Screw floating lock detection method and equipment

Abstract

The present invention provides a method and device for detecting screw floating locks. The method comprises the following steps: obtaining image information of a component to be inspected using a 3D infrared scanning camera, the component to be inspected comprising a mounting plate and a screw attached to the mounting plate; identifying the outer contour of the screw nut and an exposed area of ​​the mounting plate based on the image information, wherein the exposed area of ​​the mounting plate is an area without a screw; selecting a detection point within the outer contour and obtaining first height information of the detection point; selecting a reference point on the exposed area of ​​the mounting plate and obtaining second height information of the reference point; obtaining a protruding height of the screw based on the first and second height information; and determining whether the protruding height of the screw meets the requirements based on the protruding height and preset height information. This method for detecting screw floating locks 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 in particular to a screw floating lock detection method and equipment. Background Art

[0002] In the manufacturing process of products in the domestic consumer electronics industry, it is difficult to identify whether there is a floating lock phenomenon after the screws are tightened by visual inspection. The current mechanical contact measurement and detection method has 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 efficiency of screw floating lock detection in the related art.

[0005] According to some embodiments of the present invention, the present invention provides a method for detecting screw floating lock, the method comprising:

[0006] Acquiring image information of a to-be-detected part by a 3D infrared scanning camera, wherein the to-be-detected part includes a mounting plate and screws fastened to the mounting plate;

[0007] Identifying an outer contour of the nut of the screw and an exposed area of ​​the mounting plate according to the image information, wherein the exposed area of ​​the mounting plate is an area where no screw is provided;

[0008] Selecting a detection point within the outer contour and obtaining first height information of the detection point, selecting a reference point on the exposed area of ​​the mounting plate and obtaining second height information of the reference point;

[0009] Acquiring a protruding height of the screw according to the first height information and the second height information;

[0010] Whether the protruding height of the screw is qualified is determined according to the protruding height and preset height information.

[0011] In some embodiments, the step of selecting a detection point within the outer contour includes:

[0012] The center point of the nut is obtained according to the outer contour, a straight line is drawn through the center point, and two detection points are selected at positions where the straight line is close to the outer contour; wherein the two detection points are respectively located on both sides of the center point.

[0013] In some embodiments, the step of selecting a detection point within the outer contour includes:

[0014] The center point of the nut is obtained according to the outer contour, and a detection circle is made with the center point as the center. The detection circle is within and close to the outer contour, and multiple detection points are selected on the detection circle. The multiple detection points are evenly distributed on the detection circle.

[0015] In some embodiments, the distance between the detection point and the outer contour is defined as d, then 0 <d≤2mm。

[0016] In some embodiments, the part to be inspected is provided with a plurality of screws, and the step of identifying the outer contours of the nuts of the screws and the exposed area of ​​the mounting plate according to the image information includes:

[0017] The outer contour of the nut of one of the screws is identified based on the image information, the outer contours of the nut of the remaining screws are obtained based on the relative positional relationship between the remaining screws and one of the screws, and the exposed area of ​​the mounting plate is identified.

[0018] In some embodiments, there are multiple reference points, and the step of selecting reference points on the exposed area of ​​the mounting plate includes:

[0019] The corresponding reference point is selected at a position close to the outer contour in the exposed area of ​​the mounting plate.

[0020] In some embodiments, the step of obtaining the first height information of the detection point includes:

[0021] The height values ​​of the detection points within each outer contour are respectively obtained, and the maximum height value is used as the first height information.

[0022] In some embodiments, the step of obtaining the first height information of the detection point includes:

[0023] The height values ​​of the detection points within each outer contour are respectively obtained, an average height value of the detection points is obtained according to the height values, and the average height value is used as the first height information.

[0024] In some embodiments, there are multiple detection points, and after the step of determining whether the protruding height of the screw is qualified according to the protruding height and the preset height information, the step further includes:

[0025] Obtaining a maximum height value and a minimum height value of a plurality of detection points within the outer contour, and obtaining a height difference value according to the maximum height value and the minimum height value;

[0026] Whether the screw installation is qualified is determined based on the height difference and the preset height difference.

