Screw floating lock detection method and equipment

Abstract

The invention provides a screw floating lock detection method and equipment, and the method comprises the following steps: obtaining the image information of a to-be-detected member through a 3D infrared scanning camera, the to-be-detected member comprising a mounting plate and a screw locked on the mounting plate; according to the image information, the outer contour of a nut of the screw and a mounting plate exposed area are recognized, and the mounting plate exposed area is an area where no screw is arranged; selecting a detection point in the outer contour, acquiring first height information of the detection point, selecting a reference point on the exposed area of the mounting plate, and acquiring second height information of the reference point; obtaining the protruding height of the screw according to the first height information and the second height information; and judging whether the protruding height of the screw is qualified or not according to the protruding height and preset height information. The screw floating lock detection method has the advantage of high detection efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of screw floating lock detection, and particularly to a screw floating lock detection method and device. Background Art

[0002] During the manufacturing process of products in the domestic consumer electronics industry, it is very difficult to identify whether there is a floating lock phenomenon after the screw is locked and tightened by visual inspection. At present, the mechanical contact measurement and detection method has a low detection efficiency.

[0003] In view of this, it is necessary to provide a new screw floating lock detection method and device to solve or at least alleviate the above technical defects. Summary of the Invention

[0004] In view of the above problems, the present invention provides a screw floating lock detection method and device, aiming to solve the technical problem of low detection efficiency of screw floating lock in related technologies. According to some embodiments of the present invention, a screw floating lock detection method is provided. The screw floating lock detection method includes: Obtaining image information of a workpiece to be detected through a 3D infrared camera. The workpiece to be detected includes a mounting plate and a screw locked to the mounting plate; Identifying the outer contour of the nut of the screw and the exposed area of the mounting plate according to the image information, where the exposed area of the mounting plate is the area where no screw is provided; Selecting detection points within the outer contour and obtaining the first height information of the detection points, selecting reference points on the exposed area of the mounting plate and obtaining the second height information of the reference points; Obtaining the protruding height of the screw according to the first height information and the second height information; Judging whether the protruding height of the screw is qualified according to the protruding height and preset height information.

[0005] In some embodiments, the step of selecting detection points within the outer contour includes: Obtaining the center point of the nut according to the outer contour, making a straight line through the center point, and selecting two detection points at positions close to the outer contour on the straight line; wherein, the two detection points are respectively located on both sides of the center point.

[0006] In some embodiments, the step of selecting detection points within the outer contour includes: Obtaining the center point of the nut according to the outer contour, making a detection circle with the center point as the center, the detection circle is within the outer contour and close to the outer contour, and selecting a plurality of detection points on the detection circle, and the plurality of detection points are evenly distributed on the detection circle.

[0007] In some embodiments, the distance between the detection point and the outer contour is defined as d, and 0 < d ≤ 2 mm.

[0008] In some embodiments, a plurality of screws are provided on the workpiece to be detected, and the steps of identifying the outer contour of the screw nut and the exposed area of the mounting plate according to the image information include: Identifying the outer contour of the nut of one of the screws according to the image information, obtaining the outer contours of the nuts of the remaining screws according to the relative positional relationship between the remaining screws and one of the screws, and identifying the exposed area of the mounting plate.

[0009] In some embodiments, the number of the reference points is multiple, and the step of selecting reference points on the exposed area of the mounting plate includes: Selecting the corresponding reference points at positions on the exposed area of the mounting plate close to the outer contour.

[0010] In some embodiments, the step of obtaining the first height information of the detection point includes: Respectively obtaining the height values of the detection points within each outer contour, and taking the maximum height value as the first height information.

[0011] In some embodiments, the step of obtaining the first height information of the detection point includes: Respectively obtaining the height values of the detection points within each outer contour, obtaining the average height value of the detection points according to the height values, and taking the average height value as the first height information.

[0012] In some embodiments, the number of the detection points is multiple. After the step of judging whether the protruding height of the screw is qualified according to the protruding height and the preset height information, the following steps are further included: Obtaining the maximum height value and the minimum height value of the multiple detection points within the outer contour, and obtaining a height difference according to the maximum height value and the minimum value; Judging whether the screw installation is qualified according to the height difference and the preset height difference.

[0013] In some embodiments, the step of judging whether the protruding height of the screw is qualified according to the protruding height and the preset height information includes: If it is qualified, directly enter the next process; If it is unqualified, obtaining the two-dimensional code information of the workpiece to be detected and sending it to the controller, and the controller controls the gripper to take away the unqualified workpiece to be detected.

