# US 9,435,731 B2 · State determining method, state imparting system, and state determining program

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- Number: US 9,435,731 B2
- Document ID: US9435731B2
- Status: Granted
- Kind: B2
- Application number: 14/920,050
- Filed: 2015-10-22
- Published: 2016-02-11
- Granted: 2016-09-06
- Earliest claimed: 2012-06-22
- Assignees: Nabtesco Corporation
- Applicants: Nabtesco Corporation
- Inventors: Yoshinori Ohnuma; Takuya Shirata; Yasuhito Ida
- Web page: https://patentgrep.com/patent/US9435731B2

## CPC

- G01N 21/251: {Colorimeters; Construction thereof}
- G01N 21/31: Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry {(G01N21/72 takes precedence)}
- G01N 21/59: Transmissivity (G01N21/25 takes precedence)
- G01N 21/8507: {Probe photometers, i.e. with optical measuring part dipped into fluid sample}
- G01N 21/94: Investigating contamination, e.g. dust (G01N21/85 takes precedence)
- G01N 33/2888: {Lubricating oil characteristics, e.g. deterioration (lubricating properties G01N33/30)}
- G01J 2003/466: {Coded colour; Recognition of predetermined colour; Determining proximity to predetermined colour}
- G01N 2021/8514: {with immersed mirror}
- G01N 2201/062: LED's
- G01N 2201/12: Circuits of general importance; Signal processing
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)
- G01J: MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY (light sources F21, H01J, H01K, H05B; investigating properties of materials by optical means G01N)

## Abstract

A state determination method is provided that is capable of determining at least one of the state of degradation of oil in a machine and the state of breakage of the machine with higher accuracy than conventional methods. A state determination method for determining the state of degradation of lubricating oil in a speed reducer and the state of breakage of the speed reducer is characterized by: transmitting white light emitted by a white LED through the lubricating oil, causing an RGB sensor to detect the color of the light transmitted through the lubricating oil by the white LED, and calculating the brightness of the color detected by the RGB sensor (S201); calculating a color component maximum difference that is the difference between a maximum value and a minimum value among the R value, G value, and B value of the color detected by the RGB sensor (S202); and determining the states on the basis of the brightness calculated in S201 and the color component maximum difference calculated in S202 (S203, S207).

## Claims

### Claim 1

A method for detecting a light that has passed through a fluid by an optical sensor, the method comprising:
causing a fluid to enter into a gap of a gap-forming member, the gap located on an optical path from a light-emitting element to a light-receiving element;
causing a light emitted by the light-emitting element to pass through the fluid;
causing the light-receiving element to detect a color of the light that has passed through the fluid;
calculating brightness of the detected color of the light;
calculating a color component calculation value that is a value calculated based on a maximum value and a minimum value among an R value, a G value, and a B value of the detected color of the light; and
determining a state of the fluid based on the calculated brightness and the calculated color component calculation value,
wherein determining a state of the fluid based on the calculated brightness and the calculated color component calculation value comprises determining the deterioration state of the fluid by determining that the state of the fluid is a state predetermined with respect to a combination of the calculated brightness and the calculated color component calculation value.

### Claim 2 (depends on 1)

The method according to claim 1, wherein determining a state of the fluid based on the calculated brightness and the calculated color component calculation value comprises determining the state of the fluid in a machine by determining that the state of the machine is a state predetermined with respect to a combination of the calculated brightness and the calculated color component calculation value.

### Claim 3 (depends on 1)

The method according to claim 1, further comprising adjusting an output of the light-receiving element by: turning the color of the output of the light-receiving element black when an arrival of the light at the light-receiving element is intercepted and turning the color of the output of the light-receiving element white when the fluid is introduced into the machine.

### Claim 4 (depends on 1)

The method according to claim 1, wherein the color component calculation value is a difference between the maximum value and the minimum value, and calculating a color component calculation value comprises calculating a difference between the R value and the B value of the detected color of the light as the color component calculation value.

### Claim 5 (depends on 1)

The method according to claim 1, wherein the state of the fluid is determined without detaching the optical sensor.

### Claim 6

A method for detecting a light that has passed through a fluid by an optical sensor, the method comprising:
causing a fluid to enter into a gap of a gap-forming member, the gap located on an optical path from a light-emitting element to a light-receiving element;
causing a light emitted by the light-emitting element to pass through the fluid; causing the light-receiving element to detect a color of the light that has passed through the fluid;
calculating brightness of the detected color of the light;
calculating a color component calculation value that is a value calculated based on a maximum value and a minimum value among an R value, a G value, and a B value of the detected color of the light; and
determining a state of the fluid based on the calculated brightness and the calculated color component calculation value,
wherein determining a state of the fluid based on the calculated brightness and the calculated color component calculation value comprises determining the state of a machine by determining the breakage state of the machine in accordance with an amount of decrease in the color component calculation value in comparison with that at a point of time when both the calculated brightness and the calculated color component calculation value start to decrease, and the color component calculation value is a difference between the maximum value and the minimum value.

