Tool state monitoring method and device based on ultrasonic machining frequency offset

Abstract

The application relates to the tool monitoring technical field, in particular to a tool state monitoring method and device based on an ultrasonic machining frequency offset, wherein the method comprises the following steps: recognizing an actual state of an ultrasonic machining system; in response to the actual state being an empty load resonance state and an amplitude stable state, controlling the ultrasonic machining system to perform system frequency tracking, so as to obtain a resonance frequency offset of the ultrasonic machining system; inputting the resonance frequency offset into a tool state monitoring model constructed in advance, so as to output a current wear amount of the tool, and generating a current state of the tool according to the current wear amount. Therefore, the problem that the monitoring signal stability and reliability are insufficient due to the complex sensor installation, the signal being easily disturbed by environmental noise and working condition changes and the low system integration, so that the accurate and real-time monitoring of the tool wear state is difficult to realize is solved.

Description

Technical Field

[0001] This application relates to the field of tool monitoring technology, and in particular to a tool condition monitoring method and device based on ultrasonic machining frequency offset. Background Technology

[0002] In related technologies, tool condition monitoring technology mostly relies on signals such as cutting force, vibration or acoustic emission. It obtains machining process information by placing external sensors near the machine tool or tool, and combines threshold judgment or model analysis to identify the tool wear condition.

[0003] However, in related technologies, the sensor installation is complicated, the signal is easily affected by environmental noise and changes in working conditions, and the system integration is low, which can easily lead to insufficient stability and reliability of the monitoring signal, making it difficult to achieve accurate and real-time monitoring of tool wear status, which urgently needs to be solved. Summary of the Invention

[0004] This application provides a tool condition monitoring method and device based on ultrasonic machining frequency offset, to solve the problem in related technologies that the complex sensor installation, the susceptibility of the signal to environmental noise and changes in working conditions, and the low system integration can easily lead to insufficient stability and reliability of the monitoring signal, making it difficult to achieve accurate and real-time monitoring of tool wear status.

[0005] The first aspect of this application provides a tool condition monitoring method based on ultrasonic machining frequency offset, comprising the following steps: identifying the actual state of the ultrasonic machining system; responding to the actual state being an unloaded resonant state and an amplitude stable state, controlling the ultrasonic machining system to perform system frequency tracking to obtain the resonant frequency offset of the ultrasonic machining system; inputting the resonant frequency offset into a pre-constructed tool condition monitoring model to output the current wear amount of the tool, and generating the current state of the tool based on the current wear amount.

[0006] Through the above technical means, the embodiments of this application can obtain the current state of the tool based on the resonant frequency offset, which can quantitatively reflect the degree of tool wear and its changing trend, thereby realizing real-time assessment and prediction of the tool's health status. Furthermore, the machining parameters can be adaptively adjusted or a tool replacement strategy can be triggered based on the current state of the tool, thereby avoiding problems such as decreased machining quality, tool breakage, or workpiece scrap caused by excessive tool wear, and improving the safety, stability, and machining efficiency of the ultrasonic machining process.

[0007] Optionally, in one embodiment of this application, before inputting the resonant frequency offset into the pre-built tool condition monitoring model, the method further includes: obtaining the training resonant frequency offset and training wear amount of the ultrasonic machining process; generating a model training set based on the training resonant frequency offset and the training wear amount; and training the model using the model training set based on the relationship between the cutting force and the resonant frequency after the resonant state, until the preset training conditions are met, thereby constructing the tool condition monitoring model.

[0008] Through the above technical means, the embodiments of this application can construct a tool condition monitoring model based on the relationship between cutting force and resonant frequency after the resonant state. The load change caused by cutting force can be mapped to the offset characteristics of the resonant frequency of the ultrasonic vibration system. It can realize online, real-time and continuous monitoring of the current state of the tool without introducing an additional force sensor, providing a reliable basis for state perception, life prediction and intelligent control of the machining process.

[0009] Optionally, in one embodiment of this application, the expression for the relationship between the cutting force and the resonant frequency is: , in, , , , , These represent the average external load (N), the transient theory, the actual ultrasonic amplitude under load, the resonant frequency offset, and the unloaded resonant frequency, respectively.

