CN117589061A - Workpiece position detection system - Google Patents

Abstract

The invention discloses a workpiece position detection system in the technical field of workpiece detection, aiming to solve the technical problems of low measurement accuracy and poor real-time performance. It includes: using multiple optical paths for parallel measurement, each optical path can obtain independent distance information, and the measurement accuracy is higher; detecting the position of the workpiece based on the optical path, it is not easily affected by the reflection of the workpiece surface. For hollow workpieces, the second acquisition method is obtained based on the grating module. The dimensional contour size will not be affected by the hollow structure; at the same time, the grating collection frequency is high and the data processing cycle is short, which can realize real-time monitoring of the workpiece size.

Description

Workpiece position detection system

Technical field

The invention relates to a workpiece position detection system and belongs to the technical field of workpiece detection.

Background technique

Usually in the coating production line, the position of the workpiece needs to be detected to ensure that it has been placed correctly before spraying, otherwise the spraying effect will be affected. The mainstream in the industry uses laser ranging technology and radar ranging to detect whether the position of the workpiece is accurate. When implementing the existing solution, the inventor found that when the ranging technology measured the hollow workpiece, the laser beam or radar wave may pass through the hollow part, resulting in The measurement error is very large, so the measurement accuracy is not high; laser ranging technology is greatly affected by the optical characteristics of the workpiece surface, such as surface gloss, which will affect the measurement results; the ranging technology has a slow response speed, making it difficult to achieve real-time monitoring of the workpiece. Therefore, the existing workpiece position detection system has poor measurement accuracy and real-time performance.

Contents of the invention

The purpose of the embodiments of the present disclosure is to overcome the deficiencies in the existing technology and provide a workpiece position detection system with high measurement accuracy and strong real-time performance.

In order to achieve the above objectives, the embodiments of the present disclosure are achieved by adopting the following technical solutions:

In a first aspect, an embodiment of the present disclosure provides a workpiece position detection device, including:

A grating module includes a plurality of light emitters and a plurality of light receivers corresponding to the light emitters; when the workpiece passes through the grating module, the light receivers are blocked from receiving the light from the light emitters;

The host computer module is electrically connected to the grating module.

In some embodiments of the first aspect, the grating module includes at least one one-dimensional strip grating, and the distribution direction of the one-dimensional strip grating is perpendicular to the moving direction of the workpiece.

In some embodiments of the first aspect, an image acquisition module for acquiring an image of the workpiece is further included, and the image acquisition module is electrically connected to the host computer module.

In the second aspect, embodiments of the present disclosure also provide a workpiece position detection method, which is executed by the host computer module.

Obtain the light blocking sequence data of the grating module;

Obtain the two-dimensional outline size based on the light blocking sequence data;

Obtain the error between the 2D profile size and the standard size of the workpiece;

In response to the error reaching the threshold, it is determined that the position of the workpiece is abnormal.

In some embodiments of the second aspect, obtaining an image of the workpiece;

Determine the type of workpiece based on the workpiece image;

Set the standard size of the workpiece according to the type.

In some embodiments of the second aspect,

The acquisition period of the grating module = the spacing between adjacent one-dimensional striped gratings/workpiece speed.

In some embodiments of the second aspect, obtaining the two-dimensional outline size according to the light blocking sequence data includes,

Arrange the light blocking sequence data with the acquisition period as the coordinate axis to obtain a two-dimensional image;

Find pixels blocked by light in a two-dimensional image;

Connect pixels to form the outline of the workpiece.

In some embodiments of the second aspect, it further includes that the two-dimensional image is a pixel image, the light blocking data of a single photoreceptor is a pixel, and the pixel value of the pixel is set according to the light blocking data value.

In some embodiments of the second aspect, the method further includes removing pixels in the two-dimensional image that are blocked by the chain light.

