Argon arc welding pulse signal processing circuit and welding device

Abstract

The application discloses an argon arc welding pulse signal processing circuit and a welding device, which comprises a signal input module, a signal processing module, a signal isolation module and a signal output module connected in sequence; the signal input module is used for collecting the pulse electric signal output by the welding machine, and converting the pulse electric signal into a basic analog voltage signal associated with the characteristics of the pulse electric signal; the signal processing module is used for filtering and amplitude adjusting the basic analog voltage signal to generate a first intermediate analog voltage signal; the signal isolation module is used for electrically isolating the first intermediate analog voltage signal to form the isolated transmission between the strong current and the weak current loop, and generating a second intermediate analog voltage signal; and the signal output module is used for limiting the voltage of the second intermediate analog voltage signal to output a target analog voltage signal meeting the preset parameter range. The application has the effects of improving the welding synchronization precision and the welding anti-interference performance.

Description

Technical Field

[0001] This application relates to the field of welding technology, and in particular to an argon arc welding pulse signal processing circuit and welding apparatus. Background Technology

[0002] In the field of welding technology, especially in TIG welding pulsed current welding scenarios (such as nuclear power equipment welding), accurate pulse signal processing is the core hardware foundation for ensuring welding quality and achieving synchronous control of motors (wire feeder and travel motor). Currently, the core requirements for pulse signal processing circuits in TIG welding focus on two points: First, the circuit must have strong anti-interference capabilities, stably acquiring pulse voltage / current signals under high-frequency arc interference and strong current fluctuations, providing a reliable signal source for arc voltage tracking control and preventing weld defects caused by signal distortion; second, the circuit must achieve signal amplitude adaptation and strong / weak current isolation, ensuring that the processed signal can directly interface with the back-end control unit (such as ADC and MCU), while preventing damage from the high-voltage circuit of the welding machine to the weak-voltage control circuit, providing safe and accurate hardware support for the synchronization of the wire feeder / travel motor and the welding pulse frequency.

[0003] The existing circuits lack a fully optimized architecture, have limited signal amplitude adjustment methods, making it difficult to adapt to the input requirements of different back-end units. Furthermore, the output lacks effective protection design, making it susceptible to damage to precision components due to overvoltage. At the same time, some solutions with isolation designs also lack matching mechanisms, resulting in significant signal attenuation and poor linearity after isolation. This fails to meet the precise pulse dynamic characteristics capture requirements of motor synchronous control, leading to problems such as wire feeding timing misalignment, material waste, and weld defects.

[0004] In response to the aforementioned technologies, existing pulse signal processing circuits suffer from weak anti-interference capabilities, low signal processing accuracy, and imperfect isolation between strong and weak currents, making them unsuitable for meeting the stringent hardware requirements of argon arc welding pulse welding. Therefore, there is an urgent need for a fully optimized and highly reliable argon arc welding pulse signal processing circuit solution.

[0005] In response to the aforementioned technologies, existing pulse signal processing circuits suffer from weak anti-interference capabilities, low signal processing accuracy, and imperfect strong-weak electrical isolation, making them unsuitable for meeting the stringent hardware requirements of argon arc welding pulse welding. Therefore, a highly reliable argon arc welding pulse signal processing circuit solution is urgently needed. Summary of the Invention

[0006] To address the aforementioned technical problems, this application provides an argon arc welding pulse signal processing circuit and a welding apparatus.

[0007] Firstly, the argon arc welding pulse signal processing circuit provided in this application adopts the following technical solution:

[0008] An argon arc welding pulse signal processing circuit includes:

[0009] The system comprises a signal input module, a signal processing module, a signal isolation module, and a signal output module connected in series. The signal input module acquires the pulse electrical signal output by the welding machine and converts it into a basic analog voltage signal associated with the characteristics of the pulse electrical signal. The signal processing module filters and adjusts the amplitude of the basic analog voltage signal to generate a first intermediate analog voltage signal. The signal isolation module performs electrical isolation processing on the first intermediate analog voltage signal to form an isolated transmission between high-voltage and low-voltage circuits, generating a second intermediate analog voltage signal. The signal output module limits the voltage of the second intermediate analog voltage signal and outputs a target analog voltage signal that meets the preset parameter range.

[0010] By adopting the above technical solution, this circuit addresses the problems in existing TIG welding pulse welding, where traditional signal processing circuits are not adapted to the characteristics of the welding machine's high-voltage pulses, are susceptible to high-frequency interference and interference from shared grounding of strong and weak currents, and suffer from signal amplitude mismatch with the input of subsequent control units, resulting in low sampling accuracy and easy circuit damage. This circuit constructs a solution based on "modular series connection + full-process signal optimization": On one hand, the signal input module, through Hall effect sensing, impedance conversion, transient suppression, voltage regulation, and voltage divider design, converts the welding machine's high-voltage pulses into a basic voltage signal that retains the period and amplitude characteristics, preventing damage to subsequent circuits from high-voltage surges; on the other hand, the low-pass filter of the signal processing module filters out high-frequency noise from the welding environment, and amplitude adjustment adapts the signal to the input range of the isolation module; the signal isolation module physically separates the strong and weak current circuits, solving the problem of shared grounding interference; and the amplitude limiting design of the signal output module clamps the signal within a safe range, ensuring a stable and reliable output signal. This circuit, through module collaboration, achieves precise processing of the pulse signal from acquisition to output (arc voltage tracking), providing a high-quality analog sampling signal for welding synchronization control, and meeting the stringent requirements of TIG welding pulse welding for signal accuracy and circuit safety.

[0011] Optionally, the signal input module includes: a transient suppression diode ZD, an input resistor R0, a Zener diode D0, and a first voltage divider resistor network; one end of the transient suppression diode ZD is connected to the welding machine pulse signal, and the other end is connected to the input resistor R0. The Zener diode D0 is connected in parallel between the output terminal of the input resistor R0 and ground. The positive terminal of the Zener diode D0 is grounded, and the negative terminal is connected to the output terminal of the input resistor R0. The output terminal of the input resistor R0 is connected to the input terminal of the first voltage divider resistor network. The first voltage divider resistor network is connected between ground and the input resistor R0 and includes a first resistor R1 and a second resistor R2 connected in series. The connection point of the first resistor R1 and the second resistor R2 is the output terminal, used to output the basic analog voltage signal.

[0012] By adopting the above technical solutions, the signal input module achieves "high-voltage protection + signal conversion": the transient suppression diode ZD can absorb instantaneous low-voltage surges during signal transmission, preventing interference signals from entering the subsequent stage; the input resistor R0 can reduce the static power consumption of the circuit and prevent excessive current from impacting the subsequent components; the Zener diode can stabilize and clamp the voltage at the output terminal of the input resistor R0 to a fixed value, eliminating the small fluctuations in the output voltage of the previous stage caused by load changes or environmental interference; the first voltage divider resistor network linearly attenuates the low-amplitude voltage signal into a low-amplitude basic analog voltage signal, which not only retains the periodic and amplitude variation characteristics of the pulse electrical signal, but also provides a standard input for the subsequent signal processing module, solving the problems of lack of protection and signal conversion distortion in traditional input circuits.

[0013] Optionally, the first voltage divider resistor network also includes an eleventh resistor R11 and a twelfth resistor R12, with the eleventh resistor R11 connected in parallel with the first resistor R1 and the twelfth resistor R12 connected in parallel with the second resistor R2.