[0014] In some embodiments, before the step of obtaining the image information of the workpiece to be detected by the 3D infrared scanning camera, the following steps are further included: The in-place detection signal is received, and the 3D infrared camera is turned on according to the in-place detection signal.

[0015] According to some embodiments of the present invention, the present invention provides a screw floating lock detection device, which adopts the screw floating lock detection method described in any one of the above, and includes: a base, a first driving member, a mounting bracket, and a 3D infrared camera. The first driving member is mounted on the base, the mounting bracket is connected to the first driving member, the 3D infrared camera is mounted on the mounting bracket, the 3D infrared camera includes a transmitting member and a receiving member. The transmitting member is used to receive the in-place detection signal and emit infrared light to irradiate the workpiece to be detected, and the receiving member is used to receive the light beam reflected by the workpiece to be detected to obtain the image information of the workpiece to be detected.

[0016] In the above solution, the image information of the workpiece to be detected is obtained through a 3D infrared camera. The workpiece to be detected includes a mounting plate and a screw attached to the mounting plate. The outer contour of the screw nut and the exposed area of the mounting plate are identified according to the image information. Among them, the exposed area of the mounting plate is the area where no screw is provided. Detection points are selected within the outer contour, and the first height information of the detection points is obtained. A reference point is selected on the exposed area of the mounting plate, and the second height information of the reference point is obtained. The protruding height of the screw is obtained according to the first height information and the second height information. Whether the protruding height of the screw is qualified is judged according to the protruding height and the preset height information. The invention has the advantage of high detection efficiency.

[0017] The above description is only an overview of the technical solution of the present invention. In order to be able to understand the technical means of the present invention more clearly, it can be implemented according to the content of the description. And in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable, the following specifically describes the embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] By reading the detailed description of the preferred embodiments below, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention. And in all the drawings, the same reference numerals are used to represent the same components. In the drawings: Figure 1 It is a schematic flow chart of the screw floating lock detection method according to the first embodiment of the present invention; Figure 2 It is a schematic flow chart of the screw floating lock detection method according to the second embodiment of the present invention; Figure 3 It is a schematic flow chart of the screw floating lock detection method according to the third embodiment of the present invention; Figure 4 It is a schematic flow chart of the screw floating lock detection method according to the fourth embodiment of the present invention; Figure 5 Schematic flow diagram of the screw floating lock detection method according to the fifth embodiment of the present invention; Figure 6 Schematic flow diagram of the screw floating lock detection method according to the sixth embodiment of the present invention; Figure 7 Schematic flow diagram of the screw floating lock detection method according to the seventh embodiment of the present invention; Figure 8 Schematic flow diagram of the screw floating lock detection method according to the eighth embodiment of the present invention; Figure 9 Schematic diagram of the image information obtained by the screw floating lock detection method according to the embodiments of the present invention; Figure 10 Schematic structural diagram of the screw floating lock detection device according to the embodiments of the present invention.

[0019] The reference numerals in the specific embodiments are as follows: 100, screw floating lock detection device; 10, base; 20, first driving member; 30, mounting bracket; 40, 3D infrared scanner; 200, assembly line; 300, workpiece to be detected; 310, mounting plate; 320, nut; A, detection point; B, reference point. Specific embodiments

[0020] The embodiments of the technical solution of the present invention will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solution of the present invention more clearly, and therefore are only examples and cannot be used to limit the protection scope of the present invention.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention; the terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above drawings are intended to cover non-exclusive inclusion.

[0022] In the description of the embodiments of the present invention, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order or primary-secondary relationship of the indicated technical features. In the description of the embodiments of the present invention, "a plurality" means more than two unless otherwise specifically defined.

[0023] References to "embodiments" in this specification mean that specific features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of the invention. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment each time, nor are they independent or alternative embodiments mutually exclusive of other embodiments. Those skilled in the art will understand explicitly and implicitly that the embodiments described herein can be combined with other embodiments.

[0024] In the description of the embodiments of the present invention, the term "and / or" is merely a description of the association relationship between associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Additionally, the character " / " in this text generally represents an "or" relationship between the associated objects before and after.

[0025] In the description of the embodiments of the present invention, the term "plurality" refers to two or more (including two). Similarly, "multiple groups" refers to two or more groups (including two groups), and "multiple pieces" refers to two or more pieces (including two pieces).

