Circuit and method for setting current and voltage of welding machine by robot controller

Abstract

The invention provides a circuit and method for a robot controller to set current and voltage of a welding machine, and the circuit for the robot controller to set the current and voltage of the welding machine comprises a main control module which is used for outputting a PWM signal; the input end of the optocoupler isolation module is connected with the output end of the main control module, and the optocoupler isolation module is used for isolating the PWM signals output by the optocoupler isolation module; the input end of the signal conversion module is connected with the output end of the optocoupler isolation module, and the signal conversion module is used for converting the PWM signal output by the optocoupler isolation module into an analog signal; the input end of the operational amplification module is connected with the output end of the signal conversion module, analog signals output by the signal conversion module enter the operational amplification module in a differential input mode, and the operational amplification module conducts buffering isolation and signal conditioning on the analog signals.

Description

Technical Field

[0001] The invention relates to the technical field of automated welding, in particular to a circuit and method for a robot controller to set a welding machine current and voltage. Background Art

[0002] In the automated welding system, controlling the voltage and current during the welding process is a key factor in ensuring welding quality and stability. Currently, many welding robot systems use 0-10V analog signals to control the welding voltage and current of the welding machine. This control method is widely used in different types of welding processes due to its simplicity and adaptability. It can achieve real-time control of current and voltage through simple voltage regulation, thus meeting the basic needs of most welding processes.

[0003] In related technologies, many controller CPUs do not directly support analog output and need to use interfaces such as SPI and I2C to achieve analog signal conversion. These interface conversion chips are expensive and require supporting peripheral components, which increases the overall cost and software workload. In addition, traditional technologies also have insufficient anti-interference ability and response speed in complex electromagnetic environments, making it difficult to meet the needs of high-precision and high-reliability welding. Summary of the invention

[0004] In view of the above problems, in a first aspect, an embodiment of the present invention provides a circuit for a robot controller to set a welding machine current and voltage, the circuit for a robot controller to set a welding machine current and voltage comprises: a main control module, the main control module is used to output a PWM signal;

[0005] An optocoupler isolation module, wherein the input end of the optocoupler isolation module is connected to the output end of the main control module, and the optocoupler isolation module is used to isolate the PWM signal output by the optocoupler isolation module;

[0006] A signal conversion module, the input end of the signal conversion module is connected to the output end of the optocoupler isolation module, and the signal conversion module is used to convert the PWM signal output by the optocoupler isolation module into an analog signal;

[0007] An operational amplifier module, wherein the input end of the operational amplifier module is connected to the output end of the signal conversion module, the analog signal output by the signal conversion module enters the operational amplifier module through a differential input, and the operational amplifier module performs buffering, isolation and signal conditioning on the analog signal.

[0008] In one embodiment, the optical coupling isolation module includes an optical coupler U3 and an optical coupler U5, and the input ends of the optical coupler U3 and the optical coupler U5 are respectively connected to two output ends of the main control module for outputting PWM signals.

[0009] In one embodiment, the signal conversion module includes a signal conversion chip U2 and a signal conversion chip U6, the input end of the signal conversion chip U2 is connected to the output end of the optocoupler U3, and the input end of the signal conversion chip U6 is connected to the output end of the optocoupler U5.

[0010] In one embodiment, the operational amplifier module includes an operational amplifier U4A and an operational amplifier U4B, the input end of the operational amplifier U4A is connected to the output end of the signal conversion chip U2, and the input end of the operational amplifier U4B is connected to the output end of the signal conversion chip U6.

[0011] In one embodiment, the circuit for setting the welding machine current and voltage by the robot controller further includes a capacitor C13, a capacitor C25, a transient voltage suppression diode D2, and a transient voltage suppression diode D3. The capacitor C13 and the transient voltage suppression diode D2 are connected in parallel to the output end of the operational amplifier U4A, and the capacitor C25 and the transient voltage suppression diode D3 are connected in parallel to the output end of the operational amplifier U4B.

[0012] In one embodiment, the circuit for setting the welding machine current and voltage by the robot controller also includes: a power supply module, which is respectively connected to the signal conversion module and the operational amplifier module, and is used to convert the voltage and provide power to the signal conversion module and the operational amplifier module.

