Abstract: An engine control system of a vehicle includes a cylinder control module configured to: determine a target sequence for at least activating and deactivating cylinders of an engine based on a torque request; and activate and deactivate the cylinders of the engine according to the target sequence. A values module is configured to determine, based on the target sequence, a plurality of coefficients and an offset value. An indicated mean effective pressure (IMEP) determination module is configured to determine an IMEP of a first cylinder based on: the plurality of coefficients; the offset value; and a plurality of engine speeds at a predetermined crankshaft positions, respectively.

Abstract: An engine control system of a vehicle includes a cylinder control module configured to: determine a target sequence for at least activating and deactivating cylinders of an engine based on a torque request; and activate and deactivate the cylinders of the engine according to the target sequence. A values module is configured to determine, based on the target sequence, a plurality of coefficients and an offset value. An indicated mean effective pressure (IMEP) determination module is configured to determine an IMEP of a first cylinder based on: the plurality of coefficients; the offset value; and a plurality of engine speeds at a predetermined crankshaft positions, respectively.

Abstract: A method, system, and engine are configured to determine a parameter based on rotational speeds of a crankshaft, over at least three cylinder combustion cycles. The method, system, and engine determine two or more estimated crankshaft rotational speeds at two or more positions in a leading cylinder combustion cycle, two or more estimated crankshaft rotational speeds at two or more positions in a middle cylinder combustion cycle, and two or more estimated crankshaft rotational speeds at two or more positions in a following cylinder combustion cycle. The method, system, and engine are configured to determine a calculated metric based on each of the determined leading estimated crankshaft rotational speeds, the determined middle estimated crankshaft rotational speeds, and the determined following estimated crankshaft rotational speeds. An engine parameter, such as misfire, is then determined based on the calculated metric.

Abstract: A method, system, and engine are configured to determine a parameter based on rotational speeds of a crankshaft, over at least three cylinder combustion cycles. The method, system, and engine determine two or more estimated crankshaft rotational speeds at two or more positions in a leading cylinder combustion cycle, two or more estimated crankshaft rotational speeds at two or more positions in a middle cylinder combustion cycle, and two or more estimated crankshaft rotational speeds at two or more positions in a following cylinder combustion cycle. The method, system, and engine are configured to determine a calculated metric based on each of the determined leading estimated crankshaft rotational speeds, the determined middle estimated crankshaft rotational speeds, and the determined following estimated crankshaft rotational speeds. An engine parameter, such as misfire, is then determined based on the calculated metric.

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 control system configured to control an internal combustion engine includes a crankshaft and an engine speed sensor. The crankshaft is rotated in response to combusting a mixture of air and fuel delivered to at least one cylinder included in the internal combustion engine. The engine output speed sensor is configured to output an engine output speed signal indicating a rotational speed of the crankshaft. An engine control module controls an amount of air and fuel delivered to the at least one cylinder and estimates a torque output based on the amount of air and fuel. A torque compensation module is configured to determine at least one weak cylinder based on the engine output speed signal. The torque compensation module is further configured to determine a torque compensation value that adjusts the estimated torque output based on the weak cylinder.

Abstract: A control system configured to control an internal combustion engine includes a crankshaft and an engine speed sensor. The crankshaft is rotated in response to combusting a mixture of air and fuel delivered to at least one cylinder included in the internal combustion engine. The engine output speed sensor is configured to output an engine output speed signal indicating a rotational speed of the crankshaft. An engine control module controls an amount of air and fuel delivered to the at least one cylinder and estimates a torque output based on the amount of air and fuel. A torque compensation module is configured to determine at least one weak cylinder based on the engine output speed signal. The torque compensation module is further configured to determine a torque compensation value that adjusts the estimated torque output based on the weak cylinder.

Abstract: A system for a vehicle includes a time stamping module, a period determination module, a stochastic pre-ignition (SPI) indication module, and an SPI remediation module. The time stamping module generates first and second timestamps when a crankshaft of an engine is in first and second crankshaft positions during an engine cycle, respectively. The period determination module determines a period between the first and second timestamps. The SPI indication module selectively indicates that an SPI event occurred within a cylinder of the engine based on the period. The SPI remediation module selectively adjusts at least one engine operating parameter in response to the SPI indication module indicating that the SPI event occurred within the cylinder.

