Abstract: An engine control system includes: a normalization module configured to normalize, to within a predetermined range of values, a spark timing of an engine and at least one other parameter of the engine, thereby producing a normalized spark timing and at least one normalized other parameter, respectively; a processing module configured to generate a sigmoidal spark timing by applying, to the normalized spark timing, one of (a) a sigmoidal function and a sinusoidal function; and an estimation module configured to estimate a torque output of the engine based on the normalized spark timing and the at least one normalized other parameter using a mathematical model.

Abstract: An engine control system includes: a normalization module configured to normalize, to within a predetermined range of values, a spark timing of an engine and at least one other parameter of the engine, thereby producing a normalized spark timing and at least one normalized other parameter, respectively; a processing module configured to generate a sigmoidal spark timing by applying, to the normalized spark timing, one of (a) a sigmoidal function and a sinusoidal function; and an estimation module configured to estimate a torque output of the engine based on the normalized spark timing and the at least one normalized other parameter using a mathematical model.

Abstract: A system for a vehicle includes a filtering module and an indicated work module. The filtering module generates engine speeds based on positions of teeth of a toothed wheel that rotates with a crankshaft and based on a crankshaft position signal generated by a crankshaft position sensor. The crankshaft position sensor generates the crankshaft position signal based on rotation of the toothed wheel. The indicated work module generates an indicated work for a combustion cycle of a cylinder of an engine based on squares of first and second ones of the engine speeds and outputs the indicated work.

Abstract: A system according to the principles of the present disclosure includes a misfire detection module and a fuel control module. The misfire detection module detects misfire in a cylinder of an engine. The fuel control module controls a first fuel system to deliver a first fuel to the cylinder and controls a second fuel system to deliver a second fuel to the cylinder. The first fuel and the second fuel are different types of fuel. The fuel control module selectively switches from delivering the first fuel to the cylinder to delivering the second fuel to the cylinder when misfire is detected in the cylinder.

Abstract: A fuel control module, based on an engine torque request, fuels N cylinders of an engine using a first fuel system. N is an integer greater than zero. A throttle control module, based on the engine torque request and the fueling of the N cylinders using the first fuel system, opens a throttle valve to a predetermined wide open throttle (WOT) position. A cost module, when the engine torque request is greater than a predetermined torque: determines a first cost value for fueling at least one of the N cylinders of the engine using a second fuel system; and determines a second cost value for adjusting at least one operating parameter other than fueling of the engine. An adjustment module, based on, the first and second cost values, one of: initiates the fueling of the at least one of the N cylinders using the second fuel system; and adjusts of the at least one operating parameter other than fueling of the engine.

Abstract: A fuel control module, based on an engine torque request, fuels N cylinders of an engine using a first fuel system. N is an integer greater than zero. A throttle control module, based on the engine torque request and the fueling of the N cylinders using the first fuel system, opens a throttle valve to a predetermined wide open throttle (WOT) position. A cost module, when the engine torque request is greater than a predetermined torque: determines a first cost value for fueling at least one of the N cylinders of the engine using a second fuel system; and determines a second cost value for adjusting at least one operating parameter other than fueling of the engine. An adjustment module, based on, the first and second cost values, one of: initiates the fueling of the at least one of the N cylinders using the second fuel system; and adjusts of the at least one operating parameter other than fueling of the engine.

Abstract: A system according to the principles of the present disclosure includes a misfire detection module and a fuel control module. The misfire detection module detects misfire in a cylinder of an engine. The fuel control module controls a first fuel system to deliver a first fuel to the cylinder and controls a second fuel system to deliver a second fuel to the cylinder. The first fuel and the second fuel are different types of fuel. The fuel control module selectively switches from delivering the first fuel to the cylinder to delivering the second fuel to the cylinder when misfire is detected in the cylinder.

Abstract: A control system for a vehicle includes a time determination module, a fuel age determination module, and an engine control module. The time determination module determines an engine off time, wherein the engine off time indicates an amount of time that an engine is off. The fuel age determination module determines an age of fuel in a fuel system of the engine. The engine control module starts the engine when one of the engine off time is greater than a predetermined time threshold and the age of the fuel is greater than a predetermined age threshold.

Abstract: An engine control system includes a disturbance module, a misfire threshold determination module, a disturbance ratio module, and a spark control module. The disturbance module determines a disturbance value for a past combustion stroke of a cylinder based on rotation of a crankshaft. The misfire threshold determination module determines a jerk value indicative of a misfire within the cylinder. The disturbance ratio module determines a disturbance ratio for the past combustion stroke based on the disturbance value and the jerk value. The spark control module determines a spark timing for a future combustion stroke of the cylinder, determines a spark timing correction for the future combustion stroke based on the disturbance ratio, determines a corrected spark timing based on the spark timing and the spark timing correction, and generates spark during the future combustion stroke based on the corrected spark timing.

