PCB pin recognition adjustment device and control method thereof

Abstract

The application discloses a PCB pin recognition and adjustment device, which comprises a main support frame (1), wherein the upper end of the main support frame (1) is provided with a top support frame (2), the top support frame (2) is provided with a CCD camera (3), the front side of the main support frame (1) is provided with a three-axis moving mechanism (4), the moving end of the three-axis moving mechanism (4) is provided with a pin clamping and adjusting assembly (5), and the pin clamping and adjusting assembly (5) comprises a seat body (6), and the two ends of the seat body (6) are respectively provided with a rotating motor (7) and a swing motor (8). The application can be used for the positioning correction of multiple curved pins, and the pin correction effect is improved.

Description

Technical Field

[0001] This invention relates to the field of PCB board inspection equipment, and in particular to a PCB board pin identification and adjustment device and its control method. Background Technology

[0002] During the installation of an electric power steering system, the condition of the PCB board pins is crucial. Pins may be broken, missing, or bent during manufacturing. Therefore, it is necessary to inspect the PCB board pins. If a pin is bent, it needs to be corrected. For example, Chinese invention patent CN114650726B discloses a multi-pin automatic correction insertion mechanism, which corrects the position of pins during PIN insertion on the PCB, ensuring accurate insertion into vias. It includes a first clamping plate, a second clamping plate, and a drive assembly. The first and second clamping plates constrain the pins to the correct position, and the drive assembly moves the first and second clamping plates along a preset trajectory. During the movement of the first and second clamping plates, this type of pin straightening mechanism straightens the pins within the space formed by the first and second clamping plates and the first and second clamping pieces. This straightening mechanism straightens multiple pins simultaneously, which may result in a less than ideal straightening effect, and some pins may not be straightened properly. Summary of the Invention

[0003] The purpose of this invention is to provide a PCB board pin identification and adjustment device and its control method. This invention can perform individual positioning and correction of multiple bent pins, improving the pin correction effect.

[0004] The technical solution of the present invention: a PCB board pin identification and adjustment device, including a main support frame, characterized in that: a top bracket is provided at the upper end of the main support frame, a CCD camera is provided on the top bracket, a three-axis moving mechanism is provided on the front side of the main support frame, a pin clamping and adjusting assembly is provided on the moving end of the three-axis moving mechanism, the pin clamping and adjusting assembly includes a base, a rotary motor and a swing motor are respectively provided at both ends of the base, a gear frame is provided on the extended end of the swing motor, a rotating shaft is connected to the extended end of the rotary motor, the gear frame is connected to the rotating shaft via a bearing, a driving gear is provided on the rotating shaft, a driven gear is provided on the gear frame via a shaft, an extension plate is provided at one end of the shaft, a pneumatic gripper is provided under the extension plate, a sleeve cylinder is provided on one side of the extension plate, and a straightening sleeve is provided at the extended end of the sleeve cylinder.

[0005] In the aforementioned PCB board pin identification and adjustment device, the inner side of the pneumatic gripper is provided with multiple support blocks.

[0006] In the aforementioned PCB board pin identification and adjustment device, the inner side of the correction sleeve has a horn-shaped structure.

[0007] The specific steps in the aforementioned PCB board pin identification and adjustment device are as follows: S1: First, start the CCD camera to acquire images of the pin area of ​​the PCB board, and preprocess the acquired images; S2: Check the pin alignment to see if the pin is qualified. If qualified, the process ends. If not qualified, determine if the pin is crossed or missing. S3: If the pin is crossed or missing, an audible and visual alarm will be triggered, and the pin will be manually processed. If the pin is only bent, the bent pin will be located and the bending curvature of the pin will be checked to see if it exceeds the correction threshold. S4: If the bending curvature of the pin exceeds the correction threshold, an audible and visual alarm will be triggered and manual intervention will be required. If the bending curvature does not exceed the correction threshold, the three-axis moving mechanism will drive the pin clamping and adjusting component to the problematic pin for correction. The straightened pin will then need to be re-tested for alignment.

[0008] In the aforementioned PCB board pin identification and adjustment control method, in step 1, the preprocessing includes image enhancement, image smoothing and denoising, image grayscale conversion, and image thresholding segmentation.

[0009] In the aforementioned PCB board pin identification and adjustment control method, in step 1, the CCD camera, in conjunction with light illumination, obtains the point coordinates of the pin, calculates the distance between the plane containing the pin's point coordinates and the reference plane, and thus determines whether the pin has a broken pin.

