Micro-resistance spot welding large cantilever electrode displacement signal multi-sensing measurement method and system

Abstract

The application provides a micro-resistance spot welding large cantilever electrode displacement signal multi-sensing measurement method and system, comprising the following steps: S1, collecting sensor data in the air pressure process, and calibrating the rigidity of the electrode pressurizing mechanism; S2, performing sample welding, and collecting dynamic signals in the welding process; S3, according to the rigidity of the electrode pressurizing mechanism, coupling the pressure signal, the displacement signal and the acceleration signal to obtain a far-end displacement signal and a near-end vibration signal; and S4, using the near-end vibration signal to perform vibration filtering on the far-end displacement signal to obtain a smooth electrode displacement signal, and completing the measurement process. The application avoids the sensor installation interference problem that occurs when the electrode displacement signal is measured in the near-end welding area, can on-line monitor the micro-spot welding process without interfering with the welding process, eliminates the signal jitter problem caused by the insufficient rigidity of the large cantilever electrode pressurizing mechanism, and improves the accuracy of the far-end measured displacement signal.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of micro resistance spot welding, in particular to a multi-sensor measurement method and system for large cantilever electrode displacement signal of micro resistance spot welding. BACKGROUND

[0002] Micro resistance spot welding technology is widely used in the manufacturing process of battery packaging, medical devices, electronic devices, etc. With the development of intelligent technology, the quality of micro resistance spot welding is continuously improved. The micro resistance spot welding workpiece is thin and small in size, and there has been a lack of reliable quality online detection means.

[0003] When detecting the quality of the welding spot manually, it is easy to cause fatigue due to continuous work, and it is easy to cause missed detection. In order to replace manual detection, in the field of traditional resistance spot welding, welding process sensing signals are widely used for online detection of welding spot quality. Among them, the electrode displacement signal has strong correlation with the welding spot quality, and therefore has been widely concerned. However, in the field of micro resistance spot welding, due to the reduction of the size of the workpiece, the amplitude of the electrode displacement signal is reduced to about 10% of that of traditional spot welding, making the signal more susceptible to noise caused by mechanism vibration. In addition, in order to increase the operation space, large cantilever structures are often used in production sites, which will produce larger mechanism vibration amplitude, further increasing the difficulty of electrode displacement signal measurement. Measuring the displacement signal near the electrode can ensure the measurement accuracy, but will cause mechanism interference and higher measurement cost, seriously affecting the welding production process; and the traditional far-end measurement method of electrode displacement signal does not consider vibration filtering, which will cause large measurement error when applied in the field of micro resistance spot welding, limiting the research and application of online quality detection in the field of micro resistance spot welding. SUMMARY

[0004] In view of the defects in the prior art, the purpose of the present application is to provide a multi-sensor measurement method and system for large cantilever electrode displacement signal of micro resistance spot welding.

[0005] According to the multi-sensor measurement method for large cantilever electrode displacement signal of micro resistance spot welding provided by the present application, the method comprises the following steps:

[0006] Step S1: Collect sensor data during air pressure process, and calibrate electrode pressurizing mechanism stiffness;

[0007] Step S2: Perform sample welding, and collect dynamic signals during welding process;

[0008] The dynamic signals include acceleration signals, pressure signals and displacement signals;

[0009] Step S3: According to the electrode pressurizing mechanism stiffness, the acceleration signals, the pressure signals and the displacement signals are coupled to obtain far-end displacement signals and near-end vibration signals;

[0010] Step S4: using the proximal vibration signal to vibration filter the distal displacement signal, obtaining the filtered electrode displacement signal, completing the measurement process.

[0011] Preferably, the sensor includes some or all of the upper electrode acceleration sensor, the upper electrode pressure sensor, the upper electrode displacement sensor, the lower electrode acceleration sensor, the lower electrode pressure sensor, and the lower electrode displacement sensor; the step S1 includes setting multiple electrode pressure levels for air pressure, collecting and recording the acceleration signal and the pressure signal during the air pressure process, and simultaneously measuring the displacement of the electrode end; the electrode pressurizing mechanism stiffness is calibrated according to the following formula:

[0012] v i (t)=∫a i (t)dt;

[0013] F i (t)=k·S i (t)+ξ·v i (t)+m·a i (t)

[0014] wherein, F i (t) and a i (t) are the pressure signal and the acceleration signal during the air pressure stage at different set pressure levels; S i (t) is the measured electrode end displacement signal during the air pressure stage at different set pressure levels; v i (t) is the speed signal of the electrode end, which is obtained by integrating the acceleration signal; i=1, 2, 3, …, n, representing the air pressure stage at different electrode pressure levels; k, ξ and m are the electrode pressurizing mechanism stiffness coefficients to be calibrated;

[0015] Preferably, the step S3 includes:

[0016] The distal displacement signal S r is calculated according to the following formula:

[0017] S r =f1(F,S,a)

[0018] wherein, F is the pressure signal collected by the pressure sensor, S is the displacement signal collected by the displacement sensor, a is the acceleration signal collected by the acceleration sensor, and f1 is the distal displacement signal operation processing process, and the pressure signal, the displacement signal and the acceleration signal are coupled to obtain the distal displacement signal S r through the distal displacement signal operation processing process f1(·).

