CN117086482A - Iteration-based laser welding temperature control method, controller, equipment and media - Google Patents

Abstract

The scheme relates to providing an iteration-based laser welding temperature control method, a controller, equipment and a medium, wherein the temperature control method specifically comprises the following steps: and receiving a target temperature curve and a real-time temperature, calculating an iteration temperature error according to the target temperature curve and the real-time temperature, carrying out iteration according to the iteration temperature error and the last iteration output power to obtain the current iteration output power, taking the current iteration output power as a control laser power until the iteration temperature error is smaller than a preset value, outputting a laser beam according to the control laser power, and carrying out welding by utilizing the laser beam. The application can improve the control precision, stability and adaptability of the welding temperature and is applied to the field of welding control.

Description

Iteration-based laser welding temperature control method, controller, equipment and media

Technical field

The present invention relates to the field of welding control, and in particular to an iteration-based laser welding temperature control method, controller, equipment and medium.

Background technique

At present, commonly used laser welding temperature control methods mainly include open-loop control methods based on power adjustment and closed-loop control methods based on infrared detection. Among them, the open-loop control method based on power adjustment mainly adjusts the output power of the laser to change the laser beam on the processing. The energy input of the parts affects the molten pool temperature. This method is simple and easy to implement, but is affected by factors such as the material, thickness, and surface state of the workpiece, making it difficult to achieve accurate and stable temperature control.

The closed-loop control method based on infrared detection detects the infrared heat radiation of the laser to the workpiece, and realizes PID closed-loop control through the calculated laser welding temperature and detection temperature. It can effectively control the laser welding temperature to fluctuate within the set range, but the accuracy is low. And the stability and adaptability are poor.

Contents of the invention

In view of this, the purpose of the present invention is to provide an iteration-based laser welding temperature control method, controller, equipment and medium, which can improve the control accuracy, stability and adaptability of the welding temperature.

In order to solve the above problems, in the first aspect, the present invention provides an iteration-based laser welding temperature control method, which includes the following steps:

Receive the target temperature curve and real-time temperature, and calculate the iterative temperature error based on the target temperature curve and real-time temperature;

Iterate according to the iteration temperature error and the last iteration output power to obtain the current iteration output power. Until the iteration temperature error is less than the preset value, the current iteration output power is used as the control laser power;

A laser beam is output according to the controlled laser power, and the laser beam is used to perform welding.

Optionally, calculating the iterative temperature error based on the target temperature curve and real-time temperature specifically includes:

Obtain a target temperature from the target temperature curve;

Difference the target temperature and the real-time temperature to obtain the iteration temperature error of the current iteration.

Optionally, the iteration is performed according to the iteration temperature error and the last iteration output power to obtain the current iteration output power, which specifically includes:

Multiply the iteration temperature error by the learning gain to obtain the current iteration correction value;

The current iteration output power is obtained according to the last iteration output power and the current iteration correction value; the last iteration output power of the first iteration is the initial laser power.

Optionally, obtaining the current iteration output power based on the last iteration output power and the current iteration correction value specifically includes:

Add the last iteration output power and the current iteration correction value to obtain the initial output power of the current iteration;

Filter the initial output power of the current iteration to obtain the current iteration output power.

Optionally, until the preset conditions are met, the current iteration output power is used as the control laser power, specifically including:

Until the iteration temperature error is less than the error preset value or until the number of iterations is greater than the number of preset values;

The current iteration output power is used as the control laser power.

In order to solve the above problems, in the second aspect, the present invention provides an iteration-based laser welding temperature controller, including a receiving module, an iteration module and a laser output module, wherein,

The receiving module is used to receive the target temperature curve and real-time temperature, and calculate the iterative temperature error according to the target temperature curve and real-time temperature;

The iteration module is used to iterate according to the iteration temperature error and the last iteration output power to obtain the current iteration output power. Until the iteration temperature error is less than a preset value, the current iteration output power is used as the control laser power. ;

The laser output module is used to output a laser beam according to the controlled laser power, and use the laser beam to perform welding.

