A precision connection detection method and device and a storage medium

Abstract

The present application relates to the technical field of connection detection, and more particularly to a precision connection detection method, device and storage medium, comprising the following steps: step S1, dynamic ballast feedback control; step S2, zero impedance matrix extraction; step S3, signal path impedance active management; step S4, interference field decoupling asynchronous sampling; and step S5, closed-loop impedance skin compensation calculation. The present application realizes comprehensive real-time feedback of physical contact, thermal field and dynamic parameters through dynamic ballast feedback control of pressure contact, environmental thermal field nonlinear compensation of signal transfer plate, active drive circuit phase compensation and asynchronous sampling timing scheduling logic, significantly improves the precision and stability of precision connection detection, and meets the high-precision closed-loop production demand. The present application solves the problems of large nonlinear deviation and poor stability of detection results caused by environmental thermal field temperature drift, parasitic parameter fluctuation and high-voltage field electromagnetic interference in the prior art.

Description

Technical Field

[0001] This invention relates to the field of connection detection technology, and in particular to a precision connection detection method, apparatus and storage medium. Background Technology

[0002] With the rapid development of the electronics manufacturing and new energy industries, the requirements for impedance detection accuracy of precision connectors (such as power battery tabs and microelectronic connectors) are increasing.

[0003] In existing technologies, traditional connection detection methods typically employ a static triggering mode with a fixed ballast force, and impedance compensation is mostly based on a preset linear mathematical model. However, in actual testing, on the one hand, due to drastic changes in ambient temperature and the influence of stray capacitance in cables, the zero-point temperature drift and phase shift generated in the test circuit are difficult to eliminate through simple static zeroing; on the other hand, when the detection system needs to perform AC withstand voltage testing and precision impedance detection simultaneously, electromagnetic interference generated by the high-voltage electric field will severely disrupt the acquisition of impedance signals.

[0004] A significant drawback of existing technologies is that they lack a comprehensive real-time feedback mechanism for physical contact states, environmental thermal field fluctuations, and dynamic parasitic parameters. This results in large nonlinear deviations in detection results under complex operating conditions (such as temperature variations and multiple electric field interferences), and poor test stability, making it difficult to meet the needs of high-precision closed-loop production. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a precision connection detection method, device, and storage medium. Through dynamic ballast feedback control of the pressure contact, environmental thermal field nonlinearity compensation of the signal adapter board, phase compensation of the active drive circuit, and asynchronous sampling timing scheduling logic, comprehensive real-time feedback of physical contact, thermal field, and dynamic parameters is achieved. This significantly improves the accuracy and stability of precision connection detection, meeting the requirements of high-precision closed-loop production. It solves the problems of large nonlinear deviations and poor stability in detection results caused by environmental thermal field temperature drift, parasitic parameter fluctuations, and high-voltage electromagnetic interference in existing technologies.

[0006] To achieve the above objectives, the present invention provides a precision connection detection method, comprising the following steps:

[0007] Step S1: Dynamic ballast feedback control, acquire the pressure signal of the pressure contact applied to the test piece, and determine whether the crimping state has entered the low impedance saturation range based on the contact mechanics model; Step S2: Zero-position impedance matrix extraction, collecting the impedance offset under the environmental thermal field, and using a nonlinear compensation algorithm to compensate for the impedance offset; Step S3: Active management of signal path impedance. The active drive circuit is activated to suppress dynamic AC impedance fluctuations caused by parasitic parameters of the signal path through phase compensation. Step S4: Interference field decoupling asynchronous sampling. In the presence of external field interference, impedance signal acquisition is performed by executing timing scheduling logic based on asynchronous sampling. Step S5: Closed-loop impedance tare compensation calculation. Using the real-time collected pressure characteristics and environmental parameters, dynamic tare compensation processing is performed on the test loop signal to output the precision connection test results.

