A pressure control system for a pick-and-place machine

Abstract

The application provides a pressure control system of a pasting machine, comprising the pasting machine and a control device; the control device firstly acquires a working current of a second component control device measured by a current sensor and a first vibration signal collected by a vibration sensor; then analyzes the first vibration signal according to the working current of the second component control device, and decomposes to obtain a target vibration signal and motor noise; then determines pasting information of the second component according to the target vibration signal and the motor noise; and finally controls pasting pressure of the second component control device according to the pasting information. Through application of a vibration signal sensor, the vibration signal generated in the pasting process is collected, the pasting information is analyzed in combination with the working current of the pasting machine, and thus real-time monitoring of the pasting process is realized, and pasting errors are effectively avoided.

Description

Technical Field

[0001] This invention belongs to the field of production control technology, and in particular relates to a pressure control system for a bonding machine. Background Technology

[0002] Placement machines are essential equipment in the electronic component manufacturing process. They are used to place or insert electronic components when processing printed circuit boards, packaging integrated circuits, or mounting chips on substrates.

[0003] Current placement machine pressure monitoring technologies typically involve installing pressure sensors at the contact points between the placement machine and electronic components to measure the reaction force generated during placement. However, due to limitations in the monitoring accuracy of these pressure sensors, they usually only monitor whether the pressure sensor value exceeds a limit, stopping placement when the maximum value is exceeded. Therefore, current technologies struggle to achieve real-time monitoring and control of placement pressure during the placement process, resulting in a relatively high placement error rate. Summary of the Invention

[0004] In view of this, the present invention provides a pressure control system for a placement machine, which aims to solve the problem of high placement error rate in existing placement machines.

[0005] A first aspect of the present invention provides a pressure control system for a bonding machine, including a bonding machine and a control device; the bonding machine includes a first component control device and a second component control device; the bonding machine is used to bond a second component to a predetermined position of the first component; the second component control device is provided with a current sensor and a vibration sensor;

[0006] The control equipment is used for:

[0007] The operating current of the second component control device measured by the current sensor and the first vibration signal collected by the vibration sensor are obtained.

[0008] The first vibration signal is analyzed based on the operating current of the second component control device, and the target vibration signal and motor noise are obtained by decomposition.

[0009] Based on the target vibration signal and motor noise, determine the insertion information of the second component;

[0010] The insertion pressure of the second component control device is controlled based on the insertion information.

[0011] In some possible implementations, the control device is used for:

[0012] Based on the operating current, predict the standard vibration signal of the second component control device;

[0013] The first vibration signal is filtered to remove random noise;

[0014] Empirical mode decomposition is performed on the filtered first vibration signal to obtain multiple empirical mode components;

[0015] Calculate the correlation between each empirical modal component and the standard vibration signal;

[0016] The empirical mode components with correlation greater than a preset threshold are combined to obtain the motor noise, while the empirical mode components with correlation less than or equal to the preset threshold are combined to obtain the target vibration signal.

[0017] In some possible implementations, the control device is used for:

[0018] The operating current and the first vibration signal are input into a pre-established first neural network to decompose the target vibration signal and motor noise.

[0019] In some possible implementations, the control device is used for:

[0020] Peak picking is performed on the target vibration signal to obtain the first amplitude change vector of the target vibration signal;

[0021] Peak picking is performed on the motor noise to obtain the second amplitude change vector of the target vibration signal;

[0022] The first amplitude change vector is corrected based on the second amplitude change vector to obtain the third amplitude change vector;

[0023] The insertion position and insertion pressure of the second component are determined based on the third amplitude change vector.

[0024] In some possible implementations, the control device is used for:

[0025] The target vibration signal and motor noise are input into a pre-established second neural network to obtain the insertion position and insertion pressure of the second component.

[0026] In some possible implementations, the control device is used for:

[0027] Determine the theoretical insertion pressure based on the insertion position of the second component;

[0028] Determine the pressure control amount based on the insertion pressure and the theoretical insertion pressure;

[0029] The insertion pressure of the second component control device is controlled according to the pressure control quantity.