In order to solve the above problems, in the third aspect, the present invention provides a temperature measurement system, a temperature controller, a laser transmitter, a visualization device and a workbench, and the temperature measurement system is connected to the temperature controller and the visualization device, The temperature controller is connected to the laser emitter, and the visualization device is also connected to the workbench;

The temperature measurement system is used to detect real-time temperature;

The temperature controller is used to implement any one of the iteration-based laser welding temperature control methods;

The laser emitter is used to form a laser beam according to the output power of the temperature controller;

The visualization device is used to display the real-time temperature, iterative temperature error and the output power of each iteration;

The workbench is used to place welding materials.

Optionally, the temperature measurement system includes an image acquisition module and an image processing module;

The image acquisition module is used to acquire the temperature image of the welding object;

The image processing module is used to obtain real-time temperature from the temperature image.

In order to solve the above problems, in a fourth aspect, the present invention provides an electronic device. The electronic device includes a memory and a processor. The memory stores a computer program. When the processor executes the computer program, it implements a method based on Iterative laser welding temperature control method any one of the methods described.

In order to solve the above problems, in a fifth aspect, the present invention provides a computer-readable storage medium in which a processor-executable program is stored, and the processor-executable program, when executed by the processor, is used to perform a The method described in any one of the iterative laser welding temperature control methods.

Implementing the present invention includes the following beneficial effects: the present invention receives a target temperature curve and a real-time temperature, calculates an iterative temperature error according to the target temperature curve and the real-time temperature, and iterates according to the iterative temperature error and the last iteration output power, Obtain the current iteration output power until the iteration temperature error is less than the preset value, use the current iteration output power as the control laser power, output the laser beam according to the control laser power, use the laser beam for welding, and use the previous actual The error between the temperature and the target temperature corrects the output power to obtain the output temperature of this iteration. Multiple iterations are performed to improve the control accuracy of the welding temperature, and also improve the stability and adaptability of the output power.

Description of the drawings

Figure 1 is a flow chart of an iteration-based laser welding temperature control method provided by the present invention;

Figure 2 is an iterative schematic diagram of an iteration-based laser welding temperature control method provided by the present invention;

Figure 3 is a schematic structural diagram of an iteration-based laser welding temperature controller provided by the present invention;

Figure 4 is a schematic structural diagram of a laser welding equipment provided by the present invention;

Figure 5 is a target temperature curve diagram of an iterative-based laser welding temperature control method provided by the present invention;

Figure 6 is an error curve diagram of an iteration-based laser welding temperature control method and other methods provided by the present invention;

Figure 7 is a schematic structural diagram of an electronic device provided by the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. The step numbers in the following embodiments are only set for the convenience of explanation. The order between the steps is not limited in any way. The execution order of each step in the embodiments can be adapted according to the understanding of those skilled in the art. sexual adjustment.

In order to solve the above problems, in some embodiments, as shown in Figure 1 and Figure 2, Figure 1 is a flow chart of an iteration-based laser welding temperature control method, and Figure 2 is an iteration-based laser welding temperature control method. Schematic diagram: The invention provides an iteration-based laser welding temperature control method, which includes the following steps:

S100. Receive the target temperature curve and real-time temperature, and calculate the iterative temperature error according to the target temperature curve and real-time temperature.

The target temperature curve is obtained through multiple control experiences. In this embodiment, it is as shown in formula (1).

Among them, T _tar (t) is the target temperature function, and the unit period is 0.001s.

The real-time temperature is the temperature of the welding head corresponding to each unit cycle.

S200: Perform iteration according to the iteration temperature error and the last iteration output power to obtain the current iteration output power until the preset conditions are met, and use the current iteration output power as the control laser power.

Specifically, the iteration temperature error of each iteration is used to correct the output power of the previous iteration to obtain the output power of the ongoing iteration, that is, the current output power is optimized based on the last control information, so that past control experience can be utilized.

After N iterations, if the iteration temperature error is less than the preset value, the output power obtained based on the iteration temperature error less than the preset value will be used as the laser control power to control the laser.

In some embodiments, the number of iterations can be preset, such as M times. After M iterations, the output power obtained can be used as the laser control power for controlling the laser.

S300: Output a laser beam according to the control of the laser power, and use the laser beam to perform welding.

In order to solve the above problem, in some embodiments, step S100 calculates the iterative temperature error according to the target temperature curve and the real-time temperature, specifically including:

S110. Obtain the target temperature from the target temperature curve.

Specifically, according to the time of the current iteration, a certain iteration target temperature T _tar (k) of the current iteration stage is obtained based on the above equation (1).