[0008] On the other hand, a precision connection detection device is also provided, including: The pressure application module is used to apply ballast force to the connector under test through a flexible pressure head with an integrated pressure sensor; The low-impedance positioning module includes a non-metallic base with a guide hole and a dual-ended probe disposed within the guide hole. The difference between the coefficient of thermal expansion of the base material and the coefficient of thermal expansion of the dual-ended probe tube material is within a certain range. Within / K; The signal conversion module includes a signal conversion board with an equipotential shielding layer and a mirror calibration circuit. The signal conversion board has a three-dimensional Faraday cage shielding structure inside, and the reference resistor of the mirror calibration circuit and the contact point of the dual-headed probe are arranged in the same temperature field. A control processing module is used to execute the precision connection detection method according to any one of claims 1 to 8.

[0009] On the other hand, a computer-readable storage medium is also provided, on which a computer program is stored, which, when executed by a processor, implements the steps of the precision connection detection method according to any one of claims 1 to 8.

[0010] The beneficial effects of this invention are as follows: By implementing dynamic ballast feedback control of the pressure contact, nonlinear compensation of the environmental thermal field on the signal adapter board, phase compensation of the active drive circuit, and asynchronous sampling timing scheduling logic, comprehensive real-time feedback of physical contact, thermal field, and dynamic parameters is achieved, significantly improving the accuracy and stability of precision connection detection and meeting the requirements of high-precision closed-loop production. It solves the problems of large nonlinear deviations and poor stability in detection results caused by environmental thermal field temperature drift, parasitic parameter fluctuations, and high-voltage electromagnetic interference in existing technologies. Attached Figure Description

[0011] Figure 1 This is a flowchart illustrating the steps of a precision connection detection method according to the present invention.

[0012] Figure 2 This is a schematic diagram of the structure of a precision connection detection device according to the present invention.

[0013] The reference numerals in the figures include: 1. Pressure application module; 2. Low impedance positioning module; 3. Signal conversion module; 4. Control processing module. Detailed Implementation

[0014] The present invention will now be described in detail with reference to the accompanying drawings.

[0015] like Figure 1 As shown, a precision connection detection method of the present invention includes the following steps: Step S1: Dynamic ballast feedback control acquires the pressure signal applied by the pressure contact to the test piece, and determines whether the crimping state has entered the low impedance saturation range based on the contact mechanics model. By acquiring the pressure signal applied to the test piece through the pressure contact and determining whether the crimping state has entered the low impedance saturation range based on the contact mechanics model, the problem of contact resistance fluctuation caused by unstable crimping force under the traditional static triggering mode is solved, ensuring the standardization of physical contact.

[0016] Step S2: Zero-position impedance matrix extraction. The impedance offset under the ambient thermal field is collected, and the impedance offset is compensated using a nonlinear compensation algorithm. By collecting the impedance offset under the ambient thermal field and compensating for the impedance offset using a nonlinear compensation algorithm, the zero-position temperature drift caused by drastic changes in ambient temperature is accurately eliminated.

[0017] Step S3: Active management of signal path impedance. The active drive circuit is activated, and the dynamic AC impedance fluctuations caused by parasitic parameters of the signal path are suppressed through phase compensation. By activating the active drive circuit and using phase compensation to suppress the dynamic AC impedance fluctuations caused by parasitic parameters of the signal path, the phase shift and signal distortion caused by cable stray capacitance are effectively suppressed.

[0018] Step S4: Interference field decoupling asynchronous sampling. In the presence of external field interference, timing scheduling logic based on asynchronous sampling is executed to acquire impedance signals. By executing timing scheduling logic based on asynchronous sampling to acquire impedance signals in the presence of external field interference, the extraction of weak impedance signals under the background of electromagnetic interference from high-voltage electric fields is realized, solving the pain point of electromagnetic interference disturbing signal acquisition.

[0019] Step S5: Closed-loop impedance tare compensation calculation. Using real-time acquired pressure characteristics and environmental parameters, dynamic tare compensation processing is performed on the test loop signal, outputting the precision connection test results. By using real-time acquired pressure characteristics and environmental parameters to perform dynamic tare compensation processing on the test loop signal, nonlinear deviations in the test results are eliminated, directly outputting the precision connection test results.

