A characteristic determining device is provided which determines fuel injection characteristics of a plurality of fuel injectors for an internal combustion engine. The characteristic determining device includes a pressure sensor and a plurality of pipes each of which connects between the pressure sensor and one of the fuel injectors. The pressure sensor is designed to have a plurality of pressure inputs from the respective fuel injectors through the pipes and outputs a signal indicative of a level of pressure in each of the fuel injectors. The characteristic determining device analyzes the signals from the first pressure sensor to determine the fuel injection characteristics of the respective fuel injectors. These arrangements result in a simplified structure of the characteristic determining device and a decreased manufacturing cost thereof.

A method for operating a combustion engine performing an injection quantity correction is described. A total injection quantity per pulse of an injector is divided into a plurality of smaller equal quantity pulses. The smaller quantity pulses are implemented in ballistic injector mode. On the basis of this step, a corresponding offset correction is carried out. After the offset correction has been applied, a further correction is carried out in linear injector mode. An additional alternative for performing an injection quantity correction without additional sensor hardware is thereby provided.

Systems and methods for determining fuel delay in a fuel injected engine with cylinders that may be deactivated are presented. In one example, the fuel injection delay is determined via a cylinder firing schedule array when the cylinder firing schedule array is available. The fuel injection delay is determined via weighted average of a fuel injection delay of a present engine cycle and a fuel injection delay of a past engine cycle when the cylinder firing schedule array is not available.

A method of controlling a skip-fire cylinder deactivation system of an engine system is provided. The method includes a controller deactivating a cylinder of the engine system to operate the engine system in a skip-fire mode. The method further includes determining a temperature of an injector tip nozzle associated with the cylinder and comparing the temperature of the injector tip nozzle to a threshold a temperature. In response to determining that the temperature of the injector tip nozzle is greater than the threshold temperature, the cylinder is activated by the controller.

A system and method of providing real-time calculation of heat flow in an engine. A piston is disposed in a cylinder of an engine block and movable relative to the cylinder in response to combustion inside the cylinder. A temperature of the combustion inside the cylinder, an average temperature of the wall of the cylinder, and a surface area of the wall of the cylinder based on timing of combustion are determined. An estimated temperature of the piston is derived from calculating a heat fraction to the piston in real-time, via a controller, based on the determined temperature of the combustion, the determined average temperature of the wall of the cylinder, and the determined surface area of the wall of the cylinder. A state of the engine is controlled based on the estimated temperature of the piston as derived from the real-time calculation of the heat fraction to the piston.

An engine includes a single cylinder, at least one sensor, a fuel injector, and a controller. The at least one sensor is configured to generate sensor data for an engine condition. The controller is configured to perform a comparison of the engine condition to a threshold and in response to the comparison, generate a first command to deactivate the fuel injector after a first predetermined time period and a second command to reactivate the fuel injector after a second predetermined time period.

An engine includes a single cylinder, at least one sensor, a fuel injector, and a controller. The at least one sensor is configured to generate sensor data for an engine condition. The controller is configured to perform a comparison of the engine condition to a threshold and in response to the comparison, generate a first command to deactivate the fuel injector after a first predetermined time period and a second command to reactivate the fuel injector after a second predetermined time period.

An engine assembly includes: a two-stroke internal combustion engine; a turbocharger operatively connected to the engine, the turbocharger having a compressor and an exhaust turbine; an intake pipe fluidly connected to the engine and to the compressor of the turbocharger; an exhaust tuned pipe fluidly connected to the engine and to the exhaust turbine of the turbocharger; a temperature sensor configured to generate a signal representative of a temperature of exhaust gas flowing within the exhaust tuned pipe; and a controller. The controller is configured to: determine a boost target pressure of the turbocharger based in part on the signal generated by the temperature sensor; and control the turbocharger to provide the boost target pressure to the engine. Methods for controlling an engine are also provided.

A method for a model-based open-loop and closed-loop control of an internal combustion engine includes the steps of: calculating, by an optimizer, a pre-optimized quality measure based on an operating situation, wherein, in calculating the pre-optimized quality measure, a plurality of discrete manipulated variables having a plurality of discrete settings are interpreted as a plurality of continuous manipulated variables having a continuous settings range; quantizing the plurality of continuous manipulated variables, and the plurality of continuous manipulated variables are set as a plurality of new discrete manipulated variables (SG(new)) having a plurality of discrete settings; and calculating, by the optimizer, a post-optimized quality measure based on the plurality of new discrete manipulated variables and the operating situation of the internal combustion engine, and the post-optimized quality measure is set as critical for an operating point of the internal combustion engine by the optimizer.

Systems and methods for operating an engine with deactivating and non-deactivating valves are presented. In one example, valves of a cylinder are deactivated in a closed state in response to an indication of degradation of a valve of the cylinder. Further, fuel flow to the cylinder may be stopped via ceasing to inject fuel to the cylinder.