Electric spark machine tool operation and maintenance method based on digital twinning

Abstract

The invention relates to the technical field of machine tool operation and maintenance, and particularly discloses an electric discharge machine tool operation and maintenance method based on digital twinning, which comprises the following steps: acquiring discharge parameters of an electric discharge machine tool when parts in the same batch are processed to correspond to the same part, and analyzing discharge stability coefficients of the parts in the same batch processed by the electric discharge machine tool; identifying whether the electric discharge machine tool has an abnormal discharge behavior or not based on the result; if the abnormal discharge behavior of the EDM machine tool is identified, performing corresponding operation and maintenance adjustment on the EDM machine tool; meanwhile, through an equipped electrode abrasion monitoring sensor, the initial volume of each part of the electric spark machine tool during machining of the same batch is obtained in real time, the abrasion rate of the electrode is analyzed through an algorithm, and if the abrasion rate of the electrode is larger than a set abrasion threshold value, machining parameters of the electric spark machine tool are automatically adjusted; the operation and maintenance efficiency of the EDM machine tool can be remarkably improved, the production cost is reduced, and the product quality is ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of machine tool operation and maintenance, and relates to an electric spark machine tool operation and maintenance method based on digital twin. Background Art

[0002] EDM machine is a kind of processing equipment that uses electric spark discharge to corrode materials. It is widely used in mold manufacturing and complex parts processing. However, during the operation of traditional EDM machine tools, abnormal discharge state or severe electrode wear often leads to reduced processing quality or equipment damage. The emergence of these problems highlights the importance of EDM machine tool operation and maintenance management. However, the current operation and maintenance technology still has significant defects and disadvantages in many aspects: First, traditional EDM machines lack real-time monitoring capabilities. Most equipment relies on regular inspections to identify problems, which is not only inefficient but also prone to delayed discovery of problems, making it impossible to respond to risks caused by abnormal discharge or electrode wear in a timely manner. In addition, many machine tools lack intelligent sensors and data acquisition systems, making it impossible to obtain and analyze key discharge parameters in real time, resulting in the inability to dynamically adjust machining parameters to optimize the process. Secondly, the maintenance strategy of many machine tools is still based on preventive maintenance at fixed time intervals, rather than predictive maintenance based on equipment status. This approach cannot effectively prevent sudden failures and is prone to unexpected downtime and production interruptions. Summary of the invention

[0003] In view of the above problems existing in the prior art, the present invention provides an EDM machine tool operation and maintenance method based on digital twin, which is used to solve the above technical problems.

[0004] In order to achieve the above purpose and other purposes, the technical solution adopted by the present invention is as follows: A first aspect of the present invention provides an operation and maintenance method for an EDM machine tool based on digital twins, the method comprising the following steps: Based on the digital twin technology, a one-to-one model of the EDM machine tool is built to obtain the digital twin model of the EDM machine tool, and the physical machine tool is connected to the digital twin model through the Internet of Things technology; The digital twin model of the EDM machine tool collects the discharge parameters of the EDM machine tool when processing the same part of each part in the same batch, analyzes the discharge stability coefficient of the EDM machine tool when processing each part in the same batch, and identifies whether the EDM machine tool has abnormal discharge behavior based on it; if abnormal discharge behavior is identified, the EDM machine tool is adjusted accordingly for operation and maintenance; The parts in the same batch are numbered in sequence. The initial volume of the EDM machine electrode during processing of each part in the same batch is monitored in real time through the electrode wear monitoring sensor equipped on the physical machine tool and sent to the digital twin model. The electrode wear rate is analyzed through an algorithm. If the electrode wear rate is greater than the set wear threshold, the processing parameters of the EDM machine are automatically adjusted.

[0005] The analysis logic of the discharge stability coefficient of EDM machine tools in processing each part in the same batch is as follows: Based on the discharge parameters of the EDM machine when processing the same part of each part in the same batch, the voltage, current, pulse duration and pulse interval time of the EDM machine when processing the same part of each part in the same batch are extracted and marked in sequence. Instead, j is the number of each part in the same batch, j=1,2,...J, J represents the total number of parts in the same batch; The comprehensive index of discharge parameters of each part of the EDM machine tool is calculated from this , The specific calculation formula is shown as follows: ; In the above formula They respectively represent the mean voltage, mean current, mean pulse duration and mean pulse interval time of the EDM machine tool when processing the same part of the same batch of parts. They respectively represent the voltage standard deviation, current standard deviation, pulse duration standard deviation and pulse interval standard deviation of the EDM machine tool when processing the same part of the parts in the same batch; ω1, ω2, ω3, ω4 respectively represent the set voltage calculation weight, current calculation weight, pulse duration calculation weight and pulse interval calculation weight; The environmental parameters corresponding to each part in the same batch of EDM machine tools are collected synchronously. The environmental parameters are divided into temperature and humidity, which are recorded as ; Substitute the temperature and humidity corresponding to each part in the same batch processed by the EDM machine into the calculation formula of the environmental impact factor of each part in the same batch processed by the EDM machine to obtain the environmental impact factor of each part in the same batch processed by the EDM machine , where WD and SD represent the standard ambient temperature and standard ambient humidity respectively, α1, α2 and α3 represent the set temperature influence coefficient, humidity influence coefficient and temperature-humidity interaction influence coefficient respectively; Finally, based on the discharge parameter comprehensive index and environmental impact factor of each part of the EDM machine tool, the discharge stability coefficient of each part in the same batch of EDM machine tools is comprehensively analyzed. .