Abstract: A system according to the principles of the present disclosure includes a threshold determination module and a misfire detection module. The threshold determination module determines at least one of an acceleration threshold and a jerk threshold based on a misfire type. The misfire detection module detects a misfire in a cylinder of an engine when: (i) crankshaft acceleration is less than the acceleration threshold; and/or (ii) crankshaft jerk is less than the jerk threshold. Crankshaft jerk is a derivative of crankshaft acceleration with respect to time.

Abstract: A system according to the principles of the present disclosure includes a threshold determination module and a misfire detection module. The threshold determination module determines at least one of an acceleration threshold and a jerk threshold based on a misfire type. The misfire detection module detects a misfire in a cylinder of an engine when: (i) crankshaft acceleration is less than the acceleration threshold; and/or (ii) crankshaft jerk is less than the jerk threshold. Crankshaft jerk is a derivative of crankshaft acceleration with respect to time.

Abstract: A fuel cell system that employs a method for determining the potential that a freeze condition will exist after the system is shut-down based on predetermined input, such as ambient temperature, geographical location, user usage profile, date, weather reports, etc. If the system determines that a freeze condition is probable, then the system initiates a purge shut-down of the fuel cell system where water is purged out of the reactant gas flow channels. If the system determines that a freeze condition is unlikely, then it will initiate a normal shut-down procedure without purging the flow channels. The system will then periodically determine if the conditions have changed, and will initiate the purge if a freeze condition subsequently becomes probable.

Abstract: A system for an engine includes first, second, third, and fourth modules. The first module determines an expected response of crankshaft speed due to combustion within a cylinder of the engine. The second module determines a value based on the expected response and a measured response of crankshaft speed due to combustion within the cylinder of the engine. The third module estimates an indicated mean effective pressure (IMEP) for the cylinder of the engine based on the value. The fourth module selectively adjusts an operating parameter of the engine based in the estimated IMEP.

Abstract: A control system includes an engine control module and a transmission control module. The transmission control module communicates with the engine control module via a network. The engine control module generates a mean engine speed signal and a minimum engine speed signal. The engine control module transmits the mean engine speed signal and the minimum engine speed signal to the transmission control module via the network. The transmission control module controls operation of at least one of a torque converter and a transmission based on the mean engine speed signal and the minimum engine speed signal. The torque converter is connected between an engine and the transmission.

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 time stamping module, a period determination module, a stochastic pre-ignition (SPI) indication module, and an SPI remediation module. The time stamping module generates first and second timestamps when a crankshaft of an engine is in first and second crankshaft positions during an engine cycle, respectively. The period determination module determines a period between the first and second timestamps. The SPI indication module selectively indicates that an SPI event occurred within a cylinder of the engine based on the period. The SPI remediation module selectively adjusts at least one engine operating parameter in response to the SPI indication module indicating that the SPI event occurred within the cylinder.

Abstract: A system for an engine includes first, second, third, and fourth modules. The first module determines an expected response of crankshaft speed due to combustion within a cylinder of the engine. The second module determines a value based on the expected response and a measured response of crankshaft speed due to combustion within the cylinder of the engine. The third module estimates an indicated mean effective pressure (IMEP) for the cylinder of the engine based on the value. The fourth module selectively adjusts an operating parameter of the engine based in the estimated IMEP.

Abstract: An engine control system includes a disturbance module, a torque correction module, a torque-to-spark module, and a spark correction module. The disturbance module determines a disturbance value for a past combustion stroke of a cylinder of an engine based on rotation of a crankshaft. The torque correction module selectively determines a torque correction for a future combustion stroke of the cylinder based on the disturbance value. The torque-to-spark module determines a spark correction based on the torque correction and determines an uncorrected spark timing based on a torque request. The spark correction module determines a corrected spark timing based on the uncorrected spark timing and the spark correction and generates spark during the future combustion stroke based on the corrected spark timing.

Abstract: A control module for a vehicle includes a time recording module that stores timestamps that correspond to each of N teeth of a target wheel of the vehicle in memory. N is an integer. A position module generates M angular positions based on the timestamps. M is an integer greater than one. Each of the M angular positions corresponds to a space between adjacent ones of the N teeth. A position estimator determines position of the target wheel based on the M positions.

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 control system includes an engine control module and a transmission control module. The transmission control module communicates with the engine control module via a network. The engine control module generates a mean engine speed signal and a minimum engine speed signal. The engine control module transmits the mean engine speed signal and the minimum engine speed signal to the transmission control module via the network. The transmission control module controls operation of at least one of a torque converter and a transmission based on the mean engine speed signal and the minimum engine speed signal. The torque converter is connected between an engine and the transmission.