KR20240027372A - Apparatus and method for measuring the contamination level of a laser scanner using weights - Google Patents

Abstract

A measuring device is provided. The measuring device includes an acquisition unit that acquires a scan result of a laser scanner targeting an object; an extraction unit that extracts a distortion rate of a signal component adjacent to the measurement signal through analysis of the scan result; It may include a measuring unit that measures the degree of contamination of the protective glass located on the laser propagation path using the distortion factor.

Description

Apparatus and method for measuring the contamination level of a laser scanner using weights}

The present invention relates to an apparatus and method for measuring the contamination level of a laser scanner.

A laser scanner can be used to determine location information of an object.

For example, in the pipe production process, a robot automation system can be applied to processes that require pipe end tab cutting and weld bead cutting. These robotic automation systems require accurate relative coordinate information of the target object. At this time, a laser scanner capable of precise measurement with the sensor used may be used.

A laser fired from a laser scanner toward an object can pass through the protective glass that protects the laser scanner. Dust in the workplace, impact from cutting, etc. may cause grooves to form on the protective glass or contamination with foreign substances.

Contamination of the protective glass causes errors in the measurement results of the laser scanner, which can damage robots that move based on the measurement results. Therefore, measuring the degree of contamination on the protective glass of a laser scanner is very important.

In Japanese Patent Laid-Open No. 2002-361452, the surface through which the laser beam passes through the protective glass is observed, the scattered irradiance intensity generated by the laser beam scattering on the particles attached to the protective glass is measured, and this is calculated as the standard scattered irradiance value. A technology for comparing and using the comparison results to determine the degree of contamination of the protective glass is being disclosed.

Japanese Patent Laid-Open No. 2002-361452

The present invention is intended to provide an apparatus and method for measuring the degree of contamination of a laser scanner, specifically, a protective glass, using weights such as distortion.

The measuring device of the present invention includes an acquisition unit that acquires a scan result of a laser scanner targeting an object; an extraction unit that extracts a distortion rate of a signal component adjacent to the measurement signal through analysis of the scan result; It may include a measuring unit that measures the degree of contamination of the protective glass located on the laser propagation path using the distortion factor.

The measurement method of the present invention includes an acquisition step of acquiring scan results of a laser scanner targeting an object; An extraction step of extracting the distortion of signal components adjacent to the measurement signal through analysis of the scan result; It may include a measuring step of measuring the degree of contamination of the protective glass located on the laser propagation path using the distortion factor.

The extraction step may exclude a measurement signal whose signal-to-noise ratio (SNR) is greater than or equal to a first set value.

The extraction step may exclude measurement signals whose z-axis measurement information is 0.

The extraction step may extract the distortion rate of a set number of signal components adjacent to the measurement signal that is not excluded by the signal-to-noise ratio and is not excluded by the z-axis measurement information.

In the measurement step, if the ratio between the distortion information and the measurement signal information is greater than or equal to a second set value, it may be determined to be a measurement error according to the degree of contamination of the protective glass.

According to the measuring device and measuring method of the present invention, the degree of contamination on the protective glass of the laser scanner can be determined using only the measuring operation of the laser scanner that measures the physical characteristics of the object (including the position or distance from the laser scanner). .

In other words, according to the present invention, the contamination level of the protective glass can be measured by using the original measurement operation of the laser scanner without using a separate additional means for measuring the contamination level of the protective glass.

According to the present invention, the cleaning or replacement time for the protective glass of a laser scanner can be easily determined, and the cleaning or replacement time can be communicated to the user using a notification means.

1 is a schematic diagram showing the measuring device of the present invention.
Figure 2 is a schematic diagram showing scan results of a laser scanner.
Figure 3 is a schematic diagram showing different scan results of a laser scanner.
Figure 4 is a schematic diagram showing scan results measured using a measurement jig.
Figure 5 is a flowchart showing the measurement method of the present invention.
6 is a diagram illustrating a computing device according to an embodiment of the present invention.

Below, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts that are not related to the description are omitted, and similar parts are given similar reference numerals throughout the specification.