Compared with the prior art, the beneficial effects achieved by the embodiments of the present disclosure are:

The workpiece position detection device and workpiece position detection method provided by the embodiments of the present disclosure use multiple optical paths for parallel measurement. Each optical path can obtain independent distance information, and the measurement accuracy is higher; the workpiece position is detected based on the optical path and is not susceptible to reflection from the workpiece surface. Impact: For hollow workpieces, the two-dimensional outline size obtained from the grating module will not be affected by the hollow structure; at the same time, the grating acquisition frequency is high and the data processing cycle is short, which can realize real-time monitoring of the workpiece size.

Description of drawings

In order to explain the embodiments of the present disclosure or the technical solutions in the prior art more clearly, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are only These are some embodiments of the present disclosure. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without exerting creative efforts.

Figure 1 is a schematic side view of the workpiece in a normal position in an embodiment of the present disclosure;

Figure 2 is a schematic side view of the workpiece in Figure 1 in an inclined position;

Figure 3 is a schematic structural diagram of a workpiece position detection device provided by an embodiment of the present disclosure;

Figure 4 is a flow chart of a workpiece position detection method provided by an embodiment of the present disclosure;

Figure 5 is a schematic diagram of a workpiece passing through a grating module when using the workpiece position detection device provided by an embodiment of the present disclosure;

Figure 6 is a simulated image containing the two-dimensional outline size of the workpiece obtained based on the light blocking sequence data generated by the workpiece passing through the grating module;

Figure 7 is a schematic diagram of a workpiece passing through a grating module when using the workpiece position detection device provided by an embodiment of the present disclosure;

Figure 8 is a flow chart of a workpiece position detection method provided by an embodiment of the present disclosure;

In the picture: 1-Grating module; 1.1-Light emitter; 1.2-Light receiver; 2-Workpiece; 2.1-Chain; 3-Host computer module; 4-Alarm module; 5-Image acquisition module; 6-Display module; Figure The arrow in 5 is the moving direction of the workpiece.

Detailed ways

The technical solution of the present invention will be described in detail below through the accompanying drawings and specific examples. It should be understood that the embodiments of the present application and the specific features in the embodiments are a detailed description of the technical solution of the present application, rather than a limitation of the technical solution of the present application. If there is no conflict, the embodiments of the present application and the technical features in the embodiments can be combined with each other.

Embodiment 1

This embodiment provides a workpiece position detection system. The workpiece position detection system includes a workpiece position detection device and a workpiece position detection method.

Referring to Figures 1 and 2, the perspective of Figures 1 and 2 is a side view. This embodiment takes spraying processing as an example. The workpiece 2 is lifted by the chain 2.1 and prepared to be transported to the spraying station. The workpiece 2 is measured from the side of the workpiece 2 The dimensions are width a1 and length b1. The position of workpiece 2 in Figure 1 is normal, a1=674cm, b1=1919cm. The position of workpiece 2 in Figure 2 is tilted, a1=877cm, b1=1749cm. It is not difficult for those skilled in the art to see that, The tilted position of the workpiece 2 causes changes in its observed two-dimensional dimensions a1, b1 and contour area.

Referring to FIG. 3 and FIG. 5 , the workpiece position detection system provided by the embodiment of the present disclosure includes a workpiece position detection device, including a grating module 1 and a host computer module 3 . The grating module 1 includes a plurality of light emitters 1.1 and a plurality of light receivers 1.2 corresponding to the light emitters 1.1; when the workpiece 2 passes through the grating module 1, the light receivers 1.2 are blocked from receiving the light of the light emitters 1.1. Optionally, in this embodiment, each emitter 1.1 has a corresponding photoreceiver 1.2, and a light path from the emitter 1.1 to the photoreceiver 1.2 is formed between the emitter 1.1 and the photoreceiver 1.2. When the workpiece 2 passes through the grating module At 1 o'clock, part of the light path is blocked. Optionally, in this embodiment, each light path from the emitter 1.1 to the light receiver 1.2 is parallel to each other to form a light curtain. The way in which the workpiece 2 passes through the grating module 1 includes being suspended by the chain 2.1 as shown in Figures 1 and 2, driven by the chain 2.1 through the grating module 1 and blocking the light path, or the workpiece 2 can be placed on the conveyor belt and the grating module 1 is installed on the conveyor belt to block the light path when the workpiece 2 passes; in short, the grating module 1 is arranged on the transportation path of the workpiece 2.