[0013] A second aspect of the present application further provides a method for a robot controller to set a welding machine current and voltage, the method being applied to the circuit for a robot controller to set a welding machine current and voltage as described in the above aspect, the method comprising:

[0014] Receive the voltage value input by the user;

[0015] According to the received input voltage value, the corresponding PWM signal duty cycle is calculated and a PWM signal is generated;

[0016] The generated PWM signal is isolated by an optical coupling isolation module and then transmitted to a signal conversion module, and the signal conversion module generates a corresponding analog voltage signal according to the received PWM signal;

[0017] The analog voltage signal output by the signal conversion module is buffered, isolated and signal conditioned by the operational amplifier module to output a stable analog voltage signal.

[0018] In one embodiment, the method further comprises:

[0019] The analog voltage signal output by the operational amplifier module is transmitted to the input end of the welding machine and is used as the current or voltage given signal of the welding machine;

[0020] After receiving the current or voltage given signal, the welding machine sets the corresponding welding current or voltage and performs welding.

[0021] In one embodiment, the method further comprises:

[0022] After the welding machine receives the current or voltage given signal, the current welding current or voltage is displayed on the welding machine LED panel.

[0023] In one of the embodiments, the frequency of the PWM signal is fixed at 1 KHz, and the duty cycle is linearly related to the input voltage. The input voltage range is 0V to 10V, and the duty cycle range is 0% to 100%.

[0024] The above one or more technical solutions in the embodiments of the present application have at least one or more of the following technical effects:

[0025] The present invention proposes a circuit for setting the current and voltage of a welding machine by a robot controller, comprising a main control module, an optical coupling isolation module, a signal conversion module and an operational amplifier module. The main control module outputs two PWM signals, which are isolated by the optical coupling isolation module. The optical coupling isolation module can maintain the waveform and frequency characteristics of the PWM signal, effectively isolate the electrical connection between the input and output circuits, and prevent interference and noise propagation. At the same time, the optical coupling isolation module isolates the PWM signal, avoids the influence of electromagnetic interference on the PWM signal, and ensures the integrity of the signal during transmission. The signal conversion module converts the isolated PWM signal into an analog signal, and the analog signal enters the operational amplifier module by differential input. The operational amplifier module performs buffer isolation and signal conditioning on the signal, so that the signal driving ability is enhanced, and has a good inhibitory effect on the signal attenuation problem over a long distance. The differential input can effectively reduce the error of the signal source itself. When there is a slight voltage fluctuation in the analog signal, the differential input can eliminate the influence of such fluctuation, thereby improving the accuracy and stability of the signal. The output stage of the operational amplifier module can provide a larger current output, which greatly enhances the driving ability of the capacitive load. Thus, the accurate setting of the current and voltage of the welding machine is achieved. The hardware connection of this solution is simple. The main control module only needs to output PWM signals to realize analog voltage signal conversion, without occupying interfaces such as SPI and I2C, saving costs and software workload. The duty cycle of the PWM signal can be quickly changed in the main control module. Compared with communication interfaces based on complex protocols such as SPI or I2C, data processing is simpler and the response is faster.

[0026] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 A schematic diagram of a circuit module of a circuit for setting welding machine current and voltage in a robot controller in an embodiment of the present invention;

[0029] Figure 2 A schematic diagram of the circuit principle of a circuit for setting welding machine current and voltage in a robot controller in an embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of the circuit principle of a power module of a circuit for setting welding machine current and voltage in a robot controller in an embodiment of the present invention.