[0019] The proximal vibration signal S v is calculated according to the following formula:

[0020] S v= f2(a)

[0021] wherein f2 is a proximal vibration signal operation process, the acceleration signal is processed by the proximal vibration signal operation process f2(·) to obtain a proximal vibration signal S v .

[0022] Preferably, the step S4 includes eliminating the influence of the proximal vibration signal in the distal displacement signal, and the processed signal is taken as a filtered electrode displacement signal, and:

[0023] S e = f3(S r ,S v );

[0024] wherein S e represents the filtered electrode displacement signal, f3 is a vibration filtering operation process, the distal displacement signal and the proximal vibration signal are processed by the vibration filtering operation process f3(·) to obtain the electrode displacement signal S e .

[0025] When different sensors are used for operation, the forms of the operation processes f1, f2 and f3 change.

[0026] According to the micro-resistance spot welding large cantilever electrode displacement signal multi-sensor measurement system provided by the application, the following modules are included, but not limited to, part or all of the following modules:

[0027] the upper electrode, the lower electrode, the upper electrode cantilever, the lower electrode cantilever, the upper electrode acceleration sensor, the upper electrode pressure sensor, the upper electrode displacement sensor, the lower electrode acceleration sensor, the lower electrode pressure sensor, the lower electrode displacement sensor, the rack, the dynamic signal acquisition module, and the calculation analysis module.

[0028] The upper electrode acceleration sensor is installed on the upper electrode cantilever and used for collecting the acceleration signal of the upper electrode.

[0029] The upper electrode pressure sensor is installed on the upper electrode cantilever and used for collecting the pressure signal of the upper electrode.

[0030] The upper electrode displacement sensor is installed on the rack and used for collecting the displacement signal of the upper electrode.

[0031] The lower electrode acceleration sensor is installed on the lower electrode cantilever and used for collecting the acceleration signal of the lower electrode.

[0032] The lower electrode pressure sensor is installed on the lower electrode cantilever and used for collecting the pressure signal of the lower electrode.

[0033] The lower electrode displacement sensor is installed on the rack and used for collecting the displacement signal of the lower electrode.

[0034] Each sensor completes signal collection based on a dynamic signal collection module, and sends data to a calculation analysis module for aggregation and transmission;

[0035] The calculation analysis module receives and processes signal data, and outputs calculation results.

[0036] When the multi-sensor measurement system includes different modules, the forms of the operation processing processes f1, f2 and f3 also change, and specific forms will be described in the embodiments, and each form is within the protection scope of the present application.

[0037] Compared with the prior art, the present application has the following beneficial effects:

[0038] 1. The present application uses a multi-sensor to synchronously collect welding dynamic signals of the near end and the far end of the welding area, obtains a smooth electrode displacement signal, avoids the sensor installation interference problem that occurs when measuring the electrode displacement signal in the near end welding area, and can online monitor the micro spot welding process without interfering with the welding process.

[0039] 2. The present application eliminates the displacement signal jitter problem caused by the insufficient rigidity of the large cantilever electrode pressing mechanism, improves the accuracy of the displacement signal measured at the far end; compared with the traditional measurement method without considering vibration filtering, the displacement signal obtained by the present application is reduced by nearly 87% in jitter degree, and is extremely close to the high-precision actual measured displacement signal obtained by high-speed photography, thereby providing technical support for subsequent online monitoring of micro resistance spot welding.

[0040] Other beneficial effects of the present application will be described in the specific embodiments through the introduction of specific technical features and technical solutions, and those skilled in the art should be able to understand the beneficial technical effects brought by the technical features and technical solutions through the introduction of the technical features and technical solutions. BRIEF DESCRIPTION OF DRAWINGS

[0041] Other features, objects and advantages of the present application will become more apparent through reading the following detailed description of the non-limiting embodiments with reference to the accompanying drawings:

[0042] Figure 1 The present application is a method flowchart.

[0043] Figure 2 The present application is a method schematic diagram.

[0044] Figure 3 The present application is a system schematic diagram.

[0045] Figure 4 The present application is an implementation effect diagram.