[0026] In the description of the embodiments of the present invention, the orientation or positional relationship indicated by technical terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the embodiments of the present invention.

[0027] In the description of the embodiments of the present invention, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", "connection", "fixation", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can also be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0028] During the screw locking process, the floating lock phenomenon is a common problem. Whether using an ordinary air screwdriver or an automatic screw locking machine, it is possible to encounter a situation where the torque reaches the preset target, but the screw is still not locked in place. This situation is usually referred to as floating lock, floating height, or floating nail. Floating lock means that the screw is not locked in place properly, which can be that the height of the nut of the screw is relatively high, or the nut is installed obliquely due to the inclined installation of the screw rod. In related technologies, generally, a mechanical measurement method is used to measure the height of the nut relative to the mounting plate with a vernier caliper, and this manual detection method has low detection efficiency.

[0029] For this reason, the applicant provides a method for detecting screw floating lock.

[0030] Refer to Figure 1 , Figure 1 which is a schematic flow chart of the screw floating lock detection method according to the first embodiment of the present invention. The screw floating lock detection method includes: S100, obtaining image information of the workpiece 300 to be detected through the 3D infrared camera 40. The workpiece 300 to be detected includes a mounting plate 310 and screws locked to the mounting plate 310; The workpiece 300 to be detected here includes the mounting plate 310 and the screws locked to the mounting plate 310. The mounting plate 310 can be a printed circuit board or a substrate. Multiple components can be arranged on the mounting plate 310. The screws include nuts 320 and screw rods. Generally, the screw rods are locked inside the mounting plate 310, and the nuts 320 are exposed on the mounting plate 310. The purpose of this application is to determine whether the screw locking is qualified, that is, whether there is a floating lock phenomenon, by measuring the height of the nut 320 exposed or protruding from the mounting plate 310. Unqualified situations include that the screw is locked too loosely and the screw is locked eccentrically, resulting in the nut 320 tilting to one side, etc. The 3D infrared camera 40 can obtain the image information of the workpiece 300 to be detected. The image information here can include 3D images, which can display the height characteristics of the nut 320. During the scanning process of the 3D infrared camera 40, the 3D features can also be converted into 2.5D graphics, which is convenient for the positioning and guiding calculation of the screw position.

[0031] S200, identifying the outer contour of the nut 320 of the screw and the exposed area of the mounting plate according to the image information, where the exposed area of the mounting plate is the area where no screw is provided; It should be noted that when only screws are arranged on the mounting plate 310, the exposed area of the mounting plate refers to the area where no screw is provided; for the mounting plate 310 where other components are also arranged, the exposed area of the mounting plate also refers to the area where no screw and other components are provided. According to the captured image information and in combination with the known outer contour of the nut 320, the controller can obtain the position of the outer contour of the nut 320 of the screw. If other areas are a plate-like object, it can be identified as the exposed area of the mounting plate.

[0032] In S300, a detection point A is selected within the outer contour, and the first height information of the detection point A is obtained. A reference point B is selected on the exposed area of the mounting plate, and the second height information of the reference point B is obtained; Combined with reference to Figure 9 , Figure 9 Shown in the figure is a schematic diagram with a circular outer contour and two selected detection points A. It should be noted that the actually obtained image will also reflect height features. The points within the outer contour are the points on the nut 320, and they are the points on the side of the nut 320 away from the screw, that is, the points on the side of the nut 320 away from the mounting plate 310. Selecting the points within the outer contour means selecting the points on the nut 320 as the detection point A. Since a 3D infrared scanning camera 40 is used, the first height information of the detection point A can be obtained. The first height information includes the height coordinates of the detection point A. A reference point B is selected in the exposed area of the mounting plate. The second height information of the reference point B can include the height coordinates of the reference point B. The screw is locked to the mounting plate 310. Here, the reference point B is used as a reference to facilitate obtaining the protruding height of the nut 320 relative to the mounting plate 310 in the subsequent steps. At the same time, it should be noted that one or more detection points A can be selected within the outer contour of a nut 320, and those skilled in the art can set it according to actual needs.