[0020] During operation, the pressure contact acts on the test piece and acquires the pressure signal. Based on the contact mechanics model, it determines whether the crimped state has entered the low impedance saturation range to establish physical contact stability. Subsequently, the impedance offset under the ambient thermal field is acquired, and a nonlinear compensation algorithm is used to compensate for the impedance offset to eliminate zero-point temperature drift interference. The active drive circuit is activated, and phase compensation is used to suppress dynamic AC impedance fluctuations caused by parasitic parameters of the signal path to correct the phase offset. In the presence of external field interference, timing scheduling logic based on asynchronous sampling is executed to acquire impedance signals to suppress electromagnetic interference. Finally, using the real-time acquired pressure characteristics and environmental parameters, dynamic tare compensation processing is performed on the test circuit signal to output precise connection detection results to eliminate nonlinear deviations.

[0021] The step of determining the low impedance saturation region in step S1 of this embodiment includes: The pressure load increment and impedance decrease amplitude are collected in real time with a period of 10ms to 50ms, and the rate of change of contact impedance with pressure dR / dF is calculated. When the absolute value of the rate of change dR / dF is less than the preset threshold of 0.05mΩ / N for three consecutive cycles, it is determined that the low impedance saturation contact state has been entered. The actuator is triggered to perform a self-locking action, controlling the press displacement increment within ±2µm.

[0022] By acquiring the pressure load increment and impedance decrease amplitude with a period of 10ms to 50ms and calculating the rate of change of contact impedance with pressure dR / dF, and performing displacement self-locking when the rate of change is less than a preset threshold for three consecutive periods, micron-level locking of the press-fit displacement within ±2µm is achieved, further enhancing the energy stability of the physical interface.

[0023] After determining that a low-impedance saturated contact state has been entered, this embodiment also includes a physical pressure pulse application step: The actuator is controlled to generate controlled micro-vibrations with a frequency of 10Hz to 500Hz and an amplitude of 1µm to 10µm; The duration of the micro-vibration is 50ms to 200ms, and the shear force generated by the micro-vibration is used to destroy the microscopic protrusions of the oxide layer on the contact surface.

[0024] By using shear force to break down the microscopic protrusions of the oxide layer on the contact surface, the effective conductive contact area is increased, thus solving the technical defect of abnormal contact impedance caused by the oxide layer.

[0025] The nonlinear compensation in step S2 of this embodiment includes: The signal adapter board is divided into at least four independent equivalent thermal resistance units, each of which is equipped with a temperature sensing node with a sampling accuracy of 0.1℃; Obtain the real-time temperature T of each temperature sensing node. i The real-time thermal bias vector is calculated by combining the temperature coefficient of resistance α of the conductive material of the adapter plate; The compensation frequency is synchronized with the impedance sampling frequency, controlling the initial impedance consistency error between different sampling apertures to within 0.5mΩ.

[0026] This achieved the effect of controlling the initial impedance consistency error between different hole positions to within 0.5mΩ.

[0027] The logic for suppressing dynamic AC impedance fluctuations in step S3 of this embodiment includes: The phase difference between the signal core and the shielding layer was monitored within a bandwidth range of 100kHz to 2MHz. By controlling the drive signal through feedforward compensation, the phase difference ΔΦ is kept within 0.1°; By keeping the dynamic voltage difference between the core wire and the shielding layer below 10mV, the leakage current generated by the path equivalent stray capacitance is reduced to less than 5% of the original value.

[0028] The equivalent stray capacitance leakage current is reduced to below 5%, which greatly optimizes signal integrity under high-frequency operating conditions.

[0029] Step S4 in this embodiment specifically includes: The phase-locked loop is activated to track the fundamental frequency of the external interference field and generate a sampling clock with a pseudo-random jitter step size of 10ns~1µs; The sampling frequency is set to a non-integer multiple of the external interference field frequency; The cumulative averaging algorithm is used to superimpose signals of at least 16 complete cycles to extract micro-ohm level impedance signals in a high voltage field above 1000V.

[0030] This technology has achieved a signal-to-noise ratio improvement of more than 20dB compared to a single acquisition, ensuring micro-ohm level detection accuracy under high voltage fields above 1000V.

