Multi-rivet synchronous riveting control method and related device

Abstract

The invention discloses a multi-rivet synchronous riveting control method and a related device. The method comprises the steps that the interaction strength between rivets is calculated according to rivet position parameters and material parameters, and functional grouping is conducted; stress wave propagation delay time is calculated according to the spatial distribution of the rivet cooperation pressing rivet set, and a time sequence cascade control instruction is generated; performing cascade press riveting based on multiple groups of cooperative control sequences, monitoring a stress wave superposition effect in real time, predicting a stress concentration position, and performing press riveting parameter dynamic modulation on a prediction area; monitoring the electrochemical potential difference change of the different material interface according to the stress wave cooperative control state, predicting the electrochemical instability risk, and carrying out interface pressure self-adaptive adjustment; and performing global residual stress optimization adjustment according to the stress wave cooperative control state and the interface electrochemical equilibrium state. According to the scheme, the problems of residual stress concentration and electrochemical instability caused by instantaneous coupling can be effectively solved, and the quality consistency and long-term reliability of multi-rivet synchronous riveting are remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of multi-rivet synchronous riveting control, and particularly relates to a multi-rivet synchronous riveting control method and related device. BACKGROUND

[0002] Multi-rivet synchronous riveting refers to a connection process in which multiple servo riveting guns simultaneously press multiple rivets into preset hole positions within one assembly beat. This process arranges matrix-type riveting units on a gantry, robot, or flexible fixture, and achieves the synchronous pressing of dozens or even hundreds of rivets through a real-time control bus, which can significantly compress the assembly cycle and reduce cumulative positioning errors. Compared with traditional single-point sequential riveting, multi-rivet synchronous riveting has obvious advantages in efficiency and precision in the assembly of large fuselage sections, composite skin, and dissimilar material structures, and has become a key technology in high-end manufacturing fields such as aerospace and new energy vehicles.

[0003] However, the existing technology faces a fundamental technical bottleneck when implementing multi-rivet synchronous riveting: each rivet forming instant will excite high-frequency stress waves in the surrounding plate. Due to the 50-200 microsecond phase difference between servo actuators and the material dispersion difference of each rivet point, these stress waves form a complex dynamic wavefront network inside the plate. The uncertainty of wavefront meeting positions causes transient warping and residual stress accumulation on the plate surface. Meanwhile, in dissimilar material connection scenarios, the lubricating liquid, cooling liquid, and other substances squeezed out during the synchronous pressing process form a continuous electrolyte liquid film between multiple riveting points, causing the originally isolated riveting points to influence each other through electrochemical means, forming a transient electrochemical coupling effect. This mutual amplification of transient mechanical coupling and transient electrochemical coupling causes unpredictable geometric mismatch and early corrosion initiation of the workpiece after the fixture constraint is released. The existing process cannot real-time perceive and control such coupling effects during the riveting process by simply increasing the fixture stiffness and adding offline straightening, making it difficult to fundamentally solve the problem. SUMMARY

[0004] The main purpose of the present application is to solve the technical problem that the existing multi-rivet synchronous riveting technology cannot real-time perceive, predict, and control the uneven residual stress distribution and electrochemical instability risk caused by the mutual amplification of transient mechanical coupling and electrochemical coupling.

[0005] The first aspect of the present application provides a multi-rivet synchronous riveting control method, which comprises: calculating the interaction strength between rivets according to rivet position parameters and material parameters, functionally grouping multiple rivets to obtain a rivet cooperative riveting group; calculating stress wave propagation delay time according to the spatial distribution of the rivet cooperative riveting group, generating time sequence cascade control instructions to obtain multiple cooperative control sequences; performing cascade riveting based on the multiple sets of cooperative control sequences, monitoring stress wave superposition effects in real time and predicting stress concentration positions, dynamically adjusting riveting parameters for predicted stress concentration areas, and obtaining a stress wave cooperative control state; monitoring changes in electrochemical potential differences at the dissimilar material interfaces according to the stress wave cooperative control state, predicting electrochemical instability risks and performing interface pressure self-adaptive adjustment on high-risk areas, and obtaining an interface electrochemical equilibrium state; performing global residual stress optimization adjustment on each rivet cooperative riveting group according to the stress wave cooperative control state and the interface electrochemical equilibrium state, and obtaining a system balance control state.

[0006] Preferably, the rivet interaction strength is calculated according to rivet position parameters and material parameters, and multiple rivets are functionally grouped to obtain a rivet cooperative riveting group, including: obtaining spatial coordinates and connection direction angles of each rivet position, and calculating mechanical stress propagation strength and electrochemical coupling strength between each rivet according to the spatial coordinates, connection direction angles, and electrochemical activity differences of dissimilar material interfaces and workpiece material thickness distribution parameters; calculating the comprehensive interaction strength between each rivet pair by a weighted fusion algorithm according to the mechanical stress propagation strength and the electrochemical coupling strength, identifying the dominant path of stress wave propagation and the high-risk channel of electrochemical connection, and obtaining a rivet interaction strength matrix; constructing an inhibition-cooperation relationship network between rivets based on the rivet interaction strength matrix, identifying mutually inhibited rivet sets and mutually cooperative rivet sets, differentially assigning weights to rivets according to inhibition-cooperation relationship strength, and obtaining a weighted grouping strategy; assigning cooperative priorities and inhibition control levels to each rivet according to the weighted grouping strategy, and grouping rivets with the same cooperative priority into the same control group through a priority matching algorithm to obtain a rivet cooperative riveting group.

[0007] Preferably, the rivet interaction strength matrix is used to construct an inhibition-cooperation relationship network between rivets, mutually inhibited rivet sets and mutually cooperative rivet sets are identified, and rivets are differentially weighted according to inhibition-cooperation relationship strength to obtain a weighted grouping strategy, including: setting inhibition relationship thresholds and cooperative relationship thresholds according to the strength value distribution in the rivet interaction strength matrix, marking rivet pairs exceeding the cooperative relationship threshold as cooperative node pairs, marking rivet pairs exceeding the inhibition relationship threshold and having negative interaction as inhibition node pairs, and obtaining a rivet relationship network topology; Based on the rivet relationship network topology, the network connectivity and centrality index of each rivet are analyzed, core collaborative rivets with multiple collaborative connections and key inhibitory rivets with multiple inhibitory connections are identified, and the influence propagation coefficient of each rivet in the network is calculated to obtain the rivet network influence distribution data; According to the rivet network influence distribution data, a basic weight value is assigned to each rivet, a collaborative enhancement weight is given to the core collaborative rivet, and an inhibitory control weight is given to the key inhibitory rivet. The differentiated weight coefficient of each rivet is generated through the weight normalization algorithm to obtain a weighted grouping strategy.

[0008] Preferably, the stress wave propagation delay time is calculated according to the spatial distribution of the rivet cooperative pressure riveting group, and a timing cascade control instruction is generated to obtain multiple groups of cooperative control sequences, including: Calculating the propagation paths and propagation velocities of stress waves between the groups based on the spatial distribution of the rivet cooperative riveting groups and the anisotropic parameters of the workpiece material, optimizing the paths for different propagation directions based on the propagation paths and propagation velocities, and obtaining a stress wave propagation path diagram between the groups; Calculating the arrival time and amplitude attenuation of the stress wave on each propagation path based on the inter-group stress wave propagation path diagram and the expected values ​​of the press riveting force of each rivet collaborative press riveting group, and correcting the propagation delay time based on the change in the dynamic stiffness of the material to obtain corrected propagation delay time data; A multi-layer cascade trigger strategy is constructed based on the corrected propagation delay time data, cascade priorities and trigger time windows are assigned to each rivet collaborative press riveting group, and startup control instructions and collaborative control instructions for each group are generated according to the arrival timing of the stress wave to obtain a hierarchical cascade control instruction set; The timing of each rivet cooperative riveting group is arranged according to the hierarchical cascade control instruction set, and the start control instruction and the cooperative control instruction are sorted according to the cascade priority combination to obtain multiple groups of cooperative control sequences.

[0009] Preferably, the cascade riveting is performed based on the multiple sets of coordinated control sequences, the stress wave superposition effect is monitored in real time, the stress concentration position is predicted, and the riveting parameters are dynamically modulated in the predicted stress concentration area to obtain the stress wave coordinated control state, including: Initiate the cascade riveting process of each rivet collaborative riveting group according to the multiple groups of coordinated control sequences, obtain the stress wave amplitude and frequency characteristics during the riveting execution of each group, identify the propagation direction and superposition area of ​​the stress wave, and obtain real-time stress wave distribution data; Analyzing the superposition pattern of multi-source stress waves based on the real-time stress wave distribution data, identifying constructive superposition areas and destructive superposition areas, calculating the stress concentration degree and evolution trend of each superposition area, and obtaining stress wave superposition effect analysis results; Based on the stress wave superposition effect analysis result and the process state of cascade riveting, the stress concentration position and concentration intensity at the next time are predicted by a stress propagation trajectory extrapolation algorithm, a high-risk stress concentration area needing intervention modulation is identified, and stress concentration prediction data is obtained; According to the stress concentration prediction data, the rivets in the high-risk stress concentration area are subjected to dynamic degradation of riveting force and self-adaptive adjustment of riveting speed, and the rivets in the adjacent area are subjected to compensatory parameter enhancement, and dynamic modulation parameter configuration is obtained; According to the dynamic modulation parameter configuration, the control instructions of each rivet cooperative riveting group are updated, the modulated riveting parameters are applied to the subsequent cascade riveting process, and the stress wave cooperative control state is obtained.

[0010] Preferably, based on the stress wave superposition effect analysis result and the process state of cascade riveting, the stress concentration position and concentration intensity at the next time are predicted by a stress propagation trajectory extrapolation algorithm, a high-risk stress concentration area needing intervention modulation is identified, and stress concentration prediction data is obtained, including: According to the stress concentration degree and evolution trend in the stress wave superposition effect analysis result, the position coordinates, intensity change rate and propagation direction vector of each stress concentration point are extracted, the motion trajectory equation and intensity attenuation equation of the stress concentration point are established, and stress propagation trajectory parameters are obtained; Based on the stress propagation trajectory parameters and the process state of cascade riveting, the displacement and intensity change of each stress concentration point within the next riveting time step are calculated by a trajectory extrapolation algorithm, the appearance position and initial intensity of the newly generated stress concentration point are predicted, and stress concentration state prediction results are obtained; According to the stress concentration state prediction results, a high-risk stress concentration threshold is set, stress concentration areas with predicted intensity exceeding the threshold are marked as high-risk areas, and the high-risk areas are prioritized according to the risk degree, and stress concentration prediction data is obtained.