[0010] Through the above technical means, the embodiments of this application can quantify the relationship between cutting force and resonant frequency, and can transform the change of mechanical load acting on the tool during the cutting process into a measurable offset of the resonant frequency of the ultrasonic vibration system, thereby establishing a mathematical mapping relationship between cutting force and resonant frequency. This can further realize the indirect perception and estimation of cutting force changes, and provide basic support for the identification of tool wear state, the stability analysis of the machining process, and the construction of tool condition monitoring models.

[0011] Optionally, in one embodiment of this application, the expression for the tool condition monitoring model is: VB = G(Fchange) Wherein, VB represents the tool wear amount, Fchange represents the resonant frequency offset, and G() represents the tool condition monitoring model.

[0012] Through the above technical means, the embodiments of this application can utilize a tool condition monitoring model to directly output the tool wear amount from the input characteristic parameters such as the resonant frequency offset, thereby achieving rapid and real-time quantitative assessment of the tool wear state.

[0013] A second aspect of this application provides a tool condition monitoring device based on ultrasonic machining frequency offset, comprising: an identification module for identifying the actual state of an ultrasonic machining system; a control module for controlling the ultrasonic machining system to perform system frequency tracking in response to the actual state being an unloaded resonant state and an amplitude stable state, so as to obtain the resonant frequency offset of the ultrasonic machining system; and a monitoring module for inputting the resonant frequency offset into a pre-constructed tool condition monitoring model to output the current wear amount of the tool and generate the current state of the tool based on the current wear amount.

[0014] Optionally, in one embodiment of this application, it further includes: an acquisition module for acquiring the training resonant frequency offset and training wear amount during the ultrasonic machining process; a generation module for generating a model training set based on the training resonant frequency offset and the training wear amount; and a construction module for training the model using the model training set based on the relationship between the cutting force and the resonant frequency after the resonant state, until a preset training condition is reached, thereby constructing the tool condition monitoring model.

[0015] Optionally, in one embodiment of this application, the expression for the relationship between the cutting force and the resonant frequency is: , in, , , , , These represent the average external load (N), the transient theory, the actual ultrasonic amplitude under load, the resonant frequency offset, and the unloaded resonant frequency, respectively.

[0016] Optionally, in one embodiment of this application, the expression for the tool condition monitoring model is: VB = G(Fchange) Wherein, VB represents the tool wear amount, Fchange represents the resonant frequency offset, and G() represents the tool condition monitoring model.

[0017] A third aspect of this application provides an electronic device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the tool condition monitoring method based on ultrasonic machining frequency offset as described in the above embodiments.

[0018] A fourth aspect of this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described tool condition monitoring method based on ultrasonic machining frequency offset.

[0019] A fifth aspect of this application provides a computer program product, including a computer program that, when executed, is used to implement the above-described tool condition monitoring method based on ultrasonic machining frequency offset.

[0020] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0021] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a schematic diagram of a tool condition monitoring system based on ultrasonic machining frequency offset according to an embodiment of this application; Figure 2 This is a flowchart of a tool condition monitoring method based on ultrasonic machining frequency offset provided in an embodiment of this application; Figure 3 This is a flowchart of a tool condition monitoring method based on ultrasonic machining frequency offset according to an embodiment of this application; Figure 4 This is a block diagram of a tool condition monitoring device based on ultrasonic machining frequency offset according to an embodiment of this application; Figure 5 This is a schematic diagram of the structure of an electronic device according to an embodiment of this application.

