KR101961614B1 - Bearing wear monitoring system and method for bearing wear measuring thereof - Google Patents

Abstract

A method for determining a bearing wear rate of a bearing wear monitoring system according to an embodiment of the present invention is characterized in that a plurality of sensor units mounted on a plurality of cylinders measures a bottom dead center (BDC) level every time the cylinder falls, Calculating a first BDC level which is a moving average based on the BDC level of the BDC; and a logic unit selecting one of the plurality of sensor units and transmitting a BDC level transmission request message to the selected sensor unit via the first line The selected sensor unit transmitting the calculated first BDC level to the logic unit via a second line upon receipt of the BDC level transmission request message; The second BDC level is compensated in accordance with RPM (revolution per minute) to calculate a second BDC level, and based on the calculated second BDC level, And determining a wear degree.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a bearing wear monitoring system,

The present invention relates to a bearing wear monitoring system and a bearing wear determination method thereof, and more particularly, to a bearing wear monitoring system capable of reducing the number of data transmission lines to be installed and the number of necessary input terminals of a logic unit, will be.

Bearing wear monitoring system (BWMS) is a system to determine the wear of major bearings attached to the engine. When the bearing is worn and the thickness changes, the level of the bottom dead center (BDC), which is the maximum falling point of the piston inside the cylinder, is changed. The bearing wear monitoring system determines the wear of the engine bearing based on these changes.

1, a conventional bearing wear monitoring system includes a plurality of sensor units 100-1, 100-2, 100-3, 100-4, and 100- 5, 100-6, ..., 100- (2N-1), 100-2N, and a logic unit 110. Two sensor parts are mounted on the lower part of the cylinder for measuring the BDC level of each cylinder inner piston, and the sensor parts 100-1, 100-2, 100-3, 100-4, 100-5, 100-6, ..., 100- (2N-1), 100-2N measure the BDC level every time the cylinder is lowered and transmit it to the logic unit 110. The logic unit 110 receives the signal from the sensor units 100-1, 100-2, 100-3, 100-4, 100-5, 100-6, ..., 100- (2N-1) Based on the BDC level, the abrasion of the engine bearing is determined according to the abrasion determination algorithm. At this time, each of the sensor units 100-1, 100-2, 100-3, 100-4, 100-5, 100-6, ..., 100- (2N-1) It has its own data transmission line to prevent collision of data.

In this way, the conventional bearing wear monitoring system can not share a data transmission line due to a collision problem. Accordingly, it is necessary to install a data transmission line (number of cylinders x 2), which causes an increase in the cost of line installation have. The logic part also needs to receive input from the number of data transmission lines (number of cylinders x 2), and accordingly, a large number of input terminals are required. In addition, since data is generated every time the cylinder descends (x2 cylinders) and the sensor units transmit data at the same time, a high-performance logic unit is required to process the data.

In order to solve the above problem, there is a demand for a bearing wear monitoring system capable of reducing the number of data transmission lines to be installed and the number of necessary input terminals of the logic unit, and a method for determining bearing wear.

A method for determining a bearing wear rate of a bearing wear monitoring system according to an embodiment of the present invention is characterized in that a plurality of sensor units mounted on a plurality of cylinders measures a bottom dead center (BDC) level every time the cylinder falls, Calculating a first BDC level which is a moving average based on the BDC level of the BDC; and a logic unit selecting one of the plurality of sensor units and transmitting a BDC level transmission request message to the selected sensor unit via the first line The selected sensor unit transmitting the calculated first BDC level to the logic unit via a second line upon receipt of the BDC level transmission request message; The second BDC level is compensated in accordance with RPM (revolution per minute) to calculate a second BDC level, and based on the calculated second BDC level, And determining a wear degree.