[0011] Preferably, according to the stress wave cooperative control state, the change of the electrochemical potential difference of the dissimilar material interface is monitored, the electrochemical instability risk is predicted, and the interface pressure is self-adaptively adjusted in the high-risk area, and the interface electrochemical equilibrium state is obtained, including: According to the stress distribution data in the stress wave cooperative control state and the dissimilar material interface type of each rivet position, the real-time change data of the electrochemical potential difference of each dissimilar material interface area is obtained, the interface area with electrochemical potential difference gradient exceeding the threshold is identified, and an electrochemical potential difference distribution map is obtained; Based on the electrochemical potential difference distribution map, the electrochemical communication path between adjacent rivets is analyzed, the high-risk communication area and the electrochemical potential difference amplification area forming the galvanic corrosion loop are identified, the corrosion current density and diffusion rate of each communication area are calculated, and electrochemical instability risk evaluation data is obtained; According to the corrosion current density and diffusion rate in the electrochemical instability risk assessment data, the instability time and instability degree of each high-risk connected region are predicted by an electrochemical kinetics algorithm, a critical instability region requiring emergency intervention is identified, and an electrochemical instability prediction result is obtained; Based on the electrochemical instability prediction result, interface pressure enhancement adjustment is performed on the rivets in the critical instability region, and pressure gradient optimization adjustment is performed on the electrochemical potential difference amplification region, so that a differential interface pressure adjustment strategy is obtained. According to the differential interface pressure adjustment strategy, the pressure state of each heterogeneous interface region is updated, the high-risk electrochemical connected path is cut off through pressure redistribution, and an interface electrochemical equilibrium state is obtained.

[0012] Preferably, according to the stress wave cooperative control state and the interface electrochemical equilibrium state, global residual stress optimization adjustment is performed on each rivet cooperative riveting group, so that a system balance control state is obtained, including: According to the stress wave cooperative control state and the interface electrochemical equilibrium state, a comprehensive stress state and an electrochemical stability index of each rivet position are calculated through a multi-physical field information fusion algorithm, a residual stress distribution map and an electrochemical stability distribution map of the workpiece whole domain are generated, and system state comprehensive evaluation data is obtained. Based on the system state comprehensive evaluation data, residual stress exceeding area and electrochemical instability area are identified, the influence weight and the transfer coefficient of each area on the adjacent rivet cooperative riveting group are calculated, the mutual influence relationship matrix between the rivet cooperative riveting groups is constructed, and a group coupling influence analysis result is obtained. According to the group coupling influence analysis result, a hierarchical optimization strategy is formulated, the rivet cooperative riveting group with high influence weight is preferentially adjusted, and the rivet cooperative riveting group with low influence weight is cooperatively compensated, so that a hierarchical residual stress adjustment scheme is obtained. Based on the hierarchical residual stress adjustment scheme, differential fine adjustment is performed on each rivet cooperative riveting group, residual stress is converged to a target distribution state through a stress redistribution algorithm, and the stability of the interface electrochemical equilibrium state is maintained, so that global optimization adjustment parameters are obtained. According to the global optimization adjustment parameters, the control state of each rivet cooperative riveting group is updated, and the system stability and balance are verified through a multivariable convergence criterion, so that a system balance control state is obtained.

[0013] The second aspect of the present application provides a control device for multi-riveting synchronous riveting, which comprises: A rivet grouping control module is used for calculating the interaction strength between rivets according to rivet position parameters and material parameters, functionally grouping a plurality of rivets, and obtaining a rivet cooperative riveting group. a timing cascade control module configured to calculate stress wave propagation delay time according to the spatial distribution of the rivet cooperative riveting groups, generate timing cascade control instructions, and obtain a plurality of cooperative control sequences; a stress wave cooperative control module configured to perform cascade riveting based on the plurality of cooperative control sequences, monitor stress wave superposition effect in real time and predict stress concentration positions, dynamically modulate riveting parameters in the predicted stress concentration areas, and obtain a stress wave cooperative control state; an electrochemical balance control module configured to monitor changes in electrochemical potential difference of the dissimilar material interface according to the stress wave cooperative control state, predict electrochemical instability risks, and perform interface pressure self-adaptive adjustment in high-risk areas, and obtain an interface electrochemical balance state; a global optimization control module configured to perform global residual stress optimization adjustment on each rivet cooperative riveting group according to the stress wave cooperative control state and the interface electrochemical balance state, and obtain a system balance control state.

[0014] The third aspect of the present application provides a multi-riveting synchronous riveting control device, comprising: a memory and at least one processor, the memory storing instructions, and the memory and the at least one processor being interconnected by a circuit; the at least one processor invokes the instructions in the memory to enable the multi-riveting synchronous riveting control device to perform the steps of the multi-riveting synchronous riveting control method described above.

[0015] The technical scheme provided by the embodiments of the present application first calculates the rivet interaction strength according to the rivet position parameters and material parameters, functionally groups a plurality of rivets to obtain rivet cooperative riveting groups. This step changes the traditional spatial proximity grouping into intelligent grouping based on physical action mechanism. By quantitatively analyzing the stress propagation strength and electrochemical coupling strength between rivets, it is identified that which rivets have strong interaction relationship and which rivets have weak mutual influence, so as to decompose the complex multi-riveting system into several control units with high internal cooperation and relatively independent groups. This grouping method fundamentally avoids the problems of stress superposition and electrochemical connection caused by mutual interference of rivets in traditional synchronous riveting.

[0016] On a packet basis, the scheme calculates stress wave propagation delay time according to the spatial distribution of rivet cooperative riveting groups, generates time sequence cascade control instructions to obtain a plurality of cooperative control sequences, and then performs cascade riveting based on the sequence and monitors stress wave superposition effect in real time, and through prediction of stress concentration position, dynamically modulates riveting parameters of the relevant area to obtain a stress wave cooperative control state. This process converts the physical propagation delay from the traditional "synchronous obstacle" to "control resources", uses the natural propagation characteristics of stress waves in materials, makes each rivet group start riveting at the moment when the stress wave signal of the previous group is received, forms a wave front guided cooperative effect, not only eliminates the destructive superposition of stress waves, but also uses stress waves to create a favorable prestressed environment for the deformation of subsequent rivet groups. At the same time, through real-time monitoring and prediction mechanism, the system can modulate parameters before the stress concentration is formed, and actively controls the negative effects of instantaneous mechanical coupling. In terms of electrochemical control, the scheme monitors the change of electrochemical potential difference of the interface according to the stress wave cooperative control state, predicts the risk of electrochemical instability and performs interface pressure self-adaptive adjustment on the high-risk area to obtain an interface electrochemical equilibrium state, and through the dynamic correlation between mechanical stress state and electrochemical response, the active regulation of the electrochemical coupling process is realized. The whole scheme optimizes and adjusts the global residual stress of each rivet cooperative riveting group according to the stress wave cooperative control state and the interface electrochemical equilibrium state, integrates the local control effect into the system-level optimization result, and ensures that the multi-riveted structure can still maintain the designed geometric accuracy and long-term electrochemical stability after releasing the constraint. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 An embodiment schematic diagram of a control method for multi-riveted synchronous riveting in the embodiment of the application; Figure 2 An embodiment schematic diagram of a control device for multi-riveted synchronous riveting in the embodiment of the application; Figure 3 An embodiment schematic diagram of a control device for multi-riveted synchronous riveting in the embodiment of the application. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0019] An embodiment of the application provides a control method for multi-riveted synchronous riveting. Figure 1A flow chart of the control method of the multi-rivet synchronous riveting provided by an embodiment of the present application is shown in the figure. In this embodiment, the method comprises the following steps: Referring to Figure 1 calculating the rivet interaction strength according to the rivet position parameters and the material parameters, functionally grouping the multiple rivets, and obtaining a rivet cooperative riveting group; In an embodiment of the present application, the above steps specifically comprise: obtaining the spatial coordinates of the positions of the rivets and the line direction angles, and calculating the mechanical stress propagation strength and the electrochemical coupling strength between the rivets according to the spatial coordinates, the line direction angles, and the electrochemical activity difference of the dissimilar material interfaces and the workpiece material thickness distribution parameters; According to the mechanical stress propagation strength and the electrochemical coupling strength, the comprehensive interaction strength between the rivets is calculated by a weighted fusion algorithm, the dominant path of stress wave propagation and the high-risk channel of electrochemical connection are identified, and a rivet interaction strength matrix is obtained; Based on the rivet interaction strength matrix, a rivet interaction inhibition-cooperation relationship network is constructed, the rivet sets that mutually inhibit and the rivet sets that mutually cooperate are identified, the rivets are differentially weighted according to the inhibition-cooperation relationship strength, and a weighted grouping strategy is obtained; According to the weighted grouping strategy, the cooperative priority and the inhibition control level of each rivet are assigned, and the rivets with the same value interval of the cooperative priority are grouped into the same control group through a priority matching algorithm, and a rivet cooperative riveting group is obtained.

[0020] The following specifically describes the steps involved in the above embodiment: The three-dimensional space coordinates of each rivet position are obtained by a three-coordinate measuring machine, and a rectangular coordinate system with the lower left corner of the workpiece as the origin is established. The direction angle of the connecting line is obtained by geometric calculation: the position vectors of any two rivets are calculated, and then the angle between the vectors and the rolling direction of the material is calculated. The mechanical stress propagation intensity calculation is based on the stress wave propagation theory in material mechanics. The propagation of stress wave in metal material has directionality, and the propagation speed along the rolling direction is about 5900 m / s, and the vertical direction is about 5200 m / s. The propagation intensity is related to the distance and the direction angle: taking the standard distance of 20 mm between adjacent rivets as the benchmark, the propagation intensity is set to 1.0, and the intensity decays exponentially every 10 mm, with a decay coefficient of 0.85. The direction correction uses the cosine function: when the angle between the connecting line and the rolling direction is 0°, the correction coefficient is 1.0, and when the angle is 90°, the correction coefficient is 0.7. The electrochemical coupling strength calculation needs to determine the type of dissimilar material interface, and the potential difference value is obtained by consulting the standard electrode potential table of the material. The standard potential difference between aluminum alloy and carbon steel is about 0.8 V, and that between aluminum alloy and stainless steel is about 0.4 V. The thickness distribution parameters of the workpiece material are directly obtained from the design drawings or process documents. For standardized aviation structures, the thickness parameters of different regions have been determined and recorded in the design stage, and the corresponding material thickness values of each rivet position can be quickly obtained by table lookup. This step converts the complex physical interaction relationship between rivets into calculable numerical parameters, providing accurate input data for the subsequent grouping algorithm.

