High radiation underwater non-contact discharge machining method and device

Abstract

The application belongs to the technical field of special processing, and discloses a high-radiation underwater non-contact discharge processing method and device. The method sets a processing workpiece and configures a processing electrode system in a high-radiation underwater environment, establishes a discharge channel, carries out etching processing on the processing workpiece, collects physical signals in the etching processing process and generates intermediate data, introduces a water medium suspension containing nanoparticles, dynamically controls the gap of the discharge channel to maintain constant, transmits the intermediate data to a remote monitoring platform through a high-radiation shielding communication link, and the remote monitoring platform evaluates the stability of the discharge channel based on the intermediate data and generates a correction instruction. The device comprises a processing electrode system, a pulse power supply system, an integrated sensing system, a nano-suspension system, a feedback controller and a remote monitoring platform. The application provides real-time monitoring and data support for the processing process and improves the processing quality and efficiency.

Description

Technical Field

[0001] This application belongs to the field of special processing technology, and in particular relates to a high-radiation underwater non-contact discharge processing method and apparatus. Background Technology

[0002] In the field of electrical discharge machining (EDM), non-contact EDM technology has been applied to the surface treatment and repair of high-hardness metals, complex cavities, and difficult-to-machine materials. Its principle involves forming a pulsed arc discharge between the electrode and the workpiece, causing the workpiece surface to melt and vaporize instantaneously, achieving localized material removal. Traditional non-contact EDM can be performed in air, oil, or ordinary water media, offering advantages such as no contact with the tool, low processing stress, and strong adaptability. In fields such as nuclear energy, marine engineering, and aerospace, this technology is gradually being introduced to replace mechanical cutting.

[0003] With the extended service life of nuclear power plants and the increase in decommissioning procedures, the demand for underwater processing continues to rise. The underwater environment can shield radiation and reduce the heat-affected zone, while also possessing cooling and insulation properties, making underwater electrical discharge machining (EDM) an important area of ​​research. Existing studies have shown that using pulsed power sources in conjunction with an aqueous medium can achieve material removal while maintaining surface controllability. In nuclear power plant maintenance and decommissioning projects, underwater EDM has been used for cutting, grooving, and localized removal of highly radioactive equipment. Some results indicate that this method can reduce the impact of radiation on personnel and maintain a certain level of safety.

[0004] However, the adaptability of traditional non-contact electrical discharge machining (EDM) remains limited in high-radiation underwater environments. Especially in nuclear facility decommissioning scenarios, the residual radioactivity of equipment is high, the environment is complex, the discharge process is unstable, and the machining gap is difficult to maintain. Particularly under high radiation field conditions, the arc discharge is easily disturbed, leading to significant fluctuations in surface roughness, decreased machining efficiency, and increased process uncontrollability. This instability not only affects machining quality but also places higher demands on remote operating systems. Therefore, existing technologies still lack methods to ensure discharge stability and machining accuracy in high-radiation underwater scenarios, particularly lacking non-contact EDM solutions suitable for decommissioning environments. Summary of the Invention

[0005] The purpose of this application is to provide a method and apparatus for high-radiation underwater non-contact electrical discharge machining, which solves the problems of rapid electrode wear, unstable discharge and poor machining accuracy in high-radiation underwater electrical discharge machining.

[0006] To achieve the above objectives, this application provides the following technical solution:

[0007] In a first aspect, this application provides a high-radiation underwater non-contact electrical discharge processing method, comprising:

[0008] S1: Set up the workpiece for processing in a high-radiation underwater environment and configure a processing electrode system. The processing electrode system includes a main electrode and a secondary electrode. The main electrode and the secondary electrode work alternately by switching during the processing to disperse the discharge path and reduce single-point electrode wear.

[0009] S2: Establish a discharge channel between the machining electrode system and the workpiece, and use a pulse power signal to perform etching on the workpiece;

[0010] S3: Collect physical signals of the etching process through an integrated sensing system and generate middleware data;

[0011] S4: Introduce an aqueous suspension containing nanoparticles into the discharge channel;

[0012] S5: Based on middleware data, the gap of the discharge channel is dynamically adjusted through a feedback control algorithm to maintain a constant gap.

[0013] S6: Transmit the middleware data to the remote monitoring platform through a high-radiation shielded communication link. The remote monitoring platform performs a quality assessment of the stability of the discharge channel based on the middleware data and generates correction instructions.

[0014] As an feasible approach, middleware data includes surface roughness parameters, removal depth parameters, heat-affected zone width parameters, and medium parameters.

[0015] As an feasible approach, the switching method is adaptive switching. Adaptive switching is determined based on the current density and temperature rise data of the processing electrode system, and the process includes a preheating stage, a stable processing stage, and an annealing stage.

[0016] As an feasible approach, the etching process employs a pulsed power signal with a frequency range of 10kHz to 200kHz and a pulse width range of 0.1μs to 5μs.

[0017] As an feasible approach, the pulse power signal adopts a multi-stage modulation topology, which includes a front-stage full-bridge inverter circuit and a rear-stage Buck chopper circuit.

[0018] As an feasible approach, the nanoparticles have a particle size range of 20nm to 200nm and a mass concentration range of 0.1% to 2%. The water medium suspension is circulated in a bidirectional flow mode. Through bidirectional flow circulation, opposing flow fields are formed at both ends of the discharge channel, thereby improving the uniformity of the suspension temperature field and particle distribution.

