Welding compensation control system based on temperature change

Abstract

The present invention relates to the field of welding technology, and in particular to a welding compensation control system based on temperature changes. The compensation is divided into two stages. One is to determine the initial welding current according to the ambient temperature or the temperature of a workpiece to be welded before welding; the other is to adjust the welding current in real time according to the temperature change of the workpiece to be welded during the welding process. For occasions where the welding effect is greatly affected by temperature, such as occasions where the temperature difference between day and night is large and the welding state is sensitive to current fluctuations, the welding current is automatically adjusted according to the temperature change, thereby reducing the influence of temperature changes on the welding effect.

Description

Technical Field

[0001] The invention relates to the technical field of welding, and in particular to a welding compensation control system based on temperature change. Background Art

[0002] With the development of automatic welding technology, the welding field has gradually gotten rid of the situation of being completely dependent on manual labor. In order to improve welding efficiency and welding quality, companies are increasingly using automatic welding equipment, such as special welding machines and welding robots.

[0003] Automatic welding often requires the design of welding specifications in advance. In the batch production process, human intervention in the operation of the machine is rare. However, the quality of welding depends not only on the current, voltage and other factors of the automatic welding equipment itself, but is also easily affected by the ambient temperature, especially the welding of aluminum materials is greatly affected by the ambient temperature; the ambient temperature difference varies greatly during the day, and the welding specifications in the early morning are often not applicable to noon; therefore, the aluminum welding workshop often installs air conditioners to adjust the temperature and reduce temperature fluctuations; however, since the workshop space is usually large, multiple air conditioners need to be installed in the workshop, and the energy consumption of each air conditioner is high, which increases the production cost. Summary of the invention

[0004] In view of the above problems, an embodiment of the present invention provides a welding compensation control system based on temperature change.

[0005] In one aspect of the present invention, a welding compensation control system based on temperature change is provided, comprising a host computer, automatic welding equipment and a temperature sensor;

[0006] Before welding, the temperature sensor detects the temperature of the workpiece to be welded or the ambient temperature as the pre-welding temperature, and sends the pre-welding temperature to the host computer;

[0007] After receiving the pre-welding temperature, the host computer searches for the welding specification according to the pre-welding temperature, obtains the initial current for welding the workpiece to be welded, and sends the initial current to the automatic welding equipment;

[0008] After receiving the initial current, the automatic welding equipment adjusts the current according to the initial current and starts welding the workpiece to be welded;

[0009] During the welding process, the temperature sensor detects the temperature of the workpiece to be welded in real time as the welding temperature, and sends the welding temperature to the host computer;

[0010] After receiving the welding temperature, the host computer determines the temperature change value of the workpiece to be welded during the welding process, determines the adjusted welding current based on the negative correlation principle between the welding current and the temperature change value, and sends the adjusted welding current to the automatic welding equipment;

[0011] After receiving the adjusted welding current, the automatic welding equipment adjusts the current according to the adjusted welding current and continues to weld the workpiece to be welded.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: the compensation is divided into two stages: one is to determine the initial welding current according to the ambient temperature or the temperature of the workpiece to be welded before welding; the other is to adjust the welding current in real time according to the temperature change of the workpiece to be welded during the welding process. For occasions where the welding effect is greatly affected by temperature, such as the large temperature difference between day and night and the welding state is sensitive to current fluctuations, the welding current can be automatically adjusted according to the temperature change, thereby reducing the influence of temperature change on the welding effect.

[0013] Optionally, the process of determining the adjusted welding current based on the negative correlation principle between the welding current and the temperature change value includes:

[0014] The adjusted welding current is determined using the following expression:

[0015] I 1 =I 0 +k(T 1 -T 0 )

[0016] Among them, I 1 Indicates the adjusted welding current, I 0 Indicates the welding current corresponding to the previous detection cycle, k indicates that the predetermined coefficient is a negative value, T 1 Indicates the welding temperature detected in the current detection cycle, T 0 Indicates the welding temperature detected in the previous detection cycle.

[0017] Optionally, the temperature sensor is a contact temperature sensor, and a contact temperature sensor is arranged near each weld on the workpiece to be welded;

[0018] Before welding, the automatic welding equipment identifies the number and position of welds on the workpiece to be welded and the position of the contact temperature sensor near each weld, and assigns an identifier to each weld and the contact temperature sensor near the weld, and sends the assigned identifier to the host computer;

[0019] When welding starts, the automatic welding equipment sends the identification of the weld to be welded to the host computer. After receiving the identification, the host computer determines that the target contact temperature sensor corresponding to the identification is valid based on the received identification, and adjusts the welding current during the welding process using the welding temperature detected by the determined target contact temperature sensor.

