A method and system for automatically compensating glue quantity according to seam width

Abstract

The method for automatically compensating glue amount according to the seam width disclosed in the first aspect of the present invention includes: calculating the total glue amount of glue dispensed; scanning the glue dispensing trajectory and collecting the actual gap widths of multiple points to calculate the reference seam width; calculating the actual glue dispensing speed of each section of the trajectory according to the reference speed, the reference seam width and the actual gap width of each point; controlling the running speed of the glue dispensing axis system to perform variable speed glue dispensing; the system for automatically compensating glue amount according to the seam width of the second aspect of the present invention includes a PC industrial computer, an electronic scale, a 3D line laser, a motion control board and a driver; the automatic glue compensation method of the present invention can adjust the speed of the glue dispensing axis system according to the actual seam width to automatically compensate for the glue amount, ensure that the glue fully fills the gap, and improve the bonding strength and sealing of the product; it is suitable for the glue dispensing requirements of different seam widths, and enhances the flexibility and adaptability of the glue dispensing system; the automatic glue compensation system of the present invention has a high degree of automation, reduces manual intervention, and improves work efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of glue dispensing, and in particular to a method and a system for automatically compensating glue quantity according to seam width. Background Art

[0002] With the rapid development of industry and technology, various industries have been striving for excellence in the gluing process. For example, in the mobile terminal industry, lens gluing is a typical example. While keeping the total amount of glue unchanged, the surrounding gaps after the lens is mounted are glued, bonded and sealed. The change in the width of the seam often makes it difficult to control the amount of glue. In the gluing process, for mass-produced products, due to unstable factors such as incoming materials or mounting, there are differences in the width of the surrounding seams after the lens is mounted. In the existing technology, it is usually necessary to manually adjust the amount of glue based on experience, and it is difficult to ensure the accuracy of the amount of glue. After gluing, there will be problems such as overflow or insufficient glue. If there is a problem, the product needs to be glued or repaired again, which not only has low work efficiency, but may even lead to product scrapping and increase manufacturing costs. Summary of the invention

[0003] In view of the shortcomings of the prior art, the present invention aims to provide a method and system for automatically compensating the amount of glue according to the gap width, so as to solve the problem that the amount of glue is difficult to accurately control due to the inconsistent gap width in the area to be glued in complex glue dispensing scenarios. To achieve the above purpose, the present invention adopts the following technical solutions:

[0004] In a first aspect, the present invention provides a method for automatically compensating glue quantity according to seam width, comprising the following steps: calculating the total glue quantity dispensed according to a glue dispensing trajectory and a reference speed;

[0005] Scan the dispensing track in sections and collect the actual gap widths at multiple points on the dispensing track;

[0006] Calculate the reference gap width based on the actual gap width of all points on the dispensing track;

[0007] According to the reference speed, reference gap width and actual gap width of each point, the actual dispensing speed of each track is calculated;

[0008] According to the total glue dispensing amount and the actual dispensing speed of each track, the running speed of the dispensing axis system is controlled to perform variable speed dispensing.

[0009] Optionally, according to the dispensing trajectory and the reference speed, calculating the total amount of glue dispensed includes:

[0010] Calculate the length of the dispensing track according to the obtained dispensing track shape information;

[0011] Set a baseline speed;

[0012] Establish the relationship model between glue quantity and reference speed;

[0013] The total glue volume is determined by simulated weighing based on the reference speed and dispensing track length.

[0014] Optionally, scanning the dispensing track and collecting the actual gap widths of multiple points on the dispensing track include:

[0015] According to the shape and length of the dispensing track, the dispensing track is divided into segments, and the scanning direction and method of each dispensing track are determined respectively;

[0016] Scan the dispensing track.

[0017] Optionally, according to the gap widths of all points on the dispensing track, the reference gap width is calculated including:

[0018] The reference gap width of the dispensing track is calculated by the arithmetic mean method. The gap widths of all points are added together and then divided by the total number of points.