In this specification, duplicate descriptions of the same components are omitted.

Also, in this specification, when a component is mentioned as being 'connected' or 'connected' to another component, it may be directly connected or connected to the other component, but may be connected to the other component in the middle. It should be understood that may exist. On the other hand, in this specification, when it is mentioned that a component is 'directly connected' or 'directly connected' to another component, it should be understood that there are no other components in between.

Additionally, the terms used in this specification are merely used to describe specific embodiments and are not intended to limit the present invention.

Also, in this specification, singular expressions may include plural expressions, unless the context clearly dictates otherwise.

In addition, in this specification, terms such as 'include' or 'have' are only intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and one or more It should be understood that this does not exclude in advance the presence or addition of other features, numbers, steps, operations, components, parts, or combinations thereof.

Also, in this specification, the term 'and/or' includes a combination of a plurality of listed items or any of the plurality of listed items. In this specification, 'A or B' may include 'A', 'B', or 'both A and B'.

Additionally, in this specification, detailed descriptions of well-known functions and configurations that may obscure the gist of the present invention will be omitted.

Figure 1 is a schematic diagram showing the measuring device 100 of the present invention.

The measurement device 100 shown in FIG. 1 may include an acquisition unit 110, an extraction unit 130, and a measurement unit 150.

The acquisition unit 110 may acquire a scan result of a laser scanner targeting an object.

The extraction unit 130 may extract the distortion rate of a signal component adjacent to the measurement signal through analysis of the scan result obtained by the acquisition unit 110. The extractor 130 may extract a distortion rate within a range in which the signal to noise ratio (SNR) of the measurement signal is less than or equal to a first set value and is not scattered.

The extraction unit 130 may analyze individual result values and adjacent information of the measurement information (profile) of the laser scanner. The extraction unit 130 may extract a weight (distortion rate) according to the difference in information.

If a weight abnormality condition (abnormal condition) is met, the measurement unit 150 can measure the pollution rate according to the number of pollution levels among the entire profile and display the measured pollution rate (pollution level) on the user's terminal. The contamination level displayed to the user can be used as a guide to indicate when to clean, replace, and clean the protective glass.

The measurement unit 150 can measure the degree of contamination of the protective glass located on the laser propagation path using the distortion factor extracted by the extraction unit 130. If the ratio between distortion information and measurement signal information satisfies the second set value, the measuring unit 150 may determine that the protective glass located on the laser propagation path is contaminated.

Distortion may mean total harmonic distortion. In this case, the extraction unit 130 extracts total harmonic distortion (THD), and the measuring unit 150 can predict or measure the degree of contamination of the protective glass using the total harmonic distortion.

Total harmonic distortion is the ratio of the effective value of total harmonics to the effective value of fundamental waves, and can indicate the extent to which harmonic components are included.

Figure 2 is a schematic diagram showing scan results of a laser scanner.

The x-axis information and z-axis information can be output in the form of a profile (640 arrays), and each piece of information can include information on the relative position of the object at the time of measurement.

The response cycle of the laser scanner can be determined according to the user's settings. Both the maximum response speed and the minimum response speed can be equally confirmed through profile information as shown in FIG. 2. The main information is the height information of the x-axis and z-axis during measurement, and a total of 640 pieces of data can be acquired simultaneously. Based on this information, information about the object can be obtained.

Additionally, Figure 2 may show information on an object measured using a laser scanner with uncontaminated protective glass. In other words, Figure 2 may represent data measured in a state where both external noise and the degree of contamination of the protective glass converge to '0'.

Figure 3 is a schematic diagram showing different scan results of a laser scanner.

Figure 3 may show scan results performed while using a laser scanner at a work site for a long period of time. Contamination of the protective glass may occur due to long-term exposure to the work site. Contamination on the protective glass may cause noise in the scan results of the laser scanner (black dots within the red dotted box in FIG. 3).

A method of measuring noise caused by contamination of the protective glass, that is, a method of measuring the degree of contamination, may be as follows.

