Abstract: In one embodiment, a system includes an engine control system configured to control an engine. The engine control system comprises a processor configured to receive a vibration signal sensed by a knock sensor disposed in an engine. The processor is further configured to correlate the vibration signal with a fingerprint having at least an ADSR envelope indicative of the operating event of a valve train of the combustion engine, analyze the vibration signal with a statistical valve train model, or a combination thereof. The processor is also configured to detect if the operating event has occurred based on correlating of the noise signal with the fingerprint, based on analyzing the vibration signal with a statistical valve train model, or a combination thereof, and to control the valve train based on the operating event.

Abstract: A valve train for an internal combustion engine is provided. The valve train includes at least one rocker arm. The at least one rocker arm is mounted at a bearing. Further, the at least one rocker arm can be moved around the bearing by an actuating element. The valve train also includes at least one valve actuating element, wherein the at least one valve actuating element can be moved by the at least one rocker arm. At least one valve can be actuated by this movement of the at least one valve actuating element. A fluid element is arranged between the at least one valve actuating element and the at least one rocker arm. The fluid element comprises at least one cavity for a fluid. The volume of the fluid in the at least one cavity can be varied by moving a piston, and the at least one valve actuating element constitutes or is mounted on the piston.

Abstract: In one embodiment, a system includes an engine control system configured to control an engine. The engine control system comprises a processor configured to receive a vibration signal sensed by a knock sensor disposed in an engine. The processor is further configured to correlate the vibration signal with a fingerprint having at least an ADSR envelope indicative of the operating event of a valve train of the combustion engine, analyze the vibration signal with a statistical valve train model, or a combination thereof. The processor is also configured to detect if the operating event has occurred based on correlating of the noise signal with the fingerprint, based on analyzing the vibration signal with a statistical valve train model, or a combination thereof, and to control the valve train based on the operating event.

Abstract: In one embodiment, a system includes an engine control system configured to control an engine. The engine control system comprises a processor configured to receive a vibration signal sensed by a knock sensor disposed in an engine, and to receive a crankshaft signal sensed by a crank angle sensor disposed in the engine, wherein the crankshaft signal is representative of an engine crank angle. The processor is further configured to monitor a valve timing by deriving a cylinder head acceleration measurement via the vibration signal received by the knock sensor, wherein the processor is configured to monitor the valve timing by deriving a valve lash based on the vibration signal, the engine crank angle, and a threshold valve lash model.

Abstract: A system includes a camshaft disposed along an axis from a drive end to a opposite end, and the camshaft includes a plurality of journals configured to support the camshaft and is spaced along the axis. The camshaft includes a plurality of cams spaced along the axis, and is disposed along the camshaft in sets, where each set is disposed between a respective pair of journals of the plurality of journals. The camshaft includes a plurality of mass portions, where each mass portion is disposed between a set of cams and a respective journal. The plurality of mass portions is disposed along the camshaft such that a center of mass of the plurality of mass portions is nearer to the drive end than to the opposite end, and the plurality of mass portions is configured to increase a natural frequency of the shaft.

Abstract: A system includes a camshaft disposed along an axis from a drive end to a opposite end, and the camshaft includes a plurality of journals configured to support the camshaft and is spaced along the axis. The camshaft includes a plurality of cams spaced along the axis, and is disposed along the camshaft in sets, where each set is disposed between a respective pair of journals of the plurality of journals. The camshaft includes a plurality of mass portions, where each mass portion is disposed between a set of cams and a respective journal. The plurality of mass portions is disposed along the camshaft such that a center of mass of the plurality of mass portions is nearer to the drive end than to the opposite end, and the plurality of mass portions is configured to increase a natural frequency of the shaft.

Abstract: In one embodiment, a system includes an engine control system configured to control an engine. The engine control system comprises a processor configured to receive a vibration signal sensed by a knock sensor disposed in an engine, and to receive a crankshaft signal sensed by a crank angle sensor disposed in the engine, wherein the crankshaft signal is representative of an engine crank angle. The processor is further configured to monitor a valve timing by deriving a cylinder head acceleration measurement via the vibration signal received by the knock sensor, wherein the processor is configured to monitor the valve timing by deriving a valve lash based on the vibration signal, the engine crank angle, and a threshold valve lash model.