[0019] Optionally, according to the reference speed, the reference gap width and the actual gap width of each point, the actual dispensing speed of each track is calculated including: according to the formula Calculate the actual dispensing speed of each track, where V is the actual dispensing speed, v 0 is the reference speed, W is the reference slit width, is the actual seam width.

[0020] Optionally, according to the total glue amount and the actual glue dispensing speed of each track, controlling the running speed of the glue dispensing axis system to perform variable speed glue dispensing includes:

[0021] Send speed instructions to the dispensing axis system to make the axis system run according to the actual dispensing speed of the current segment trajectory;

[0022] At the intersection of two trajectories, a linear acceleration and deceleration control strategy is adopted.

[0023] Optionally, calculating the reference gap width according to the gap widths of all points on the glue dispensing track includes: calculating the reference gap width of the glue dispensing track by using a weighted average method.

[0024] Optionally, calculating the reference gap width according to the gap widths of all points on the glue dispensing track includes: calculating the reference gap width of the glue dispensing track by using a median method.

[0025] In a second aspect, the present invention provides a system for automatically compensating glue quantity according to seam width, which is applied to the above-mentioned method for automatically compensating glue quantity according to seam width, and includes a PC industrial computer, an electronic scale, a 3D line laser, a motion control board, a driver and a shaft system motor;

[0026] The PC industrial computer is communicatively connected with the electronic scale, the 3D line laser and the motion control board;

[0027] The electronic scale is connected to the PC industrial computer for weighing the total amount of glue required for dispensing by simulated weighing;

[0028] The 3D line laser is connected to the PC industrial computer for scanning the three-dimensional contour information of the dispensing product and obtaining the seam width data of the dispensing track;

[0029] The motion control board is respectively connected to the PC industrial computer and the driver for receiving motion control instructions, parameters and data from the PC industrial computer, generating corresponding motion control signals and sending them to the driver;

[0030] The driver is in communication connection with the shaft motor and is used for receiving a control signal output by the motion control board to drive the shaft motor to move.

[0031] Optionally, there are multiple shaft system motors, and the multiple shaft system motors are respectively communicatively connected to the driver to execute position instructions of the driver and drive the corresponding shaft system motors to rotate.

[0032] The beneficial effect compared with the prior art is that, by adopting the above scheme, the method of automatically compensating the amount of glue according to the seam width of the present invention can adjust the speed of the glue dispensing axis system according to the actual seam width to automatically compensate for the amount of glue, thereby ensuring that the glue fully fills the gap and improves the bonding strength and sealing of the product; it is suitable for the glue dispensing requirements of different seam widths and enhances the flexibility and adaptability of the glue dispensing system; it has high accuracy and can accurately control the amount of glue and improve product yield; the system of automatically compensating the amount of glue according to the seam width of the present invention has a high degree of automation, reduces manual intervention, and improves work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic flow chart of a method for automatically compensating glue quantity according to seam width of the present invention;

[0034] Figure 2 It is a schematic diagram of the system framework for automatically compensating the glue amount according to the seam width of the present invention. DETAILED DESCRIPTION

[0035] To facilitate the understanding of the present invention, the present application is described in more detail below in conjunction with the accompanying drawings and specific embodiments; the accompanying drawings show preferred embodiments of the present application; however, the present application can be implemented in many different forms and is not limited to the embodiments described in this specification; on the contrary, the purpose of providing these embodiments is to make the understanding of the disclosed content of the present application more thorough and comprehensive.

[0036] It should be noted that, unless otherwise clearly stipulated and limited, the terms "set", "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection; it can be directly connected or indirectly connected through an intermediate medium, or it can be internal communication between two elements; for ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances; the terms "vertical", "horizontal", "left", "right", "front", "rear" and similar expressions used in this specification are for illustrative purposes only.

[0037] At the same time, it should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence; it should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0038] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those commonly understood by technicians in the technical field to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not used to limit this application.