[0031] In step S5 of this embodiment, the dynamic peeling compensation process includes: Establish a three-dimensional coordinate tensor with pressure F, impedance R, and temperature T as variables; The edge computing unit fits and outputs a 64-bit tare compensation vector in real time based on the offset distance of the current physical state point in the tensor space with a cycle period of no more than 5ms. The standard deviation of repeatability of the compensated impedance measurement is less than or equal to 0.02 mΩ.

[0032] By establishing a three-dimensional coordinate tensor of pressure F, impedance R, and temperature T and using edge computing units to perform cyclic fitting within 5ms, extremely high consistency with a measurement repeatability standard deviation σ less than or equal to 0.02mΩ was achieved.

[0033] This embodiment also includes a controlled pulse discharge self-cleaning step: Set the pulse voltage to 10V~50V, the current limit to 10mA~100mA, and the pulse width to 1ms~10ms; After each self-cleaning action, the impedance is re-detected. If the impedance recovery rate does not reach 90% of the initial reference value, the pulse duty cycle is automatically increased for a second cleaning. After three consecutive cleanings fail, a hardware replacement alarm is output.

[0034] By setting a pulse voltage of 10V~50V to perform a self-cleaning action and automatically increasing the duty cycle when the impedance recovery rate does not meet the standard, the online automatic recovery of the test head contact performance is achieved, reducing the frequency of hardware replacement.

[0035] Specifically, before outputting the precise connection detection results in step S5, a multi-source parameter collaborative measurement confidence assessment and graded repair step is also included: Establish a state-space model: extract the pressure change rate dR / dF, phase difference ΔΦ, and repeatability standard deviation σ in real time, and construct a connected state vector V = [dR / dF, ΔΦ, σ; Confidence threshold determination: Set confidence threshold H set When the deviation of the calculated real-time state vector V exceeds the preset fluctuation range, and the repeatability standard deviation σ > 0.02mΩ, it is determined that there is a physical defect or signal interference in the current measurement path, and the current impedance data output is suspended. Execute the hierarchical scheduling repair logic: Level 1 Repair: If the phase difference ΔΦ≤0.1° and the absolute value of the pressure change rate dR / dF is greater than the preset threshold of 0.05mΩ / N, it is determined that the physical contact of the contact surface is poor, and the physical pressure pulse application step is triggered to perform controlled micro-vibration; Secondary repair: If the pressure change rate dR / dF still does not enter the low impedance saturation range after performing the primary repair, the controlled pulse discharge self-cleaning step is triggered. Closed-loop cycle verification: After each repair action is completed, the signal monitoring of steps S1 to S4 is retried until the repeatability standard deviation σ ≤ 0.02mΩ and the pressure change rate dR / dF meets the low impedance saturation contact condition. Then, the dynamic tare compensation process in step S5 is activated and the detection result is output.

[0036] By extracting the pressure change rate dR / dF, phase difference ΔΦ, and repeatability standard deviation σ in real time, a connection status vector is constructed for comprehensive evaluation. This enables comprehensive and coordinated monitoring of the connection status, providing an accurate data foundation for subsequent judgment and repair.

[0037] Set confidence threshold H set When the state vector deviates from the preset range and the repeatability standard deviation σ > 0.02mΩ, the measurement is deemed to have a defect or interference. It can automatically identify and suspend unreliable impedance data outputs to prevent erroneous results.

[0038] If the phase difference ΔΦ ≤ 0.1° and the absolute value of the pressure change rate dR / dF is greater than the preset threshold of 0.05mΩ / N, it is determined to be a case of poor physical contact, triggering a physical pressure pulse to execute controlled micro-vibration. This is a targeted attempt to eliminate measurement problems caused by poor contact surfaces.

[0039] If the pressure change rate dR / dF still does not enter the low impedance saturation range after the first-stage repair, the controlled pulse discharge self-cleaning logic is triggered. When micro-vibration is ineffective, the contact surface is further treated through discharge self-cleaning to restore a stable connection.