A bearing wear monitoring system according to an embodiment of the present invention includes a plurality of sensor units and a logic unit mounted on a plurality of cylinders, wherein the logic unit selects one of the plurality of sensor units, And transmits the BDC level transmission request message to the selected sensor unit through the sensor unit. The selected sensor unit measures the BDC level every time the cylinder falls, calculates a first BDC level, which is a moving average, based on the measured BDC level And transmits the calculated first BDC level to the logic unit via a second line upon receipt of the BDC level transmission request message, and the logic unit compares the first BDC level from the selected sensor unit with the RPM The second BDC level is calculated and the wear degree is determined based on the calculated second BDC level according to the wear degree determination algorithm.

A bearing wear monitoring system capable of reducing the number of data transmission lines to be installed and the number of necessary input terminals of the logic unit and a method of determining the bearing wear rate thereof can be provided.

1 is a block diagram showing the configuration of a conventional bearing wear monitoring system,
2 is a block diagram showing the configuration of a bearing wear monitoring system according to an embodiment of the present invention;
3 is a block diagram illustrating a BDC level measurement and transmission method of a sensor unit in a bearing wear monitoring system according to an embodiment of the present invention;
FIG. 4 is a block diagram illustrating a BDC level reception and a bearing wear detection method of a logic unit in a bearing wear monitoring system according to an embodiment of the present invention.

It is noted that the technical terms used herein are used only to describe specific embodiments and are not intended to limit the invention. It is also to be understood that the technical terms used herein are to be interpreted in a sense generally understood by a person skilled in the art to which the present invention belongs, Should not be construed to mean, or be interpreted in an excessively reduced sense. Further, when a technical term used herein is an erroneous technical term that does not accurately express the spirit of the present invention, it should be understood that technical terms that can be understood by a person skilled in the art are replaced. In addition, the general terms used in the present invention should be interpreted according to a predefined or prior context, and should not be construed as being excessively reduced.

Also, the singular forms "as used herein include plural referents unless the context clearly dictates otherwise. In the present application, the term " comprises, " " comprising, " or " comprising ", etc. should not be construed as necessarily including the various components or steps described in the specification, Or some steps may not be included, or may be interpreted to include additional components or steps.

Also, suffixes "module", "unit" and "part" for the components used in the present specification are given or mixed in consideration of ease of specification, and each component having its own distinct meaning or role no.

Furthermore, terms including ordinals such as first, second, etc. used in this specification can be used to describe various elements, but the elements should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals refer to like or similar elements throughout the several views, and redundant description thereof will be omitted.

In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. It is to be noted that the accompanying drawings are only for the purpose of facilitating understanding of the present invention, and should not be construed as limiting the scope of the present invention with reference to the accompanying drawings.

The present invention relates to a bearing wear monitoring system and a bearing wear determination method thereof. More particularly, the present invention relates to a bearing wear monitoring system capable of reducing the number of data transmission lines to be installed and the number of necessary input terminals of a logic unit, And a method for determining wear of a bearing.

2 is a block diagram showing the configuration of a bearing wear monitoring system according to an embodiment of the present invention.

The bearing wear monitoring system according to an embodiment of the present invention includes a plurality of sensor units 200-1, 200-2, 200-3, 200-4, 200-5, 200-6, ..., 200-2 (2N-1), 200-2N), and a logic unit 210. [

Referring to FIG. 2, in order to measure the BDC level of each cylinder inner piston, two sensor units are mounted on the lower part of each cylinder in the engine. A plurality of sensor units 200-1, 200-2, 200-3, 200-4, 200-5, 200-6, ..., 200- (2N- 1, and 200-2N measure the BDC level every time the cylinder is lowered, store the measured BDC level, and when transmission is requested by the logic unit 210, transmits the RPM (revolution per minute) do. At this time, the logic unit 210 is a part of the sensor units 200-1, 200-2, 200-3, 200-4, 200-5, 200-6, ..., 200- (2N-1) The selected sensor unit requests transmission of the BDC level, and the selected sensor unit transmits the BDC level to the logic unit 210. Since the sensor unit needs to transmit two or more cumulative measured values (i.e., BDC level) when the transmission request by the logic unit 210 is late, the sensor unit also transmits the cumulative measurement value and the accumulated number of measurement values together . Each of the sensor units 200-1, 200-2, 200-3, 200-4, 200-5, 200-6, ..., 200- (2N-1), 200-2N transmits a BDC level It is not necessary to have a unique data transmission line in order to prevent data collision.