[0022] Figure label: 10-Tool condition monitoring device based on ultrasonic machining frequency offset; 100-Identification module, 200-Control module, 300-Monitoring module; 501-Memory, 502-Processor, 503-Communication interface. Detailed Implementation

[0023] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0024] The following describes a tool condition monitoring method and apparatus based on ultrasonic machining frequency offset according to embodiments of this application, with reference to the accompanying drawings. Addressing the technical problems mentioned in the background art, such as complex sensor installation, susceptibility to environmental noise and changes in operating conditions, and low system integration leading to insufficient stability and reliability of monitoring signals, making accurate and real-time monitoring of tool wear status difficult, this application provides a tool condition monitoring method based on ultrasonic machining frequency offset. In this method, when the actual state of the ultrasonic machining system is identified as an unloaded resonant state and an amplitude stable state, the ultrasonic machining system is controlled to perform system frequency tracking to obtain the resonant frequency offset, which is then input into the tool condition monitoring model to output the current state of the tool. This method can characterize the tool wear evolution process in real time without affecting normal machining, and make timely decisions to adjust machining parameters or replace the tool based on changes in tool status, thereby improving machining stability and quality. Simultaneously, the electrical and control parameters of the ultrasonic vibration system itself can be directly used as monitoring signals, eliminating the need to place additional sensors near the machine tool or tool, effectively reducing system complexity and environmental noise interference, and improving the integration and engineering applicability of tool condition monitoring. This solves the problem that the complex sensor installation, the susceptibility of the signal to environmental noise and changes in working conditions, and the low system integration can easily lead to insufficient stability and reliability of the monitoring signal, making it difficult to achieve accurate and real-time monitoring of tool wear.

[0025] Before describing the tool condition monitoring method based on ultrasonic machining frequency offset of the embodiments of this application, the system structure and application scenarios involved in the embodiments of this application will be described first.

[0026] In some cases, an ultrasonic machining system may include, but is not limited to, an ultrasonic vibration system, a transducer, a magnetostrictive tool holder, and a cutting tool. The ultrasonic vibration system can be used to generate a high-frequency electrical excitation signal and perform amplitude stabilization control and automatic frequency tracking control on it. The transducer can be used to convert the high-frequency electrical excitation signal into mechanical vibration. The magnetostrictive tool holder can be used to transmit and amplify the mechanical vibration and stably couple the ultrasonic vibration to the cutting tool. The cutting tool can contact the workpiece under the action of ultrasonic vibration to perform machining, and changes in its working state will cause changes in the equivalent load of the ultrasonic machining system.

[0027] As a concrete example, such as Figure 1As shown, firstly, in this embodiment, the transducer 101 can be mounted and fixed on the spindle 108 of a CNC (Computer Numerical Control) machining center; secondly, in this embodiment, the tool 103 can be mounted on a magnetostrictive tool holder 102, and the magnetostrictive tool holder 102 is linked to the CNC machining center spindle 108 and nested in the transducer 101. During the machining process, the spindle rotates and feeds at high speed. During the movement, the ultrasonic vibration system 106 can provide the required electrical energy to the magnetostrictive tool holder through the transducer 101 to drive the tool holder to generate ultrasonic frequency mechanical vibration, which is then transmitted to the tool 103. The workpiece material 104 can be fixed on the machine tool table 105 by a tooling fixture. The host computer 107 can be linked and transmit information through the serial port ultrasonic vibration system.

[0028] It can be explained that the resonant vibration can be generated by transmitting current through the ultrasonic vibration system 106 to the transducer 101 and then to the magnetostrictive vibrating tool holder 102, and then to the tool 103 to generate high-frequency vibration, with the direction being longitudinal and the vibration frequency not less than 10kHz.

[0029] Based on the system structure provided in the above embodiments, the tool condition monitoring method based on ultrasonic machining frequency offset of the present application embodiments can be implemented. The tool condition monitoring method based on ultrasonic machining frequency offset of the present application embodiments will be described in detail below.

[0030] Specifically, Figure 2 This is a flowchart illustrating a tool condition monitoring method based on ultrasonic machining frequency offset provided in an embodiment of this application.

[0031] like Figure 2 As shown, the tool condition monitoring method based on ultrasonic machining frequency offset includes the following steps: In step S201, the actual state of the ultrasonic processing system is identified.

