Disclosed is a combustion system design method based on a target heat release rate, which belongs to the technical field of diesel engine combustion chamber design. The method includes: obtaining an ideal heat release rate based on Sabathe-Miller cycle; simulating the ideal heat release rate based on a double-Wiebe function and obtaining the target heat release rate; constructing a mapping relation among the heat release rate, piston geometric parameters and fuel injection parameters, which includes target start of combustion being an function of fuel injection timing and ignition delay, premixed combustion parameters being functions of throat radius, injection pressure and nozzle diameter, and diffusion combustion being a function of piston pit depth; solving target piston geometric parameters and target fuel injection parameters based on the mapping relation; and then designing a combustion system. The method does not depend on experience and multi-scheme design, greatly shortens the combustion system design.

A control device for an internal combustion engine controls a control object device based on an output value of a relative angle sensor that detects a relative angle of an output shaft of an actuator, and an output value of an absolute angle sensor that detects an absolute angle of a drive shaft coupled to the output shaft of the actuator via a speed reducer. In this event, the control device for the internal combustion engine corrects an output value of the absolute angle sensor based on an absolute angle of the drive shaft that is obtained from an output value of the relative angle sensor using, as a reference point, an output value of the absolute angle sensor at the start-up of the internal combustion engine, and an output value of the absolute angle sensor.

A method for correcting injection behavior of a fuel injector includes calculating a nominal value of a fuel injector family characteristic for an average fuel injector from a family of fuel injectors as a multi-variable function of engine operating conditions, calculating a corrected value of the fuel injector family characteristic as a function of the nominal value, and employing the corrected value when actuating the fuel injector to inject fuel.

A device and a method for actuating an injector in a fuel-injection system of an internal combustion engine are described. Using a first calibration method and based on a control parameter, an injector parameter which characterizes the injection process is determined. Starting from this injector parameter, a first feature is determined for calibrating the injector. A second calibration method determines a second feature for calibrating the injector, based on an engine parameter. The first calibration method is monitored on the basis of the second feature.

The present disclosure relates to injection valves. The teachings thereof may be embodied in various valves, fuel injectors, and methods for controlling valves. An example method for setting operational parameters of a fuel injector may include: determining a measurement-specific maximum current value; applying a voltage pulse to the coil drive of the fuel injector; detecting a time curve of the current intensity of a current flowing through the coil drive; ending the voltage pulse when the detected current intensity reaches the maximum current value; and storing the time curve of the detected current intensity. The method may include generating a plurality of differential curves each based on two stored time curves of the detected current intensity for successive measurements; determining a peak current for driving the actuator of the fuel injector based at least in part on the plurality of differential curves; and operating the coil at the determined peak current.

A fuel injection control apparatus of an engine, which can inhibit a learning time from lengthening, is provided. With the fuel injection control apparatus, learning control over one of a first fuel injection valve and a second fuel injection valve is exercised in an operating region of the engine where fuel is injected from each of the first fuel injection valve and the second fuel injection valve, and the change rate of a learning value by the learning control is altered in accordance with an injection ratio between the first fuel injection valve and the second fuel injection valve.

A method to monitor an operating characteristic in a combustion engine: creating a monitoring matrix divided into a number of sections for storage of information, wherein each section is associated with specific intervals of engine speed and torque requested from the engine T.sub.1. When the engine is used during an operational time window with a pre-determined duration, measuring or estimating an operating characteristic and associating the characteristic with the monitoring matrix's respective section, associated with the current engine speed and the torque requested. For each section in the monitoring matrix, calculating at least one statistical parameter describing the operating characteristic associated with this section during the current operational time window; storing the statistical parameter(s) in the respective section. At the end of the operational time window, storing information in the monitoring matrix in an individual storage matrix associated with the operational time window, wherein the monitoring matrix is emptied of information.

A method of operating a fuel injector of an internal combustion engine includes setting a value of a target fuel quantity to be injected by the fuel injector, initializing a value of a fuel quantity requested from the fuel injector to the value of the target fuel quantity, and correcting the value of the requested fuel quantity. A first learning cycle is performed to correct the value of the requested fuel quantity in which a difference between the target fuel quantity and the injected fuel quantity is calculated and added to the requested fuel quantity to provide a corrected value. The corrected value of the requested fuel quantity is used to determine a reference value of an energizing time that causes the fuel injector to inject a fuel quantity corresponding to the target fuel quantity. The fuel injector is operated based on the determined reference value of the energizing time.

A valve reference position-learning device for an internal combustion engine, which is capable of accurately learning the reference position of a valve both before and after the warm-up of the engine, while properly reflecting thereon a deviation of the reference position caused by the thermal elongation of the valve and drive system after the warm-up of the engine. The valve reference position-learning device calculates and updates a learned value of the reference position of the wastegate valve both at and after the start of the engine, by first and second learnings, respectively. The learned value calculated by the first learning is stored as an existing learned value. Further, at the start of the engine, if the calculation of the learned value is not completed, the learned value is set to the existing stored learned value.

When executing a Local-learning, an air-fuel ratio detecting time is corrected so that a dispersion of detection values of an air-fuel ratio sensor becomes a maximum value in one cycle of an engine. While executing a cylinder-by-cylinder air-fuel ratio control, a Global-learning is executed. In the Global-learning, the air-fuel ratio detecting time is corrected based on a relationship between a variation in estimated air fuel ratio of each cylinder and a variation in fuel quantity correction value of each cylinder. In the Global-learning, a computer computes a correlation coefficient between the variation in estimated air-fuel ratio and the variation in fuel quantity correction value of the cylinder for each case where the cylinder assumed to correspond to the estimated air fuel ratio is hypothetically varied in multiple ways. Then, the air-fuel ratio detecting time is corrected so that this correlation coefficient becomes a maximum value.