[0046] LIST OF REFERENCE NUMERALS

[0047] Upper electrode 1 Lower electrode Acceleration sensor 8

[0048] Lower electrode 2 Lower electrode Pressure sensor 9

[0049] Upper electrode Cantilever 3 Lower electrode Displacement sensor 10

[0050] Lower electrode Cantilever 4 Frame 11

[0051] Upper electrode Acceleration sensor 5 Dynamic signal acquisition module 12

[0052] Upper electrode Pressure sensor 6 Computing and analyzing module 13

[0053] Upper electrode Displacement sensor 7 DETAILED DESCRIPTION

[0054] The present application will be described in detail below with specific embodiments. The following examples will help those skilled in the art to further understand the present application, but do not limit the present application in any form. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present application. These are within the scope of the present application.

[0055] Example 1

[0056] Referring to Figure 1 and Figure 2 , the present embodiment provides a micro-resistance spot welding large cantilever electrode displacement signal multi-sensing measurement method and system. Referring to Figure 3 , in this embodiment, the system is composed of upper electrode 1, lower electrode 2, upper electrode cantilever 3, lower electrode cantilever 4, upper electrode displacement sensor 7, lower electrode acceleration sensor 8, lower electrode pressure sensor 9, frame 11, dynamic signal acquisition module 12 and computing and analyzing module 13.

[0057] The upper electrode displacement sensor 7 is installed on the frame 11 for collecting the displacement signal of the upper electrode 1; the lower electrode acceleration sensor 8 is installed on the lower electrode cantilever 4 for collecting the acceleration signal of the lower electrode 2; the lower electrode pressure sensor 9 is installed on the lower electrode cantilever 4 for obtaining the pressure signal of the lower electrode 2.

[0058] Each sensor completes signal acquisition based on the dynamic signal acquisition module 12, and sends the data to the computing and analyzing module 13; the computing and analyzing module 13 receives and processes the signal data, and outputs the calculation result.

[0059] The computing and analyzing module 13 includes a microprocessor, an industrial computer, a PLC, a monitor, a welding controller, a desktop computer, a notebook computer, a server or a workstation.

[0060] The system is used as follows:

[0061] Step one: air pressure and sensor data collection:

[0062] Set different pressures for air pressure. Air pressure refers to controlling the closing of the upper and lower electrodes for a period of time and maintaining a certain electrode pressure, during which no welding current is passed; collect and record the data of the lower electrode acceleration sensor 8 and the lower electrode pressure sensor 9 during the air pressure process; sensor data refers to the output voltage value, which needs to be converted into actual pressure and acceleration according to the sensitivity of the sensor. At the same time, an external sensor is used to measure the displacement of the electrode end.

[0063] Step two: calibration of electrode pressure mechanism stiffness:

[0064] Set 3 different sizes of electrode pressure in the air pressure stage, get the electrode proximal acceleration signal a i (t) under different set pressures through the lower electrode acceleration sensor 8, get the electrode pressure signal F i (t) under different set pressures through the lower electrode pressure sensor 9, and measure the electrode proximal displacement signal S i (t) under different set pressures by using an external sensor, where i = 1, 2, 3.

[0065] Then get the average value of the signal through the following formula, where v i (t) is the speed signal of the electrode proximal end, F i avg , represents the average value of the pressure, displacement, speed and acceleration signals, and T is the collection time of the air pressure stage signal.

[0066] v i (t) = ∫a i (t)dt;

[0067]

[0068] Finally, the electrode pressure mechanism stiffness is calibrated by the following formula, where |·| represents the determinant operation, k, ξ and m are the electrode pressure mechanism stiffness coefficients to be calibrated.

[0069]

[0070] Step three: sample welding and dynamic signal collection:

[0071] Weld the sample, and collect the dynamic signals during the welding process; the dynamic signals include: the displacement signal S m of the upper electrode cantilever root collected by the upper electrode displacement sensor 7, the acceleration signal am and the pressure signal F collected by the lower electrode pressure sensor 9. In this embodiment, Figure 2 F, S, a respectively correspond to the pressure signal F, displacement signal S m and acceleration signal a m .

[0072] Step four: dynamic signal processing to obtain the remote displacement signal and the near-end vibration signal:

[0073] The remote displacement signal refers to the displacement signal away from the welding area; the pressure signal, displacement signal and acceleration signal are coupled to obtain the remote displacement signal S r through the remote displacement signal operation processing process f1(·); the calculation formula of the remote displacement signal operation processing process f1(·) in this embodiment is:

[0074] v m =∫a m dt;

[0075]

[0076] Where v m is the velocity signal of the lower electrode cantilever end, S m is the displacement signal, F is the pressure signal, and k, ξ and m are the stiffness of the electrode pressing mechanism.