[0032] It can be explained that the actual state of an ultrasonic machining system typically includes the operating state determined by the workload, tool condition, and control strategy. This mainly includes, but is not limited to, the resonant or detuned state (reflecting the degree of matching between the current operating frequency and the system's inherent resonant frequency); the amplitude stable or amplitude limited state (reflecting whether amplitude stability control can maintain the set amplitude); and the normal and abnormal machining states (such as abnormal system parameters caused by accelerated tool wear, chipping, adhesion, or sudden changes in workpiece material). These conditions are usually directly reflected in changes in parameters such as the resonant frequency, frequency offset, driving voltage, current, impedance, or phase of the ultrasonic machining system, and can serve as an important basis for tool condition monitoring and machining process evaluation.

[0033] In step S202, in response to the actual state being an unloaded resonant state and an amplitude stable state, the ultrasonic processing system is controlled to perform system frequency tracking in order to obtain the resonant frequency offset of the ultrasonic processing system.

[0034] It can be explained that the no-load resonance state refers to the working state of the ultrasonic machining system where the tool is not in contact with the workpiece and the system is not subjected to cutting load. In this state, the system drive frequency can be controlled, the system resonance frequency point in this state can be found, and the target current value below the resonance frequency point can be determined. The system can then track the system frequency. At the same time, in this state, the system current can automatically converge to the target current and its threshold. The system frequency is controlled in a closed loop according to the current change. The electrical parameters such as the system drive current, phase difference, and equivalent impedance remain stable. The ultrasonic vibration is output with a set amplitude and can be used to characterize the reference resonance characteristics of the system.

[0035] In one embodiment of this application, the amplitude stability state can be determined in real time through the closed-loop control signal of the ultrasonic vibration system itself, without relying on external sensing devices. Specifically, during normal operation, the ultrasonic machining system's drive controller (e.g., a control system based on an FPGA (Field-Programmable Gate Array)) continuously executes a frequency tracking algorithm. The core objective of this algorithm is to maintain the drive current (or the current in the resonant circuit) near a set target value, thereby ensuring that the system always operates at the resonant point and maintains amplitude stability. Therefore, when the amplitude of the drive current fluctuation acquired by the system does not exceed a certain tolerance threshold, and the change in drive frequency within a set time window is less than a frequency convergence threshold, it can be determined that the system has entered an amplitude stable state. Thus, this embodiment of the application can control the ultrasonic machining system to perform system frequency tracking. The resonant frequency offset obtained in this state has a clear physical meaning and can truly reflect the changes in the system's equivalent mechanical parameters caused by changes in tool condition (such as wear or breakage), thereby providing a reliable basis for subsequent tool condition identification.

[0036] Furthermore, embodiments of this application can fully utilize the frequency and current information naturally generated by the ultrasonic system during closed-loop control, transforming it from a simple machining control parameter into a sensing signal of the tool's health status. On one hand, tool breakage can lead to abrupt changes in machining conditions, resulting in a significant change in the resonant frequency. This characteristic can be captured with high sensitivity by monitoring abnormal behavior of frequency offset. On the other hand, as tool wear accumulates, the cutting force gradually increases, causing a continuous shift in the resonant frequency. Embodiments of this application can achieve imperceptible, online prediction of wear status by establishing a mapping relationship between frequency offset, cutting force, and tool wear.

[0037] As one possible approach, the resonant frequency offset in this application embodiment can be obtained based on the electromechanical impedance characteristics of the ultrasonic vibration system in the resonant state. Specifically, this characteristic manifests as follows: when the driving frequency equals the system's mechanical resonant frequency, the electromechanical coupling of the integrated transducer-amplifier-cutter structure reaches its optimal value, and its equivalent circuit exhibits a maximum impedance modulus, thereby generating a minimal driving current under constant voltage excitation. Therefore, the system's resonant state can be indirectly determined by monitoring the current amplitude in the driving circuit.