Accordingly, the bearing wear monitoring system according to an embodiment of the present invention may include two data transmission lines, that is, a plurality of sensor units 200-1 and 200-2 in the logic unit 210, as shown in FIG. , 200-3, 200-4, 200-5, 200-6, ..., 200- (2N-1), and 200-2N, a first line 202 for transmitting a transmission request to one sensor unit, Only the second line 204 for transmitting the BDC level, the RPM, and the accumulated number of the measured values to the sensor unit logic unit 210 receiving the transmission request is required. This can reduce the number of data transmission lines and the number of input terminals required for the logic section to be installed, and can also provide sequential data processing, which provides flexibility in the performance of the logic section.

The logic unit 210 receives a signal from the sensor units 200-1, 200-2, 200-3, 200-4, 200-5, 200-6, ..., 200- (2N-1) Based on the received BDC level, the wear state of the engine bearing is determined according to the wear determination algorithm. Here, the BDC level varies depending on the RPM of the engine, in addition to the engine bearing wear. Therefore, it is necessary to remove the BDC level which varies according to the RPM in order to determine the exact wear rate. The logic unit 210 receives the data from the sensor units 200-1, 200-2, 200-3, 200-4, 200-5, 200-6, ..., 200- (2N-1) When the level is received, it is first performed from the compensation according to the RPM.

There are two types of wear determination algorithms, a rapid wear algorithm and a slow wear algorithm. The fast wear algorithm is an algorithm that analyzes the BDC level, which is suddenly changed by external factors such as temperature and shock. It generates an alarm when something goes wrong. The slow wear algorithm is an algorithm that analyzes the BDC level, which gradually changes with time. If there is a problem, it generates pre-warning, slow down, and alarm according to the condition.

The BDC level may generate instantaneous noise due to measurement error and vibration. We use moving averages to eliminate these noises. Since the slow wear algorithm assumes a slow change, it applies a smaller weight to the new BDC level and assumes a fast change in the fast wear algorithm, thus applying more weight to the new BDC level than the slow wear algorithm.

Here, a plurality of sensor units 200-1, 200-2, 200-3, 200-4, 200-5, 200-6, ..., 200- (2N -1) and 200-2N, and the operation of the logic unit 210 will be described below.

First, the logic unit 210 includes a plurality of sensor units 200-1, 200-2, 200-3, 200-4, 200-5, 200-6, ..., 200- (2N-1) -2N), and transmits a bottom dead center (BDC) level request message to the selected sensor unit via the first line 202.

The selected sensor unit measures a BDC level every time the corresponding cylinder is lowered, calculates a moving average (S _{rapidfast *} ) of the BDC level based on the measured BDC level, and, upon receipt of the BDC level transmission request message , And transmits the calculated moving average of the BDC level to the logic unit 210 via the second line 204. [ Here, the selected sensor unit updates the moving average of the BDC level so that the measured BDC level is accumulated every time the cylinder is lowered until the BDC level transmission request message is received from the logic unit 210, Upon receiving the transmission request message, the moving average of the updated BDC level, the RPM, and the accumulated number of measured values are transmitted to the logic unit 210 through the second line 204.

The logic unit 210 calculates a compensation value (S _rapidfast ) of the BDC level by compensating a moving average of the BDC level from the selected sensor unit according to RPM (revolution per minute) And determines the degree of abrasion according to the wear degree determination algorithm based on the value. Here, the logic unit 210 determines an S _reference which is a BDC level varying according to the RPM, removes S _reference by an accumulated number of measurement values at the moving average of the BDC level, and calculates a moving average of the BDC level The compensation value of the BDC level (S _rapidfast ) is calculated. The logic unit 210 calculates an error value between the measured BDC level and the S _reference on the basis of the calculated compensation value of the BDC level, and based on the calculated error value, Judge wear.