[0006] Identify whether the EDM machine tool has abnormal discharge behavior. The specific identification logic is: Based on the discharge stability coefficient of EDM machine tools in processing parts in the same batch Then, the discharge stability average value and discharge stability standard deviation of the EDM machine tool in processing the same batch of parts are calculated and recorded as ; The upper and lower thresholds of abnormality detection for EDM machines in processing parts in the same batch are set accordingly. The specific setting process is as follows: ; ; in and They represent the upper and lower thresholds of abnormality detection of the EDM machine tool when processing parts in the same batch, respectively; k is a set calculation constant, which sets the sensitivity for detection; Then identify the authenticity of the discharge anomaly of the EDM machine tool when processing each part in the same batch ; The total number of true discharge anomalies corresponding to the parts in the same batch processed by the EDM machine tool is counted, and it is used as the numerator in the fraction, and the total number of parts in the same batch is used as the denominator in the fraction. The fraction is solved to obtain the discharge anomaly ratio of the parts in the same batch processed by the EDM machine tool; The discharge abnormality ratio of the EDM machine tool when processing parts in the same batch is compared with the set allowable abnormality ratio. If the former is greater than the latter, it is determined that the EDM machine tool has abnormal discharge behavior, otherwise it is determined that the EDM machine tool does not have abnormal discharge behavior.

[0007] Make corresponding operation and maintenance adjustments to the EDM machine tool. The specific adjustment logic is as follows: Based on the voltage, current, pulse duration and pulse interval of the EDM machine tool when processing the same part of each part in the same batch, the Z-score method is used to determine the abnormal type of abnormal discharge behavior of the EDM machine tool, among which the abnormal type is specifically divided into voltage abnormality, current abnormality, pulse duration abnormality and pulse interval abnormality. If the abnormal discharge behavior of the EDM machine tool is identified as voltage abnormality, the voltage threshold range is determined according to the processing requirements of the same part of the part. , and the iterative adjustment formula for the corresponding voltage operation and maintenance adjustment of the EDM machine tool is calculated as follows: ; In the above formula, △DY is the voltage deviation value. , DY' is the voltage target value, is the set voltage adjustment step value, Iteratively adjust the voltage value for the EDM machine tool to perform corresponding voltage operation and maintenance adjustments; The iterative adjustment voltage value for the EDM machine tool to perform the corresponding voltage operation and maintenance adjustment is equal to If the difference between the iteratively adjusted voltage value of the EDM machine tool for corresponding voltage operation and maintenance adjustment and the voltage target value is not within the set difference allowable range, a second or even multiple iterations will be performed until the difference between the iteratively adjusted voltage value of the EDM machine tool for corresponding voltage operation and maintenance adjustment and the voltage target value is within the set difference allowable range; If the abnormal discharge behavior of the EDM machine tool is identified as current abnormality, pulse duration abnormality or pulse interval abnormality, the current operation, pulse duration operation or pulse interval operation of the EDM machine tool is adjusted accordingly according to the above-mentioned adjustment method of the corresponding voltage operation and maintenance of the EDM machine tool.

[0008] The Z-score method is used to determine the abnormal type of abnormal discharge behavior of the EDM machine tool. The specific determination process includes: Obtain the voltage of the EDM machine when processing the same part of each part in the same batch, and then use the Z-score method to calculate the mean Z-score of the voltage of the EDM machine when processing the parts in the same batch ; Then determine the authenticity of the corresponding voltage anomaly of the EDM machine tool , k1 is the set voltage Z-score calculation constant; If the calculation result of the authenticity of the corresponding voltage anomaly of the EDM machine tool is , then it is determined that the abnormal type of abnormal discharge behavior of the EDM machine tool is voltage abnormality; Based on the calculation method for determining the authenticity of the corresponding voltage anomaly of the EDM machine, the authenticity of the corresponding current anomaly, pulse duration anomaly and pulse interval anomaly of the EDM machine can be determined in the same way; If the authenticity of the EDM machine tool in the corresponding current anomaly is indicated as True, then the abnormal type of abnormal discharge behavior of the EDM machine tool is determined to be current anomaly; If the authenticity of the EDM machine tool in the corresponding pulse continuous abnormality is indicated as True, then the abnormal type of abnormal discharge behavior of the EDM machine tool is determined to be pulse continuous abnormality; If the authenticity of the EDM machine tool in the corresponding pulse interval abnormality is indicated as True, then the abnormal type of abnormal discharge behavior of the EDM machine tool is determined to be the pulse interval abnormality; Based on the above judgment process, the abnormal type of abnormal discharge behavior of the EDM machine tool can be comprehensively determined.