[0014] By adopting the above technical solution, the parallel resistors (R11 and R1, R12 and R2) achieve fine adjustment of the voltage division ratio and redundancy backup: on the one hand, the voltage division ratio can be precisely controlled by adjusting the resistance value of the parallel resistors to ensure that the amplitude of the basic analog voltage signal meets the design requirements; on the other hand, when one of the resistors fails, the parallel resistors can temporarily maintain the voltage division function, improve the fault tolerance and reliability of the circuit, and adapt to the stability requirements of long-term continuous operation during argon arc welding.

[0015] Optionally, the signal processing module includes a first voltage follower VF1, a low-pass filter circuit, and a second voltage divider resistor network connected in series. The input of the first voltage follower VF1 is connected to a basic analog voltage signal, and the output is connected to the low-pass filter circuit. The low-pass filter circuit includes an RC circuit and a first amplifier OP1. The RC circuit is connected to the non-inverting input of the first voltage follower VF1 and the first amplifier OP1. A third resistor R3 is connected between the inverting input and the output of the first amplifier OP1. The third resistor R3 is used to set the amplification factor. The second voltage divider resistor network includes a fourth resistor R4, a fifth resistor R5, and a sixth resistor R6 connected in series between the output of the first amplifier OP1 and ground. The fourth resistor R4 is connected to the output of the first amplifier OP1, the sixth resistor R6 is grounded, and the connection point of the fifth resistor R5 and the sixth resistor R6 is the output terminal, used to output a first intermediate analog voltage signal.

[0016] By adopting the above technical solution, the signal processing module achieves "signal buffering + noise suppression + precise amplitude adjustment": the high input impedance of the first voltage follower VF1 can prevent the load of the input signal from the subsequent circuit and ensure the stability of the basic analog voltage signal; the low-pass filter circuit filters out high-frequency interference in the welding environment and retains the pulse fundamental frequency characteristics; the first amplifier OP1 sets the amplification factor through the third resistor R3 to realize the signal amplitude enhancement; the second voltage divider resistor network (R4, R5, R6) further adjusts the amplitude so that the first intermediate analog voltage signal is accurately matched to the input range of the signal isolation module, solving the problems of signal attenuation and incomplete noise filtering in traditional processing circuits.

[0017] Optionally, the low-pass filter circuit has a cutoff frequency of 723Hz and an amplification factor of 4.

[0018] By adopting the above technical solution, specific parameters are designed to adapt to the characteristics of the argon arc welding pulse signal. The low-pass filter circuit with a cutoff frequency of 723Hz can accurately filter out high-frequency signals (usually higher than 1kHz) such as arc interference and motor noise during the welding process, while fully preserving the low-frequency pulse signals commonly used in pulse welding (such as 50-700Hz). The 4x amplification factor can boost the filtered low-amplitude signal to the input range of the linear optocoupler, preventing isolation transmission distortion caused by weak signals, ensuring signal processing accuracy, and further adapting to the signal characteristic requirements of argon arc welding pulse welding.

[0019] Optionally, the signal isolation module includes a linear optocoupler OC and a second amplifier OP2 connected in series. The primary side of the linear optocoupler OC receives the first intermediate analog voltage signal, and the secondary side is connected to the non-inverting input and the inverting input of the second amplifier OP2 to amplify the first intermediate analog voltage signal. A seventh resistor R7 is provided between the inverting input and the output of the second amplifier OP2, and the output of the second amplifier OP2 is used to output the second intermediate analog voltage signal.

[0020] By adopting the above technical solution, the signal isolation module achieves "strong and weak current isolation + signal amplification": the linear optocoupler OC replaces the direct transmission of electrical signals with optical signal transmission, cutting off the electrical connection between the strong current circuit (welding machine side) and the weak current circuit (back-end ADC side), preventing grounding interference and the risk of strong current interference; the second amplifier OP2 sets the amplification factor to further amplify the signal after transmission by the linear optocoupler, compensate for the signal attenuation during the isolation process, and ensure that the amplitude of the second intermediate analog voltage signal meets the subsequent limiting and sampling requirements, solving the problems of high signal loss and weak anti-interference capability of traditional isolation circuits.

[0021] Optionally, the secondary side of the linear optocoupler OC includes a first output pin and a second output pin. The first output pin is connected to the non-inverting input of the second amplifier OP2 via an eighth resistor R8, and the second output pin is connected to the inverting input of the second amplifier OP2 via a ninth resistor R9. The eighth resistor R8 and the ninth resistor R9 are used for current limiting and impedance matching.

[0022] By adopting the above technical solution, the current-limiting resistors (R8, R9) achieve "current protection + impedance matching": on the one hand, they limit the output current of the secondary side of the linear optocoupler to prevent excessive current from damaging the input terminal of the second amplifier OP2; on the other hand, by matching the resistor values, they make the output impedance of the secondary side of the linear optocoupler consistent with the input impedance of the second amplifier, reducing signal reflection and distortion, ensuring the integrity of the isolated signal, and further improving the isolation transmission accuracy.

[0023] Optionally, the second intermediate analog voltage signal is amplified by 16 times relative to the first intermediate analog voltage signal.

[0024] By adopting the above technical solution, the 16x total amplification factor design achieves a step-by-step increase in signal amplitude: combined with the 4x amplification of the signal processing module, the total amplification factor from the basic analog voltage signal to the second intermediate analog voltage signal is controllable. This prevents noise superposition caused by an insufficiently weak initial signal and distortion caused by an excessively strong signal. Ultimately, the amplitude of the second intermediate analog voltage signal is placed within a reasonable range of the signal output module's amplitude limiting range, providing a high-quality signal for subsequent amplitude limiting processing and ADC sampling, and adapting to the amplitude characteristics of the argon arc welding pulse signal.

[0025] Optionally, the signal output module includes a second voltage follower VF2 and a limiting circuit; the limiting circuit includes a first diode D1 and a second diode D2 connected in reverse series, the anode of the first diode D1 is connected to the reference voltage, the cathode of the second diode D2 is grounded, and the connection point of the first diode D1 and the second diode D2 forms a common node. The input terminal of the second voltage follower VF2 is connected to a second intermediate analog voltage signal, and the output terminal is connected to the common node. The common node serves as the output terminal of the limiting circuit for outputting the target analog voltage signal.

[0026] By adopting the above technical solution, the signal output module achieves "signal buffering + voltage clamping": the second voltage follower VF2 ensures the output terminal has the load-carrying capacity, avoiding the influence of the subsequent ADC unit on the signal; the limiting circuit clamps the upper limit of the standard analog sampling signal to the reference voltage and the lower limit to the ground voltage through reverse series diodes (D1, D2), preventing overvoltage damage to the ADC unit, while ensuring that the output signal amplitude is stable within the preset range, solving the problems of no protection and signal amplitude exceeding the limit in traditional output circuits, and providing a safe and reliable analog signal for digital sampling.

[0027] Secondly, the welding apparatus provided in this application adopts the following technical solution:

[0028] A welding apparatus comprising an argon arc welding pulse signal processing circuit as described in any one of the first aspects above.