[0039] First, as Figure 1 As shown, the present invention discloses a method for automatically compensating glue quantity according to seam width, comprising the following steps: calculating the total glue quantity of glue dispensed according to glue dispensing trajectory and reference speed;

[0040] Scan the dispensing track in sections and collect the actual gap widths at multiple points on the dispensing track;

[0041] Calculate the reference gap width based on the actual gap width of all points on the dispensing track;

[0042] According to the reference speed, reference gap width and actual gap width of each point, the actual dispensing speed of each track is calculated;

[0043] According to the total glue dispensing amount and the actual dispensing speed of each track, the running speed of the dispensing axis system is controlled to perform variable speed dispensing.

[0044] In this embodiment, the glue dispensing trajectory is usually pre-planned. On the automated production line, the shape and path of the product part that needs glue dispensing have been determined through programming or drawings, and the glue output of the glue gun is fixed. When the gap at the product glue dispensing position is large and a large amount of glue is required, the movement speed of the glue dispensing axis at this position will be slower, so that the glue gun will output more glue. Conversely, if the gap at the glue dispensing position is very narrow and so much glue is not needed, the speed of the glue dispensing axis calculated based on the narrow gap will be faster, and the glue output of the glue gun will be less.

[0045] In one embodiment, according to the dispensing track and the reference speed, calculating the total amount of glue dispensed includes:

[0046] According to the obtained dispensing track shape information, calculate the dispensing track length; for a track composed of simple straight line segments, use the distance between two points to calculate the length of each straight line segment, and then add them up to get the total length; calculate the length of all straight line segments in turn and sum them up. For a track containing arc segments, calculate the arc length according to the radius and center angle of the arc, and then add it up with the length of the straight line segment to get the total track length.

[0047] Set the reference speed; according to the experience and requirements of the dispensing process, set a reference speed v 0 This reference speed is usually determined through preliminary experimental verification, under the premise of ensuring the quality of glue dispensing, and taking into account factors such as production efficiency. For example, in a certain electronic equipment assembly line, after multiple tests, it was found that when the glue gun dispenses glue at a speed of 5mm / s, it can not only ensure the uniform distribution of glue, but also meet the beat requirements of the production line, so 5mm / s is set as the reference speed.

[0048] Establish a model for the relationship between glue volume and reference speed; determine the relationship between glue volume and dispensing speed through experiments. Place a container on an electronic scale, fix the glue gun on a device that can accurately control the moving speed, and make the glue gun dispense glue into the container at different speeds. At the same time, the electronic scale records the change in glue volume in real time. For example, let the glue gun dispense glue at speeds of 3mm / s, 4mm / s, 5mm / s, 6mm / s, and 7mm / s respectively. Each dispensing duration is the same, such as 10s, and record the increase in glue volume measured by the electronic scale each time. Based on these experimental data, draw a curve of the relationship between glue volume and dispensing speed. Assuming that the two are linearly related within a certain range, the relationship Q=k×v+b is determined by mathematical methods such as linear regression, where Q is the glue volume per unit time (ml / s), k is a proportional constant related to the properties of the glue (such as density, viscosity) and the characteristics of the dispensing equipment (such as the size of the glue gun nozzle), v is the dispensing speed (mm / s), and b is the intercept. Generally speaking, when the performance of the glue gun is stable, the b value is small or even close to zero, that is, the amount of glue is mainly determined by the speed.

[0049] According to the reference speed v0 The total glue volume is determined by simulated weighing based on the length of the dispensing track. A virtual dispensing operation is performed according to the set reference speed and dispensing track. This step does not actually perform dispensing, but simulates the process of increasing the glue volume through mathematical calculations based on the previously determined relationship between the track length, glue volume and speed. The control system determines the total glue volume based on the length of the dispensing track L. totaL and the reference speed v 0 , calculate the time required for dispensing t = L total / v 0 , and then calculate the total glue amount based on the glue amount and speed relationship model During the simulated dispensing process, the control system transmits the calculated glue volume change value to the electronic scale in real time. The electronic scale displays the corresponding weight reading according to the received data to realize simulated weighing.