[0009] The wear rate of the electrode is analyzed by algorithms, including: The initial volume of the EDM machine tool electrode in processing each part in the same batch is recorded as , j is the number of each part in the same batch; The total time t spent by the EDM machine tool in processing the same batch of parts is simultaneously recorded, and the electrode wear rate is calculated from this. , J represents the total number of parts in the same batch, It represents the initial volume of the EDM machine electrode when processing the j-1th part in the same batch, and τ is the set error correction value.

[0010] The machining parameters of the electric spark machine tool are discharge gap, pulse width, working fluid pressure and electrode feed speed.

[0011] Automatically adjust the discharge gap and pulse width of the EDM machine. The specific adjustment process is as follows: Obtaining the electrode wear rate η; Calculate the adjustment value of the discharge gap of the EDM machine tool ; Calculate the adjustment value of the pulse width corresponding to the EDM machine tool ; In the above formula They are respectively the current value of the discharge gap and the current value of the pulse width of the EDM machine. Wear adjustment threshold set for the electrode, The maximum permissible threshold value of the wear rate set for the electrode, λ1 and λ2 represent the set adjustment coefficients, which are used to control the adjustment range.

[0012] Automatically adjust the working fluid pressure and electrode feed speed of the EDM machine. The specific adjustment process is: Calculate the adjustment value of the corresponding working hydraulic pressure of the EDM machine ; Calculate the adjustment value of the electrode feed speed corresponding to the EDM machine tool ; In the above formula They are the current value of the working hydraulic pressure and the current value of the electrode feed speed of the EDM machine tool respectively. λ3 and λ4 represent the set adjustment coefficients, which are used to control the adjustment range.

[0013] A second aspect of the present invention provides an EDM machine tool operation and maintenance device based on digital twins, comprising a processor, a memory, and a communication bus; The memory stores a computer-readable program executable by the processor; The communication bus realizes the connection and communication between the processor and the memory; When the processor executes the computer-readable program, the steps in the above-mentioned electric discharge machine tool operation and maintenance method based on digital twin are implemented.

[0014] The third aspect of the present invention provides a computer-readable storage medium, which stores one or more programs. The one or more programs can be executed by one or more processors to implement the steps in the above-mentioned digital twin-based EDM machine operation and maintenance method.

[0015] As described above, the EDM machine tool operation and maintenance method based on digital twin provided by the present invention has at least the following beneficial effects: (1) The embodiment of the present invention can effectively evaluate the discharge stability of the EDM machine tool by monitoring and analyzing the discharge parameters of each part in the same batch of parts, and then identify whether there is abnormal discharge behavior. The necessity of this process lies in that abnormal discharge will not only lead to a decrease in processing accuracy, but also may cause equipment damage, increase production costs and downtime. Therefore, timely identification and adjustment of abnormal discharge behavior is an important link to ensure the normal operation of the equipment. The analysis of the discharge stability coefficient can provide information about the consistency and reliability of the discharge of the EDM machine tool during the processing process. By comparing the discharge parameters of parts in the same batch, potential abnormal fluctuations can be found. Such fluctuations may be caused by uneven electrode wear, unstable working fluid pressure or equipment failure. After identifying these anomalies, the EDM machine tool can be immediately adjusted for operation and maintenance to restore the stability and accuracy of the processing.

[0016] (2) The embodiment of the present invention is equipped with an electrode wear monitoring sensor to obtain the initial volume of the electrode and calculate the wear rate in real time, making the management of the electrode more scientific and efficient. When the wear rate of the electrode is detected to exceed the set threshold, the system can automatically adjust the processing parameters, such as reducing the discharge current, optimizing the pulse width or increasing the discharge gap, to extend the service life of the electrode. This adaptive adjustment not only improves the utilization rate of the electrode, but also reduces the processing defects and downtime caused by electrode wear.

[0017] (3) The embodiments of the present invention can significantly improve the operation and maintenance efficiency of EDM machines, reduce production costs, and ensure product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0019] Figure 1 It is a schematic diagram of the connection of each step of the method of the present invention. DETAILED DESCRIPTION

[0020] The above contents in combination with the implementation of the present invention are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the described specific embodiments or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