[0038] In specific implementation, the embodiments of this application can be led by an FPGA controller to control the entire self-sensing process. The FPGA first generates digital waveform instructions to control the DAC module to output an analog voltage signal with a specific amplitude and frequency; this signal is amplified by a power amplifier and then drives the magnetostrictive transducer. Simultaneously, the system collects the drive current at the output of the power amplifier in real time through a high-bandwidth current sensor and feeds this signal back to the FPGA. The FPGA internally runs frequency tracking control logic: continuously comparing the current effective value with a pre-calibrated target current value (corresponding to the peak current in the no-load resonant state); if the detected current is lower than the target value, the DAC output frequency is adjusted in small steps, searching for the resonant point along the direction of current increase; when the current stabilizes within the allowable error range of the target value, and the frequency change is less than a preset convergence threshold within several consecutive control cycles, it is determined that the system has locked the resonant frequency in this state. .

[0039] Ultimately, the FPGA locks the frequency. The no-load resonant frequency measured before construction Perform interpolation to obtain the resonant frequency offset. This offset originates directly from the change in the system's equivalent impedance caused by tool condition (such as wear or fracture), and can be used as a core characteristic parameter for tool health monitoring.

[0040] It can be noted that the entire acquisition process utilizes the ultrasonic system's own voltage / current closed-loop control circuit, without the need for external dedicated sensing devices, thus combining engineering feasibility with technological advancement.

[0041] In step S203, the resonant frequency offset is input to the pre-built tool condition monitoring model to output the current wear amount of the tool and generate the current state of the tool based on the current wear amount.

[0042] In the embodiments of this application, in practical applications, the tool wear monitoring model can be used to establish a mapping relationship between the resonant frequency offset and the tool wear amount. Its specific form can be flexibly selected according to the actual processing conditions and accuracy requirements. For example, an empirical fitting function (such as a polynomial, exponential, or piecewise linear relationship) obtained through offline calibration experiments can be used, or a conventional machine learning regression model (such as support vector regression, random forest, etc.) can be used.

[0043] The current state of the tool can include, but is not limited to, normal state, different degrees of wear, and severe wear or failure state. It can also be represented by the real-time wear amount or remaining life of the tool as a continuous variable. Based on the current state of the tool, it is possible to further realize adaptive adjustment of machining parameters, early warning of machining process risks, and intelligent decision-making on tool replacement timing, thereby improving the stability, machining quality and production efficiency of ultrasonic machining process.

[0044] Optionally, in one embodiment of this application, before inputting the resonant frequency offset into the pre-built tool condition monitoring model, the method further includes: obtaining the training resonant frequency and training wear amount of the ultrasonic machining process; generating a model training set based on the training resonant frequency and training wear amount; and training the model using the model training set based on the relationship between the cutting force and the resonant frequency after the resonant state, until the preset training conditions are met, thereby constructing the tool condition monitoring model.

[0045] Specifically, the embodiments of this application can collect the resonant frequency offset and related parameters during ultrasonic machining at different tool wear stages, and combine the tool wear amount or tool condition obtained by offline or online detection as training labels. After preprocessing and feature extraction of the collected data, a tool condition monitoring model is constructed and parameters are trained and verified, thereby establishing a mapping relationship between the resonant frequency offset and the tool wear condition, providing a basis for online identification of tool condition and estimation of wear amount in subsequent machining processes.

[0046] The preset training conditions can be that when the model's state recognition accuracy or wear prediction error on the validation dataset reaches a set threshold, and the change in model parameters is lower than the set convergence condition in multiple consecutive training iterations, the tool condition monitoring model is determined to have met the training conditions, and this model is used as the target model for subsequent online tool condition monitoring.

[0047] In some cases, the relationship between the resonant frequency and the current amplitude-frequency characteristic can be established from the resonant frequency characteristics of an ultrasonic vibration system, which can be expressed as: , in, For driving current, For resonant current, The resonant frequency; Based on the above relationships, the embodiments of this application can establish a practical relationship between the system vibration amplitude and the driving frequency in a resonant state. According to the vibration model, it can be expressed as: , in, The actual ultrasonic amplitude to be loaded. This is the amplitude proportionality coefficient. Amplification factor of the amplitude transformer For the equivalent damping of the output component, For the equivalent damping of the output component, For mechanical quality factors; In the resonant state, the formula can be simplified to: , Furthermore, based on the system equivalent circuit theory, after equivalencing the mechanical parts, the system resonant impedance formula can be obtained from the embodiments of this application: , in, , For electrical branch resistance and inductance, , The resistance of the secondary coil and the excitation coil, , The inductance of the secondary coil and the excitation coil, , These are the real and imaginary parts of the electromechanical conversion coefficient. Mechanical equivalent resistance Therefore, the resonant current can be obtained as: , As can be seen from the system, the relationship between the system resonant frequency and the external load can be expressed as: , Furthermore, due to the formula: , The simplified formula can be obtained through Taylor expansion: , Therefore, the relationship between cutting force and resonant frequency can be obtained from the embodiments of this application.