[0029] By adopting the above technical solution, the welding device integrates a dedicated argon arc welding pulse signal processing circuit. Compared with traditional devices without precise signal processing circuits, it can achieve safe and accurate processing of high-voltage pulse signals in argon arc welding pulse welding. On the one hand, the circuit reduces the impact of high-voltage and high-frequency interference from the welding machine on the control loop through transient suppression and electrical isolation designs, improving the safety and stability of the device. On the other hand, after filtering, amplitude adjustment, and limiting, the analog sampling signal adapted to the sampling requirements can be directly adapted to the ADC unit and control module in the device, providing a high-quality signal reference for the synchronous control of the wire feeding motor and the walking motor. This ensures that the motor action and the welding pulse cycle are accurately matched, reducing material waste caused by ineffective wire feeding and lowering the weld defect rate. It is especially suitable for argon arc welding pulse welding scenarios with stringent requirements for welding accuracy and reliability, such as the nuclear power field, while also improving the overall anti-interference capability and signal processing efficiency of the device.

[0030] In summary, this application includes at least one of the following beneficial technical effects:

[0031] 1. By adopting the above technical solution, this circuit addresses the problems in existing TIG welding pulse welding, where traditional signal processing circuits are not adapted to the characteristics of the welding machine's high-voltage pulses, are susceptible to high-frequency interference and interference from common ground of strong and weak currents, and suffer from signal amplitude mismatch with the input of subsequent control units, resulting in low sampling accuracy and easy circuit damage. This circuit constructs a solution using "modular series connection + full-process signal optimization": On one hand, the signal input module, through Hall effect sensing, impedance conversion, transient suppression, voltage regulation, and voltage divider design, converts the welding machine's high-voltage pulses into a basic voltage signal that retains the period and amplitude characteristics, preventing damage to subsequent circuits from high-voltage surges; on the other hand, the low-pass filter of the signal processing module can filter out high-frequency noise in the welding environment, and amplitude adjustment adapts the signal to the input range of the isolation module; the signal isolation module achieves physical separation of strong and weak current circuits, solving the problem of common ground interference; and the amplitude limiting design of the signal output module clamps the signal within a safe range, ensuring a stable and reliable output signal. This circuit achieves precise processing of pulse signals from acquisition to output (arc voltage tracking) through module collaboration, providing high-quality analog sampling signals for welding synchronization control, and adapting to the stringent requirements of argon arc welding pulse welding for signal accuracy and circuit safety.

[0032] 2. By adopting the above technical solution, a low-pass filter circuit with a cutoff frequency of 723Hz is designed to adapt to the characteristics of the TIG welding pulse signal. This circuit can accurately filter out high-frequency signals (usually higher than 1kHz) such as arc interference and motor noise during the welding process, while fully preserving the low-frequency pulse signals commonly used in pulse welding (such as 50-700Hz). The 4x amplification factor can boost the filtered low-amplitude signal to the input range of the linear optocoupler, preventing isolation transmission distortion caused by weak signals, ensuring signal processing accuracy, and further adapting to the signal characteristic requirements of TIG welding pulse welding.

[0033] 3. By adopting the above technical solution, the welding device integrates a dedicated argon arc welding pulse signal processing circuit. Compared with traditional devices without precise signal processing circuits, it can achieve safe and precise processing of high-voltage pulse signals in argon arc welding pulse welding. On the one hand, the circuit, through transient suppression and electrical isolation designs, prevents the high voltage and high-frequency interference of the welding machine from affecting the control loop, thereby improving the safety and stability of the device. On the other hand, after filtering, amplitude adjustment, and limiting, the target analog sampling signal adapted to the sampling requirements can be directly adapted to the ADC unit and control module in the device, providing a high-quality signal reference for the synchronous control of the wire feeding motor and the walking motor. This ensures that the motor action and the welding pulse cycle are precisely matched, reducing material waste caused by ineffective wire feeding and lowering the weld defect rate. It is especially suitable for argon arc welding pulse welding scenarios with stringent requirements for welding accuracy and reliability, such as the nuclear power field, while also improving the overall anti-interference capability and signal processing efficiency of the device. Attached Figure Description

[0034] Figure 1 This is a circuit block diagram of the argon arc welding pulse signal processing circuit provided in the embodiments of this application;

[0035] Figure 2 This is a circuit structure diagram of the argon arc welding pulse signal processing circuit provided in the embodiments of this application;

[0036] Figure 3 This is a flowchart of the welding pulse signal processing method provided in the embodiments of this application.

[0037] Explanation of reference numerals in the attached figures:

[0038] 1. Input module; 2. Signal processing module; 3. Signal isolation module; 4. Signal output module. Detailed Implementation

[0039] The following is in conjunction with the appendix Figure 1-3 This application will be described in further detail.

[0040] Reference Figure 1 and Figure 2This application discloses an argon arc welding pulse signal processing circuit, comprising: a signal input module 1, a signal processing module 2, a signal isolation module 3, and a signal output module 4 connected in series; the signal input module 1 is used to acquire the pulse electrical signal output by the welding machine and convert the pulse electrical signal into a basic analog voltage signal associated with the characteristics of the pulse electrical signal; the signal processing module 2 is used to filter and adjust the amplitude of the basic analog voltage signal to generate a first intermediate analog voltage signal; the signal isolation module 3 is used to perform electrical isolation processing on the first intermediate analog voltage signal to form an isolated transmission of high-voltage and low-voltage circuits and generate a second intermediate analog voltage signal; the signal output module 4 is used to limit the voltage amplitude of the second intermediate analog voltage signal and output a target analog voltage signal that meets the preset parameter range.

[0041] By adopting the above technical solution, this circuit addresses the problems in existing TIG welding pulse welding, where traditional signal processing circuits are not adapted to the characteristics of the welding machine's high-voltage pulses, are susceptible to high-frequency interference and interference from common ground of strong and weak currents, and suffer from low sampling accuracy and circuit damage due to mismatch between signal amplitude and subsequent control unit input. The solution is built using a "modular series + full-process signal optimization" approach: On one hand, signal input module 1, through Hall effect sensing, impedance conversion, transient suppression, voltage regulation, and voltage divider design, converts the welding machine's high-voltage pulses into a basic voltage signal that retains the period and amplitude characteristics, preventing damage to subsequent circuits from high-voltage surges; on the other hand, the low-pass filter of signal processing module 2 filters out high-frequency noise from the welding environment, and amplitude adjustment adapts the signal to the input range of the isolation module; signal isolation module 3 achieves physical separation of strong and weak current circuits, solving the common ground interference problem; and the amplitude limiting design of signal output module 4 clamps the signal within a safe range, ensuring a stable and reliable output signal. This circuit achieves precise processing of pulse signals from acquisition to output (arc voltage tracking) through module collaboration, providing high-quality analog sampling signals for welding synchronization control, and adapting to the stringent requirements of argon arc welding pulse welding for signal accuracy and circuit safety.

[0042] Reference Figure 2 In one embodiment, the signal input module 1 includes: a transient suppression diode ZD, an input resistor R0, a Zener diode D0, and a first voltage divider resistor network; one end of the transient suppression diode ZD is connected to the welding machine pulse signal, and the other end is connected to the input resistor R0. The Zener diode D0 is connected in parallel between the output terminal of the input resistor R0 and ground. The positive terminal of the Zener diode D0 is grounded, and the negative terminal is connected to the output terminal of the input resistor R0. The output terminal of the input resistor R0 is connected to the input terminal of the first voltage divider resistor network. The first voltage divider resistor network is connected between ground and the input resistor R0 and includes a first resistor R1 and a second resistor R2 connected in series. The connection point of the first resistor R1 and the second resistor R2 is the output terminal, used to output a basic analog voltage signal.