[0040] After each repair, signal monitoring is retried until σ ≤ 0.02mΩ and the pressure change rate dR / dF meets the low-impedance saturation contact condition. This forms a repair-verification closed loop, ensuring the reliability of the measurement data before activating dynamic tare compensation processing and outputting the results, ultimately guaranteeing the accuracy and stability of the test results.

[0041] Among them, a multi-order Taylor series expansion algorithm is used to perform nonlinear compensation:

[0042] The impedance offset represents the change in resistance of the signal adapter board as it deviates from its initial reference value under the influence of the real-time environmental thermal field. As an output variable of the compensation system, it is directly used to remove temperature drift noise from the sampled data, thereby controlling the initial impedance consistency error between different sampling apertures to within 0.5mΩ.

[0043] T i Real-time temperature is collected by temperature sensing nodes distributed within at least four independent equivalent thermal resistance units on the signal adapter board. i As an independent variable, it reflects the real-time dynamic thermal field state at the test site and serves as the original input data that triggers the nonlinear compensation logic.

[0044] The reference temperature is the ambient temperature, which is the reference temperature of the signal adapter board under calibrated conditions (usually the initial temperature when the system is zeroed). This forms the center point of the Taylor series expansion, used to calculate the real-time temperature Ti and the reference ambient temperature. The degree of deviation between them.

[0045] ( The value is the reference impedance function value, and the signal adapter board operates at the reference ambient temperature. The initial impedance value at that time. ( As a constant term, ) establishes the zero point location of the impedance compensation matrix.

[0046] Let be the k-th derivative of the impedance function with respect to temperature, and be the k-th sensitivity coefficient of the conductive material of the signal adapter board as the impedance changes with temperature. First derivative. ( The linear temperature coefficient of resistance α corresponds to the linear temperature coefficient of resistance; the second and higher derivatives represent the nonlinear response characteristics of the material under extreme temperature changes or multi-field coupling. By introducing higher derivatives, accurate fitting of nonlinear drift under complex thermal environments is achieved, solving the technical defect that the preset linear mathematical model cannot eliminate nonlinear temperature drift.

[0047] denoted by , where is the standardization coefficient of the Taylor series. n is the expansion order of the formula, which is typically taken as n≥3 in this invention. The expansion order n determines the accuracy depth of the compensation model. Increasing the expansion order n can significantly reduce the residual error caused by the coupling of the high-voltage electric field and the thermal field, ensuring that the standard deviation σ of the repeatability of the compensated impedance measurement is less than or equal to 0.02mΩ.

[0048] This is the power of the change in real-time temperature relative to the reference ambient temperature. This parameter works in conjunction with the k-th derivative to mathematically model the nonlinear deformation or electrical property fluctuation trajectory of a physical entity under thermal field fluctuations.

[0049] Through this compensation logic, the present invention controls the initial impedance consistency error between different sampling apertures to within 0.5mΩ, thus solving the zero-point temperature drift problem caused by drastic changes in ambient temperature.

[0050] The formula for calculating the compensated precision connection test results is as follows:

[0051] in, This is the final high-precision impedance value output after multi-dimensional tare compensation. It represents the "true" contact resistance of the connector under test under standard physical conditions, eliminating the interference from environmental temperature drift, ballast force fluctuations, and path parasitic parameters mentioned in the background art.

[0052] The initial impedance value is obtained directly from the signal acquisition circuit (such as ADC sampling) without processing. This value includes the superposition of contact resistance, test cable impedance, temperature drift noise, pressure deviation noise, and external field interference.

[0053] This mainly refers to the zero-point drift of the signal adapter board and test circuit under the current thermal environment. Subtraction is performed in the formula. This achieves "zero-position tare", correcting the detection benchmark to a unified initial state.

[0054] It is a nonlinear correction function calculated based on the pressure signal F. According to Hertzian contact mechanics and Holm's theory, contact resistance decreases with increasing pressure. Even within the "low impedance saturation range," small pressure fluctuations will still cause impedance changes. It is used to normalize the impedance values ​​under different pressure loads, correct the measurement nonlinearity deviation caused by pressure fluctuations, and ensure the consistency of measurements under ±2µm displacement disturbances.

