A robotic welding clamp auxiliary system

Abstract

This invention discloses a robotic welding clamp auxiliary system, comprising: a database; a data acquisition unit connected to a robot controller to acquire electrode cap parameter sets in real time, each set of electrode cap parameter sets including a first milling signal, a second milling signal, an electrode cap measurement signal, the number of milling revolutions per cycle, the electrode cap wear amount, and the electrode cap zero-point deviation value, the data acquisition unit sending the electrode cap parameters to the database; an electrode cap evaluation unit connected to the database to obtain the electrode cap parameter sets, and determining the number of electrode cap milling cycles, the electrode cap wear amount corresponding to the number of milling cycles, calculating the difference in electrode cap wear amount corresponding to adjacent milling cycles, and when the difference in electrode cap wear amount is less than a length threshold, the electrode cap evaluation unit outputs a milling abnormality signal; a milling cutter evaluation unit connected to the electrode cap evaluation unit to receive the milling abnormality signal, the milling cutter evaluation unit connected to the database, and determining the milling cutter replacement parameters based on the milling abnormality signal and the cumulative number of milling revolutions.

Description

Technical Field

[0001] This invention relates to the field of robotic welding monitoring technology, and more specifically, to a robotic welding clamp auxiliary system. Background Technology

[0002] Currently, in the machinery manufacturing industry, especially in the automotive body manufacturing field, a white body has about 6,000 welding points, all of which are achieved through resistance welding. Ensuring welding quality is fundamental to welding the body. Robotic automatic servo welding has been used in workshops for more than ten years. The entire welding process involves a large number of equipment and the application is relatively mature, but there are still many problems.

[0003] Firstly, prolonged use of welding clamps can lead to component loosening, resulting in collisions, weld breakage, and weld deformation. Regarding equipment maintenance, a lack of data support makes it difficult to promptly repair or replace welding clamps exhibiting abnormal data changes under the fast-paced automated production environment. Secondly, regarding milling cutter maintenance, milling cutters are frequently used throughout the manufacturing process, and the wear condition of the cutting edges is not visually identifiable, making it impossible to determine the condition of the cutting edges. Replacing cutting edges becomes arbitrary, and during automated robotic milling, the milling quality of the electrodes cannot be accurately assessed. Furthermore, to meet the high pace of daily production, programmer negligence frequently leads to welding problems, such as welding clamps failing to mill after welding thousands of welds, resulting in significant repair costs and a substantial impact on vehicle body quality. Finally, regarding the utilization rate of electrode caps, the lack of precise data to guide their use makes cost control difficult and leads to significant waste on-site. Summary of the Invention

[0004] To address at least one aspect of the aforementioned problems, the present invention provides a robotic welding clamp auxiliary system, comprising: a database; a data acquisition unit connected to a robot controller to acquire electrode cap parameter sets in real time, each set of electrode cap parameters including a first milling signal, a second milling signal, an electrode cap measurement signal, the number of milling revolutions per cycle, electrode cap wear, and electrode cap zero-point deviation; the data acquisition unit sending the electrode cap parameter sets to the database; and an electrode cap evaluation unit connected to the database to obtain the electrode cap parameter sets and evaluate them according to the electrode cap parameters. An array determines the number of times the electrode cap is milled and the corresponding wear amount of the electrode cap. It calculates the wear difference between adjacent milling counts. When the wear difference is less than a length threshold, the electrode cap evaluation unit outputs a milling abnormality signal. A milling cutter evaluation unit, connected to the electrode cap evaluation unit, receives the milling abnormality signal. The milling cutter evaluation unit is connected to the database to receive the number of single milling revolutions of the milling cutter to calculate the cumulative number of milling revolutions. Based on the milling abnormality signal and the cumulative number of milling revolutions, it determines the milling cutter replacement parameters.

[0005] Preferably, the electrode cap evaluation unit further includes a preset number threshold. When the number of times the wear difference of the electrode cap is continuously less than the length threshold is greater than or equal to the number threshold, the electrode cap evaluation unit outputs the milling abnormality signal.

