Co-assembly method of copper plate fusion module and nylon rivet

Abstract

This invention discloses a method for the collaborative assembly of a copper plate fusion module and nylon rivets, relating to the fields of servo precision press-fitting and adaptive control technology. Addressing the defect of fluctuating physical states of polymer materials due to temperature and humidity changes, this method simultaneously collects press-fitting force and displacement data. In the first stage of rivet radial unfolding, the mechanical work is calculated through curve integration to obtain the material state coefficient. Based on this coefficient, the target preload stiffness for the second stage is dynamically reconstructed. Finally, the assembly stiffness is calculated in real time and closed-loop displacement compensation is performed to converge it to the target range. This invention achieves cross-stage adaptive reconstruction of control parameters, effectively avoiding assembly damage and preload attenuation caused by dry-cold brittle fracture or damp-heat creep, significantly improving the safety and reliability of electrical connections.

Description

Technical Field

[0001] This invention relates to the field of servo precision press-fitting and adaptive control technology, and more specifically, to a method for the coordinated assembly of a copper plate fusion module and nylon rivets. Background Technology

[0002] In the power distribution unit of new energy vehicles and energy storage systems, nylon rivets are usually used to fasten the copper plate fusion module to the insulating base. At present, this type of automated assembly mostly uses servo presses and performs process control based on preset fixed displacement or force threshold templates.

[0003] However, nylon and other polymer materials are significantly sensitive to temperature and humidity. In actual industrial settings, the physical and mechanical properties of the materials are easily subject to dynamic fluctuations due to the influence of ambient temperature and humidity and batch storage time. For example, in low-temperature or dry environments, nylon has high crystallinity and exhibits a hard and brittle state; in high-temperature or high-humidity environments, the yield strength of the material decreases and it exhibits a soft and tough state.

[0004] Existing fixed-parameter press-fitting processes cannot adapt to the objective differences in the aforementioned material states in real time. When the material is in a hard and brittle state, press-fitting with fixed parameters can easily lead to brittle fracture or base cracking when the rivet is radially expanded. When the material is in a soft and ductile state, the initial axial interference at the assembly interface is often insufficient. It should be noted that the copper plate fuse module, as a high-power electrical protection node, is accompanied by extremely high transient currents and continuous Joule heating during service. This intense thermal stress directly conducted by the copper plate busbar will greatly accelerate the relaxation of the polymer chain segments of the nylon rivet that is tightly attached to it, resulting in the attenuation of residual preload, loosening of the contact surface, and a surge in resistance.

[0005] To address the above problems, this invention proposes a solution. Summary of the Invention

[0006] To overcome the aforementioned deficiencies of the prior art, embodiments of the present invention provide a method for the collaborative assembly of a copper plate fusing module and nylon rivets. This method addresses the problems mentioned in the background art by establishing an adaptive closed-loop compensation mechanism based on real-time material state assessment and cross-stage parameter coupling using in-situ work integrals.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A method for co-assembling a copper plate fusion module and nylon rivets includes the following steps: a servo press-fitting mechanism drives the nylon rivets to move towards the mounting hole of the copper plate fusion module. During the press-fitting process, press-fitting force data and displacement data are collected simultaneously, and a force-displacement curve is constructed. Based on the force-displacement curve, the displacement interval corresponding to the radial unfolding stage of the nylon rivets is identified. Within the displacement interval, the force-displacement curve is integrated to obtain the mechanical work done in the first stage, and the material state coefficient is calculated based on the mechanical work done. Based on the material state coefficient, the target pre-tightening stiffness and allowable compensation range of the second stage of press-fitting are dynamically determined to achieve cross-stage control parameter reconstruction. During the second stage of press-fitting, the assembly stiffness is calculated in real time, and the displacement compensation amount is calculated based on the deviation between the real-time assembly stiffness and the target pre-tightening stiffness using an adaptive compensation formula for stiffness deviation based on material state coupling. The servo press-fitting mechanism is controlled to perform displacement compensation, so that the actual assembly stiffness converges to the target pre-tightening stiffness range, thereby completing the co-assembly of the copper plate fusion module and the nylon rivets.

