A method is provided for determining the opening and/or closing time of the nozzle pin in an injection valve in an internal combustion engine having a plurality of cylinders. The nozzle pin is directly driven by a piezo actuator. The piezo voltage and/or the piezo charge at the respective piezo actuator functioning as a sensor is measured for the corresponding injection pulse in a plurality of cylinders of the internal combustion engine, and the median value of the measured voltage and/or charge values of the piezo actuators for the plurality of cylinders for the corresponding injection pulse is calculated. The obtained median value is then used as a replacement value for determining the opening and/or closing time in case of non-detectability or disruption of the needle opening and/or needle closing information.

A control apparatus of an engine system, the engine system including an engine, a VGT configured to control a boost pressure applied to the engine by adjust an angle of a vane provided in a turbine, and an EGR valve configured to control an amount of a recirculated exhaust gas, includes a target value determiner determining a target boost pressure and a target intake air amount based on an engine speed and a fuel injection amount, an EGR valve controller calculating a target EGR mass flow rate based on the target boost pressure and the target intake air amount and determining an EGR valve opening rate, and a turbocharger controller performing a sliding mode control using the calculated target EGR mass flow rate as a parameter to calculate a target compressor power and a target turbocharger mass flow rate and determining a turbine vane opening rate.

Proposed is a method for open-loop and closed-loop control of an internal combustion engine (1), the rail pressure (pCR) being controlled via a low pressure-side suction throttle valve (4) as the first pressure-adjusting element in a rail pressure control loop. The invention is characterized in that a rail pressure disturbance variable is generated to influence the rail pressure (pCR) via a high pressure-side pressure control valve (12) as the second pressure-adjusting element, by means of which fuel is redirected from the rail (6) into a fuel tank (2).

A method for operating an internal combustion engine having an injection system which has a high-pressure accumulator, wherein a high pressure in the high-pressure accumulator is regulated via a suction throttle on the low-pressure side as a first pressure control member in a first high-pressure control loop, wherein in a normal operation a high-pressure disturbance variable is produced via a pressure control valve on the high-pressure side as a second pressure control member, via which fuel is redirected from the high-pressure accumulator to a fuel reservoir. For this purpose, the high pressure in a safety operation is regulated by the pressure control valve via a second high pressure control loop, or, in the safety operation, a maximum fuel volume flow is continuously redirected from the high pressure accumulator to the fuel reservoir via the pressure control valve.

A method for regulating the charge pressure p.sub.boost of a supercharged internal combustion engine is disclosed. The method may include adjusting each of two wastegates, a variable turbine geometry, and a downstream compressor bypass valve to regulate engine boost pressure as a function of a first setpoint value for pressure between compressors and a pressure difference in a first regulation loop, a second setpoint value for pressure downstream of multiple compressors, and the pressure difference in a second regulation loop.

A control apparatus for an internal combustion engine is configured to: calculate measured data of MFB based on in-cylinder pressure detected by an in-cylinder pressure sensor; execute engine control based on a measured value of a specified fraction combustion point that is calculated based on the measured data of MFB; and calculate a first correlation index value for the measured data (current data) and the reference data of MFB and a second correlation index value for the current data and the immediately preceding past data. The engine control is suspended that uses the measured data of the specified fraction combustion point based on the current data when both of the first correlation index value and the second correlation index value are less than a determination value.

Feedback control is executed based on a measured CA10 and a measured CA50 that are calculated based on measured data for MFB. The measured data is corrected in accordance with a pattern of a waveform of measured data for a heat release amount, and measured data for MFB is calculated. A correlation index value showing a degree of correlation between the calculated measured data for MFB and reference data corresponding thereto is calculated. If the correlation index value is less than a determination value, control is performed to prohibit reflection in the aforementioned feedback control of each of the measured CA10 and the measured CA50 which are measured in the combustion cycle in which the relevant correlation index value is calculated.

A control process for controlling an engine speed governor of an engine is provided. The process comprises the steps of calculating the current engine power being developed by the engine, and determining an appropriate engine speed for the current engine power based upon a first engine map. The process then instructs the speed governor to adjust the engine speed in accordance with the first map if required. The process monitors for desired engine power requests, and calculates a power ratio of desired engine power versus current engine power upon receiving a desired engine power request. The process then establishes an engine speed adjustment value based upon a second engine map of power ratio versus speed adjustment value, and instructs the speed governor to adjust the engine speed in accordance with the speed adjustment value. A speed governor system incorporating the control process, and a work machine or vehicle incorporating such a system are also provided.

A control device for an internal combustion engine comprises an air-fuel ratio control part configured to control the air-fuel ratio of the exhaust gas and a heating control part configured to control the heating of the air-fuel ratio sensors. The heating control part controls the sensor heaters so that the temperature of the upstream air-fuel ratio sensor becomes less than the activation temperature and so that the temperature of the downstream air-fuel ratio sensor becomes the activation temperature or more while the internal combustion engine is stopped by the automatic stop function. The air-fuel ratio control part controls the exhaust air-fuel ratio based on the outputs of the two air-fuel ratio sensors during engine operation and control the air-fuel ratio temporarily based on only the output of the downstream air-fuel ratio sensor after the internal combustion engine has been restarted after automatic stop.