[0077] The near-end vibration signal refers to the vibration signal close to the welding area; the acceleration signal is obtained through the near-end vibration signal operation processing process f2(·) to obtain the near-end vibration signal S v ; the calculation formula of the near-end vibration signal operation processing process f2(·) in this embodiment is:

[0078] S v =∫∫a m dt

[0079] Where a m is the acceleration signal.

[0080] Step five: vibration filtering to obtain the electrode displacement signal:

[0081] The remote displacement signal S r and the near-end vibration signal S v are obtained through the vibration filtering operation processing process f3(·) to obtain the electrode displacement signal S e , which deducts the influence of the near-end vibration signal from the remote displacement signal to obtain a smooth displacement signal without jitter, realizing the remote high-precision measurement of the micro electrode displacement signal of the micro resistance spot welding large cantilever. The calculation formula of the vibration filtering operation processing process f3(·) in this embodiment is:

[0082] S e =Sr -S v ;

[0083] The implementation effect of the present application is shown in Figure 4 The multi-sensing high-precision measurement method and system can effectively eliminate the electrode displacement signal jitter problem caused by the insufficient rigidity of the large cantilever mechanism of the micro-resistance spot welding, and compared with the traditional method, the maximum jitter amplitude of the displacement signal is reduced from 6.1 μm to 0.8 μm, which is reduced by nearly 87%; the electrode displacement signal obtained by the method and system is very close to the high-precision electrode displacement signal obtained by high-speed photography, and the maximum error is less than 0.5 μm, which significantly improves the measurement precision of the micro-resistance spot welding electrode displacement signal.

[0084] The present application calibrates the rigidity of the electrode pressurizing mechanism by using the sensing measurement results in the air pressure stage, then performs sample welding and collects the dynamic signals in the welding process, processes the dynamic signals to obtain the far-end displacement signal and the near-end vibration signal, filters the far-end displacement signal according to the near-end vibration signal to obtain the smooth and non-jittering electrode displacement signal, realizes the far-end high-precision measurement of the micro-resistance spot welding large cantilever electrode displacement signal, and can online monitor the micro-spot welding process without interfering with the welding process.

[0085] Embodiment 2

[0086] Referring to Figure 1 and Figure 2 , the present embodiment provides a multi-sensing measurement method and system for the electrode displacement signal of the micro-resistance spot welding large cantilever. Referring to Figure 3 , in this embodiment, the system is composed of an upper electrode 1, a lower electrode 2, an upper electrode cantilever 3, a lower electrode cantilever 4, an upper electrode acceleration sensor 5, an upper electrode pressure sensor 6, a lower electrode acceleration sensor 8, a rack 11, a dynamic signal acquisition module 12 and a calculation and analysis module 13.

[0087] The upper electrode acceleration sensor 5 is installed on the upper electrode cantilever 3 and used for collecting the acceleration signal of the upper electrode 1; the upper electrode pressure sensor 6 is installed on the upper electrode cantilever 3 and used for collecting the pressure signal of the upper electrode 1; the lower electrode acceleration sensor 8 is installed on the lower electrode cantilever 4 and used for collecting the acceleration signal of the lower electrode 2.

[0088] Each sensor completes signal acquisition based on the dynamic signal acquisition module 12, and sends the data to the calculation and analysis module 13; the calculation and analysis module 13 receives and processes the signal data, and outputs the calculation results.

[0089] The calculation and analysis module 13 includes a microprocessor, an industrial computer, a PLC, a monitor, a welding controller, a desktop computer, a notebook computer, a server or a workstation.

[0090] Use the system to perform the following operations:

[0091] Step 1: Collect compressed air and sensor data.

[0092] Different pressures are set for air compression. Air compression refers to controlling the upper and lower electrodes to be closed for a period of time and maintaining a certain electrode pressure, during which no welding current is applied; data from the upper electrode acceleration sensor 5 and the upper electrode pressure sensor 6 are collected and recorded during the air compression process; the sensor data refers to the output voltage value, which needs to be converted into actual acceleration and pressure based on the sensor sensitivity. At the same time, the displacement of the electrode ends is measured using external sensors.

[0093] Step 2: Calibrate the stiffness of the electrode pressurization mechanism:

[0094] Three different electrode pressures are set during the air compression stage, and the proximal electrode acceleration signal a under different set pressures is obtained through the upper electrode acceleration sensor 5. i (t), electrode pressure signals F under different set pressures are obtained through the upper electrode pressure sensor 6. i (t), and the electrode proximal displacement signal S under different set pressures was measured using an external sensor. i (t), where i = 1, 2, 3.

[0095] The signal average value is then obtained using the following formula, where v i (t) is the velocity signal near the electrode, F i avg , This represents the average value of pressure, displacement, velocity, and acceleration signals, where T is the acquisition time of the signal during the air compression stage.