[0009] In a preferred embodiment, the amount of mechanical work done in the first stage is calculated according to the following formula: ;in: Indicates the starting displacement point of the first stage; This indicates the end point of the first stage displacement; This represents the pressing force function corresponding to the displacement.

[0010] In a preferred embodiment, the material state coefficient is calculated according to the following formula: ;in: This represents the pre-stored standard theoretical work done.

[0011] In a preferred embodiment, the target preload stiffness is determined according to the following relationship: ;in: Indicates the reference preload stiffness; This represents the adjustment function that varies with the material's state coefficient.

[0012] In a preferred embodiment, during the press-fitting process, the position where the disc-shaped spring and the copper plate are in complete contact is determined by identifying the trend of the first derivative of the force-displacement curve and combining it with the extreme value of the abrupt change of the second derivative as the true zero point of assembly, so as to eliminate the influence of the thickness tolerance of the copper plate and the base.

[0013] In a preferred embodiment, the displacement compensation amount is calculated according to the following formula: ;in: Represents the system gain constant; This represents a compensation weighting function that is positively correlated with the material state coefficient; This indicates the real-time assembly stiffness.

[0014] In a preferred embodiment, the copper plate fusion module includes an electrical contact area and a fusion slit with a reduced cross-sectional area, and the end face of the nylon rivet has a disc-shaped spring. In step S4, the actual assembly stiffness is converged to the target preload stiffness range, which aims to make the disc-shaped spring form a constant normal pressure on the surface of the electrical contact area to maintain the target contact resistance, while limiting the maximum pressing force applied to the copper plate fusion module to below the mechanical yield stress threshold of the fusion slit.

[0015] In a preferred embodiment, the pressing action is stopped when the real-time assembly stiffness reaches the target preload stiffness or the compensation displacement reaches the maximum allowable compensation displacement.

[0016] In a preferred embodiment, after assembly is completed, the quality is judged based on the feature vector composed of the mechanical work done in the first stage, the material state coefficient, the real-time assembly stiffness, and the displacement compensation, and an assembly qualified or abnormal signal is output.

[0017] An intelligent assembly system includes: a servo press-fitting actuator for driving nylon rivets to perform press-fitting and displacement compensation actions; a force sensor disposed between the press head and the servo press-fitting actuator for real-time acquisition of press-fitting force data; a displacement sensor for real-time acquisition of press-fitting displacement data; and a control system communicatively connected to the servo press-fitting actuator, the force sensor, and the displacement sensor for synchronously acquiring force and displacement data, calculating mechanical work and material state coefficients, reconstructing the target preload stiffness, and outputting control commands to drive the servo press-fitting actuator to perform displacement compensation.

[0018] The technical effects and advantages of the co-assembly method of the copper plate fusion module and nylon rivets of this invention are as follows:

[0019] This invention introduces in-situ work integral calculation in the first stage of press fitting. By performing real-time integral processing on the force and displacement curves, the mechanical energy consumption during the press fitting process is used as a comprehensive characterization parameter reflecting the moisture content, temperature and aging state of nylon materials. This enables online identification of the physical state of polymer materials. Compared with traditional methods that rely on fixed process parameters or environmental adjustments, this invention can significantly reduce the impact of material state fluctuations on assembly quality and improve process adaptability and stability.

[0020] This invention constructs a cross-stage parameter coupling and adaptive displacement compensation mechanism, which feeds forward the material state parameters obtained in the first stage to the assembly control process in the second stage. When the material is in a soft and tough state, the target pre-tightening stiffness is automatically increased and the displacement compensation amount is increased. Essentially, this is to resist the continuous high thermal load unique to copper plates, so as to overdraw in advance and offset the thermal creep pre-tightening force decay caused by the high current Joule heat conduction of copper plates. When the material is in a hard and brittle state, the press-fitting stiffness requirement is adaptively reduced, thereby effectively avoiding the risk of damage to the insulating base.

