A method for operating an internal combustion engine of a drive system for a motor vehicle, the internal combustion engine being designed for operation using various types of fuel, has the following steps: querying operating parameters of fuel-relevant functions of the drive system by means of a central fuel coordination device of a central engine coordination device, determining possible types of fuel for operating the internal combustion engine, based on the queried operating parameters and predefined fuel release conditions, by means of the central fuel coordination device, selecting a type of fuel for operating the internal combustion engine, based on the determined possible types of fuel and at least one predefined selection criterion, by means of the central fuel coordination device, transmitting information identifying the selected type of fuel from the central fuel coordination device to a central engine control unit of the central engine coordination device, and operating the internal combustion engine with the selected type of fuel by means of the central engine control unit.

A storage device stores a first mapping that receives, as an input, first input variables including a previously estimated value for a fuel temperature variable, a pump variable on a state of a fuel pump, a first engine variable on a state of an engine, and an outside air temperature variable on an outside air temperature, and outputs the fuel temperature variable. Further, an execution device is configured to acquire the first input variables and estimate the fuel temperature variable by applying the acquired first input variables to the first mapping. Therefore, it is possible to estimate the fuel temperature variable by applying the first input variables to the first mapping even without providing a temperature sensor.

Methods and systems for flex fuel engines that have both port fuel injection and direct injection. Operating an engine system includes determining a percent of ethanol in a fuel and determining whether the percent of ethanol is greater than a predetermined threshold. When the percent of ethanol is greater than the predetermined threshold, fuel is supplied only through the direct injection injectors. When the percent of ethanol is not greater than the predetermined threshold, fuel is supplied through a combination of the direct injection injectors and port fuel injection injectors.

In an alcohol concentration estimation apparatus for an engine, a first crank angular speed (ω1) within a first predetermined interval overlapping with the compression top dead center is calculated, and a first variation amount (Δω1) is calculated by subtracting ω1 from an average engine speed. A second crank angular speed (ω2) within a second predetermined interval overlapping with the combustion bottom dead center is calculated, and a second variation amount (Δω2) is calculated by subtracting ω1 from ω2. In a relationship between air fuel ratio A/F and an indicated mean effective pressure (IMEP)/charging efficiency (ηc) of the engine when the engine is operated with a predetermined fuel injection map indicating a relationship between A/F and IMEP/ηc for each desired alcohol concentration, IMEP/ηc is substituted by Δω2/Δω1 ratio to estimate an alcohol concentration in fuel. The alcohol concentration estimation apparatus eliminates requirement of sensors for detecting an intake air mass.

A storage device is configured to store a first mapping that receives, as an input, a first input variable including a cam phase variable on present and past phases of a cam, and output a pulsating variable on a pulsating component. The execution device is configured to acquire the first input variable and estimate the pulsating variable by applying the acquired first input variable to the first mapping. Therefore, it is possible to estimate the pulsating variable without providing a low-pressure fuel pressure sensor by estimating a fuel pressure variable by applying the first input variable to the first mapping.

A fuel pressure estimation system estimates a fuel pressure variable on a fuel pressure in a supply pipe for an engine apparatus including an engine having a fuel injection valve, and a fuel supply device having a fuel pump that supplies the fuel in a fuel tank to the supply pipe, and includes a storage device and an execution device. The storage device stores a first mapping that receives, as an input, first input variables including a pump variable, a consumption flow rate variable on a consumption flow rate of the fuel, and a property variable on a property of the fuel, and outputs the fuel pressure variable. The execution device acquires the first input variables and estimates the fuel pressure variable by applying the first input variables to the first mapping.

A storage device stores a first mapping that receives, as an input, first input variables including a previously estimated value for a fuel temperature variable, a pump variable on a state of a fuel pump, a first engine variable on a state of an engine, and an outside air temperature variable on an outside air temperature, and outputs the fuel temperature variable. Further, an execution device is configured to acquire the first input variables and estimate the fuel temperature variable by applying the acquired first input variables to the first mapping. Therefore, it is possible to estimate the fuel temperature variable by applying the first input variables to the first mapping even without providing a temperature sensor.

A fuel pressure estimation system estimates a fuel pressure variable on a fuel pressure in a supply pipe for an engine apparatus including an engine having a fuel injection valve, and a fuel supply device having a fuel pump that supplies the fuel in a fuel tank to the supply pipe, and includes a storage device and an execution device. The storage device stores a first mapping that receives, as an input, first input variables including a pump variable, a consumption flow rate variable on a consumption flow rate of the fuel, and a property variable on a property of the fuel, and outputs the fuel pressure variable. The execution device acquires the first input variables and estimates the fuel pressure variable by applying the first input variables to the first mapping.

A fuel control system (300) for fuel consumption calculation for a fuel and water mixture is provided. The fuel control system (300) includes a mixer (330), a fuel source (310) fluidly coupled to the mixer (330), the fuel source (310) being configured to measure a flow of fuel to the mixer (330), a water source (315) fluidly coupled to the mixer (330), the water source (315) being configured to measure a flow of water to the mixer (330), and a mixture flow meter (5) fluidly coupled to the mixer (330). The mixture flow meter (5) is configured to receive and measure properties of a fuel/water mixture from the mixer (330).

A method for operating a vehicle having a gasoline engine includes determining a density of a gasoline to be combusted in the gasoline engine, determining a stoichiometric air demand, determining a critical temperature from the density of the gasoline to be combusted and the stoichiometric air demand, and adapting countermeasures to prevent vapor bubbles based on the determined critical temperature.