[0027] In some embodiments, the step of determining whether the protrusion height of the screw is qualified based on the protrusion height and preset height information includes:

[0028] If qualified, go directly to the next process;

[0029] If it is unqualified, the QR code information of the to-be-tested piece is obtained and sent to the controller, and the controller controls the gripper to take away the unqualified to-be-tested piece.

[0030] In some embodiments, before the step of acquiring image information of the part to be inspected by using a 3D infrared scanning camera, the following steps are further included:

[0031] A position detection signal is received, and the 3D infrared scanning camera is turned on according to the position detection signal.

[0032] According to some embodiments of the present invention, the present invention provides a screw floating lock detection device, which adopts any of the screw floating lock detection methods described above, including: a base, a first driving member, a mounting bracket and a 3D infrared scanning camera, the first driving member is installed on the base, the mounting bracket is connected to the first driving member, the 3D infrared scanning camera is installed on the mounting bracket, the 3D infrared scanning camera includes a transmitting member and a receiving member, the transmitting member is used to receive an in-place detection signal and emit infrared light to illuminate the part to be detected, and the receiving member is used to receive a light beam reflected by the part to be detected to obtain image information of the part to be detected.

[0033] In the above scheme, a 3D infrared scanning camera is used to obtain image information of the part to be inspected, which includes a mounting plate and a screw fastened to the mounting plate. Based on the image information, the outer contour of the screw's nut and the exposed area of ​​the mounting plate are identified, where the exposed area of ​​the mounting plate is the area without screws. A detection point is selected within the outer contour and first height information of the detection point is obtained. A reference point is selected on the exposed area of ​​the mounting plate and second height information of the reference point is obtained. Based on the first and second height information, the screw's protrusion height is determined. Based on the protrusion height and preset height information, the screw's protrusion height is determined to be acceptable. This invention has the advantage of high detection efficiency.

[0034] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are specifically listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. The same reference numerals are used throughout the drawings to denote the same components. In the drawings:

[0036] Figure 1 Schematic diagram of the process of detecting screw floating lock according to the first embodiment of the present invention;

[0037] Figure 2 Schematic diagram of the process of detecting screw floating lock according to the second embodiment of the present invention;

[0038] Figure 3 Schematic diagram of the process of detecting screw floating lock according to the third embodiment of the present invention;

[0039] Figure 4 Schematic diagram of the process of detecting screw floating lock according to the fourth embodiment of the present invention;

[0040] Figure 5 Schematic diagram of the process of detecting screw floating lock according to the fifth embodiment of the present invention;

[0041] Figure 6 Schematic diagram of the process of detecting screw floating lock according to the sixth embodiment of the present invention;

[0042] Figure 7 Schematic diagram of the process of detecting screw floating lock according to the seventh embodiment of the present invention;

[0043] Figure 8 Schematic diagram of the process of detecting screw floating lock according to the eighth embodiment of the present invention;

[0044] Figure 9 A schematic diagram of image information obtained by a screw floating lock detection method according to an embodiment of the present invention;

[0045] Figure 10 This is a structural schematic diagram of a screw floating lock detection device according to an embodiment of the present invention.

[0046] The accompanying drawings in the specific implementation manner are as follows:

[0047] 100. Screw floating lock detection equipment;

[0048] 10. Base; 20. First driving member; 30. Mounting bracket; 40. 3D infrared scanning camera;

[0049] 200, assembly line; 300, part to be inspected; 310, mounting plate; 320, nut;

[0050] A. Check point; B. Reference point. DETAILED DESCRIPTION

[0051] The following embodiments of the technical solution of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention and are therefore only examples and are not intended to limit the scope of protection of the present invention.

[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art 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-mentioned drawings are intended to cover non-exclusive inclusions.

[0053] In the description of the embodiments of the present invention, technical terms such as "first" and "second" are used solely to distinguish between different objects and should not be understood to indicate or imply relative importance or to implicitly specify the quantity, specific order, or primary and secondary relationship of the technical features indicated. In the description of the embodiments of the present invention, "plurality" means more than two, unless otherwise specifically defined.