[0021] This invention uses the second derivative characteristic analysis of force and displacement curves to pinpoint the true zero point of contact between the disc-shaped spring and the copper plate, ensuring that the disc-shaped spring provides a constant electrical contact normal pressure. This guarantees extremely low contact resistance at the micro-ohm level and avoids stress damage or plating peeling in the narrow area of ​​the copper plate due to overvoltage. Furthermore, by combining the work done, material state coefficient, actual stiffness, and compensation displacement to construct a multi-dimensional feature matrix, it can distinguish between material abnormalities and dimensional tolerance abnormalities after assembly, enabling accurate identification of assembly defects and traceability of quality data, thereby improving assembly accuracy and product reliability. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of the intelligent assembly system for the collaborative assembly method of the copper plate fusing module and nylon rivets of the present invention.

[0023] Figure 2 This is a functional block diagram of the control system of the copper plate fusing module and nylon rivet co-assembly method of the present invention.

[0024] Figure 3 This is a flowchart illustrating the method for co-assembling the copper plate fusing module and nylon rivets according to the present invention.

[0025] Figure 4 This is a schematic diagram of the force and displacement characteristic curves and cross-order characteristic identification during the press-fitting process of the present invention.

[0026] Figure 5 This is a schematic diagram illustrating the evolution of the physical state of the cross-stage assembly according to the present invention.

[0027] Figure 6 This is a schematic diagram illustrating the mapping relationship between the material state coefficient and the target preload stiffness of the present invention. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0029] Example 1, as Figure 1 As shown, this embodiment provides a control system for performing the above-mentioned copper plate fusion module and nylon rivet collaborative assembly method. The system runs on an industrial control computer or PLC with low-level data processing capabilities. The system also includes a servo driver, a press-fitting actuator, a force sensor mounting base, and a displacement sensor mounting assembly. The control system forms a closed-loop control connection with the actuator and sensor through a fieldbus or industrial Ethernet. The force sensor is disposed between the press head and the servo press-fitting actuator.

[0030] Furthermore, such as Figure 2As shown, at the software logic level, the control system architecture of this invention mainly includes the following four core modules:

[0031] The multi-source high-frequency sensing and noise reduction module is used to synchronously acquire force and displacement data in the pressing process at the microsecond level based on a unified hardware clock. It uses moving average filtering, low-pass filtering or equivalent digital filtering algorithms to process the acquired signals to filter out high-frequency resonance noise generated during servo drive operation and mechanical contact transients, thereby constructing a high-fidelity continuous force and displacement mapping curve.

[0032] The in-situ work integral and material state assessment module is used to perform definite integral calculation on the force and displacement curves in the first stage of press fitting, namely the radial unfolding stage of nylon rivets, to obtain the real-time mechanical work. The in-situ work refers to the instantaneous mechanical energy consumption calculated based on the force and displacement data collected in real time during the assembly process. The mechanical work can reflect the real physical characteristics of nylon rivet material under the combined effects of current ambient temperature, humidity and material aging state, and output the feedforward physical state coefficient characterizing the material state accordingly.

[0033] The cross-stage parameter coupling calculation engine is used to receive the feedforward physical state coefficients output by the material state assessment module and convert them into dynamic control target parameters to guide the second stage of press fitting. The cross-stage parameter coupling refers to the mapping relationship construction process between the physical characteristic parameters of the first stage of press fitting and the control target parameters of the second stage, thereby realizing the parameter association and control strategy reconstruction between different assembly stages.

[0034] The dynamic displacement compensation closed-loop execution module is used to receive the dynamic pre-tightening target issued by the computing engine, determine the closed-loop displacement compensation amount by calculating the stiffness of the assembly end structure and its rate of change in real time, and drive the servo press-fitting actuator to perform micron-level displacement adaptive compensation, so that the actual assembly stiffness converges to the target control range, and outputs the product qualification or non-qualification judgment result.