3 is a block diagram illustrating a BDC level measurement and transmission method of a sensor unit in a bearing wear monitoring system according to an embodiment of the present invention.

Referring to FIG. 3, the sensor unit in the bearing wear monitoring system measures the BDC level every time the corresponding cylinder descends in step 301, and calculates a moving average (S _{rapidfast *} ) of the BDC level based on the measured BDC level And updates the moving average of the BDC level so that the measured BDC level is accumulated every time the cylinder is lowered until the BDC level transmission request message is received from the logic unit.

Here, the moving average of the BDC level (S _{rapidfast *} ) can be calculated as shown in Equation (1) below.

Here, S _{old _ rapidfast *} denotes a moving average calculated by accumulating the BDC levels measured up to the immediately preceding cylinder drop-off time, S _new denotes a BDC level measured at the current cylinder-falling time, X ₁ denotes a moving average As a weight for S _new , it may be predetermined, for example, to be 0.2. For reference, the moving average means an average value obtained by performing a calculation with a larger weight on some data.

In step 303, the sensor unit checks whether a BDC level transmission request message requesting transmission of the BDC level is received from the logic unit via the first line.

If the BDC level transmission request message is not received in step 303, the sensor unit returns to step 301 and repeats the following steps.

On the other hand, if the BDC level transmission request message is received in step 303, the sensor unit transmits the moving average of the BDC level stored in the memory and the cumulative number of RPMs and measurement values to the logic unit via the second line And initializes the accumulated number of the measured values, and then returns to step 301 to repeat the following steps.

FIG. 4 is a block diagram illustrating a BDC level reception and a bearing wear detection method of a logic unit in a bearing wear monitoring system according to an embodiment of the present invention.

Referring to FIG. 4, in step 401, the logic unit in the bearing wear monitoring system selects one of the plurality of sensor units mounted on the plurality of cylinders in the engine.

In step 403, the logic unit generates a BDC level transmission request message requesting transmission of a BDC level, and transmits the generated BDC level transmission request message to the selected sensor unit via a first line.

In step 405, the logic unit checks whether the BDC level moving average (S _{rapidfast *} ) and the accumulated number of RPMs and measurement values are received from the selected sensor unit through the second line.

If the moving average of the BDC level and the cumulative number of RPMs and measurement values are received from the selected sensor unit through the second line in step 405, the logic unit obtains the S _reference , which is a BDC level varying according to the RPM, And calculates a compensation value (S _rapidfast ) of the BDC level by compensating the moving average of the BDC level by removing S _reference by the accumulated number of measured values at the moving average of the BDC level.

Here, the compensation value (S _rapidfast ) of the BDC level can be calculated as Equation (2) below.

Where S _reference is the BDC level that varies with RPM and is determined by the value learned by the logic unit and k represents the cumulative number of measurements.

In step 409, the logic unit calculates an error value (S _compensate ) of the BDC level based on the calculated compensation value of the BDC level (S _rapidfast ).

First, the error value S _compensate , which is the error of the newly measured value, is determined by subtracting the value S _reference learned by the logic unit from the value newly measured by the sensor unit (i.e., the BDC level) S _new , And S _rapidfast can be determined by taking a moving average at a high weighting value of X ₁ (for example, 0.2) in the determined error value S _compensate as shown in Equation (3) below.

Here, S _{old _ rapidfast} represents the previously calculated S _rapidfast .

Since the logic part in the bearing wear monitoring system according to the embodiment of the present invention has already calculated and known the S _rapidfast as in Equation (2), the following logic equation can be obtained by using Equation (3) , The error value (S _compensate ) of the BDC level can be calculated.

Then, in step 411, the logic unit calculates a BDC level change value S _rapidwear and a BDC level change value applicable to the fast wear algorithm and the slow wear algorithm, respectively, using a moving average based on the calculated error value (S _compensate ) S _slowwear ).