[0006] Preferably, it further includes a resistance measurement unit, which is used to measure the resistance detection value of the electrode cap. When the number of times the wear difference of the electrode cap is less than a preset wear threshold is greater than or equal to the number threshold, it determines whether the resistance detection value is greater than the preset resistance threshold. When the resistance detection value is greater than the resistance threshold, the electrode cap evaluation unit outputs a milling abnormality signal.

[0007] Preferably, the electrode cap evaluation unit further includes setting an electrode cap length threshold, and determining that the electrode cap is usable when the remaining electrode cap is less than the electrode cap length threshold.

[0008] Preferably, when it is determined that the electrode cap is unusable, the total wear amount and total number of milling operations of the electrode cap are obtained, the average milling amount per operation is calculated based on the total wear amount and total number of milling operations of the electrode cap, and the number of times the electrode cap can continue to be milled is determined based on the ideal regrinding length of the electrode cap.

[0009] Preferably, the milling cutter evaluation unit further includes: acquiring the electrode cap wear amount at a first moment; setting a signal quantity threshold, collecting solder joint completion signals, and determining the moment corresponding to when the number of solder joint completion signals is equal to the signal quantity threshold as a second moment; acquiring the electrode cap wear amount at the second moment; and outputting a milling abnormality alarm when the electrode cap wear amount at the first moment is equal to the electrode cap wear amount at the second moment.

[0010] Preferably, it also includes a welding clamp detection unit, which is connected to the database and outputs fault information based on the electrode cap zero-point deviation value stored in the database.

[0011] Preferably, the zero-point deviation value includes a first threshold and a second threshold, wherein the first threshold is less than the second threshold, and an electrode rod fault signal is output when the zero-point deviation value is greater than the first threshold and less than the second threshold, and a welding clamp fault signal is output when the zero-point deviation value is greater than the second threshold.

[0012] The robotic welding gun auxiliary system of this invention has the following beneficial effects: It acquires electrode cap parameters through a data acquisition unit connected to a robot controller; the electrode cap evaluation unit and milling cutter evaluation unit detect abnormal milling shielding and grinding conditions during the welding process, outputting faults in real time for timely maintenance and preventing vehicle body quality issues; it also monitors the electrode cap length to prevent electrode leakage; it monitors changes in the welding gun component dimensions through data monitoring for predictive maintenance; it innovatively implements a method for determining milling cutter replacement parameters by combining milling data with electrode resistance values ​​after each milling operation; it performs real-time calculations and monitoring of milling cutter shielding based on welding information to ensure welding quality; the robotic welding gun auxiliary system operates automatically, serving the welding process and providing a targeted solution to the risks that have always existed in welding workshops. Currently, welding workshops use a large number of automated welding guns with standardized specifications, facilitating the replication and promotion of the robotic welding gun-assisted intelligent manufacturing system. Attached Figure Description

[0013] To better understand the above and other objects, features, advantages, and functions of the present invention, reference can be made to the embodiments shown in the accompanying drawings. The same reference numerals in the drawings refer to the same parts. Those skilled in the art should understand that the drawings are intended to schematically illustrate preferred embodiments of the invention and do not limit the scope of the invention in any way; the parts in the drawings are not drawn to scale.

[0014] Figure 1 A structural block diagram of a robotic welding clamp auxiliary system according to an embodiment of the present invention is shown. Detailed Implementation

