electronic control unit calculates an estimated value of the cetane number of the fuel based on the index value of the output torque and the index value of the amount of generated heat.

Abstract: This apparatus is applied to an engine equipped with a fuel supply system that supplies pressure-increased fuel to a fuel injection valve, and performs the fuel injection from the injection valve in one combustion cycle by a multiple injection process that includes a pre-injection and a main injection that are executed with an interval therebetween. The apparatus calculates a deviation between a required value (one-dot chain line) and an actual value (solid line) regarding the end timing of the pre-injection, based on the manner of fluctuation of the fuel pressure in the fuel injection that is detected by a pressure sensor. A target main injection timing and a target pre-interval are individually set on the basis of the state of operation of the engine. Based on the deviation, the target main injection timing and the target pre-interval, the apparatus sets control target values regarding the execution period of the pre-injection.

Abstract: A device executes a power limiting process when the number of pressure sensors determined to be normal in a second determination process made by a second processing unit is smaller than or equal to one. When only one pressure sensor is determined to be normal through the second determination process, and when that pressure sensor and a pressure sensor connected to only a first processing unit are determined to be normal in a first determination process made by the first processing unit, a process associated with fuel injection based on a detected value of the pressure sensor determined to be normal in the second determination process is executed, and a degree of limiting engine power through the power limiting process is reduced as compared with when both the pressure sensors are determined to be abnormal in the first determination process.

Abstract: An electronic control unit, in an idle operating state, detects a crankshaft rotation fluctuation in each cylinder using a crank angle sensor, and updates an individual correction value for a control value for each fuel injection valve as a first learned value such that a degree of deviation in the crankshaft rotation fluctuation among the cylinders reduces. The electronic control unit uses a fuel pressure sensor to detect a manner of a fuel pressure fluctuation with fuel injection by each fuel injection valve, and updates an individual correction value for a control value for each fuel injection valve as a second learned value based on a result of comparison between a detected temporal waveform and a basic temporal waveform. In an idle operating state, a learning rate of the second learned value is reduced until the first learned value converges for the first time as compared with after its convergence.

Abstract: An electronic control unit detects a manner of fluctuation of a fuel pressure with injection of fuel by a fuel injection valve with the use of a fuel pressure sensor, and calculates a tendency of deviation of an actual fuel injection characteristic of the fuel injection valve with respect to a basic fuel injection characteristic on the basis of a result of comparison between a detected temporal waveform and a basic temporal waveform. The tendency of deviation is reflected at a predetermined reflection rate (R) at the time of updating a learned value (Gij) for compensating for an individual difference of the fuel injection valve. The predetermined reflection rate (R) is increased when an accumulated value (D) of a vehicle travel distance is shorter than a predetermined value (Dth) as compared with when the accumulated value (D) is longer than or equal to the predetermined value (Dth).

Abstract: A cetane number estimation apparatus injects fuel from a fuel injection valve in a diesel engine based on a target fuel injection amount, calculates an indicator of output torque of the diesel engine produced through fuel injection, and estimates the cetane number of the fuel using the calculated indicator. The cetane number estimation apparatus includes a pressure sensor for detecting fuel pressure varied by variation in actual fuel pressure in the fuel injection valve at the time of the fuel injection. The cetane number estimation apparatus also has a pressure correcting section that is adapted to calculate actual operating characteristics of the fuel injection valve based on a variation waveform of the detected fuel pressure and corrects the target fuel injection amount based on the difference between the calculated actual operating characteristics and prescribed reference operating characteristics.

Abstract: In order to estimate the cetane number of a fuel, fuel injection is executed by controlling the driving of a fuel injection valve by a prescribed amount. The amount of change in the rotation of a diesel engine generated in response to the fuel injection is detected, and the cetane number of the fuel is estimated on the basis of this amount of change in the rotation. The actual amount of fuel injected from the fuel injection valve is detected, and when the difference between the amount actually detected and the prescribed amount is equal to or greater than a threshold value, the execution of the fuel cetane number estimation process is restricted.

Abstract: An electronic control unit detects an index value of an amount of generated heat of fuel to be combusted in a diesel engine. The electronic control unit also executes the injection of a predetermined amount of the fuel to estimate a cetane number of the fuel and calculates an index value of output torque of the diesel engine generated with that execution. Then, the electronic control unit calculates an estimated value of the cetane number of the fuel based on the index value of the output torque and the index value of the amount of generated heat.

Abstract: An electronic controller for a diesel engine (1) performs primary injection control in which primary injection of fuel is controlled based on an operational status of the diesel engine and additional injection control in which additional injection of the fuel is controlled for estimation of a cetane number of the fuel. The electronic controller includes a control means that, as the additional injection control, causes a plurality of fuel injections to be performed at different injection timings as the additional injection, calculates the amount of increase in torque of a crankshaft (14) due to each of the fuel injections, estimates injection timing at which misfiring starts to occur based on a trend of variation in the calculated torque increase amount as the injection timing of the fuel injections is shifted in one direction, and estimates the cetane number of the fuel based on the estimated injection timing.