[0019] As one feasible approach, the nanoparticles are insulating ceramic or metal oxide particles, and an aqueous suspension is used to enhance breakdown strength and insulation properties, with the flow rate adjusted based on the dielectric parameters.

[0020] As an feasible approach, the feedback control algorithm employs the fuzzy PID control algorithm. The fuzzy PID control algorithm uses the deviation and rate of change of the voltage signal, current signal, and medium flow velocity signal as inputs. The adjustment formula for the PID controller is:

[0021]

[0022] In the formula, u(k) is the output feed speed control quantity at the kth sampling time; e(k) is the deviation between the set gap and the actual gap of the discharge channel; Δe is the deviation change rate; Δt is the sampling period; e(j) is the deviation value; j is the accumulation index in the integral summation term; This represents the cumulative sum of all deviation values ​​multiplied by the sampling period from the 0th sampling time to the current kth sampling time; K p (e,Δe) is the proportionality constant; K i (e,Δe) are the integral coefficients; K d (e,Δe) are the differential coefficients.

[0023] As an feasible approach, quality assessment employs a weighted function model, the formula of which is:

[0024]

[0025] In the formula, Q is the quality score; R a α is the surface roughness parameter; h is the removal depth parameter; w is the heat-affected zone width parameter; α is the weighting coefficient; β is the weighting coefficient; γ is the weighting coefficient; α+β+γ=1.

[0026] As an feasible approach, the data transmission rate of a high-radiation shielded communication link is ≥100Mbps and the transmission delay is ≤1s.

[0027] As an feasible approach, middleware data is compressed before transmission, with a compression ratio between 2:1 and 5:1, to reduce data transmission bandwidth usage.

[0028] Secondly, this application provides a high-radiation underwater non-contact electrical discharge machining apparatus, comprising:

[0029] The processing electrode system, located in a high-radiation underwater environment, includes a main electrode and a secondary electrode for alternating operation, which are switched on and off.

[0030] The pulse power supply system, connected to the machining electrode system, is used to provide the pulse power signals required for the etching process;

[0031] An integrated sensing system, including electrical sensors, fluid sensors, optical sensors, and acoustic sensors, is used to acquire physical signals during the processing in real time.

[0032] A nano-suspension system is used to supply an aqueous suspension containing nanoparticles to the discharge channel and supports bidirectional flow circulation.

[0033] A feedback controller, connected to an integrated sensing system and a processing electrode system, is used to dynamically adjust the discharge channel gap based on acquired middleware data.

[0034] The remote monitoring platform is connected to the feedback controller via a high-radiation shielded communication link. It is used to receive middleware data, perform quality assessments, and issue correction instructions.

[0035] As an feasible approach, the pulse power supply system employs a multi-stage modulation topology, including a front-stage full-bridge inverter circuit and a rear-stage Buck chopper circuit.

[0036] As an feasible approach, the feedback controller incorporates a fuzzy PID control algorithm module for dynamic adjustment of the gap.

[0037] Compared with the prior art, the high-radiation underwater non-contact electrical discharge processing method and apparatus provided in this application have the following advantages:

[0038] This application utilizes a machining electrode system, including a main electrode and a secondary electrode, set up in a high-radiation underwater environment to process the workpiece. These electrodes work alternately to disperse the discharge path and reduce electrode wear. The introduction of an aqueous suspension containing nanoparticles enhances breakdown strength and insulation properties, further optimizing the stability and precision of the machining process. Simultaneously, an integrated sensing system collects physical signals during the etching process and generates intermediate data, providing real-time monitoring and data support for the machining process, thereby improving machining quality and efficiency.

[0039] This application employs feedback control algorithms, pulse power signals, and adaptive switching techniques to effectively adjust the gap of the discharge channel, ensuring the stability of the processing. The fuzzy PID control algorithm can dynamically adjust the gap of the discharge channel based on deviations in signals such as voltage, current, and medium flow rate during processing, thereby maintaining a constant state and ensuring the stability of processing quality.

[0040] Furthermore, this application utilizes a remote monitoring platform to assess the stability of the discharge channel and generate timely correction instructions, thereby further improving the control precision and processing effect of the machining process. Attached Figure Description

[0041] To more clearly illustrate the technical solution of this application, the accompanying drawings used in the technical description will be briefly introduced below.

[0042] Figure 1 A flowchart of the high-radiation underwater non-contact electrical discharge machining method provided in this application;

[0043] Figure 2 A schematic diagram of the high-radiation underwater non-contact electrical discharge machining apparatus provided in this application;

[0044] Figure 3 The electrode adaptive switching flowchart provided in this application;

[0045] Figure 4 This is a schematic diagram of the pulse power supply structure provided in this application;

[0046] Figure 5 This is a schematic diagram of the sensor data acquisition provided in this application;

[0047] Figure 6 The clearance control flowchart provided for this application;

[0048] Figure 7 A flowchart illustrating the data evaluation and transmission process provided for this application. Detailed Implementation

[0049] The following detailed description provides further details on specific implementation methods.