[0015] The exemplary embodiments of this disclosure are described below with reference to the accompanying drawings, including various details of the embodiments to aid understanding, and should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this disclosure. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0016] The term "comprising" and its variations as used herein signify open inclusion, i.e., "including but not limited to". Unless otherwise stated, the term "or" means "and / or". The term "based on" means "at least partially based on". The terms "one example embodiment" and "one embodiment" mean "at least one example embodiment". The term "another embodiment" means "at least one additional embodiment". The terms "first", "second", etc., may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0017] To at least partially address one or more of the aforementioned problems and other potential issues, one embodiment of this disclosure proposes a robotic welding clamp assistance system, comprising: a database; a data acquisition unit connected to a robot controller to acquire electrode cap parameter sets in real time, each set of electrode cap parameters including a first milling signal, a second milling signal, an electrode cap measurement signal, the number of milling revolutions per cycle, electrode cap wear, and an electrode cap zero-point deviation value, the data acquisition unit sending the electrode cap parameters to the database; and an electrode cap evaluation unit connected to the database to obtain the electrode cap parameters. The electrode cap parameter set determines the number of electrode cap milling operations and the corresponding electrode cap wear amount based on the parameter set. It also calculates the difference in electrode cap wear amount between adjacent milling operations. When the difference in electrode cap wear amount is less than a length threshold, the electrode cap evaluation unit outputs a milling abnormality signal. The milling cutter evaluation unit is connected to the electrode cap evaluation unit to receive the milling abnormality signal. The milling cutter evaluation unit is connected to the database to receive the number of single milling revolutions of the milling cutter to calculate the cumulative number of milling revolutions. Based on the milling abnormality signal and the cumulative number of milling revolutions, the milling cutter replacement parameters are determined.

[0018] Specifically, such as Figure 1 As shown, the robotic welding gun system includes a robot controller, electrode caps, a welding gun, and a milling cutter. The electrode caps are mounted on the electrode rod of the welding gun. The robot controller controls the welding gun to drive the electrode caps to weld the joints and controls the milling cutter to mill the electrode caps under preset conditions. The robot controller collects parameter information from each device in real time. The first milling signal is the signal emitted during the first milling operation after replacing the new electrode cap. Subsequent milling signals are signals emitted during subsequent milling operations (including the second, third, ..., Nth milling operation, where N is the number of milling operations before replacing the electrode cap). The electrode cap measurement signal is the signal output when measuring the wear of the electrode cap after milling. The number of milling revolutions per operation is the number of rotations of the milling cutter corresponding to each milling operation of the electrode cap. The electrode cap wear is the wear amount of the electrode cap relative to its initial state after the corresponding number of milling operations. The electrode cap zero-point deviation value is the deviation value relative to the defined zero-point coordinates when the electrode cap is zero-point calibrated. The data acquisition unit receives the collected electrode cap parameters through a connection to the robot controller and stores the electrode cap parameters in a database. For example, the database will correspond each parameter in each group of electrode cap parameters. In another embodiment, a display unit is also included. The display unit is connected to the database and displays each parameter of each group of electrode cap parameters through the display unit.

[0019] The electrode cap evaluation unit connects to the database to receive electrode cap parameter sets. It evaluates the parameter sets corresponding to adjacent milling cycles of the same electrode cap. Based on the initial milling signal, the unit determines if a new electrode cap has been replaced and counts the number of milling cycles for the replaced electrode cap. This count is accumulated based on subsequent milling signals to determine the total number of electrode cap milling cycles. Further, the electrode cap wear amount corresponding to the number of milling cycles is determined based on the wear amount corresponding to the milling measurement signal, ensuring a one-to-one correspondence. For example, the electrode cap milling cycle n, the number of milling revolutions m, the electrode cap wear amount l, and the electrode cap zero-point deviation value r represent the following: after the nth milling cycle, the wear amount of the electrode cap relative to its initial length is l; after the nth milling cycle, the milling cutter rotates m revolutions; and the deviation distance of the electrode cap relative to the defined zero-point coordinates is r. The electrode cap parameter sets corresponding to the Nth and N+1th milling operations of the same electrode cap are evaluated. The difference in wear length between the two milling operations is calculated, i.e., the electrode cap wear difference value. The length threshold is set according to the characteristics of the electrode cap and specific usage requirements. When the electrode cap wear difference value is equal to zero, it means that the length of the electrode cap has not changed after the two milling operations, and the milling is invalid. When the electrode cap wear difference value is greater than zero and less than the preset length threshold, it means that the change in the length of the electrode cap after the second milling operation does not meet the accuracy requirements, and it is a non-compliant milling operation. The electrode cap evaluation unit outputs milling abnormality signals for invalid and non-compliant milling operations.