[0031] Description of reference numerals: 100, main control module; 200, optical coupling isolation module; 300, signal conversion module; 400, operational amplifier module; 500, welding machine. DETAILED DESCRIPTION

[0032] The overall idea of ​​the technical solution provided by the present invention is as follows:

[0033] See also Figure 1 The circuit used for the robot controller to set the welding machine current and voltage includes:

[0034] The main control module 100 is used to output a PWM signal; specifically, the main function of the main control module 100 is to generate a PWM (pulse width modulation) signal for controlling the current and voltage of the welding machine 500. The main control module 100 calculates the corresponding PWM signal duty cycle through an internal algorithm based on the voltage value input by the user, and generates two PWM signals. It can be understood that the main control module 100 is usually composed of a microcontroller (such as an STM32 series single-chip microcomputer) or a PLC (programmable logic controller). The PWM signal generated by the main control module 100 is output through the output end of the main control module 100, and then transmitted to the optocoupler isolation module 200 for isolation.

[0035] Optocoupler isolation module 200, the input end of the optocoupler isolation module 200 is connected to the output end of the main control module 100, and the optocoupler isolation module 200 is used to isolate the PWM signal output by the optocoupler isolation module 200; it can be understood that the optocoupler isolation module 200 is an electronic component that uses optical signals to achieve electrical isolation. Its main principle is to achieve signal isolation between the input end and the output end through photoelectric conversion between a light emitting diode (LED) and a photosensitive transistor (phototransistor). When the input signal is added to the LED, the LED will emit a light signal, which is received by the photosensitive transistor after isolation and converted into an electrical signal output. Since there is no direct electrical connection between the light emitting diode and the photosensitive transistor, electrical isolation between circuits can be achieved to prevent interference and noise propagation. The optocoupler isolation module 200 can well maintain the waveform and frequency characteristics of the PWM signal to ensure the integrity of the signal during transmission. The optocoupler isolation module 200 has a high common mode rejection ratio and can effectively suppress common mode interference signals. The optocoupler isolation module 200 uses optical signals for transmission, is not interfered by electromagnetic fields and electromagnetic waves, and has strong anti-interference ability.

[0036] The signal conversion module 300, the input end of the signal conversion module 300 is connected to the output end of the optocoupler isolation module 200, and the signal conversion module 300 is used to convert the PWM signal output by the optocoupler isolation module 200 into an analog signal; the core function of the signal conversion module 300 is to linearly convert the PWM (pulse width modulation) signal into a corresponding analog voltage signal. Specifically, the signal conversion module 300 converts the input PWM signal into an analog voltage signal output that is linearly related to the duty cycle of the input PWM signal. For example, the signal conversion module 300 first detects the duty cycle of the input PWM signal, and then linearly converts it into a corresponding analog voltage signal based on the detected duty cycle. For example, a PWM signal with a duty cycle of 50% will be converted into an analog voltage signal of 5V.

[0037] Operational amplifier module 400, the input end of operational amplifier module 400 is connected to the output end of signal conversion module 300, the analog signal output by signal conversion module 300 enters operational amplifier module 400 through differential input, and operational amplifier module 400 performs buffering isolation and signal conditioning on the analog signal. Specifically, the differential input method amplifies the signal by comparing the difference between two input signals (positive phase input and negative phase input) instead of directly amplifying a single signal, which can effectively reduce the error of the signal source itself, such as noise, drift and common mode interference. Operational amplifier module 400 has the characteristics of high input impedance and low output impedance, which can achieve signal buffering isolation, thereby enhancing the driving ability of the signal and preventing the signal from being affected by the load during transmission.

[0038] In summary, the present application provides a circuit for setting the current and voltage of a welding machine by a robot controller, comprising: a main control module 100, an optical coupling isolation module 200, a signal conversion module 300 and an operational amplifier module 400. The main control module 100 outputs two PWM signals, which are isolated by the optical coupling isolation module 200. The optical coupling isolation module 200 can maintain the waveform and frequency characteristics of the PWM signal, effectively isolate the electrical connection between the input and output circuits, and prevent interference and noise propagation. At the same time, the optical coupling isolation module 200 isolates the PWM signal, avoids the influence of electromagnetic interference on the PWM signal, and ensures the integrity of the signal during transmission; The signal conversion module 300 converts the isolated PWM signal into an analog signal, and the analog signal enters the operational amplifier module 400 through differential input. The operational amplifier module 400 performs buffer isolation and signal conditioning on the signal, so that the signal driving ability is enhanced, and has a good inhibitory effect on the signal attenuation problem over a long distance. The differential input can effectively reduce the error of the signal source itself. When there is a slight voltage fluctuation in the analog signal, the differential input can eliminate the influence of such fluctuation, thereby improving the accuracy and stability of the signal. The output stage of the operational amplifier module 400 can provide a larger current output, which greatly enhances the driving ability of the capacitive load. Thus, the current and voltage of the welding machine 500 can be accurately set. The hardware connection of this solution is simple. The main control module 100 only needs to output the PWM signal to realize the analog voltage signal conversion, without occupying the SPI, I2C and other interfaces, saving costs and software workload. The duty cycle of the PWM signal can be quickly changed in the main control module 100. Compared with the communication interface based on complex protocols such as SPI or I2C, the data processing is simpler and the response is faster.