[0048] Optionally, in one embodiment of this application, the expression for the relationship between cutting force and resonant frequency can be expressed as: , in, , , , , These represent the average external load (N), the transient theory, the actual ultrasonic amplitude under load, the resonant frequency offset, and the unloaded resonant frequency, respectively.

[0049] It can be explained that, according to the above formula, the cutting load change can be mapped to the resonant frequency offset feature, and combined with the change law of cutting force with tool wear evolution, a quantitative relationship between cutting force and tool wear can be established; on this basis, the cutting force variable can be eliminated to obtain the mapping relationship between tool wear amount and resonant frequency offset, and then a tool condition monitoring model based on resonant frequency offset can be constructed to realize online and real-time monitoring and evaluation of tool wear state.

[0050] Optionally, in one embodiment of this application, the expression for the tool condition monitoring model is: VB = G(Fchange) Where VB represents the tool wear amount, Fchange represents the resonant frequency offset, and G() represents the tool condition monitoring model.

[0051] Through the tool condition monitoring model, the embodiments of this application can directly output the tool wear amount, thereby achieving rapid and real-time assessment of the tool wear condition.

[0052] Furthermore, embodiments of this application can automatically determine the wear stage of the tool—such as the initial wear stage, normal wear stage, or severe wear stage—by comparing the tool wear amount with a set wear threshold or grading rule. Based on this determination, the machining system can trigger corresponding control strategies, such as issuing a tool replacement warning, dynamically adjusting cutting parameters (such as feed rate, ultrasonic amplitude, etc.), or activating a machining process stability compensation mechanism. This effectively avoids a decline in machining quality or equipment malfunction due to excessive tool wear, providing a basis for tool replacement decisions, adaptive adjustment of machining parameters, and machining process stability control.

[0053] The following is a specific example, such as Figure 3 As shown, the tool condition monitoring method based on ultrasonic machining frequency offset of this application embodiment is further explained.

[0054] In step S301, data is acquired.

[0055] This application embodiment can acquire parameters such as voltage, current, and operating frequency during the operation of the ultrasonic processing system through a data acquisition system; wherein, the data includes both offline signal data used for modeling and online signal data acquired in real time during the processing.

[0056] In step S302, the resonance offset is determined.

[0057] Subsequently, the embodiments of this application can perform signal processing on the acquired offline and online signals, including but not limited to filtering, denoising, feature extraction, and steady-state interval screening, to obtain the resonant frequency change characteristics that reflect the working characteristics of the system; based on this, the resonant frequency offset of the ultrasonic processing system relative to the initial resonant state is calculated.

[0058] In step S303, the tool wear amount is determined.

[0059] Meanwhile, the tool wear amount under corresponding working conditions can be obtained through shutdown detection, microscopic measurement or online detection devices in the embodiments of this application.

[0060] In step S304, the relational model is determined.

[0061] In this embodiment, the resonance offset and related machining parameters can be used as model inputs, and the tool wear amount can be used as model outputs. The model can be trained using regression models, machine learning models, or physical mechanism models to obtain a model showing the relationship between the resonance offset and the tool wear amount, thereby enabling tool wear prediction.