[0021] Example 1 See also Figure 1 As shown, an EDM machine tool operation and maintenance method based on digital twins includes the following steps: Based on the digital twin technology, a one-to-one model of the EDM machine tool is built to obtain the digital twin model of the EDM machine tool, and the physical machine tool is connected to the digital twin model through the Internet of Things technology; The digital twin model of the EDM machine tool collects the discharge parameters of the EDM machine tool when processing the same part of each part in the same batch, analyzes the discharge stability coefficient of the EDM machine tool when processing each part in the same batch, and identifies whether the EDM machine tool has abnormal discharge behavior based on it; if abnormal discharge behavior is identified, the EDM machine tool is adjusted accordingly for operation and maintenance; In the preferred technical solution of this application, the analysis logic of the discharge stability coefficient of the EDM machine tool is as follows: Based on the discharge parameters of the EDM machine when processing the same part of each part in the same batch, the voltage, current, pulse duration and pulse interval time of the EDM machine when processing the same part of each part in the same batch are extracted and marked in sequence. Instead, j is the number of each part in the same batch, j=1,2,...J, J represents the total number of parts in the same batch; The comprehensive index of discharge parameters of each part of the EDM machine tool is calculated from this , The specific calculation formula is shown as follows: ; In the above formula They respectively represent the mean voltage, mean current, mean pulse duration and mean pulse interval time of the EDM machine tool when processing the same part of the same batch of parts. They respectively represent the voltage standard deviation, current standard deviation, pulse duration standard deviation and pulse interval standard deviation of the EDM machine tool when processing the same part of the parts in the same batch; ω1, ω2, ω3, ω4 respectively represent the set voltage calculation weight, current calculation weight, pulse duration calculation weight and pulse interval calculation weight, and ω1+ω2+ω3+ω4=1 must be satisfied; Indicates the actual current size during the discharge process, in amperes (A); in EDM, the current size directly affects the processing efficiency and surface roughness. Larger currents usually increase processing speeds, but may result in reduced surface quality. Indicates the degree of current fluctuation during the entire processing. If the standard deviation is large, it means that the current fluctuation is large and the processing is unstable; Usually measured in volts (V), the voltage affects the formation of the discharge gap and the transfer of discharge energy. A stable voltage helps uniform processing, but if the voltage fluctuates greatly, it may lead to unstable discharge. Indicates the degree of voltage fluctuation; Indicates the duration of each discharge, usually in microseconds. The longer the pulse duration, the greater the discharge energy per unit time, which helps to improve the material removal rate, but may lead to an increase in the heat affected area; Indicates the time interval between two discharges, usually in microseconds. The shorter the pulse interval, the faster the processing speed, but it may cause unstable processing (such as discharge short circuit or over-discharge).

[0022] The environmental parameters corresponding to each part in the same batch of EDM machine tools are collected synchronously. The environmental parameters are divided into temperature and humidity, which are recorded as ; Substitute the temperature and humidity corresponding to each part in the same batch processed by the EDM machine into the calculation formula of the environmental impact factor of each part in the same batch processed by the EDM machine to obtain the environmental impact factor of each part in the same batch processed by the EDM machine , where WD and SD represent the standard ambient temperature and standard ambient humidity respectively, α1, α2 and α3 represent the set temperature influence coefficient, humidity influence coefficient and temperature-humidity interaction influence coefficient respectively; The temperature influence coefficient α1 indicates the degree of influence of temperature on the discharge process; temperature changes will affect the dielectric properties of the discharge gap, thereby affecting the stability of the discharge; higher temperatures may lead to increased evaporation of the dielectric, affecting the discharge efficiency and processing accuracy; The humidity influence coefficient α2 indicates the influence of humidity on the discharge process. Humidity changes will affect the conductivity of air and medium, thus affecting the discharge characteristics of the discharge gap. Higher humidity may lead to an increase in moisture in the medium, affecting the stability of the discharge process. The temperature-humidity interaction coefficient α3 indicates the degree of influence of the combined effects of temperature and humidity on the discharge process; the interaction between temperature and humidity may amplify or weaken the influence of a single factor. For example, in a high temperature and high humidity environment, the physical properties of the medium may change significantly, affecting the discharge stability.

[0023] Finally, based on the discharge parameter comprehensive index and environmental impact factor of each part of the EDM machine tool, the discharge stability coefficient of each part in the same batch of EDM machine tools is comprehensively analyzed. .

[0024] In the preferred technical solution of the present application, it is identified whether the EDM machine tool has abnormal discharge behavior, and the specific identification logic is: Based on the discharge stability coefficient of EDM machine tools in processing parts in the same batch Then, the discharge stability average value and discharge stability standard deviation of the EDM machine tool in processing the same batch of parts are calculated and recorded as ; The upper and lower thresholds of abnormality detection for EDM machines in processing parts in the same batch are set accordingly. The specific setting process is as follows: ; ; in and They represent the upper and lower thresholds of abnormality detection for EDM machines in processing parts in the same batch, respectively. k is a set calculation constant, which sets the sensitivity for detection. The value of k is usually 2 or 3. The specific meanings are as follows: When k=2, it means that the detection range is two times the standard deviation of the mean value, which is suitable for situations where more anomalies are expected to be detected; when k=3, it means that the detection range is three times the standard deviation of the mean value, which is suitable for situations where only obvious anomalies are expected to be detected. By adjusting the value of k, the sensitivity and false alarm rate of anomaly detection can be controlled. Then identify the authenticity of the discharge anomaly of the EDM machine tool when processing each part in the same batch ; The total number of true discharge anomalies corresponding to the parts in the same batch processed by the EDM machine tool is counted, and it is used as the numerator in the fraction, and the total number of parts in the same batch is used as the denominator in the fraction. The fraction is solved to obtain the discharge anomaly ratio of the parts in the same batch processed by the EDM machine tool; The discharge abnormality ratio of the EDM machine tool when processing parts in the same batch is compared with the set allowable abnormality ratio. If the former is greater than the latter, it is determined that the EDM machine tool has abnormal discharge behavior, otherwise it is determined that the EDM machine tool does not have abnormal discharge behavior; the former refers to the discharge abnormality ratio of the EDM machine tool when processing parts in the same batch, and the latter refers to the set allowable abnormality ratio.