[0039] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] See also Figure 2The optocoupler isolation module 200 includes an optocoupler U3 and an optocoupler U5. The input ends of the optocoupler U3 and the optocoupler U5 are respectively connected to the two output ends of the main control module 100 for outputting PWM signals. Specifically, the main control module 100 generates two PWM signals, which are isolated and transmitted through the optocoupler U3 and the optocoupler U5 respectively. The optocoupler U3 and the optocoupler U5 are the core components of the optocoupler isolation module 200, which are responsible for realizing the electrical isolation and transmission of the signal. The optocoupler U3 and the optocoupler U5 can usually adopt high-speed optocouplers, such as the optocoupler of model ELM611, which has a response time of nanoseconds and can respond to changes in the input PWM signal more quickly. It has a high transmission rate, strong anti-interference ability, and a high common-mode rejection ratio. It can effectively suppress common-mode interference signals, ensure the stability and reliability of signal transmission, and ensure its use in the complex electromagnetic environment of welding.

[0041] See also Figure 2 The signal conversion module 300 includes a signal conversion chip U2 and a signal conversion chip U6. The input end of the signal conversion chip U2 is connected to the output end of the optocoupler U3, and the input end of the signal conversion chip U6 is connected to the output end of the optocoupler U5. For example, the signal conversion chip U2 and the signal conversion chip U6 can use a signal conversion chip of model GP8101. GP8101 is a high-performance PWM signal to analog signal conversion chip with high precision, fast response and wide applicability. The PWM signal isolated by the optocoupler U3 and the optocoupler U5 is input to the input end of the signal conversion chip U2 and the signal conversion chip U6 respectively. According to the detected duty cycle of the PWM signal, the signal conversion chip U2 and the signal conversion chip U6 linearly convert it into a corresponding analog voltage signal.

[0042] See also Figure 2The operational amplifier module 400 includes an operational amplifier U4A and an operational amplifier U4B. The input end of the operational amplifier U4A is connected to the output end of the signal conversion chip U2, and the input end of the operational amplifier U4B is connected to the output end of the signal conversion chip U6. The operational amplifier U4A and the operational amplifier U4B are the core components of the operational amplifier module 400, which are responsible for buffering, isolating, signal conditioning and amplifying the input analog signal. The operational amplifier U4A and the operational amplifier U4B usually adopt high-precision operational amplifiers, such as TI's OPA series, Analog Devices' AD series, etc. The analog voltage signals converted by the signal conversion chip U2 and the signal conversion chip U6 are respectively input to the input ends of the operational amplifier U4A and the operational amplifier U4B. The voltage range of the analog voltage signal is usually 0V to 5V or 0V to 10V, depending on the design of the signal conversion module 300. The output ends of the operational amplifiers U4A and U4B are respectively connected to the two input ends of the control circuit of the welding machine 500, and the processed analog voltage signals are output to the control circuit of the welding machine 500 for controlling the current and voltage of the welding machine 500.