[0021] The weighted fusion algorithm combines the mechanical stress propagation intensity and the electrochemical coupling intensity. The specific operation is: comprehensive interaction intensity = mechanical weight × mechanical stress propagation intensity + electrochemical weight × electrochemical coupling intensity. The weight coefficients are determined according to the service environment of the aviation structure: for the fuselage structure mainly bearing flight load, the mechanical weight is 0.7 and the electrochemical weight is 0.3; for the outer skin structure exposed to high humidity environment, the mechanical weight is 0.6 and the electrochemical weight is 0.4. The advantage path identification is realized by the traversal algorithm: starting from any rivet, find the rivet directly connected and with interaction intensity greater than 0.6, and then continue to find the next level of connection from these rivets until no connection meeting the strength requirement can be found, and the connection sequence formed is the advantage path. The identification of high-risk channels of electrochemical connectivity is based on regional connectivity judgment: when the electrochemical coupling intensity of adjacent dissimilar material interface rivets (distance less than 50 mm) is greater than 0.5, the region formed by these rivets is marked as a high-risk channel. The interaction intensity matrix is stored in a two-dimensional array, and the matrix size is n × n (n is the total number of rivets), and the element in the i-th row and j-th column of the matrix represents the comprehensive interaction intensity between the i-th rivet and the j-th rivet. This step unifies the multi-dimensional physical parameters into a single interaction intensity index, simplifying the subsequent network analysis calculation.

[0022] The inhibition-synergy relationship network adopts an adjacency list data structure to store the relationship between rivets. The judgment standard of synergy relationship is that the comprehensive interaction intensity is greater than 0.6, and the two rivets are on the same stress propagation dominant path, which indicates that the stress superposition effect of simultaneous riveting of the two rivets is beneficial to deformation homogenization. The judgment standard of inhibition relationship is that the interaction intensity is greater than 0.5, but the stress propagation directions of the two rivets will form cross interference in a certain area, which indicates that simultaneous riveting will aggravate local stress concentration. The connectivity of each rivet in the network is defined as the number of other rivets directly connected to the rivet, and a high connectivity indicates that the rivet has strong interaction with multiple positions. The centrality index is obtained by calculating the frequency of the rivet in all shortest paths, and the rivet with high frequency plays a key role in network information transmission. The differentiated weight allocation rule is that the rivet with a connectivity greater than 4 and a centrality index greater than 0.2 is a core synergy rivet, and is allocated a weight of 1.3; the rivet with a connectivity greater than 3 but mainly inhibition relationship is a key inhibition rivet, and is allocated a weight of 0.7; the remaining rivets are allocated a standard weight of 1.0. This step reveals the internal law of the complex interaction between rivets through network topology analysis, providing a theoretical basis for scientific grouping.

[0023] The synergy priority allocation adopts a weighted scoring method: the basic score of each rivet is 5 points, the rivet with a network weight greater than 1.0 adds 2 points, the rivet with a network weight less than 1.0 subtracts 2 points, the connectivity increases by 0.5 points for each increase of 1, and the centrality index increases by 1 point for each increase of 0.1. The final score is the synergy priority. The inhibition control level is specially set for the inhibition relationship rivets: the rivet with more than 3 inhibition relationships is set as a strong inhibition level, the rivet with 2-3 inhibition relationships is set as a medium inhibition level, and the rivet with 1 inhibition relationship is set as a weak inhibition level. The priority matching adopts numerical interval division: the rivet with a priority of 8-10 points is in a high priority group, the rivet with a priority of 5-7 points is in a medium priority group, and the rivet with a priority of 1-4 points is in a low priority group. In each priority group, the rivets are further subdivided according to their spatial positions: the center of gravity of all rivets in the group is calculated, and a circular area with a radius of 30 mm is divided with the center of gravity as the center. The rivets located in the same area are grouped into a rivet synergy riveting group. The number of rivets in each synergy riveting group is controlled within 3-6, which ensures that the synergy effect can be achieved and the implementation can be controlled. This step converts the abstract results of network analysis into specific control grouping schemes, realizing the effective conversion from theoretical analysis to engineering application.

[0024] In an embodiment of the present application, the inhibition-synergy relationship network between rivets is constructed based on the rivet interaction intensity matrix, the mutually inhibited rivet set and the mutually synergistic rivet set are identified, the rivets are differentiated in weight allocation according to the inhibition-synergy relationship intensity, and a weighted grouping strategy is obtained, including: According to the strength value distribution in the rivet interaction strength matrix, a suppression relationship threshold and a synergistic relationship threshold are set, rivet pairs exceeding the synergistic relationship threshold are marked as synergistic node pairs, and rivet pairs exceeding the suppression relationship threshold and having a negative interaction value are marked as suppression node pairs, to obtain a rivet relationship network topology structure; Based on the rivet relationship network topology structure, network connectivity and centrality index of each rivet are analyzed, core synergistic rivets with multiple synergistic connections and key suppression rivets with multiple suppression connections are identified, and influence propagation coefficients of each rivet in the network are calculated, to obtain rivet network influence distribution data; According to the rivet network influence distribution data, a basic weight value is assigned to each rivet, a synergistic enhancement weight is given to the core synergistic rivet, and a suppression control weight is given to the key suppression rivet, and a differentiated weight coefficient of each rivet is generated through a weight normalization algorithm, to obtain a weighted grouping strategy.

[0025] The following specifically describes the steps involved in the above embodiments: The setting of the suppression relationship threshold and the synergistic relationship threshold is based on the statistical distribution characteristics of the values in the rivet interaction strength matrix. By calculating the average value and the standard deviation of all non-zero elements in the matrix, the synergistic relationship threshold is set to the average value plus 0.5 times the standard deviation, and the suppression relationship threshold is set to the average value plus 0.3 times the standard deviation. The marking process of the synergistic node pairs is as follows: traverse the interaction strength matrix, and mark the rivet pairs with a value greater than the synergistic relationship threshold and a positive value as synergistic node pairs, indicating that the stress superposition effect produced by the simultaneous press riveting of the two rivets is beneficial to deformation homogenization. The marking of the suppression node pairs needs to satisfy two conditions at the same time: the interaction strength is greater than the suppression relationship threshold and the value is negative, and the negative value indicates that the stress propagation of the two rivets will interfere with each other and exacerbate local stress concentration. The rivet relationship network topology structure is represented by a graph data structure, each rivet is a network node, and the synergistic node pairs and the suppression node pairs are connected to the corresponding nodes by different types of edges. For example, in a 48-rivet wing skin, 15 synergistic node pairs and 8 suppression node pairs are identified after threshold judgment, forming a network topology structure containing 48 nodes and 23 edges. This step converts continuous numerical interaction strength into discrete relationship types, eliminating the interference of small numerical differences on the analysis results, making the subsequent network analysis more stable and reliable.

[0026] The network connectivity is defined as the number of rivets directly connected to a certain rivet, which is obtained by counting the number of edges of each node in the network topology. The centrality index adopts the betweenness centrality calculation method: for the shortest path between any two nodes in the network, the proportion of the number of paths passing through the target rivet to the total number of paths is counted, the higher the proportion, the greater the importance of the rivet in the network information transmission. The identification criteria of core collaborative rivets are: the number of collaborative connections is greater than 3 and the centrality index is greater than 0.15, which means that the rivet has a beneficial collaborative relationship with multiple other rivets and plays a key role in the network. The identification criteria of key suppression rivets are: the number of suppression connections is greater than 2 and these suppression connections are distributed in different directions, which means that the rivet will have a negative impact on multiple surrounding areas. The influence propagation coefficient is obtained by recursive calculation: starting from the target rivet, calculate the weight sum of the directly connected rivets, then calculate 0.5 times the weight sum of the second level connected rivets, 0.25 times the weight sum of the third level connected rivets, and so on until the weight contribution is less than 0.01, the sum of all weight sums is the influence propagation coefficient. The rivet network influence distribution data records the connectivity, centrality index and influence propagation coefficient of each rivet in table form. This step reveals the importance of each rivet in the network through quantitative analysis, providing a scientific basis for differentiated weight allocation.

[0027] The allocation of basic weight values adopts a normalization method: the influence propagation coefficients of all rivets are standardized to make the numerical value distributed between 0.5-1.5, and the standardized value is the basic weight value. The collaborative enhancement weight is specially set for core collaborative rivets, which is multiplied by an enhancement coefficient of 1.2 based on the basic weight value, reflecting the positive role of these rivets in collaborative control. The suppression control weight is set for key suppression rivets, which is multiplied by a control coefficient of 0.8 based on the basic weight value, reducing the influence of these rivets in the grouping to reduce the negative effect. The weight normalization algorithm ensures that the sum of all rivet weight values is equal to the total number of rivets, and the specific operation is: calculate the sum of all differentiated weight coefficients, then divide the total number of rivets by the sum to get the normalization factor, multiply each rivet's weight coefficient by the normalization factor to get the final differentiated weight coefficient. The weighted grouping strategy records the coordinate position, network type (core collaboration, key suppression or ordinary) and differentiated weight coefficient of each rivet in table form, providing a complete data basis for subsequent priority allocation and grouping operations. This step realizes the conversion from network topology analysis to weight quantization, which converts the abstract network relationship into numerical parameters that can be used for algorithm calculation, making the intelligent grouping based on physical interaction an operational engineering method.

[0028] Please continue to refer to Figure 1 , according to the spatial distribution of the rivet collaborative rivet group, the stress wave propagation delay time is calculated, the time sequence cascade control instruction is generated, and the multi-group collaborative control sequence is obtained. In one embodiment of the present application, the above steps specifically include: According to the spatial distribution of the rivet cooperative press riveting groups and the anisotropy parameters of the workpiece material, the propagation path and propagation speed of the stress wave between groups are calculated, the path is optimized and selected based on the propagation path and propagation speed in different propagation directions, and a group stress wave propagation path diagram is obtained; According to the group stress wave propagation path diagram and the press riveting force expected value of each rivet cooperative press riveting group, the arrival time and amplitude attenuation of the stress wave on each propagation path are calculated, the propagation delay time is corrected according to the dynamic stiffness change of the material, and the corrected propagation delay time data is obtained; Based on the corrected propagation delay time data, a multi-level cascade triggering strategy is constructed, the cascade priority and trigger time window are assigned to each rivet cooperative press riveting group, the start control instruction and cooperative control instruction of each group are generated according to the arrival time of the stress wave, and a hierarchical cascade control instruction set is obtained; According to the hierarchical cascade control instruction set, the timing arrangement is performed on each rivet cooperative press riveting group, the start control instruction and cooperative control instruction are combined and sorted according to the cascade priority, and a multi-group cooperative control sequence is obtained.