First, the extraction unit 130 can analyze the signal to noise ratio (SNR) of the measured signal, that is, the scan result obtained through the acquisition unit 110, using Equation 1.

[Formula 1]

Here, Mz(s) represents the intensity of a normal signal carrying information, and Mzn(s) represents the intensity of noise.

During the measurement process, external scattering occurs due to the inherent characteristics of the scanner, and this scattering can serve as an inaccurate data item in pollution measurement. Since the signal detected as SNR abnormality (abnormality) among the measurement signals is due to external scattering, the extractor 130 may exclude the SNR abnormality (abnormality) signal from the pollution measurement items.

The extractor 130 may extract a measurement signal with a low signal-to-noise ratio based on the SNR of Equation 1. As an example, the extractor 130 may exclude a measurement signal whose signal-to-noise ratio is greater than or equal to a first set value. Additionally, the extractor 130 may exclude measurement signals whose z-axis information is '0'. The z-axis information may include depth information, that is, distance information between the object and the laser scanner.

The extractor 130 may extract the distortion of adjacent signal components from a measurement signal that satisfies the signal-to-noise ratio condition and the z-axis information condition and record it in each profile information.

The extractor 130 can calculate the distortion rate of the measurement signal through Equation 2.

[Formula 2]

here, is the measured SNR (see Equation 1), represents the distortion information of 10 signals adjacent to the signal being measured.

Each distortion information can be recorded according to the profile.

The measurement unit 150 measures and calculates the ratio of distortion information and measurement information, and if the ratio is greater than or equal to a second set value, it may be determined that a measurement error according to the degree of pollution exists.

Figure 4 is a schematic diagram showing scan results measured using a measurement jig.

The flat member side of the measuring jig can be scanned by a laser scanner for contamination assessment. By scanning a flat surface, z-axis information can be measured at a constant value. The information measured in this way can be compared by the extractor 130 with z-axis information measured based on each profile distortion information according to Equation 2. The measuring unit 150 may designate a profile area having a value greater than or equal to a set value as a result of comparison as the profile area where contamination occurs.

The measuring unit 150 may perform the final contamination evaluation using the contamination rate of Equation 3.

[Formula 3]

Here, P is the total number of profiles, may be the x-axis resolution of the laser scanner. may represent the number of normal profiles.

Through Equation 3, the measuring unit 150 can predict, evaluate, and measure a pollution level of 0 to 100% according to the x-axis resolution according to the pollution level profile information measured according to the pollution level evaluation method.

The measuring device 100 of the present invention can improve the reliability of pollution level measurement by adding a process using the measuring jig of FIG. 4. Alternatively, the measuring device 100 of the present invention can complete the evaluation of the contamination level without the process of using the measuring jig of FIG. 4. Whether to add a process using the measurement jig of FIG. 4 can be determined based on the measurement precision required at the work site where the laser scanner is applied.

Figure 5 is a flowchart showing the measurement method of the present invention.

The measurement method of FIG. 5 can be performed by the measurement device 100 shown in FIG. 1.

The measurement method may include an acquisition step (S 510), an extraction step (S 520), and a measurement step (S 530).

In the acquisition step (S510), a scan result value of a laser scanner targeting an object may be acquired. The acquisition step (S510) may be performed by the acquisition unit 110.

In the extraction step (S520), the distortion of signal components adjacent to the measurement signal can be extracted through analysis of the scan result. The extraction step (S520) may be performed by the extraction unit 130.

In the measurement step (S530), the degree of contamination of the protective glass located on the laser propagation path can be measured using the distortion factor. The measuring step (S530) may be performed by the measuring unit 150.

In the extraction step (S520), a measurement signal whose signal-to-noise ratio (SNR) is greater than or equal to a first set value may be excluded.

Additionally, the extraction step (S520) may exclude measurement signals in which z-axis measurement information is 0.

In the extraction step (S520), the distortion rate of a set number of signal components adjacent to the measurement signal that is not excluded by the signal-to-noise ratio and not excluded by the z-axis measurement information can be extracted.