[0035] Example 2, as Figure 3 As shown, based on the system architecture described in Embodiment 1, this embodiment elaborates in detail the specific execution steps of the method for co-assembling the copper plate fusing module and the nylon rivet:

[0036] Step S1 is used to establish a basic physical characteristic data model of the press-fitting process. The nylon rivet is driven into the mounting hole by the servo press head, and the press-fitting force and displacement data are acquired synchronously by high-frequency sampling. After filtering, a continuous force and displacement function is formed, and its first and second derivative characteristic quantities are calculated. This forms the basic data source required for subsequent material state identification, contact characteristic judgment and compensation control.

[0037] Step S2 is used to extract key mechanical features and calculate material state parameters during the radial unfolding stage of nylon rivets. The end point of the first stage is determined by the local maximum value or the zero point of the derivative of the force and displacement curve. The in-situ work integral calculation is performed on the force and displacement curve in this interval to obtain the total work done by deformation in the first stage. The material state coefficient is calculated based on the pre-stored standard work, thereby realizing the real-time quantitative characterization of the current temperature, humidity and mechanical properties of nylon materials, providing a basis for the adaptive reconstruction of subsequent press fitting parameters.

[0038] Step S3 is used to adaptively reconstruct the assembly control parameters of the second stage based on the material state coefficient. By establishing the mapping relationship between the material state coefficient and the target pre-tightening stiffness and the maximum allowable compensation displacement, the press-fit target parameters are dynamically determined, so that the assembly process can automatically adjust the press-fit strategy according to the difference between the soft and tough state or the hard and brittle state of nylon material, thereby realizing cross-stage parameter coupling control and improving assembly reliability.

[0039] Step S4 is used to accurately determine the assembly reference position and close-loop convergence control of the target pre-tightening stiffness during the second stage of press fitting. By identifying the derivative characteristics of the force and displacement curves, the true zero point of the assembly is locked, and on this basis, the assembly stiffness deviation is calculated in real time and adaptive displacement compensation is performed so that the actual assembly state gradually approaches the target pre-tightening stiffness, thereby completing high-precision assembly control.

[0040] Step S5 is used to comprehensively analyze the multi-dimensional characteristic parameters formed during the pressing process after a single assembly cycle, so as to realize assembly quality judgment, anomaly type identification and product data storage. By distinguishing the different sources of material state anomalies and structural dimension anomalies, intelligent judgment and defect isolation of assembly results are completed, and data support is provided for subsequent product life cycle traceability.

[0041] Furthermore, the specific calculation steps include the following:

[0042] Step S1: The servo pressure head drives the nylon rivet to press downwards at a set initial speed into the mounting hole of the copper plate fusing module assembly. The system synchronously extracts the pressing force according to a preset high-frequency sampling rate. With displacement For the data pairs, the control system uses a moving average filter to construct a continuous force and displacement function. The function is then subjected to real-time first and second derivative operations to provide baseline data for subsequent feature extraction.

[0043] Step S2: As Figure 4 , Figure 5 As shown, in the range where the press-fit displacement reaches the point where the metal mandrel expands the nylon sleeve ,in This is the starting displacement point for the first stage. The first stage ends at the displacement point, within the interval. This is the first stage. In the first stage, the system extracts the first stage mechanical peak value. Simultaneously, the in-situ work integral algorithm is triggered. In-situ work refers to the instantaneous mechanical energy consumption calculated based on real-time force and displacement data during the assembly process. The controller performs definite integral on the force and displacement curves within this interval to calculate the total work done by deformation in the first stage. :

[0044] ;

[0045] Integral area It accurately reflects the actual mechanical energy consumed by the nylon rivet to resist radial expansion, and is a mirror image of the rivet's current comprehensive physical state of temperature and humidity;

[0046] The system retrieves the pre-stored standard theoretical work quantity. Calculate the current material state coefficient :

[0047] ;

[0048] like The nylon part is determined to be in a hard and brittle state due to extreme dryness or low temperature; if The nylon component was determined to be in a soft and pliable state under high humidity or high temperature.

[0049] The standard theoretical work done The data was obtained through multiple batches of calibration experiments under standard environmental conditions and stored in the control system database.

