Condition based oil management
Method for monitoring a lubricant of a combustion engine, wherein measured numerical values are acquired with at least one sensor over a running time of a combustion engine, wherein the measured numerical values are representative of an oil quality of an engine oil of the combustion engine, wherein an oil sampling interval is adapted depending on at least one measured numerical value and/or a variable derived therefrom.
1 . A method for monitoring a lubricant of a combustion engine, comprising:
acquiring a plurality of measured numerical values at a measurement frequency in a range between 0.5 Hz and 3 Hz with at least one sensor at the combustion engine over a running time of the combustion engine, wherein the measured numerical values are representative of an oil quality of an engine oil of the combustion engine; and
adapting an oil sampling interval for analysis of the engine oil away from the combustion engine in a laboratory depending on at least one measured numerical value of the plurality of measured numerical values and/or a variable derived therefrom, wherein adapting the oil sampling interval comprises:
shortening the oil sampling interval when the at least one measured numerical value or the variable derived therefrom indicates the oil quality is less than expected; and
lengthening the oil sampling interval when the at least one measured numerical value or the variable derived therefrom indicates the oil quality is greater than expected.
2 . The method of claim 1 , comprising deriving an absolute value of the oil quality from the at least one measured numerical value, wherein the absolute value is used for adapting the oil sampling interval.
3 . The method of claim 1 , wherein acquiring the plurality of measured numerical values comprises continuously acquiring the plurality of measured numerical values during the running time of the combustion engine at the measurement frequency, wherein the method further comprises continuously determining the oil quality of the engine oil in response to the plurality of measured numerical values during the running time of the combustion engine, and continuously outputting updates to the oil sampling interval in response to any shortening and lengthening of the oil sampling interval.
4 . The method of claim 1 , comprising determining a rate of change of at least two successive measured numerical values of the plurality of measured numerical values, wherein adapting the oil sampling interval comprises changing the oil sampling interval in response to the rate of change.
5 . The method of claim 4 , wherein adapting the oil sampling interval comprises changing the oil sampling interval in response to the rate of change reaching a limit value.
6 . The method of claim 1 , wherein the plurality of measured numerical values comprises an iron content, an oxidation rate, a water content, an i-pH value, or a combination thereof.
7 . The method of claim 1 , comprising determining at least two measured numerical values of the plurality of measured numerical values and/or variables derived therefrom by the at least one sensor at prespecified points in time at time intervals prespecified relative to each other and/or in defined operating conditions of the combustion engine.
8 . The method of claim 1 , further comprising:
initiating an oil sample of the engine oil for the analysis of the engine oil away from the combustion engine in the laboratory in response to the oil sampling interval; and
obtaining results from the analysis in the laboratory, wherein the results include laboratory values of the oil quality and a decision to change the engine oil at a first time or at a second time after further operation of the combustion engine.
9 . The method of claim 1 , wherein an electrochemical state variable, comprising electrical conductivity and/or permittivity, of the engine oil is measured by the at least one sensor, wherein the electrochemical state variable represents the at least one measured numerical value of the oil quality of the engine oil.
10 . The method of claim 1 , comprising:
comparing the plurality of measured numerical values and/or the variables derived therefrom with a condition, and
adapting the oil sampling interval in response to the plurality of measured numerical values not corresponding to the condition.
11 . The method of claim 10 , comprising determining the condition comprising an ageing rate for the engine oil under normal conditions and/or in tests in dependence on operating hours of the combustion engine.
12 . The method of claim 1 , comprising outputting the oil sampling interval as a notification, and outputting a change in the oil sampling interval as a warning.
13 . A combustion engine, comprising:
at least one oil circuit configured to transport the engine oil for lubricating and/or cooling the combustion engine;
the at least one sensor; and
a controller configured to receive the at least one measured numerical value, wherein the controller is configured to monitor the oil quality of the engine oil and adapt the oil sampling interval depending on the at least one measured numerical value of the plurality of measured numerical values and/or the variable derived therefrom according to the method of claim 1 .
14 . A tangible, computer-readable medium storing instructions executable to perform the method according to claim 1 .
15 . A system, comprising:
a controller configured to:
acquire a plurality of measured numerical values at a measurement frequency in a range between 0.5 Hz and 3 Hz with at least one sensor at a combustion engine over a running time of the combustion engine, wherein the measured numerical values are representative of an oil quality of an engine oil of the combustion engine; and
adapt an oil sampling interval for analysis of the engine oil away from the combustion engine in a laboratory depending on at least one measured numerical value of the plurality of measured numerical values and/or a variable derived therefrom, wherein the controller is configured to adapt the oil sampling interval by:
shortening the oil sampling interval when the at least one measured numerical value or the variable derived therefrom indicates the oil quality is less than expected; and
lengthening the oil sampling interval when the at least one measured numerical value or the variable derived therefrom indicates the oil quality is greater than expected.
16 . The system of claim 15 , comprising an oil circuit configured to circulate the engine oil, wherein the oil circuit comprises the at least one sensor separate from the combustion engine.
17 . The system of claim 16 , wherein the oil circuit comprises an oil cooler and an oil filter, the at least one sensor is disposed at a position between the oil cooler and the oil filter, the plurality of measured numerical values are influenced by the temperature due to the position of the at least one sensor downstream of the oil cooler, the oil cooler is configured to control the temperature of the engine oil monitored by the at least one sensor, and the plurality of measured numerical values are not influenced by filtering due to the position of the at least one sensor upstream of the oil filter.
18 . The system of claim 15 , comprising the combustion engine having the controller.
19 . A system, comprising:
a combustion engine having an oil circuit and at least one sensor along the oil circuit;
a controller configured to:
monitor the at least one sensor to obtain sensor feedback at a measurement frequency in a range between 0.5 Hz and 3 Hz, wherein the sensor feedback or a variable derived therefrom indicates an oil quality of an engine oil of the combustion engine; and
adapt an oil sampling interval for analysis of the engine oil away from the combustion engine in a laboratory based on the sensor feedback or the variable derived therefrom, wherein the controller is configured to adapt the oil sampling interval by:
shortening the oil sampling interval when the sensor feedback or the variable derived therefrom indicates the oil quality is less than expected; and
lengthening the oil sampling interval when the sensor feedback or the variable derived therefrom indicates the oil quality is greater than expected.
20 . The system of claim 19 , wherein the controller is configured to adapt the oil sampling interval at least by changing the oil sampling interval based on a comparison between a condition and the sensor feedback or the variable derived therefrom, wherein the condition is representative of an expected oil quality or an expected ageing rate for the engine oil under normal conditions and/or in tests in dependence on operating hours of the combustion engine.
21 . The system of claim 19 , wherein the controller is configured to adapt the oil sampling interval based on a rate of change of the sensor feedback or the variable derived therefrom.
22 . The system of claim 21 , wherein the sensor feedback or the variable derived therefrom comprises an iron content, an oxidation rate, a water content, an i-pH value, or a combination thereof.
23 . The system of claim 19 , wherein the controller is configured to;
perform a plausibility check to classify the sensor feedback or variables derived therefrom as plausible or non-plausible based on plausibility limits;
adapt the oil sampling interval in response to the plausibility check classifying the sensor feedback or variables derived therefrom as plausible; and
not adapt the oil sampling interval in response to the plausibility check classifying the sensor feedback or variables derived therefrom as non-plausible.