The host computer module 3 is electrically connected to the grating module 1 and is used to collect the signal of the light receiver 1.2 collected at a certain frequency. The signal contains information about whether the light receiver 1.2 receives the light from the light point 1.1 or light intensity information; The signal of the receiver 1.2 can be collected by the grating module 1 by itself, organized into light blocking sequence data and then acquired by the host computer module 3, or the host computer module 3 can control the grating module 1 to collect the signal of the light receiver 1.2.

Figure 4 is a flow chart of the workpiece position detection method in Embodiment 1 of the present invention. This flow chart only shows the logical sequence of the method described in this embodiment. On the premise that there is no conflict with each other, in other possible embodiments of the present invention, the shown or Describe the steps.

The workpiece position detection system provided by the embodiment of the present disclosure includes a workpiece position detection method, which is executed by the host computer module 3, including:

Obtain the light blocking sequence data of grating module 1. The light blocking sequence data includes the signal of each photoreceiver 1.2 during the acquisition period of each grating module 1.

Obtain the two-dimensional outline dimensions from the light-blocking sequence data. Optionally, in some embodiments, referring to Figure 5, the workpiece 2 passes through the grating module 1, the light path corresponding to each photoreceiver 1.2 is blocked to varying degrees, and the host computer module 3 converts the light blocking sequence data into a usable To perform image processing on a simulated image, the signal of each photoreceptor 1.2 in each acquisition cycle of the grating module 1 is converted into a pixel, and different pixel values are set according to the different signals of the photoreceptor 1.2. All pixels constitute the simulation of the workpiece 2 The image reflects the shape and outline of the workpiece 2 through pixel values. Referring to Figure 6, the corresponding pixels where the signal of the photoreceptor 1.2 is blocked and the light is blocked are selected through a rectangular frame.

Obtain the error between the 2D contour dimensions and the standard size of workpiece 2. Optionally, in this embodiment, the rectangular frame mentioned above is measured. Referring to the measurement forms of a1 and b1 in Figures 1 and 2, the two-dimensional outline dimensions include length and width. The length and width are related to the workpiece. 2 Compare the length and width measured by the workpiece position detection device in the standard position. Optionally, in some embodiments, the two-dimensional outline size is obtained by measuring the length and inclination of each side of the simulated image of the workpiece 2 , and the two-dimensional outline size includes the length and inclination of each side of the simulated image of the workpiece 2 .

In response to the error reaching the threshold, it is determined that the position of the workpiece 2 is abnormal. When the error between the length and width of the simulated image of workpiece 2 and the standard size of workpiece 2 is less than the set threshold, for example, the difference between the length and width is only one pixel each, then this error is considered acceptable. Then drive the workpiece 2 into the spraying station; when the error between the length and width of the simulated image of the workpiece 2 and the standard size of the workpiece 2 is greater than the set threshold, this error is considered unacceptable and can be controlled. The chain 2.1 swings to correct the position of the workpiece 2 until the error detected by the workpiece position detection system is less than the threshold. If the position of the workpiece 2 shown in Figure 5 is an accurate posture, when the position of the workpiece 2 is tilted, the tilted workpiece 2 passes through the grating module 1, and the host computer module 3 obtains the two parameters based on the light blocking sequence data of the grating module 1. The dimensional outline size will be larger than the standard size shown in Figure 6.

Optionally, in some embodiments, two grating modules 1 are arranged, and their light paths are orthogonal to each other, so that the two-dimensional contours from the two viewing angles can be integrated into the three-dimensional contour of the workpiece 2 .