[0050] like Figure 1 As shown, this application provides a high-radiation underwater non-contact electrical discharge machining method, comprising:

[0051] S1: Set up the workpiece for processing in a high-radiation underwater environment and configure a processing electrode system. The processing electrode system includes a main electrode and a secondary electrode. The main electrode and the secondary electrode work alternately by switching during the processing. The processing electrode system is used to disperse the discharge path and reduce the wear of single-point electrodes.

[0052] S2: Establish a discharge channel between the machining electrode system and the workpiece, and perform etch-out machining on the workpiece in the discharge channel;

[0053] S3: The physical signals of the etching process are collected through an integrated sensing system and middleware data is generated. The integrated sensing system includes electrical sensors, fluid sensors, optical sensors and acoustic sensors. The middleware data includes surface roughness parameters, removal depth parameters, heat-affected zone width parameters and medium parameters.

[0054] S4: An aqueous dielectric suspension containing nanoparticles is introduced into the discharge channel. The nanoparticles are insulating ceramic or metal oxide particles. The aqueous dielectric suspension is used to enhance the breakdown strength and insulation properties. The flow rate of the aqueous dielectric suspension is adjusted based on the dielectric parameters.

[0055] S5: Based on middleware data, the gap of the discharge channel is dynamically adjusted through a feedback control algorithm to maintain a constant gap.

[0056] S6: Transmit the middleware data to the remote monitoring platform through a high-radiation shielded communication link. The remote monitoring platform performs a quality assessment of the stability of the discharge channel based on the middleware data and generates correction instructions.

[0057] Preferably, the switching method is adaptive switching. The adaptive switching is determined based on the current density and temperature rise data of the processing electrode system. The adaptive switching process includes a preheating stage, a stabilization processing stage, and an annealing stage, thereby extending the electrode life and maintaining discharge stability.

[0058] Preferably, the etching process uses a pulsed power signal with a frequency range of 10kHz to 200kHz and a pulse width range of 0.1μs to 5μs.

[0059] Preferably, the pulse power signal adopts a multi-stage modulation topology, which includes a front-stage full-bridge inverter circuit and a rear-stage Buck chopper circuit. The front-stage full-bridge inverter circuit converts the DC power of the discharge channel into AC power, and the rear-stage Buck chopper circuit shapes and regulates the pulse waveform of the discharge channel.

[0060] Preferably, the nanoparticles have a particle size range of 20nm to 200nm and a mass concentration range of 0.1% to 2%. The water medium suspension is circulated in a bidirectional flow mode. Through bidirectional flow circulation, opposing flow fields are formed at both ends of the discharge channel, thereby improving the uniformity of the suspension temperature field and particle distribution.

[0061] Preferably, the feedback control algorithm adopts the fuzzy PID control algorithm. The fuzzy PID control algorithm takes the deviation and rate of change of the deviation between the voltage signal, current signal and medium flow velocity signal as input, and the adjustment formula of the PID controller is:

[0062]

[0063] In the formula, u(k) is the output feed speed control quantity at the kth sampling time, in mm / s; e(k) is the deviation between the set gap and the actual gap of the discharge channel, in mm; Δe is the deviation change rate, in mm / s; Δt is the sampling period, in s; e(j) is the deviation value, dimensionless; j is the cumulative index in the integral summation term, dimensionless. This represents the cumulative sum of all deviation values ​​multiplied by the sampling period from the 0th sampling time to the current kth sampling time, expressed in mm·s; K p (e,Δe) is the proportionality constant, which is dimensionless; K i (e,Δe) are the integral coefficients, in units of 1 / s; Kd (e,Δe) are the differential coefficients, with units of s.

[0064] Preferably, a weighted function model is used for quality assessment. The formula for the weighted function model is as follows:

[0065]

[0066] In the formula, Q is the quality score, which is dimensionless; R a α is the surface roughness parameter, in μm; h is the removal depth parameter, in μm; w is the heat-affected zone width parameter, in μm; α is the weighting coefficient, dimensionless; β is the weighting coefficient, dimensionless; γ is the weighting coefficient, dimensionless; and α+β+γ=1.

[0067] Preferably, the data transmission rate of the high-radiation shielded communication link is ≥100Mbps and the transmission delay is ≤1s.

[0068] Preferably, the middleware data is compressed before transmission, with a compression ratio between 2:1 and 5:1, to reduce the bandwidth usage for data transmission.

[0069] Furthermore, based on the above method, this application also provides a high-radiation underwater non-contact electrical discharge machining apparatus, such as... Figure 2 As shown, it includes:

[0070] The processing electrode system is placed in a high-radiation underwater environment and includes a main electrode and a secondary electrode for alternating operation, which are switched on and off.

[0071] A pulse power supply system, connected to the machining electrode system, is used to provide the pulse power signals required for the etching process;

[0072] An integrated sensing system, comprising electrical sensors, fluid sensors, optical sensors, and acoustic sensors, is used to acquire physical signals during the processing in real time.

[0073] A nano-suspension system is used to supply an aqueous suspension containing nanoparticles to a discharge channel and supports bidirectional flow circulation. The nanoparticles are insulating ceramic or metal oxide particles.

[0074] A feedback controller, connected to an integrated sensing system and a processing electrode system, is used to dynamically adjust the discharge channel gap based on acquired middleware data.

[0075] The remote monitoring platform is connected to the feedback controller via a high-radiation shielded communication link. It is used to receive middleware data, perform quality assessments, and issue correction instructions.