[0020] The milling cutter evaluation unit receives milling anomaly signals via a connection to the electrode cap evaluation unit. Based on these signals, it connects to a database to receive single-cycle milling parameters from the electrode cap parameter group. It should be noted that the data acquisition unit also acquires milling cutter replacement signals via the robot controller and stores them in a database. This database also includes a milling cutter data unit that receives the milling cutter replacement signals and the number of single-cycle milling revolutions from the electrode cap parameter group to calculate the cumulative number of milling revolutions. After replacing the milling cutter, the cumulative number of milling revolutions is reset to zero, and the cumulative number of milling revolutions for the replaced milling cutter is recalculated. The milling cutter evaluation unit determines the milling cutter replacement parameters based on the cumulative number of milling revolutions and the milling anomaly signals. For example, in some embodiments, the milling cutter evaluation unit collects the cumulative number of milling revolutions for multiple milling cutters when they receive milling anomaly signals; the replacement parameters are the average of the cumulative number of milling revolutions for multiple milling cutters.

[0021] In some embodiments, the milling cutter evaluation unit is connected to the display unit, which displays the cumulative number of milling revolutions of the milling cutter and milling abnormality signals to prompt for cutter replacement. It monitors whether each electrode cap milling operation is satisfactory, outputs calculation results in real time, and provides a clear overview of the milling process by displaying the entire lifespan of the electrode cap's milling data.

[0022] In some embodiments, the electrode cap evaluation unit further includes a preset number threshold. When the number of times the electrode cap wear difference is continuously less than the length threshold is greater than or equal to the number threshold, the electrode cap evaluation unit outputs a milling abnormality signal.

[0023] Specifically, the electrode cap evaluation unit further filters the results of judging the difference in electrode cap wear amount using a number of threshold tests. For example, when the difference in electrode cap wear amount is less than the length threshold four times consecutively, a milling abnormality signal is output. This is to avoid outputting a milling abnormality signal due to measurement errors or insufficient measurement accuracy of the electrode cap wear amount. The number of threshold tests can also be three, five, or six times, etc., depending on the measurement accuracy and welding specifications of the robotic welding gun.

[0024] In some embodiments, a resistance measurement unit is further included. The resistance measurement unit is used to measure and obtain the resistance detection value of the electrode cap. When the number of times the wear difference of the electrode cap is less than a preset wear threshold is greater than or equal to the number threshold, it is determined whether the resistance detection value is greater than the preset resistance threshold. When the resistance detection value is greater than the resistance threshold, the electrode cap evaluation unit outputs a milling abnormality signal.

[0025] Specifically, the resistance measurement unit employs a resistance detection circuit connected to the electrode cap evaluation unit. It determines the normal operating status of the electrode cap by collecting the resistance detection value. When the resistance detection value is less than or equal to a resistance threshold, the electrode cap is operating normally; when the resistance detection value is greater than the resistance threshold, the electrode cap is operating abnormally. The electrode cap evaluation unit evaluates the electrode cap status based on the resistance detection value. When the number of times the electrode cap wear difference is continuously less than a preset wear threshold is greater than or equal to a threshold value, and the resistance detection value is greater than the resistance threshold, it is determined that the milling process has affected the electrode cap's operating status, and a milling abnormality signal is output. When the number of times the electrode cap wear difference is continuously less than the preset wear threshold is greater than or equal to the threshold value, and the resistance detection value is less than or equal to the resistance threshold, it is determined that the electrode cap's operating status has not been affected by milling, and no milling abnormality signal is output.

[0026] In some embodiments, the electrode cap evaluation unit further includes setting an electrode cap length threshold, and determining that the electrode cap is usable when the remaining length of the electrode cap is less than the electrode cap length threshold.

[0027] Specifically, the electrode cap evaluation unit is also used to monitor the status of the electrode cap. The electrode cap length threshold is a set effective reference length that the electrode cap can still be used normally after being worn to this length. In order to avoid the electrode cap being worn through and leaking liquid during use, an alarm prompt is output when the wear of the electrode cap is greater than the electrode cap length threshold so that the electrode cap can be replaced in time.

