A method for determining the wear rate of a spark plug electrode of an ignition system of an internal combustion engine comprises determining a risetiine number indicating the time required for raising the current and thereby the primary energy which is supplied to an ignition coil of the spark plug from an inactive level to a predetermined level, determining an operating condition indicator configured to indicate an operating condition of the ignition system, determining a wear rate of the spark plug electrode based on a difference of a first spark plug state indicator at a first time instance and a second spark plug state indicator at a second time instance, wherein the first time instance and the second time instance are separated by a predetermined time interval, wherein the spark plug state indicator is determined as a value based on the risetime number and the operating condition indicator.

A method for determining the wear rate of a spark plug electrode of an ignition system of an internal combustion engine comprises determining a risetiine number indicating the time required for raising the current and thereby the primary energy which is supplied to an ignition coil of the spark plug from an inactive level to a predetermined level, determining an operating condition indicator configured to indicate an operating condition of the ignition system, determining a wear rate of the spark plug electrode based on a difference of a first spark plug state indicator at a first time instance and a second spark plug state indicator at a second time instance, wherein the first time instance and the second time instance are separated by a predetermined time interval, wherein the spark plug state indicator is determined as a value based on the risetime number and the operating condition indicator.

An ignition system for an internal combustion engine includes an ignition coil forming a part of a primary circuit and a secondary circuit, a power source to supply power to the ignition coil, and a controller to determine whether the ignition coil is a recognized ignition coil based on a measured risetime and a measured current level in the primary circuit, the measured current level being lower than that required to create a breakdown voltage of the ignition coil.

An ignition system for an internal combustion engine includes an ignition coil forming a part of a primary circuit and a secondary circuit, a power source to supply power to the ignition coil, and a controller to determine whether the ignition coil is a recognized ignition coil based on a measured risetime and a measured current level in the primary circuit, the measured current level being lower than that required to create a breakdown voltage of the ignition coil.

Methods and systems are provided for determining an ignition coil dwell time based on an estimated ignition coil temperature. In one example, a method may include estimating the ignition coil temperature based on heat transfer between engine and the ignition coil, heat transfer between ambient and the ignition coil, and internal resistive heating of the ignition coil.

A method for determining the wear rate of a spark plug electrode of an ignition system of an internal combustion engine comprises determining a risetiine number indicating the time required for raising the current and thereby the primary energy which is supplied to an ignition coil of the spark plug from an inactive level to a predetermined level, determining an operating condition indicator configured to indicate an operating condition of the ignition system, determining a wear rate of the spark plug electrode based on a difference of a first spark plug state indicator at a first time instance and a second spark plug state indicator at a second time instance, wherein the first time instance and the second time instance are separated by a predetermined time interval, wherein the spark plug state indicator is determined as a value based on the risetime number and the operating condition indicator.

A method for determining the wear rate of a spark plug electrode of an ignition system of an internal combustion engine comprises determining a risetiine number indicating the time required for raising the current and thereby the primary energy which is supplied to an ignition coil of the spark plug from an inactive level to a predetermined level, determining an operating condition indicator configured to indicate an operating condition of the ignition system, determining a wear rate of the spark plug electrode based on a difference of a first spark plug state indicator at a first time instance and a second spark plug state indicator at a second time instance, wherein the first time instance and the second time instance are separated by a predetermined time interval, wherein the spark plug state indicator is determined as a value based on the risetime number and the operating condition indicator.

The subject matter of this specification can be embodied in, among other things, a method that includes receiving a collection of measurements of electric current amplitude in a primary winding of an engine ignition system having the primary winding and a spark plug, identifying an ignition start time, identifying an inflection point based on the plurality of measurements, determining an inflection point time representative of a time at which the identified inflection point occurred, determining a spark start time based on an amount of time between the ignition start time and the inflection point time, and providing a signal indicative of the spark start time.

The subject matter of this specification can be embodied in, among other things, a method that includes receiving a collection of measurements of electric current amplitude in a primary winding of an engine ignition system having the primary winding and a spark plug, identifying an ignition start time, identifying an inflection point based on the plurality of measurements, determining an inflection point time representative of a time at which the identified inflection point occurred, determining a spark start time based on an amount of time between the ignition start time and the inflection point time, and providing a signal indicative of the spark start time.

A controller for a spark plug of an engine is provided. The controller is configured to receive a signal indicative of an operational parameter of the engine. The controller is configured to define a breakdown time duration for the spark plug. Further, the controller is configured to determine an optimum amount of energy required to generate a spark for the spark plug based on the defined breakdown time duration and the operational parameter. The controller is further configured to cause the optimum amount of energy to be supplied to the spark plug to cause the spark to be generated for the spark plug.