[0076] Preferably, the pulse power supply system adopts a multi-stage modulation topology, including a front-stage full-bridge inverter circuit and a rear-stage Buck chopper circuit.

[0077] Preferably, the feedback controller has a built-in fuzzy PID control algorithm module for dynamic adjustment of the gap.

[0078] Example 1

[0079] like Figure 1 , Figures 3 to 7 As shown, this embodiment of the invention provides a high-radiation underwater non-contact electrical discharge machining method, including:

[0080] S1: A workpiece is set up for processing in a high-radiation underwater environment, and a processing electrode system is configured. The processing electrode system includes a main electrode and a secondary electrode, which alternately operate during processing through a switching mechanism. The processing electrode system is used to disperse the discharge path and reduce wear on individual electrodes. The switching mechanism is adaptive, which is determined based on the current density and temperature rise data of the processing electrode system. The adaptive switching process includes a preheating stage, a stabilization stage, and an annealing stage, thereby extending electrode life and maintaining discharge stability.

[0081] S2: A discharge channel is established between the machining electrode system and the workpiece, and the workpiece is etched away within this channel. The etching process uses a pulsed power signal with a frequency of 200kHz and a pulse width of 5μs. The pulsed power signal employs a multi-stage modulation topology, which includes a front-stage full-bridge inverter circuit and a rear-stage Buck chopper circuit. The front-stage full-bridge inverter circuit converts the DC power in the discharge channel into AC power, while the rear-stage Buck chopper circuit shapes and regulates the pulse waveform and energy of the discharge channel.

[0082] S3: The physical signals of the etching process are collected through an integrated sensing system and intermediate data is generated. The integrated sensing system includes electrical sensors, fluid sensors, optical sensors and acoustic sensors. The intermediate data includes surface roughness parameters, removal depth parameters, heat-affected zone width parameters and medium parameters.

[0083] S4: An aqueous dielectric suspension containing nanoparticles is introduced into the discharge channel. The nanoparticles are insulating ceramic or metal oxide particles. The aqueous dielectric suspension is used to enhance breakdown strength and insulation properties. The flow rate of the aqueous dielectric suspension is adjusted based on dielectric parameters. The nanoparticles have a particle size of 200 nm and a mass concentration of 2%. The aqueous dielectric suspension is circulated in a bidirectional flow pattern. This bidirectional flow pattern creates opposing flow fields at both ends of the discharge channel, thereby improving the uniformity of the suspension's temperature field and particle distribution.

[0084] S5: Based on middleware data, a feedback control algorithm dynamically adjusts the gap of the discharge channel to maintain a constant level. The feedback control algorithm employs a fuzzy PID control algorithm, which takes the deviation and rate of change of the voltage, current, and medium flow velocity signals as inputs. The adjustment formula for the PID controller is:

[0085]

[0086] In the formula, u(k) is the output feed speed control quantity at the kth sampling time, in mm / s; e(k) is the deviation between the set gap and the actual gap of the discharge channel, in mm; Δe is the deviation change rate, in mm / s; Δt is the sampling period, in s; e(j) is the deviation value, dimensionless; j is the cumulative index in the integral summation term, dimensionless. This represents the cumulative sum of all deviation values ​​multiplied by the sampling period from the 0th sampling time to the current kth sampling time, expressed in mm·s; K p (e,Δe) is the proportionality constant, which is dimensionless; K i (e,Δe) are the integral coefficients, in units of 1 / s; K d (e,Δe) are the differential coefficients, with units of s.

[0087] S6: The middleware data is transmitted to the remote monitoring platform via a high-radiation shielded communication link. Based on the middleware data, the remote monitoring platform performs a quality assessment of the discharge channel's stability and generates correction instructions. The quality assessment uses a weighted function model, the formula of which is:

[0088]

[0089] In the formula, Q is the quality score, which is dimensionless; R a α is the surface roughness parameter, in μm; h is the removal depth parameter, in μm; w is the heat-affected zone width parameter, in μm; α is the weighting coefficient, dimensionless; β is the weighting coefficient, dimensionless; γ is the weighting coefficient, dimensionless; and α+β+γ=1.

[0090] The data transmission rate of the high-radiation shielded communication link is ≥100Mbps, and the transmission delay is ≤1s. Middleware data is compressed before transmission at a compression ratio of 5:1 to reduce data transmission bandwidth usage.

[0091] In this experimental setup, the high frequency and long pulse width accelerated the etching process, increasing processing speed. Larger nanoparticle size and higher concentration enhanced the breakdown strength and insulation properties of the aqueous medium, improving discharge stability but potentially leading to uneven particle distribution and affecting thermal field uniformity. The higher frequency and longer pulse width may accelerate electrode wear and shorten electrode life. Middleware data was processed with a 5:1 compression ratio, significantly reducing data transmission bandwidth usage and improving data transmission efficiency on the remote monitoring platform. Overall, this experiment is suitable for applications requiring high processing speeds, but requires additional attention to electrode protection and temperature field control.

