Methods and systems are provided for restarting an engine following an engine idle-stop. In one example, a method may include, prior to an engine restart following an idle-stop, adjusting a spark ignition timing based on an estimation of a fuel-air equivalence ratio (phi) and an estimation of a cylinder turbulence. Optimal spark ignition timing based on estimated phi and cylinder turbulence during engine restart may result in stabilized combustion and a torque output sufficient to at least partially relieve demand on the starting device.

One embodiment is a system comprising an engine including a dedicated EGR cylinder configured to provide EGR to the engine via an EGR loop, a non-dedicated cylinder, a plurality of injectors, an ignition system including a plurality of spark plugs, an intake throttle, and an electronic control system. The electronic control system is configured to control combustion during transient operation of the engine by determining one or more combustion control parameters compensating for variation of one or more of inert matter, unburned air and unburned fuel in EGR output by the dedicated EGR cylinder during transient operation of the engine, and an effect of the EGR loop on inert matter, unburned air and unburned fuel provided to the plurality of cylinders, and controlling operation of at least one of the throttle, the ignition system and the plurality of injectors in response to at least one of the one or more combustion control parameters.

Provided is a control device and a control method of a high-efficiency internal combustion engine capable of stabilizing combustion and suppressing NO.sub.x emissions without unnecessarily increasing a mounting load on an ECU. Therefore, the control device of the internal combustion engine for controlling the internal combustion engine includes an ignition plug that ignites an air-fuel mixture of fuel and air in the combustion chamber, a combustion pressure estimation sensor that detects a combustion pressure in the combustion chamber, and a crank angle sensor that detects a crank angle of a crankshaft. An MBT region is set based on an ignition delay period from an ignition timing of the ignition plug calculated from a detection value of the combustion pressure estimation sensor and a detection value of the crank angle sensor to a combustion start timing in the combustion chamber, and a combustion period from the combustion start timing to a set amount combustion end timing when a set amount of combustion ends. An ignition timing of the ignition plug is controlled so as to fall within the set MBT region.

A method for operating a combustion engine is disclosed. In an embodiment, the method includes: generating several sparks to ignite a fuel-air mixture in a combustion chamber by an ignition device of the combustion engine, determining a combustion duration of at least one of the sparks, detecting a deviation of an actual operation from a target operation of the combustion engine at least depending on the combustion duration, compensating for the deviation by implementing at least one measure which influences a combustion of the fuel-air mixture in the combustion chamber, determining the combustion duration of the chronological first of the sparks, allocating the first spark to a first spark type or to a second spark type depending on the combustion duration, and implementing the at least one measure if at least one value which characterizes a frequency of one of the spark types exceeds a threshold value.

A method for operating a combustion engine is disclosed. In an embodiment, the method includes: generating several sparks to ignite a fuel-air mixture in a combustion chamber by an ignition device of the combustion engine, determining a combustion duration of at least one of the sparks, detecting a deviation of an actual operation from a target operation of the combustion engine at least depending on the combustion duration, compensating for the deviation by implementing at least one measure which influences a combustion of the fuel-air mixture in the combustion chamber, determining the combustion duration of the chronological first of the sparks, allocating the first spark to a first spark type or to a second spark type depending on the combustion duration, and implementing the at least one measure if at least one value which characterizes a frequency of one of the spark types exceeds a threshold value.

A small-size injector having a built-in ignition device which can surely inject fuel and ignite the fuel with low electric power by the ignition device with a simple configuration is provided. The injector comprises a fuel injecting device 2 provided with a fuel injecting port 20 configured to inject the fuel, an ignition device 3 configured to ignite the injected fuel, and a casing 10 inside housing therein the fuel injecting device 2 and the ignition device 3 together. The ignition device 3 is constituted of a plasma generator 3 which integrally comprises a booster 5 having a resonation structure capacity-coupled with an electromagnetic wave oscillator MW configured to oscillate an electromagnetic wave, and a discharger 6 configured to cause a discharge of a high voltage generated by the booster 5.

A small-size injector having a built-in ignition device which can surely inject fuel and ignite the fuel with low electric power by the ignition device with a simple configuration is provided. The injector comprises a fuel injecting device 2 provided with a fuel injecting port 20 configured to inject the fuel, an ignition device 3 configured to ignite the injected fuel, and a casing 10 inside housing therein the fuel injecting device 2 and the ignition device 3 together. The ignition device 3 is constituted of a plasma generator 3 which integrally comprises a booster 5 having a resonation structure capacity-coupled with an electromagnetic wave oscillator MW configured to oscillate an electromagnetic wave, and a discharger 6 configured to cause a discharge of a high voltage generated by the booster 5.

A system according to the principles of the present disclosure includes a vibration prediction module and a firing sequence module. The vibration prediction module predicts a modal response of a vehicle based on a firing sequence of an engine when a cylinder of the engine is deactivated. The firing sequence module adjusts the firing sequence of the engine based on the predicted modal response of the vehicle.

A variety of methods and arrangements for implementing a start/stop feature in a skip fire engine control system are described. In one aspect, the implementation of the start/stop feature involves automatically turning off an internal combustion engine under selected circumstances during a drive cycle. A determination is made that the engine should be restarted. During the engine startup period, the engine is operated in a skip fire manner such that a desired engine speed is reached.

An ignition coil unit includes: an ignition circuit including a primary coil and a secondary coil; a power generator including a generator coil; a controller configured to control an ignition timing of the ignition circuit by an input signal generated by an induced voltage of the generator coil; and a sensor configured to input load information to the controller. The controller includes a memory configured to store working time information which corresponds to operating information based on the input information and the load information, as matrix data composed of the operating information, the load information and time data.