[0033] In S400, the protruding height of the screw is obtained based on the first height information and the second height information; In this application, the floating lock phenomenon of the screw is determined by the protruding height of the nut 320. The protruding height of the nut 320 in this application and the protruding height of the screw express the same meaning. Floating lock can include that the screw is not tightly locked, resulting in an excessive protruding height of the nut 320; or the screw is locked obliquely, resulting in a large protruding height at some positions of the nut 320 and a small protruding height at some positions. Of course, the unqualified situation also includes that the screw is locked too tightly, resulting in a too small protruding height, and this application can also detect it. It should be noted that the protruding height of the screw is the height of the top surface of the nut 320, that is, the side of the nut 320 facing away from the mounting plate 310 relative to the mounting plate 310. The first height information includes the height coordinates of the detection point A on the top surface of the nut 320, and the second height information includes the height coordinates of the mounting plate 310. Subtracting the two heights can obtain the protruding height of the screw.

[0034] In S500, it is determined whether the protruding height of the screw is qualified according to the protruding height and the preset height information.

[0035] After the 3D infrared camera 40 obtains the image information, it can send it to the controller. The controller can calculate the protruding height, and a qualified protruding height range is preset in the controller, which is called the preset height information here. If the protruding height range is within the preset height information range, it is determined that the screw locking is qualified and there is no floating lock phenomenon. If the protruding height range is outside the preset height information range, it is determined that the screw locking is unqualified and there is a floating lock phenomenon.

[0036] In the above embodiment of the present invention, the image information of the workpiece 300 to be detected is obtained by the 3D infrared camera 40. The outer contour of the nut 320 of the screw and the exposed area of the mounting plate are identified according to the image information. The detection point A is selected within the outer contour, and the first height information of the detection point A is obtained. The reference point B is selected on the exposed area of the mounting plate, and the second height information of the reference point B is obtained. The protruding height of the screw is obtained according to the first height information and the second height information, and whether the protruding height of the screw is qualified is judged according to the protruding height and the preset height information. In this embodiment, the image information is obtained by the 3D infrared camera 40 and sent to the controller. The controller can obtain the protruding height of the nut 320 according to the image information and judge whether there is a floating lock phenomenon of the screw. The automatic detection method has high detection efficiency.

[0037] Refer to Figure 2 , Figure 2 is a schematic flowchart of the screw floating lock detection method according to the second embodiment of the present invention. The step of selecting the detection point A within the outer contour includes: S301, obtain the center point of the nut 320 according to the outer contour, draw a straight line through the center point, and select two detection points A at positions close to the outer contour on the straight line; wherein, the two detection points A are respectively located on both sides of the center point.

[0038] The shape of the outer contour is also the shape of the outer periphery of the nut 320, which is generally a regular image, such as a circle or a regular hexagon. The center point of the nut 320 can be obtained according to the shape of the outer contour. Combine and refer to Figure 9, when the outer contour is circular, the center point is the center of the circle. Draw a straight line through the center point to intersect the opposite sides of the outer contour. Taking the center point as the center of the circle as an example, the straight line drawn can be the diameter. Select two detection points A at positions close to the outer contour at both ends of the diameter, and the two points are respectively located on both sides of the center point. This embodiment is particularly applicable to detecting the inclination of the nut 320. When there is floating locking, the heights of each point on the nut are not completely consistent. Due to the inclination of the nut 320, one side is higher and the other side is lower. In the case of only detecting one point, if the lower point is selected, there may be a misjudgment that the screw does not have the floating locking phenomenon. Therefore, the two selected points are respectively located on both sides of the center point. The reason for selecting the position close to the outer contour is that the position of the outer contour is generally the highest or lowest point of the inclined part relative to the center point, so the detection result is more accurate. Moreover, selecting two detection points A can reduce the calculation amount of the controller or the image processing time, greatly improving the detection efficiency. It should be noted that this application is particularly applicable to the detection of flat head screws. Of course, it can also be applicable to the detection of convex nuts 320.

[0039] In the above embodiment of the present invention, two opposite points close to the outer contour are selected as the detection points A, and the selected detection points A are more representative and can improve the detection accuracy.

[0040] Refer to Figure 3 , Figure 3 is a schematic flow chart of the screw floating locking detection method according to the third embodiment of the present invention. The step of selecting the detection point A within the outer contour includes: S302, obtain the center point of the nut 320 according to the outer contour, make a detection circle with the center point as the center of the circle. The detection circle is within the outer contour and close to the outer contour, and select a plurality of detection points A on the detection circle. The plurality of detection points A are evenly distributed on the detection circle.