[0054] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute a separate or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0055] In the description of the embodiments of the present invention, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exists simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0056] In the description of the embodiments of the present invention, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0057] In the description of the embodiments of the present invention, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not 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 cannot be understood as limiting the embodiments of the present invention.

[0058] In the description of the embodiments of the present invention, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and can refer to internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on specific circumstances.

[0059] Floating lock is a common problem in the screw locking process. Whether using an ordinary air screwdriver or an automatic screw locking machine, you may encounter a situation where the torque reaches the preset target, but the screw is still not locked in place. This situation is usually called floating lock, floating height or floating nail. Floating lock means that the screw is not locked in place. It may be that the nut height of the screw is too high, or the nut is installed at an angle due to the tilt of the screw installation. In the related art, mechanical measurement methods are generally used to measure the height of the nut relative to the mounting plate using a vernier caliper. This manual detection method has low detection efficiency.

[0060] To this end, the applicant provides a screw floating lock detection method.

[0061] Reference Figure 1 , Figure 1 FIG. 5 is a flow chart of a screw floating lock detection method according to a first embodiment of the present invention. The screw floating lock detection method includes:

[0062] S100, acquiring image information of a to-be-inspected part 300 by a 3D infrared scanning camera 40, wherein the to-be-inspected part 300 includes a mounting plate 310 and screws fastened to the mounting plate 310;

[0063] The part to be inspected 300 here includes a mounting plate 310 locked to the screws on the mounting plate 310. The mounting plate 310 can be a printed circuit board or a substrate. A plurality of components can be arranged on the mounting plate 310. The screw includes a nut 320 and a screw rod. The screw rod is generally locked in the mounting plate 310, and the nut 320 is exposed on the mounting plate 310. The purpose of this application is to determine whether the screw locking is qualified by measuring the height of the nut 320 exposed or extending out of the mounting plate 310, that is, whether there is a floating lock phenomenon. Unqualified situations include the screw being too loose and the screw being misaligned, causing the nut 320 to tilt to one side. The 3D infrared scanning camera 40 can obtain image information of the part to be inspected 300. The image information here can include a 3D image, which can display the height characteristics of the nut 320. The 3D infrared scanning camera 40 can also convert the 3D features into 2.5D graphics during the scanning process, which can facilitate the positioning and guidance calculation of the screw position.

[0064] S200, identifying the outer contour of the screw nut 320 and the exposed area of ​​the mounting plate based on the image information, wherein the exposed area of ​​the mounting plate is an area where no screw is provided;

[0065] It should be noted that when mounting plate 310 is only equipped with screws, the exposed area of ​​the mounting plate refers to the area without screws. For mounting plate 310 equipped with other components, the exposed area also refers to the area without screws and other components. Based on the captured image information and the known outer contour of nut 320, the controller can determine the location of the outer contour of nut 320. If the remaining area is a plate-like object, it can be identified as the exposed area of ​​the mounting plate.

[0066] S300, selecting a detection point A within the outer contour and obtaining first height information of the detection point A, selecting a reference point B on the exposed area of ​​the mounting plate and obtaining second height information of the reference point B;

[0067] Combined with reference Figure 9 , Figure 9The diagram shows a circular outer contour with two selected detection points A. It should be noted that the actual image captured will also reflect height features. The points within the outer contour are points on the nut 320, and are located on the side of the nut 320 facing away from the screw, or in other words, on the side of the nut 320 facing away from the mounting plate 310. Selecting a point within the outer contour means selecting a point on the nut 320 as the detection point A. Because a 3D infrared scanning camera 40 is used, first height information for detection point A can be obtained. This first height information includes the height coordinates of detection point A. A reference point B is selected in an exposed area of ​​the mounting plate. The second height information for reference point B includes the height coordinates of reference point B. The screw is attached to the mounting plate 310, and reference point B is used as a reference to facilitate determining the protrusion height of the nut 320 relative to the mounting plate 310 in subsequent steps. It should be noted that one or more detection points A within the outer contour of a nut 320 can be selected, and those skilled in the art can set these based on actual needs.