[0055] Based on real-time temperature The resistance temperature sensitivity correction function. This corrects for the resistivity variation of the measured metal material (such as gold or copper) with temperature. (Correction of equipment temperature drift) is different. It focuses on correcting the thermal effects of the material itself in the test object. By using gain compensation, the test results are ensured to reflect the physical properties of the test piece at the reference temperature under different ambient temperatures.

[0056] like Figure 2 As shown, another aspect provides a precision connection detection device, comprising: Pressure module 1 is used to apply ballast force to the connector under test through a flexible pressure head with an integrated pressure sensor; The low-impedance positioning module 2 includes a non-metallic base with a guide hole and a double-ended probe disposed within the guide hole. The difference between the coefficient of thermal expansion of the base material and the coefficient of thermal expansion of the double-ended probe tube material is within a certain range. Within / K; The signal conversion module 3 includes a signal conversion board with an equipotential shielding layer and a mirror calibration circuit. The signal conversion board has a three-dimensional Faraday cage shielding structure inside, and the reference resistor of the mirror calibration circuit and the contact point of the dual-headed probe are arranged in the same temperature field. The control processing module 4 is used to execute the precision connection detection method described above.

[0057] Through pressure module 1 and low-impedance positioning module 2 (the difference in thermal expansion coefficient is within...) The synergy between the signal transfer module 3 (within K) and the signal transfer module 3 equipped with a three-dimensional Faraday cage shielding structure provides physical-level support against thermal deformation and electromagnetic interference.

[0058] Specifically, the pressure application module 1 can be either Embodiment 1 or Embodiment 2. Example 1: A servo-driven electric actuator combined with a suspended flexible pressure head. The pressure application module 1 includes a drive unit consisting of a high-precision servo motor and a ball screw. The pressure application head is a suspended flexible pressure head with a high-sensitivity thin-film pressure sensor embedded inside. The servo motor receives closed-loop commands from the control processing module 4 and adjusts the pressure load through millisecond-level feed compensation, enabling the pressure application head to achieve flexible buffering at the moment of contact with the workpiece. The pressure sensor provides real-time feedback on the pressure load increment.

[0059] Example 2: Pneumatic proportional valve with bellows compensation scheme. Pressure module 1 uses a precision pneumatic proportional valve to control a miniature cylinder. The cylinder end is connected to a flexible metal bellows structure with constant pressure characteristics. The internal air pressure of the cylinder is adjusted by the pneumatic proportional valve, utilizing the compressibility of the gas to achieve physical damping of force feedback. A displacement sensor is installed on the side of the pressure contact, working in conjunction with air pressure feedback to achieve precise dual control of contact pressure and pressing displacement.

[0060] The low-impedance positioning module 2 can specifically be described in Embodiments 3 and 4. Example 3: A ceramic base combined with a beryllium copper gold-plated double-headed pin design. The non-metallic base of the low-impedance positioning module 2 is made of microcrystalline glass-ceramic (such as machinable ceramic Macor), whose coefficient of thermal expansion is approximately [missing information]. / K. The dual-ended probe is made of beryllium copper tubing with a hard gold plating. The difference in thermal expansion coefficients between the ceramic base and the beryllium copper needle tube is strictly limited to... Within / K, even under conditions of large temperature differences, the fit gap between the guide hole and the probe remains constant, avoiding physical compression deformation caused by thermal expansion and contraction.

[0061] Example 4: A high-performance engineering plastic combined with a stainless steel needle tube solution. The non-metallic base of the low-impedance positioning module 2 is made of carbon fiber reinforced polyetheretherketone (PEEK), and a self-lubricating coating is sprayed onto the inner wall of the guide hole to reduce friction. The dual-ended probe uses an austenitic stainless steel needle tube. Utilizing the extremely high dimensional stability of PEEK material and its thermal expansion characteristics similar to stainless steel, the probe maintains the perpendicularity of its axial movement during frequent reciprocating motion, thereby ensuring the positional accuracy of extremely low impedance sampling.