[0029] The following specifically describes the steps involved in the above embodiment: The stress wave propagation path calculation between groups is based on the barycentric position and spatial distribution characteristics of rivet cooperative groups. First, the geometric barycentic coordinates of each rivet cooperative group are calculated as the representative position point of the group, and then the straight-line distance and connecting direction between any two groups are calculated. The anisotropic parameters of the workpiece material include the elastic modulus and Poisson's ratio in different directions. For aluminum alloy sheets used in aviation, the elastic modulus along the rolling direction is about 72 GPa, about 68 GPa perpendicular to the rolling direction, and about 70 GPa at 45°. The stress wave propagation velocity is calculated based on the elastic wave theory, and the longitudinal wave propagation velocity is equal to the square root of the elastic modulus divided by the material density. The propagation velocity in different directions differs by 5-8%. The path optimization selection process is as follows: for the connection between any two rivet cooperative groups, the straight-line path, the curved path around the thickness variation area, and the polyline path along the material principal stress direction are calculated, the propagation time and energy loss of these paths are compared, and the path with the shortest propagation time and energy loss less than 20% is selected as the optimized path. The inter-group stress wave propagation path diagram is represented in the form of a directed graph, with nodes representing rivet cooperative groups and edges representing stress wave propagation paths. The edge is marked with the propagation distance and the expected propagation time. For example, in a certain fuselage section with 6 rivet cooperative groups, the straight-line path from group A to group B is 45 mm long and takes 7.8 microseconds to propagate, while the path around the stiffener is 52 mm long and takes 9.1 microseconds to propagate. The straight-line path is selected as the optimized path. This step simplifies the complex three-dimensional stress wave propagation problem into a calculable path selection problem, providing a physical basis for accurate timing control.

[0030] The stress wave arrival time calculation is based on the path length and propagation velocity data in the inter-group stress wave propagation path diagram. For each propagation path, the path length is divided by the stress wave propagation velocity in the corresponding direction to obtain the basic arrival time. The amplitude attenuation calculation considers both geometric diffusion and material damping: the amplitude attenuation caused by geometric diffusion is inversely proportional to the square root of the propagation distance, and the attenuation caused by material damping changes exponentially, with the damping coefficient determined according to the material type and frequency. The expected value of the press-in force is obtained by consulting the process specification, and the standard press-in force of different specifications of rivets ranges from 8 to 25 kN. The greater the press-in force, the higher the initial amplitude of the stress wave generated. Material dynamic stiffness variation refers to the phenomenon of stiffness reduction due to plastic deformation and temperature rise during the press-in process. The dynamic stiffness decreases by 10-15% compared to the static stiffness, which slows down the stress wave propagation speed by about 5%. The propagation delay time correction process is as follows: multiply the basic arrival time by the dynamic stiffness correction coefficient 1.05 to obtain the actual propagation delay time considering the material state change. The corrected propagation delay time data records the propagation delay time, amplitude attenuation coefficient, and propagation path information between each pair of rivet cooperative groups in table form. This step eliminates the influence of material nonlinear characteristics on timing control through accurate calculation, ensuring the accuracy of the cascade trigger timing.

[0031] The multi-level cascade trigger strategy is a hierarchical timing control method, which divides all rivet collaborative groups according to the order of stress wave propagation. The cascade priority assignment is based on the topological sorting algorithm: the first level is set as priority 1, i.e. the rivet collaborative groups that start the riveting first, which have no stress wave propagation relationship or are independent of each other; the second level priority is set as 2, i.e. the groups that start after receiving the stress wave of the first level; and so on until all groups are assigned a priority. The trigger time window is defined as the time range in which a rivet collaborative group can start riveting, the start time is the time when the previous stress wave is received, and the end time is 50 microseconds after that time, which ensures that the stress wave effect is fully utilized while avoiding the effect disappearing. The start control instruction contains the riveting group number, start time and riveting force parameters, and the collaborative control instruction contains the synchronization deviation tolerance range of each rivet in the group and the riveting speed parameter. In the instruction generation process, the optimal start time of each rivet collaborative group is calculated according to the modified propagation delay time data, ensuring the continuity and effectiveness of the stress wave propagation chain. The hierarchical cascade control instruction set arranges all control instructions in time sequence to form a complete cascade riveting timing scheme. This step converts the physical propagation delay into a control advantage, enabling each rivet collaborative group to perform riveting operations in the optimal stress environment.

[0032] The timing arrangement process reorganizes the instructions in the hierarchical cascade control instruction set according to the execution priority and time sequence. First, all instructions are sorted according to the cascade priority, with priority 1 instructions at the front, followed by priority 2 instructions, and so on. Within the same priority, a secondary sorting is performed according to the start time to ensure that the instructions within the same level are executed in the correct time sequence. The pairing relationship between the start control instruction and the collaborative control instruction needs to be handled during the combined sorting process: each start control instruction is followed by the corresponding collaborative control instruction, forming an instruction pair to avoid the situation of starting without collaborative control. The generation of multiple group collaborative control sequences uses the time slicing method: the entire riveting process is time-sliced with 10 microsecond intervals, and each time slice contains all control instructions that need to be executed in that period, forming multiple parallel control sequences. For example, in a structure containing 8 rivet collaborative groups, 4 control sequences of different priority levels are generated, the first level contains 2 independent rivet collaborative groups, the second level contains 3 groups, the third level contains 2 groups, and the fourth level contains 1 group, and the start time interval of each level is 15-25 microseconds. This step realizes the conversion from static control instructions to dynamic execution sequences, providing an accurate timing control scheme for actual cascade riveting operations.

[0033] Please continue to refer to Figure 1Based on the multiple groups of cooperative control sequences, cascade riveting is performed, stress wave superposition effect is monitored in real time, stress concentration positions are predicted, the predicted stress concentration areas are dynamically modulated in riveting parameters, and a stress wave cooperative control state is obtained; In an embodiment of the present application, the above steps specifically include: According to the multiple groups of cooperative control sequences, a cascade riveting process of each rivet cooperative riveting group is started, stress wave amplitude and frequency characteristics in each group of riveting execution process are obtained, stress wave propagation direction and superposition area are identified, and real-time stress wave distribution data are obtained; According to the real-time stress wave distribution data, a superposition mode of multiple source stress waves is analyzed, constructive superposition areas and destructive superposition areas are identified, stress concentration degrees and evolution trends of each superposition area are calculated, and stress wave superposition effect analysis results are obtained; Based on the stress wave superposition effect analysis results and the process state of cascade riveting, stress concentration positions and concentration intensities at the next moment are predicted through a stress propagation trajectory extrapolation algorithm, high-risk stress concentration areas that need to be intervened and modulated are identified, and stress concentration prediction data are obtained; According to the stress concentration prediction data, the rivets in the high-risk stress concentration areas are dynamically degraded in riveting force and self-adaptively adjusted in riveting speed, and the rivets in the adjacent areas are compensatorily enhanced in parameters, and dynamic modulation parameter configurations are obtained; According to the dynamic modulation parameter configurations, control instructions of each rivet cooperative riveting group are updated, the modulated riveting parameters are applied to subsequent cascade riveting processes, and a stress wave cooperative control state is obtained.

[0034] The following specifically describes the steps involved in the above embodiment: The cascade riveting process is initiated based on the timing arrangement of multiple coordinated control sequences. Each rivet group begins the riveting operation sequentially at predetermined time intervals. Stress wave amplitude and frequency characteristics are acquired using piezoelectric accelerometers. The sensors are mounted on the workpiece surface 15-20 mm from the rivets, with a sampling frequency set to 100 kHz to capture the complete stress wave signal. Stress wave amplitude is measured by measuring the peak voltage of the sensor output signal, which is proportional to the stress wave intensity. Frequency characteristics are determined using fast Fourier transform analysis. The primary frequency of stress waves generated by riveting is concentrated in the 5-50 kHz range, with frequency distributions varying depending on material thickness and rivet specifications. Stress wave propagation direction is identified based on the arrival time difference of signals from multiple sensors. The stress wave propagation vector is calculated using a triangulation algorithm. Overlapping regions are identified by comparing the signal intensity distribution at different sensor locations. When the signals generated by multiple stress wave sources reach peak values ​​simultaneously in a given region, that region is marked as an overlap region. Real-time stress wave distribution data is recorded as a time series, with amplitude, frequency, and propagation direction information for each measurement point. Data is collected at a 10 microsecond interval. For example, in a wing assembly, when the leading rivet and press riveting group A are activated, a stress wave with an amplitude of 15 MPa and a main frequency of 25 kHz is generated. The wave propagates in a 45° northeast direction at a speed of 5800 m / s. This information is recorded in real time for subsequent analysis. This step converts the abstract stress wave phenomenon into a measurable digital signal, providing the data foundation for accurate superposition analysis.

[0035] The analysis of superposition patterns of multi-source stress waves is based on the principle of wave superposition: when two or more stress waves meet in space, a superposition effect occurs. Constructive superposition regions are defined as areas where multiple stress waves have the same or similar phases, where the superposition of peaks increases the amplitude of the composite wave. This is determined by a composite wave amplitude greater than 1.5 times the amplitude of an individual stress wave. Destructive superposition regions are defined as areas where the stress waves have opposite phases, where the superposition of peaks and troughs decreases the amplitude of the composite wave. This is determined by a composite wave amplitude less than 0.7 times the amplitude of the largest individual stress wave. Superposition patterns are identified using a phase analysis algorithm: the instantaneous phases of the individual stress wave signals are calculated. Constructive superposition is defined when the phase difference is less than 30°, while destructive superposition is defined when the phase difference is greater than 150°. Stress concentration is expressed using the stress concentration coefficient (SCC), which is the ratio of the maximum stress to the average stress after superposition. Regions with a SCC greater than 2.0 indicate areas of high stress concentration. Evolutionary trends are calculated by the rate of change of the SCC within a time window. Regions with a rate of change greater than 0.1 per microsecond indicate rapidly increasing stress concentration. For example, in a certain overlapping region, the stress wave amplitude generated by rivet cooperative press riveting group A is 12 MPa and the phase is 0°, while the stress wave amplitude generated by rivet cooperative press riveting group B is 8 MPa and the phase is 15°. After the two waves are superimposed, the maximum amplitude reaches 19 MPa. This region is identified as a constructive superposition region with a stress concentration factor of 2.3. The stress wave superposition effect analysis results are recorded in the form of a regional map, recording the location, type, intensity, and evolution trend of each superposition region. This step reveals the complex stress wave interaction patterns in the synchronous press riveting of multiple rivets through quantitative analysis, providing a scientific basis for predictive control.