Referring to Figure 6, it is easy for those skilled in the art to know that whether the workpiece 2 is hollowed out or not does not prevent the edge of the workpiece 2 from blocking the light path, nor does it affect the two-dimensional outline size obtained based on the edge of the workpiece 2 in the simulated image; the reflection of the workpiece 2 is consistent with No, it will not affect the effect of blocking the light path.

Embodiment 2

This embodiment provides a workpiece position detection system. The workpiece position detection system includes a workpiece position detection device and a workpiece position detection method. It is technically improved upon the first embodiment to improve technical effects.

Referring to FIG. 5 , optionally, in this embodiment, the grating module 1 includes at least one one-dimensional strip grating, and the distribution direction of the one-dimensional strip grating is perpendicular to the moving direction of the workpiece 2 . Optionally, in this embodiment, the grating module 1 is only a one-dimensional strip grating, and the light emitter 1.1 and the light receiver 1.2 are respectively located at both ends of the transport path of the workpiece 2. The formed optical path can control the movement process of the workpiece 2. Scan every interface in the screen. In order to ensure that the two-dimensional contour of the workpiece 2 will not be compressed/stretched, optionally, in this embodiment, the acquisition period of the grating module 1 = the spacing between adjacent one-dimensional striped gratings/workpiece speed; when according to After the simulated image is obtained from the light blocking sequence data, the two-dimensional outline size of the workpiece 2 in the simulated image is basically consistent with the outline size of the workpiece 2 under the viewing angle of the light receiver 1.2; in the image shown in Figure 6, the pixels in the two dimensions are The arrangement spacing is the same. When the acquisition period ≠ the spacing between adjacent one-dimensional stripe gratings/workpiece speed, adaptive spacing adjustments should be made to the corresponding pixels of the light blocking sequence data of adjacent acquisition periods. To ensure that the two-dimensional outline size of workpiece 2 in the simulation image will not be compressed/stretched and deformed.

Referring to Figure 7, compared to the one-dimensional strip grating shown in Figure 5, the grating module 1 in Figure 7 includes two mutually perpendicular one-dimensional strip gratings. The two light paths of the grating module 1 in Figure 7 are perpendicular to each other. , and is also perpendicular to the movement direction of the workpiece 2. The workpiece position detection system in Figure 7 can simultaneously detect the two-dimensional outline dimensions of the workpiece 2 in two directions, and thereby detect the three-dimensional position of the workpiece 2.

The first embodiment mentioned that the two-dimensional outline size is obtained based on the light blocking sequence data. Optionally, in this embodiment, it includes:

Arrange the light blocking sequence data with the acquisition period as the coordinate axis to obtain a two-dimensional image; optionally, the two-dimensional image is a pixel image, and the light blocking data of a single photoreceptor 1.2 is a pixel point. According to the light blocking The data value sets the pixel value of the pixel. In this embodiment, specifically, the light blocking information of the light receiver 1.2 is arranged in order of the position of the light receiver 1.2. 0 represents the light blocking, 1 represents the light not blocked, and the light blocking information is Arrange to form light-blocking sequence data (one-dimensional information), and light-blocking sequence data of different acquisition periods are sorted in order; the host computer module 3 reads the above-mentioned light-blocking sequence data, with time as the first coordinate axis, (This embodiment sets the grating module 1 to only be a one-dimensional strip grating) Taking the arrangement order of the light blocking sequence data as the second coordinate axis, mark 0 as blank and mark 1 as black, as shown in Figure 6 2D image shown. Optionally, in this embodiment, the host computer module 3 obtains several data packets from the grating module 1. The data packets contain several bytes of data, and each byte of 8-bit data corresponds to each of eight photoreceptors 1.2. Clear light blocks information.

Find pixels in a 2D image that are blocked by light.