[0025] In the preferred technical solution of this application, the EDM machine tool is adjusted for operation and maintenance accordingly, and the specific adjustment logic is: Based on the voltage, current, pulse duration and pulse interval of the EDM machine tool when processing the same part of each part in the same batch, the Z-score method is used to determine the abnormal type of abnormal discharge behavior of the EDM machine tool, among which the abnormal type is specifically divided into voltage abnormality, current abnormality, pulse duration abnormality and pulse interval abnormality. If the abnormal discharge behavior of the EDM machine tool is identified as voltage abnormality, the voltage threshold range is determined according to the processing requirements of the same part of the part. , and the iterative adjustment formula for the corresponding voltage operation and maintenance adjustment of the EDM machine tool is calculated as follows: ; In the above formula, △DY is the voltage deviation value. , DY' is the voltage target value, is the set voltage adjustment step value, Iteratively adjust the voltage value for the EDM machine tool to perform corresponding voltage operation and maintenance adjustments; The specific steps for determining the voltage threshold range and setting the adjustment voltage step value are as follows: First, according to the processing requirements and material properties, a detailed process analysis is required, including research on the electrical conductivity, thermal conductivity and response characteristics of the processed material to EDM. Combined with the technical parameters of the equipment and the recommended operating manual, a voltage threshold range suitable for the process is formulated. Usually, preliminary data can be obtained through experiments and multiple processing verifications can be performed to optimize the range; secondly, when setting the adjustment voltage step value, the sensitivity and processing accuracy of the equipment should be considered, and a suitable step should be selected. It is generally recommended to start with a smaller step, such as 1-5V, and gradually adjust the step according to the response speed of the equipment to voltage changes and the feedback of processing quality to ensure that no excessive fluctuations are caused during the adjustment process, and that precise control can be achieved, thereby ensuring the stability of the processing process and product quality; The iterative adjustment voltage value for the EDM machine tool to perform the corresponding voltage operation and maintenance adjustment is equal to If the difference between the iteratively adjusted voltage value of the EDM machine tool for corresponding voltage operation and maintenance adjustment and the voltage target value is not within the set difference allowable range, a second or even multiple iterations will be performed until the difference between the iteratively adjusted voltage value of the EDM machine tool for corresponding voltage operation and maintenance adjustment and the voltage target value is within the set difference allowable range; If the abnormal discharge behavior of the EDM machine tool is identified as current abnormality, pulse duration abnormality or pulse interval abnormality, the current operation, pulse duration operation or pulse interval operation of the EDM machine tool is adjusted accordingly according to the above-mentioned adjustment method of the corresponding voltage operation and maintenance of the EDM machine tool.

[0026] In the preferred technical solution of the present application, the Z-score method is used to determine the abnormal type of abnormal discharge behavior of the EDM machine tool, and the specific determination process includes: Obtain the voltage of the EDM machine when processing the same part of each part in the same batch, and then use the Z-score method to calculate the mean Z-score of the voltage of the EDM machine when processing the parts in the same batch ; Then determine the authenticity of the corresponding voltage anomaly of the EDM machine tool , k1 is the set voltage Z-score calculation constant; If the calculation result of the authenticity of the corresponding voltage anomaly of the EDM machine tool is , then it is determined that the abnormal type of abnormal discharge behavior of the EDM machine tool is voltage abnormality; Based on the calculation method for determining the authenticity of the corresponding voltage anomaly of the EDM machine, the authenticity of the corresponding current anomaly, pulse duration anomaly and pulse interval anomaly of the EDM machine can be determined in the same way; If the authenticity of the EDM machine tool in the corresponding current anomaly is indicated as True, then the abnormal type of abnormal discharge behavior of the EDM machine tool is determined to be current anomaly; If the authenticity of the EDM machine tool in the corresponding pulse continuous abnormality is indicated as True, then the abnormal type of abnormal discharge behavior of the EDM machine tool is determined to be pulse continuous abnormality; If the authenticity of the EDM machine tool in the corresponding pulse interval abnormality is indicated as True, then the abnormal type of abnormal discharge behavior of the EDM machine tool is determined to be the pulse interval abnormality; Based on the above judgment process, the abnormal type of abnormal discharge behavior of the EDM machine tool can be comprehensively determined.

[0027] The parts in the same batch are numbered in sequence. The initial volume of the EDM machine electrode during processing of each part in the same batch is monitored in real time through the electrode wear monitoring sensor equipped on the physical machine tool and sent to the digital twin model. The electrode wear rate is analyzed through an algorithm. If the electrode wear rate is greater than the set wear threshold, the processing parameters of the EDM machine are automatically adjusted.

[0028] In a preferred technical solution of the present application, the wear rate of the electrode is analyzed by an algorithm, including: The initial volume of the EDM machine tool electrode in processing each part in the same batch is recorded as , j is the number of each part in the same batch; The total time t spent by the EDM machine tool in processing the same batch of parts is simultaneously recorded, and the electrode wear rate is calculated from this. , J represents the total number of parts in the same batch, It represents the initial volume of the EDM machine electrode when processing the j-1th part in the same batch, and τ is the set error correction value.