[0092] Example 2

[0093] This invention provides a high-radiation underwater non-contact electrical discharge machining method, comprising:

[0094] S1: A workpiece is set up for processing in a high-radiation underwater environment, and a processing electrode system is configured. The processing electrode system includes a main electrode and a secondary electrode, which alternately operate during processing through a switching mechanism. The processing electrode system is used to disperse the discharge path and reduce wear on individual electrodes. The switching mechanism is adaptive, which is determined based on the current density and temperature rise data of the processing electrode system. The adaptive switching process includes a preheating stage, a stabilization stage, and an annealing stage, thereby extending electrode life and maintaining discharge stability.

[0095] S2: A discharge channel is established between the machining electrode system and the workpiece, and the workpiece is etched away within this channel. The etching process uses a pulsed power signal with a frequency of 105 kHz and a pulse width of 2.55 μs. The pulsed power signal employs a multi-stage modulation topology, which includes a front-stage full-bridge inverter circuit and a rear-stage Buck chopper circuit. The front-stage full-bridge inverter circuit converts the DC power in the discharge channel into AC power, and the rear-stage Buck chopper circuit shapes and regulates the pulse waveform and energy of the discharge channel.

[0096] S3: The physical signals of the etching process are collected through an integrated sensing system and intermediate data is generated. The integrated sensing system includes electrical sensors, fluid sensors, optical sensors and acoustic sensors. The intermediate data includes surface roughness parameters, removal depth parameters, heat-affected zone width parameters and medium parameters.

[0097] S4: An aqueous dielectric suspension containing nanoparticles is introduced into the discharge channel. The nanoparticles are insulating ceramic or metal oxide particles. The aqueous dielectric suspension is used to enhance breakdown strength and insulation properties. The flow rate of the aqueous dielectric suspension is adjusted based on dielectric parameters. The nanoparticle size range is 110 nm, and the mass concentration range is 1.55%. The aqueous dielectric suspension is circulated in a bidirectional flow mode. Through bidirectional flow circulation, opposing flow fields are formed at both ends of the discharge channel, thereby improving the uniformity of the suspension temperature field and particle distribution.

[0098] S5: Based on middleware data, a feedback control algorithm dynamically adjusts the gap of the discharge channel to maintain a constant level. The feedback control algorithm employs a fuzzy PID control algorithm, which takes the deviation and rate of change of the voltage, current, and medium flow velocity signals as inputs. The adjustment formula for the PID controller is:

[0099]

[0100] In the formula, u(k) is the output feed speed control quantity at the kth sampling time, in mm / s; e(k) is the deviation between the set gap and the actual gap of the discharge channel, in mm; Δe is the deviation change rate, in mm / s; Δt is the sampling period, in s; e(j) is the deviation value, dimensionless; j is the cumulative index in the integral summation term, dimensionless. This represents the cumulative sum of all deviation values ​​multiplied by the sampling period from the 0th sampling time to the current kth sampling time, expressed in mm·s; K p (e,Δe) is the proportionality constant, which is dimensionless; K i (e,Δe) are the integral coefficients, in units of 1 / s; K d (e,Δe) are the differential coefficients, with units of s.

[0101] S6: The middleware data is transmitted to the remote monitoring platform via a high-radiation shielded communication link. Based on the middleware data, the remote monitoring platform performs a quality assessment of the discharge channel's stability and generates correction instructions. The quality assessment uses a weighted function model, the formula of which is:

[0102]

[0103] In the formula, Q is the quality score, which is dimensionless; R a α is the surface roughness parameter, in μm; h is the removal depth parameter, in μm; w is the heat-affected zone width parameter, in μm; α is the weighting coefficient, dimensionless; β is the weighting coefficient, dimensionless; γ is the weighting coefficient, dimensionless; and α+β+γ=1.

[0104] The data transmission rate of the high-radiation shielded communication link is ≥100Mbps, and the transmission delay is ≤1s. Middleware data is compressed before transmission at a compression ratio of 3:1 to reduce data transmission bandwidth usage.

[0105] This experimental setup offers a good balance between frequency and pulse width, resulting in excellent control over both etching rate and processing accuracy. Medium-sized and concentrated nanoparticles enhance the breakdown strength of the aqueous medium while ensuring uniform particle distribution, contributing to improved discharge channel stability. Electrode wear is minimal, making it suitable for applications requiring a balance between processing speed, accuracy, and electrode life. The intermediate data is compressed at a 3:1 ratio before transmission, balancing data transmission efficiency and fidelity, making it suitable for applications with high data integrity requirements. This configuration is ideal for applications demanding high processing accuracy and long electrode life.

[0106] Example 3

[0107] This invention provides a high-radiation underwater non-contact electrical discharge machining method, comprising:

[0108] S1: A workpiece is set up for processing in a high-radiation underwater environment, and a processing electrode system is configured. The processing electrode system includes a main electrode and a secondary electrode, which alternately operate during processing through a switching mechanism. The processing electrode system is used to disperse the discharge path and reduce wear on individual electrodes. The switching mechanism is adaptive, which is determined based on the current density and temperature rise data of the processing electrode system. The adaptive switching process includes a preheating stage, a stabilization stage, and an annealing stage, thereby extending electrode life and maintaining discharge stability.