[0043] Specifically, the input preamplifier of signal input module 1 also includes a Hall sensor and an impedance conversion circuit (not shown in the figure). First, the Hall sensor (such as ACS712) senses the output current signal of the welding machine, and the impedance conversion circuit (such as a 200Ω low-temperature drift resistor) generates an initial analog voltage signal of 0-5V. The input terminal of the transient suppression diode ZD is connected to the 0-5V voltage signal. The transient suppression diode ZD is selected to be a model suitable for low-voltage scenarios (such as SMBJ6.5CA), with a rated reverse turn-off voltage of 6.5V and a maximum clamping voltage of 10V, which can absorb Hall signals. To prevent transient low-voltage surges (such as voltage spikes caused by line interference) that may occur during sensor signal transmission, interference signals are prevented from entering subsequent stages. The input resistor R0 is a 100kΩ±0.1% high-precision power resistor with a rated power ≥0.5W. Based on the initial analog voltage signal of 0-5V, according to Ohm's law, the input current can be limited to within 50μA (I=U / R=5V / 100kΩ), which reduces the circuit's static power consumption and prevents excessive current from impacting subsequent components. The Zener diode D0 is a 12V-1W high-precision... A Zener diode (such as BZX84C12) with a reverse breakdown voltage accuracy of ±5% can clamp the voltage at the output of the input resistor R0 to 12V, eliminating minor fluctuations in the Hall sensor output voltage caused by load changes or environmental interference (such as a 0.2V deviation in a 0-5V signal), ensuring the voltage stability of the input voltage divider network. The first resistor R1 and the second resistor R2 in the first voltage divider network are both 4.7kΩ ±0.1% high-precision resistors. According to the voltage divider formula Uout=U... The 5V clamping voltage, after passing through the voltage divider network (in×R2 / R1+R2), outputs a basic analog voltage of approximately 0-2.5V. Because the resistors are all ±0.1% accurate, it ensures a linear correspondence between the initial analog voltage signal (0-5V) and the divided basic analog voltage (0-2.5V), fully preserving the amplitude variation characteristics of the original signal. Simultaneously, this basic analog voltage is compatible with the low-range input characteristics of the subsequent operational amplifier, providing a standard and stable input signal for subsequent filtering and amplification stages, thus solving the problems of lack of protection and signal conversion distortion in traditional input circuits.

[0044] In one embodiment, the first voltage divider resistor network further includes an eleventh resistor R11 and a twelfth resistor R12. The eleventh resistor R11 is connected in parallel with the first resistor R1, and the twelfth resistor R12 is connected in parallel with the second resistor R2. Preferably, both resistors have NC resistance (i.e., unmounted state). Whether to mount resistors with appropriate resistance values ​​can be determined according to the actual voltage division accuracy requirements. If a slight deviation is found in the output voltage of the basic voltage divider network composed of the first resistor R1 and the second resistor R2 during subsequent debugging, R11 and R12 with corresponding resistance values ​​can be mounted. The voltage division ratio can be corrected to the design standard value through the resistance compensation of the parallel resistors. For example, when the basic voltage division output is 0.05V higher than the preset value, a high-resistance R11 can be mounted in parallel with R1 to slightly reduce the equivalent resistance of the first resistor R1, thereby fine-tuning the voltage division output to the target voltage.

[0045] By adopting the above technical solution, the parallel resistors (R11 and R1, R12 and R2) achieve fine adjustment of the voltage division ratio and redundancy backup: on the one hand, the voltage division ratio can be precisely controlled by adjusting the resistance value of the parallel resistors to ensure that the amplitude of the basic analog voltage signal meets the design requirements; on the other hand, when one of the resistors fails, the parallel resistors can temporarily maintain the voltage division function, improve the fault tolerance and reliability of the circuit, and adapt to the stability requirements of long-term continuous operation during argon arc welding.

[0046] Reference Figure 2 In one embodiment, the signal processing module 2 includes a first voltage follower VF1, a low-pass filter circuit, and a second voltage divider resistor network connected in series. The input terminal of the first voltage follower VF1 is connected to a basic analog voltage signal, and the output terminal is connected to the low-pass filter circuit. The low-pass filter circuit includes an RC circuit and a first amplifier OP1. The RC circuit is connected to the non-inverting input terminals of the first voltage follower VF1 and the first amplifier OP1. A third resistor R3 is connected between the inverting input terminal and the output terminal of the first amplifier OP1. The third resistor R3 is used to set the amplification factor. The second voltage divider resistor network includes a fourth resistor R4, a fifth resistor R5, and a sixth resistor R6 connected in series between the output terminal of the first amplifier and ground. The fourth resistor R4 is connected to the output terminal of the first amplifier, the sixth resistor R6 is grounded, and the connection point of the fifth resistor R5 and the sixth resistor R6 is the output terminal, used to output a first intermediate analog voltage signal.

[0047] Specifically, the first voltage follower VF1 uses a low-noise dual op-amp with an input impedance ≥10¹²Ω and an output impedance ≤100Ω (such as TL072CDT), adapting to the high impedance input requirements of the basic analog voltage signal (approximately 2.5V) and reducing signal transmission loss. The RC circuit consists of a first capacitor C1 and a tenth resistor R10. Preferably, C1 is a 220nF ceramic capacitor and R10 is a 1kΩ ±0.1% metal film resistor, used to filter out high-frequency interference in the basic analog voltage signal. The cutoff frequency formula of the low-pass filter circuit is fc=1 / 2πRC, where the resistor R is R10=1kΩ and the capacitor C is C1=220nF. Substituting into the formula, we get 723Hz, which can effectively filter out high-frequency interference above 723Hz and retain the low-frequency useful components of the basic analog voltage signal. The first amplifier OP1 includes a dual op-amp of the same model as VF1 (TL072CDT), the difference being that a third resistor R3 is provided between the inverting input terminal and the output terminal. Simultaneously, the inverting input terminal is grounded through resistor R31. R3 and R31 work together to set the amplification factor. Preferably, R3 = 40kΩ ± 0.1%, R31 = 10kΩ ± 0.1%, and the amplification factor K = R3 / R31 = 4. The basic analog voltage signal (0-2.5V) is amplified to output 0.0~10.0V. C1, R10, and OP1 together constitute a low-pass filter circuit with a cutoff frequency of 723Hz and an amplification factor of 4. The second voltage divider resistor network includes the... The four resistors R4, the fifth resistor R5, and the sixth resistor R6 are preferably R4=10kΩ±0.1%, R5=39kΩ±0.1%, and R6=1kΩ±0.1%, all of which are high-precision metal film resistors. The total resistance after series connection is 50kΩ. They are used to divide the output signal of OP1. The 0.0~10.0V amplified signal is calculated by the voltage division ratio (R6 / R4+R5+R6=0.02) to output a first intermediate analog voltage signal with an amplitude of 0.0~200mV.