[0029] In a preferred technical solution of the present application, the machining parameters of the electric spark machine tool are discharge gap, pulse width, working fluid pressure and electrode feed speed.

[0030] When the electrode wear rate exceeds the set wear threshold, the EDM machine tool processing parameters (including discharge gap, pulse width, working fluid pressure and electrode feed speed) are adjusted to optimize the processing process, extend the electrode life and ensure the processing quality. The selection of these four parameters is based on their direct impact on the discharge process and electrode wear: First, the discharge gap is the distance between the electrode and the workpiece during the discharge process. An appropriate discharge gap can ensure stable discharge conditions and reduce excessive wear of the electrode. When the wear rate is too high, increasing the discharge gap can reduce the contact frequency between the electrode and the workpiece, thereby reducing wear; Secondly, the pulse width determines the duration of each discharge. Adjusting the pulse width can affect the discharge energy, which in turn affects the material removal rate and the degree of electrode wear. Shortening the pulse width can reduce the discharge energy and reduce electrode wear; The working fluid pressure has an important influence on the chip removal and cooling effect in the discharge gap. Properly increasing the working fluid pressure can more effectively remove the debris generated by the discharge, prevent the electrode from being worn due to secondary discharge, and improve the cooling effect and reduce the thermal wear of the electrode. Finally, the electrode feed speed controls the feed rate of the electrode to the workpiece. Proper adjustment of the feed speed can ensure that the electrode works within the appropriate discharge gap and avoid excessive contact between the electrode and the workpiece caused by excessive feeding, thereby increasing wear; In summary, these four parameters directly affect the discharge conditions, energy transfer and thermal management of EDM. By adjusting these parameters, the machining environment can be optimized when the wear rate is too high, electrode wear can be reduced, and machining quality and efficiency can be improved. This adjustment strategy can not only extend the service life of the electrode, but also ensure the stability and controllability of the machining process.

[0031] In the preferred technical solution of the present application, the discharge gap and pulse width of the EDM machine tool are automatically adjusted, and the specific adjustment process is: Obtaining the electrode wear rate η; Calculate the adjustment value of the discharge gap of the EDM machine tool , using the logarithmic function log can achieve smooth adjustment and avoid drastic changes; Calculate the adjustment value of the pulse width corresponding to the EDM machine tool , using an exponential function to quickly respond to large wear differences; In the above formula They are respectively the current value of the discharge gap and the current value of the pulse width of the EDM machine. Wear adjustment threshold set for the electrode, The maximum permissible threshold value of the wear rate set for the electrode, λ1 and λ2 represent the set adjustment coefficients, which are used to control the adjustment range.

[0032] In the preferred technical solution of the present application, the working fluid pressure and electrode feed speed of the EDM machine tool are automatically adjusted, and the specific adjustment process is: Calculate the adjustment value of the corresponding working hydraulic pressure of the EDM machine , using the sine function sin, provides nonlinear adjustment; Calculate the adjustment value of the electrode feed speed corresponding to the EDM machine tool , using the hyperbolic tangent function, limiting extreme adjustments; In the above formula are the current values ​​of the working hydraulic pressure and the electrode feed speed of the EDM machine tool, respectively. λ3 and λ4 represent the set adjustment coefficients, which are used to control the adjustment amplitude. tanh(·) represents the hyperbolic tangent function.

[0033] In the above formula, λ1, λ2, λ3 and λ4 usually take values ​​between 0 and 1; The wear adjustment threshold of the electrode setting in the above calculation formula and the maximum permissible threshold of the wear rate of the electrode setting The specific meanings are as follows: Wear adjustment threshold for electrode settings This is a target value used to determine when the machining parameters need to be adjusted. If the electrode wear rate exceeds this value, it means that adjustments need to be made to optimize the machining process. Maximum permissible threshold value for electrode wear rate setting This is a limit value, indicating the maximum acceptable range of electrode wear rate. Exceeding this value may lead to reduced processing quality or equipment damage. It is used in the formula to normalize and calculate the adjustment range to ensure that the adjustment is carried out within a safe range. In summary, is a trigger point, and It’s a safety boundary.

[0034] Example 2 An EDM machine tool operation and maintenance device based on digital twins, comprising a processor, a memory and a communication bus; The memory stores a computer-readable program executable by the processor; The communication bus realizes the connection and communication between the processor and the memory; When the processor executes the computer-readable program, the steps in the above-mentioned electric discharge machine tool operation and maintenance method based on digital twin are implemented.

[0035] Example 3 A computer-readable storage medium stores one or more programs, and the one or more programs can be executed by one or more processors to implement the steps in the above-mentioned digital twin-based EDM machine tool operation and maintenance method.

[0036] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0037] It should be understood that determining B based on A does not mean determining B only based on A. B can also be determined based on A and / or other information.