S120: Difference the target temperature and the real-time temperature to obtain the iteration temperature error of the current iteration.

Specifically, the iterative temperature error is obtained according to equation (2).

e _i+1 (k)＝T _tar (k) - T _i (k) (2)

Among them, e _i+1 (k) is the iteration temperature error of the (i+1)th iteration, T _tar (k) is the iteration target temperature at time k, and T _i (k) is the temperature error after the i-th iteration through the i-th iteration. The real-time temperature obtained by welding with the output power obtained by iterations.

In order to solve the above problem, in some embodiments, in step S200, iteration is performed according to the iteration temperature error and the last iteration output power to obtain the current iteration output power, which specifically includes:

S210. Multiply the iteration temperature error by the learning gain to obtain the current iteration correction value.

Specifically, the current iteration correction value is shown in equation (3).

L×e _i+1 (k)(3)

Among them, L is the learning gain, e _i+1 (k) is the iteration temperature error.

S220. Obtain the current iteration output power according to the last iteration output power and the current iteration correction value; the last iteration output power of the first iteration is the initial laser power.

Specifically, the current iteration correction value is used to correct the output power of the previous iteration to obtain the current iteration output power.

In the first iteration, the initial laser power is used as the output power of the previous iteration, and the current iteration correction value is used to correct the initial laser power to obtain the current iteration output power of the first iteration. In this embodiment, the initial laser power is 0.

In order to solve the above problem, in some embodiments, in step S220, the current iteration output power is obtained based on the last iteration output power and the current iteration correction value, which specifically includes:

S221. Add the last iteration output power and the current iteration correction value to obtain the initial output power of the current iteration.

Specifically, when the first iteration is performed with the real-time temperature as the ambient temperature and the initial laser power as 0, in this embodiment, the ambient temperature is 15°C as an example, as shown in equation (4).

u ₁ (k)＝0+L×e ₁ (k) (4)

Among them, u ₁ (k) is the output power of the first iteration, L is the learning gain, and e ₁ (k) is the iteration temperature error of the first iteration.

For each iteration after the first iteration, according to equation (5), the initial output power u _i+1 (k) of the current iteration is obtained.

u _i+1 (k)＝u _i (k)+L×e _i+1 (k)(5)

Among them, u _i+1 (k) is the initial output power of the (i+1)-th iteration, u _i (k) is the output power of the i-th iteration, e _i+1 (k) is the (i+1)-th iteration ) iteration temperature error, L is the learning gain.

S222. Filter the initial output power of the current iteration to obtain the current iteration output power.

Specifically, as shown in Figure 2, in the figure, the x-axis of coordinate 1 represents the sampling time, the y-axis represents the number of iterations, and the z-axis represents the output power. The x-axis of coordinate 2 represents the sampling time, the y-axis represents the number of iterations, and the z-axis represents the temperature error, L represents the learning gain, Q represents the filter function, P represents the control object, r represents external interference, and R represents the reference input. The initial output temperature of each iteration is passed through a filter function to obtain the current iteration output power, and It serves as the item to be corrected in the next iteration.

In order to solve the above problem, in some embodiments, until the preset condition is met in step S200, the current iterative output power is used as the control laser power, specifically including:

Until the iteration temperature error is less than the error preset value or until the number of iterations is greater than the number preset value, the current iteration output power is used as the control laser power.

Among them, the error preset value can be set according to the control accuracy, and the number preset value is the maximum number of iterations, which can be obtained based on experimental experience.

In order to solve the above problems, in some embodiments of the present invention, as shown in Figure 3, Figure 3 is a structural schematic diagram of a laser welding temperature controller based on iteration. In the figure, Ttar is the target temperature, and u is the temperature of each iteration. Output power, T is real-time temperature. The present invention provides an iterative-based laser welding temperature controller, including a receiving module, an iterative module and a laser output module, where,

The receiving module is used to receive the target temperature curve and real-time temperature, and calculate the iterative temperature error according to the target temperature curve and real-time temperature;

The iteration module is used to iterate according to the iteration temperature error and the last iteration output power to obtain the current iteration output power. Until the iteration temperature error is less than a preset value, the current iteration output power is used as the control laser power. ;

The laser output module is used to output a laser beam according to the controlled laser power, and use the laser beam to perform welding.