[0048] By adopting the above technical solution, signal processing module 2 achieves "signal buffering + noise suppression + precise amplitude adjustment": the high input impedance characteristic of the first voltage follower VF1 prevents the load influence of subsequent circuits on the input signal, ensuring the stability of the basic analog voltage signal; the low-pass filter circuit (e.g., 723Hz cutoff frequency) filters out high-frequency interference in the welding environment, preserving the pulse fundamental frequency characteristics; the first amplifier OP1 sets the amplification factor (e.g., 4 times) through the third resistor R3 to achieve signal amplitude enhancement; the second voltage divider resistor network (R4, R5, R6) further adjusts the amplitude, making the first intermediate analog voltage signal accurately adapted to the signal isolation module 3. The input range addresses the issues of uncontrolled signal attenuation and incomplete noise filtering in traditional processing circuits. Furthermore, by designing specific parameters to adapt to the characteristics of TIG welding pulse signals, such as a low-pass filter circuit with a 723Hz cutoff frequency, it can accurately filter out high-frequency signals (typically higher than 1kHz) such as arc interference and motor noise during welding, while fully preserving the low-frequency pulse signals commonly used in pulse welding (such as 50-700Hz). A 4x amplification factor can boost the filtered low-amplitude signal to a range suitable for linear optocouplers, preventing signal weakness that could cause transmission distortion and ensuring signal processing accuracy, further adapting to the signal characteristics requirements of TIG welding pulse welding.

[0049] Reference Figure 2 In one embodiment, the signal isolation module 3 includes a linear optocoupler OC and a second amplifier OP2 connected in series. The primary side of the linear optocoupler OC receives a first intermediate analog voltage signal, and the secondary side is connected to the non-inverting input and the inverting input of the second amplifier OP2 for amplifying the first intermediate analog voltage signal. A seventh resistor R7 is provided between the inverting input and the output of the second amplifier OP2. The output of the second amplifier OP2 is used to output a second intermediate analog voltage signal. The secondary side of the linear optocoupler OC includes a first output pin and a second output pin. The first output pin is connected to the non-inverting input of the second amplifier OP2 via an eighth resistor R8, and the second output pin is connected to the inverting input of the second amplifier OP2 via a ninth resistor R9. The eighth resistor R8 and the ninth resistor R9 are used for current limiting and impedance matching.

[0050] Specifically, the linear optocoupler OC should be a model with linear amplification characteristics (such as the HCPL-7840 series). Its primary side should be compatible with a first intermediate analog voltage signal input of 0.0~200mV, with a built-in fixed amplification factor (k=8). This enables electrical isolation between the input and output terminals, cutting off the electrical connection between the high-voltage circuit (welding machine side) and the low-voltage circuit (back-end ADC side), blocking high-frequency interference transmission, and simultaneously performing preliminary signal amplification. Its primary-side input impedance and the subsequent output impedance must match the signal amplitude to reduce signal transmission loss. Preferably, the linear optocoupler OC is compatible with 0.0~200mV analog voltage signals. The first intermediate analog voltage signal of mV is isolated and initially amplified. The output voltage formula is Uout = Uin × k, where: Uin is the first intermediate analog voltage signal (range 0.0~200mV); k is the built-in amplification factor of the linear optocoupler (k=8). Substituting the values: when Uin=200mV, Uout=1.6V, that is, the output signal range of the linear optocoupler OC is 0.0~1.6V, which retains the original signal amplitude characteristics and reduces interference through isolation. The secondary side of the linear optocoupler OC includes the first output pin (labeled 7) and the second output pin. Pin 6 (labeled 6) is connected to the non-inverting input of the second amplifier OP2 via resistor R8 (eighth resistor), and to the inverting input of the second amplifier OP2 via resistor R9 (ninth resistor). Resistors R8 and R9 are used for current limiting and impedance matching. Preferably, R8 = R9 = 10kΩ ± 0.1%, used for "current protection + impedance matching": on the one hand, limiting the output current of the linear optocoupler secondary side to prevent excessive current from damaging the input of the second amplifier OP2; on the other hand, by matching the resistor values, making the output impedance of the linear optocoupler secondary side match that of the second amplifier OP2. The two amplifiers have the same input impedance, which reduces signal reflection and distortion, ensures the integrity of the isolated signal, and further improves the isolation transmission accuracy. Preferably, the second amplifier OP2 is a low-noise operational amplifier (the same model as the previous stage OP1, such as TL072CDT), with an open-loop gain ≥100dB, to ensure the accuracy of the secondary amplification of the signal. The feedback branch of this amplifier is composed of the seventh resistor R7 and the ninth resistor R9 connected in series. R7 and R9 are connected between the output terminal and the inverting input terminal of the previous stage linear optocoupler OC. Preferably, R7 is a high-precision metal film resistor of 20kΩ±0.1%.With amplification factor K=R7 / R9=2, when the output signal range of the linear optocoupler OC is 0.0~1.6V, the second intermediate analog voltage signal, after being amplified by the second amplifier OP2, has an output voltage range of 0.0~3.2V. Compared with the first intermediate analog voltage signal (range 0.0~200mV), the voltage signal is amplified by 16 times, realizing a step-by-step increase in signal amplitude. Combined with the 4x amplification of the signal processing module 2, the total amplification factor from the basic analog voltage signal to the second intermediate analog voltage signal is controllable. This prevents noise superposition caused by an initially weak signal and distortion caused by an excessively strong signal. Ultimately, the amplitude of the second intermediate analog voltage signal is within a reasonable range of the amplitude limiting range of the signal output module 4, providing a high-quality signal for subsequent amplitude limiting processing and ADC sampling, and adapting to the amplitude characteristics of the argon arc welding pulse signal.

[0051] By adopting the above technical solution, the signal isolation module 3 achieves "strong and weak current isolation + signal amplification": the linear optocoupler OC replaces the direct transmission of electrical signals with optical signal transmission, cuts off the electrical connection between the strong current circuit (welding machine side) and the weak current circuit (back-end ADC side), and prevents grounding interference and the risk of strong current intrusion; the second amplifier OP2 sets the amplification factor to further amplify the signal after the linear optocoupler transmission, compensates for the signal attenuation during the isolation process, and ensures that the amplitude of the second intermediate analog voltage signal meets the subsequent limiting and sampling requirements, thus solving the problems of large signal loss and weak anti-interference ability of traditional isolation circuits.

[0052] Reference Figure 2 In one embodiment, the signal output module 4 includes a second voltage follower VF2 and a limiting circuit. The limiting circuit includes a first diode D1 and a second diode D2 connected in reverse series. The positive terminal of the first diode D1 is connected to a reference voltage, and the negative terminal of the second diode D2 is grounded. The connection point of the first diode D1 and the second diode D2 forms a common node. The input terminal of the second voltage follower VF2 is connected to a second intermediate analog voltage signal, and the output terminal is connected to the common node. The common node serves as the output terminal of the limiting circuit for outputting a target analog voltage signal that meets the preset parameter range.