[0036] The stress propagation trajectory extrapolation algorithm is based on the physical laws of stress wave propagation and the results of the current superposition effect analysis. The progress status of the cascade riveting process includes the number of completed rivet co-pressing groups, groups currently in progress, and groups that have not yet started. The trajectory extrapolation process first analyzes the position coordinates and movement velocity of the current stress concentration point. The movement velocity is calculated by dividing the position difference between two consecutive time points by the time interval. The extrapolation algorithm uses a linear prediction method: assuming that the stress concentration point maintains its current movement direction and velocity for a short period of time, the predicted position at the next moment is the current position plus the velocity vector multiplied by the time step. The concentration intensity is predicted based on the stress decay law, taking into account the effects of material damping and geometric diffusion. The intensity decays exponentially with time, and the decay coefficient is determined by the material type. The identification criteria for high-risk stress concentration areas are: the predicted stress concentration intensity is greater than 80% of the material yield strength and the presence of unriveted rivets within the area. The prediction time step is set to 20 microseconds, which provides relatively stable stress wave propagation characteristics within this time range and high prediction accuracy. For example, at the current time t, a stress concentration point is located at the coordinates (25mm, 30mm), with a strength of 180MPa and a movement speed of 0.5mm per microsecond. It is predicted that at t+20 microseconds, this point will move to the coordinates (35mm, 30mm), with a strength decay of 165MPa. Because there are rivets to be riveted near this location and their strength exceeds 80% of the material's yield strength, this area is marked as a high-risk stress concentration area. The stress concentration prediction data records the predicted location, predicted strength, arrival time, and risk level information. This step realizes the transition from passive monitoring to active prediction, enabling the control system to take preventive measures before stress concentration forms.

[0037] The implementation of dynamic modulation is based on the high-risk area information identified in the stress concentration prediction data. Dynamic degradation of the press-in force refers to reducing the press-in force of the rivet in the high-risk stress concentration area by 15-25% from the standard value, and the degradation range is determined according to the predicted stress concentration intensity, and the higher the predicted intensity, the greater the degradation range. Adaptive adjustment of the press-in speed refers to reducing the press-in speed of the rivet in this area to 70-85% of the standard value, and the slower press-in speed can reduce the intensity of the instantaneous stress wave. The peripheral area refers to the area within 20-30 mm from the boundary of the high-risk area, and the rivets in these areas need to be compensated for parameter enhancement to maintain the overall press-in quality. The compensatory parameter enhancement includes increasing the press-in force by 5-10% and prolonging the holding time by 0.1-0.2 seconds, and the enhanced parameters ensure that the rivet connection strength in the peripheral area will not be affected by the parameter degradation of the high-risk area. The dynamic modulation parameter configuration records the modulated press-in force, press-in speed, holding time and start time of each rivet in the form of a parameter table. For example, in a certain high-risk area, the standard press-in force of rivet R15 is 15 kN, which is reduced to 12 kN after modulation, and the press-in speed is reduced from 8 mm / s to 6 mm / s, while the press-in force of peripheral rivets R12 and R18 is increased from 12 kN to 13 kN, and the holding time is extended from 0.8 seconds to 1.0 seconds. This step realizes the balance between local risk control and overall quality assurance through differentiated parameter modulation.

[0038] The update process of the control instructions replaces the new parameter values in the dynamic modulation parameter configuration with the corresponding parameters in the original control instructions of each rivet cooperative press-in group. The update operation uses parameter overlay: the rivet number, group information and basic timing arrangement of the original control instructions are kept unchanged, and only the adjustable parameters such as press-in force, press-in speed and holding time are modified. The modulated press-in parameters are transmitted to the corresponding riveting actuators through the field bus, and the actuators execute the subsequent press-in operation according to the new parameters. The timing control of parameter application uses instruction queue management: the press-in operation that has started remains unchanged, the press-in operation that has not started applies the new modulation parameters, and the press-in operation that is in progress decides whether to apply part of the new parameters according to the process stage. The stress wave cooperative control state refers to the new stress wave propagation and superposition relationship formed between each rivet cooperative press-in group under the action of dynamic modulation, which contains the modulated stress wave distribution, superposition effect and propagation characteristic information. The evaluation of the control state is achieved by comparing the stress concentration degree and distribution uniformity before and after modulation, and the evaluation result is used to verify the modulation effect and guide the optimization of subsequent control strategy. This step realizes the closed loop from prediction analysis to actual control, and enables the multi-riveting synchronous riveting system to have adaptive adjustment capability.

[0039] In an embodiment of the present application, the stress concentration prediction data is obtained by analyzing the stress wave superposition effect and the process state of the cascading riveting, predicting the stress concentration position and intensity at the next time step by a stress propagation trajectory extrapolation algorithm, identifying the high-risk stress concentration area that needs to be intervened and modulated, and including: According to the stress concentration degree and evolution trend in the stress wave superposition effect analysis result, the position coordinates, intensity change rate and propagation direction vector of each stress concentration point are extracted, the motion trajectory equation and intensity attenuation equation of the stress concentration point are established, and the stress propagation trajectory parameters are obtained; Based on the stress propagation trajectory parameters and the process state of the cascading riveting, the displacement and intensity change of each stress concentration point within the next riveting time step are calculated by a trajectory extrapolation algorithm, the appearance position and initial intensity of the newly generated stress concentration point are predicted, and the stress concentration state prediction result is obtained. According to the stress concentration state prediction result, a high-risk stress concentration threshold is set, the stress concentration area with a predicted intensity exceeding the threshold is marked as a high-risk area, the high-risk areas are prioritized according to the risk degree, and the stress concentration prediction data is obtained.

[0040] The following specifically describes the steps involved in the above embodiment: The coordinates of stress concentration points are extracted from the stress distribution diagrams generated by the stress wave superposition effect analysis results. Stress concentration points are defined as locations where the local stress reaches a peak value and exceeds the surrounding average stress by more than 1.5 times. The coordinates are expressed in the workpiece coordinate system, with the lower left corner of the workpiece as the origin. The x and y coordinates of each stress concentration point are recorded. The intensity change rate is calculated by dividing the intensity difference between the stress concentration point at two consecutive time points by the time interval. The time interval is set to 5 microseconds, which is short enough to capture the transient characteristics of stress changes. The propagation direction vector is determined by analyzing the position change of the stress concentration point over time. The direction of this vector is the propagation direction, calculated by calculating the vector difference between the positions of the two previous and next time points. The motion trajectory equation uses a linear fitting method: the position data of the stress concentration point within the last 20 microseconds are fitted by the least squares method to obtain a linear relationship between the position and time. The intensity decay equation is based on the attenuation law of stress waves in the material and adopts an exponential decay formula: the current intensity is multiplied by the time power of the attenuation coefficient. The attenuation coefficient is determined based on the damping properties of the material and is 0.95 per microsecond for aluminum alloy. For example, in a fuselage assembly, a stress concentration point was identified at coordinates (45mm, 32mm), with an intensity of 85 MPa, a strength change rate of -2 MPa per microsecond, a propagation direction vector at 30° northeast, and a velocity of 0.8 mm / microsecond. The stress propagation trajectory parameters are recorded in a data table, recording the trajectory equation coefficients, attenuation equation parameters, and current state information for each stress concentration point. This step transforms complex stress fluctuations into predictable mathematical relationships, enabling the calculation of future states.

[0041] The trajectory extrapolation algorithm is based on the motion trajectory equation and the intensity decay equation in the stress propagation trajectory parameters to make prediction calculation. The process state of cascaded rivet pressing includes the rivet cooperative pressing group number that is currently performing rivet pressing, the number of groups that have completed rivet pressing, and the group that is expected to start rivet pressing next and its start time. The next rivet pressing time step is defined as the time interval from the current time to the start of the next rivet cooperative pressing group, and the time step ranges from 15 to 30 microseconds. The displacement amount calculation is obtained by multiplying the propagation velocity vector by the time step, and the intensity change amount is calculated by the intensity decay equation to calculate the intensity decay value in the time step. The prediction of the newly generated stress concentration point is based on the rivet cooperative pressing group position that is about to start and the rivet pressing force parameters, and the initial intensity of the new stress concentration point is determined according to the empirical database, which is in a positive proportional relationship with the rivet pressing force, and the proportional coefficient is 8 MPa stress concentration per kilonewton. The prediction process also considers the interaction between the propagation trajectory of the existing stress concentration point and the newly generated point, and when the distance between the predicted positions of the two stress concentration points is less than 15 mm, the superposition effect of the two stress concentration points needs to be calculated. For example, there is currently a stress concentration point located at (40 mm, 25 mm) with an intensity of 70 MPa and a propagation velocity of 0.6 mm / microsecond, and after 20 microseconds, the point is predicted to move to (52 mm, 25 mm) with an intensity decay of 63 MPa; at the same time, a new stress concentration point with an intensity of 45 MPa is predicted to be generated at the coordinates (48 mm, 30 mm). The stress concentration state prediction result records the stress concentration point position, intensity, and interaction relationship at all predicted times. This step realizes accurate prediction from the current state to the future state, providing a time advance for the active control strategy.

[0042] The high-risk stress concentration threshold is set based on the mechanical properties and safety factors of the workpiece material. For aviation aluminum alloys with a yield strength of 280 MPa, the high-risk stress concentration threshold is set at 75% of the yield strength, or 210 MPa. This threshold ensures that control intervention occurs before stress concentrations reach dangerous levels. The threshold also considers the duration of the stress concentration point. Only areas with a predicted intensity exceeding the threshold and a duration greater than 10 microseconds are designated as high-risk. High-risk areas are designated using a regional boundary delineation method: a circular area with a radius of twice the material thickness, centered at the stress concentration point, is defined as the high-risk area boundary. Priority ranking is based on a risk assessment, calculated by combining the magnitude of the threshold exceedance and the impact area. Areas with greater threshold exceedances and wider impact areas receive higher priorities. The ranking algorithm uses a weighted scoring method, with the magnitude of the threshold exceedance accounting for 60% and the impact area accounting for 40%. The highest-scoring area is designated as priority 1, and the priority level decreases in descending order. For example, three high-risk areas were identified: Area A had a stress concentration intensity of 235 MPa, an impact radius of 8 mm, and a score of 8.2; Area B had a stress concentration intensity of 225 MPa, an impact radius of 12 mm, and a score of 7.8; and Area C had a stress concentration intensity of 220 MPa, an impact radius of 6 mm, and a score of 6.9. The ranking results were A, B, and C. The stress concentration prediction data was recorded in a priority list, including the location, intensity, impact radius, and treatment priority of each high-risk area. This step, through quantitative risk assessment, ensures that control resources are preferentially allocated to the most dangerous areas, achieving optimal utilization of limited control resources.