[0043] See also Figure 2 , a circuit for setting the current and voltage of the welding machine by the robot controller, further comprising capacitor C13, capacitor C25, transient voltage suppression diode D2, transient voltage suppression diode D3, capacitor C13 and transient voltage suppression diode D2 are connected in parallel to the output end of the operational amplifier U4A, and capacitor C25 and transient voltage suppression diode D3 are connected in parallel to the output end of the operational amplifier U4B. Specifically, capacitor C13 and capacitor C25 have low impedance characteristics for high-frequency noise and ripple, and can effectively filter out these unwanted signal components. By filtering, the fluctuation of the output voltage is reduced, and the signal is more stable, which is very important for precision control applications. When a transient voltage spike appears at the output end, transient voltage suppression diodes D2 and transient voltage suppression diodes D3 will quickly turn on and clamp the overvoltage to a safe level (for example, the breakdown voltage of the transient voltage suppression diode). This protection mechanism can prevent transient voltage spikes from damaging the operational amplifier module 400 and other sensitive circuits.

[0044] Furthermore, the circuit for setting the welding machine current and voltage by the robot controller also includes: a power module, which is connected to the signal conversion module 300 and the operational amplifier module 400 respectively, and is used to convert the voltage and supply power to the signal conversion module 300 and the operational amplifier module 400. Specifically, the main function of the power module is to convert the input power supply voltage into the voltage level required by the signal conversion module 300 and the operational amplifier module 400, for example, to convert the input 12V or 24V power supply into 5V or ±15V and other voltages to meet the working voltage requirements of different modules.

[0045] See also Figure 3 The power module includes a DC-DC converter U1, which is used to convert the input DC voltage into the DC voltage required by the signal conversion module 300 and the operational amplifier module 400. The DC-DC converter U1 can use a DC-DC converter of the B2415LS series. The B2415LS series DC-DC converter module has the characteristics of high efficiency, isolated voltage and non-regulated output, and is suitable for distributed power systems that require isolated voltage. The power module realizes voltage conversion and voltage stabilization filtering through the B2415LS series DC-DC converter U1, providing a stable power supply for the signal conversion module 300 and the operational amplifier module 400.

[0046] The present invention also provides a method for a robot controller to set a welding machine current and voltage, the method specifically comprising the following steps:

[0047] Receive the voltage value input by the user;

[0048] According to the received input voltage value, the corresponding PWM signal duty cycle is calculated and a PWM signal is generated;

[0049] The generated PWM signal is isolated by the optical coupling isolation module 200 and then transmitted to the signal conversion module 300, and the signal conversion module 300 generates a corresponding analog voltage signal according to the received PWM signal;

[0050] The analog voltage signal output by the signal conversion module 300 is buffered, isolated and signal conditioned by the operational amplifier module 400 to output a stable analog voltage signal.

[0051] Specifically, the user can input the corresponding voltage value through the human-machine interface (such as a touch screen, keyboard or control software). According to the voltage value input by the user, the main control module 100 calculates the corresponding PWM signal duty cycle through an internal algorithm and generates a corresponding PWM signal. The generated PWM signal is electrically isolated through the optical coupling isolation module 200 to prevent electrical interference and noise propagation between the main control module 100 and subsequent circuits, thereby improving the stability and reliability of the system. The signal conversion chip (such as a PWM to analog voltage chip) in the signal conversion module 300 linearly converts the PWM signal into an analog voltage signal according to the duty cycle of the PWM signal. The analog voltage signal output by the signal conversion module 300 is buffered and isolated through the operational amplifier module 400 to enhance the driving capability of the signal and prevent the signal from being affected by the load during transmission. The operational amplifier module 400 filters, amplifies and stabilizes the signal.

[0052] Furthermore, the method also includes:

[0053] The analog voltage signal output by the operational amplifier module 400 is transmitted to the input end of the welding machine 500 and is used as a current or voltage given signal of the welding machine 500;

[0054] After receiving the current or voltage setting signal, the welding machine 500 sets the corresponding welding current or voltage and performs welding.