Here, the BDC level change values (S _rapidwear and S _slowwear ) applicable to the quick wear algorithm and the slow wear algorithm can be calculated as shown in Equation (5) below.

Here, X ₂ can be predetermined as a weight for the S _compensate at the moving average, for example, 0.0001, and X ₃ can be predetermined as a weight for the S _compensate at the moving average, for example, 0.05. The change value (S _rapidwear ) of the BDC level that can be applied to the quick wear algorithm is a value indicating a change in the BDC level which is abruptly changed due to external factors such as temperature and impact, that is, (S _rapidfast ) of the BDC level corresponding to a value indicating a large change greater than or equal to the reference value minus S _rapidslow corresponding to a value indicating a small change below the reference value. Here, the S _rapidslow is determined as a value obtained by taking a moving average at a low weighting value of X ₂ (for example, 0.0001) in the calculated error value S _compensate of the BDC level. The S _rapidfast uses a high weighting of X ₁ (for example, 0.2) at the moving average, as already mentioned. The change value (S _slowwear) of BDC level that can be applied to slow the wear algorithm, the X ₃ as a value representing a gradual change in the varying BDC level with time, the calculated error values for the BDC level (S _compensate) ( 0.0 > 0.05, < / RTI > for example). Since the slow wear algorithm assumes that the BDC level changes slowly, a small weight (for example, X ₃ = 0.05) is applied to the error value (S _compensate ) of the new BDC level measured within a short period of time in the moving average , The change value (S _slowwear ) of the BDC level applicable to the slow wear algorithm is maintained to be an existing value than the new value. In addition, since the BDC level is assumed to change rapidly in the case of the quick wear algorithm, a larger proportion of the error value (i.e., S _compensate ) of the new BDC level measured within a short period of time than the slow wear algorithm For example, X ₁ = 0.2) is applied.

Then, in step 413, the logic unit determines a wear determination algorithm, that is, a fast wear algorithm and a slow wear, based on the BDC level change values (S _rapidwear and S _slowwear ) applicable to the calculated quick wear algorithm and the slow wear algorithm, respectively According to the algorithm, the wear of the bearing of the corresponding cylinder inner piston is judged.

In step 415, the logic unit checks whether selection of all the sensor units mounted on the plurality of cylinders in the engine is completed.

If it is determined in step 415 that the selection of all of the sensor units mounted on the plurality of cylinders in the engine is not completed, the logic unit selects one of the plurality of sensor units mounted on the plurality of cylinders in the engine, After selecting the sensor unit, the process returns to step 403 and repeats the following steps.

On the other hand, if the selection of all the sensor units mounted on the cylinders in the engine is completed in step 415, the logic unit terminates the algorithm according to the present invention.

As described above, the bearing wear monitoring system and the bearing wear determination method according to the embodiments of the present invention can reduce the number of data transmission lines to be installed and the number of necessary input terminals of the logic unit, This has the advantage of being flexible in logic performance.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, Those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Therefore, the spirit of the present invention should not be construed as being limited to the above-described embodiments, and all of the equivalents or equivalents of the claims, as well as the following claims, I will say.

100-1, 100-2, 100-3, 100-4, 100-5, 100-6, ... , 100 - (2N-1), 100-2N:
110:
200-1, 200-2, 200-3, 200-4, 200-5, 200-6, ... , 200- (2N-1), and 200-2N:
210:

Claims (10)