[0043] Please continue reading Figure 1 , monitoring the change of electrochemical potential difference at the interface of different materials according to the stress wave coordinated control state, predicting the risk of electrochemical instability and adaptively adjusting the interface pressure in high-risk areas to obtain the electrochemical equilibrium state of the interface; In one embodiment of the present invention, the above steps specifically include: According to the stress distribution data in the stress wave coordinated control state and the type of the dissimilar material interface at each rivet position, real-time change data of the electrochemical potential difference in each dissimilar material interface region is obtained, and the interface region where the electrochemical potential difference gradient exceeds the threshold is identified to obtain an electrochemical potential difference distribution map; Based on the electrochemical potential difference distribution map, the electrochemical connection paths between adjacent rivets are analyzed to identify high-risk connection areas and electrochemical potential difference amplification areas that form galvanic corrosion loops, and the corrosion current density and diffusion rate of each connection area are calculated to obtain electrochemical instability risk assessment data. According to the corrosion current density and diffusion rate in the electrochemical instability risk assessment data, the instability time and instability degree of each high-risk connected region are predicted by an electrochemical kinetics algorithm, a critical instability region requiring emergency intervention is identified, and an electrochemical instability prediction result is obtained; Based on the electrochemical instability prediction result, interface pressure enhancement adjustment is performed on the rivets in the critical instability region, and pressure gradient optimization adjustment is performed on the electrochemical potential difference amplification region, to obtain a differential interface pressure adjustment strategy; According to the differential interface pressure adjustment strategy, the pressure state of each dissimilar material interface region is updated, and the high-risk electrochemical connected path is cut off through pressure redistribution, to obtain an interface electrochemical equilibrium state.

[0044] The following specifically describes the steps involved in the above embodiments: The acquisition of the real-time change data of the electrochemical potential difference is based on the stress distribution information of each rivet position in the stress wave cooperative control state and the dissimilar material interface type. The dissimilar material interface type is determined directly by referring to the design drawing, and common types include aluminum alloy and steel connection, aluminum alloy and titanium alloy connection, etc. The electrochemical potential difference is measured by using the millivolt scale of the digital multimeter to measure the voltage difference between the rivet head and the workpiece surface. During the measurement, the positive probe of the multimeter contacts the surface of the rivet, and the negative probe contacts the surface of the workpiece. The voltage value displayed is the electrochemical potential difference. The real-time change data is obtained by recording the voltage value every 100 milliseconds to form time series data reflecting the dynamic change of the electrochemical state. The stress concentration area will increase the interface contact pressure, and the increase in pressure will squeeze the electrolyte layer between the interfaces, change the electrochemical reaction conditions, and thus cause the change of the electrochemical potential difference. The electrochemical potential difference gradient refers to the degree of spatial change of the potential difference between adjacent measurement points, and the calculation method is to divide the potential difference between two points by the distance between the two points. The gradient threshold is set to 0.5 millivolt per millimeter. When the gradient of adjacent measurement points exceeds this value, it indicates that there is a significant difference in electrochemical activity in this region. The identification of the super-threshold interface region is realized by comparing the gradient values of adjacent measurement points point by point. When the gradients of more than 3 consecutive measurement points all exceed the threshold, the region is marked as an electrochemical potential difference gradient super-threshold interface region. The electrochemical potential difference distribution map is represented by a color-coded plan view, with different colors representing different potential difference values, which facilitates intuitive identification of high-risk areas. This step converts complex electrochemical phenomena into quantifiable numerical data through standardized electrical measurement methods.

[0045] The electrochemical connectivity path analysis is based on the numerical distribution in the electrochemical potential difference distribution map and the rivet spatial layout. The connectivity path refers to the conductive channel in which the current can flow, and the judgment method is to check whether there is a continuous high potential difference area between adjacent rivets. The specific identification process is: draw a straight line connecting adjacent rivets on the electrochemical potential difference distribution map, and if the potential difference of all points on the straight line path is greater than 0.2V, it is considered that there is effective connection between the two rivets. The galvanic corrosion loop is a closed circuit formed by multiple rivets of different potentials through conductive medium, and the identification method is to find rivet combinations that can form a closed path. The judgment standard of high-risk connectivity area is: the maximum potential difference in the loop is more than 0.4V and the loop circumference is less than 50mm. The electrochemical potential difference amplification area refers to the area where the potential effect of multiple rivets is superimposed, causing local potential to abnormally increase, and the identification method is to compare the difference between the measured potential and the theoretical potential of a single rivet. The corrosion current density calculation uses Ohm's law: potential difference divided by resistance and then divided by contact area, and the resistance value is obtained by directly measuring between rivets with a resistance tester. The diffusion rate represents the movement speed of electrolyte in the interface gap, which is obtained by measuring the rate of change of electrolyte concentration over time. The electrochemical instability risk assessment data records the potential difference, current density and diffusion rate values of each connectivity area in table form. This step accurately identifies the dangerous connectivity area with corrosion threat through systematic path analysis.

[0046] The electrochemical instability prediction is based on the calculation of time and degree of corrosion current density and diffusion rate data. The instability time prediction uses the corrosion rate calculation method: first multiply the corrosion current density by the electrochemical equivalent of the material to get the corrosion rate, and then divide the corrosion rate by 10% of the material thickness to get the instability time. The instability degree uses the percentage of corrosion depth to material thickness to represent, and the corrosion depth is obtained by multiplying the corrosion rate by the preset time. The prediction algorithm considers the time characteristics of the corrosion process: the initial corrosion is faster, and the rate decreases due to the accumulation of corrosion products in the later period, and the long-term prediction result is adjusted by introducing a time correction coefficient of 0.8. The influence of diffusion rate is reflected by diffusion coefficient, and the faster the diffusion, the more sufficient the electrolyte replenishment, and the longer the corrosion duration. The judgment standard of critical instability area is: the prediction instability time is less than 24 hours and the instability degree exceeds 15%. The influence of temperature and humidity needs to be considered in the prediction process, and the corrosion rate increases by 100% for every 10℃ increase in temperature, and the corrosion rate increases by 20% for every 10% increase in humidity. These influences are included in the calculation through environmental correction coefficients. The electrochemical instability prediction results record the instability time, instability degree and risk level of each area in the form of risk list. This step realizes accurate prediction from the current state to the future risk through quantitative calculation.

[0047] The interface pressure adjustment is divided into pressure enhancement adjustment and pressure gradient optimization. The pressure enhancement adjustment is implemented for the critical instability region, and the specific operation is to increase the pressure riveting force and the pressure riveting depth of the rivet. The pressure riveting force enhancement is achieved by adjusting the pressure setting value of the hydraulic system, and the original setting value is increased by 10-20%. The increase range is determined according to the instability degree. The pressure riveting depth enhancement is achieved by prolonging the pressure riveting stroke, and the depth is increased by 0.1-0.2 mm based on the standard depth. The pressure gradient optimization adjustment is implemented for the electrochemical potential difference amplification region, and the principle is to reduce the spatial variation of the potential difference by adjusting the pressure of the rivet at different positions. The optimization method adopts differential pressure setting: the pressure at the position with high potential is reduced by 5-10%, and the pressure at the position with low potential is increased by 5-10%, so that the potential distribution in the region tends to be flat. The determination of the pressure adjustment amount is based on the pressure-potential response relationship: for every 1 MPa increase in pressure, the electrochemical potential difference changes by about 0.02 V. The differential interface pressure adjustment strategy records the pressure adjustment direction, adjustment amplitude and execution sequence of each rivet in the form of operation instructions. Through accurate mechanical parameter adjustment, the effective control of the electrochemical environment is realized.

[0048] The pressure state updating applies the adjustment strategy to the actual riveting process through the servo control system. The updating process includes three links of parameter transmission, actuator response and state confirmation. The parameter transmission sends the new pressure parameters to the corresponding riveting equipment controller through industrial Ethernet. The actuator response refers to the adjustment of the output pressure and displacement of the hydraulic or pneumatic system according to the new parameters. The state confirmation monitors the actual execution effect in real time through pressure sensors and displacement sensors. The pressure redistribution refers to the new pressure field distribution formed after the adjustment of the pressure of each rivet, and the effect of the redistribution is verified by measuring the actual pressure values of each point. The mechanism of cutting off the electrochemical communication path is based on the influence of pressure on electrical conductivity: increasing the pressure will squeeze the interface gap, reduce the space for the existence of electrolyte, and increase the contact resistance, thereby blocking the current path. The interface electrochemical equilibrium state refers to the state that the electrochemical potential difference of each dissimilar material interface after adjustment is within the safe range and there is no effective corrosion loop. The balance state verification is achieved by re-measuring the potential distribution and connectivity analysis, and when the potential gradient is less than the threshold value and there is no continuous conduction path, it is confirmed that the balance is reached. Through systematic pressure redistribution, the conditions for the occurrence of electrochemical corrosion are eliminated from the root.

[0049] Please continue to refer to Figure 1 , according to the stress wave cooperative control state and the interface electrochemical equilibrium state, the global residual stress optimization adjustment is performed on each rivet cooperative riveting group to obtain a system balance control state.

[0050] In an embodiment of the present application, the above steps specifically include: According to the stress wave cooperative control state and the interface electrochemical equilibrium state, a comprehensive stress state and an electrochemical stability index of each rivet position are calculated by a multi-physical field information fusion algorithm, a residual stress distribution map and an electrochemical stability distribution map of the workpiece whole domain are generated, and system state comprehensive evaluation data are obtained; Based on the system state comprehensive evaluation data, a residual stress exceeding standard area and an electrochemical instability area are identified, an influence weight and a transfer coefficient of each area on adjacent rivet cooperative riveting groups are calculated, a mutual influence relationship matrix between the rivet cooperative riveting groups is constructed, and a group coupling influence analysis result is obtained; According to the group coupling influence analysis result, a hierarchical optimization strategy is formulated, a priority adjustment is performed on the rivet cooperative riveting group with a high influence weight, a cooperative compensation adjustment is performed on the rivet cooperative riveting group with a low influence weight, and a hierarchical residual stress adjustment scheme is obtained; Based on the hierarchical residual stress adjustment scheme, differential fine adjustment is performed on each rivet cooperative riveting group, a stress redistribution algorithm is used to make the residual stress converge to a target distribution state, while the stability of the interface electrochemical equilibrium state is maintained, and global optimization adjustment parameters are obtained; According to the global optimization adjustment parameters, the control state of each rivet cooperative riveting group is updated, a multi-variable convergence criterion is used to verify the system stability and balance, and a system balance control state is obtained.