[0062] The signal conversion module 3 can specifically be from Embodiment 5 and Embodiment 6. Example 5: A six-layer blind-buried via PCB with a three-dimensional isolation and shielding scheme. Signal adapter module 3 adopts a six-layer blind-buried via structure. Inside the signal adapter board, a three-dimensional Faraday cage is formed through a dense via array and inner copper foil enclosure structure, completely surrounding the weak impedance signal path. The mirror calibration loop is arranged on the inner layer adjacent to the main test loop, ensuring that the reference resistor of the mirror calibration loop and the trace of the main test loop are in the same PCB dielectric thermal field.

[0063] Example 6: An equipotential driving layer (Guard) combined with a ceramic-based flexible circuit scheme. The signal transfer module 3 uses a flexible ceramic substrate, with equipotential shielding layers deployed on both sides of the signal lines. The active driving circuit outputs a potential to the shielding layer in real time that is completely consistent with the signal line voltage, making the voltage difference between the signal line and the shielding layer approach zero, thereby eliminating stray capacitance. The mirror calibration loop uses a highly stable manganese-copper resistor mounted on the onboard surface as a reference to correct thermoelectric interference caused by connector contact resistance in real time.

[0064] The control processing module 4 can specifically be from Embodiment 7 and Embodiment 8. Example 7: An FPGA-based embedded solution with a real-time kernel. The core of control processing module 4 is a SoC (such as the Xilinx Zynq series). The FPGA portion is responsible for generating the phase-locked loop clock, feedforward control for phase compensation, and timing scheduling for incoherent asynchronous sampling. The ARM real-time kernel portion is responsible for performing contact mechanics model calculations and dynamic solution of the three-dimensional coordinate tensor. This solution achieves an ultra-fast feedback loop of less than 1ms through hardware acceleration, making it suitable for real-time online detection in high-speed automated production lines.

[0065] Example 8: An industrial host computer combined with an edge computing gateway solution. The control processing module 4 adopts a PC-based edge computing unit, communicating with each sensor module via a high-speed bus (such as EtherCAT or PXIe). The edge computing unit runs a high-order Taylor series algorithm to perform offline modeling and real-time nonlinear compensation on the massive impedance data collected. This solution has powerful data analysis capabilities, can simultaneously handle cross-coupling correction of multiple test channels, and is suitable for comprehensive quality assessment of multi-station precision connectors.

[0066] On the other hand, a computer-readable storage medium is also provided, on which a computer program is stored, which, when executed by a processor, implements the steps of the precision connection detection method described above.

[0067] By implementing the steps of the precision connection detection method described above through a stored computer program, the software-based deployment and high-speed execution of the precision connection detection logic in automated detection equipment are realized.

[0068] The above description is only a preferred embodiment of the present invention. For those skilled in the art, there will be changes in the specific implementation and application scope based on the ideas of the present invention. The content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for detecting precision connections, characterized in that, Includes the following steps: Step S1: Dynamic ballast feedback control, acquire the pressure signal of the pressure contact applied to the test piece, and determine whether the crimping state has entered the low impedance saturation range based on the contact mechanics model; Step S2: Zero-position impedance matrix extraction, collecting the impedance offset under the environmental thermal field, and using a nonlinear compensation algorithm to compensate for the impedance offset; Step S3: Active management of signal path impedance. The active drive circuit is activated to suppress dynamic AC impedance fluctuations caused by parasitic parameters of the signal path through phase compensation. Step S4: Interference field decoupling asynchronous sampling. In the presence of external field interference, impedance signal acquisition is performed by executing timing scheduling logic based on asynchronous sampling. Step S5: Closed-loop impedance tare compensation calculation. Using the real-time collected pressure characteristics and environmental parameters, dynamic tare compensation processing is performed on the test loop signal to output the precision connection test results.

2. The precision connection detection method according to claim 1, characterized in that, The steps for determining the low-impedance saturation region in step S1 include: The pressure load increment and impedance decrease amplitude are collected in real time with a period of 10ms to 50ms, and the rate of change of contact impedance with pressure dR / dF is calculated. When the absolute value of the rate of change dR / dF is less than the preset threshold of 0.05mΩ / N for three consecutive cycles, it is determined that the low impedance saturation contact state has been entered. The actuator is triggered to perform a self-locking action, controlling the press displacement increment within ±2µm.