[0068] S400, obtaining a protruding height of the screw according to the first height information and the second height information;

[0069] This application uses the protruding height of the nut 320 to determine whether the screw has a floating lock phenomenon. The protruding height of the nut 320 in this application and the protruding height of the screw have the same meaning. Floating lock may include the screw not being locked tightly, resulting in the protruding height of the nut 320 being too large; or the screw being locked with an inclination, resulting in the protruding height of the nut 320 being large at some positions and small at some positions. Of course, unqualified situations also include the screw being locked too tightly, resulting in the protruding height being too small, which can also be detected in this application. It should be noted that the protruding height of the screw is the top surface of the nut 320, that is, the height of 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. The protruding height of the screw can be obtained by subtracting the heights of the two.

[0070] S500: Determine whether the protruding height of the screw is qualified based on the protruding height and the preset height information.

[0071] After acquiring image information, the 3D infrared scanning camera 40 can transmit it to the controller, which can calculate the protrusion height. A qualified protrusion height range, referred to herein as preset height information, can be preset within the controller. If the protrusion height range is within the preset height information range, the screw is determined to be properly secured, with no floating lock. If the protrusion height range is outside the preset height information range, the screw is determined to be unsatisfactory, with floating lock present.

[0072] In the above-described embodiment of the present invention, image information of the part to be inspected 300 is acquired by a 3D infrared scanning camera 40. The outer contour of the screw nut 320 and the exposed area of ​​the mounting plate are identified based on the image information. Inspection point A is selected within the outer contour, and first height information of inspection point A is acquired. Reference point B is selected on the exposed area of ​​the mounting plate, and second height information of reference point B is acquired. The protruding height of the screw is acquired based on the first and second height information, and whether the protruding height of the screw is qualified is determined based on the protruding height and the preset height information. This embodiment acquires image information through a 3D infrared scanning camera 40 and transmits it to a controller. Based on the image information, the controller is able to acquire the protruding height of the nut 320 and determine whether the screw has a floating lock phenomenon. Automatic detection is employed for high detection efficiency.

[0073] Reference Figure 2 , Figure 2 This is a flow chart of a screw floating lock detection method according to a second embodiment of the present invention. The step of selecting a detection point A within the outer contour includes:

[0074] 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 where the straight line is close to the outer contour; wherein the two detection points A are located on both sides of the center point.

[0075] The shape of the outer contour is 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. Figure 9 For example, if the outer contour is a circle, the center point is the center of the circle. A straight line is drawn through the center point, intersecting the two opposite sides of the outer contour. For example, if the center point is the center of the circle, the straight line can be a diameter. Two detection points A are selected at either end of the diameter, close to the outer contour, with the two points located on either side of the center point. This embodiment is particularly suitable for detecting tilt in the nut 320. When there is a floating lock, the heights of the various points on the nut are not completely consistent. Because the nut 320 is tilted, one side is higher and the other side is lower. If only one point is detected, if the lower point is selected, there may be a misjudgment that the screw does not have a floating lock. Therefore, the two points are selected on either side of the center point. The position close to the outer contour is selected because the position of the outer contour relative to the center point is generally the highest or lowest point of the tilt, which makes the detection result more accurate. In addition, selecting two detection points A can reduce the controller's computational workload or image processing time, greatly improving detection efficiency. It should be noted that this application is particularly suitable for detecting flat-head screws, but of course, it can also be applied to the detection of convex nuts 320.

[0076] In the above embodiment of the present invention, two opposite points close to the outer contour are selected as detection points A. The selected detection points A are more representative and can improve detection accuracy.

[0077] Reference Figure 3 , Figure 3 This is a flow chart of a screw floating lock detection method according to a third embodiment of the present invention. The step of selecting a detection point A within the outer contour includes:

[0078] 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, the detection circle is inside and close to the outer contour, select multiple detection points A on the detection circle, and the multiple detection points A are evenly distributed on the detection circle.