[0062] According to the tool condition monitoring method based on ultrasonic machining frequency offset proposed in the embodiments of this application, when the actual state of the ultrasonic machining system is identified as an unloaded resonant state and an amplitude stable state, the ultrasonic machining system is controlled to perform system frequency tracking, and then input into the tool condition monitoring model to output the current state of the tool. The tool wear evolution process can be characterized in real time without affecting normal machining, and machining parameter adjustments or tool replacement decisions can be made in a timely manner according to changes in tool condition, thereby improving machining stability and machining quality. At the same time, the electrical and control parameters of the ultrasonic vibration system itself can be directly used as monitoring signals, eliminating the need to place additional sensors near the machine tool or tool, effectively reducing system complexity and environmental noise interference, and improving the integration and engineering applicability of tool condition monitoring.

[0063] Next, referring to the accompanying drawings, a tool condition monitoring device based on ultrasonic machining frequency offset is described according to an embodiment of this application.

[0064] Figure 4 This is a block diagram of a tool condition monitoring device based on ultrasonic machining frequency offset according to an embodiment of this application.

[0065] like Figure 4 As shown, the tool condition monitoring device 10 based on ultrasonic machining frequency offset includes: an identification module 100, a control module 200, and a monitoring module 300.

[0066] The identification module 100 is used to identify the actual state of the ultrasonic processing system.

[0067] The control module 200 is used to control the ultrasonic processing system to perform system frequency tracking in response to the actual state being an unloaded resonant state and an amplitude stable state, so as to obtain the resonant frequency offset of the ultrasonic processing system.

[0068] The monitoring module 300 is used to input the resonant frequency offset into a pre-built tool condition monitoring model to output the current wear amount of the tool and generate the current state of the tool based on the current wear amount.

[0069] Optionally, in one embodiment of this application, it further includes: an acquisition module, a generation module, and a construction module.

[0070] The acquisition module is used to acquire the training resonant frequency offset and training wear amount during the ultrasonic processing.

[0071] The generation module is used to generate a model training set based on the training resonant frequency offset and the training wear.

[0072] The module is used to train the model based on the relationship between the cutting force and the resonant frequency after the resonant state, using the model training set, until the preset training conditions are met, and to build a tool condition monitoring model.

[0073] Optionally, in one embodiment of this application, the expression for the relationship between cutting force and resonant frequency is: , in, , , , , These represent the average external load (N), the transient theory, the actual ultrasonic amplitude under load, the resonant frequency offset, and the unloaded resonant frequency, respectively.

[0074] Optionally, in one embodiment of this application, the expression for the tool condition monitoring model is: VB = G(Fchange) Where VB represents the tool wear amount, Fchange represents the resonant frequency offset, and G() represents the tool condition monitoring model.

[0075] It should be noted that the foregoing explanation of the tool condition monitoring method based on ultrasonic machining frequency offset also applies to the tool condition monitoring device based on ultrasonic machining frequency offset in this embodiment, and will not be repeated here.

[0076] According to the tool condition monitoring device based on ultrasonic machining frequency offset proposed in the embodiments of this application, when the actual state of the ultrasonic machining system is identified as an unloaded resonant state and an amplitude stable state, the ultrasonic machining system is controlled to perform system frequency tracking to obtain the resonant frequency offset, which is then input into the tool condition monitoring model to output the current state of the tool. This device can characterize the tool wear evolution process in real time without affecting normal machining, and make timely decisions to adjust machining parameters or replace the tool based on changes in the tool condition, thereby improving machining stability and machining quality. At the same time, the electrical and control parameters of the ultrasonic vibration system itself can be directly used as monitoring signals, eliminating the need to place additional sensors near the machine tool or tool, effectively reducing system complexity and environmental noise interference, and improving the integration and engineering applicability of tool condition monitoring.

[0077] Figure 5 A schematic diagram of the structure of an electronic device provided in an embodiment of this application. The electronic device may include: The memory 501, the processor 502, and the computer program stored on the memory 501 and capable of running on the processor 502.

[0078] When the processor 502 executes the program, it implements the tool condition monitoring method based on ultrasonic machining frequency offset provided in the above embodiments.

[0079] Furthermore, electronic devices also include: Communication interface 503 is used for communication between memory 501 and processor 502.

[0080] The memory 501 is used to store computer programs that can run on the processor 502.