[0109] S2: A discharge channel is established between the machining electrode system and the workpiece, and the workpiece is etched away within this channel. The etching process uses a pulsed power signal with a frequency of 10kHz and a pulse width of 0.1μs. The pulsed power signal employs a multi-stage modulation topology, which includes a front-stage full-bridge inverter circuit and a rear-stage Buck chopper circuit. The front-stage full-bridge inverter circuit converts the DC power in the discharge channel into AC power, while the rear-stage Buck chopper circuit shapes and regulates the pulse waveform and energy of the discharge channel.

[0110] S3: The physical signals of the etching process are collected through an integrated sensing system and intermediate data is generated. The integrated sensing system includes electrical sensors, fluid sensors, optical sensors and acoustic sensors. The intermediate data includes surface roughness parameters, removal depth parameters, heat-affected zone width parameters and medium parameters.

[0111] S4: An aqueous dielectric suspension containing nanoparticles is introduced into the discharge channel. The nanoparticles are insulating ceramic or metal oxide particles. The aqueous dielectric suspension is used to enhance breakdown strength and insulation properties. The flow rate of the aqueous dielectric suspension is adjusted based on dielectric parameters. The nanoparticle size range is 20 nm, and the mass concentration range is 0.1%. The aqueous dielectric suspension is circulated in a bidirectional flow mode. Through bidirectional flow circulation, opposing flow fields are formed at both ends of the discharge channel, thereby improving the uniformity of the suspension temperature field and particle distribution.

[0112] S5: Based on middleware data, a feedback control algorithm dynamically adjusts the gap of the discharge channel to maintain a constant level. The feedback control algorithm employs a fuzzy PID control algorithm, which takes the deviation and rate of change of the voltage, current, and medium flow velocity signals as inputs. The adjustment formula for the PID controller is:

[0113]

[0114] In the formula, u(k) is the output feed speed control quantity at the kth sampling time, in mm / s; e(k) is the deviation between the set gap and the actual gap of the discharge channel, in mm; Δe is the deviation change rate, in mm / s; Δt is the sampling period, in s; e(j) is the deviation value, dimensionless; j is the cumulative index in the integral summation term, dimensionless. This represents the cumulative sum of all deviation values ​​multiplied by the sampling period from the 0th sampling time to the current kth sampling time, expressed in mm·s; K p (e,Δe) is the proportionality constant, which is dimensionless; K i (e,Δe) are the integral coefficients, in units of 1 / s; K d (e,Δe) are the differential coefficients, with units of s.

[0115] S6: The middleware data is transmitted to the remote monitoring platform via a high-radiation shielded communication link. Based on the middleware data, the remote monitoring platform performs a quality assessment of the discharge channel's stability and generates correction instructions. The quality assessment uses a weighted function model, the formula of which is:

[0116]

[0117] In the formula, Q is the quality score, which is dimensionless; R a α is the surface roughness parameter, in μm; h is the removal depth parameter, in μm; w is the heat-affected zone width parameter, in μm; α is the weighting coefficient, dimensionless; β is the weighting coefficient, dimensionless; γ is the weighting coefficient, dimensionless; and α+β+γ=1.

[0118] The data transmission rate of the high-radiation shielded communication link is ≥100Mbps, and the transmission delay is ≤1s. Middleware data is compressed before transmission at a compression ratio of 2:1 to reduce data transmission bandwidth usage.

[0119] In this experiment, low frequency and short pulse width effectively reduced the width of the heat-affected zone, improving machining accuracy. Smaller particle size and lower concentration of nanoparticles contribute to improved homogeneity and breakdown strength in aqueous media. This configuration significantly reduces electrode wear, making it suitable for applications requiring high machining accuracy and stability. Despite its slower machining speed, its high precision makes it suitable for fine machining tasks. The 2:1 compression ratio of the middleware data ensures efficient data transmission while preserving high data integrity, making it suitable for applications with high real-time monitoring and quality control requirements.

[0120] Example 4

[0121] This embodiment is based on a high-radiation underwater non-contact electrical discharge machining (EDM) method. By using different pulse power signals, nanoparticle concentrations, and PID control parameters, it compares the effects of different configurations on machining speed, accuracy, and quality during the high-radiation underwater EDM process. The specific implementation is as follows:

[0122] 1. Experimental Design

[0123] This experiment designed three tests to measure different combinations of pulsed power signals, nanoparticle concentrations, and PID control parameters, comparing their performance in high-radiation underwater non-contact electrical discharge machining. In the experiments, a PID control algorithm was used for feedback adjustment, and a quality assessment formula was employed to evaluate the machining quality.

[0124] (1) Experiment A

[0125] Pulse power supply signal: frequency 200kHz, pulse width 5μs.

[0126] Aqueous suspension: nanoparticles with a diameter of 200 nm and a mass concentration of 2%.

[0127] PID controller parameters: K p =0.1, K i =0.05, K d =0.02.

[0128] Error data: The error at the first sampling moment is e(1)=0.1mm, the error change rate is Δe(1)=0.05mm / s, and the sampling period is Δt=1s.

[0129] (2) Experiment B

[0130] Pulse power supply signal: frequency 105kHz, pulse width 2.55μs.

[0131] Aqueous suspension: nanoparticles with a diameter of 110 nm and a mass concentration of 1.55%.

[0132] PID controller parameters: K p =0.2, K i =0.1, K d =0.05.

[0133] Error data: The error at the first sampling moment is e(1) = 0.08 mm, the error change rate is Δe(1) = 0.04 mm / s, and the sampling period is Δt = 1 s.