[0079] This embodiment adopts an embodiment of selecting three or more detection points A within the outer contour. The shape of the outer contour, that is, the shape of the outer circumference of the nut 320, 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. For example, when the outer contour is a circle, the center point is the center of the circle. With the center point as the center of the circle, a number smaller than the radius of the outer contour is selected as the radius to make a detection circle. Generally, if the nut 320 is tilted, one side will be higher and the other side will be lower. When only one point is detected, if the lower point is selected, there may be a misjudgment that the screw does not have a floating lock phenomenon. In addition, the highest and lowest points of the tilt are generally located on the outer contour, so the detection circle is set as close to the outer contour as possible to improve the accuracy of the detection. At the same time, in order to ensure that the selected points can cover all positions of the nut 320 as much as possible, multiple detection points A can be set to be evenly distributed on the detection circle with equal intervals.

[0080] In the above embodiment of the present invention, multiple detection points A are selected on the detection circle and evenly distributed on the detection circle, so that the detection points A can cover all positions of the nut 320 as much as possible, thereby improving the detection accuracy.

[0081] In some embodiments, the distance between the detection point A and the outer contour is defined as d, then 0 <d≤2mm。

[0082] The distance between the detection point A and the outer contour can be thought of as the distance from a point to a circle, meaning the distance from each detection point A to the closest outer contour. As previously described, this distance can be set as small as possible, placing the selected detection point A closer to the outer contour. This allows detection of not only improperly tightened screws but also tilted screws.

[0083] Reference Figure 4 , Figure 4This is a flow chart of a screw floating lock detection method according to a fourth embodiment of the present invention. A plurality of screws are provided on a component to be detected 300. Step S200 includes:

[0084] S201, identifying the outer contour of the nut 320 of one of the screws based on the image information, obtaining the outer contours of the nuts 320 of the remaining screws based on the relative positional relationship between the remaining screws and one of the screws, and identifying the exposed area of ​​the mounting plate.

[0085] It should be noted that in the actual detection process, when there are multiple screws, the outer contours of multiple screws can be identified at the same time based on the image recognition information, so that the heights of multiple screws can be detected at the same time. Compared with laser detection, laser detection requires scanning and detecting the nuts 320 one by one, and the technical solution of this application can pick up the image information of multiple screws at the same time, and detect multiple nuts 320 at the same time, which significantly improves the detection efficiency. However, there is also a problem. Figure 9 As shown, due to problems such as the lighting angle or the reflection intensity, the outer contour of some nuts 320 may have dark lines or dark spots, such as Figure 9 As shown in C in the figure, the outer contour of the nut 320 is unclear. Those skilled in the art will appreciate that the installation positions of the screws on the mounting plate 310 can be pre-set, meaning the relative positional relationships of the screws are fixed. Therefore, the present application can capture a clear outer contour image of the nut 320 from the image information. Based on this clear outer contour image of the nut 320, the center point of the outer contour can be obtained. From the coordinates of this center point and the pre-set relative positional relationships of the screws, the positional coordinates of the remaining screws, i.e., the center point coordinates of the remaining nuts 320, can be used to determine the outer contour of the nut 320. Furthermore, the outer contour of the nut 320 can be determined based on the size of the nut 320. Of course, the outer contours of the remaining nuts 320 can also be directly determined based on the outer contour of one nut 320 and its relative positional relationship. This method of obtaining the outer contour of the nut 320 using relative positional relationships is calculated rather than acquired through image capture (except for the first one). Furthermore, the first outer contour can be selected from the clearest of the multiple screw outer contours, reducing the risk of unclear outer contours of the nut 320 and difficulty in accurate identification due to lighting angles or reflections, further improving detection accuracy.

[0086] In the above-mentioned embodiment of the present invention, the outer contour of the nut 320 of one of the screws is identified by image information, and the outer contours of the nuts 320 of the remaining screws are obtained based on the relative position relationship between the remaining screws and one of the screws. This can improve the detection accuracy and reduce the impact of unclear outer contours on the detection results due to light intensity or reflected light.

[0087] In some embodiments, there are multiple reference points B, and the step of selecting reference points B on the exposed area of ​​the mounting plate includes:

[0088] Select the corresponding reference point B near the outer contour of the exposed area of ​​the mounting plate.