[0053] Specifically, the second voltage follower VF2 uses the same low-noise operational amplifier (such as TL072CDT) as the first voltage follower VF1, with an input impedance ≥10¹²Ω and an output impedance ≤100Ω. The second intermediate analog voltage signal (0.0~3.2V) received at its input terminal is buffered by VF2, which significantly improves the load-carrying capacity of the output terminal, making it compatible with the input impedance requirements of the subsequent ADC unit (analog-to-digital conversion module) and preventing the input current of the ADC unit from affecting the signal amplitude. In the limiting circuit (D1, D2), D1 and D2 are preferably ordinary silicon diodes (such as 1N4148), with a forward conduction voltage drop of about 0.7V. The reference voltage connected to the positive terminal of D1 is set to 3.3V (compatible with the full-scale input voltage of most ADC units). D2 is connected in series with D1 in reverse, and the negative terminal is grounded (0V). The common node formed by the connection of the two receives the output signal of VF2 and achieves voltage clamping through the conduction characteristics of the diode. When the input signal exceeds 3.3V + 0.7V = 4V, D1 conducts forward, clamping the upper limit of the signal at 4V; when the signal is lower than 0V - 0.7V = -0.7V, D2 conducts forward, clamping the lower limit of the signal at -0.7V. The final output target analog voltage signal has a stable amplitude between -0.7V and 4V. In practical applications, the effective signal range can be adapted to the 0~3.3V sampling range of the ADC unit by adjusting the reference voltage (such as 3.3V), ensuring that the signal is distortion-free and safe.

[0054] By adopting the above technical solution, the signal output module 4 achieves "signal buffering + voltage clamping": the second voltage follower VF2 ensures the output terminal has the load-carrying capacity and reduces the impact of the subsequent ADC unit on the signal; the limiting circuit clamps the upper limit of the target analog voltage signal to the reference voltage (such as 3.3V) and the lower limit to the ground voltage (0V) through the reverse series diodes (D1, D2), preventing overvoltage damage to the ADC unit, while ensuring that the output signal amplitude is stable within the preset range, solving the problem of no protection and signal amplitude exceeding the limit in traditional output circuits, and providing a safe and reliable analog signal for digital sampling.

[0055] Reference Figure 3 In one embodiment, the argon arc welding pulse signal processing circuit performs the following... Figure 3 The welding pulse signal processing method shown includes the following steps:

[0056] S1. Signal Extraction: Convert the pulse electrical signal output by the welding machine into an initial analog voltage signal associated with the characteristics of the pulse electrical signal;

[0057] Specifically, step S1 includes: S11, using a Hall sensor to induce and transform the pulse electrical signal output by the welding machine, converting the high-voltage pulse signal into a low-voltage sampling current signal within a preset range;

[0058] S12. The weak current sampling signal is converted into an initial analog voltage signal through an impedance conversion circuit. The amplitude of the initial analog voltage signal is linearly related to the amplitude of the weak current sampling signal, and the initial analog voltage signal retains the periodic characteristics and amplitude variation characteristics of the pulse electrical signal.

[0059] Reference Figure 2 In one embodiment, the specific execution process of step S1 is as follows: First, in S11, a Hall sensor is used to perform non-contact inductive transformation on the primary side high-voltage pulse signal output by the welding machine (such as the kilovolt-level arc voltage signal at the transformer input), linearly converting it into a weak current sampling signal of 0-25 mA. Then, in S12, the aforementioned 0-25 mA weak current sampling signal is connected to an impedance conversion circuit. This impedance conversion circuit uses a 200-ohm precision resistor as the core conversion element, and linearly converts the current signal into an initial analog voltage signal of 0-5 volts according to Ohm's law (U=I×R). In practical applications, the 200-ohm resistor is selected as a low-temperature drift metal film resistor (e.g., accuracy ±0.1%, temperature drift ≤5ppm / ℃) to ensure that the current-voltage conversion relationship maintains a stable linear characteristic under temperature fluctuations during the welding process, reducing signal conversion errors caused by resistor value drift.

[0060] S2, Signal Processing: Filter, adjust amplitude, electrically isolate and limit voltage of the initial analog voltage signal, and output the target analog voltage signal that meets the preset parameter range;

[0061] Specifically, step S2 includes:

[0062] S21. Filtering: The initial analog voltage signal is filtered using an RC circuit to remove high-frequency noise above the preset cutoff frequency and retain the fundamental frequency characteristics of the pulse signal.

[0063] S22, Amplitude Adjustment: The analog voltage signal in the intermediate stage before or after filtering is amplified and scaled by the first amplifier OP1, the second amplifier OP2, the first voltage divider resistor network and the second voltage divider resistor network, so that the signal amplitude is adapted to the input range of the subsequent processing circuit.

[0064] S23. Electrical isolation: A linear optocoupler OC is used to perform electrical isolation processing on the amplitude-adjusted analog voltage signal to realize signal isolation transmission between the high-voltage circuit and the low-voltage control circuit.

[0065] S24. Voltage Limiting: The voltage clamping circuit clamps the isolated analog voltage signal to ensure that the output analog voltage signal is compatible with the sampling requirements and the amplitude is limited to a preset safe range to meet the input requirements of the subsequent analog-to-digital conversion circuit.

[0066] In one embodiment, the specific execution process of step S2 is as follows: First, before the filtering process in S21, step S22 amplitude adjustment is performed. The initial analog voltage signal (0-5V) is divided by the first voltage divider resistor network, and the basic analog voltage is output as approximately 0-2.5V. Then, an operational amplifier is used to build a first voltage follower VF1. The core function of the voltage follower is to increase the signal output capability, prevent the subsequent circuit load from interfering with the previous signal extraction stage, and ensure the stability of the basic analog voltage signal. With the goal of enhancing the load capacity, it adapts to the initial amplitude range of different welding machine pulse signals. Then, the filtering process in S21 is performed. An RC component filter unit is used, and its cutoff frequency is set to 723Hz. The filter only allows signals below 723Hz to pass through, effectively filtering out electromagnetic interference generated by high-frequency arc ignition in the welding environment and high-frequency noise of the circuit itself. Then, step S22 amplitude adjustment is performed again. The first amplifier OP1 amplifies the amplitude of the filtered signal, with the amplification factor controlled at 4 times for signal buffering, and finally outputs a DC voltage signal of 0-10V. The values ​​of the 723Hz cutoff frequency and the 4x amplification factor were selected through multiple experiments to ensure that the fundamental frequency characteristics of the welding pulse signal (usually below 723Hz) are fully preserved, while preventing additional signal distortion introduced by the amplification factor, thus balancing noise suppression and signal fidelity. After amplification, the signal is divided by a second voltage divider resistor network. The second voltage divider resistor network is built with resistors. If the amplified signal is 0-10V, the attenuation ratio is adjusted to 1 / 50. After voltage division, the first intermediate analog voltage signal with an amplitude of 0.0~200mV is output. The core purpose of attenuation is to adapt to the input range of the subsequent isolation circuit, prevent excessively high amplitude signals from exceeding the working threshold of the isolation components, and ensure the stability of the isolation stage. Then, the process proceeds to step S23, electrical isolation. A linear optocoupler OC is used to perform electrical isolation processing on the first intermediate analog voltage signal after amplitude adjustment, realizing signal isolation transmission between the high-voltage circuit and the low-voltage control circuit. The linear optocoupler OC has an 8x amplification function. Utilizing the linear transmission characteristics of the linear optocoupler OC, the signal is amplified by 8 times, and finally the second intermediate analog voltage signal of 0-1.6V is output.The isolation function of the linear optocoupler OC can physically separate the high-voltage welding circuit from the low-voltage control circuit, fundamentally solving the anti-interference problem of the sampling system caused by high-frequency arc ignition, preventing high-voltage fluctuations from being transmitted to the low-voltage control terminal through the signal link, and ensuring the safety of subsequent circuits and equipment. After isolation is completed, step S22 is executed again to adjust the amplitude. The isolated signal of 0-1.6V is amplified by 2 times through the second amplifier OP2 to obtain an analog voltage signal of 0-3.2V, so that the signal amplitude is accurately matched to the input range of the analog-to-digital conversion circuit 31. Finally, step S24 voltage limiting processing is executed. A limiting circuit is built using diodes to clamp and protect the 0-3.2V voltage signal, ensuring that the amplitude of the output signal is always stable within the 0-3.2V range. Finally, the target analog voltage signal is output to the ADC function pin of the microcontroller, providing a safe and stable signal source for subsequent digital processing.