[0050] Step S3: As Figure 6 As shown, the system uses the data obtained in step S2. Dynamically reconstruct the target preload stiffness in the second stage and maximum allowable compensation displacement :

[0051] ;

[0052] in: Indicates the reference preload stiffness; This represents the adjustment function indicating a positive correlation.

[0053] When the system determines that the condition is a soft and flexible state prone to thermal creep relaxation, it automatically increases the target preload stiffness. To increase the initial interference to pre-draw the creep margin, thereby resisting the continuous high temperature thermal load when the copper plate fuse module is running at high current; if it is determined to be in a hard and brittle state, the stiffness requirement is appropriately reduced to prevent the insulation base from being crushed.

[0054] As a preferred embodiment of the present invention, the adjustment function and compensation weight function Piecewise linear mapping or polynomial fitting can be used. Specifically: for the adjustment function... ,when When the fluctuation range is within the normal range, linear fine-tuning is used: ,in This is the sensitivity coefficient, and its value range is... ;when At that time, exponential enhancement compensation is used: ,in To enhance the coefficient and reserve a larger preload to resist extreme creep risks, the control system can quickly output accurate stiffness target values ​​within millisecond-level calculation cycles by defining the specific mathematical mapping rules mentioned above.

[0055] Step S4: As pressing continues, the disc-shaped spring on the rivet end face contacts the copper plate, locking the true zero point through the following steps: The system captures the rising segment of the first derivative of the force-displacement curve, and combines it with the second derivative. The abrupt extreme point is when the disc-shaped spring is in complete contact with the copper plate. The structural stiffness changes abruptly, thus forming an obvious extreme point in the second derivative of the force-displacement curve. This accurately locks the true zero-point displacement of the disc-shaped spring when it is completely in contact with the surface of the copper plate, thereby eliminating the interference of the thickness tolerance of the copper plate and the base.

[0056] Because the copper plate fuse module has a sensitive fuse narrow area with abrupt changes in cross-sectional area, and its surface is usually plated with an anti-oxidation conductive layer, it is extremely sensitive to assembly tolerances and end face clamping force. The underlying purpose of this invention to accurately lock the true zero point and perform stiffness closed-loop compensation is to ensure that the disc spring provides a constant electrical contact normal pressure, which not only ensures extremely low contact resistance, but also avoids stress microcracks or plating peeling in the copper plate fuse narrow area caused by overvoltage, thereby ensuring the stability of the ampere-second characteristics of the fuse module.

[0057] The closed-loop execution process of dynamic displacement compensation is as follows:

[0058] The system calculates the actual stiffness of the assembly end in real time. Because force and displacement sensors in industrial environments exhibit high-frequency mechanical vibration noise, this invention employs a difference approximation or least squares fitting algorithm based on a sliding data window to obtain the actual stiffness in real time in order to ensure the smoothness of the calculated stiffness and the stability of the closed-loop control. The specific calculation process is as follows:

[0059] After the second stage of press-fitting crosses the true zero point, the control system establishes a dynamically updated sliding data window in memory. This window contains N consecutively sampled data points from the past. The system extracts the incremental quotients at both ends of this window in real time to calculate the current transient actual stiffness. :

[0060] ;

[0061] in: and These represent the pressing force and displacement at the latest sampling moment, respectively; and These represent the pressing force and displacement at the start of the sliding data window, respectively;

[0062] By continuously updating the window through an extremely high scanning cycle controlled by the system, the system can continuously acquire the smooth actual assembly stiffness after burr filtering. ;like If this occurs, an adaptive compensation mechanism is triggered, and the dynamic compensation amount is calculated based on the adaptive compensation formula for stiffness deviation based on material state coupling. :

[0063] ;

[0064] in: Represents the system gain constant; This represents a compensation weighting function that is positively correlated with the material state coefficient;

[0065] The controller drives the servo press to continue its gradual downward movement until the real-time stiffness reaches the target. or reach the maximum allowable compensation displacement Then stop the action;

[0066] Furthermore, to ensure the safe operation of the pressing equipment in the industrial field, the intelligent control system of this invention also incorporates a boundary safety protection mechanism. During the closed-loop execution of dynamic displacement compensation in step S4, the system continuously monitors the absolute output torque and displacement change rate of the servo pressing actuator. If the compensation amount is calculated... If, due to sudden noise from the sensor, the value exceeds the preset safe mechanical limit, or if the actual pressing force suddenly increases and exceeds the material's yield strength warning line during the compensation and lowering process, the system will immediately cut off the compensation command and trigger a hardware-level emergency stop response. This mechanism effectively prevents accidents such as insulation base explosion or press head collision caused by algorithm calculation exceeding limits or sensor failure, ensuring the safety of the production line's core assets.