[0041] This embodiment adopts the embodiment of selecting three or more detection points A within the outer contour. The shape of the outer contour is also the shape of the outer periphery of the nut 320, which is generally a regular image, such as a circle or a regular hexagon. The center point of the nut 320 can be obtained according to the shape of the outer contour. When the outer contour is circular, the center point is the center of the circle. Take a number smaller than the radius of the outer contour as the radius and make a detection circle with the center point as the center of the circle. Generally, due to the inclination of the nut 320, one side is higher and the other side is lower. In the case of only detecting one point, if the lower point is selected, there may be a misjudgment that the screw does not have the floating locking phenomenon. And the highest and lowest points of the inclination are generally located on the outer contour, so the detection circle is set as close to the outer contour as possible, which can improve the detection accuracy. At the same time, to ensure that the selected points can cover as many positions of the nut 320 as possible, a plurality of detection points A can be set to be evenly distributed on the detection circle with equal intervals.

[0042] In the above embodiments of the present invention, by selecting a plurality of detection points A on the detection circle, and the plurality of detection points A are evenly distributed on the detection circle, the detection points A can cover various positions of the nut 320 as much as possible, improving the detection accuracy.

[0043] In some embodiments, the distance between the detection point A and the outer contour is defined as d, then 0 < d ≤ 2 mm.

[0044] The distance between the detection point A and the outer contour here can be regarded as the distance from a point to a circle, that is, the distance from each detection point A to the part of the outer contour closest to itself. As described above, this distance can be set as small as possible, so that the selected detection points A are closer to the outer contour. In this way, not only can the situation where the screw is not properly locked be detected, but it is also more suitable for detecting the situation where the screw is locked obliquely.

[0045] Refer to Figure 4 , Figure 4 which is a schematic flowchart of the screw floating lock detection method according to the fourth embodiment of the present invention. A plurality of screws are provided on the workpiece 300 to be detected. The steps of S200 include: S201, identify the outer contour of the nut 320 of one of the screws according to the image information, obtain the outer contours of the nuts 320 of the remaining screws according to the relative position relationship between the remaining screws and one of the screws, and identify the exposed area of the mounting plate.

[0046] It should be noted that in the actual detection process, in the case of multiple screws, the outer contours of multiple screws can be simultaneously identified according to the image recognition information, so that the heights of multiple screws can be detected at the same time. Compared with laser detection, laser detection needs to scan and detect each nut 320 one by one, while the technical solution of the present application can simultaneously pick up the image information of multiple screws and detect multiple nuts 320 at the same time, and the detection efficiency is significantly improved. However, there will also be a problem. Refer to Figure 9 As shown, due to problems such as the illumination angle or the reflection intensity, there may be dark lines or dark spots on the outer contours of some nuts 320, such as Figure 9As shown in C, the outer contour of the nut 320 is not clear. Those skilled in the art can understand that the installation positions of the respective screws on the mounting plate 310 can be preset in advance, that is, the relative positional relationship of the respective screws is actually determined. Therefore, the present application can obtain a clear outer contour image of the nut 320 in the image information, and the center point of the outer contour can be obtained based on the clear outer contour image of the nut 320. From the coordinates of this center point and the relative positional relationship of the respective screws preset in advance, the position coordinates of the remaining screws, that is, the center point coordinates of the remaining nuts 320, can be obtained, and the outer contour of the nut 320 can be obtained based on the size of the nut 320. Of course, the outer contours of the remaining nuts 320 can also be directly obtained based on the outer contour of one of the nuts 320 and the relative positional relationship. The outer contour of the nut 320 obtained in this way using the relative setting relationship is obtained by calculation rather than image acquisition (except for the first one), and the selection of the first outer contour can select the clearest one based on the outer contours of multiple screws, reducing the risk that the outer contour of the nut 320 is not clear and difficult to accurately identify due to the illumination angle or reflection factor, and further improving the detection accuracy.

[0047] In the above embodiments of the present invention, by identifying the outer contour of the nut 320 of one of the screws through the image information and obtaining the outer contours of the nuts 320 of the remaining screws according to the relative positional relationship between the remaining screws and one of the screws, the detection accuracy can be improved, and the influence on the detection result caused by the unclear outer contour due to the illumination intensity or reflected light can be reduced.

[0048] In some embodiments, the number of the reference points B is multiple, and the step of selecting the reference point B on the exposed area of the mounting plate includes: Select the corresponding reference point B at a position on the exposed area of the mounting plate close to the outer contour.