[0067] Understandably, by adopting the above technical solutions, multi-step signal processing achieves "noise suppression + amplitude adaptation + safety isolation + voltage protection": the pre-processing of the voltage follower lays a stable foundation for the entire signal conditioning process, preventing load interference from affecting the signal essence; the active low-pass filter with a 723Hz cutoff frequency accurately filters out high-frequency noise, and the 4x amplification ensures that the pulse fundamental frequency characteristics are not lost, solving the problem of "incomplete noise filtering and signal distortion" in traditional filtering; the combined amplitude adjustment of "amplification + voltage division" enhances the signal driving capability through amplification and achieves unified adaptation of signals with different initial amplitude values ​​through attenuation adaptation isolation circuits; the electrical isolation of the linear optocoupler OC blocks strong electrical interference, significantly improving anti-interference capability compared to traditional common ground design; the diode limiting circuit firmly clamps the signal within the safe range of 0-3.2V, accurately matching the input threshold of the microcontroller ADC (usually 0-3.3V), preventing overvoltage damage to the ADC pins. The entire process can be flexibly adapted to the pulse signal parameters of different welding machines to cope with the complex electromagnetic environment in scenarios such as argon arc welding, ensuring the accuracy and reliability of standard analog sampling signals.

[0068] S3. Digital Processing and Feature Extraction: The standard analog sampling signal is converted from analog to digital to generate a digital signal. The digital signal is filtered, sequence analyzed, and extreme value identified by software algorithms. The peak and trough feature values ​​of the pulse electrical signal are extracted, and the feature signal that can be used for welding synchronization control is output.

[0069] Specifically, step S3 includes:

[0070] S31, Analog-to-Digital Conversion: The target analog voltage signal is converted into a digital signal through an analog-to-digital conversion circuit (not shown in the ADC diagram) with a preset number of bits. The reference voltage of the analog-to-digital conversion circuit is adapted to the preset parameter range of the target analog voltage signal (standard analog sampling signal).

[0071] S32. Digital Filtering: A software low-pass filtering algorithm is used to smooth the digital signal. The filtering period of the software low-pass filtering algorithm is matched with the sampling period to suppress residual noise.

[0072] S33, Sequence Analysis: Continuously acquire digital signals according to a preset sampling period and store them in a data buffer; sort the continuous data sequence in the buffer.

[0073] S34. Extreme value identification: Extract the maximum and minimum values ​​from the sorted digital signal sequence and use them as the peak and trough characteristic values ​​of the pulse electrical signal, respectively. S35. Characteristic signal output: Determine the validity of the peak and trough characteristic values, and use the peak and trough characteristic signals within the preset threshold range as the reference signals for welding synchronization control.

[0074] In one embodiment, step S3 is performed as follows:

[0075] First, the S31 analog-to-digital conversion is performed: the 0-3.2V standard analog sampling signal output from step S2 is converted using a 12-bit analog-to-digital converter (ADC) circuit. The reference voltage of the ADC circuit is set to 3.3V, which is highly compatible with the preset range of 0-3.2V of the standard analog sampling signal. This maximizes the utilization of the quantization range of the 12-bit ADC (quantization accuracy of approximately 0.81mV), and finally converts the analog signal into the corresponding hexadecimal digital value, ensuring the accuracy of the conversion result.

[0076] Next, the S32 digital filtering stage begins: First, a software averaging filter algorithm is used to calculate the average value of 100 consecutive digital signals after ADC conversion, initially suppressing random noise. Then, the average-filtered digital signals are sequentially input into a software low-pass filter algorithm. The filtering period of this algorithm is equal to the sampling period, set to 1ms. The cutoff frequency corresponds to a period of 0.2ms, and a filtering formula with a scaling factor of 9:1 is used. The software low-pass filter algorithm formula is: Y(n) = 0.9 × Y(n-1) + 0.1 × X(n), where Y(n) is the current output value, Y(n-1) is the previous output value, and X(n) is the current input value. After normalization, the output is a smoothed digital signal, further eliminating residual high-frequency noise and reducing noise interference with subsequent feature extraction.

[0077] Then, the S33 sequence analysis is performed: smoothed digital signals are continuously acquired according to a preset sampling period of 1ms and stored successively in the data buffer. When the buffer is full of data for 20 sampling periods (corresponding to a total duration of 200ms), the acquisition is stopped and sorting is started. Based on the matching of the buffer capacity (20 groups) and the pulse frequency (50Hz~100Hz), the 20 groups of digital data in the buffer are arranged in ascending or descending order through the bubble sort algorithm, breaking the influence of random errors that may exist in a single sampling on the data sequence, and providing a stable data foundation for subsequent extreme value identification.

[0078] Then, S34 extreme value identification is performed: the maximum and minimum values ​​are directly extracted from the 20 sets of data after bubble sorting, and used as the peak feature value and trough feature value of the welding pulse electrical signal, respectively, to achieve accurate capture of the core features of the pulse signal;

[0079] Finally, the S35 characteristic signal output is executed: Peak and trough characteristic values ​​are extracted using a software algorithm for validity assessment. These values ​​are compared with preset amplitude limits (e.g., upper and lower peak thresholds set according to the welding machine's rated parameters). If the characteristic value is within the preset threshold range, it is considered normal data, and the peak and trough characteristic signals are directly output as reference signals for welding synchronization control. If the characteristic value exceeds the preset threshold range (e.g., peak too high, trough too low), it is considered over-limit data, and the system immediately triggers a warning alarm (e.g., outputting alarm information through the human-machine interface unit), while simultaneously pausing the characteristic signal output to prevent abnormal data from causing errors in motor synchronization control. Preferably, the preset thresholds are set according to the welding machine's rated pulse parameters, such as peak threshold = rated peak voltage × 90%, trough threshold = rated trough voltage × 110%.

[0080] Understandably, digital processing achieves "precise conversion + noise suppression + feature extraction": analog-to-digital conversion (such as 3.3V reference, 12-bit ADC) converts analog signals into digital signals, ensuring conversion accuracy; software low-pass filtering (such as 1ms period, 9:1 scaling factor algorithm) further smooths residual noise; data buffering for 20 sampling periods and bubble sorting can avoid single sampling errors; extreme value identification accurately extracts peak / trough values, combined with validity judgment (over-limit alarm), outputting a reliable control reference signal, solving the problems of inaccurate feature extraction and susceptibility to interference in traditional signal processing, and providing accurate basis for motor synchronous control.