Referring to the dotted frame in Figure 6, connect the pixels to form the outline of workpiece 2. Optionally, in this embodiment, by connecting each black pixel, the projection outline blocked when the workpiece 2 passes through the grating module 1 can be restored.

Optionally, in this embodiment, remove the pixels blocked by the chain 2.1 in the two-dimensional image, that is, the black pixels generated by the light blocking information generated after the chain 2.1 blocks the light receiver 1.2, and replace these black pixels As white pixels, retain the simulated image with only the outline of workpiece 2.

Embodiment 1 mentions obtaining the error between the two-dimensional outline size and the standard size of the workpiece 2. In addition to human identification input, the standard size of the workpiece 2 can optionally be input. Optionally, in this embodiment, the workpiece position detection device also includes: The image acquisition module 5 acquires the image of the workpiece 2. The image acquisition module 5 is electrically connected to the host computer module 3. Correspondingly, the workpiece position detection method also includes: acquiring the workpiece image; judging the type of the workpiece 2 according to the workpiece image; Determine the standard size of workpiece 2. Optionally, in some embodiments, the image acquisition module 5 is used to collect images of the workpiece 2, establish a workpiece type picture database, mark the sample pictures with type labels, construct a picture-label pair data set, and construct a CNN network model. After completing the training of the model, the images to be recognized are forward propagated, and the one with the highest category probability is output as the recognition result.

Optionally, in this embodiment, the speed of the workpiece 2 passing through the grating module 1 is uniform.

Optionally, in this embodiment, the workpiece position detection device also includes an alarm module 4. The host computer module 3 is electrically connected to the alarm module 4. In response to the abnormal position of the workpiece 2, the alarm module 4 issues an alarm and the personnel After receiving the alarm, manually adjust the position of workpiece 2.

Optionally, in this embodiment, referring to FIG. 3 , the workpiece position detection device also includes a display module 6 electrically connected to the host computer module 3 for displaying the two-dimensional outline dimensions of the workpiece 2 .

Referring to Figure 8, another way to use the workpiece position detection device is to move the workpiece 2 on the assembly line through the conveyor belt and pass the grating module 1. The host computer module 3 controls the grating module 1 to scan the host computer module 3; after the scanning is completed, the host computer module The machine module 3 generates a pixel image based on the light blocking sequence data, and identifies and removes the chain 2.1 in the pixel image; after the scanning is completed, the image acquisition module 5 collects images of the workpiece 2, and the host computer module 3 determines the type of the workpiece 2, and based on The type sets the standard size of the workpiece 2; then, the two-dimensional outline size is calculated based on the pixel image, and whether the position of the workpiece 2 is abnormal is judged; finally, the subsequent painting work or the position correction of the workpiece 2 is carried out based on the judgment results.

The workpiece position detection system provided by this embodiment has higher measurement accuracy. The workpiece position detection device adopts multiple optical paths for parallel measurement. Each optical path can obtain independent distance information, and the measurement resolution is higher; it is suitable for hollow workpiece measurement, because the workpiece The position detection device measures the maximum contour size of the workpiece 2, so there will be no obvious error due to the hollow structure of the workpiece 2; real-time monitoring of the workpiece size is achieved. Due to the high acquisition frequency of the grating module 1 and the short data processing cycle, real-time tracking is possible Changes in the size of the workpiece; not affected by the optical properties of the workpiece surface. Since grating distance measurement is achieved by transmitting and receiving optical signals, that is, detecting the on-off of the light path, it does not depend on the optical properties of the workpiece surface and will not be affected by the infrared rays of the workpiece. Factors such as poor reflectivity affect the measurement results; the system responds quickly, and once a dimensional error is detected, the workpiece position can be corrected in time through an alarm; the cost is low, the cost of grating components is lower than that of a single-point laser sensor, and the overall system investment is smaller; easy to install, The grating is small in size and can be flexibly installed on complex production lines. The workpiece position detection system provided in this embodiment improves the accuracy and real-time performance of position detection, and effectively meets the needs of production line automation.