[0049] For the case where the mounting plate 310 is a flat plate, generally, it is also possible to select one reference point B. However, due to the installation of components, the mounting plate 310 may be partially warped. If all the nuts 320 are calculated based on the same reference point B, there may be inaccurate detection results because we generally judge whether the screw is floating-locked based on the surface of the adjacent mounting plate 310 as a reference. In particular, the mounting plate 310 can also be in the shape of a trapezoidal plate, that is, there are more than two different heights. In this case, different reference points B need to be selected for the detection of whether the screw is floating-locked. Generally speaking, the principle for selecting the reference point B is to select it on the mounting surface corresponding to the screw.

[0050] In the above embodiments of the present invention, by selecting the corresponding reference point B at a position on the exposed area of the mounting plate close to the outer contour, it is ensured that the selection of the reference point B is on the mounting surface corresponding to the corresponding screw, ensuring the measurement accuracy.

[0051] Reference Figure 5 , Figure 5 is a schematic flowchart of the screw floating lock detection method according to the fifth embodiment of the present invention, and the steps of obtaining the first height information of the detection point A include: S310, respectively obtain the height values of each detection point A within each outer contour, and take the maximum height value as the first height information corresponding to the outer contour.

[0052] When the number of screws is multiple, for each screw, after separate detection, individual comparison is performed. Within the outer contour of a nut 320, obtain the height values of each detection point A, and take the maximum height value as the first height information. For the outer contours of other nuts 320, the same calculation is performed. Each outer contour corresponds to a maximum height value, and then the difference between the maximum height values of each outer contour and the second height information is obtained to obtain the protruding height, and it is determined whether each screw is installed qualified respectively. If the maximum height values all meet the requirements, it proves that the screws are not tightened insufficiently. In this embodiment, the maximum height value within the outer contour is selected for calculation, and the calculation process is simple, which is beneficial to improving the detection efficiency.

[0053] Reference Figure 6 , Figure 6 is a schematic flowchart of the screw floating lock detection method according to the sixth embodiment of the present invention, and the steps of obtaining the first height information of the detection point A include: S320, respectively obtain the height values of each detection point A within each outer contour, obtain the average height value of the detection point A according to each height value, and take the average height value as the first height information.

[0054] Sometimes, in the case where the inclination of the screw installation is small, what we are concerned about is whether the average height of each position meets the requirements. If the inclination of the screw installation is small and the average height of each point meets the requirements, it can be considered that most positions of the nut are within the preset range, and then it can be accepted. Therefore, the height values of each detection point A within each outer contour can be obtained, the average value is taken respectively within each outer contour to obtain the average height value, and the average height value is used as the first height information to compare with the height of the reference point B to determine whether the protruding height is qualified.

[0055] By respectively obtaining the height values of each detection point A within each outer contour, obtaining the average height value of the detection point A according to each height value, and taking the average height value as the first height information, the average angle can be used to determine whether the height of the nut 320 is within the qualified range.

[0056] Reference Figure 7 , Figure 7 is a schematic flowchart of the screw floating lock detection method according to the seventh embodiment of the present invention. The number of the detection points A is multiple. After the step of S500, the following steps are further included: S600, obtain the maximum height value and the minimum height value of multiple said detection points A inside the outer contour, and obtain a height difference according to the maximum height value and the minimum value; This embodiment is particularly applicable to determining whether a screw is installed obliquely. Specifically, if the screw is installed obliquely, that is, the nut 320 is inclined, then the minimum height value and the maximum height value will be on opposite sides, and the greater the inclination of the screw, the greater the difference between the maximum height value and the minimum height value. At the same time, a large inclination of the screw also indicates the phenomenon of loose locking where the screw is not properly installed. Taking the selected points as two and the outer contour as a circle as an example, the two selected points are respectively located at positions close to the outer contour of the diameter and on both sides of the center of the circle. At this time, the height difference of the nut 320 can be judged through the maximum height value and the minimum height value, and the height difference reflects the inclination degree of the nut 320. If the inclination degree is serious, it indicates that there is a loose locking situation with the screw.

[0057] S700, determine whether the installation of the screw is qualified according to the height difference and a preset height difference.

[0058] If the height difference is within the range of the preset height difference, it is determined to be qualified; otherwise, it is determined to be unqualified.

[0059] In the above embodiment of the present invention, by obtaining the maximum height value and the minimum height value of multiple said detection points A inside the outer contour, and obtaining a height difference according to the maximum height value and the minimum value to determine whether the screw installation is qualified, this embodiment is particularly applicable to determining whether the inclination degree of the nut 320 exceeds a preset limit.

