Abstract: A misfire detection system is provided including an internal combustion engine having a combustion chamber and an exhaust system in fluid communication with the combustion chamber. An acoustic sensor is associated with either the combustion chamber or the exhaust system for sensing noise. The controller receives a signal from the acoustic sensor for determining whether the noise is indicative of misfire. One or more acoustic sensors may be fluidly and/or mechanically coupled to the engine or other portion of the powertrain system. The acoustic sensor generates a signal having a frequency that may be compared to engine temperatures, speeds, and loads to determine whether a misfire event has occurred in one of the cylinders. The signature of the frequency may be determined and compared with a known set of frequencies for desired engine operation to determine whether a misfire has occurred.

Abstract: A particulate filter system is provided including an exhaust system transporting emissions from an engine. A filter such as a diesel particulate filter is disposed in the exhaust system. An acoustic sensor is associated with the exhaust system for detecting one or more frequencies passing through the filter. The frequency corresponds to a filter state indicative of a clean, full, loading, or failed filter. One or more acoustic sensors may fluidly or mechanically coupled to portions of the exhaust system to determine the frequency caused by the exhaust flow through the filter. The acoustic emissions from the filter may be used to compare to a known filter state to determine the present filter state. Alternatively, more sophisticated mathematical approaches may be used in which processed filter information is compared to a known filter state to determine the present filter state.

Abstract: A particulate filter system is provided including an exhaust system transporting emissions from an engine. A filter such as a diesel particulate filter is disposed in the exhaust system. An acoustic sensor is associated with the exhaust system for detecting one or more frequencies passing through the filter. The frequency corresponds to a filter state indicative of a clean, full, loading, or failed filter. One or more acoustic sensors may fluidly or mechanically coupled to portions of the exhaust system to determine the frequency caused by the exhaust flow through the filter. The acoustic emissions from the filter may be used to compare to a known filter state to determine the present filter state. Alternatively, more sophisticated mathematical approaches may be used in which processed filter information is compared to a known filter state to determine the present filter state.

Abstract: A misfire detection system is provided including an internal combustion engine having a combustion chamber and an exhaust system in fluid communication with the combustion chamber. An acoustic sensor is associated with either the combustion chamber or the exhaust system for sensing noise. The controller receives a signal from the acoustic sensor for determining whether the noise is indicative of misfire. One or more acoustic sensors may be fluidly and/or mechanically coupled to the engine or other portion of the powertrain system. The acoustic sensor generates a signal having a frequency that may be compared to engine temperatures, speeds, and loads to determine whether a misfire event has occurred in one of the cylinders. The signature of the frequency may be determined and compared with a known set of frequencies for desired engine operation to determine whether a misfire has occurred.