[0096] v i (t)=∫a i (t)dt;

[0097]

[0098] Finally, the stiffness of the electrode pressurization mechanism is obtained by calibration using the following formula, where |·| represents the determinant operation, and k, ξ and m are the stiffness coefficients of the electrode pressurization mechanism to be calibrated.

[0099]

[0100] Step 3: Sample welding and dynamic signal acquisition:

[0101] The sample was welded, and dynamic signals of the welding process were collected simultaneously. These dynamic signals included: acceleration signal a at the end of the upper electrode cantilever, collected by the upper electrode accelerometer 5. m1The pressure signal F collected by the upper electrode pressure sensor 6 and the acceleration signal a collected by the lower electrode acceleration sensor 8 at the end of the lower electrode cantilever. m2 In this embodiment, Figure 2 F, S, and a correspond to the pressure signal F and the acceleration signal a, respectively. m1 and acceleration signal a m2 .

[0102] Step 4: Dynamic signal processing yields distal displacement and proximal vibration signals.

[0103] The remote displacement signal refers to the displacement signal far from the welding area; the pressure signal F is processed by the remote displacement signal calculation process f1(·) to obtain the remote displacement signal S. r In this embodiment, the calculation formula for the far-end displacement signal processing step f1(·) is as follows:

[0104]

[0105] Where k is the stiffness coefficient of the electrode pressurization mechanism.

[0106] Proximal vibration signal refers to the vibration signal near the welding area, acceleration signal a m1 and acceleration signal a m2 The proximal vibration signal S is obtained through the proximal vibration signal processing procedure f2(·). v In this embodiment, the calculation formula for the near-end vibration signal processing step f2(·) is as follows:

[0107] v m1 =∫a m1 dt;v m2 =∫a m2 dt;

[0108]

[0109] Among them, v m1 v is the velocity signal at the end of the upper electrode cantilever. m2 ξ is the velocity signal at the end of the lower electrode cantilever, and k, ξ and m are the stiffness coefficients of the electrode pressurization mechanism.

[0110] Step 5: Obtain the electrode displacement signal through vibration filtering.

[0111] The remote displacement signal S r and proximal vibration signal S v The electrode displacement signal S is obtained through vibration filtering operation process f3(·). eBy subtracting the influence of the near-end vibration signal from the far-end displacement signal, a smooth displacement signal without jitter is obtained, achieving high-precision far-end measurement of the displacement signal of the micro-electrode in the large cantilever of micro-resistance spot welding. In this embodiment, the calculation formula for the vibration filtering operation f3(·) is as follows:

[0112] S e =S r -S v ;

[0113] Example 3

[0114] Reference Figure 1 and Figure 2 As shown, this embodiment provides a multi-sensor measurement method and system for displacement signals of large cantilever electrodes in micro-resistance spot welding. (Refer to...) Figure 3 As shown, in this embodiment, the system consists of an upper electrode 1, a lower electrode 2, an upper electrode cantilever 3, a lower electrode cantilever 4, an upper electrode accelerometer 5, an upper electrode displacement sensor 7, a lower electrode accelerometer 8, a lower electrode displacement sensor 10, a frame 11, a dynamic signal acquisition module 12, and a calculation and analysis module 13.

[0115] The upper electrode accelerometer 5 is mounted on the upper electrode cantilever 3 to collect the acceleration signal of the upper electrode 1; the upper electrode displacement sensor 7 is mounted on the frame 11 to collect the displacement signal of the upper electrode 1; the lower electrode accelerometer 8 is mounted on the lower electrode cantilever 4 to collect the acceleration signal of the lower electrode 2; and the lower electrode displacement sensor 10 is mounted on the frame 11 to collect the displacement signal of the lower electrode 2.

[0116] Each sensor completes signal acquisition based on the dynamic signal acquisition module 12, and sends the data to the calculation and analysis module 13; the calculation and analysis module 13 receives and processes the signal data and outputs the calculation results.

[0117] The calculation and analysis module 13 includes a microprocessor, industrial computer, PLC, monitoring instrument, welding controller, desktop computer, laptop computer, server or workstation.

[0118] Use the system to perform the following operations:

[0119] Step 1: Sample welding and dynamic signal acquisition:

[0120] This embodiment does not require calibration of the electrode pressurization mechanism stiffness. First, the sample is welded, and dynamic signals from the welding process are collected simultaneously. These dynamic signals include: acceleration signal a from the cantilever end of the upper electrode, collected by the upper electrode accelerometer 5. m1 The displacement signal S at the root of the upper electrode cantilever is collected by the upper electrode displacement sensor 7. m1 The acceleration signal a at the end of the lower electrode cantilever is collected by the lower electrode accelerometer 8.m2 and the displacement signal S of the root of the lower electrode cantilever collected by the lower electrode displacement sensor 10 m2 In the present embodiment, Figure 2 F, S, a of the present embodiment correspond to the displacement signal S m1 , S m2 and the acceleration signal a m1 , a m2 .