[0050] In one embodiment, scanning the dispensing track and collecting the actual gap widths of multiple points on the dispensing track includes:

[0051] According to the shape and length of the dispensing track, the dispensing track is segmented, and the direction and method of scanning each dispensing track are determined separately; if the dispensing track is linear, it can be scanned unidirectionally or bidirectionally along the linear direction; if it is a circular or annular track, a circular scanning method can be used. For complex curved tracks, it may be necessary to decompose them into multiple simple line segments and curve segments, and adopt appropriate scanning strategies for each. For example, for a dispensing track similar to an "S" shape, it can be regarded as two reverse curved segments and a connecting line segment. Each curved segment is first scanned along the tangent direction of the curve, and then the connecting line segment is scanned in a straight line.

[0052] Use a 3D line laser scanner to scan the dispensing track;

[0053] According to the gap width information on the dispensing track, the distribution of points should be planned reasonably. In areas where the gap width varies greatly, such as the starting end, the end end, and the transition area of ​​the width change, more collection points should be set. For relatively uniform gap areas, the point interval can be appropriately reduced. A combination of equal spacing and non-equal spacing can be used. For example, within the first 10% of the length of the starting end of the gap, a collection point is set every 1mm; in the relatively uniform part in the middle, a point is set every 5mm; in the last 10% of the length close to the end, a point is set every 1mm. At the same time, according to the expected maximum and minimum widths of the gap, determine the accuracy requirements for the data collected at each point.

[0054] In one embodiment, according to the gap widths of all points on the dispensing track, calculating the reference gap width includes:

[0055] The reference gap width of the dispensing track is calculated by the arithmetic mean method. The gap widths of all points are added together and then divided by the total number of points. For example, the actual gap width data collected at 40 points on the dispensing track are: w 1 、w 2 、w 3 ...w 40 , then the reference slit width W = (w 1 +w 2 +w 3 +…+w 40 ) / 40.

[0056] In one embodiment, according to the reference speed, the reference gap width and the actual gap width of each point, calculating the actual dispensing speed of each track includes:

[0057] According to the formula Calculate the actual dispensing speed of each track, where V is the actual dispensing speed, v 0 is the reference speed, W is the reference slit width, is the actual seam width.

[0058] In one embodiment, according to the total glue amount dispensed and the actual glue dispensing speed of each track, controlling the running speed of the glue dispensing axis system to perform variable speed glue dispensing includes:

[0059] Send a speed command to the dispensing axis system to make the axis system run at the actual dispensing speed of the current trajectory; use the calculated dispensing time and actual dispensing speed of each trajectory as parameters. For each trajectory, when dispensing starts, the control system sends a speed command to the motor driver of the dispensing axis system to make the axis system run at the actual dispensing speed and start the timer at the same time. When the dispensing time is reached, the control system switches to the speed and time setting of the next trajectory, and so on to complete the entire variable speed dispensing process.

[0060] At the intersection of the two trajectories, a linear acceleration and deceleration control strategy is used to make the dispensing speed transition smoothly to avoid uneven dispensing or glue gun jitter caused by sudden changes in speed. When switching speeds, a transition time (set to Δ t ), during this time, the speed of the dispensing axis changes from the current speed line v i The speed v of the change to the next segment i +1. For example, during the transition time, the formula for the speed change can be (where t is the time variable within the transition period, 0≤t≤Δ t )

[0061] In one embodiment, calculating the reference gap width according to the gap widths of all points on the dispensing track includes: calculating the reference gap width of the dispensing track by using a weighted average method.

[0062] When the gap widths at different points have different importance to the overall result, the weighted average method can be used. For example, the gap width data at certain key parts of the dispensing trajectory (such as the starting and ending ends of the gap, or parts that are subject to greater stress) may be more important and need to be given a higher weight.

[0063] Let the weight of each point be k i (i=1,2,...,n,) and The calculation formula of weighted average base seam width is: Assume that in a dispensing trajectory, the weights of the starting and ending points are 0.3, the weights of the three middle points are 0.1, and the gap width data is the same as the example in the arithmetic mean method above, then the reference gap width W = (0.3×2+0.3×2+0.1×2.2+0.1×1.9+0.1×2.1) = 2.02mm.