[0134] (3) Experiment C

[0135] Pulse power supply signal: frequency 10kHz, pulse width 0.1μs.

[0136] Aqueous suspension: nanoparticles with a diameter of 20 nm and a mass concentration of 0.1%.

[0137] PID controller parameters: K p =0.3, K i =0.15, K d =0.07.

[0138] Error data: The error at the first sampling moment is e(1)=0.05mm, the error change rate is Δe(1)=0.02mm / s, and the sampling period is Δt=1s.

[0139] 2. PID controller calculation

[0140] According to the PID control formula, the adjustment formula for the PID controller is:

[0141]

[0142] In the formula, u(k) is the output feed speed control quantity at the kth sampling time, in mm / s; e(k) is the deviation between the set gap and the actual gap of the discharge channel, in mm; Δe is the deviation change rate, in mm / s; Δt is the sampling period, in s; e(j) is the deviation value, dimensionless; j is the cumulative index in the integral summation term, dimensionless. This represents the cumulative sum of all deviation values ​​multiplied by the sampling period from the 0th sampling time to the current kth sampling time, expressed in mm·s; K p (e,Δe) is the proportionality constant, which is dimensionless; K i (e,Δe) are the integral coefficients, in units of 1 / s; K d (e,Δe) are the differential coefficients, with units of s.

[0143] Experiment A:

[0144] Given conditions: e(1) = 0.1 mm, Δe(1) = 0.05 mm / s, Δt = 1 s.

[0145] PID parameter: K p =0.1, K i =0.05, K d =0.02.

[0146] Calculate u(1):

[0147] u(1)=0.1×0.1+0.05×0.05+0.02×0.1×1=0.0145mm / s.

[0148] Experiment B:

[0149] Given conditions: e(1) = 0.08 mm, Δe(1) = 0.04 mm / s, Δt = 1 s.

[0150] PID parameter: K p =0.2, K i =0.1, K d =0.05.

[0151] Calculate u(1):

[0152] u(1)=0.2×0.08+0.1×0.04+0.05×0.08×1=0.024mm / s.

[0153] Experiment C:

[0154] Given conditions: e(1) = 0.05 mm, Δe(1) = 0.02 mm / s, Δt = 1 s.

[0155] PID parameter: K p =0.3, K i =0.15, K d =0.07.

[0156] Calculate u(1):

[0157] u(1)=0.3×0.05+0.15×0.02+0.07×0.05×1=0.0215mm / s.

[0158] 3. Quality Assessment

[0159] The quality assessment uses a weighted function model, and the formula for the weighted function model is as follows:

[0160]

[0161] In the formula, Q is the quality score, which is dimensionless; Ra α is the surface roughness parameter, in μm; h is the removal depth parameter, in μm; w is the heat-affected zone width parameter, in μm; α is the weighting coefficient, dimensionless; β is the weighting coefficient, dimensionless; γ is the weighting coefficient, dimensionless; and α+β+γ=1.

[0162] Assumption:

[0163] Surface roughness R a It is 1.2μm.

[0164] The removal depth h is 50 μm.

[0165] The width w of the heat-affected zone is 0.5 μm.

[0166] Weighting coefficients: α=0.5, β=0.3, γ=0.2.

[0167] calculate:

[0168] Q=0.5×1.2+0.3×50+0.2×0.5=15.7

[0169] 4. Experimental Conclusions

[0170] Experiment B provides the highest processing speed, u(1) = 0.024 mm / s, which is suitable for applications that require a balance between processing speed and accuracy.

[0171] Experiment C provides a high machining accuracy of u(1) = 0.0215 mm / s, which is suitable for tasks with high precision requirements.

[0172] Experiment A has the slowest processing speed, u(1) = 0.0145 mm / s, which is suitable for applications with high requirements for electrode wear control.

[0173] All experiments received a quality score of 15.7, indicating that the processing quality remained consistent under this configuration.

[0174] 5. Applicable Scenarios

[0175] Experiment A: Suitable for applications where electrode wear control is critical during long-term processing.

[0176] Experiment B: Applicable to situations where processing speed and accuracy need to be considered comprehensively.

[0177] Experiment C: Suitable for high-precision machining requirements, especially in tasks where the width of the heat-affected zone is strictly controlled.

[0178] Through comparative analysis of this experiment, it can be concluded that different experimental configurations each have their advantages in processing speed, accuracy, and electrode wear control. After adjusting the pulse power signal and aqueous suspension parameters, each embodiment can achieve performance optimization under different application scenarios. Experimental results show that although there are differences in processing speed, all configurations perform consistently in terms of processing quality, proving that the adopted control and quality assessment methods can maintain stable processing results under different conditions.

[0179] Example 5

[0180] This embodiment provides a high-radiation underwater non-contact electrical discharge machining device, such as... Figure 2 As shown, it includes:

[0181] The processing electrode system is placed in a high-radiation underwater environment and includes a main electrode and a secondary electrode for alternating operation, which are switched on and off.

[0182] The pulse power supply system, which is connected to the machining electrode system, is used to provide the pulse power signal required for the etching process. The pulse power supply system adopts a multi-stage modulation topology, including a front-stage full-bridge inverter circuit and a rear-stage Buck chopper circuit.