[0055] Specifically, the analog voltage signal is used as the current or voltage setting signal of the welding machine 500 to set the specific working parameters of the welding machine. By changing the voltage value of the analog voltage signal, the different current or voltage outputs of the welding machine 500 can be adjusted to achieve precise control of the welding process. For example, there is a linear relationship between the voltage value of the analog voltage signal and the current or voltage setting value of the welding machine 500, for example: 0V corresponds to the minimum current or voltage, 10V corresponds to the maximum current or voltage, and the intermediate voltage value corresponds to the corresponding intermediate current or voltage value. When the analog voltage signal is used to control the current of the welding machine 500, the change in the voltage value will directly lead to the change in the output current of the welding machine 500. When the analog voltage signal is used to control the voltage of the welding machine 500, the change in the voltage value will directly lead to the change in the output voltage of the welding machine 500. The analog voltage signal is a voltage signal whose voltage value changes within a certain range and is used to control the current or voltage of the welding machine.

[0056] Furthermore, the method also includes:

[0057] After the welding machine 500 receives the current or voltage given signal, the current welding current or voltage is displayed on the LED panel of the welding machine 500. Specifically, the welding machine 500 is usually equipped with a current sensor for real-time monitoring of the actual welding current. Similarly, the welding machine 500 is equipped with a voltage sensor for real-time monitoring of the actual welding voltage. The current and voltage sensors transmit the collected data to the control system of the welding machine 500. The control system processes the collected data and converts it into a displayable value. The control system of the welding machine 500 sends the processed current or voltage value to the display drive circuit of the LED panel. The LED panel displays the current welding current or voltage value in real time based on the received data. The operator can monitor the welding current and voltage in real time through the LED panel to ensure that the welding process meets expectations.

[0058] Furthermore, the frequency of the PWM signal is fixed at 1KHz, and the duty cycle is linearly related to the input voltage. The input voltage range is 0V to 10V, and the duty cycle range is 0% to 100%. Specifically, there is a linear proportional relationship between the duty cycle and the input voltage, that is, the change of the input voltage directly leads to the change of the duty cycle. The formula can be expressed as: Duty cycle = (input voltage / maximum input voltage) × 100%. For example, when the input voltage is 5V, the duty cycle is 50%; when the input voltage is 10V, the duty cycle is 100%. The PWM signal achieves precise and fast control through a fixed frequency and a linear duty cycle and input voltage relationship. Its 0V to 10V input voltage range and 0% to 100% duty cycle range provide high-resolution control capabilities.

[0059] The following is an example analysis of the voltage setting process of the welding machine 500, which is intended to achieve accurate setting of the voltage of the welding machine 500 through the teach pendant, the main control module 100, the optocoupler isolation module 200, the signal conversion module 300 and the operational amplifier module 400.

[0060] If the welding current of a welding machine 500 is to be set, first, the user enters the current and voltage matching interface in the welding process setting of the teach pendant. In this interface, the user enters the voltage value corresponding to the desired current in the "Analog AO0 (V)" input box. For example, entering "1.2" means setting the welding current to 66A. Then, the user clicks the "Analog Test" button to trigger the teach pendant to send the command to the main control module 100 through the wired network. After receiving the command, the main control module 100 generates a PWM signal with a frequency of 1KHz and sets the corresponding duty cycle according to the input voltage value. For example, the input of 1.2V corresponds to a duty cycle of 12% (because 0~10V corresponds to a duty cycle of 0~100%). The PWM signal is first electrically isolated by the optocoupler isolation module 200 to prevent interference and noise propagation, and then transmitted to the input end of the signal conversion module 300. The signal conversion module 300 linearly converts the PWM signal into a 1.2V analog voltage signal, which is then buffered, isolated and signal conditioned by the operational amplifier module 400 to ensure the stability and accuracy of the signal. Finally, the stable 1.2V voltage is transmitted to the input end of the welding machine 500 through the cable as the current setting signal of the welding machine 500. After receiving the signal, the welding machine 500 sets the welding current to 66A according to the process parameters and working conditions, and displays the current current of the welding machine 500 as 66A on the LED panel.

[0061] Similarly, in the current and voltage matching interface, the user can enter a higher voltage value, for example, entering "10" means setting the welding current to 550A. After clicking the "Analog Test" button, the main control module 100 generates a PWM signal with a duty cycle of 100%, which passes through the optocoupler isolation module 200 and the signal conversion module 300, and finally outputs a 10V voltage as the current setting signal of the welding machine 500. After receiving the 10V signal, the welding machine 500 sets the welding current to 550A, and displays the current current of the welding machine 500 as 550A on the LED panel.