[0064] In one embodiment, according to the gap widths of all points on the dispensing track, calculating the reference gap width includes:

[0065] The median method is used to calculate the reference gap width of the dispensing track. The gap width data of all points are arranged in order from small to large (or from large to small). If the number of data points is an odd number, the median is the number in the middle position after sorting; if it is an even number, the median is the average of the two middle numbers. The median can avoid the influence of outliers on the calculation of the reference gap width to a certain extent.

[0066] In a second aspect, the present invention discloses a system for automatically compensating glue quantity according to seam width, which is applied to the above-mentioned method for automatically compensating glue quantity according to seam width, and includes a PC industrial computer, an electronic scale, a 3D line laser, a motion control board, a driver and a shaft system motor;

[0067] The PC industrial computer is communicatively connected with the electronic scale, the 3D line laser and the motion control board;

[0068] The electronic scale is connected to the PC industrial computer for weighing the total amount of glue required for dispensing by simulated weighing;

[0069] The 3D line laser is connected to the PC industrial computer for scanning the three-dimensional contour information of the dispensing product and obtaining the seam width data of the dispensing track;

[0070] The motion control board is respectively connected to the PC industrial computer and the driver for receiving motion control instructions, parameters and data from the PC industrial computer, generating corresponding motion control signals and sending them to the driver;

[0071] The driver is in communication connection with the shaft motor and is used for receiving a control signal output by the motion control board to drive the shaft motor to move.

[0072] When working, the PC industrial computer sends a simulated weighing instruction to the electronic scale according to the preset dispensing track and reference speed information. The electronic scale simulates the process of the glue gun moving along the dispensing track at the reference speed according to the received instructions and information, and uses its high-precision sensor to monitor the change of "glue amount" in real time. After the simulated dispensing is completed, the electronic scale transmits the total glue amount data required for dispensing back to the PC industrial computer through the communication link.

[0073] The PC sends a scanning command to the 3D line laser to perform a three-dimensional contour scan of the product area to be glued, and extract the seam width data of each point on the glue track. These seam width data are transmitted back to the PC in real time in the form of digital signals.

[0074] After receiving the total glue quantity data from the electronic scale and the seam width data from the 3D line laser, the PC enters the core data processing link. First, it calculates the reference seam width according to the seam width data of all points according to the preset algorithm (such as arithmetic mean method, weighted average method, etc.). Then, based on the intrinsic relationship model between glue quantity, seam width and dispensing speed, combined with the reference speed, reference seam width and the actual seam width of each point, the dispensing track is segmented and the actual dispensing speed of each track is accurately calculated.

[0075] The PC industrial computer sends the calculated actual dispensing speed of each trajectory and the corresponding motion control parameters (such as target position, acceleration, etc.) to the motion control board.

[0076] After receiving these instructions and data, the motion control board immediately starts the built-in motion control algorithm, generates corresponding motion control signals according to the motor type (such as stepper motor or servo motor), and sends the generated motion control signals to the driver through the communication interface.

[0077] After receiving the signal, the driver drives the shaft motor to move according to the predetermined trajectory and speed. The shaft motor drives the glue gun to move precisely to the starting position of dispensing, and then, under the continuous drive of the motion control signal, the speed dispensing operation is performed at a precisely calculated speed along the dispensing trajectory. During the dispensing process, the glue gun dispenses glue according to the actual dispensing speed of each track. For example, when the gap at the dispensing position of the product is large and a large amount of glue is required, the speed at this position will be slower, so that the amount of glue will be more. Conversely, if the gap at the dispensing position is very narrow and so much glue is not needed, the dispensing speed calculated for the narrow gap will be faster and the amount of glue will be less, thereby achieving automatic compensation for the amount of glue in areas with different gap widths.

[0078] In one embodiment, there are multiple shaft motors, and the multiple shaft motors are respectively connected to the driver for executing the position instruction of the driver to drive the corresponding shaft motors to rotate. The multiple shaft motors include at least an X-axis drive motor, a Y-axis drive motor, and a Z-axis drive motor, and the driver can simultaneously drive multiple shaft motors to move in coordination.