[0030] In some possible implementations, the control device is also used for:

[0031] When the second component reaches the predetermined insertion position, or when the insertion pressure of the second component exceeds the preset pressure, the second component control device is instructed to stop insertion.

[0032] In some possible implementations, a visual locator is provided within the second component control device; the control device is also used for:

[0033] Acquire positioning images captured by the visual locator;

[0034] The target insertion position is obtained by identifying the positioning image;

[0035] Move the second component to the target insertion position and begin insertion;

[0036] In some possible implementations, the control device is also used for:

[0037] When the second component reaches the target placement position, the placement pressure measured at this time is taken as the impact pressure.

[0038] The adjustment coefficient of the positioning image is calculated based on the impact pressure and the preset standard pressure.

[0039] The target insertion position is adjusted according to the adjustment factor.

[0040] In some possible implementations, the adjustment factor is:

[0041]

[0042] in, k To adjust the coefficient, x 1 represents impact pressure. x 2 represents the preset standard pressure. x 0 is the preset difference. S This is the area of ​​the mating surface of the second component.

[0043] The placement machine pressure control system provided in this embodiment of the invention first acquires the operating current of the second component control device measured by a current sensor and the first vibration signal collected by a vibration sensor; then, it analyzes the first vibration signal based on the operating current of the second component control device to decompose it into a target vibration signal and motor noise; next, it determines the placement information of the second component based on the target vibration signal and motor noise; finally, it controls the placement pressure of the second component control device based on the placement information. By applying a vibration signal sensor to collect the vibration signal generated during the placement process and combining it with the operating current of the placement machine to analyze the placement information, real-time monitoring of the placement process is achieved, effectively avoiding placement errors. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is a schematic diagram of the structure of the placement machine pressure control system provided in an embodiment of the present invention;

[0046] Figure 2 This is a flowchart illustrating the implementation of the control method corresponding to the control device provided in this embodiment of the invention. Detailed Implementation

[0047] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0048] Figure 1 This is a schematic diagram of the structure of the placement machine pressure control system provided in an embodiment of the present invention. Figure 1 As shown, in some embodiments, the placement machine pressure control system provided by the present invention can be applied to, but is not limited to, this application scenario. In this embodiment of the invention, the system includes: a placement machine 11 and a placement machine control device 12.

[0049] The placement machine includes a first component control device and a second component control device; the placement machine is used to place the second component into a predetermined position of the first component; the second component control device is equipped with a current sensor and a vibration sensor.

[0050] The first component can be a printed circuit board, substrate, integrated circuit substrate, etc., and is not limited here. The second component can be a resistor, capacitor, chip, etc., and is not limited here. The placement machine control equipment 12 can be a microcontroller, industrial control computer, computer, etc., and is not limited here.

[0051] Existing pressure sensor monitoring methods typically place the pressure sensor at the contact point between the placement machine and the electronic component. For example, when a component is picked up by a clamp, a pressure sensor is usually installed at the contact point between the clamp and the component to measure the pressure during the placement process. However, its monitoring is affected by the clamping force of the clamp itself, and frequent clamping operations can easily damage the high-precision pressure sensor. Therefore, it can only roughly monitor the maximum pressure during the placement process, and the placement is considered complete when the monitored pressure value exceeds the maximum pressure.

[0052] Furthermore, existing methods typically require a dedicated mounting slot for the pressure sensor on the clamp, making replacement complicated after a pressure sensor malfunctions. Additionally, the pressure sensor can only monitor whether placement is complete (or whether excessive pressure has caused device damage), and cannot monitor more detailed placement information. Therefore, this application makes the following improvements.

[0053] Figure 2 This is a flowchart illustrating the implementation of the control method corresponding to the control device provided in this embodiment of the invention. For example... Figure 2 As shown, in some embodiments, the control method corresponding to the control device includes the following steps:

[0054] S210, acquire the operating current of the second component control device measured by the current sensor and the first vibration signal collected by the vibration sensor.

[0055] In this embodiment of the invention, the first component control device may include a conveying device and a positioning device for conveying and fixing printed circuit boards, substrates, integrated circuit substrates, etc., and the second component control device may include a motion device, a positioning device, and an insertion execution device. During the insertion process, the insertion execution device (e.g., a clamp) first picks up the second component to be inserted, then the positioning device positions it according to the captured visual image to determine the required insertion position, and then the motion device moves it to the positioned position, so that the insertion execution device completes the insertion operation.