Abstract: A fuel injection amount control apparatus for an internal combustion engine includes an ECU that commands a learning-purpose injection when a first learning condition regarding operation state and a second learning condition regarding load connection state are satisfied, and calculates an injection performance value that corresponds to the actual injection amount based on the amount of change in rotation speed, and further determines whether a delay of the learning process is permitted based on whether the learning process, despite occurrence of the delay, can be completed before the injector performance reaches a permissible limit value, and forces, when the delay is not permitted, the load connection state to be a specific connection state so as to satisfy the second learning condition. When it is determined that the delay of the learning process is permitted, the delay is permitted until the two learning conditions are satisfied.

Abstract: A cetane number estimation apparatus injects fuel from a fuel injection valve in a diesel engine based on a target fuel injection amount, calculates an indicator of output torque of the diesel engine produced through fuel injection, and estimates the cetane number of the fuel using the calculated indicator. The cetane number estimation apparatus includes a pressure sensor for detecting fuel pressure varied by variation in actual fuel pressure in the fuel injection valve at the time of the fuel injection. The cetane number estimation apparatus also has a pressure correcting section that is adapted to calculate actual operating characteristics of the fuel injection valve based on a variation waveform of the detected fuel pressure and corrects the target fuel injection amount based on the difference between the calculated actual operating characteristics and prescribed reference operating characteristics.

Abstract: This apparatus is applied to an engine equipped with a fuel supply system that supplies pressure-increased fuel to a fuel injection valve, and performs the fuel injection from the injection valve in one combustion cycle by a multiple injection process that includes a pre-injection and a main injection that are executed with an interval therebetween. The apparatus calculates a deviation between a required value (one-dot chain line) and an actual value (solid line) regarding the end timing of the pre-injection, based on the manner of fluctuation of the fuel pressure in the fuel injection that is detected by a pressure sensor. A target main injection timing and a target pre-interval are individually set on the basis of the state of operation of the engine. Based on the deviation, the target main injection timing and the target pre-interval, the apparatus sets control target values regarding the execution period of the pre-injection.

Abstract: A cetane number estimation method is provided in which: the preliminary injection is preformed multiple times at different compression end temperatures with a fuel tank (26) containing fuel having a predetermined cetane number, and an engine torque increase caused by each preliminary injection is calculated and the relation between the compression end temperatures at the respective preliminary injections and the engine torque increases caused by the respective preliminary injections is determined; the compression end temperature and the engine torque increase at a predetermined reference point on the relation are recorded as a basic compression eng temperature and a basic engine toque increase; the preliminary injection is performed at the basic compression end temperature and an engine torque increase caused by this preliminary injection is calculated; and the cetane number of fuel is estimated based on the relation between the calculated engine torque increase and the basic engine torque increase.

Abstract: A packet relay apparatus for suppressing a burst transfer of packets being relayed to improve the quality and reliability of packet communication. In the packet relay apparatus, an arrival time measurement block measures the arrival time of an input packet to generate arrival time information; a packet classification block classifies the packet as an output-interval-control packet, which requires output interval control, or a non-output-interval-control packet, which does not require output interval control, to generate classification information; a packet distribution block receives the packet which has been processed and switched and places the packet in an appropriate queue according to the classification information; and a schedule management block performs relay output control in accordance with the arrival time information such that the output intervals of output-interval-control packets become equal to the input intervals obtained when the packets were input to the apparatus.

Abstract: A fuel injection amount control apparatus for an internal combustion engine includes an ECU that commands a learning-purpose injection when a first learning condition regarding operation state and a second learning condition regarding load connection state are satisfied, and calculates an injection performance value that corresponds to the actual injection amount based on the amount of change in rotation speed, and further determines whether a delay of the learning process is permitted based on whether the learning process, despite occurrence of the delay, can be completed before the injector performance reaches a permissible limit value, and forces, when the delay is not permitted, the load connection state to be a specific connection state so as to satisfy the second learning condition. When it is determined that the delay of the learning process is permitted, the delay is permitted until the two learning conditions are satisfied.

Abstract: A cetane number estimation method is provided in which: the preliminary injection is preformed multiple times at different compression end temperatures with a fuel tank (26) containing fuel having a predetermined cetane number, and an engine torque increase caused by each preliminary injection is calculated and the relation between the compression end temperatures at the respective preliminary injections and the engine torque increases caused by the respective preliminary injections is determined; the compression end temperature and the engine torque increase at a predetermined reference point on the relation are recorded as a basic compression eng temperature and a basic engine toque increase; the preliminary injection is performed at the basic compression end temperature and an engine torque increase caused by this preliminary injection is calculated; and the cetane number of fuel is estimated based on the relation between the calculated engine torque increase and the basic engine torque increase.