Systems, apparatuses, and methods of controlling an ignitor are disclosed. A method includes: receiving, by a controller, fuel quality data regarding a fuel for a spark-ignition engine; determining, by the controller, a fuel quality metric based on the fuel quality data; and controlling, by the controller, an ignition energy characteristic of an ignitor in response to the fuel quality metric.

A control apparatus for an internal combustion engine, includes circuitry. The circuitry is configured to control a ratio of an amount of low octane number fuel to be supplied to a cylinder to a total amount of the low octane number fuel and a high octane number fuel to be supplied to the cylinder in order to control an overall octane number of fuel to be supplied to the cylinder. The high octane number fuel has a second octane number higher than a first octane number of the low octane number fuel. The circuitry is configured to calculate a maximum octane number of the fuel to be supplied into the cylinder. The circuitry is configured to restrict a power generated by the internal combustion engine based on the maximum octane number.

Methods and systems are provided for injecting and combusting an amount of gaseous fuel during an exhaust stroke of a cylinder combustion event in order to reduce turbo lag and reduce a duration of time required for an exhaust catalyst to light-off during transient events. In one example, when an increase in torque demand is greater than a threshold, a first amount of gaseous fuel may be combusted during a compression stroke of a cylinder combustion event and a second amount of gaseous fuel may be combusted during an exhaust stroke of the combustion event. The second amount may be adjusted based on the increase in torque demand.

A method for controlling an internal combustion engine is disclosed. The method may include receiving knock data corresponding to knock levels over a time period. The method may also include determining from the knock data whether the knock levels change over the time period. Further, the method may include determining that a variation in the gas composition of the gaseous fuel supplied to the internal combustion engine has occurred when the knock levels change over the time period. In addition, the method may include adjusting an operating condition of the internal combustion engine to adapt a knock susceptibility of the internal combustion engine to the varying gas composition.

Methods and systems are provided for controlling fueling and mitigating knock in internal combustion engines, such as multi-fuel engines. In one example, a method may include monitoring a frequency of knock events corresponding to one or more engine cylinders, and dynamically increasing a substitution ratio while the frequency of knock events is less than a maximum action threshold. In some examples, the method may further include actively adjusting one or more engine operating conditions to decrease the substitution ratio responsive to a severity of knocking in the one or more engine cylinders being greater than or equal to a threshold severity.

An ignition timing controller includes a storage and a processor configured or programmed to function as an ignition timing control section and a knocking determining section. The storage stores at least one of a first ignition timing map associated with a first fuel or a second ignition timing map associated with a second fuel more likely to cause knocking of an internal combustion engine than the first fuel. The ignition timing control section controls the ignition timing based on the first ignition timing map by executing a timing retardation based on the first ignition timing map when it is determined that knocking of the internal combustion engine has occurred. The ignition timing control section controls the ignition timing of the internal combustion engine based on the second ignition timing map by executing a timing advancement correction based on the second ignition timing map when it is determined that the knocking of the internal combustion engine has not occurred.

A method of controlling an ignitor for a spark-ignition engine includes receiving, by a controller, at least one of fuel quality data regarding a fuel for the spark-ignition engine or a characteristic regarding the ignitor for the spark-ignition engine. The method additionally includes controlling, by the controller, an ignition energy characteristic of the ignitor in response to the at least one of the fuel quality data regarding the fuel or the characteristic regarding the ignitor for the spark-ignition engine.

A method of controlling an ignitor for a spark-ignition engine includes receiving, by a controller, at least one of fuel quality data regarding a fuel for the spark-ignition engine or a characteristic regarding the ignitor for the spark-ignition engine. The method additionally includes controlling, by the controller, an ignition energy characteristic of the ignitor in response to the at least one of the fuel quality data regarding the fuel or the characteristic regarding the ignitor for the spark-ignition engine.

According to one or more embodiments, an internal combustion engine may be operated by a method which includes one or more of passing a first fuel and a second fuel into an engine cylinder to form a fuel mixture, and combusting the fuel mixture with a spark plug to translate a piston housed in the engine cylinder and rotate a crank shaft coupled to the piston. The first fuel may comprise a greater octane rating than the second fuel. A target CA50 may correspond to a minimum in specific fuel consumption of the fuel mixture. The spark plug may initiate combustion at a time such that the internal combustion engine operates with an operational CA50 that is within 20 degrees of the target CA50.

A CPU mounted on a vehicle obtains positional data by the GPS. Next, the CPU identifies an octane number, which is a parameter related to combustion of fuel, on the basis of the positional data corresponding to the position of the vehicle and the date and time at which the positional data was obtained. Then, the CPU calculates a correction amount on the basis of the identified parameter. The CPU assigns, to ignition timing, a value calculated on the basis of the correction amount. The CPU controls an ignition device so that the ignition device generates spark discharge at the calculated ignition timing.