[0089] In the case where the mounting plate 310 is a flat plate, it is generally sufficient to select a single reference point B. However, due to the installation of components, the mounting plate 310 may be partially warped. If all nuts 320 are calculated based on the same reference point B, the test results may be inaccurate, because we generally use the surface of the adjacent mounting plate 310 as a reference to determine whether the screw is floating. In particular, the mounting plate 310 can also be shaped like a trapezoidal plate, that is, there are two or more different heights. In this case, different reference points B must be selected for detecting whether the screw is floating. Generally speaking, the principle for selecting reference point B is to select it on the corresponding installation surface of the screw.

[0090] In the above embodiment of the present invention, by selecting a corresponding reference point B at a position close to the outer contour of the exposed area of ​​the mounting plate, it is ensured that the reference point B is selected on the mounting surface of the corresponding screw, thereby ensuring measurement accuracy.

[0091] Reference Figure 5 , Figure 5 This is a flow chart of a screw floating lock detection method according to a fifth embodiment of the present invention, wherein the steps of obtaining the first height information of the detection point A include:

[0092] S310 , respectively obtaining the height value of each detection point A within each outer contour, and taking the maximum height value as the first height information of the corresponding outer contour.

[0093] When there are multiple screws, each screw is tested separately and then compared individually. Within the outer contour of a nut 320, the height value of each detection point A is obtained, and the one with the largest height value is used as the first height information. The outer contours of other nuts 320 are calculated in the same way. Each outer contour corresponds to a maximum height value, and then the maximum height value of each outer contour is subtracted from the second height information to obtain the protruding height, and each screw is judged to be qualified for installation. If the maximum height value meets the requirements, it proves that the screw is not under-tightened. This embodiment selects the maximum height value within the outer contour for calculation, and the calculation process is simple, which is conducive to improving detection efficiency.

[0094] Reference Figure 6 , Figure 6 This is a flow chart of a screw floating lock detection method according to a sixth embodiment of the present invention, wherein the steps of obtaining the first height information of the detection point A include:

[0095] S320 , respectively obtaining the height value of each detection point A within each outer contour, obtaining an average height value of the detection points A based on each height value, and using the average height value as the first height information.

[0096] Sometimes, when the screw installation angle is small, we are concerned about whether the average height of each position meets the requirements. If the screw installation angle is small and the average height of each point meets the requirements, it can be assumed that most of the positions of the nut are within the preset range and are acceptable. Therefore, the height values ​​of each detection point A within each outer contour can be obtained, and the average value within each outer contour is taken to obtain the average height value. This average height value is used as the first height information and compared with the height of the reference point B to determine whether the protrusion height is qualified.

[0097] By respectively obtaining the height value of each detection point A within each outer contour, obtaining the average height value of the detection point A based on each height value, and using 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.

[0098] Reference Figure 7 , Figure 7 This is a flow chart of a method for detecting screw floating lock according to a seventh embodiment of the present invention. There are multiple detection points A. After step S500, the following steps are further included:

[0099] S600, obtaining a maximum height value and a minimum height value of a plurality of detection points A within the outer contour, and obtaining a height difference value according to the maximum height value and the minimum height value;

[0100] This embodiment is particularly suitable for judging whether the screw is installed at an angle. Specifically, if the screw is installed at an angle, that is, the nut 320 is tilted, then the minimum height value and the maximum height value will exist on opposite sides, and the more the screw is tilted, the greater the difference between the maximum height value and the minimum height value. At the same time, the greater the inclination of the screw, the floating lock phenomenon that the screw is not installed in place. Taking two selected points and a circular outer contour as an example, the two selected points are respectively located at positions where the diameter is close to the outer contour and are located on both sides of the center of the circle. At this time, the height difference of the nut 320 can be judged by the maximum height value and the minimum height value. The height difference reflects the degree of inclination of the nut 320. If the degree of inclination is serious, it means that the screw is floating locked.

[0101] S700: Determine whether the screw installation is qualified based on the height difference and a preset height difference.

[0102] If the height difference is within the preset height difference range, it is judged as qualified; otherwise, it is judged as unqualified.

