초록 ▼

A method/system for measuring cylinder pressures of an internal combustion engine includes a crank angle sensor utilized to generate pressure readings at known angular intervals. Additional time-based pressure measurements are taken in selected angular windows between a pair of the angle-based press

A method/system for measuring cylinder pressures of an internal combustion engine includes a crank angle sensor utilized to generate pressure readings at known angular intervals. Additional time-based pressure measurements are taken in selected angular windows between a pair of the angle-based pressure readings. Because the angle-based pressure measurements and the time-based pressure measurements occur at known times, the pressure as a function of the crank angle for the time-based pressure measurements can be determined. The cylinder pressure measurements can be utilized to calculate combustion parameters used for closed-loop engine control of fuel supply or other engine inputs.

대표청구항 ▼

The invention claimed is: 1. A method of determining cylinder pressure in internal-combustion engines, the method comprising: providing an angular position sensor capable of determining an angular position of a rotating engine component; generating a plurality of angle-based time stamps, each angle

The invention claimed is: 1. A method of determining cylinder pressure in internal-combustion engines, the method comprising: providing an angular position sensor capable of determining an angular position of a rotating engine component; generating a plurality of angle-based time stamps, each angle-based time stamp comprising an angular position of the rotating engine component and a time value associated with the angular position; providing at least one sensor capable of determining a cylinder pressure in an internal combustion engine; generating a plurality of time-based pressure stamps by measuring a cylinder pressure at a plurality of predetermined time intervals, each time-based pressure stamp comprising a cylinder pressure and a time value associated with the cylinder pressure; utilizing the angle-based time stamps and the time-based pressure stamps to determine cylinder pressures at associated angular positions. 2. The method of claim 1, wherein: at least two of the angle-based time stamps define a first time interval between the time stamps; the predetermined time intervals are substantially smaller than the first time interval. 3. The method of claim 1, wherein: the angle-based time stamps are generated by measuring the angular position at equal angular displacements. 4. The method of claim 3, wherein: the angular position sensor has a maximum resolution of at least about six degrees, and the angle-based time stamps are generated at the maximum resolution of the angular position sensor. 5. The method of claim 1, wherein: the time-based pressure stamps are not utilized to determine cylinder pressures between at least one adjacent pair of the angle-based time stamps. 6. The method of claim 5, wherein: the rotating engine component rotates through a predetermined angular displacement for each complete cycle of the internal combustion engine; and wherein: the cylinder pressure is only measured at the angle-based time stamps during a substantial portion of the predetermined angular displacement. 7. The method of claim 1, including: measuring cylinder pressure at the angle-based time stamps to provide pressure sampling having a first resolution during portions of the cycle wherein the cylinder pressure is substantially constant relative to cylinder pressure variations during a combustion event. 8. The method of claim 7, wherein: a plurality of time-based pressure stamps are taken between at least a selected pair of angle-based time stamps during a combustion event to provide a second pressure sampling that is substantially higher resolution than the first resolution. 9. The method of claim 8, wherein: the time-based pressure stamps are taken over a crankshaft rotation angle of at least about six degrees. 10. The method of claim 8, wherein: the time-based pressure stamps are taken over a crankshaft rotation angle of at least about sixty degrees. 11. The method of claim 1, including: determining at least one combustion-related engine operating parameter utilizing the time-based pressure stamps. 12. The method of claim 11, wherein: the operating parameter is selected from the group consisting of indicated mean effective pressure, start of combustion, and location of peak pressure. 13. The method of claim 11, including: controlling an input to the engine based, at least in part, on the at least one combustion-related engine operating parameter. 14. The method of claim 1, wherein: the time-based pressure stamps are taken at a resolution of at least about one degree of crankshaft rotation. 15. A method of controlling an internal combustion engine of the type having a crankshaft that rotates seven hundred and twenty degrees during each engine cycle, the method comprising: measuring cylinder pressure of a cylinder at a plurality of crankshaft rotation angles to generate a first set of angle-based cylinder pressure readings at known crankshaft rotation angles at a first angular resolution; measuring cylinder pressure of the cylinder at a plurality of points between at least a selected pair of the angle-based cylinder pressure readings during a combustion event to generate a second set of cylinder pressure readings having a second angular resolution that is substantially greater than the first angular resolution; utilizing at least some of the cylinder pressure readings in the vicinity of a combustion event to determine a combustion-related engine operating parameter; controlling operation of the internal combustion engine based, at least in part, upon the combustion-related engine operating parameter. 16. The method of controlling an internal combustion engine of claim 15, wherein: the second set of cylinder pressure readings are taken at preselected time intervals that are sufficiently small to ensure that a plurality of pressure readings are taken between an adjacent pair of the angle-based pressure readings. 17. The method of controlling an internal combustion engine of claim 15, wherein: the second set of cylinder pressure readings are only generated over a user-defined range, wherein the user-defined range is substantially less than seven hundred and twenty degrees. 18. The method of controlling an internal combustion engine of claim 17, wherein: the user-defined range is about sixty degrees of crankshaft rotation or less. 19. The method of controlling an internal combustion engine of claim 17, wherein: the user-defined range is about six degrees of crankshaft rotation or less. 20. The method of controlling an internal combustion engine of claim 15, wherein: the angles at which the first set of angle-based cylinder pressure readings are taken are measured by an encoder that is configured to measure the angular position of the crankshaft.