[0038] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0039] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An EDM machine tool operation and maintenance method based on digital twin, characterized in that: The steps include: Based on the digital twin technology, a one-to-one model of the EDM machine tool is built to obtain the digital twin model of the EDM machine tool, and the physical machine tool is connected to the digital twin model through the Internet of Things technology; The digital twin model of the EDM machine tool collects the discharge parameters of the EDM machine tool when processing the same part of each part in the same batch, analyzes the discharge stability coefficient of the EDM machine tool when processing each part in the same batch, and based on it, identifies whether the EDM machine tool has abnormal discharge behavior; If abnormal discharge behavior is detected in the EDM machine, corresponding operation and maintenance adjustments will be made to the EDM machine; The parts in the same batch are numbered in sequence. The initial volume of the EDM machine electrode during processing of each part in the same batch is monitored in real time through the electrode wear monitoring sensor equipped on the physical machine tool and sent to the digital twin model. The electrode wear rate is analyzed through an algorithm. If the electrode wear rate is greater than the set wear threshold, the processing parameters of the EDM machine are automatically adjusted.

2. The operation and maintenance method of an EDM machine tool based on digital twin according to claim 1 is characterized in that: The analysis logic of the discharge stability coefficient of EDM machine tools in processing each part in the same batch is as follows: Based on the discharge parameters of the EDM machine when processing the same part of each part in the same batch, the voltage, current, pulse duration and pulse interval time of the EDM machine when processing the same part of each part in the same batch are extracted and marked in sequence. Instead, j is the number of each part in the same batch, j=1,2,...J, J represents the total number of parts in the same batch; The comprehensive index of discharge parameters of each part of the EDM machine tool is calculated from this , The specific calculation formula is shown as follows: ； In the above formula They respectively represent the mean voltage, mean current, mean pulse duration and mean pulse interval of the EDM machine tool when processing the same part of the same batch of parts. They respectively represent the voltage standard deviation, current standard deviation, pulse duration standard deviation and pulse interval standard deviation of the EDM machine tool when processing the same part of the parts in the same batch; ω1, ω2, ω3 and ω4 respectively represent the set voltage calculation weight, current calculation weight, pulse duration calculation weight and pulse interval calculation weight; The environmental parameters corresponding to each part in the same batch of EDM machine tools are collected synchronously. The environmental parameters are divided into temperature and humidity, which are recorded as ; Substitute the temperature and humidity corresponding to each part in the same batch processed by the EDM machine into the calculation formula of the environmental impact factor of each part in the same batch processed by the EDM machine to obtain the environmental impact factor of each part in the same batch processed by the EDM machine , where WD and SD represent the standard ambient temperature and standard ambient humidity respectively, α1, α2 and α3 represent the set temperature influence coefficient, humidity influence coefficient and temperature-humidity interaction influence coefficient respectively; Finally, based on the discharge parameter comprehensive index and environmental impact factor of each part of the EDM machine tool, the discharge stability coefficient of each part in the same batch of EDM machine tools is comprehensively analyzed. .

3. The method for operating and maintaining an EDM machine tool based on digital twin according to claim 2, characterized in that: Identify whether the EDM machine tool has abnormal discharge behavior. The specific identification logic is: Based on the discharge stability coefficient of EDM machine tools in processing parts in the same batch Then, the discharge stability average value and discharge stability standard deviation of the EDM machine tool in processing the same batch of parts are calculated and recorded as ; The upper and lower thresholds of abnormality detection for EDM machines in processing parts in the same batch are set accordingly. The specific setting process is as follows: ； ； in and They represent the upper and lower thresholds of abnormality detection of the EDM machine tool when processing parts in the same batch, respectively; k is a set calculation constant, which sets the sensitivity used for detection; Then identify the authenticity of the discharge anomaly of the EDM machine tool when processing each part in the same batch ； The total number of true discharge anomalies corresponding to the parts in the same batch processed by the EDM machine tool is counted, and it is used as the numerator in the fraction, and the total number of parts in the same batch is used as the denominator in the fraction. The fraction is solved to obtain the discharge anomaly ratio of the parts in the same batch processed by the EDM machine tool; The discharge abnormality ratio of the EDM machine tool when processing parts in the same batch is compared with the set allowable abnormality ratio. If the former is greater than the latter, it is determined that the EDM machine tool has abnormal discharge behavior, otherwise it is determined that the EDM machine tool does not have abnormal discharge behavior.