### Claim 7 (depends on 6)

The method according to claim 6, wherein determining the state of the machine comprises, when both the calculated brightness and the calculated color component calculation value decrease, determining time until the machine breaks down as the state of the machine in accordance with time intervals at which the state of the machine is determined and in accordance with an amount of decrease in the color component calculation value at the time intervals.

### Claim 8

A system for notifying at least one of a state of a fluid of a machine and a state of the machine, the system comprising:
an optical sensor permanently mounted on the machine;
a light-emitting element that emits light;
a light-receiving element that detects a color of received light;
a gap-forming member in which a gap into which the fluid enters is located on an optical path from the light-emitting element to the light-receiving element;
a controller configured to:
calculate brightness of the color detected by the light-receiving element;
calculate a color component calculation value that is a value calculated based on a maximum value and a minimum value among an R value, a G value, and a B value of the color detected by the light-receiving element;
determine a state of the fluid based on the calculated brightness and the calculated color component calculation value; and
a display device that notifies the determined state of the fluid,
wherein the controller determines the state of the fluid by determining the deterioration state of the fluid, wherein the deterioration state of the fluid is determined by determining that the state of the fluid is a state predetermined with respect to a combination of the calculated brightness and the calculated color component calculation value.

### Claim 9

A non-transitory computer-readable storage medium with an executable program stored thereon, the program causing a computer to perform:
causing a fluid to enter into a gap of a gap-forming member, the gap located on an optical path from a light-emitting element to a light-receiving element;
calculating brightness of a color of light detected by the light-receiving element at which the light that has been emitted by the light-emitting element and passed through the fluid and arrives;
calculating a color component calculation value that is a value calculated based on a maximum value and a minimum value among an R value, a G value, and a B value of the color detected by the light-receiving element; and
determining at least one of a state of the fluid and a state of a machine based on the calculated brightness and the calculated color component calculation value,
wherein determining a state of the fluid based on the calculated brightness and the calculated color component calculation value comprises determining the deterioration state of the fluid by determining that the state of the fluid is a state predetermined with respect to a combination of the calculated brightness and the calculated color component calculation value.

### Claim 10

A system for notifying at least one of a state of a fluid of a machine and a state of the machine, the system comprising:
an optical sensor permanently mounted on the machine;
a light-emitting element that emits light;
a light-receiving element that detects a color of received light;
a gap-forming member in which a gap into which the fluid enters is located on an optical path from the light-emitting element to the light-receiving element;
a controller configured to:
calculate brightness of the color detected by the light-receiving element;
calculate a color component calculation value that is a value calculated based on a maximum value and a minimum value among an R value, a G value, and a B value of the color detected by the light-receiving element;
determine a state of the fluid based on the calculated brightness and the calculated color component calculation value; and
a display device that notifies the determined state of the fluid,
wherein the controller determines the state of the fluid by determining the state of a machine, wherein the state of the machine is determined by determining the breakage state of the machine in accordance with an amount of decrease in the color component calculation value in comparison with that at a point of time when both the calculated brightness and the calculated color component calculation value start to decrease, and the color component calculation value is a difference between the maximum value and the minimum value.

### Claim 11

A non-transitory computer-readable storage medium with an executable program stored thereon, the program causing a computer to perform:
causing a fluid to enter into a gap of a gap-forming member, the gap located on an optical path from a light-emitting element to a light-receiving element;
calculating brightness of a color of light detected by the light-receiving element at which the light that has been emitted by the light-emitting element and passed through the fluid and arrives;
calculating a color component calculation value that is a value calculated based on a maximum value and a minimum value among an R value, a G value, and a B value of the color detected by the light-receiving element; and
determining at least one of a state of the fluid and a state of a machine based on the calculated brightness and the calculated color component calculation value,
wherein determining a state of the fluid based on the calculated brightness and the calculated color component calculation value comprises determining the state of a machine by determining the breakage state of the machine in accordance with an amount of decrease in the color component calculation value in comparison with that at a point of time when both the calculated brightness and the calculated color component calculation value start to decrease, and the color component calculation value is a difference between the maximum value and the minimum value.