[0060] In some embodiments, the steps of S500 include: If it is qualified, directly enter the next process; If the product is qualified, directly enter the next process for production.

[0061] If it is unqualified, obtain the two-dimensional code information of the workpiece to be detected 300 and send it to the controller, and the controller controls the gripper to take away the unqualified workpiece to be detected 300. Specifically, in this step, if the detection result is unqualified, the two-dimensional code information of the workpiece to be detected 300 can be obtained through an image recognition device such as a radio frequency identification device and sent to the controller. The controller can identify the corresponding unqualified part according to the two-dimensional code information and control the gripper to remove the unqualified part to prevent it from flowing into the next process. Of course, the image recognition device can also recognize the two-dimensional code information of each workpiece to be detected 300, playing a role in traceability.

[0062] In the above embodiment of the present invention, by obtaining the two-dimensional code information of the workpiece to be detected 300 and sending it to the controller, and the controller controls the gripper to take away the unqualified workpiece to be detected 300, the unqualified parts can be removed in time.

[0063] Refer to Figure 8 , Figure 8 which is a schematic flowchart of the screw floating lock detection method according to the eighth embodiment of the present invention. Before the step of S100, the following steps are further included: S010, receiving a in-place detection signal, and turning on the 3D infrared camera 40 according to the in-place detection signal.

[0064] The in-place detection signal here refers to that when the part to be detected moves to a predetermined position, it touches the magnetic induction switch on the assembly line 200, and the magnetic induction switch sends the in-place detection signal, which is received by the controller. Detecting the in-place detection signal indicates that the part to be detected 300 has moved to the detection position, and the 3D infrared camera 40 can be automatically controlled to start detection.

[0065] By setting the 3D infrared camera 40 to be turned on according to the in-place detection signal, automatic start of detection can be achieved.

[0066] Refer to Figure 10, according to some embodiments of the present invention, the present invention provides a screw floating lock detection device 100, which adopts the screw floating lock detection method of any one of the above, including: a base 10, a first driving member 20, a mounting frame 30 and a 3D infrared camera 40. The first driving member 20 is mounted on the base 10, the mounting frame 30 is connected to the first driving member 20, and the 3D infrared camera 40 is mounted on the mounting frame 30. The 3D infrared camera 40 includes a transmitting member and a receiving member. The transmitting member is used to receive the in-place detection signal and emit infrared light to irradiate the workpiece to be detected 300, and the receiving member is used to receive the light beam reflected by the workpiece to be detected 300 to obtain the image information of the workpiece to be detected 300. The screw floating lock detection device 100 is installed beside the production line 200. There is a tooling on the production line 200, and the workpiece to be detected 300 is placed on the tooling, and the tooling moves on the production line 200. A magnetic induction switch is arranged on the production line 200. When the tooling moves to the detection position, the magnetic induction switch can trigger the in-place detection signal to be sent to the controller, and the controller controls the 3D infrared camera 40 to be turned on. The 3D infrared camera 40 irradiates the workpiece to be detected 300 by emitting infrared light, and the receiving member is used to receive the light beam reflected by the workpiece to be detected 300 to obtain the image information of the workpiece to be detected 300. The first driving member 20 is used to control the height of the 3D infrared camera 40 in the vertical or horizontal direction. Of course, a second driving member and a third driving member can also be provided to respectively adjust the position of the 3D infrared camera 40 in the other two directions in the three-dimensional space. A long strip hole can also be arranged on the mounting frame 30 to finely adjust the height of the 3D infrared camera 40. The stroke can be selected according to the volume and position requirements of different products, and the position can be adjusted through the open touch screen in the electric control system, and precise positioning of 0.001 mm can be achieved to realize full coverage of automatic product scanning and detection. The basic working process of the screw floating lock detection device 100 is as follows: when the workpiece to be detected 300 is transferred to the detection position, the magnetic induction switch sends the in-place detection signal to the controller, and the in-place detection signal is fed back to the controller to trigger the 3D infrared camera 40 to perform screw height detection. The detection data is uploaded to the upper computer for result judgment and data storage. The products with the judgment result of OK are transferred to the next process, and a single cycle of work ends.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the various embodiments of the present invention, and they should all be covered within the scope of the claims and the description of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in each embodiment can be combined in any way. The present invention is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for detecting a screw floating lock, characterized in that The described screw floating lock detection method includes: Obtaining image information of the workpiece to be detected through a 3D infrared camera, where the workpiece to be detected includes a mounting plate and screws attached to the mounting plate; Identifying the outer contour of the nut of the screw and the exposed area of the mounting plate according to the image information, where the exposed area of the mounting plate is the area where no screw is provided; Selecting detection points within the outer contour and obtaining the first height information of the detection points, selecting reference points on the exposed area of the mounting plate and obtaining the second height information of the reference points; Obtaining the protruding height of the screw according to the first height information and the second height information; Judging whether the protruding height of the screw is qualified according to the protruding height and the preset height information.