[0067] Step S5: After a single assembly cycle is completed, the system uses the feature vector... Perform comprehensive quality assessment and isolation:

[0068] Qualified output: All characteristic parameters and stiffness compensation results are within the dynamic coupling tolerance. The assembly success signal is output, and the characteristic vector is stored in the database for life cycle traceability.

[0069] Material abnormality isolation: If lead to If the boundary is seriously exceeded, a warning will be issued directly for materials that are too cold and brittle or too soft, and the machine will be stopped to intercept the batch of unqualified rivet consumables.

[0070] Dimensional tolerance isolation: if actual stiffness Despite server system compensation, the maximum allowed travel was exhausted. If the target stiffness is not yet achieved, an alarm will be triggered if the negative tolerance of the output copper plate exceeds the limit or if the disc spring is missing.

[0071] Example 3: In a specific application scenario, nylon rivets are assembled under ambient temperature of 30°C and relative humidity of 75%. The system identifies the displacement range during the first stage of press-fitting. The deformation ranges from 0.9 mm to 2.0 mm. The work done by the first-stage deformation is calculated by integrating force and displacement. It is 0.41J;

[0072] Furthermore, the system retrieves the standard theoretical work done by the corresponding rivet model from the database. The value is 0.34 J, from which the material state coefficient is calculated. The system determined that this batch of nylon rivets was in a soft and flexible state;

[0073] Based on the aforementioned material state coefficients, the system dynamically calculates the target preload stiffness for the second stage, setting a reference stiffness. The target stiffness is 120 N / mm, calculated using an adjustment function. It is 142 N / mm;

[0074] During the subsequent press-fitting process, the system calculates the actual assembly stiffness in real time. The value is 118 N / mm, which is lower than the target stiffness. Therefore, the compensation control mechanism is triggered, and the compensation displacement is calculated. With a displacement of 0.16 mm, after the servo press-fitting mechanism performs micro-displacement compensation, the actual assembly stiffness reaches the target range, the system determines that the assembly is qualified and outputs a completion signal; this example shows that the present invention can automatically adjust the assembly strategy according to the differences in material state, effectively improve the consistency of assembly stiffness and reduce the assembly defect rate.

[0075] This invention establishes a physical mapping relationship between the mechanical energy characteristics of the assembly process and the material state, thereby enabling adaptive reconstruction of assembly control parameters and breaking through the technical bottleneck of traditional press fitting that relies on fixed process parameters.

[0076] Furthermore, although the embodiments of the present invention are mainly described in detail using the assembly of nylon rivets and copper plate fusion modules as an example, those skilled in the art should understand that the material state assessment and cross-order stiffness reconstruction method based on in-situ work integral proposed in this invention is also applicable to other polymer fasteners with similar temperature and humidity sensitivity or viscoelastic characteristics, such as precision assembly scenarios of engineering plastic riveting parts such as polybutylene terephthalate, polyphenylene sulfide, or polycarbonate.

[0077] It should be noted that, for the sake of brevity, the foregoing method embodiments are described as a series of actions, but this does not mean that the application limits the order of the steps. Based on the ideas of this application, some steps can be executed in different orders or in parallel without affecting the functional implementation. Secondly, those skilled in the art should also understand that the specific embodiments described in the specification are preferred embodiments of the technical solutions of this application, and not limitations on the scope of protection of this application. All equivalent improvements or substitutions made within the spirit and principles of this application should be covered within the scope of protection of this application.