Each of a plurality of sensor units mounted on a plurality of cylinders measures a bottom dead center (BDC) level every time the cylinder falls, and calculates a first BDC level that is a moving average based on the measured BDC level and,
The logic unit selecting one of the plurality of sensor units and transmitting a BDC level transmission request message to the selected sensor unit via the first line,
Transmitting the calculated first BDC level to the logic unit through a second line different from the first line upon receipt of the BDC level transmission request message;
The logic unit calculates a second BDC level by compensating a first BDC level from the selected sensor unit according to RPM (revolution per minute), and calculates a wear degree based on the calculated second BDC level A method for determining bearing wear of a bearing wear monitoring system including a determining process.
The method according to claim 1,
And updating the first BDC level so that the measured BDC levels are accumulated every time the cylinder is lowered until the BDC level transmission request message is received from the logic unit,
Here, the step of transmitting the first BDC level may include transmitting the updated first BDC level, the RPM, and the cumulative number of measured values to the selected sensor unit through the second line according to the reception of the BDC level transmission request message And transmitting the calculated bearing wear to the logic unit.
The method according to claim 1,
Wherein the level of S 1 BDC _{rapidfast *} is, to <Equation> and as bearing wear determination method of bearing wear monitoring system characterized in that the calculation.

Here, S _{old_rapidfast *} denotes a moving average value calculated by accumulating the BDC levels measured up to the immediately preceding cylinder falling-off time, S _new denotes a BDC level measured at the current cylinder falling point, and X ₁ denotes a moving average S _new Weighted.
4. The method of claim 3, wherein the calculating the second BDC level comprises:
Determining an S _reference which is a BDC level that varies according to the RPM;
And calculating a second BDC level by compensating the first BDC level by removing S _reference by an accumulated number of measurement values at the first BDC level,
Here, the second BDC level S _rapidfast is calculated as follows: < EMI ID = _2.0 >

Where S _reference is the BDC level that varies with RPM and k is the cumulative number of measured values.
5. The method according to claim 4,
Calculating a third BDC level which is an error value between the measured BDC level and the S _reference based on the calculated second BDC level;
And determining a wear degree based on the calculated third BDC level according to the wear degree determination algorithm,
The method of claim 1, wherein the third BDC level S _compensate is calculated as: < EMI ID = 15.0 >

Where S _{old _ rapidfast} represents the second BDC level calculated immediately before.
A plurality of sensor units mounted on a plurality of cylinders,
Logic portion,
The logic unit selects one of the plurality of sensor units, transmits a bottom dead center (BDC) level request message to the selected sensor unit via the first line,
The selected sensor unit measures a BDC level every time the corresponding cylinder equipped with the selected sensor unit is lowered, calculates a first BDC level which is a moving average based on the measured BDC level, Transmits the calculated first BDC level to the logic unit via a second line different from the first line,
The logic unit calculates a second BDC level by compensating a first BDC level from the selected sensor unit according to RPM (revolution per minute), and calculates a wear degree based on the calculated second BDC level Wherein the bearing wear monitoring system comprises:
The method according to claim 6,
The selected sensor unit updates the first BDC level so that the measured BDC level is accumulated every time the cylinder is lowered until the BDC level transmission request message is received from the logic unit, And transmits the updated first BDC level, RPM, and accumulated number of measured values to the logic unit via a second line.
The method according to claim 6,
Wherein the level of S 1 BDC _{rapidfast *} is, to <Equation> and as bearing wear monitoring system characterized in that the calculation.

Here, S _{old_rapidfast *} denotes a moving average value calculated by accumulating the BDC levels measured up to the immediately preceding cylinder falling-off time, S _new denotes a BDC level measured at the current cylinder falling point, and X ₁ denotes a moving average S _new Weighted.
9. The semiconductor memory device according to claim 8,
Calculating a second BDC level by determining an S _reference that is a BDC level that varies according to the RPM, compensating the first BDC level by removing S _reference by an accumulated number of measured values at the first BDC level,
Here, the second BDC level S _rapidfast is calculated as follows: < EMI ID = _1.0 >

Where S _reference is the BDC level that varies with RPM and k is the cumulative number of measured values.
10. The apparatus of claim 9,
Calculating a third BDC level, which is an error value between the measured BDC level and the S _reference , based on the calculated second BDC level, and based on the calculated third BDC level, However,
Here, the third BDC level S _compensate is calculated as follows: < EMI ID = 2.0 >

Where S _{old _ rapidfast} represents the second BDC level calculated immediately before.

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