[0062] If you want to set the welding voltage of a welding machine 500, first, enter the desired voltage value in the "Analog AO0 (V)" input box. For example, enter "1.2" to set the welding voltage to 14.8V. Then, click the "Analog Test" button to trigger the teach pendant to send the command to the main control module 100 through the wired network. After receiving the command, the main control module 100 generates a PWM signal with a frequency of 1KHz and sets the corresponding duty cycle according to the input voltage value. For example, the duty cycle corresponding to the input of 1.2V is 12%. After the PWM signal passes through the optocoupler isolation module 200, it is input to the input end of the signal conversion module 300. The signal conversion module 300 linearly converts the PWM signal into a 1.2V analog voltage signal, and then processes it through the operational amplifier module 400, and finally outputs a stable 1.2V voltage, which is transmitted to the input end of the welding machine 500 through the cable as the voltage setting signal of the welding machine 500. After receiving the signal, the welding machine 500 sets the welding voltage to 14.8V according to the process parameters and working conditions, and displays the current welding machine 500 voltage as 14.8V on the LED panel.

[0063] Similarly, in the current and voltage matching interface, the user can enter a higher voltage value, for example, entering "9.5" means setting the welding voltage to 47.4V. After clicking the "Analog Test" button, the main control module 100 generates a PWM signal with a duty cycle of 95%, which passes through the optical coupling isolation module 200 and the signal conversion module 300, and finally outputs a 9.5V voltage as the voltage setting signal of the welding machine 500. After receiving the 9.5V signal, the welding machine 500 sets the welding voltage to 47.4V, and displays the current voltage of the welding machine 500 as 47.4V on the LED panel.

[0064] In the welding process setting, the precise control of current and voltage is achieved through the current / voltage curve. The user first enters the voltage and current matching interface. In this interface, the user needs to enter the minimum and maximum welding current values ​​of the welding machine 500, namely 66A and 550A, in the two check boxes corresponding to the X-axis (welding current) of the current / voltage curve. At the same time, enter the voltage values ​​corresponding to these current values ​​in the corresponding check boxes of the Y-axis (input analog voltage), namely 1.2V and 10V. These values ​​indicate that when a 1.2V analog voltage signal is input, the welding machine 500 needs to output a welding current of 66A; when a 10V analog voltage signal is input, a welding current of 550A needs to be output. After the input is completed, the user clicks the "Save" button and the system saves the current settings. In this way, the current setting of the welding machine 500 is completed, ensuring that the robot outputs an analog voltage of 1.2V to 10V through the PWM signal, corresponding to the control of the welding current range of the welding machine 500 to be 66A to 550A.

[0065] Similarly, the user sets the voltage of the welding machine 500 in the current / voltage curve diagram of the same interface. The user needs to enter the minimum and maximum welding voltage values ​​of the welding machine 500 in the two check boxes corresponding to the X-axis (welding current), namely 14.8V and 47.4V. At the same time, enter the voltage values ​​corresponding to these voltage values ​​in the corresponding check boxes of the Y-axis (input analog voltage), namely 1.2V and 9.5V. These values ​​indicate that when a 1.2V analog voltage signal is input, the welding machine 500 needs to output a welding voltage of 14.8V, and when a 9.5V analog voltage signal is input, the welding machine 500 needs to output a welding voltage of 47.4V. After the input is completed, the user clicks the "Save" button and the system saves the current settings. In this way, the voltage setting of the welding machine 500 is completed, ensuring that the robot outputs an analog voltage of 1.2V to 9.5V through a PWM signal, and the corresponding control welding voltage range of the welding machine 500 is 14.8V to 47.4V.

[0066] Through this precise setting process, users can ensure that the welder 500 can operate according to the expected current and voltage in different welding tasks, thereby ensuring welding quality and production efficiency.