[0078] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for co-assembling a copper plate fusion module and nylon rivets, characterized in that, Includes the following steps: The servo press-fitting mechanism drives the nylon rivet to move toward the mounting hole of the copper plate fusion module. During the press-fitting process, the press-fitting force data and displacement data are collected simultaneously, and the force-displacement curve is constructed. The displacement interval corresponding to the radial unfolding stage of the nylon rivet is identified based on the force-displacement curve. Within the displacement interval, the mechanical work done in the first stage is calculated by integrating the force-displacement curve. The mechanical work done in the first stage is calculated according to the following formula: ； in: Indicates the starting displacement point of the first stage; This indicates the end point of the first stage displacement; The pressing force function corresponding to the displacement is represented; and the material state coefficient is calculated based on the mechanical work done in the first stage, the material state coefficient being calculated according to the following formula: ； in: This represents the pre-stored standard theoretical work done; The target preload stiffness and allowable compensation range for the second stage of press fitting are dynamically determined based on the material state coefficient, thereby achieving cross-stage control parameter reconstruction; the target preload stiffness is determined according to the following relationship: ； in: Indicates the reference preload stiffness; The adjustment function represents the variation of the material's state coefficient; During the second stage of press fitting, the real-time assembly stiffness is calculated, and the displacement compensation amount is calculated based on the deviation between the real-time assembly stiffness and the target preload stiffness using an adaptive compensation formula for stiffness deviation based on material state coupling; the displacement compensation amount is calculated according to the following formula: ； in: Represents the system gain constant; This represents a compensation weighting function that is positively correlated with the material state coefficient; Indicates real-time assembly stiffness; The servo press-fitting mechanism is controlled to perform displacement compensation, so that the real-time assembly stiffness converges to the target pre-tightening stiffness range, thereby completing the coordinated assembly of the copper plate fusion module and the nylon rivet.

2. The method for co-assembling the copper plate fusing module and nylon rivets according to claim 1, characterized in that, During the press-fitting process, the position where the disc-shaped spring and the copper plate are in complete contact is determined by identifying the trend of the first derivative of the force and displacement curve and combining the extreme value of the second derivative mutation, so as to eliminate the influence of the thickness tolerance of the copper plate and the base.

3. The method for co-assembling the copper plate fusing module and nylon rivets according to claim 1, characterized in that, The copper plate fusion module includes an electrical contact area and a fusion-breaking zone with a reduced cross-sectional area. The end face of the nylon rivet has a disc-shaped spring. The purpose of converging the real-time assembly stiffness to the target preload stiffness range is to enable the disc-shaped spring to form a constant normal pressure on the surface of the electrical contact area to maintain the target contact resistance, while limiting the maximum pressing force applied to the copper plate fusion module to below the mechanical yield stress threshold of the fusion-breaking zone.

4. The method for co-assembling the copper plate fusing module and nylon rivets according to claim 1, characterized in that, When the real-time assembly stiffness reaches the target preload stiffness or the displacement compensation reaches the maximum allowable compensation displacement, the pressing action is stopped.

5. The method for co-assembling the copper plate fusing module and nylon rivets according to claim 1, characterized in that, After assembly, the quality is judged based on the characteristic vector formed by the mechanical work done in the first stage, the material state coefficient, the real-time assembly stiffness, and the displacement compensation, and an assembly qualified or abnormal signal is output.

6. An intelligent assembly system for performing the collaborative assembly method of copper plate fusing module and nylon rivets as described in any one of claims 1 to 5, characterized in that, The system includes: Servo press-fitting actuator, used to drive nylon rivets to perform press-fitting and displacement compensation actions; A force sensor is installed between the pressure head and the servo pressing actuator to acquire pressing force data in real time; Displacement sensor, used to acquire press-fit displacement data in real time; The control system is communicatively connected to the servo press-fitting actuator, force sensor, and displacement sensor. It is used to synchronously collect force and displacement data, calculate the mechanical work done in the first stage and the material state coefficient, reconstruct the target pre-tightening stiffness, and output control commands to drive the servo press-fitting actuator to perform displacement compensation.

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