A controller performs a rotation angle deriving process that derives a value of the rotation angle of a crankshaft by each specified angle that is smaller than a predetermined angle by performing a Hilbert process on a detection signal from a crankshaft sensor, an angular velocity deriving process that derives an angular velocity of the crankshaft as an engine angular velocity from the value of the rotation angle of the crankshaft by each specified angle, an inertia torque calculation process that calculates an engine inertia torque from the engine angular velocity, a resonance effect torque calculation process that calculates a resonance effect torque, and an engine torque calculation process that calculates a sum of the resonance effect torque and the engine inertia torque as an engine torque that is an output torque of the engine.

An engine unit controller (EUC) in connection with a hybrid opposed piston engine can receive real-time movement data of a crankshaft via a crank position sensor. It can simultaneously receive current data of an electric motor that partially controls the crankshaft. With the known engine constants, the EUC can determine instantaneous combustion pressure data based on the movement data and the current data. Such combustion pressure data can be used to optimize the engine's performance in real-time.

In an engine having fuel supply means for supplying fuel containing gasoline to a combustion chamber and ignition means for igniting an air-fuel mixture, if knocking occurs when ignition is performed at a reference ignition timing set on a retarded side of MBT that is an ignition timing at which the engine torque is maximized in a high-load region in which the engine load is larger than a predetermined load, ignition advance control that causes the ignition means to perform ignition at a timing on an advanced side of the reference ignition timing is performed.

Methods and systems are provided for operating a cylinder with a series gap igniter coupled to an ion sensing module. In one example, a method may include determining a location of an initial combustion in a cylinder from a series gap igniter based on a pressure rise rate in the cylinder, the ignition spark initiating combustion in the cylinder; and adjusting at least one setting of the cylinder based on the determined location. In this way, combustion stability and efficiency may be increased without increasing a cost and complexity of the engine.

Methods and systems are provided for controlling and monitoring intake and exhaust poppet valves of an internal combustion engine. In one example, the methods and system include feedback control that estimates intake and exhaust valve timing based on output of an in cylinder pressure sensor. In another example, the methods and system include compensation for feedforward control of intake and exhaust valves based on output of the in cylinder pressure sensor.

A variety of methods and arrangements are described for managing recharging of cylinders of an internal combustion engine during skip fire operation of the engine. In one method, a maximum allowed deactivation time for a cylinder is determined and the cylinder is recharged before the maximum allowed deactivation time is exceeded.

Disclosed herein is a method of predicting engine knocking, which includes calculating initial pressure in cylinder based on operating data and pressure in intake manifold measured using manifold absolute pressure sensor, calculating pressure at spark timing in the cylinder by interpreting compression process as polytropic process based on the calculated initial pressure in the cylinder, calculating heat release rate for individual operating conditions based on the calculated pressure in the cylinder at spark timing, calculating pressure change in the cylinder based on the calculated heat release rate, calculating unburned gas temperature in adiabatic compression process based on the calculated pressure change in the cylinder, and determining whether knock occurs by calculating ignition delay based on the calculated unburned gas temperature and calculating unburned gas mass fraction at crank angle at the end of the ignition delay.

Various embodiments of the present disclosure are directed towards free-piston combustion engines. As described herein, a method and system are provided for displacing a free-piston assembly to achieve a desired engine performance by repeatedly determining position-force trajectories over the course of a propagation path and effecting the displacement of the free-piston assembly based, at least in part, on the position-force trajectory. In a dual-piston assembly free-piston engine, synchronization of the two piston assemblies is provided.

A method for monitoring a cylinder pressure sensor, in which method the sensor value is checked for admissibility and inadmissibility in a predefinable crankshaft angle range, when admissibility is detected the cylinder pressure sensor is used further and when inadmissibility is detected the cylinder pressure sensor is deactivated. A first sensor value of the cylinder pressure sensor is set as a start value, and a second sensor value is set as a stop value, a plateau range is determined from the number of sampling steps between the start value and the stop value, and the plateau range is set as decisive for the admissibility or inadmissibility of the sensor values.

An object of the present invention is to provide a control device of an injector capable of suppressing the influence of pressure reduction boiling even if pressure in a combustion chamber is low. In a case where the temperature of fuel injected from a fuel injection valve is within a set high temperature region and the pressure of the combustion chamber is within a set low pressure region, the control device of an in-cylinder direct injection-type injector according to the present invention controls to increase a lift amount of the injector as compared to the case of a low temperature region or a high pressure region.