In order to solve the above problems, in some embodiments of the present invention, as shown in Figure 4, Figure 4 is a schematic structural diagram of a laser welding equipment. In the figure, A is the welding object and B is the laser beam. The present invention provides a laser welding equipment. Welding equipment, including a temperature measurement system, a temperature controller, a laser emitter, a visualization device, and a workbench. The temperature measurement system is connected to the temperature controller and the visualization device, and the temperature controller is connected to the laser emitter. , the visualization device is also connected to the workbench;

The temperature measurement system is used to detect real-time temperature;

The temperature controller is used to implement any one of the iteration-based laser welding temperature control methods;

The laser emitter is used to form a laser beam according to the output power of the temperature controller;

The visualization device is used to display the real-time temperature, iterative temperature error and the output power of each iteration;

The workbench is used to place welding materials.

Among them, placement includes receiving, fixing and moving. Specifically, the welding object is fixed on the workbench. A mobile device is installed on the workbench to move the welding object to the laser heating point, or the workbench is moved. Move the fixed welding object to the laser heating point.

Specifically, the temperature measurement system detects the real-time temperature of the solder joint in real time, and transmits the real-time temperature to the temperature controller and the visualization device. The temperature controller implements any of the methods described in any one of the iterative-based laser welding temperature control methods, To obtain controlled laser power, the semiconductor laser beam forms a laser beam by controlling the laser power. The laser beam is focused on the solder joint on the workbench through the focusing mirror in the vision system. The motor controller on the workbench moves the solder joint to the center of the laser beam. below, and modify the defocus amount to bring the solder paste to the ideal temperature. In a complete system, data collection, platform positioning and vision systems can all be controlled by the visualization device, which can also display real-time temperature, iteration temperature error and output power of each iteration.

In order to solve the above problems, in some embodiments of the present invention, the temperature measurement system includes an image acquisition module and an image processing module;

The image acquisition module is used to acquire the temperature image of the welding object;

The image processing module is used to obtain real-time temperature from the temperature image.

Specifically, in this embodiment, a camera or the like is used to obtain a temperature image of the surface of the welding object, and the image processing module analyzes the temperature image through image recognition to obtain the real-time temperature of the welding point.

It should be noted that the temperature measurement system can also be an infrared detector or other temperature sensor, and the real-time temperature of the welding point is obtained through infrared detection and other methods.

As shown in Figures 5 and 6, Figure 5 is a target temperature curve of an iterative-based laser welding temperature control method, and Figure 6 is an error curve of an iterative-based laser welding temperature control method and other methods.

Table 3 is the error comparison of PID control, feedforward-feedback control and iterative learning control. It can be seen from Figure 6 and Table 3 that the temperature error curves of PID control and feedforward-feedback control overlap after starting to heat for a period of time, with For similar temperature error changes, the present invention uses historical data to perform multiple iterative learning and updates, thereby adapting to changes in laser parameters or workpieces, improving the accuracy and stability of welding temperature control, and reducing the accuracy requirements of the temperature controller. Compared with open-loop control and traditional PID temperature control, the present invention improves the temperature accuracy during laser welding and is suitable for controlling the welding temperature during the laser welding process.

In order to solve the above problems, in some embodiments, as shown in Figure 7, Figure 7 is a schematic structural diagram of an electronic device provided by the present invention. The present invention also provides an electronic device, the electronic device includes a processor 10 and a memory 20. The memory 20 stores a computer program. When the processor 10 executes the computer program, it implements any of the methods described in the above method embodiments.

Among them, the memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer executable programs. The memory may include high-speed random access memory and may also include non-transitory memory, such as at least one magnetic disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, the memory optionally includes remote memory located remotely from the processor, and these remote memories may be connected to the processor via a network. Examples of the above-mentioned networks include but are not limited to the Internet, intranets, local area networks, mobile communication networks and combinations thereof.

In addition, embodiments of the present application also disclose a computer program product or computer program, which is stored in a computer-readable storage medium. The processor of the computer device can read the computer program from the computer-readable storage medium, and the processor executes the computer program, so that the computer device performs the above method. Similarly, the contents in the above method embodiment are applicable to this storage medium embodiment. The specific functions implemented by this storage medium embodiment are the same as those in the above method embodiment, and the beneficial effects achieved are the same as those achieved by the above method embodiment. The beneficial effects are also the same.

