Methods and systems are provided for controlling fuel injection to cylinders of an engine in a vehicle. In one example, a method comprises monitoring an electrical energy profile associated with a fuel injector that has been commanded to inject a predetermined amount of a fuel into an engine cylinder, inferring a fuel injection pressure based on the electrical energy profile, and controlling a subsequent fuel injection based on the inferred fuel injection pressure. In this way, fuel injection may be controlled without relying on a pressure sensor in a fuel rail that supplies fuel to the fuel injector, under conditions where the fuel rail does not include the pressure sensor or where the pressure sensor is degraded.

An energization instruction switch switches energization instruction signals to instruct energization of fuel injection valves. A first cylinder designation switch designates one of the energization instruction signals to designate a valve closing detection cylinder. A valve closing detection unit monitors downstream voltage of the fuel injection valve to detect occurrence of an inflection point in change of the downstream voltage to detect a valve closing. A second cylinder designation switch designates one of the downstream voltages and designates the valve closing detection cylinder. A valve closing time measuring unit measures a valve closing time, which is from a switching timing of the energization instruction signal from ON to OFF to a valve closing detection timing, for injection of the valve closing detection cylinder. A valve closing time learning unit learns the valve closing time measured by the valve closing time measuring unit.

An ECU as a valve body operation estimation device includes a sampling unit that obtains at least one of voltage and current of the electromagnetic coil as sample values at intervals of a predetermined time in a sampling period set based on a predetermined reference timing, a variation calculation unit that calculates a degree of variation of the sample values obtained in the sampling period, a variation waveform which represents a change of the degree of variation caused by shifting the reference timing including a point at which the degree of variation reduces and then rises as the reference timing is delayed, the point referred to as a rising start point, and a timing estimation unit that estimates an operation timing of a valve body based on the reference timing at the rising start point.

Provided is a knocking detection apparatus capable of reducing erroneous determination of knocking during transition, and improving knocking detection accuracy regardless of whether an engine is in steady operation or transient operation. A knocking detection apparatus according to the present invention estimates a background level based on an operating state of an internal combustion engine, and calculates a knocking determination index by using the estimated value.

A method for operating an internal combustion engine with detection of the fuel used for injection is described. In the method, the elasticity modulus of the fuel to be injected is determined at a first and a second injection pressure. A difference value is calculated from the difference between the two elasticity modulus values related to the pressure difference and is compared with a differentiating value. The fuel being used is detected depending on whether the difference value is above or below the differentiation value. In particular, the method is used for differentiating diesel fuel EN590 and biodiesel.

Methods and systems are provided for reducing errors in estimated fuel rail pressure incurred at the time of a scheduled injection event due to engine-driven cyclic fuel rail pressure changes. In one example, a pulse-width commanded during a scheduled injection event is determined as a function fuel rail pressure samples collected over a moving window that is customized for the corresponding fuel injector. In another example, the commanded pulse-width is determined as a function of an average fuel rail pressure sampled during a quiet zone of injector operation and predicted fuel rail pressure altering events occurring between the quiet zone and the scheduled injection event.

Methods and systems are provided for reducing errors in estimated fuel rail pressure incurred at the time of a scheduled injection event due to engine-driven cyclic fuel rail pressure changes. In one example, a pulse-width commanded during a scheduled injection event is determined as a function fuel rail pressure samples collected over a moving window that is customized for the corresponding fuel injector. In another example, the commanded pulse-width is determined as a function of an average fuel rail pressure sampled during a quiet zone of injector operation and predicted fuel rail pressure altering events occurring between the quiet zone and the scheduled injection event.

System, apparatus, and methods are disclosed for improving vehicle acceleration performance. One or more devices of the internal combustion engine system are controlled in response to a torque transition event indicator and/or one or more vehicle acceleration event indicators indicating a vehicle acceleration event is imminent to improve vehicle response during acceleration.

In some embodiments of the present disclosure, an electric motor is used to generate correction torques to counteract unwanted torque pulses generated by an internal combustion engine during a cylinder deactivation mode. In some embodiments, the electric motor may be mounted to an accessory drive such as a power take-off mechanism or a front end accessory drive (FEAD). In some embodiments, the correction torques may be determined using an engine model. The correction torques help to reduce or eliminate noise, vibration, and/or harshness (NVH) during the cylinder deactivation mode.

A method is provided for adjusting timing of fuel injection into a combustion chamber of a compression-ignition engine. The method includes detecting a request for zero torque generation by the engine and cutting-off delivery of fuel into the combustion chamber during the detected zero torque request. The method additionally includes issuing a command to inject a test quantity of fuel into the combustion chamber during the detected request for zero torque generation. The method also includes assessing a timing delay between the command to inject the test quantity of fuel and a start of the test quantity injection, and determining a compensation for the assessed timing delay. The method additionally includes detecting a request for positive torque generation by the engine. The method further includes commanding a shift in the timing of fuel injection into the combustion chamber by the determined compensation during the engine's positive torque generation.