[0051] The following specifically describes the steps involved in the above embodiments: The multi-physical field information fusion algorithm unifies the data in the stress wave cooperative control state and the interface electrochemical equilibrium state. The fusion algorithm adopts a weighted average method to combine and calculate the stress data and the electrochemical data according to preset weights. The calculation process of the comprehensive stress state is as follows: the stress values of each rivet position in the stress wave cooperative control state are extracted, including the radial stress, the axial stress, and the shear stress three components, and the equivalent stress value is calculated as the comprehensive stress state index through the von Mises equivalent stress formula. The calculation of the electrochemical stability index is based on the potential difference and the corrosion current data in the interface electrochemical equilibrium state, and the stability index is normalized: the potential difference is divided by the critical corrosion potential of the material to obtain the potential stability coefficient, and the corrosion current is divided by the critical corrosion current to obtain the current stability coefficient, and the weighted average value of the two coefficients is the electrochemical stability index. The residual stress distribution map is represented in the form of a contour map, the horizontal and vertical coordinates are the spatial positions of the workpiece, the contour value represents the residual stress size, and the stress value is directly displayed through color coding. The electrochemical stability distribution map adopts the same coordinate system, and different colors are used to represent the high and low of the stability index. For example, in a certain wing assembly structure, the equivalent stress of rivet A position is 85 MPa, the electrochemical stability index is 0.75, the equivalent stress of rivet B position is 120 MPa, and the electrochemical stability index is 0.45, and the continuous distribution map of the entire workpiece area is generated through the interpolation algorithm. The system state comprehensive evaluation data records the comprehensive stress state, the electrochemical stability index, and the spatial coordinate information of each measurement point in the form of a data table. This step unifies the information of multiple physical fields into a comprehensive index that can be compared through data fusion technology, effectively integrating cross-field information.

[0052] The identification of the residual stress over-standard area and the electrochemical instability area is based on the threshold comparison in the system state comprehensive evaluation data. The judgment standard of the residual stress over-standard area is that the equivalent stress exceeds 60% of the material yield strength, and for the aviation aluminum alloy material, the yield strength is 280 MPa, so the over-standard threshold is set to 168 MPa. The judgment standard of the electrochemical instability area is that the electrochemical stability index is less than 0.6, and the threshold is determined based on long-term corrosion test data. The calculation of the influence weight is based on two factors: distance and intensity. The distance weight adopts an inverse proportional function, and the closer the distance, the greater the weight. The intensity weight is proportional to the stress or instability degree. The transmission coefficient represents the transmission efficiency of a region on the adjacent rivet cooperative press riveting group, and the calculation method is to divide the influence intensity by the propagation distance and multiply by the material transmission characteristic coefficient. The mutual influence relationship matrix adopts an n x n matrix form, where n is the total number of rivet cooperative press riveting groups, and the matrix element represents the mutual influence intensity between the corresponding groups. The matrix construction process is to calculate the influence weight and transmission coefficient of each over-standard area or instability area to each rivet cooperative press riveting group, and fill the calculation results into the corresponding position of the matrix. For example, three residual stress over-standard areas and two electrochemical instability areas are identified, the influence weight of the over-standard area S1 on the rivet cooperative press riveting group G2 is 0.8, and the transmission coefficient is 0.6, so the element of the first row and the second column in the mutual influence relationship matrix is 0.48. The analysis results of the group coupling effect are represented in the form of matrix and influence diagram, and the influence diagram connects the rivet cooperative press riveting groups with significant influence relationship with arrows. This step reveals the influence mode of each problem area on the whole system through quantitative analysis, and provides a scientific basis for the formulation of targeted optimization strategy.

[0053] The hierarchical optimization strategy is formulated based on the interdependence relationship matrix in the coupling effect analysis results. The high-impact-weight rivet collaborative riveting group is defined as the group with the total impact weight greater than 2.0 in the interdependence relationship matrix. These groups have a significant impact on the overall system and need priority adjustment. Priority adjustment includes two aspects: adjustment of riveting sequence and adjustment of riveting parameters. Sequence adjustment refers to advancing the riveting sequence of high-impact-weight groups to reduce their adverse effects on subsequent groups. Parameter adjustment refers to appropriately reducing the riveting force or riveting speed of these groups to reduce the intensity of the stress wave generated. The low-impact-weight rivet collaborative riveting group is defined as the group with a total impact weight less than 1.0. These groups have less impact on the overall system, and a collaborative compensation adjustment strategy is adopted. Collaborative compensation adjustment refers to appropriately increasing the riveting parameters of these groups to compensate for the deficiencies caused by the reduction of high-impact-weight group parameters, ensuring that the overall connection quality is not affected. The hierarchical level is divided based on the impact weight range: the first layer is the high-impact-weight group, the second layer is the medium-impact-weight group (total weight 1.0-2.0), and the third layer is the low-impact-weight group. The adjustment strategy is the same within each layer, and different adjustment intensities are used between layers. The hierarchical residual stress adjustment scheme records the hierarchical classification, adjustment type, and specific adjustment parameters of each rivet collaborative riveting group in the form of an adjustment table. For example, rivet collaborative riveting group G1 has a total impact weight of 2.5 and is classified as a high-impact-weight group, adopting a priority adjustment strategy, with a riveting force reduced from 15 kN to 13 kN and a riveting sequence advanced from the 3rd to the 1st. This step realizes the overall optimization of system performance through the differential adjustment strategy of hierarchical classification.

[0054] The differential fine adjustment is implemented on each rivet cooperative press riveting group based on the hierarchical residual stress adjustment scheme. The adjustment range of the fine adjustment is controlled within ±5% of the standard parameters, ensuring that the adjustment effect is significant but does not affect the basic connection strength. The stress redistribution algorithm adopts an iterative optimization method: the target stress distribution state is set as uniform stress in each region and not exceeding the safety threshold, and the actual stress distribution is approximated to the target state by gradually adjusting the parameters of each rivet cooperative press riveting group. The setting of the target distribution state is based on the principles of material mechanics and engineering experience, and the ideal distribution of residual stress is that the compressive stress is in the surface layer and the tensile stress is in the internal and the numerical value is balanced. The convergence process uses the least squares method to optimize, and the square sum of the difference between the current stress distribution and the target distribution is calculated, and the difference is minimized by adjusting the press riveting parameters. The stability of the interfacial electrochemical equilibrium state is achieved by the constraint condition: during the stress adjustment process, the interfacial pressure is ensured to be not less than the minimum value required to maintain the electrochemical equilibrium. The stability monitoring uses real-time potential difference measurement, and when the potential difference exceeds the safety threshold, the stress adjustment is stopped immediately and returned to the safe state. The global optimization adjustment parameters include the complete parameter set of the final press riveting force, press riveting speed, pressure holding time and press riveting sequence of each rivet cooperative press riveting group. The convergence criterion of the optimization process is that the stress distribution changes less than 1% and the electrochemical stability index changes less than 0.02 for three consecutive iterations. For example, after 5 iterations of optimization, the standard deviation of the overall residual stress distribution is reduced from 45 MPa to 28 MPa, and the electrochemical stability index of all regions is greater than 0.65, meeting the convergence condition. This step realizes the optimization of system performance under multi-physical field constraints through fine parameter adjustment and algorithm optimization.

[0055] The control state updating process applies the global optimization adjustment parameters to the actual control system of each rivet collaborative press riveting group. The updating operation transmits the new parameter values to the corresponding riveting equipment controller through the industrial control network, including the complete control instructions such as the press riveting force setting value, the motion speed curve, and the timing arrangement. The multivariable convergence criterion is used to verify that the system reaches a stable equilibrium state, and the criterion includes four aspects: the residual stress convergence, the electrochemical stability, the dynamic response stability, and the parameter consistency. The residual stress convergence requires that the stress value change rate of each measurement point is less than 1 MPa per minute; the electrochemical stability requires that the potential difference of all dissimilar material interfaces is maintained within a safe range; the dynamic response stability is evaluated by monitoring the response characteristics of the system to a small disturbance, and the response time should be less than 100 milliseconds and there should be no oscillation phenomenon; and the parameter consistency requires that the deviation of the actual execution parameters of each rivet collaborative press riveting group from the set parameters is less than 2%. The system stability verification is achieved by continuously monitoring the satisfaction of all criteria within 30 minutes, and when all criteria meet the requirements within the monitoring period, it is confirmed that the system reaches equilibrium. The system equilibrium control state refers to the stable operation state of the multi-rivet synchronous riveting system after global optimization, in which the residual stress distribution is uniform, the electrochemical environment is stable, each group collaborates, and the system response is stable. The record of the equilibrium state includes the final parameter configuration, the system response characteristics, and the long-term stability evaluation results. This step ensures the reliability and persistence of the optimization effect through multidimensional stability verification, and realizes the overall stable control of the multi-rivet synchronous riveting system.

[0056] The control method for multi-rivet synchronous riveting in the embodiment of the application is described above, and the control device for multi-rivet synchronous riveting in the embodiment of the application is described below. Please refer to Figure 2 An embodiment of the control device for multi-rivet synchronous riveting in the embodiment of the application includes: A rivet grouping control module 101 is configured to calculate the rivet interaction strength according to the rivet position parameters and the material parameters, functionally group the plurality of rivets, and obtain a rivet collaborative press riveting group. A timing cascade control module 102 is configured to calculate the stress wave propagation delay time according to the spatial distribution of the rivet collaborative press riveting group, generate a timing cascade control instruction, and obtain a plurality of collaborative control sequences. A stress wave collaborative control module 103 is configured to perform cascade press riveting based on the plurality of collaborative control sequences, monitor the stress wave superposition effect in real time and predict the stress concentration position, dynamically modulate the press riveting parameters for the predicted stress concentration area, and obtain a stress wave collaborative control state. An electrochemical equilibrium control module 104 is configured to monitor the change of the electrochemical potential difference of the dissimilar material interface according to the stress wave collaborative control state, predict the electrochemical instability risk, and perform interface pressure self-adaptive adjustment on the high-risk area, and obtain an interface electrochemical equilibrium state. The global optimization control module 105 is configured to perform global residual stress optimization adjustment on each rivet cooperative rivet group according to the stress wave cooperative control state and the interface electrochemical equilibrium state, and obtain a system balance control state.