[0020] Optionally, the temperature sensor is an infrared temperature sensor, a multi-axis moving platform is arranged around the automatic welding equipment, and the infrared temperature sensor is arranged on the multi-axis moving platform;

[0021] Before welding, the automatic welding equipment identifies the number and location of welds on the workpiece to be welded;

[0022] When welding starts, the automatic welding equipment determines the position of the weld to be welded and the position of the infrared temperature sensor, and simultaneously moves the infrared temperature sensor to the vicinity of the weld to be welded through a multi-axis moving platform.

[0023] Optionally, there are multiple infrared temperature sensors;

[0024] Before welding, the automatic welding equipment assigns an identifier to each infrared temperature sensor and sends the assigned identifier to the host computer;

[0025] When welding starts, the automatic welding equipment determines the position of the weld to be welded and selects an infrared temperature sensor that can be moved to the position closest to the weld as the target infrared temperature sensor, moves the target infrared temperature sensor to the vicinity of the weld to be welded through a multi-axis mobile platform, and sends the identification of the target infrared temperature sensor to the host computer;

[0026] After receiving the identification, the host computer determines that the corresponding target infrared temperature sensor is valid based on the received identification, and adjusts the welding current during the welding process using the welding temperature detected by the target infrared temperature sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings described herein are used to provide a further understanding of the present invention, constitute a part of the present application, and do not constitute a limitation of the present invention. In the drawings:

[0028] Figure 1 A schematic diagram of a compensation process of a welding compensation control system based on temperature change provided by an embodiment of the present invention;

[0029] Figure 2 A schematic diagram of the arrangement position of a contact temperature sensor provided in an embodiment of the present invention;

[0030] Figure 3 A schematic diagram of the arrangement position of an infrared temperature sensor provided by an embodiment of the present invention

[0031] Figure 4 A schematic diagram of an infrared temperature sensor installation structure provided by an embodiment of the present invention Figure 1 ;

[0032] Figure 5A schematic diagram of an infrared temperature sensor installation structure provided by an embodiment of the present invention Figure 2 . DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments and the accompanying drawings. Here, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0034] See also Figure 1 , the welding compensation control system based on temperature change provided by the present invention includes a host computer, automatic welding equipment and a temperature sensor;

[0035] Before welding, the temperature sensor detects the temperature of the workpiece to be welded or the ambient temperature as the pre-welding temperature, and sends the pre-welding temperature to the host computer;

[0036] After receiving the pre-welding temperature, the host computer searches for the welding specification according to the pre-welding temperature, obtains the initial current for welding the workpiece to be welded, and sends the initial current to the automatic welding equipment;

[0037] After receiving the initial current, the automatic welding equipment adjusts the current according to the initial current and starts welding the workpiece to be welded;

[0038] During the welding process, the temperature sensor detects the temperature of the workpiece to be welded in real time as the welding temperature, and sends the welding temperature to the host computer;

[0039] After receiving the welding temperature, the host computer determines the temperature change value of the workpiece to be welded during the welding process, determines the adjusted welding current based on the negative correlation principle between the welding current and the temperature change value, and sends the adjusted welding current to the automatic welding equipment;

[0040] After receiving the adjusted welding current, the automatic welding equipment adjusts the current according to the adjusted welding current and continues to weld the workpiece to be welded.

[0041] During implementation, automatic welding equipment includes but is not limited to welding robots, special welding machines, etc.; temperature sensors include but are not limited to ordinary temperature and humidity sensors, infrared temperature sensors, thermocouples and other temperature sensors; host computers include but are not limited to industrial computers, PLCs, IOT units, mobile terminals, etc.; the host computer serves as a control center to read temperature sensor detection information and transmit current compensation values ​​to automatic welding equipment; the communication method between the host computer and the temperature sensor and automatic welding equipment can be Modbus / TCP, Modbus / RTU, etc.