[0103] In the above embodiment of the present invention, by obtaining the maximum height value and the minimum height value of the multiple detection points A within the outer contour, the height difference value is obtained according to the maximum height value and the minimum value to determine whether the screw installation is qualified. This embodiment is particularly suitable for determining whether the inclination degree of the nut 320 exceeds the preset limit.

[0104] In some embodiments, the steps of S500 include:

[0105] If qualified, go directly to the next process;

[0106] If the product is qualified, it will directly enter the next production process.

[0107] If the test result is unqualified, the QR code information of the test piece 300 is obtained and sent to the controller, which controls the gripper to remove the unqualified test piece 300. Specifically, in this step, if the test result is unqualified, the QR code information of the test piece 300 can be obtained by an image recognition device such as a radio frequency identification device and sent to the controller. The controller can identify the corresponding unqualified part based on the QR 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 identify the QR code information of each test piece 300 to facilitate traceability.

[0108] In the above embodiment of the present invention, by acquiring the QR code information of the part to be inspected 300 and sending it to the controller, the controller controls the gripper to take away the unqualified part to be inspected 300, so that the unqualified parts can be removed in time.

[0109] Reference Figure 8 , Figure 8 This is a flowchart of a screw floating lock detection method according to an eighth embodiment of the present invention. Before step S100, the following steps are also included:

[0110] S010: receiving an in-position detection signal, and turning on the 3D infrared scanning camera 40 according to the in-position detection signal.

[0111] The in-position detection signal here refers to when the inspected part 300 moves to a predetermined position and strikes a magnetic induction switch on the assembly line 200. The magnetic induction switch transmits an in-position detection signal, which is received by the controller. Detection of the in-position detection signal indicates that the inspected part 300 has moved to the inspection position, and the 3D infrared scanning camera 40 can be automatically activated to begin inspection.

[0112] By setting the 3D infrared scanning camera 40 to be turned on according to the in-position detection signal, automatic start of detection can be achieved.

[0113] Reference Figure 10According to some embodiments of the present invention, a screw floating lock detection device 100 is provided, which adopts any of the screw floating lock detection methods described above, and includes: a base 10, a first driving member 20, a mounting frame 30, and a 3D infrared scanning 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 scanning camera 40 is mounted on the mounting frame 30. The 3D infrared scanning camera 40 includes a transmitter and a receiver. The transmitter is used to receive an in-position detection signal and emit infrared light to illuminate the part to be inspected 300, and the receiver is used to receive a light beam reflected by the part to be inspected 300 to obtain image information of the part to be inspected 300. The screw floating lock detection device 100 is installed next to an assembly line 200. A tooling is provided on the assembly line 200. The part to be inspected 300 is placed on the tooling, and the tooling moves on the assembly line 200. The assembly line 200 is provided with a magnetic induction switch. When the tooling moves to the detection position, it can trigger the magnetic induction switch to send an in-position detection signal to the controller, and the controller controls the 3D infrared scanning camera 40 to be turned on. The 3D infrared scanning camera 40 emits infrared light to illuminate the part to be detected 300, and the receiving part is used to receive the light beam reflected by the part to be detected 300 to obtain image information of the part to be detected 300. The first driving member 20 is used to control the height of the 3D infrared scanning camera 40 in the vertical or horizontal direction. Of course, a second driving member and a third driving member can also be provided to adjust the position of the 3D infrared scanning camera 40 in the other two directions of three-dimensional space. A long strip hole can also be provided on the mounting frame 30 to fine-tune the height of the 3D infrared scanning camera 40. The stroke can be selected according to the volume and position requirements of different products. The position can be adjusted by setting the open touch screen in the electronic control system to achieve precise positioning of 0.001mm, realizing full coverage of automatic scanning and detection of products. The basic working process of the screw floating lock detection equipment 100 is as follows: when the part to be detected 300 flows to the detection position, the magnetic induction switch is triggered, and the magnetic induction switch sends an in-place detection signal to the controller. The in-place detection signal is fed back to the controller to trigger the 3D infrared scanning camera 40 to perform screw height detection. The detection data is uploaded to the host computer for result judgment and data storage. The product with an OK result flows to the next process, and the single cycle of work is completed.