4. The operation and maintenance method of an EDM machine tool based on digital twin according to claim 3 is characterized in that: Make corresponding operation and maintenance adjustments to the EDM machine tool. The specific adjustment logic is as follows: Based on the voltage, current, pulse duration and pulse interval of the EDM machine tool when processing the same part of each part in the same batch, the Z-score method is used to determine the abnormal type of abnormal discharge behavior of the EDM machine tool, among which the abnormal type is specifically divided into voltage abnormality, current abnormality, pulse duration abnormality and pulse interval abnormality. If the abnormal discharge behavior of the EDM machine tool is identified as voltage abnormality, the voltage threshold range is determined according to the processing requirements of the same part of the part. , and the iterative adjustment formula for the corresponding voltage operation and maintenance adjustment of the EDM machine tool is calculated as follows: ; In the above formula, △DY is the voltage deviation value. , DY' is the voltage target value, is the set voltage adjustment step value, Iteratively adjust the voltage value for the EDM machine tool to perform corresponding voltage operation and maintenance adjustments; The iterative adjustment voltage value for the EDM machine tool to perform the corresponding voltage operation and maintenance adjustment is equal to If the difference between the iteratively adjusted voltage value of the EDM machine tool for corresponding voltage operation and maintenance adjustment and the voltage target value is not within the set difference allowable range, a second or even multiple iterations will be performed until the difference between the iteratively adjusted voltage value of the EDM machine tool for corresponding voltage operation and maintenance adjustment and the voltage target value is within the set difference allowable range; If the abnormal discharge behavior of the EDM machine tool is identified as current abnormality, pulse duration abnormality or pulse interval abnormality, the current operation, pulse duration operation or pulse interval operation of the EDM machine tool is adjusted accordingly according to the above-mentioned adjustment method of the corresponding voltage operation and maintenance of the EDM machine tool.

5. The method for operating and maintaining an EDM machine tool based on digital twin according to claim 4 is characterized in that: The Z-score method is used to determine the abnormal type of abnormal discharge behavior in the EDM machine tool. The specific determination process includes: Obtain the voltage of the EDM machine when processing the same part of each part in the same batch, and then use the Z-score method to calculate the mean Z-score of the voltage of the EDM machine when processing the parts in the same batch ; Then determine the authenticity of the corresponding voltage anomaly of the EDM machine tool , k1 is the set voltage Z-score calculation constant; If the calculation result of the authenticity of the corresponding voltage anomaly of the EDM machine tool is , then it is determined that the abnormal type of abnormal discharge behavior of the EDM machine tool is voltage abnormality; Based on the calculation method for determining the authenticity of the corresponding voltage anomaly of the EDM machine, the authenticity of the corresponding current anomaly, pulse duration anomaly and pulse interval anomaly of the EDM machine can be determined in the same way; If the authenticity of the EDM machine tool in the corresponding current anomaly is indicated as True, then the abnormal type of abnormal discharge behavior of the EDM machine tool is determined to be current anomaly; If the authenticity of the EDM machine tool in the corresponding pulse continuous abnormality is indicated as True, then the abnormal type of abnormal discharge behavior of the EDM machine tool is determined to be pulse continuous abnormality; If the authenticity of the EDM machine tool in the corresponding pulse interval abnormality is indicated as True, then the abnormal type of abnormal discharge behavior of the EDM machine tool is determined to be the pulse interval abnormality; Based on the above judgment process, the abnormal type of abnormal discharge behavior of the EDM machine tool can be comprehensively determined.

6. The operation and maintenance method of an EDM machine tool based on digital twin according to claim 1 is characterized in that: The wear rate of the electrode is analyzed by algorithms, including: The initial volume of the EDM machine electrode in processing each part in the same batch is recorded as , j is the number of each part in the same batch; The total time t spent by the EDM machine tool in processing the same batch of parts is simultaneously recorded, and the electrode wear rate is calculated from this. , J represents the total number of parts in the same batch, It represents the initial volume of the EDM machine electrode when processing the j-1th part in the same batch, and τ is the set error correction value.

7. The method for operating and maintaining an EDM machine tool based on digital twin according to claim 1, characterized in that: The machining parameters of the electric spark machine tool are discharge gap, pulse width, working fluid pressure and electrode feed speed.

8. The method for operating and maintaining an EDM machine tool based on digital twin according to claim 7, characterized in that: Automatically adjust the discharge gap and pulse width of the EDM machine. The specific adjustment process is as follows: Obtaining the electrode wear rate η; Calculate the adjustment value of the discharge gap of the EDM machine tool ； Calculate the adjustment value of the pulse width corresponding to the EDM machine tool ； In the above formula They are respectively the current value of the discharge gap and the current value of the pulse width of the EDM machine. Wear adjustment threshold set for the electrode, The maximum permissible threshold value of the wear rate set for the electrode, λ1 and λ2 represent the set adjustment coefficients, which are used to control the adjustment range.

9. The method for operating and maintaining an EDM machine tool based on digital twin according to claim 8, characterized in that: Automatically adjust the working fluid pressure and electrode feed speed of the EDM machine. The specific adjustment process is: Calculate the adjustment value of the corresponding working hydraulic pressure of the EDM machine ； Calculate the adjustment value of the electrode feed speed corresponding to the EDM machine tool ； In the above formula They are the current value of the working hydraulic pressure and the current value of the electrode feed speed of the EDM machine tool respectively. λ3 and λ4 represent the set adjustment coefficients, which are used to control the adjustment range.

10. An EDM machine tool operation and maintenance device based on digital twin, characterized by: It is implemented based on an EDM machine tool operation and maintenance method based on digital twin as described in any one of claims 1 to 9, comprising a processor, a memory and a communication bus; The memory stores a computer-readable program executable by the processor; The communication bus realizes the connection and communication between the processor and the memory; When the processor executes the computer-readable program, it implements an EDM machine tool operation and maintenance method based on digital twin as described in any one of claims 1 to 9.

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