Abstract: A fuel injection characteristic sensing device obtains an injection characteristic of a target injector (an injector of each cylinder of a multi-cylinder engine) at each time. The device has a program for sequentially sensing fuel pressure at a sensing point corresponding to a fuel pressure sensor, which is provided at a fuel inlet of each injector, based on an output of the fuel pressure sensor. The device has a program for detecting predetermined timings (injection timings such as an injection start timing and an injection end timing) in a series of operations concerning fuel injection of the injector of each cylinder based on the sequentially sensed fuel pressure. Thus, the injection characteristic at each time including a temporal characteristic change can be obtained.

Abstract: A fuel injection control device (ECU) for controlling injection supply of fuel to an engine is applied to an injector that has a valve body formed with a fuel injection hole, a needle accommodated in the valve body for opening and closing the injection hole, and a piezoelectric element for driving the needle such that the needle reciprocates and that can continuously adjust an injection rate in accordance with an injection command signal to the piezoelectric element. The fuel injection control device senses a fuel pressure waveform indicating a transition of fuel pressure fluctuation accompanying a predetermined injection of the injector based on an output of a fuel pressure sensor and calculates an injection command signal for approximating a predetermined injection parameter concerning the predetermined injection to a reference value of the parameter based on the sensed fuel pressure waveform.

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 includes a program for sequentially sensing fuel pressure fluctuating with injection of a predetermined injector of each cylinder of a multi-cylinder engine based on an output of a fuel pressure sensor, a program for detecting a diagram as a profile of a transition of a fuel quantity injected from the injector per unit time (i.e., an injection rate) at a present time based on the sequentially sensed fuel pressure transition, and a program for varying an injection command to the injector based on the diagram that is the profile of the injection rate transition and that is detected by the latter program and a predetermined basic diagram such that the diagram as the actual profile of the injection rate transition belongs to the basic diagram.

Abstract: A fuel injection characteristic detection apparatus is applied to a fuel feed system. The fuel feed system is configured to inject fuel into one of a cylinder, an intake passage, and an exhaust passage of an internal combustion engine by using a fuel injection valve. The fuel injection characteristic detection apparatus includes fuel pressure obtaining unit for successively obtaining pressure of fuel supplied to the fuel injection valve. The fuel injection characteristic detection apparatus further includes pulsation pattern storing unit for associating a pulsation pattern of fuel pressure, which accompanies an injection operation of the fuel injection valve, with at least a fuel injection mode and a fuel pressure level at a present time point and for storing the associated pulsation pattern in a storage medium.

Abstract: A sensor signal from a speed sensor is inputted into an ECU. The ECU calculates a rotation speed of a crankshaft in a predetermined period based on the sensor signal. The rotation speed is filtered by a frequency which is defined based on a combustion frequency of the engine to obtain a value corresponding to a current torque. The ECU calculates a workload of each cylinder based on the value corresponding to the current torque, and controls characteristic of each cylinder based on the workload.

Abstract: A rotation angle sensing device calculates an average value of calculation values of time necessary for rotation of each one of sections provided by equally dividing one rotation of a crankshaft. The device calculates an average value of the average values of the entire sections to calculate an entire section average value. The device calculates ratios of the average values of the respective sections to the entire section average value. The device eliminates an influence of rotation fluctuation of the crankshaft from the ratios by using reference ratios, which are calculated as ratios of the average values of the respective sections to the entire section average value in the case where there is no structural error. Thus, the device calculates learning values for compensating for the structural error.

Abstract: A rotation angle sensing device calculates an average value of calculation values of time necessary for rotation of each one of sections provided by equally dividing one rotation of a crankshaft. The device calculates an average value of the average values of the entire sections to calculate an entire section average value. The device calculates ratios of the average values of the respective sections to the entire section average value. The device eliminates an influence of rotation fluctuation of the crankshaft from the ratios by using reference ratios, which are calculated as ratios of the average values of the respective sections to the entire section average value in the case where there is no structural error. Thus, the device calculates learning values for compensating for the structural error.

Abstract: A sensor signal from a speed sensor is inputted into an ECU. The ECU calculates a rotation speed of a crankshaft in a predetermined period based on the sensor signal. The rotation speed is filtered by a frequency which is defined based on a combustion frequency of the engine to obtain a value corresponding to a current torque. The ECU calculates a workload of each cylinder based on the value corresponding to the current torque, and controls characteristic of each cylinder based on the workload.

Abstract: A fuel injection system includes an injector and a control device. The injector includes a control chamber that drive-controls a needle with a pressure therein. The control device determines a required injection amount in accordance with an operation state of an internal combustion engine, and controls a fuel injection amount injected from the injector through controlling an electric valve therein. The control device determines a geometric shape defined by a time axis and a lift-height change of the needle. The control device further divides the lift-height change of the needle during the period from when the needle starts moving up to when the needle starts moving down into a plurality of portions. The control device then evaluates the lift-height change of the needle in the plurality of portions based on a physical equation.

Abstract: During a short duration injection, a triangular geometry is drawn in terms of the injection rate with respect to time, while a trapezoidal geometry is drawn during a long duration injection. The ON timing of the drive pulse is determined to be at a valve opening pressure achieving time before the start point of formation in time of the geometry. An injection pulse duration is determined from “the valve opening pressure achieving time+a needle rise time—a valve closing pressure achieving time,” and then the OFF timing of the drive pulse is determined.