[0081] By adopting the above technical solution, this method addresses the problems existing in TIG welding pulse signal sampling, such as numerical instability (e.g., fluctuations in welding machine positive and negative electrode voltage sampling), signal distortion caused by high-frequency arc ignition interference, and inaccurate capture of peak / trough feature values. It constructs a solution based on "full-process signal optimization + precise feature extraction," providing reliable data support for subsequent arc voltage tracking and motor synchronization control. On the one hand, the filtering, amplitude adjustment, and electrical isolation steps in signal processing can specifically filter out high-frequency noise in the welding environment, optimize signal amplitude adaptability, and block high-frequency arc ignition interference. On the other hand, the signal extraction stage, through its design adapted to high-voltage conversion, provides a basis for subsequent introduction of specialized... The use of components lays the foundation for strong and weak current isolation, solving the problem of traditional direct sampling being susceptible to strong current impact. The digital processing stage further smooths the signal through software filtering, and the sequence analysis and extreme value identification accurately locate peaks / troughs, solving the problem of large feature value deviations caused by excessive interference and rough processing in traditional sampling. The overall process ensures that the characteristics of the pulse signal (period and amplitude changes) are completely preserved, and improves the signal stability and feature extraction accuracy through multi-stage processing. Compared with the existing switch threshold control method, it can reflect the dynamic changes of the pulse signal more delicately, providing key data support for simulating the manual techniques of welding experts and realizing linear arc voltage control and synchronous motor adjustment.

[0082] This application also discloses a welding apparatus, including a welding machine, a wire feeding motor, a walking motor, an argon arc welding pulse signal processing circuit as described in any of the above embodiments, an ADC unit, a microcontroller control module, and other hardware, and is equipped with a pulse filtering algorithm and a multi-motor synchronous control program.

[0083] Understandably, by adopting the above technical solution, the welding device integrates a dedicated argon arc welding pulse signal processing circuit. Compared with traditional devices that are not equipped with precise signal processing circuits, it can achieve safe and precise processing of high-voltage pulse signals in argon arc welding pulse welding. On the one hand, the circuit, through transient suppression and electrical isolation designs, prevents the high voltage and high-frequency interference of the welding machine from affecting the control loop, thereby improving the safety and stability of the device. On the other hand, after filtering, amplitude adjustment, and limiting, the target analog sampling signal adapted to the sampling requirements can be directly adapted to the ADC unit and control module in the device, providing a high-quality signal reference for the synchronous control of the wire feeding motor and the walking motor. This ensures that the motor action and the welding pulse cycle are precisely matched, reducing the waste of consumables caused by ineffective wire feeding and lowering the weld defect rate. It is especially suitable for argon arc welding pulse welding scenarios with stringent requirements for welding precision and reliability, such as the nuclear power field, while also improving the overall anti-interference capability and signal processing efficiency of the device.

[0084] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A pulse signal processing circuit for argon arc welding, characterized in that, include: The signal input module (1), signal processing module (2), signal isolation module (3), and signal output module (4) are connected in series. The signal input module (1) is used to acquire the pulse electrical signal output by the welding machine and convert the pulse electrical signal into a basic analog voltage signal associated with the characteristics of the pulse electrical signal. The signal input module (1) includes: transient suppression diode ZD, input resistor R0, Zener diode D0 and first voltage divider resistor network; One end of the transient suppression diode ZD is connected to the welding machine pulse signal, and the other end is connected to the input resistor R0. The Zener diode D0 is connected in parallel between the output terminal of the input resistor R0 and ground. The positive terminal of the Zener diode D0 is grounded, and the negative terminal is connected to the output terminal of the input resistor R0. The output terminal of the input resistor R0 is connected to the input terminal of the first voltage divider resistor network. The first voltage divider resistor network is connected between ground and the input resistor R0 and includes a first resistor R1 and a second resistor R2 connected in series. The connection point of the first resistor R1 and the second resistor R2 is the output terminal, which is used to output the basic analog voltage signal. The signal processing module (2) is used to filter and adjust the amplitude of the basic analog voltage signal to generate a first intermediate analog voltage signal; The signal isolation module (3) is used to perform electrical isolation processing on the first intermediate analog voltage signal, form an isolated transmission of the high-voltage and low-voltage circuits, and generate a second intermediate analog voltage signal; The signal output module (4) is used to limit the voltage of the second intermediate analog voltage signal and output a target analog voltage signal that meets the preset parameter range.

2. The argon arc welding pulse signal processing circuit according to claim 1, characterized in that, The first voltage divider resistor network also includes an eleventh resistor R11 and a twelfth resistor R12, wherein the eleventh resistor R11 is connected in parallel with the first resistor R1, and the twelfth resistor R12 is connected in parallel with the second resistor R2.

3. The argon arc welding pulse signal processing circuit according to claim 1, characterized in that, The signal processing module (2) includes a first voltage follower VF1, a low-pass filter circuit, and a second voltage divider resistor network connected in series. The input terminal of the first voltage follower VF1 is connected to the basic analog voltage signal, and the output terminal is connected to the low-pass filter circuit. The low-pass filter circuit includes an RC circuit and a first amplifier OP1. The RC circuit is connected to the non-inverting input of the first voltage follower VF1 and the first amplifier OP1. A third resistor R3 is connected between the inverting input and output of the first amplifier OP1. The third resistor R3 is used to set the amplification factor. The second voltage divider resistor network includes a fourth resistor R4, a fifth resistor R5, and a sixth resistor R6 connected in series between the output terminal of the first amplifier OP1 and ground. The fourth resistor R4 is connected to the output terminal of the first amplifier OP1, the sixth resistor R6 is grounded, and the connection point of the fifth resistor R5 and the sixth resistor R6 is the output terminal, used to output a first intermediate analog voltage signal.

4. The argon arc welding pulse signal processing circuit according to claim 3, characterized in that, The low-pass filter circuit has a cutoff frequency of 723Hz and an amplification factor of 4.

5. The argon arc welding pulse signal processing circuit according to claim 1, characterized in that, The signal isolation module (3) includes a linear optocoupler OC and a second amplifier OP2 connected in series. The primary side of the linear optocoupler OC receives the first intermediate analog voltage signal, and the secondary side is connected to the non-inverting input terminal and the inverting input terminal of the second amplifier OP2 for amplifying the first intermediate analog voltage signal. A seventh resistor R7 is provided between the inverting input terminal and the output terminal of the second amplifier OP2. The output terminal of the second amplifier OP2 is used to output the second intermediate analog voltage signal.

6. The argon arc welding pulse signal processing circuit according to claim 5, characterized in that, The linear optocoupler OC secondary side includes a first output pin and a second output pin. The first output pin is connected to the non-inverting input of the second amplifier OP2 via an eighth resistor R8, and the second output pin is connected to the inverting input of the second amplifier OP2 via a ninth resistor R9. The eighth resistor R8 and the ninth resistor R9 are used for current limiting and impedance matching.

7. The argon arc welding pulse signal processing circuit according to claim 5, characterized in that, The second intermediate analog voltage signal is amplified 16 times relative to the first intermediate analog voltage signal.

8. The argon arc welding pulse signal processing circuit according to claim 1, characterized in that, The signal output module (4) includes a second voltage follower VF2 and a limiting circuit; The limiting circuit includes a first diode D1 and a second diode D2 connected in reverse series. The positive terminal of the first diode D1 is connected to a reference voltage, and the negative terminal of the second diode D2 is grounded. The connection point of the first diode D1 and the second diode D2 forms a common node. The input terminal of the second voltage follower VF2 is connected to the second intermediate analog voltage signal, and the output terminal is connected to the common node. The common node serves as the output terminal of the limiting circuit for outputting the target analog voltage signal.

9. A welding apparatus, characterized in that, Includes the argon arc welding pulse signal processing circuit as described in any one of claims 1-8.

Images