Method and device for determining a signal offset between a crankshaft angle signal and a combustion chamber pressure signal in an internal combustion engine

Patent metadata

Field	Value
Publication number	US-2016258367-A1
Application number	US-201615051349-A
Country	US
Kind code	A1
Filing date	Feb 23, 2016
Priority date	Mar 2, 2015
Publication date	Sep 8, 2016
Grant date	—

Abstract

A method for determining a signal offset between a crankshaft angle signal and a combustion chamber pressure signal in an internal combustion engine, in which an instantaneously measured combustion chamber pressure profile is compared to a calculated, modeled combustion chamber pressure profile. In a method in which the correction values of the signal offset may be ascertained in any operating state of the internal combustion engine, the instantaneously measured combustion chamber pressure profile is shifted with respect to the calculated, modeled combustion chamber pressure profile along a crankshaft angle for generating an artificial signal offset, and a reconstruction quality is determined from this shifted combustion chamber pressure profile in that, from the artificial signal offset along the crankshaft angle of the shifted instantaneously measured combustion chamber pressure profile, a reconstruction error is ascertained as a measure of the effective signal offset between the crankshaft angle signal and the combustion chamber pressure signal.

First claim

What is claimed is:

1 . A method for determining a signal offset between a crankshaft angle signal and a combustion chamber pressure signal in an internal combustion engine, comprising:
comparing an instantaneously measured combustion chamber pressure profile to a calculated, modeled combustion chamber pressure profile; shifting the instantaneously measured combustion chamber pressure profile with respect to the calculated, modeled combustion chamber pressure profile along a crankshaft angle to generate an artificial signal offset; and determining a reconstruction quality from the shifted combustion chamber pressure profile by ascertaining, from the artificial signal offset along the crankshaft angle of the shifted instantaneously measured combustion chamber pressure profile, a reconstruction error as a measure of the signal offset between the crankshaft angle signal and the combustion chamber pressure signal.

2 . The method as recited in claim 1 , wherein at least one reference pressure curve, from which inherent pressures are calculated with the aid of a mathematical model, is measured to determine the modeled combustion chamber pressure curve profile.

3 . The method as recited in claim 1 , wherein the at least one reference pressure curve is measured over a crankshaft angle at different operating points of the internal combustion engine.

4 . The method as recited in claim 1 , wherein the at least one reference pressure curve is measured once during an initialization process.

5 . The method as recited in claim 1 , wherein the instaneous pressures are determined from the at least one reference pressure curve using a principal component analysis (PCA) method.

6 . The method as recited in claim 1 , wherein a signal offset between the crankshaft angle signal and a combustion chamber pressure signal of approximately zero is assumed for the at least one reference pressure curve.

7 . The method as recited in claim 1 , wherein a predefined number of inherent pressures is distributed over a predefined crankshaft angle range during the reconstruction.

8 . The method as recited in claim 1 , wherein the instantaneously measured combustion chamber pressure curve is corrected in the crankshaft angle range with a minimum reconstruction error.

9 . A device for determining a signal offset between a crankshaft angle signal and a combustion chamber pressure signal in an internal combustion engine, comprising:
a combustion chamber pressure sensor and a crankshaft angle sensor to measure an instantaneous combustion chamber pressure profile of the internal combustion engine; a processing unit to compare the instantaneous combustion chamber pressure profile to a calculated combustion chamber pressure profile; an arrangement to shift the instantaneously measured combustion chamber pressure profile with respect to the calculated, modeled combustion chamber pressure profile along a crankshaft angle to generate an artificial signal offset and which reconstructs a pressure curve from the shift; and a unit to determine a reconstruction quality from the artificial signal offset along the crankshaft angle of the shifted instantaneously measured combustion chamber pressure profile, a reconstruction error being ascertained as a measure of the signal offset between the crankshaft angle signal and the combustion chamber pressure signal.

Assignees

• Bosch Gmbh Robert

Inventors

• Rauscher Martin
• Roth Andreas
• Hedinger Raffael
• Fischer Wolfgang
• Gaenzle David
• Onder Christopher H

Classifications

• F02D41/2432

  Methods of calibration · CPC title

• F02D41/008

  Controlling each cylinder individually · CPC title

• F02D35/023

  by determining the cylinder pressure · CPC title

• G01M15/08

  by monitoring pressure in cylinders · CPC title

• F02D35/024 Primary

  using an estimation · CPC title