Those skilled in the art will understand that embodiments of the present application may be provided as methods, systems, or computer program products. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment that combines software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each process and/or block in the flowchart illustrations and/or block diagrams, and combinations of processes and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing device to produce a machine, such that the instructions executed by the processor of the computer or other programmable data processing device produce a use A device for realizing the functions specified in a process or processes in a flowchart and/or a block or blocks in a block diagram.

These computer program instructions may also be stored in a computer-readable memory that causes a computer or other programmable data processing apparatus to operate in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including the instruction means, the instructions The device implements the functions specified in a process or processes in the flowchart and/or in a block or blocks in the block diagram.

These computer program instructions may also be loaded onto a computer or other programmable data processing device, causing a series of operating steps to be performed on the computer or other programmable device to produce computer-implemented processing, thereby executing on the computer or other programmable device. Instructions provide steps for implementing the functions specified in a process or processes of a flowchart diagram and/or a block or blocks of a block diagram.

The above are only preferred embodiments of the present invention. It should be noted that those of ordinary skill in the art can also make several improvements and modifications without departing from the technical principles of the present invention. These improvements and modifications It should also be regarded as the protection scope of the present invention.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", " The orientations or positional relationships indicated by "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and The simplified description is not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as a limitation of the present invention. In the description of the present invention, it should be noted that, unless otherwise clearly stated and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection. Connection, or integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific situations.

The above are only preferred embodiments of the present invention. It should be noted that those of ordinary skill in the art can also make several improvements and modifications without departing from the technical principles of the present invention. These improvements and modifications It should also be regarded as the protection scope of the present invention.

Claims (9)

1. The workpiece position detecting device is characterized by comprising,

a grating module (1) comprising a plurality of light emitters (1.1) and a plurality of light receptors (1.2) corresponding to the light emitters (1.1); blocking the light receiver (1.2) from receiving the light of the light emitter (1.1) when the workpiece (2) passes through the grating module (1);

and the upper computer module (3) is electrically connected with the grating module (1).

2. The workpiece position detection device according to claim 1, characterized in that the grating module (1) comprises at least one-dimensional linear grating, the direction of distribution of which is perpendicular to the direction of movement of the workpiece (2).

3. The workpiece position detection device according to claim 1, further comprising an image acquisition module (5) for acquiring an image of the workpiece (2), the image acquisition module (5) being in electrical signal connection with the upper computer module (3).

4. The workpiece position detection method is executed by the upper computer module (3) and is characterized in that,

acquiring light transmission blocking sequence data of the grating module (1);

acquiring a two-dimensional outline size according to the light transmission blocking sequence data;

acquiring an error between the two-dimensional contour dimension and a standard size of the workpiece (2);

in response to the error reaching a threshold, a positional abnormality of the workpiece (2) is determined.

5. The method for detecting a position of a workpiece according to claim 4, wherein,

acquiring a workpiece image;

judging the type of the workpiece (2) according to the workpiece image;

the standard size of the workpiece (2) is set according to the type.

6. The method for detecting a position of a workpiece according to claim 4, wherein,

acquisition period of the grating module (1) =spacing between adjacent one-dimensional linear gratings/workpiece speed.

7. The method of detecting a position of a workpiece as defined in claim 6, wherein acquiring a two-dimensional profile from the light-passing blocking sequence data comprises,

arranging the light-transmitting blocking sequence data by taking the acquisition period as a coordinate axis to obtain a two-dimensional image;

finding out pixels blocked by light in the two-dimensional image;

the pixels are connected to form the outline of the workpiece (2).

8. The method according to claim 7, further comprising setting a pixel value of a pixel point based on the light-passing blocking data value of the single light receiver (1.2) as the pixel image with the two-dimensional image being the pixel image.

9. The method of detecting the position of a workpiece according to claim 7, further comprising removing pixels in the two-dimensional image that are blocked by the light passing through the chain (2.1).