[0121] Step two: dynamic signal processing to obtain the far-end displacement signal and the near-end vibration signal:

[0122] The far-end displacement signal refers to the displacement signal far from the welding area; the displacement signal S m1 , S m2 The far-end displacement signal S r is obtained through the far-end displacement signal operation processing process f1(·); in the present embodiment, the calculation formula of the far-end displacement signal operation processing process f1(·) is:

[0123] S r = S m1 + f1(S m2 )

[0124] The near-end vibration signal refers to the vibration signal close to the welding area; the acceleration signal a m1 , a m2 The near-end vibration signal S v is obtained through the near-end vibration signal operation processing process f2(·); in the present embodiment, the calculation formula of the near-end vibration signal operation processing process f2(·) is:

[0125] S v = ∫∫a m1 dt + ∫∫a m2 dt

[0126] Step three: vibration filtering to obtain the electrode displacement signal:

[0127] The far-end displacement signal S r and the near-end vibration signal S v are obtained through the vibration filtering operation processing process f3(·) to obtain the electrode displacement signal S e ; in the far-end displacement signal, the influence of the near-end vibration signal is deducted to obtain a smooth displacement signal without jitter, realizing the far-end high-precision measurement of the micro electrode displacement signal of the micro resistance spot welding large cantilever. In the present embodiment, the calculation formula of the vibration filtering operation processing process f3(·) is:

[0128] S e = S r - f3(S v )

[0129] The far-end displacement signal Sr and the near-end vibration signal S v The filtered electrode displacement signal S can be obtained by substituting the above formula e , realize the micro-resistance spot welding large cantilever micro electrode displacement signal remote high precision measurement.

[0130] The present application utilizes multi-sensor synchronous acquisition of welding area near-end and far-end welding dynamic signal, calibrates the electrode pressing mechanism stiffness, then processes the dynamic signal to obtain the far-end displacement signal and the near-end vibration signal, and according to the near-end vibration signal, the far-end displacement signal is vibrated filtered to obtain the smooth electrode displacement signal eliminating the jitter, avoids the sensor installation interference problem appearing in the near-end welding area measurement electrode displacement signal, at the same time eliminates the displacement signal jitter problem caused by the insufficient stiffness of the electrode pressing mechanism, improves the precision of the far-end measurement displacement signal; compared with the traditional measurement method without considering the vibration filtering, the jitter degree of the displacement signal obtained by the present application is reduced by nearly 87%, which is extremely close to the high-precision actual measurement displacement signal obtained by high-speed photography, and provides technical support for subsequent micro-resistance spot welding online monitoring.

[0131] Those skilled in the art know that, in addition to implementing the system provided by the present application and each device, module, unit thereof in a pure computer readable program code manner, the system provided by the present application and each device, module, unit thereof can also be realized in the form of logic gate, switch, application specific integrated circuit, programmable logic controller and embedded microcontroller, etc. by logically programming the method steps to achieve the same function. Therefore, the system provided by the present application and each device, module, unit thereof can be considered as a hardware component, and the devices, modules, units included therein for realizing various functions can also be considered as structures within the hardware component; the devices, modules, units for realizing various functions can also be considered as both software modules realizing the method and structures within the hardware component.

[0132] The specific embodiments of the present application are described above. It needs to be understood that the present application is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essential content of the present application. In the case of no conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A method for multi-sensing measurement of micro-resistance spot welding large cantilever electrode displacement signal, characterized in that, Comprising: Step S1: collecting sensor data in the air pressure process, calibrating the electrode pressure mechanism stiffness; Step S2: welding the sample, collecting the dynamic signal of the welding process; The dynamic signal includes acceleration signal, pressure signal and displacement signal; Step S3: according to the electrode pressure mechanism stiffness, coupling the acceleration signal, pressure signal and displacement signal to obtain the far-end displacement signal and the near-end vibration signal; Wherein, the far-end displacement signal refers to the displacement signal away from the welding area, and the near-end vibration signal refers to the vibration signal close to the welding area; Step S4: using the near-end vibration signal to filter the far-end displacement signal to obtain the filtered electrode displacement signal, and completing the measurement process.

