Method for monitoring operational parameters in an internal combustion engine

Patent metadata

Field	Value
Publication number	US-9631568-B2
Application number	US-201414895806-A
Country	US
Kind code	B2
Filing date	Jun 9, 2014
Priority date	Jun 10, 2013
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

A method to monitor an operating characteristic in a combustion engine: creating a monitoring matrix divided into a number of sections for storage of information, wherein each section is associated with specific intervals of engine speed ω and torque requested from the engine T 1 . When the engine is used during an operational time window with a pre-determined duration, measuring or estimating an operating characteristic and associating the characteristic with the monitoring matrix's respective section, associated with the current engine speed and the torque requested. For each section in the monitoring matrix, calculating at least one statistical parameter describing the operating characteristic associated with this section during the current operational time window; storing the statistical parameter(s) in the respective section. At the end of the operational time window, storing information in the monitoring matrix in an individual storage matrix associated with the operational time window, wherein the monitoring matrix is emptied of information.

First claim

The invention claimed is:

1. A method to monitor and store information about an operating characteristic in a combustion engine, comprising the steps:
a) creating a monitoring matrix divided into several sections for storage of information on a data storage medium, wherein each section is associated with specific intervals of values for reference engine characteristics of the combustion engine, wherein the reference engine characteristics comprise engine speed ω and torque requested from the engine T 1 ;
b) using the engine during an operational time window of a predetermined duration, detecting the reference engine characteristics during the time window, and estimating or measuring an operating characteristic on several occasions, and associating each estimated or measured value for the operating characteristic with the monitoring matrix's respective section, associated with values of the reference engine characteristics at the respective occasions;
c) for each section in the monitoring matrix, calculating at least one statistical parameter describing the estimated or measured values of the operating characteristic associated with this section during the current operational time window, and storing the at least one calculated statistical parameter in the respective section; and
d) at the end of the operational time window, storing information, which had been stored in the monitoring matrix, in an individual storage matrix associated with the operational time window, and emptying the monitoring matrix of information.

2. A method according to claim 1 , further comprising selecting the estimated or measured operating characteristic from among the combustion engine's charge pressure, exhaust back pressure, air mass flow, fuel pressure, fuel consumption, engine temperature, catalyst temperature, auxiliaries connection degree, turbine speed, throttle position, or by the torque generated by the combustion engine.

3. A method according to claim 1 , further comprising carrying out step b) through estimating or measuring of a first operating characteristic, wherein the first operating characteristic is selected so that a relevant second operating characteristic for the respective section may be described as a function of the estimated or measured first operating characteristic and one of the section's reference engine characteristics.

4. A method according to claim 3 , further comprising selecting the first operating characteristic so that the torque T 2 generated by the combustion engine may be described for the respective section as a function of the estimated or measured first operating characteristic and of the section's reference characteristic of engine's engine speed ω.

5. A method according to claim 1 , further comprising repeating steps b)-d) for at least one operational time window following after a relevant operational time window.

6. A method according to claim 5 , further comprising the following steps:
e) comparing information stored in a first comparison matrix, which is comprised of one of the storage matrices or the monitoring matrix, with information stored in a first reference matrix with a corresponding division into sections, forming a first test variable t 1 for the respective pairs of sections; and
f) for the respective pairs of sections, testing of the first test variable t 1 against a storage criterion, wherein the information stored in the first comparison matrix is saved only if the storage criterion is met.

7. A method according to claim 6 , further comprising forming the first test variable t 1 for the respective pairs of sections by calculating the difference between a statistical parameter stored in the first comparison matrix and a value stored in the first reference matrix.

8. A method according to claim 6 , further comprising the following steps:
g) comparing information stored in a second comparison matrix, wherein the second comparison matrix comprises one of the storage matrices or the monitoring matrix, with information stored in a second reference matrix with a corresponding division into sections, and forming a second test variable t 2 for the respective pairs of sections;
h) for the respective pairs of sections, testing the second test variable t 2 against an alarm criterion and, if that the alarm criterion is met,
i) generating an error code.

9. A method according to claim 8 , further comprising for the respective pairs of sections, forming the second test variable t 2 by calculating the difference between a statistical parameter stored in the second comparison matrix and a value stored in the second reference matrix.

10. A method according to claim 8 , further comprising determining that the storage criterion and/or the alarm criterion is met if the first test variable t 1 and the second test variable t 2 , respectively, for at least one of the pairs of sections, exceeds a predetermined threshold value for the respective pair.

11. A method according to claim 6 , further comprising one of the storage matrices associated with a previous operational time window is used as at least one of the reference matrices.

12. A method according to claim 11 , further comprising using the storage matrix, in which data from an operational time window has been stored the longest, as at least one of the reference matrices.

13. A method according to claim 6 , further comprising using the storage matrix associated with the most recent operational time window as at least one of the comparison matrices.

14. A method according to claim 1 , further comprising in step d), storing information about the operational time window during which the at least one statistical parameter has been calculated together with the information from the monitoring matrix.

15. A method according to claim 1 , further comprising calculating at least two of the statistical parameters for each section.

16. A method according to claim 13 , wherein the statistical parameters comprise mean and/or median and/or variance and/or standard deviation.

17. A method according to claim 1 , further comprising calculating at least one statistical parameter recursively during the operational time window.

18. A computer program product comprising a non-volatile data storage medium which is readable by a computer, a computer program comprising computer code stored on the medium; the computer program code is operable to cause a computer to implement a method according to claim 1 , when the computer code is executed in the computer.

19. An electronic control device comprising an execution means, a memory connected to the execution means and a data storage medium connected to the execution means; the computer program code in a computer program according to claim 18 is stored on the data storage medium.

20. A motor vehicle comprising an electronic control device according to claim 19 .

Assignees

• Scania Cv Ab

Inventors

• Johansson Björn
• Pettersson Magnus

Classifications

• F02D2200/0404

  Throttle position · CPC title

• B60R16/0232

  for measuring vehicle parameters and indicating critical, abnormal or dangerous conditions · CPC title

• F02D2200/0406

  Intake manifold pressure · CPC title

• F02D2200/1004

  Estimation of the output torque · CPC title

• F02D2200/1002

  Output torque · CPC title