[0042] Compensation is divided into two stages: one is compensation before welding, and the other is compensation during welding; Compensation before welding: After the temperature sensor detects the temperature of the workpiece to be welded or the ambient temperature, the host computer can determine the initial welding current by looking up the welding specification. The welding specification is the specification corresponding to different initial currents at different temperatures set in advance according to the characteristics of the workpiece to be welded, which can be stored in the host computer in advance;

[0043] Compensation in welding: Since the temperature of the workpiece will gradually increase during the welding process, the initial current at the starting point of welding may not be suitable for subsequent welding conditions. Therefore, the welding current can be automatically adjusted according to the temperature change of the workpiece during the welding process. During the adjustment process, the welding current is negatively correlated with the temperature change value. The specific calculation formula is as follows:

[0044] I 1 =I 0 +k(T 1 -T 0 )

[0045] Among them, I 1 Indicates the adjusted welding current, I 0 Indicates the welding current corresponding to the previous detection cycle, k indicates that the predetermined coefficient is a negative value, which can be -0.5, T 1 Indicates the welding temperature detected in the current detection cycle, T 0 Indicates the welding temperature detected in the previous detection cycle; the detection cycle is the interval between two adjacent detections, which can be set as needed. For example, when the detection cycle is 1 second, the temperature of the workpiece to be welded is detected every 1 second and the welding current is adjusted according to the temperature change.

[0046] In implementation, the temperature sensor may be a contact temperature sensor, and when there are many weld positions and the temperature of a certain weld cannot represent the temperature of the next weld position, a contact temperature sensor may be provided for each weld, such as Figure 2As shown, there are four welds on the workpiece 1, which are counted as the first weld 2, the second weld 3, the third weld 4 and the fourth weld 5 respectively. Correspondingly, each weld corresponds to a contact temperature sensor, which are counted as the first contact temperature sensor 6, the second contact temperature sensor 7, the third contact temperature sensor 8 and the fourth contact temperature sensor 9 respectively. The vertical distance between the contact temperature sensor and the weld is not more than 20 cm. In order to distinguish each weld and the detection value of which contact temperature sensor is used when each weld is welded, before welding, the automatic welding equipment can identify the number and position of welds on the workpiece to be welded and the position of the contact temperature sensor near each weld, and assign a unified identification to each weld and the contact temperature sensor near the weld, such as assigning identification GI=1, indicating the identification of the first weld 2 and its corresponding first contact sensor 6, and sending the assigned identification to the host computer at the same time, and the host computer corresponds each identification to each contact temperature sensor one by one;

[0047] Correspondingly, at the beginning of welding, the automatic welding equipment sends the identification of the weld to be welded to the host computer. After receiving the identification, the host computer determines that the corresponding target contact temperature sensor is valid based on the received identification, and adjusts the welding current during the welding process using the welding temperature detected by the determined target contact temperature sensor. For example, at the beginning of welding, the automatic welding equipment sends GI=1 to the host computer, and the host computer can determine that the first weld 2 is about to be welded, and use the detection value of the first contact temperature sensor 6 to adjust the welding current; after the welding of the first weld 2 is completed, the automatic welding equipment sends the identification of the next weld to the host computer according to the welding process. After receiving the identification, the host computer can determine that it is necessary to switch to the corresponding sensor to adjust the welding current.

[0048] In practice, the temperature sensor may also be a non-contact infrared temperature sensor. When setting, a multi-axis mobile platform 11 is set around the automatic welding equipment 10, and the infrared temperature sensor 12 is set on the multi-axis mobile platform 11. Figure 3 As shown, a moving track of the multi-axis moving platform 11 can be set above the automatic welding equipment 10, and the multi-axis moving platform 11 can change its position around the automatic welding equipment 10 through the moving track. When setting, the infrared temperature sensor 12 can be installed by rotating the swing arm set on the multi-axis moving platform 11 at the bottom, and the infrared temperature sensor 12 can rotate and swing with the swing arm. The specific driving structure can adopt a conventional structure and will not be repeated here;

[0049] Before welding, the automatic welding equipment identifies the number and location of welds on the workpiece to be welded;

[0050] When welding starts, the automatic welding equipment determines the position of the weld to be welded and the position of the infrared temperature sensor, and at the same time moves the infrared temperature sensor to the vicinity of the weld to be welded through a multi-axis mobile platform to detect the temperature change at the weld position during the welding process; at the same time, during the welding process, the infrared temperature sensor can be controlled in real time through the multi-axis mobile platform to move along with the welding torch of the automatic welding equipment.

[0051] In order to prevent the situation that a single infrared temperature sensor may have a blind spot or the infrared temperature sensor fails to detect, multiple infrared temperature sensors can be selected. Before welding, the automatic welding equipment assigns an identifier to each infrared temperature sensor and sends the assigned identifier to the host computer. The host computer matches each identifier to each infrared temperature sensor one by one.