2. The method of claim 1, wherein the micro-resistive spot welding large cantilever electrode displacement signal multi-sensing measurement method is characterized by, The sensor includes part or all of the upper electrode acceleration sensor (5), the upper electrode pressure sensor (6), the upper electrode displacement sensor (7), the lower electrode acceleration sensor (8), the lower electrode pressure sensor (9) and the lower electrode displacement sensor (10); the step S1 includes setting multiple electrode pressure for air pressure, collecting and recording the acceleration signal and pressure signal in the air pressure process, and measuring the displacement of the electrode end at the same time; the electrode pressure mechanism stiffness is calibrated according to the following formula: wherein, and are the pressure signal and acceleration signal of the air pressure stage under different set pressures, respectively; is the measured electrode end displacement signal of the air pressure stage under different set pressures; is the speed signal of the electrode end; i = 1, 2, 3, …, n, represents the air pressure stage under different gear electrode pressures; k , and m are the electrode pressurizing mechanism stiffness coefficients to be calibrated; The pressure signal, displacement signal and acceleration signal in the dynamic signal are processed by a remote displacement signal operation process The remote displacement signal is obtained by coupling S r The acceleration signal is processed by a near-end vibration signal operation process The near-end vibration signal is obtained S v The remote displacement signal and the near-end vibration signal are processed by a vibration filtering operation process The electrode displacement signal is obtained S e When different sensors are used for operation, the operation form of the operation process , , changes.

3. The multi-sensor measurement method for displacement signal of large cantilever electrode in micro-resistance spot welding according to claim 2, characterized in that, If the upper electrode displacement sensor (7), the lower electrode acceleration sensor (8), and the lower electrode pressure sensor (9) are used, the calculation formula of the distal end displacement signal operation processing process is: ： wherein, S r is a remote displacement signal, a m is an acceleration signal collected by the lower electrode acceleration sensor (8), is a velocity signal, S m is a displacement signal collected by the upper electrode displacement sensor (7), F is a pressure signal collected by the lower electrode pressure sensor (9), k , and m is an electrode pressurization mechanism stiffness coefficient; acceleration signal a m through the proximal vibration signal operation process obtaining a proximal vibration signal S v : ： distal displacement signal S r and proximal vibration signal S v by a vibration filtering operation process to obtain a filtered electrode displacement signal S e : ： 。 4. The method of claim 2, wherein the micro-resistance spot welding large cantilever electrode displacement signal is measured by a plurality of sensors. If the upper electrode acceleration sensor (5), the upper electrode pressure sensor (6), and the lower electrode acceleration sensor (8) are used, the calculation formula of the distal end displacement signal operation processing process is: ： wherein, S r is a far-end displacement signal, F is a pressure signal collected by the upper electrode pressure sensor (6), k is an electrode pressurizing mechanism stiffness coefficient; The upper electrode acceleration signal collected by the upper electrode acceleration sensor (5) a m1 The lower electrode acceleration signal collected by the lower electrode acceleration sensor (8) a m2 Through the proximal end vibration signal operation processing process Obtain the proximal end vibration signal S v : ： wherein is the velocity signal of the upper electrode, is the velocity signal of the lower electrode, k , and m is the electrode press mechanism stiffness coefficient; distal displacement signal S r and proximal vibration signal S v by a vibration filtering operation process to obtain a filtered electrode displacement signal S e : ： 。 5. The method of claim 2, wherein the micro-resistance spot welding large cantilever electrode displacement signal is measured by a plurality of sensors. If the upper electrode acceleration sensor (5), the upper electrode displacement sensor (7), the lower electrode acceleration sensor (8), and the lower electrode displacement sensor (10) are used, the calculation formula of the distal end displacement signal operation processing process is as follows. ： wherein, Sr is a remote displacement signal, Sm1 is an upper electrode displacement signal collected by the upper electrode displacement sensor (7), Sm2 is a lower electrode displacement signal collected by the lower electrode displacement sensor (10); The upper electrode acceleration signal collected by the upper electrode acceleration sensor (5) a m1 The lower electrode acceleration signal collected by the lower electrode acceleration sensor (8) a m2 Through the proximal end vibration signal operation processing process Obtain the proximal end vibration signal S v : ： distal displacement signal S r and proximal vibration signal S v by a vibration filtering operation process to obtain a filtered electrode displacement signal S e : ： 。 6. A system for implementing the multi-sensing measurement method of the micro-resistance spot welding large cantilever electrode displacement signal of claim 1, characterized in that, Comprising: Upper electrode (1), lower electrode (2), upper electrode cantilever (3), lower electrode cantilever (4), upper electrode acceleration sensor (5), upper electrode pressure sensor (6), upper electrode displacement sensor (7), lower electrode acceleration sensor (8), lower electrode pressure sensor (9), lower electrode displacement sensor (10), rack (11), dynamic signal acquisition module (12) and calculation analysis module (13); The upper electrode acceleration sensor (5) is installed on the upper electrode cantilever (3) and used for collecting the acceleration signal of the upper electrode (1); The upper electrode pressure sensor (6) is installed on the upper electrode cantilever (3) and used for acquiring the pressure signal of the upper electrode (1); The upper electrode displacement sensor (7) is installed on the rack (11) and used for collecting the displacement signal of the upper electrode (1); The lower electrode acceleration sensor (8) is installed on the lower electrode cantilever (4) and used for collecting the acceleration signal of the lower electrode (2); The lower electrode pressure sensor (9) is installed on the lower electrode cantilever (4) and used for acquiring the pressure signal of the lower electrode (2); The lower electrode displacement sensor (10) is installed on the rack (11) and used for collecting the displacement signal of the lower electrode (2); Each sensor completes signal collection based on the dynamic signal acquisition module (12) and sends the data to the calculation analysis module (13); The calculation analysis module (13) receives and processes the signal data and outputs the calculation result.