2. The screw floating lock detection method according to claim 1, wherein, The step of selecting detection points within the outer contour includes: Obtaining the center point of the nut according to the outer contour, drawing a straight line through the center point, and selecting two detection points at positions close to the outer contour on the straight line; where the two detection points are respectively located on both sides of the center point.

3. The screw floating lock detection method according to claim 1, wherein, The step of selecting detection points within the outer contour includes: Obtaining the center point of the nut according to the outer contour, making a detection circle with the center point as the center, the detection circle is within the outer contour and is arranged close to the outer contour, and selecting a plurality of detection points on the detection circle, and the plurality of detection points are evenly distributed on the detection circle.

4. The screw floating lock detection method according to claim 1, characterized in that, Defining the distance between the detection point and the outer contour as d, then 0 < d ≤ 2 mm.

5. The screw floating lock detection method according to claim 1, characterized in that, There are a plurality of screws on the workpiece to be detected, and the step of identifying the outer contour of the nut of the screw and the exposed area of the mounting plate according to the image information includes: Identifying the outer contour of the nut of one of the screws according to the image information, obtaining the outer contours of the nuts of the remaining screws according to the relative position relationship between the remaining screws and one of the screws, and identifying the exposed area of the mounting plate.

6. The screw floating lock detection method according to claim 5, characterized in that, The number of the reference points is multiple, and the step of selecting reference points on the exposed area of the mounting plate includes: Selecting the corresponding reference points at positions close to the outer contour in the exposed area of the mounting plate.

7. The screw floating lock detection method according to any one of claims 2 to 6, characterized in that The number of the detection points is multiple, and the step of obtaining the first height information of the detection points includes: Respectively obtaining the height values of the detection points within each outer contour, and taking the largest height value as the first height information.

8. The screw floating lock detection method according to any one of claims 2 to 6, characterized in that The number of the detection points is multiple, and the step of obtaining the first height information of the detection points includes: Respectively obtaining the height values of the detection points within each outer contour, obtaining the average height value of the detection points according to the height values, and taking the average height value as the first height information.

9. The screw floating lock detection method according to any one of claims 1 to 6, characterized in that, After the step of judging whether the protruding height of the screw is qualified according to the protruding height and the preset height information when the number of the detection points is multiple, the method further includes the step: Obtaining the maximum height value and the minimum height value of the multiple detection points within the outer contour, and obtaining a height difference according to the maximum height value and the minimum value; Judging whether the installation of the screw is qualified according to the height difference and the preset height difference.

10. The screw floating lock detection method according to any one of claims 1 to 6, characterized in that, The step of judging whether the protruding height of the screw is qualified according to the protruding height and the preset height information includes: If it is qualified, directly enter the next process; If it is unqualified, obtain the two-dimensional code information of the workpiece to be detected and send it to the controller, and the controller controls the gripper to take away the unqualified workpiece to be detected.

11. The screw floating lock detection method according to any one of claims 1 to 6, characterized in that, Before the step of obtaining the image information of the workpiece to be detected by the 3D infrared camera, there is also a step: Receive the in-place detection signal, and turn on the 3D infrared camera according to the in-place detection signal.

12. A screw floating lock detection device, which adopts the screw floating lock detection method described in any one of claims 1 to 11, is characterized in that, It includes: A base, a first driving member, a mounting bracket and a 3D infrared camera. The first driving member is installed on the base, the mounting bracket is connected to the first driving member, the 3D infrared camera is installed on the mounting bracket, and the 3D infrared camera includes a transmitting member and a receiving member. The transmitting member is used to receive the in-place detection signal and emit infrared light to irradiate the workpiece to be detected, and the receiving member is used to receive the light beam reflected by the workpiece to be detected to obtain the image information of the workpiece to be detected.

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