Abstract: A system for a vehicle includes a filtering module and an indicated work module. The filtering module generates engine speeds based on positions of teeth of a toothed wheel that rotates with a crankshaft and based on a crankshaft position signal generated by a crankshaft position sensor. The crankshaft position sensor generates the crankshaft position signal based on rotation of the toothed wheel. The indicated work module generates an indicated work for a combustion cycle of a cylinder of an engine based on squares of first and second ones of the engine speeds and outputs the indicated work.

Abstract: An engine control system includes a disturbance module, a misfire threshold determination module, a disturbance ratio module, and a spark control module. The disturbance module determines a disturbance value for a past combustion stroke of a cylinder based on rotation of a crankshaft. The misfire threshold determination module determines a jerk value indicative of a misfire within the cylinder. The disturbance ratio module determines a disturbance ratio for the past combustion stroke based on the disturbance value and the jerk value. The spark control module determines a spark timing for a future combustion stroke of the cylinder, determines a spark timing correction for the future combustion stroke based on the disturbance ratio, determines a corrected spark timing based on the spark timing and the spark timing correction, and generates spark during the future combustion stroke based on the corrected spark timing.

Abstract: A control system includes a jerk determination module and a misfire confirmation module. The jerk determination module determines a jerk of a crankshaft associated with a firing event in an engine. The misfire confirmation module selectively confirms that a misfire detected in the engine is valid based on the jerk.

Abstract: An engine misfire system comprises a rough road detection module and a misfire detection module. The rough road detection module selectively generates a rough road indicator based upon a transmission output speed of a vehicle. The misfire detection module selectively diagnoses engine misfire and selectively generates a misfire indicator based on diagnosed engine misfire and the rough road indicator.

Abstract: A control system for a vehicle includes a time determination module, a fuel age determination module, and an engine control module. The time determination module determines an engine off time, wherein the engine off time indicates an amount of time that an engine is off. The fuel age determination module determines an age of fuel in a fuel system of the engine. The engine control module starts the engine when one of the engine off time is greater than a predetermined time threshold and the age of the fuel is greater than a predetermined age threshold.

Abstract: A control system includes a jerk determination module and a misfire confirmation module. The jerk determination module determines a jerk of a crankshaft associated with a firing event in an engine. The misfire confirmation module selectively confirms that a misfire detected in the engine is valid based on the jerk.

Abstract: An engine system that compensates for disturbances in a crankshaft signal is provided. The system includes: an error module that computes an error between an ideal period and an actual period of a crankshaft signal; a correction factor module that determines a correction factor based on the error; and a compensation module that applies the correction factor to the actual period of the crankshaft signal.

Abstract: An engine misfire system comprises a rough road detection module and a misfire detection module. The rough road detection module selectively generates a rough road indicator based upon a transmission output speed of a vehicle. The misfire detection module selectively diagnoses engine misfire and selectively generates a misfire indicator based on diagnosed engine misfire and the rough road indicator.

Abstract: The present invention generally includes a method of detecting a misfire in an internal combustion engine. The method includes detecting a first engine speed at a first crankshaft position that corresponds to about a top dead center compression position of a first piston within a first cylinder and detecting a second engine speed at a second crankshaft position that corresponds to about a position subsequent to the top dead center compression position. The method determines whether the misfire occurred in the first cylinder based on the first engine speed and the second engine speed. The method provides an improved signal to noise ratio for engine misfire detection.

Abstract: An engine system that compensates for disturbances in a crankshaft signal is provided. The system includes: an error module that computes an error between an ideal period and an actual period of a crankshaft signal; a correction factor module that determines a correction factor based on the error; and a compensation module that applies the correction factor to the actual period of the crankshaft signal.

Abstract: A rough road detection system for an engine having a crankshaft includes a control module and a comparison module. The control module receives a crankshaft speed signal and determines a crankshaft rotation time and a crankshaft acceleration and jerk. The crankshaft rotation time is based on said crankshaft speed signal. The crankshaft acceleration and jerk are based on said crankshaft rotation time. The control module detects a crankshaft disturbance based on said crankshaft acceleration and jerk and counts a number of crankshaft disturbances. The comparison module determines a dispersion value and asymmetry value based on the crankshaft disturbances and determined whether rough road conditions exist based on first and second comparisons. The first comparison is between the dispersion value and a first predetermined threshold. The second comparison is between the asymmetry value and a second predetermined threshold.