[0114] 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 aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A screw floating lock detection method, characterized in that: The screw floating lock detection method comprises: Acquiring image information of a to-be-detected part by a 3D infrared scanning camera, wherein the to-be-detected part includes a mounting plate and a plurality of screws fastened to the mounting plate; Identifying an outer contour of a nut cap of one of the screws based on the image information, obtaining outer contours of the nut caps of the remaining screws based on relative positional relationships between the remaining screws and the one of the screws, and identifying an exposed area of ​​the mounting plate, wherein the outer contour of the nut cap of the one of the screws selected is an outer contour with a clear image among the multiple screws, and the exposed area of ​​the mounting plate is an area where no screws are provided; Selecting a detection point within the outer contour and obtaining first height information of the detection point, selecting a reference point on the exposed area of ​​the mounting plate and obtaining second height information of the reference point; Acquiring a protruding height of the screw according to the first height information and the second height information; Whether the protruding height of the screw is qualified is determined according to the protruding height and preset height information.

2. The screw floating lock detection method according to claim 1, characterized in that: The step of selecting detection points within the outer contour comprises: The center point of the nut is obtained according to the outer contour, a straight line is drawn through the center point, and two detection points are selected at positions where the straight line is close to the outer contour; wherein 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, characterized in that: The step of selecting detection points within the outer contour comprises: The center point of the nut is obtained according to the outer contour, and a detection circle is made with the center point as the center. The detection circle is set within and close to the outer contour, and multiple detection points are selected on the detection circle, and the multiple detection points are evenly distributed on the detection circle.

4. The screw floating lock detection method according to claim 1, characterized in that: Define the distance between the detection point and the outer contour as d, then 0 <d≤2mm。 5. The screw floating lock detection method according to claim 1, characterized in that: There are multiple reference points, and the step of selecting reference points on the exposed area of ​​the mounting plate includes: The corresponding reference point is selected at a position close to the outer contour in the exposed area of ​​the mounting plate.

6. The screw floating lock detection method according to any one of claims 2 to 5, characterized in that: There are multiple detection points, and the step of obtaining first height information of the detection points includes: The height values ​​of the detection points within the outer contours are respectively obtained, and the maximum height value is used as the first height information.

7. The screw floating lock detection method according to any one of claims 2 to 5, characterized in that: There are multiple detection points, and the step of obtaining first height information of the detection points includes: The height values ​​of the detection points within the outer contours are respectively obtained, and an average height value of the detection points is obtained according to the height values, and the average height value is used as the first height information.

8. The screw floating lock detection method according to any one of claims 1 to 5, characterized in that: There are multiple detection points, and 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 step further includes: Acquire a maximum height value and a minimum height value of a plurality of the detection points within the outer contour, and obtain a height difference value according to the maximum height value and the minimum height value; Whether the screw installation is qualified is determined based on the height difference and the preset height difference.

9. The screw floating lock detection method according to any one of claims 1 to 5, 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 qualified, go directly to the next process; If it is unqualified, the QR code information of the to-be-tested piece is obtained and sent to the controller, and the controller controls the gripper to take away the unqualified to-be-tested piece.

10. The screw floating lock detection method according to any one of claims 1 to 5, characterized in that: Before the step of obtaining image information of the part to be inspected by using a 3D infrared scanning camera, the following steps are also included: A position detection signal is received, and the 3D infrared scanning camera is turned on according to the position detection signal.

11. A screw floating lock detection device, using the screw floating lock detection method according to any one of claims 1 to 10, characterized in that: include: A base, a first driving member, a mounting bracket and a 3D infrared scanning camera, wherein the first driving member is mounted on the base, the mounting bracket is connected to the first driving member, and the 3D infrared scanning camera is mounted on the mounting bracket. The 3D infrared scanning camera includes a transmitter and a receiver, wherein the transmitter is used to receive an in-place detection signal and emit infrared light to illuminate the part to be detected, and the receiver is used to receive a light beam reflected by the part to be detected to obtain image information of the part to be detected.

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