摘要:
A method and system of misfire determination includes establishing an acceleration misfire threshold and an acceleration sub-misfire threshold. Then incremental engine position is sensed and a series of acceleration data-points are derived (401). If a data-point of the series of acceleration data-points falls between the sub-misfire threshold and the misfire threshold, then a training process is aborted for a blanking period based on a delay time whose length is preferably based on engine operating conditions (415). If a data-point of the series of acceleration data-points does not fall below the sub-misfire threshold, then the series of acceleration data-points, are averaged and a synchronously corrected acceleration data-point is derived (417). Then, a misfire condition is indicated when the synchronously corrected acceleration data-point exceeds the established acceleration misfire threshold (421).
摘要:
A method for monitoring the performance of a catalytic converter (34) computes the oxygen storage capacity and desorption capacity of a catalyst within the catalytic converter (34). An engine control unit (10) receives mass flow rate information of air from a mass air flow rate sensor (12) and an injector driver (24), and receives electrical signals from an upstream exhaust gas sensor (28) and a downstream exhaust gas sensor (30). A rate modifier is determined from excess air ratios and an adaptation parameter. The engine control unit (10) calculates normalized air fuel ratios for the exhaust gas entering and leaving the catalytic converter (34) and performs numerical integration using the rate modifier to determine the oxygen storage capacity of the catalyst in the catalytic converter (34). The calculated oxygen storage capacity of the catalyst can be compared with threshold values to determine the performance of the catalytic converter (34).
摘要:
A method of operating an engine includes determining at least one characteristic of rough road performance based on at least one driveline characteristic and receiving crankshaft acceleration data. The method further includes comparing the received crankshaft acceleration data and determined characteristic, inhibiting the misfire counter based on the comparison, and operating the engine based on the disabled misfire detection.
摘要:
A method for determining a misfire condition includes receiving crankshaft acceleration data. The method further includes routing the received data through at least one of a plurality of processing paths and through a startup path and determining a crankshaft revolution count. The method further includes comparing the determined crankshaft accelerations over the determined revolution count to at least one threshold crankshaft acceleration value over the determined revolution count and determining a misfire condition from one of the startup path and the processing path based on the comparison.
摘要:
A method for determining a misfire condition includes receiving crankshaft acceleration data. The method further includes routing the received data through at least one of a plurality of processing paths and through a startup path and determining a crankshaft revolution count. The method further includes comparing the determined crankshaft accelerations over the determined revolution count to at least one threshold crankshaft acceleration value over the determined revolution count and determining a misfire condition from one of the startup path and the processing path based on the comparison.
摘要:
A method and system for identifying a phase in an internal combustion engine (102) is disclosed. The internal combustion engine may include an even number of cylinders and is fitted with at least one sensor. In one embodiment, the method includes measuring a state of the internal combustion engine using the at least one sensor. The method may further include calculating a deviation of the state from an expected set of values, and determining the phase of the internal combustion engine, based on the deviation.
摘要:
A method of operating an engine includes determining at least one characteristic of rough road performance based on at least one driveline characteristic and receiving crankshaft acceleration data. The method further includes comparing the received crankshaft acceleration data and determined characteristic, inhibiting the misfire counter based on the comparison, and operating the engine based on the disabled misfire detection.
摘要:
A method and apparatus converts time-resolved sensor signals into transfer functions and/or cumulative transfer function signals which can be attained by computation means such as by using Fast Fourier Transforms. A signal, as a means to assess catalyst performance such as a signal based on sensing oxygen concentration or air to fuel ratio or hydrocarbon concentration in motor vehicle exhaust in accordance with the present invention is in the time domain and has multiple components at different frequencies. The use of Fast Fourier Transforms isolates the various spectral densities which arise from different frequency components of the complex time domain signal. Cross spectral density function and power spectral density function are used to determine the transfer function. The analysis has been found to be substantially independent of operating conditions. The transfer function and cumulative transfer function have been found to be a precise indication of the catalyst performance. The catalyst performance can be signaled to the vehicle operator for on board diagnostics (OBD) of the catalyst.