[0010] In the aforementioned PCB board pin identification and adjustment control method, in step 4, the three-axis moving mechanism positions the pneumatic gripper of the pin clamping assembly above the bent pin. The rotary motor drives the pneumatic gripper to be on the same plane as the bending direction of the pin. The swing motor drives the pneumatic gripper to swing and move by an angle, and the opening of the pneumatic gripper is aligned with the bent pin. The Z-axis motor of the three-axis moving mechanism starts, and the pneumatic gripper wraps around the bent pin. Then the pneumatic gripper closes, and in conjunction with the three-axis moving mechanism, the pin is corrected. After that, the mechanism resets and a second correction is performed.

[0011] In the aforementioned PCB board pin identification and adjustment control method, the secondary correction is based on the relative distance between the pneumatic gripper and the correction sleeve. The control strategy is adjusted, with the correction sleeve as the working end. The sleeve cylinder drives the correction sleeve to extend downwards, and the three-axis moving mechanism positions the correction sleeve above the pin that was corrected in the first correction. The pin enters the correction sleeve to complete the secondary correction.

[0012] Compared with the prior art, the present invention has the following advantages: 1. In this invention, the three-axis moving mechanism positions the pneumatic gripper of the pin clamping assembly above the bent pin. The rotary motor drives the pneumatic gripper to be in the same plane as the bending direction of the pin. The swing motor drives the pneumatic gripper to swing and move by an angle, and the opening of the pneumatic gripper is aligned with the bent pin. The Z-axis motor of the three-axis moving mechanism starts, and the pneumatic gripper wraps around the bent pin. Then the pneumatic gripper closes. With the help of the three-axis moving mechanism, the pin is corrected. After that, the mechanism resets and a second correction is performed through the correction sleeve. By positioning and correcting a single pin, the pertinence of the correction is improved. The second correction can make the pin more aligned and effectively improve the correction quality.

[0013] 2. The inner side of the pneumatic gripper has multiple support blocks. Since the pins are relatively long and narrow, a surface contact gripper cannot effectively correct the pins. Using a point contact method allows the bent pins to be better stressed, preventing deformation of the middle part of the bent pin's arc and providing better protection.

[0014] 3. A correction sleeve with a flared inner structure is used. When the pin enters the correction sleeve, this shape structure can provide good guidance, help the pin return to the correct position, and achieve pin position correction. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 Schematic diagram of the pin clamping and adjustment assembly; Figure 3 This is a schematic diagram of the support block; Figure 4 This is a schematic diagram of a straightening sleeve; Figure 5 This is a control flowchart of the present invention; Figure 6 A schematic diagram of the point cloud of the pin tip plane; Figure 7 This is a simplified schematic diagram of a pneumatic gripper holding a device.

[0016] The markings in the attached diagram are as follows: 1-Main support frame, 2-Top bracket, 3-CCD camera, 4-Three-axis moving mechanism, 5-Pin clamping and adjusting assembly, 6-Base, 7-Rotary motor, 8-Oscillating motor, 9-Gear frame, 10-Rotating shaft, 11-Driving gear, 12-Driven gear, 13-Extension plate, 14-Pneumatic gripper, 15-Correcting sleeve, 16-Support block, 17-Sleeve cylinder. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0018] Example: PCB board pin identification and adjustment device, including main support frame 1, as shown in the attached figure. Figure 1 As shown, the main support frame 1 has a top bracket 2 at its upper end, and a CCD camera 3 is mounted on the top bracket 2. A three-axis moving mechanism 4 is located on the front side of the main support frame 1, and a pin clamping and adjusting assembly 5 is located on the moving end of the three-axis moving mechanism 4, as shown in the attached diagram. Figure 2 As shown, the pin clamping adjustment assembly 5 includes a base 6, with a rotary motor 7 and a swing motor 8 respectively at both ends of the base 6. A gear frame 9 is provided on the extended end of the swing motor 8, and a rotating shaft 10 is connected to the extended end of the rotary motor 7. The gear frame 9 is connected to the rotating shaft 10 via bearings. A driving gear 11 is provided on the rotating shaft 10, and a driven gear 12 is provided on the gear frame 9 via a shaft. An extension plate 13 is provided at one end of the shaft, and a pneumatic gripper 14 is provided below the extension plate 13. When the rotary motor is running, the gear frame locks, allowing the rotary motor to stably rotate the pneumatic gripper through gear transmission. Multiple support blocks 16 are provided on the inner side of the pneumatic gripper 14, as shown in the attached figure. Figure 3 As shown, due to the relatively long and narrow pins, surface-contact grippers cannot effectively straighten them. Point-contact grippers allow for better force distribution on the bent pins, preventing deformation in the middle of the curved section and providing better protection. A sleeve cylinder 17 is located on one side of the extension plate 13, and a straightening sleeve 15 is located at the extended end of the sleeve cylinder 17. The inner side of the straightening sleeve 15 has a flared structure, as shown in the attached diagram. Figure 4 As shown, a correction sleeve with a flared inner structure is used. When the pin enters the correction sleeve, this shape structure can provide good guidance, help the pin return to the correct position, and achieve pin position correction.

