Method for monitoring operational parameters in an internal combustion engine

• US 9,631,568 B2
• Filed: 06/09/2014
• Issued: 04/25/2017
• Est. Priority Date: 06/10/2013
• Status: Active Grant

• Current Assignee: Scania CV AB (Volkswagen AG)
• Original Assignee: Scania CV AB (Volkswagen AG)
• Inventors: Johansson, Bjrn, Pettersson, Magnus
• Primary Examiner(s): Kwon, John
• Assistant Examiner(s): Hoang, Johnny H
• Application Number:
  US14/895,806
• Publication Number:
  US 20160102626A1
• Time in Patent Office: 1,051 Days
• Field of Search: 701102, 701106, 701110-115
• CPC Class Codes: F02B 77/085 with sensors measuring combustion processes, e.g. knocking, pressure, ionization, combustion flame
• CPC Class Codes: F02D 2041/228 Warning displays
• CPC Class Codes: F02D 2200/021 Engine temperature
• CPC Class Codes: F02D 2200/0404 Throttle position
• CPC Class Codes: F02D 2200/0406 Intake manifold pressure
• CPC Class Codes: F02D 2200/0602 Fuel pressure
• CPC Class Codes: F02D 2200/0625 Fuel consumption, e.g. measured in fuel liters per 100 kms or miles per gallon
• CPC Class Codes: F02D 2200/0802 Temperature of the exhaust gas treatment apparatus
• CPC Class Codes: F02D 2200/1002 Output torque
• CPC Class Codes: F02D 41/1448 the characteristics being an exhaust gas pressure
• CPC Class Codes: F02D 41/18 by measuring intake air flow
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: F02D 41/2409 Addressing techniques specially adapted therefor
• CPC Class Codes: F02D 41/2422 Selective use of one or more tables
• CPC Class Codes: F02D 41/2432 Methods of calibration
• CPC Class Codes: F02D 41/248 using a plurality of learned values
• CPC Class Codes: F02D 41/26 using computer, e.g. microprocessor
• CPC Class Codes: G01M 15/05 by combined monitoring of two or more different engine parameters
• CPC Class Codes: Y02T 10/40 Engine management systems

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 T₁. 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.

Claims

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 T₁;

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 T₂ 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 t1 for the respective pairs of sections; and

f) for the respective pairs of sections, testing of the first test variable t1 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 t1 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 t2 for the respective pairs of sections;

h) for the respective pairs of sections, testing the second test variable t2 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 t2 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 t1 and the second test variable t2, 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.