Sensing combustion events using a resistive based oxygen sensor exposed to exhaust gases of a periodic combustion process in a combustion engine. The oxygen sensor is disposed in the exhaust plenum of the engine and includes a metal oxide semiconductor layer bridging a gap between first and second electrodes. Spikes in the resistance of the metal oxide semiconductor layer, caused by its reaction to transient changes in the oxygen level and exhaust temperature, are indicated in a combustion signal. The combustion signal may be used to monitor for combustion misfire event(s). Further, a combustion misfire event may be detected by comparing the detected spike timing with expected spike timing, with a spike not being present at a time when a spike is expected indicating a combustion misfire event. Related devices and systems are also disclosed.

An estimation device applicable to a combustion system having an internal combustion engine includes a mixing acquisition unit, a combustion amount estimation unit, a region estimation unit, and a timing estimation unit. The mixing acquisition unit acquires a mixing ratio of various components contained in fuel used for combustion in the internal combustion engine. The combustion amount estimation unit estimates a combustion amount of fuel caused by a post combustion generated by injecting fuel into a combustion chamber of the internal combustion engine by post injection, based on the mixing ratio acquired by the mixing acquisition unit. The region estimation unit estimates a combustion region of the post combustion in the combustion chamber based on the mixing ratio. The timing estimation unit estimates an ignition timing at which ignition occurs in the combustion chamber by the post injection based on the mixing ratio.

A control device for an internal combustion engine includes at least one processor and a memory configured to store a program. The at least one processor is configured to execute, by executing the program, a process of deciding a manipulated variable of the internal combustion engine from a control input value, in accordance with a predetermined conversion rule, a process of calculating a sample value of the controlled variable, a process of calculating a reference expectation value of the controlled variable from the control input value, a process of performing a hypothesis test for a null hypothesis that an average value of a predetermined number of recent sample values of sample values of the controlled variable is equal to the reference expectation value, and a process of modifying the conversion rule by an adaptive control when the null hypothesis is rejected.

A controller includes a valve control unit and a target calculation unit. The valve control unit is configured to control a fuel injection valve such that divergence decreases between an ignition delay of fuel injected into a cylinder through main injection and an ignition delay target value. The target calculation unit is configured to calculate the ignition delay target value such that the ignition delay target value decreases as estimated ignitability of the fuel in the cylinder increases during an engine operation in a region where diffusion combustion and premix combustion are both performed, the ignitability of the fuel in the cylinder being estimated based on a parameter that varies the ignitability.

Variable compression ratio engines and methods for homogeneous charge, compression ignition operation. The engines effectively premix the fuel and air well before compression ignition. Various embodiments are disclosed including embodiments that include two stages of compression to obtain compression ratios well above the mechanical compression ratio of the engine cylinders for compression ignition of difficult to ignite fuels, and a controllable combustion chamber volume for limiting the maximum temperature during combustion. Energy storage with energy management are also disclosed.

A method for ascertaining whether a combustion process is being carried out in a cylinder of an internal combustion engine, it being decided whether or not the combustion process is present as a function of a relative angle between a characteristic signature of a variable characterizing a time curve of a state variable of the internal combustion engine and a specifiable crankshaft angle.

A method for engine control under an entire driving range of a vehicle based on control timing prediction implemented in the vehicle is provided, which may reduce a start angle error calculated at a calculation time prior to an operation time when actual injection and ignition is performed by grasping a tooth period change tendency for a tooth period of a current time that injector/igniter drivers of an engine control unit read from an engine position management driver and calculating a start angle of fuel injection and ignition through prediction of the tooth period to match an actual operation time. In particular, since the prediction of the tooth period to match the actual operation time is based on a change tendency of the tooth period stored up to the current time, the injection and ignition time effectively reflects an engine operation situation in which an engine RPM is changed.

A control device for an internal combustion engine includes an electronic control unit. The electronic control unit controls a fuel injection valve to inject at least primary fuel and secondary fuel in this order such that a pattern of a pressure increase rate in the combustion chamber includes a first peak and a second peak, controls an injection timing and an injection amount of each of the primary fuel and the secondary fuel such that a second peak value becomes higher than a first peak value, controls an intake device such that oxygen density is increased along with an increase in a load, and controls the injection timing and the injection amount of each of the primary fuel and the secondary fuel such that a peak difference acquired by subtracting the first peak value from the second peak value is increased as the load is increased.

A control system for a compression-ignition engine includes a combustion chamber, an injector, an ignition plug, a sensor device, and a controller having a circuitry. The ignition plug forcibly ignites mixture gas to start combustion accompanied by flame propagation of a part of the mixture gas, and again ignites remaining unburnt mixture gas at a timing at which the unburnt mixture gas combusts by self-ignition. The controller is configured to execute an ignition controlling module to output an ignition signal to the ignition plug before a target timing so that the unburnt mixture gas self-ignites at the target timing, an ignition timing estimating module to estimate an actual CI timing indicative of a timing at which the unburnt mixture gas actually self-ignited based on an in-cylinder pressure parameter, and an in-cylinder temperature determining module to determine the in-cylinder temperature at a given crank angle based on the estimated result.

A method is provided for visualizing a combustion process of a fuel-air mixture within a combustion chamber of an internal combustion engine. Flame light signals that are generated during the combustion of the fuel-air mixture within the combustion chamber are detected in a number of detection volumes (20) by a multi-channel optical measuring probe (2) and the light intensities of the flame light signals are evaluated and graphically visualized by an evaluating and visualizing device (5). Information concerning the position of the flame is provided by flame light signals within the detection volumes (20) and by the formation of hypotheses and by the selection of a most probable hypothesis by means of a mathematical assessment algorithm implemented in the evaluating and visualizing device (5) and are graphically visualized by the evaluating and visualizing device (5).