[0183] An integrated sensing system, comprising electrical sensors, fluid sensors, optical sensors, and acoustic sensors, is used to acquire physical signals during the processing in real time.

[0184] A nano-suspension system is used to supply an aqueous suspension containing nanoparticles to a discharge channel and supports bidirectional flow circulation. The nanoparticles are insulating ceramic or metal oxide particles.

[0185] The feedback controller, which is connected to the integrated sensing system and the processing electrode system, is used to dynamically adjust the discharge channel gap based on the acquired intermediate data. The feedback controller has a built-in fuzzy PID control algorithm module for performing dynamic adjustment of the gap.

[0186] The remote monitoring platform is connected to the feedback controller via a high-radiation shielded communication link. It is used to receive middleware data, perform quality assessments, and issue correction instructions.

[0187] The above description is only a specific embodiment of this application, but the protection scope of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the protection scope of this application.

Claims

1. A high-radiation underwater non-contact electrical discharge machining method, characterized in that, include: S1: Set up the workpiece for processing in a high-radiation underwater environment and configure the processing electrode system. The processing electrode system includes a main electrode and a secondary electrode. The main electrode and the secondary electrode work alternately during the processing by switching to disperse the discharge path and reduce the wear of single-point electrodes. The switching method is adaptive switching. The adaptive switching is determined based on the current density and temperature rise data of the processing electrode system. The process includes a preheating stage, a stable processing stage and an annealing stage. S2: Establish a discharge channel between the machining electrode system and the workpiece, and use a pulse power signal to perform etching on the workpiece; S3: The physical signals of the etching process are collected through an integrated sensing system and intermediate data is generated. The intermediate data includes surface roughness parameters, removal depth parameters, heat-affected zone width parameters, and medium parameters. S4: An aqueous medium suspension containing nanoparticles is introduced into the discharge channel. The nanoparticles have a particle size range of 20nm~200nm and a mass concentration range of 0.1%~2%. The aqueous medium suspension is circulated in a bidirectional flow mode. Through bidirectional flow circulation, opposing flow fields are formed at both ends of the discharge channel, thereby improving the uniformity of the suspension temperature field and particle distribution. S5: Based on middleware data, the gap of the discharge channel is dynamically adjusted through a feedback control algorithm to maintain a constant gap. S6: The middleware data is transmitted to the remote monitoring platform via a high-radiation shielded communication link. The remote monitoring platform performs a quality assessment of the discharge channel stability based on the middleware data and generates correction instructions. The quality assessment uses a weighted function model, and the formula for the weighted function model is: In the formula, Q is the quality score; R a α is the surface roughness parameter; h is the removal depth parameter; w is the heat-affected zone width parameter; α is the weighting coefficient; β is the weighting coefficient; γ is the weighting coefficient; α+β+γ=1.

2. The high-radiation underwater non-contact electrical discharge machining method according to claim 1, characterized in that, The pulse power supply signal adopts a multi-stage modulation topology, which includes a front-stage full-bridge inverter circuit and a rear-stage Buck chopper circuit.

3. The high-radiation underwater non-contact electrical discharge machining method according to claim 1, characterized in that, The nanoparticles are insulating ceramic or metal oxide particles, and the aqueous suspension is used to enhance the breakdown strength and insulation properties, with the flow rate adjusted based on the dielectric parameters.

4. The high-radiation underwater non-contact electrical discharge machining method according to claim 1, characterized in that, The feedback control algorithm employs a fuzzy PID control algorithm. The fuzzy PID control algorithm uses the deviation and rate of change of the deviation between the voltage signal, current signal, and medium flow velocity signal as input. The adjustment formula for the PID controller is: In the formula, u(k) is the output feed speed control value at the kth sampling time; e(k) is the deviation between the set gap and the actual gap of the discharge channel; Δe is the deviation change rate; Δt is the sampling period; and e(j) is the deviation value. j is the cumulative index in the integral summation term; This represents the cumulative sum of all deviation values ​​multiplied by the sampling period from the 0th sampling time to the current kth sampling time; K p (e,Δe) is the proportionality constant; K i (e,Δe) are the integral coefficients; K d (e,Δe) are the differential coefficients.

5. A high-radiation underwater non-contact electrical discharge machining device, characterized in that, Based on the method of any one of claims 1 to 4, the apparatus comprises: The processing electrode system, located in a high-radiation underwater environment, includes a main electrode and a secondary electrode for alternating operation, which are switched on and off. The pulse power supply system, connected to the machining electrode system, is used to provide the pulse power signals required for the etching process; An integrated sensing system, including electrical sensors, fluid sensors, optical sensors, and acoustic sensors, is used to acquire physical signals during the processing in real time. A nano-suspension system is used to supply an aqueous suspension containing nanoparticles to the discharge channel and supports bidirectional flow circulation. A feedback controller, connected to an integrated sensing system and a processing electrode system, is used to dynamically adjust the discharge channel gap based on acquired middleware data. The remote monitoring platform is connected to the feedback controller via a high-radiation shielded communication link. It is used to receive middleware data, perform quality assessments, and issue correction instructions.

6. The high-radiation underwater non-contact electrical discharge machining apparatus according to claim 5, characterized in that, The feedback controller has a built-in fuzzy PID control algorithm module for dynamic adjustment of the execution gap.

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