Combustion control in an internal combustion engine
AssigneeDelphi Technologies, Inc.
InventorsJames F. Sinnamon, Mark C. Sellnau
Life of this patent
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Abstract
The present invention relates to: self-tuning engine control algorithms using inputs from transducers that measure pressure in the engine cylinders, and from an engine crankshaft rotational position sensor; methods of processing the input signals to “self-tune” or learn accurate values for a) pressure transducer voltage offset, b) crank position encoder error and c) engine compression ratio; improved pressure-ratio-based algorithms for calculating cylinder heat release fraction as a function of crank angle.
Claims9
A method of finding a voltage offset of a transducer used to measure pressure within an engine cylinder, the transducer being arranged to output a voltage signal Et(θ) and having a voltage signal offset value Ebias at zero cylinder pressure and the contents of the engine cylinder undergoing a polytropic process, the method comprising:
- a) calculating the ratio of specific heats for the cylinder contents;
- b) measuring at least two voltage signal outputs from the transducer;
- c) calculating the volume of the cylinder at the points the voltage signals are measured;
- d) using the values from (a), (b) and (c) to derive a value for the voltage signal offset Ebias.
A device for finding a voltage offset of a transducer used to measure pressure within an engine cylinder, the transducer being arranged to oulput a voltage signal Et(θ) and basting a voltage signal offset value Ebias at zero cylinder pressure and the contents of the engine cylinder undergoing a polytropic process, the device comprising:
- input means for receiving at least two measured voltage signal outputs from the transducer;
- processing means arranged to calculate the ratio of specific heats for the cylinder contents;
- calculate the volume of the cylinder at the point the voltage signals are measured and to subsequently derive a value for the voltage signal offset Ebias.
Dependencies are inferred from the claim text.