[0081] Memory 501 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0082] If the memory 501, processor 502, and communication interface 503 are implemented independently, then the communication interface 503, memory 501, and processor 502 can be interconnected via a bus to complete communication between them. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of representation, Figure 5The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0083] Optionally, in a specific implementation, if the memory 501, processor 502, and communication interface 503 are integrated on a single chip, then the memory 501, processor 502, and communication interface 503 can communicate with each other through an internal interface.

[0084] Processor 502 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of this application.

[0085] This embodiment also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described tool condition monitoring method based on ultrasonic machining frequency offset.

[0086] This application also provides a computer program product, including a computer program that can run computer instructions. When the computer instructions are executed by a processor, they implement the tool condition monitoring method based on ultrasonic machining frequency offset provided in this application.

[0087] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0088] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0089] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or N executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0090] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0091] It should be understood that the various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. If implemented in hardware, as in another embodiment, it can be implemented using any one or more of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0092] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0093] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0094] The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc. Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of this application.

Claims

1. A tool condition monitoring method based on ultrasonic machining frequency shift amount, characterized by, Includes the following steps: Identify the actual state of the ultrasonic processing system; In response to the actual state being an unloaded resonance state and an amplitude stable state, the ultrasonic processing system is controlled to perform system frequency tracking in order to obtain the resonant frequency offset of the ultrasonic processing system. The resonant frequency offset is input into a pre-built tool condition monitoring model to output the current wear amount of the tool, and the current state of the tool is generated based on the current wear amount.

2. The method of claim 1, wherein, Before inputting the resonant frequency offset into the pre-built tool condition monitoring model, the following steps are also included: Obtain the training resonant frequency shift and training wear amount during ultrasonic processing; A model training set is generated based on the training resonant frequency offset and the training wear amount; Based on the relationship between cutting force and resonant frequency after resonance, the model is trained using the model training set until the preset training conditions are met, thus constructing the tool condition monitoring model.

3. The method according to claim 2, characterized in that, The expression for the relationship between the cutting force and the resonant frequency is: ， in, These represent the average external load, the transient theory, the actual ultrasonic amplitude under load, the resonant frequency offset, and the unloaded resonant frequency, respectively.

4. The method according to claim 3, characterized in that, The expression for the tool condition monitoring model is: VB = G(Fchange) Wherein, VB represents the tool wear amount, Fchange represents the resonant frequency offset, and G() represents the tool condition monitoring model.

5. A tool condition monitoring device based on ultrasonic machining frequency offset, characterized in that, include: The identification module is used to identify the actual state of the ultrasonic processing system. The control module is used to control the ultrasonic processing system to perform system frequency tracking in response to the actual state being an unloaded resonance state and an amplitude stable state, so as to obtain the resonant frequency offset of the ultrasonic processing system. The monitoring module is used to input the resonant frequency offset into a pre-built tool condition monitoring model to output the current wear amount of the tool and generate the current state of the tool based on the current wear amount.

6. The apparatus according to claim 5, characterized in that, Also includes: The acquisition module is used to acquire the training resonant frequency offset and training wear amount during the ultrasonic processing. The generation module is used to generate a model training set based on the training resonant frequency offset and the training wear amount; The construction module is used to train the model using the model training set based on the relationship between the cutting force and the resonant frequency after the resonance state, until the preset training conditions are met, and to construct the tool state monitoring model.

7. The apparatus according to claim 6, characterized in that, The expression for the relationship between the cutting force and the resonant frequency is: ， in, , , , , This represents the average external load, transient theory, actual ultrasonic amplitude under load, resonant frequency offset, and no-load resonant frequency.

8. An electronic device, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executing the program to implement the tool condition monitoring method based on ultrasonic machining frequency offset as described in any one of claims 1-4.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, The program is executed by the processor to implement the tool condition monitoring method based on ultrasonic machining frequency offset as described in any one of claims 1-4.

10. A computer program product, comprising a computer program, characterized in that, The computer program is executed to implement the tool condition monitoring method based on ultrasonic machining frequency offset as described in any one of claims 1-4.

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