[0019] The control method for implementing the PCB board pin identification and adjustment device is detailed in the attached figure. Figure 5 As shown, the specific steps are as follows: S1: First, start the CCD camera to acquire images of the pin area of ​​the PCB board, and preprocess the acquired images; S2: Check the pin alignment to see if the pin is qualified. If qualified, the process ends. If not qualified, determine if the pin is crossed or missing. S3: If the pin is crossed or missing, an audible and visual alarm will be triggered, and the pin will be manually processed. If the pin is only bent, the bent pin will be located and the bending curvature of the pin will be checked to see if it exceeds the correction threshold. S4: If the bending curvature of the pin exceeds the correction threshold, an audible and visual alarm will be triggered and manual intervention will be required. If the bending curvature does not exceed the correction threshold, the three-axis moving mechanism will drive the pin clamping and adjusting component to the problematic pin for correction. The straightened pin will then need to be re-tested for alignment.

[0020] In step 1, the preprocessing includes image enhancement, image smoothing and denoising, image grayscale conversion, and image thresholding. Under uneven lighting conditions, if the light intensity is high, the grayscale values ​​of the acquired image are mainly distributed in the high grayscale value region; if the light intensity is low, the grayscale values ​​of the acquired image are mainly distributed in the low grayscale value region. This directly affects the quality of image processing. A Gamma correction method is used to non-linearly correct the grayscale of the image, thereby improving image quality.

[0021] In step 1, the CCD camera, in conjunction with light illumination, obtains the point coordinates of the pin. The establishment of the pin's three coordinate points is based on a pin tip 3D reconstruction method using edge detection. First, the Canny operator is used to perform edge detection on the left and right images, segmenting the pin from the image background. Then, based on the obtained edge-detected images, Blob analysis is performed to extract the pin tip contour region from the background. Next, the pin tip planar contour is fitted into a rectangle with directional features, and corner points are extracted from each rectangle to obtain the centroid of the pin tip plane, thus obtaining the pin's planar point cloud, as shown in the attached figure. Figure 6 As shown, the three-dimensional coordinates of the pin tip are calculated based on this point. The distance between the plane where the pin point coordinates are located and the reference plane is calculated, thereby determining whether the pin is broken. The pin position accuracy reaches ±0.2mm.

[0022] In step 4, the three-axis moving mechanism positions the pneumatic gripper of the pin clamping assembly above the bent pin. The rotary motor drives the pneumatic gripper to be in the same plane as the bending direction of the pin, as shown in the attached figure. Figure 7As shown, the swing motor drives the pneumatic gripper to swing and move an angle, with the opening of the pneumatic gripper aligned with the bent pin. The Z-axis motor of the three-axis moving mechanism starts, and the pneumatic gripper wraps around the bent pin. Immediately afterwards, the pneumatic gripper closes, and the X-axis motor or Y-axis motor in the three-axis moving mechanism starts, cooperating with the pneumatic gripper to correct the pin. Afterward, the mechanism resets and performs a second correction. The second correction is based on the relative distance between the pneumatic gripper and the correction sleeve. The control strategy is adjusted, with the correction sleeve as the working end. The sleeve cylinder drives the correction sleeve to extend downward. The three-axis moving mechanism positions the correction sleeve above the pin corrected in the first correction, and the pin enters the correction sleeve to complete the second correction. To simplify the structure, the pneumatic gripper and straightening sleeve are combined on a three-axis moving mechanism controlled by a PLC. When the PLC receives a pre-correction signal, it switches to pre-correction mode, receives the correction position and bending information, calculates and sends motion signals to the X, Y, and Z motors, the rotation and swing motors, and the extension mechanism based on the gripper's position, and performs pre-correction. When the PLC receives a pre-correction signal, it switches to pre-correction mode, receives the correction position information, calculates and sends motion signals to the X, Y, and Z motors based on the sleeve's position, and performs secondary correction. During correction, the rotation speed of the swing motor works in coordination with either the X-axis or Y-axis motor to ensure effective correction of the pins.