[0067] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0068] Obviously, those skilled in the art can make various changes and modifications to the embodiments of the present invention without departing from the spirit and scope of the embodiments of the present invention. Thus, if these modifications and variations of the embodiments of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A circuit for setting welding machine current and voltage in a robot controller, characterized in that: include: A main control module, wherein the main control module is used to output a PWM signal; An optocoupler isolation module, wherein the input end of the optocoupler isolation module is connected to the output end of the main control module, and the optocoupler isolation module is used to isolate the PWM signal output by the optocoupler isolation module; A signal conversion module, the input end of the signal conversion module is connected to the output end of the optocoupler isolation module, and the signal conversion module is used to convert the PWM signal output by the optocoupler isolation module into an analog signal; An operational amplifier module, wherein the input end of the operational amplifier module is connected to the output end of the signal conversion module, the analog signal output by the signal conversion module enters the operational amplifier module through a differential input, and the operational amplifier module performs buffering, isolation and signal conditioning on the analog signal.

2. The circuit for setting welding machine current and voltage by robot controller according to claim 1, characterized in that: The optical coupling isolation module includes an optical coupler U3 and an optical coupler U5, and the input ends of the optical coupler U3 and the optical coupler U5 are respectively connected to two output ends of the main control module for outputting PWM signals.

3. The circuit for setting welding machine current and voltage by robot controller according to claim 2, characterized in that: The signal conversion module includes a signal conversion chip U2 and a signal conversion chip U6. The input end of the signal conversion chip U2 is connected to the output end of the optical coupler U3, and the input end of the signal conversion chip U6 is connected to the output end of the optical coupler U5.

4. The circuit for setting welding machine current and voltage by a robot controller according to claim 3, characterized in that: The operational amplifier module includes an operational amplifier U4A and an operational amplifier U4B. The input end of the operational amplifier U4A is connected to the output end of the signal conversion chip U2, and the input end of the operational amplifier U4B is connected to the output end of the signal conversion chip U6.

5. The circuit for setting welding machine current and voltage by robot controller according to claim 4, characterized in that: It also includes a capacitor C13, a capacitor C25, a transient voltage suppression diode D2, and a transient voltage suppression diode D3. The capacitor C13 and the transient voltage suppression diode D2 are connected in parallel to the output end of the operational amplifier U4A, and the capacitor C25 and the transient voltage suppression diode D3 are connected in parallel to the output end of the operational amplifier U4B.

6. The circuit for setting welding machine current and voltage by robot controller according to claim 1, characterized in that: Also includes: A power supply module, wherein the power supply module is connected to the signal conversion module and the operational amplifier module respectively, and the power supply module is used to convert voltage and provide power to the signal conversion module and the operational amplifier module.

7. A method for setting welding machine current and voltage by a robot controller, characterized in that: The method is applied to the circuit for setting welding machine current and voltage for a robot controller according to any one of claims 1 to 6, and the method comprises: Receive the voltage value input by the user; According to the received input voltage value, the corresponding PWM signal duty cycle is calculated and a PWM signal is generated; The generated PWM signal is isolated by an optical coupling isolation module and then transmitted to a signal conversion module, and the signal conversion module generates a corresponding analog voltage signal according to the received PWM signal; The analog voltage signal output by the signal conversion module is buffered, isolated and signal conditioned by the operational amplifier module to output a stable analog voltage signal.

8. The method for setting welding machine current and voltage by a robot controller according to claim 7, characterized in that: The method further comprises: The analog voltage signal output by the operational amplifier module is transmitted to the input end of the welding machine and is used as the current or voltage given signal of the welding machine; After receiving the current or voltage given signal, the welding machine sets the corresponding welding current or voltage and performs welding.

9. The method for setting welding machine current and voltage by a robot controller according to claim 8, characterized in that: The method further comprises: After the welding machine receives the current or voltage given signal, the current welding current or voltage is displayed on the welding machine LED panel.

10. The method for setting welding machine current and voltage by a robot controller according to claim 7, characterized in that: The frequency of the PWM signal is fixed at 1 KHz, and the duty cycle is linearly related to the input voltage. The input voltage range is 0V to 10V, and the duty cycle range is 0% to 100%.

Images