In the measurement step (S530), if the ratio between the distortion information and the measurement signal information is greater than or equal to the second set value, it can be determined to be a measurement error due to the degree of contamination of the protective glass.

For example, the information of the measurement signal may be 600 of 640 profiles as normal scan results. Distortion information may be the remaining 40 profiles out of 640 profiles, which are abnormal scan result values such as noise. At this time, the ratio between the two may be 600:40 = 15:1. If the second set value is 20:1, the measurement step (S530) is performed so that the ratio between the information of the measurement signal and the information about the distortion rate is greater than or equal to the second set value (meaning that the number of signal components with a distortion rate is greater than the set ratio). It can be determined that the protective glass is contaminated.

According to the measuring device and measuring method of the present invention, the measuring unit analyzes the z-axis information measured by a laser scanner, and determines the number of values that differ from the normal value by more than the second set value compared to the number of normal values. If it is above this, it can be determined that the protective glass is contaminated.

6 is a diagram illustrating a computing device according to an embodiment of the present invention. The computing device TN100 of FIG. 6 may be a device described herein (e.g., measurement device 100, etc.).

In the embodiment of FIG. 6, the computing device TN100 may include at least one processor TN110, a transceiver device TN120, and a memory TN130. Additionally, the computing device TN100 may further include a storage device TN140, an input interface device TN150, an output interface device TN160, etc. Components included in the computing device TN100 may be connected by a bus TN170 and communicate with each other.

The processor TN110 may execute a program command stored in at least one of the memory TN130 and the storage device TN140. The processor TN110 may refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which methods according to embodiments of the present invention are performed. Processor TN110 may be configured to implement procedures, functions, and methods described in connection with embodiments of the present invention. The processor TN110 may control each component of the computing device TN100.

Each of the memory TN130 and the storage device TN140 can store various information related to the operation of the processor TN110. Each of the memory TN130 and the storage device TN140 may be comprised of at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory TN130 may be comprised of at least one of read only memory (ROM) and random access memory (RAM).

The transceiving device TN120 can transmit or receive wired signals or wireless signals. The transmitting and receiving device (TN120) can be connected to a network and perform communication.

Meanwhile, the embodiments of the present invention are not only implemented through the apparatus and/or method described so far, but may also be implemented through a program that realizes the function corresponding to the configuration of the embodiment of the present invention or a recording medium on which the program is recorded. This implementation can be easily implemented by anyone skilled in the art from the description of the above-described embodiments.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims are also possible. It falls within the scope of invention rights.

100...measuring device 110...acquisition department
130...extraction part 150...measuring part

Claims (4)

An acquisition unit that acquires scan results of a laser scanner targeting an object;
an extraction unit that extracts a distortion rate of a signal component adjacent to the measurement signal through analysis of the scan result;
a measuring unit that measures the degree of contamination of the protective glass located on the laser propagation path using the distortion factor;
A measuring device comprising:
According to paragraph 1,
The extraction unit is a measurement device that extracts the distortion rate within a range in which the signal-to-noise ratio (SNR) of the measurement signal is less than or equal to a first set value and is not scattered.
According to paragraph 1,
The measuring unit determines that the protective glass located on the laser propagation path is contaminated when the ratio between the distortion information and the measurement signal information satisfies a second set value.
In a measuring method performed by a measuring device,
An acquisition step of acquiring scan results of a laser scanner targeting an object;
An extraction step of extracting the distortion of signal components adjacent to the measurement signal through analysis of the scan result;
A measurement step of measuring the degree of contamination of the protective glass located on the laser propagation path using the distortion factor,
The extraction step excludes the measurement signal whose signal-to-noise ratio (SNR) is greater than or equal to the first set value,
The extraction step excludes measurement signals whose z-axis measurement information is 0,
The extraction step extracts a distortion rate of a set number of signal components adjacent to a measurement signal that is not excluded by the signal-to-noise ratio and is not excluded by the z-axis measurement information,
In the measuring step, if the ratio between the distortion information and the measurement signal information is more than a second set value, it is determined as a measurement error according to the degree of contamination of the protective glass.

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