[0056] The present invention measures the operating current and a first vibration signal during the bonding process by incorporating a current sensor and a vibration sensor. The current sensor can be non-contact, and due to the transmissible nature of vibration signals, the vibration sensor can be installed at any location on the bonding actuator, preferably near the location where the second component is gripped.

[0057] Since the current sensor and vibration sensor of the present invention can measure without direct contact with the corresponding device, there is no need to set up a special mounting slot. They are compatible with a variety of different models of placement machines. Furthermore, due to their simple setup, replacement and repair are relatively simple when sensor failure occurs.

[0058] S220, the first vibration signal is analyzed based on the operating current of the second component control device, and the target vibration signal and motor noise are obtained by decomposition.

[0059] In this embodiment of the invention, the first vibration signal collected can be considered a fused signal of two types of signals. The first signal is the target vibration signal, that is, the vibration signal generated by contact when the second component is inserted into the first component. The second signal is the noise signal generated by the motor driving the control device of the second component.

[0060] S230, determine the insertion information of the second component based on the target vibration signal and motor noise.

[0061] The insertion information of the second component can usually be evaluated by analyzing the target vibration signal. However, due to the complexity of the actual production environment, the collected signals may contain some random environmental noise that is difficult to filter out, which affects the accuracy of the analysis results.

[0062] For the second component control device, motor noise is a relatively stable type of noise. With a fixed operating current and operating mode, the intensity and frequency of motor noise are typically constant. Therefore, motor noise can be used as the positive excitation noise of this invention to maintain the accuracy of the target vibration signal analysis.

[0063] In this embodiment of the invention, before and after the second component and the first component come into contact, and during the process of the change in the contact area between the two, the intensity of the motor noise near the second plug-in attachment will change slightly. This intensity difference can be collected as a positive excitation and added to the analysis of the target vibration signal.

[0064] S240, the placement pressure of the second component control device is controlled according to the placement information.

[0065] In this embodiment of the invention, a vibration signal sensor is used to collect the vibration signal generated during the placement process. Combined with the working current of the placement machine, the placement information is analyzed to achieve real-time monitoring of the placement process and effectively avoid placement errors.

[0066] In some embodiments, S220 may include: predicting a standard vibration signal of the second component control device based on the operating current; filtering the first vibration signal to remove random noise; performing empirical mode decomposition on the filtered first vibration signal to obtain multiple empirical mode components; calculating the correlation between each empirical mode component and the standard vibration signal; combining empirical mode components with a correlation greater than a preset threshold to obtain motor noise; and combining empirical mode components with a correlation less than or equal to the preset threshold to obtain a target vibration signal.

[0067] In this embodiment of the invention, the vibration signals generated during the insertion of different components are also different, while motor noise is usually relatively fixed. Motor vibration signals under different operating currents can be pre-collected. Then, during actual operation, the standard vibration signal of the motor can be determined by collecting the operating current. Since the change in motor noise during insertion is relatively small, after filtering and decomposing the first vibration signal, the empirical mode components obtained from the decomposition that have a high correlation with the standard vibration signal of the motor must belong to the components corresponding to the motor noise, while those with a low correlation can be classified as the components corresponding to the target vibration signal. The preset threshold is between [0.70, 0.95].

[0068] In some embodiments, S220 may include: inputting the operating current and the first vibration signal into a pre-established first neural network to decompose the target vibration signal and motor noise.

[0069] In this embodiment of the invention, a high-precision vibration signal sensor can be directly installed on the second component, and a similar high-precision vibration signal sensor can be installed on the motor to achieve vibration signal acquisition. Experiments are conducted on the insertion process of different components, with more than 10 sets of experiments for each component. The experimentally measured operating current and the first vibration signal are used as inputs, and the target vibration signal directly measured on the second component and the motor noise directly measured at the motor end are used as outputs to form a training sample.