[0028] In some embodiments, when it is determined that the electrode cap is unusable, the total wear amount and total number of milling operations of the electrode cap are obtained, the average milling amount per operation is calculated based on the total wear amount and total number of milling operations of the electrode cap, and the number of further milling operations of the electrode cap is determined based on the ideal over-grinding length of the electrode cap.

[0029] Specifically, when the electrode wear is greater than or equal to the electrode cap length threshold, the total wear and total number of milling operations are calculated based on the electrode cap parameter set. The average milling amount per milling operation is then calculated. Since the ideal length of the electrode cap is less than the effective reference length, the number of further milling operations is determined by calculating the difference between the ideal regrinding length and the effective reference length, combined with the average milling amount. The effective number of milling operations is determined by the sum of the possible further milling operations and the total number of milling operations. The electrode cap parameter set data is monitored based on the effective number of milling operations. Verification is performed to achieve the ideal milling length, and the milling amount is corrected based on the verification results.

[0030] In the use of welding clamps, electrode caps and milling cutters are the two major consumables. The economic evaluation of electrode cap use provides data basis for electrode cap use. The system calculates the usable space after the electrode cap is replaced in real time. The calculation results can directly guide the robot controller parameter changes, improve utilization rate, and reduce production costs. At the same time, the system performs real-time size judgment on the welding electrode cap, eliminating the phenomenon of electrode cap milling leakage caused by parameter changes during operation, and eliminating welding quality problems.

[0031] In some embodiments, the milling cutter evaluation unit further includes: acquiring the electrode cap wear amount at a first moment; setting a signal quantity threshold, acquiring solder joint completion signals, and determining the moment corresponding to when the number of solder joint completion signals equals the signal quantity threshold as a second moment; acquiring the electrode cap wear amount at the second moment; and outputting a milling abnormality alarm when the electrode cap wear amount at the first moment equals the electrode cap wear amount at the second moment.

[0032] Specifically, the robot controller collects the solder joint completion signal and stores it in the database through the data acquisition unit. The milling cutter evaluation unit also includes a shielding detection module, which connects to the database to receive solder joint completion signals in real time. The shielding detection module can be started by receiving a start command, which is input by the user through the input unit. The start time of the shielding detection module is the first moment, and it begins counting solder joint completion signals. When the number of solder joint completion signals reaches a threshold (e.g., 500), it is determined to be the second moment. The wear amount of the electrode cap at the first moment and the second moment is compared. When the wear amount of the electrode cap at the first moment is equal to the wear amount of the electrode cap at the second moment, it is determined that the electrode cap has not been milled by the milling cutter, that is, the milling cutter is shielded, and a milling abnormality signal is output.

[0033] The shielding detection module ensures that the welding electrode cap is continuously polished during the welding process, ensuring that the heat is concentrated on the plate material and guaranteeing the welding quality. At the same time, it can detect whether the milling data is abnormal during the operation of the robotic welding gun, and whether there is any artificial shielding during the milling process, preventing equipment damage and welding defects from being discharged, which would lead to huge rework costs.

[0034] In some embodiments, a welding clamp detection unit is also included. This unit is connected to a database and outputs fault information based on the zero-point deviation values ​​of the electrode cap stored in the database. Specifically, the zero-point deviation values ​​include a first threshold (e.g., 1 mm) and a second threshold (e.g., 2 mm). The first threshold is less than the second threshold. When the zero-point deviation value is greater than the first threshold but less than the second threshold, an electrode rod fault signal is output; when the zero-point deviation is greater than the second threshold, a welding clamp fault signal is output. Electrode rod faults include electrode rod loosening, electrode rod wear, and electrode rod angle deviation; welding clamp faults include loose screws in the welding clamp body structure and loose screws in the main cylinder.

[0035] The welding gun inspection unit can effectively detect the welding reference point of the robot welding gun, monitor the changes in the distance between the welding point trajectory and the vehicle body during the welding process, prevent vehicle body collisions caused by welding point defects and loose welding gun components, promptly improve the maintenance of the welding gun components themselves, detect equipment problems early, and reduce costs.