[0079] It should be noted that the above-mentioned technical features are further combined with each other to form various embodiments not listed above, which are all deemed to be within the scope of the present invention; and, for ordinary technicians in this field, they can be improved or transformed according to the above description, and all these improvements and transformations should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A method for automatically compensating glue amount according to seam width, characterized in that: The following steps are involved: Calculate the total glue amount dispensed based on the dispensing trajectory and reference speed; Scan the dispensing track in sections and collect the actual gap widths at multiple points on the dispensing track; Calculate the reference gap width based on the actual gap width of all points on the dispensing track; According to the reference speed, reference gap width and actual gap width of each point, the actual dispensing speed of each track is calculated; According to the total glue dispensing amount and the actual dispensing speed of each track, the running speed of the dispensing axis system is controlled to perform variable speed dispensing.

2. The method for automatically compensating the amount of glue according to the seam width according to claim 1, characterized in that: According to the dispensing trajectory and the reference speed, the total amount of glue dispensed is calculated including: Calculate the length of the dispensing track according to the obtained dispensing track shape information; Set a baseline speed; Establish the relationship model between glue quantity and reference speed; The total glue volume is determined by simulated weighing based on the reference speed and dispensing track length.

3. The method for automatically compensating glue amount according to seam width according to claim 1, characterized in that: Scan the dispensing track and collect the actual gap width of multiple points on the dispensing track, including: According to the shape and length of the dispensing track, the dispensing track is divided into segments, and the scanning direction and method of each dispensing track are determined respectively; Scan the dispensing track.

4. The method for automatically compensating glue amount according to seam width according to claim 1, characterized in that: According to the gap width of all points on the dispensing track, the base gap width is calculated including: The reference gap width of the dispensing track is calculated by the arithmetic mean method. The gap widths of all points are added together and then divided by the total number of points.

5. The method for automatically compensating glue amount according to seam width according to claim 1, characterized in that: According to the reference speed, reference gap width and the actual gap width of each point, the actual dispensing speed of each track is calculated including: According to the formula Calculate the actual dispensing speed of each track, where V is the actual dispensing speed, v0 is the reference speed, and W is the reference seam width. is the actual seam width.

6. The method for automatically compensating glue amount according to seam width according to claim 1, characterized in that: According to the total glue amount and the actual glue dispensing speed of each track, the running speed of the glue dispensing axis system is controlled to perform variable speed glue dispensing, including: Send speed instructions to the dispensing axis system to make the axis system run according to the actual dispensing speed of the current segment trajectory; At the intersection of two trajectories, a linear acceleration and deceleration control strategy is adopted.

7. The method for automatically compensating glue amount according to seam width according to claim 1, characterized in that: According to the gap widths of all points on the dispensing track, the reference gap width is calculated, including: using the weighted average method to calculate the reference gap width of the dispensing track.

8. The method for automatically compensating glue amount according to seam width according to claim 1, characterized in that: According to the gap widths of all points on the dispensing track, the reference gap width is calculated, including: using the median method to calculate the reference gap width of the dispensing track.

9. A system for automatically compensating glue quantity according to seam width, applied to a method for automatically compensating glue quantity according to seam width according to any one of claims 1 to 8, characterized in that: Including PC industrial computers, electronic scales, 3D line lasers, motion control boards, drivers and shaft motors; The PC industrial computer is communicatively connected with the electronic scale, the 3D line laser and the motion control board; The electronic scale is connected to the PC industrial computer for weighing the total amount of glue required for dispensing by simulated weighing; The 3D line laser is connected to the PC industrial computer for scanning the three-dimensional contour information of the dispensing product and obtaining the seam width data of the dispensing track; The motion control board is respectively connected to the PC industrial computer and the driver for receiving motion control instructions, parameters and data from the PC industrial computer, generating corresponding motion control signals and sending them to the driver; The driver is in communication connection with the shaft motor and is used for receiving a control signal output by the motion control board to drive the shaft motor to move.

10. The system for automatically compensating glue quantity according to seam width according to claim 9, characterized in that: There are multiple shaft system motors, and the multiple shaft system motors are respectively connected to the driver for communication, and are used to execute the position instruction of the driver to drive the corresponding shaft system motors to rotate.

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