[0070] In some embodiments, the insertion information includes insertion position and insertion pressure. Accordingly, S230 may include: peak picking of the target vibration signal to obtain a first amplitude change vector of the target vibration signal; peak picking of the motor noise to obtain a second amplitude change vector of the target vibration signal; correction of the first amplitude change vector based on the second amplitude change vector to obtain a third amplitude change vector; and determination of the insertion position and insertion pressure of the second component based on the third amplitude change vector.

[0071] In this embodiment of the invention, during the insertion process, as the insertion position deepens, the intensity of the vibration signal generated by friction or impact will change. Therefore, by picking up the peak value at a fixed frequency, a first amplitude change vector can be obtained to reflect the changes in the contact surface and contact pressure of the first and second components (the larger the contact area, the larger the amplitude of the target vibration signal; the greater the contact pressure, the larger the amplitude of the target vibration signal), i.e., the aforementioned insertion position and insertion pressure. To further improve accuracy, motor noise is introduced as positive excitation noise to correct the first amplitude change vector. The change in motor noise is also affected by the contact surface and contact pressure (the larger the contact area, the smaller the amplitude of the motor noise; the greater the contact pressure, the smaller the amplitude of the motor noise).

[0072] In some embodiments, the insertion information includes insertion position and insertion pressure. Accordingly, S230 may include: inputting the target vibration signal and motor noise into a pre-established second neural network to obtain the insertion position and insertion pressure of the second component.

[0073] In this embodiment of the invention, experimental data acquisition can be performed using image recognition technology and pressure sensors to collect the insertion position and insertion pressure under different conditions. Then, the operating current and the first vibration signal under these conditions are collected simultaneously. The target vibration signal and motor noise are analyzed to obtain the target vibration signal and motor noise. Finally, the target vibration signal and motor noise are used as inputs, and the experimentally measured insertion position and insertion pressure are used as outputs to train a second neural network.

[0074] In some embodiments, S240 may include: determining a theoretical placement pressure based on the placement position of the second component; determining a pressure control amount based on the placement pressure and the theoretical placement pressure; and controlling the placement pressure of the second component control device based on the pressure control amount.

[0075] In this embodiment of the invention, based on the placement position of the second component, it can be determined whether the second component needs to be inserted further downwards. Furthermore, based on the change in the placement position of the second component, it can be determined whether the placement speed needs to be adjusted. In this way, it can be analyzed whether the pressure needs to be increased or decreased, that is, the theoretical placement pressure can be obtained. The difference between the theoretical and the current placement pressure can be used to obtain the pressure control amount.

[0076] In some embodiments, in order to prevent damage caused by the bonding process, after S230, the method further includes instructing the second component control device to stop bonding when the bonding position of the second component reaches a predetermined position or the bonding pressure of the second component exceeds a preset pressure.

[0077] In some embodiments, a visual locator is provided within the second component control device. The corresponding method further includes: acquiring a positioning image captured by the visual locator; identifying the positioning image to obtain a target insertion position; and moving the second component to the target insertion position to begin insertion. Accordingly, after S230, the method further includes: when the second component's insertion position reaches the target insertion position, using the insertion pressure measured at this time as an impact pressure; calculating an adjustment coefficient for the positioning image based on the impact pressure and a preset standard pressure; and adjusting the target insertion position according to the adjustment coefficient.

[0078] In this embodiment of the invention, at the instant the second component is inserted into the first component, a contact impact signal is generated. The insertion pressure measured at this time is the impact pressure. If there is a deviation in the previous visual image positioning process, the difference between the impact pressure and the preset standard pressure will be greater than the preset difference. This indicates that there is a deviation in image positioning and adjustment is required.

[0079] In some embodiments, the adjustment factor can be calculated according to the following formula:

[0080]

[0081] in, kTo adjust the coefficient, x 1 represents impact pressure. x 2 represents the preset standard pressure. x 0 is the preset difference. S This is the area of ​​the mating surface of the second component. k Only values ​​greater than 0 are taken. If the measured impact pressure is less than the preset standard pressure, there is no need to calculate the adjustment coefficient.

[0082] The specific beneficial effects of this invention are as follows:

[0083] 1. By using a vibration signal sensor to collect vibration signals generated during the placement process, and combining this with the working current of the placement machine, placement information can be analyzed to achieve real-time monitoring of the placement process and effectively avoid placement errors.