3. The precision connection detection method according to claim 2, characterized in that, After determining that the low-resistance saturated contact state has been reached, the process also includes applying a physical pressure pulse: The actuator is controlled to generate controlled micro-vibrations with a frequency of 10Hz to 500Hz and an amplitude of 1µm to 10µm; The duration of the micro-vibration is 50ms to 200ms, and the shear force generated by the micro-vibration is used to destroy the microscopic protrusions of the oxide layer on the contact surface.

4. The precision connection detection method according to claim 1, characterized in that, The nonlinear compensation mentioned in step S2 includes: The signal adapter board is divided into at least four independent equivalent thermal resistance units, each of which is equipped with a temperature sensing node with a sampling accuracy of 0.1℃; Obtain the real-time temperature T of each temperature sensing node. i The real-time thermal bias vector is calculated by combining the temperature coefficient of resistance α of the conductive material of the adapter plate; The compensation frequency is synchronized with the impedance sampling frequency, controlling the initial impedance consistency error between different sampling apertures to within 0.5mΩ.

5. The precision connection detection method according to claim 1, characterized in that, The logic for suppressing dynamic AC impedance fluctuations in step S3 includes: The phase difference between the signal core and the shielding layer was monitored within a bandwidth range of 100kHz to 2MHz. By controlling the drive signal through feedforward compensation, the phase difference ΔΦ is kept within 0.1°; By keeping the dynamic voltage difference between the core wire and the shielding layer below 10mV, the leakage current generated by the path equivalent stray capacitance is reduced to less than 5% of the original value.

6. The precision connection detection method according to claim 1, characterized in that, Step S4 specifically includes: The phase-locked loop is activated to track the fundamental frequency of the external interference field and generate a sampling clock with a pseudo-random jitter step size of 10ns~1µs; The sampling frequency is set to a non-integer multiple of the external interference field frequency; The cumulative averaging algorithm is used to superimpose signals of at least 16 complete cycles to extract micro-ohm level impedance signals in a high voltage field above 1000V.

7. The precision connection detection method according to claim 1, characterized in that, The dynamic peeling compensation process in step S5 includes: Establish a three-dimensional coordinate tensor with pressure F, impedance R, and temperature T as variables; The edge computing unit fits and outputs a 64-bit tare compensation vector in real time based on the offset distance of the current physical state point in the tensor space with a cycle period of no more than 5ms. The standard deviation of repeatability of the compensated impedance measurement is less than or equal to 0.02 mΩ.

8. The precision connection detection method according to claim 1, characterized in that, It also includes a controlled pulse discharge self-cleaning step: Set the pulse voltage to 10V~50V, the current limit to 10mA~100mA, and the pulse width to 1ms~10ms; After each self-cleaning action, the impedance is re-detected. If the impedance recovery rate does not reach 90% of the initial reference value, the pulse duty cycle is automatically increased for a second cleaning. After three consecutive cleanings fail, a hardware replacement alarm is output.

9. A precision connection detection device, characterized in that, include: The pressure module (1) is used to apply a pressure force to the connector under test through a flexible pressure head with an integrated pressure sensor; The low-impedance positioning module (2) includes a non-metallic base with a guide hole and a double-ended probe disposed in the guide hole. The difference between the thermal expansion coefficient of the base material and the thermal expansion coefficient of the double-ended probe tube material is within a certain range. Within / K; The signal conversion module (3) includes a signal conversion board with an equipotential shielding layer and a mirror calibration circuit. The signal conversion board has a three-dimensional Faraday cage shielding structure inside, and the reference resistor of the mirror calibration circuit and the contact of the dual-head probe are arranged in the same temperature field. The control processing module (4) is used to execute the precision connection detection method according to any one of claims 1 to 8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the program implements the steps of the precision connection detection method according to any one of claims 1 to 8.

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