The present invention also provides a computer-readable storage medium in which a processor-executable program is stored. When executed by the processor, the processor-executable program is used to perform any of the above method embodiments. method.

It can be understood that all or some steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and appropriate combinations thereof. Some or all of the physical components may be implemented as software executed by a processor, such as a central processing unit, a digital signal processor, or a microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit . Such software may be distributed on computer-readable media, which may include computer storage media (or non-transitory media) and communication media (or transitory media). As is known to those of ordinary skill in the art, the term computer storage media includes volatile and nonvolatile media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. removable, removable and non-removable media. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, Digital Versatile Disk (DVD) or other optical disk storage, magnetic cassettes, tapes, disk storage or other magnetic storage devices, or may Any other medium used to store the desired information and that can be accessed by a computer. Additionally, it is known to those of ordinary skill in the art that communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media .

The above is a detailed description of the preferred implementation of the present invention, but the present invention is not limited to the embodiments. Those skilled in the art can also make various equivalent modifications or substitutions without violating the spirit of the present invention. , these equivalent modifications or substitutions are included in the scope defined by the claims of this application.

Claims (10)

1. An iteration-based laser welding temperature control method, characterized by including the following steps: Receive the target temperature curve and real-time temperature, and calculate the iterative temperature error based on the target temperature curve and real-time temperature; Iterate according to the iteration temperature error and the last iteration output power to obtain the current iteration output power until the preset conditions are met, and the current iteration output power is used as the control laser power; A laser beam is output according to the controlled laser power, and the laser beam is used to perform welding. 2. The method according to claim 1, wherein calculating the iterative temperature error according to the target temperature curve and real-time temperature specifically includes: Obtain a target temperature from the target temperature curve; Difference the target temperature and the real-time temperature to obtain the iteration temperature error of the current iteration. 3. The method according to claim 1, wherein the current iteration output power is obtained by iterating according to the iteration temperature error and the last iteration output power, specifically including: Multiply the iteration temperature error by the learning gain to obtain the current iteration correction value; The current iteration output power is obtained according to the last iteration output power and the current iteration correction value; the last iteration output power of the first iteration is the initial laser power. 4. The method according to claim 3, characterized in that the current iteration output power is obtained according to the last iteration output power and the current iteration correction value, specifically including: Add the last iteration output power and the current iteration correction value to obtain the initial output power of the current iteration; Filter the initial output power of the current iteration to obtain the current iteration output power. 5. The method according to claim 1, characterized in that, until a preset condition is met, the current iteration output power is used as the control laser power, specifically including: Until the iteration temperature error is less than the error preset value or until the number of iterations is greater than the number of preset values; The current iteration output power is used as the control laser power. 6. A laser welding temperature controller based on iteration, characterized by including a receiving module, an iteration module and a laser output module, wherein, The receiving module is used to receive the target temperature curve and real-time temperature, and calculate the iterative temperature error according to the target temperature curve and real-time temperature; The iteration module is used to iterate according to the iteration temperature error and the last iteration output power to obtain the current iteration output power until the preset conditions are met, and the current iteration output power is used as the control laser power; The laser output module is used to output a laser beam according to the controlled laser power, and use the laser beam to perform welding. 7. A laser welding equipment, characterized in that it includes a temperature measurement system, a temperature controller, a laser transmitter, a visualization device and a workbench, the temperature measurement system is connected to the temperature controller and the visualization device, and the The temperature controller is connected to the laser emitter, and the visualization device is also connected to the workbench; The temperature measurement system is used to detect real-time temperature; The temperature controller is used to implement the method described in any one of claims 1-5; The laser emitter is used to form a laser beam according to the output power of the temperature controller; The visualization device is used to display the real-time temperature, iterative temperature error and the output power of each iteration; The workbench is used to place welding materials. 8. The laser welding equipment according to claim 7, wherein the temperature measurement system includes an image acquisition module and an image processing module; The image acquisition module is used to acquire the temperature image of the welding object; The image processing module is used to obtain real-time temperature from the temperature image. 9. An electronic device, characterized in that the electronic device includes a memory and a processor, the memory stores a computer program, and when the processor executes the computer program, it implements any one of claims 1-5. Methods. 10. A computer-readable storage medium, characterized in that a processor-executable program is stored therein, and the processor-executable program, when executed by the processor, is used to perform any one of claims 1-5 the method described.