[0052] When welding starts, the automatic welding equipment determines the position of the weld to be welded and selects an infrared temperature sensor that can be moved to the position closest to the weld as the target infrared temperature sensor. For example, a plane coordinate system can be established according to the distribution of the moving track, and the coordinates of the weld and the coordinates of each infrared temperature sensor can be determined in the plane coordinate system. In combination with the moving tracks of each multi-axis moving platform on the moving track, an infrared temperature sensor that can be moved to the position of the weld is selected as the target infrared temperature sensor. For example, an infrared temperature sensor with the shortest moving distance when moving to the above-mentioned closest position is selected, and the target infrared temperature sensor is moved to the vicinity of the weld to be welded by the multi-axis moving platform, and the identification of the target infrared temperature sensor is sent to the host computer at the same time;

[0053] After receiving the identification, the host computer determines that the corresponding target infrared temperature sensor is valid based on the received identification, and adjusts the welding current during the welding process using the welding temperature detected by the target infrared temperature sensor.

[0054] During implementation, two target infrared temperature sensors can also be selected to simultaneously detect the temperature of the weld position. The two target infrared temperature sensors are located at different positions of the moving track and detect the temperature of the weld position at the same time. The corresponding host computer can use the temperature values ​​detected by the two target infrared temperature sensors to adjust the welding current, such as taking the average value of the temperature values ​​detected by the two target infrared temperature sensors as the basis for adjusting the welding current.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A welding compensation control system based on temperature change, comprising a host computer, automatic welding equipment and a temperature sensor; characterized in that: Before welding, the temperature sensor detects the temperature of the workpiece to be welded or the ambient temperature as the pre-welding temperature, and sends the pre-welding temperature to the host computer; After receiving the pre-welding temperature, the host computer searches for the welding specification according to the pre-welding temperature, obtains the initial current for welding the workpiece to be welded, and sends the initial current to the automatic welding equipment; After receiving the initial current, the automatic welding equipment adjusts the current according to the initial current and starts welding the workpiece to be welded; During the welding process, the temperature sensor detects the temperature of the workpiece to be welded in real time as the welding temperature, and sends the welding temperature to the host computer; After receiving the welding temperature, the host computer determines the temperature change value of the workpiece to be welded during the welding process, determines the adjusted welding current based on the negative correlation principle between the welding current and the temperature change value, and sends the adjusted welding current to the automatic welding equipment; After receiving the adjusted welding current, the automatic welding equipment adjusts the current according to the adjusted welding current and continues to weld the workpiece to be welded; The temperature sensor adopts an infrared temperature sensor. A multi-axis mobile platform is arranged around the automatic welding equipment, and the infrared temperature sensor is arranged on the multi-axis mobile platform. Before welding, the automatic welding equipment identifies the number and position of the welds on the workpiece to be welded. When welding starts, the automatic welding equipment determines the position of the weld to be welded and the position of the infrared temperature sensor, and moves the infrared temperature sensor to the vicinity of the weld to be welded through the multi-axis mobile platform. In order to prevent the situation that a single infrared temperature sensor may have a detection blind spot or the infrared temperature sensor fails to detect, the number of infrared temperature sensors is multiple. Before welding, the automatic welding equipment is Each infrared temperature sensor is assigned an identifier, and the assigned identifier is sent to the host computer; when welding starts, the automatic welding equipment determines the position of the weld to be welded and selects an infrared temperature sensor that can be moved to the position closest to the weld as the target infrared temperature sensor, and moves the target infrared temperature sensor to the vicinity of the weld to be welded through a multi-axis mobile platform, and sends the identifier of the target infrared temperature sensor to the host computer; after receiving the identifier, the host computer determines that the corresponding target infrared temperature sensor is valid based on the received identifier, and adjusts the welding current using the welding temperature detected by the target infrared temperature sensor during the welding process; Alternatively, the temperature sensor adopts a contact temperature sensor, and a contact temperature sensor is arranged near each weld on the workpiece to be welded; before welding, the automatic welding equipment identifies the number and position of the welds on the workpiece to be welded and the position of the contact temperature sensor near each weld, and assigns an identifier to each weld and the contact temperature sensor near the weld, and sends the assigned identifier to the host computer; when welding starts, the automatic welding equipment sends the identifier of the weld to be welded to the host computer, and after receiving the identifier, the host computer determines that the target contact temperature sensor corresponding to the identifier is valid based on the received identifier, and adjusts the welding current during the welding process using the welding temperature detected by the determined target contact temperature sensor.

2. The welding compensation control system based on temperature change according to claim 1, characterized in that: The process of determining the adjusted welding current based on the negative correlation between the welding current and the temperature change value includes: The adjusted welding current is determined using the following expression: Among them, I1 represents the adjusted welding current, I0 represents the welding current corresponding to the previous detection cycle, k represents that the predetermined coefficient is a negative value, T1 represents the welding temperature detected in the current detection cycle, and T0 represents the welding temperature detected in the previous detection cycle.

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