[0023] The working principle of this invention is as follows: The three-axis moving mechanism positions the pneumatic gripper of the pin clamping assembly above the bent pin. The rotary motor drives the pneumatic gripper to be in the same plane as the bending direction of the pin. The swing motor drives the pneumatic gripper to swing and move by an angle, and the opening of the pneumatic gripper is aligned with the bent pin. The Z-axis motor of the three-axis moving mechanism starts, and the pneumatic gripper wraps around the bent pin. Then the pneumatic gripper closes, and the pin is corrected in conjunction with the three-axis moving mechanism. After that, the mechanism resets, and a second correction is performed through the correction sleeve. By positioning and correcting a single pin, the pertinence of the correction is improved. The second correction can make the pin more aligned, effectively improving the correction quality.

[0024] The above embodiments merely illustrate implementation methods of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. Furthermore, in these embodiments, "up," "down," "left," "right," "front," and "back" represent relative positions only, not absolute positions. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A PCB board pin identification and adjustment device, comprising a main support frame (1), characterized in that: The main support frame (1) is provided with a top bracket (2) at the upper end, and a CCD camera (3) is provided on the top bracket (2). A three-axis moving mechanism (4) is provided on the front side of the main support frame (1). A pin clamping adjustment component (5) is provided on the moving end of the three-axis moving mechanism (4). The pin clamping adjustment component (5) includes a base (6). A rotary motor (7) and a swing motor (8) are provided at both ends of the base (6). A gear frame (9) is provided on the extended end of the swing motor (8). A rotating shaft (10) is connected to the extended end of the rotary motor (7). The gear frame (9) is connected to the rotating shaft (10) via a bearing. A drive gear (11) is provided on the rotating shaft (10). A driven gear (12) is provided on the gear frame (9) via a shaft. An extension plate (13) is provided at one end of the shaft. A pneumatic gripper (14) is provided under the extension plate (13). A sleeve cylinder (17) is provided on one side of the extension plate (13). A straightening sleeve (15) is provided at the extended end of the sleeve cylinder (17). The control method for implementing the PCB board pin identification and adjustment device comprises the following steps: S1: First, start the CCD camera to acquire images of the pin area of ​​the PCB board, and preprocess the acquired images; S2: Check the pin alignment to see if the pin is qualified. If qualified, the process ends. If not qualified, determine if the pin is crossed or missing. S3: If the pin is crossed or missing, an audible and visual alarm will be triggered, and the pin will be manually processed. If the pin is only bent, the bent pin will be located and the bending curvature of the pin will be checked to see if it exceeds the correction threshold. S4: If the bending curvature of the pin exceeds the correction threshold, an audible and visual alarm will be triggered and manual intervention will be required. If the bending curvature does not exceed the correction threshold, the three-axis moving mechanism will drive the pin clamping and adjusting component to the problematic pin for correction. The straightened pin will then need to be re-tested for alignment. In step 1, the CCD camera, in conjunction with light illumination, obtains the point coordinates of the pin and calculates the distance between the plane containing the pin's point coordinates and the reference plane, thereby determining whether the pin has a broken pin. In step 4, the three-axis moving mechanism positions the pneumatic gripper of the pin clamping assembly above the bent pin. The rotary motor drives the pneumatic gripper to be in the same plane as the bending direction of the pin. The swing motor drives the pneumatic gripper to swing and move by an angle, and the opening of the pneumatic gripper is aligned with the bent pin. The Z-axis motor of the three-axis moving mechanism starts, and the pneumatic gripper wraps around the bent pin. Then the pneumatic gripper closes, and the pin is corrected in conjunction with the three-axis moving mechanism. After that, the mechanism resets and a second correction is performed. The secondary correction is based on the relative distance between the pneumatic gripper and the correction sleeve. The control strategy is adjusted so that the correction sleeve is the working end. The sleeve cylinder drives the correction sleeve to extend downward. The three-axis moving mechanism positions the correction sleeve above the pin of the primary correction. The pin enters the correction sleeve to complete the secondary correction.

2. The PCB board pin identification and adjustment device according to claim 1, characterized in that: The pneumatic gripper (14) has multiple support blocks (16) on its inner side.

3. The PCB board pin identification and adjustment device according to claim 1, characterized in that: The inner side of the corrective sleeve (15) has a trumpet-shaped structure.

4. The PCB board pin identification and adjustment device according to claim 1, characterized in that: In step 1, the preprocessing includes image enhancement, image smoothing and denoising, image grayscale conversion, and image thresholding.

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