[0084] 2. Since the current sensor and vibration sensor of the present invention can measure without direct contact with the corresponding device, there is no need to set up a special mounting slot. They are compatible with a variety of different models of placement machines. Furthermore, due to their simple setup, replacement and repair are relatively simple when sensor failure occurs.

[0085] 3. The monitoring function of this invention can not only monitor the insertion pressure in real time, but also roughly assess the insertion position, resulting in better monitoring performance.

[0086] 4. By monitoring the impact pressure, insertion failures caused by visual positioning errors can be effectively avoided.

[0087] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0088] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0089] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A pressure control system for a bonding machine, characterized in that, It includes a placement machine and a control device; the placement machine includes a first component control device and a second component control device; the placement machine is used to place the second component into a predetermined position of the first component; the second component control device is equipped with a current sensor and a vibration sensor; The control device is used to perform the following steps: The operating current of the second component control device measured by the current sensor and the first vibration signal collected by the vibration sensor are obtained. The first vibration signal is analyzed based on the operating current of the second component control device, and the target vibration signal and motor noise are decomposed. Based on the target vibration signal and the motor noise, the insertion information of the second component is determined; the insertion information includes the insertion position and the insertion pressure. The insertion pressure of the second component control device is controlled according to the insertion information.

2. The pressure control system for the placement machine according to claim 1, characterized in that, The control device is used for: Based on the operating current, predict the standard vibration signal of the second component control device; The first vibration signal is filtered to remove random noise; Empirical mode decomposition is performed on the filtered first vibration signal to obtain multiple empirical mode components; Calculate the correlation between each empirical modal component and the standard vibration signal; The empirical mode components with correlation greater than a preset threshold are combined to obtain the motor noise, while the empirical mode components with correlation less than or equal to the preset threshold are combined to obtain the target vibration signal.

3. The pressure control system for the placement machine according to claim 1, characterized in that, The control device is used for: The operating current and the first vibration signal are input into a pre-established first neural network to decompose the target vibration signal and motor noise.

4. The pressure control system for the placement machine according to claim 1, characterized in that, The control device is used for: Peak picking is performed on the target vibration signal to obtain the first amplitude change vector of the target vibration signal; Peak picking is performed on the motor noise to obtain the second amplitude change vector of the target vibration signal; The first amplitude change vector is corrected based on the second amplitude change vector to obtain the third amplitude change vector; The insertion position and insertion pressure of the second component are determined based on the third amplitude change vector.

5. The pressure control system for the placement machine according to claim 1, characterized in that, The control device is used for: The target vibration signal and the motor noise are input into a pre-established second neural network to obtain the insertion position and insertion pressure of the second component.

6. The pressure control system for the bonding machine according to claim 4 or 5, characterized in that, The control device is used for: Determine the theoretical insertion pressure based on the insertion position of the second component; The pressure control amount is determined based on the insertion pressure and the theoretical insertion pressure; The insertion pressure of the second component control device is controlled according to the pressure control amount.

7. The pressure control system for the bonding machine according to claim 4 or 5, characterized in that, The control device is also used for: When the second component reaches the predetermined position or the insertion pressure of the second component exceeds the preset pressure, the second component control device is instructed to stop insertion.

8. The pressure control system for the placement machine according to claim 1, characterized in that, The second component control device is equipped with a visual locator; the control device is also used for: Acquire the positioning image captured by the visual locator; The target insertion position is obtained by identifying the positioning image; Move the second component to the target insertion position to begin insertion.

9. The pressure control system for the placement machine according to claim 8, characterized in that, The control device is also used for: When the second component reaches the target insertion position, the insertion pressure measured at this time is taken as the impact pressure. The adjustment coefficient of the positioning image is calculated based on the impact pressure and the preset standard pressure. The target insertion position is adjusted according to the adjustment coefficient.

10. The pressure control system for the placement machine according to claim 9, characterized in that, The adjustment coefficient is: in, k To adjust the coefficient, x 1 represents impact pressure. x 2 represents the preset standard pressure. x 0 is the preset difference. S This is the area of ​​the mating surface of the second component.

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