[0036] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand this document.

Claims

1. A robotic welding gun auxiliary system, characterized in that, include: database; The data acquisition unit is connected to the robot controller to acquire electrode cap parameter sets in real time. Each set of electrode cap parameter sets includes the first milling signal, the second milling signal, the electrode cap measurement signal, the number of milling revolutions in a single cycle, the electrode cap wear amount, and the electrode cap zero point deviation value. The data acquisition unit sends the electrode cap parameter sets to the database. The electrode cap measurement signal is the signal output when measuring the electrode cap wear amount after milling. An electrode cap evaluation unit connects to the database to obtain the electrode cap parameter set. Based on the electrode cap parameter set, it determines the number of milling operations and the corresponding wear amount of the electrode cap. It calculates the wear amount difference between adjacent milling operations. When the wear amount difference is less than a length threshold, the electrode cap evaluation unit outputs a milling abnormality signal. When the wear amount difference is zero, it indicates that the length of the electrode cap has not changed after two milling operations, and the milling is invalid. When the wear amount difference is greater than zero and less than a preset length threshold, it indicates that the change in electrode cap length after the subsequent milling does not meet the accuracy requirements, and the milling is unqualified. The electrode cap evaluation unit outputs milling abnormality signals for invalid and unqualified milling operations. The milling cutter evaluation unit is connected to the electrode cap evaluation unit to receive the milling abnormality signal. The milling cutter evaluation unit is connected to the database to receive the number of single milling revolutions of the milling cutter to calculate the cumulative number of milling revolutions of the milling cutter. Based on the milling abnormality signal and the cumulative number of milling revolutions, the replacement parameters of the milling cutter are determined. The milling cutter evaluation unit collects the cumulative number of milling revolutions of multiple milling cutters when they receive the milling abnormality signal. The replacement parameters are the average of the cumulative number of milling revolutions of multiple milling cutters.

2. The system according to claim 1, characterized in that, The electrode cap evaluation unit also includes a preset number threshold. When the number of times the wear difference of the electrode cap is continuously less than the length threshold is greater than or equal to the number threshold, the electrode cap evaluation unit outputs the milling abnormality signal.

3. The system according to claim 2, characterized in that, It also includes a resistance measurement unit, which is used to measure the resistance detection value of the electrode cap. When the number of times the wear difference of the electrode cap is less than a preset wear threshold is greater than or equal to the number threshold, it is determined whether the resistance detection value is greater than the preset resistance threshold. When the resistance detection value is greater than the resistance threshold, the electrode cap evaluation unit outputs a milling abnormality signal.

4. The system according to claim 3, characterized in that, The electrode cap evaluation unit also includes setting an electrode cap length threshold. When the wear length of the electrode cap is less than the electrode cap length threshold, the electrode cap is determined to be usable.

5. The system according to claim 4, characterized in that, When the electrode cap is determined to be unusable, the total wear amount and total number of milling operations of the electrode cap are obtained. The average milling amount per operation is calculated based on the total wear amount and total number of milling operations of the electrode cap. The number of times the electrode cap can continue to be milled is determined based on the ideal regrinding length.

6. The system according to claim 4, characterized in that, The milling cutter evaluation unit also includes: Obtain the electrode cap wear at the first moment; Set a signal quantity threshold, collect solder joint completion signals, and determine the time when the number of solder joint completion signals equals the signal quantity threshold as the second time. Obtain the electrode cap wear amount at the second time point; When the wear of the electrode cap at the first moment is equal to the wear of the electrode cap at the second moment, a milling abnormality alarm is output.

7. The system according to claim 1, characterized in that, It also includes a welding clamp detection unit, which is connected to the database and outputs fault information based on the electrode cap zero-point deviation value stored in the database.

8. The system according to claim 7, characterized in that, The zero-point deviation value includes a first threshold and a second threshold. The first threshold is less than the second threshold. When the zero-point deviation value is greater than the first threshold and less than the second threshold, an electrode rod fault signal is output. When the zero-point deviation value is greater than the second threshold, a welding clamp fault signal is output.

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