7. The system for micro-resistive spot welding multi-sensing measurement of large cantilever electrode displacement signals according to claim 6, characterized in that, Setting multiple electrode pressure for air pressure, collecting and recording the acceleration signal and pressure signal in the air pressure process, and measuring the displacement of the electrode end at the same time; the electrode pressure mechanism stiffness is calibrated according to the following formula: wherein, and are the pressure signal and acceleration signal of the air pressure stage under different set pressures, respectively; are the measured electrode end displacement signals of the air pressure stage under different set pressures; is the speed signal of the electrode end; i = 1, 2, 3, …, n, represents the air pressure stage under different gear electrode pressures; k , and m are the electrode pressurizing mechanism stiffness coefficients to be calibrated; The pressure signal, displacement signal and acceleration signal in the dynamic signal are processed by a remote displacement signal operation process The remote displacement signal is obtained by coupling S r The acceleration signal is processed by a near-end vibration signal operation process The near-end vibration signal is obtained S v The remote displacement signal and the near-end vibration signal are processed by a vibration filtering operation process The electrode displacement signal is obtained S e When different sensors are used for operation, the operation form of the operation process changes , , ​ 8. The system for micro-resistive spot welding multi-sensing measurement of large cantilever electrode displacement signal according to claim 6, characterized in that, If the upper electrode displacement sensor (7), the lower electrode acceleration sensor (8), and the lower electrode pressure sensor (9) are used, the calculation formula of the distal end displacement signal operation processing process is: ： wherein, S r is a remote displacement signal, a m is an acceleration signal collected by the lower electrode acceleration sensor (8), is a velocity signal, S m is a displacement signal collected by the upper electrode displacement sensor (7), F is a pressure signal collected by the lower electrode pressure sensor (9), k , and m is an electrode pressurization mechanism stiffness coefficient; acceleration signal a m through the proximal vibration signal operation process obtaining the proximal vibration signal S v : ： distal displacement signal S r and proximal vibration signal S v by a vibration filtering operation process to obtain a filtered electrode displacement signal S e : ： 。 9. The system for micro-resistive spot welding multi-sensing measurement of large cantilever electrode displacement signal according to claim 6, characterized in that, If the upper electrode acceleration sensor (5), the upper electrode pressure sensor (6), and the lower electrode acceleration sensor (8) are used, the calculation formula of the distal end displacement signal operation processing process is as follows. ： wherein, S r is a far-end displacement signal, F is a pressure signal collected by the upper electrode pressure sensor (6), k is an electrode pressurization mechanism stiffness coefficient; The upper electrode acceleration signal collected by the upper electrode acceleration sensor (5) a m1 The lower electrode acceleration signal collected by the lower electrode acceleration sensor (8) a m2 Through the proximal end vibration signal operation processing process Obtain the proximal end vibration signal S v : ： wherein is the velocity signal of the upper electrode, is the velocity signal of the lower electrode, k , and m is the electrode press mechanism stiffness coefficient; distal displacement signal S r and proximal vibration signal S v by a vibration filtering operation process to obtain a filtered electrode displacement signal S e : ： 。 10. The system for micro-resistive spot welding multi-sensing measurement of large cantilever electrode displacement signals of claim 6, wherein, If the upper electrode acceleration sensor (5), the upper electrode displacement sensor (7), the lower electrode acceleration sensor (8), and the lower electrode displacement sensor (10) are used, the calculation formula of the distal end displacement signal operation processing process is as follows. ： wherein, Sr is a remote displacement signal, Sm1 is an upper electrode displacement signal collected by the upper electrode displacement sensor (7), Sm2 is a lower electrode displacement signal collected by the lower electrode displacement sensor (10); The upper electrode acceleration signal collected by the upper electrode acceleration sensor (5) a m1 The lower electrode acceleration signal collected by the lower electrode acceleration sensor (8) a m2 Through the proximal end vibration signal operation processing process Obtain the proximal end vibration signal S v : ： distal displacement signal S r and proximal vibration signal S v by a vibration filtering operation process to obtain a filtered electrode displacement signal S e : ： 。

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