[0057] Figure 3 is a structural schematic diagram of a multi-riveting synchronous riveting control device provided by an embodiment of the present application. The multi-riveting synchronous riveting control device 200 can have great differences due to different configurations or performances, and can include one or more processors 210 (for example, one or more processors) and a memory 220, one or more storage media 230 (for example, one or more mass storage device ends) storing application programs 233 or data 232. The memory 220 and the storage media 230 can be temporary storage or persistent storage. The programs stored in the storage media 230 can include one or more modules (not shown in the figure), and each module can include a series of instruction operations in the multi-riveting synchronous riveting control device 200. Further, the processor 210 can be configured to communicate with the storage media 230 and execute the series of instruction operations in the storage media 230 on the multi-riveting synchronous riveting control device 200 to realize the steps of the multi-riveting synchronous riveting control method described above.

[0058] The multi-riveting synchronous riveting control device 200 can also include one or more power supplies 240, one or more wired or wireless network interfaces 250, one or more input / output interfaces 260, and / or one or more operating systems 231, such as Windows Serve, Mac OS X, Unix, Linux, FreeBSD, and the like. Those skilled in the art can understand that the multi-riveting synchronous riveting control device 200 can also include other components, and the details are not described herein. Figure 3 The structure of the multi-riveting synchronous riveting control device shown in the figure does not constitute a limitation on the multi-riveting synchronous riveting control device provided by the present application, and can include more or fewer components than shown, or combine certain components, or different component arrangements.

[0059] The above description is only preferred embodiments of the present application, and does not limit the patent scope of the present application. Any equivalent structural transformation made according to the content of the present application specification and drawings, or direct / indirect application in other related technical fields is included in the patent protection scope of the present application.

Claims

1. A control method for synchronous riveting of multiple rivets, characterized in that: include: The interaction strength between rivets is calculated based on the rivet position parameters and material parameters, and multiple rivets are functionally grouped to obtain a rivet collaborative riveting group. Calculating the stress wave propagation delay time according to the spatial distribution of the rivet cooperative press riveting group, generating a timing cascade control instruction, and obtaining multiple groups of cooperative control sequences; Cascade riveting is performed based on the multiple sets of coordinated control sequences, stress wave superposition effects are monitored in real time, stress concentration locations are predicted, and riveting parameters are dynamically modulated in the predicted stress concentration areas to obtain a stress wave coordinated control state; Monitoring the electrochemical potential difference change at the interface of the dissimilar materials according to the stress wave coordinated control state, predicting the risk of electrochemical instability and adaptively adjusting the interface pressure in high-risk areas to obtain the electrochemical equilibrium state of the interface; According to the stress wave coordinated control state and the interface electrochemical equilibrium state, the global residual stress of each rivet coordinated pressure riveting group is optimized and adjusted to obtain the system equilibrium control state.

2. The control method for synchronous riveting of multiple rivets according to claim 1, characterized in that: The method of calculating the interaction strength between rivets according to the rivet position parameters and material parameters, functionally grouping the multiple rivets to obtain a rivet collaborative pressure riveting group includes: Obtaining the spatial coordinates and connecting line angles of each rivet position, and calculating the mechanical stress propagation strength and electrochemical coupling strength between each rivet based on the spatial coordinates, connecting line angles, electrochemical activity differences at the dissimilar material interface, and workpiece material thickness distribution parameters; Based on the mechanical stress propagation strength and electrochemical coupling strength, a weighted fusion algorithm is used to calculate the comprehensive interaction strength between each rivet pair, identify the dominant path of stress wave propagation and the high-risk channel of electrochemical connectivity, and obtain the interaction strength matrix between rivets; Based on the rivet interaction strength matrix, an inhibition-cooperation relationship network between rivets is constructed, a mutually inhibiting rivet set and a mutually cooperative rivet set are identified, and differentiated weights are assigned to the rivets according to the inhibition-cooperation relationship strength to obtain a weighted grouping strategy; According to the weighted grouping strategy, each rivet is assigned a collaborative priority and a suppression control level, and rivets with collaborative priorities in the same numerical range are classified into the same control group through a priority matching algorithm to obtain a rivet collaborative riveting group.

3. The control method for synchronous riveting of multiple rivets according to claim 2, characterized in that: The method of constructing an inhibition-cooperation relationship network between rivets based on the interaction strength matrix between rivets, identifying mutually inhibiting rivet sets and mutually cooperating rivet sets, and performing differentiated weight allocation on the rivets according to the inhibition-cooperation relationship strength to obtain a weighted grouping strategy includes: According to the intensity distribution of the interaction intensity matrix between rivets, an inhibition relationship threshold and a cooperation relationship threshold are set, and rivet pairs exceeding the cooperation relationship threshold are marked as cooperation node pairs, and rivet pairs exceeding the inhibition relationship threshold and having a negative interaction value are marked as inhibition node pairs, thereby obtaining a rivet relationship network topology structure; Based on the rivet relationship network topology, the network connectivity and centrality index of each rivet are analyzed, core collaborative rivets with multiple collaborative connections and key inhibitory rivets with multiple inhibitory connections are identified, and the influence propagation coefficient of each rivet in the network is calculated to obtain the rivet network influence distribution data; According to the rivet network influence distribution data, a basic weight value is assigned to each rivet, a collaborative enhancement weight is given to the core collaborative rivet, and an inhibitory control weight is given to the key inhibitory rivet. The differentiated weight coefficient of each rivet is generated through the weight normalization algorithm to obtain a weighted grouping strategy.

4. The control method for synchronous riveting of multiple rivets according to claim 1, characterized in that: The stress wave propagation delay time is calculated according to the spatial distribution of the rivet cooperative pressure riveting group, and a timing cascade control instruction is generated to obtain multiple groups of cooperative control sequences, including: Calculating the propagation paths and propagation velocities of stress waves between the groups based on the spatial distribution of the rivet cooperative riveting groups and the anisotropic parameters of the workpiece material, optimizing the paths for different propagation directions based on the propagation paths and propagation velocities, and obtaining a stress wave propagation path diagram between the groups; Calculating the arrival time and amplitude attenuation of the stress wave on each propagation path based on the inter-group stress wave propagation path diagram and the expected values ​​of the press riveting force of each rivet collaborative press riveting group, and correcting the propagation delay time based on the change in the dynamic stiffness of the material to obtain corrected propagation delay time data; A multi-layer cascade trigger strategy is constructed based on the corrected propagation delay time data, cascade priorities and trigger time windows are assigned to each rivet collaborative press riveting group, and startup control instructions and collaborative control instructions for each group are generated according to the arrival timing of the stress wave to obtain a hierarchical cascade control instruction set; The timing of each rivet cooperative riveting group is arranged according to the hierarchical cascade control instruction set, and the start control instruction and the cooperative control instruction are sorted according to the cascade priority combination to obtain multiple groups of cooperative control sequences.

5. The control method for synchronous riveting of multiple rivets according to claim 1, characterized in that: The method of performing cascade riveting based on the multiple sets of coordinated control sequences, monitoring the stress wave superposition effect in real time and predicting the stress concentration location, and dynamically modulating the riveting parameters of the predicted stress concentration area to obtain the stress wave coordinated control state includes: Initiate the cascade riveting process of each rivet collaborative riveting group according to the multiple groups of coordinated control sequences, obtain the stress wave amplitude and frequency characteristics during the riveting execution of each group, identify the propagation direction and superposition area of ​​the stress wave, and obtain real-time stress wave distribution data; Analyzing the superposition pattern of multi-source stress waves based on the real-time stress wave distribution data, identifying constructive superposition areas and destructive superposition areas, calculating the stress concentration degree and evolution trend of each superposition area, and obtaining stress wave superposition effect analysis results; Based on the stress wave superposition effect analysis results and the process status of the cascade riveting, the stress concentration position and concentration intensity at the next moment are predicted by the stress propagation trajectory extrapolation algorithm, and the high-risk stress concentration areas that require intervention and modulation are identified to obtain stress concentration prediction data; Dynamically degrading the riveting force and adaptively adjusting the riveting speed of rivets in high-risk stress concentration areas based on the stress concentration prediction data, and simultaneously performing compensatory parameter enhancement on rivets in adjacent areas to obtain a dynamic modulation parameter configuration; The control instructions of each rivet cooperative riveting group are updated according to the dynamic modulation parameter configuration, and the modulated riveting parameters are applied to the subsequent cascade riveting process to obtain the stress wave cooperative control state.

6. The control method for synchronous riveting of multiple rivets according to claim 5, characterized in that: Based on the stress wave superposition effect analysis results and the process status of the cascade riveting, the stress concentration position and concentration intensity at the next moment are predicted by the stress propagation trajectory extrapolation algorithm, and the high-risk stress concentration area requiring intervention modulation is identified to obtain stress concentration prediction data, including: According to the stress concentration degree and evolution trend in the stress wave superposition effect analysis results, the position coordinates, strength change rate and propagation direction vector of each stress concentration point are extracted, the motion trajectory equation and strength attenuation equation of the stress concentration point are established, and the stress propagation trajectory parameters are obtained; Based on the stress propagation trajectory parameters and the process state of the cascade riveting, the displacement and strength change of each stress concentration point in the next riveting time step are calculated by a trajectory extrapolation algorithm, the appearance position and initial strength of the newly generated stress concentration point are predicted, and the stress concentration state prediction result is obtained; A high-risk stress concentration threshold is set according to the stress concentration state prediction result, and stress concentration areas with predicted strength exceeding the threshold are marked as high-risk areas. The high-risk areas are prioritized according to the risk level to obtain stress concentration prediction data.

7. The control method for synchronous riveting of multiple rivets according to claim 1, characterized in that: The method of monitoring the electrochemical potential difference change at the interface of different materials according to the stress wave coordinated control state, predicting the risk of electrochemical instability and adaptively adjusting the interface pressure in high-risk areas to obtain the electrochemical equilibrium state of the interface includes: According to the stress distribution data in the stress wave coordinated control state and the type of the dissimilar material interface at each rivet position, real-time change data of the electrochemical potential difference in each dissimilar material interface region is obtained, and the interface region where the electrochemical potential difference gradient exceeds the threshold is identified to obtain an electrochemical potential difference distribution map; Based on the electrochemical potential difference distribution map, the electrochemical connection paths between adjacent rivets are analyzed to identify high-risk connection areas and electrochemical potential difference amplification areas that form galvanic corrosion loops, and the corrosion current density and diffusion rate of each connection area are calculated to obtain electrochemical instability risk assessment data. Based on the corrosion current density and diffusion rate in the electrochemical instability risk assessment data, an electrochemical kinetic algorithm is used to predict the instability time and degree of each high-risk connected area, identify critical instability areas requiring emergency intervention, and obtain an electrochemical instability prediction result; Based on the electrochemical instability prediction results, the interface pressure of the rivet in the critical instability region is enhanced and regulated, and the pressure gradient in the electrochemical potential difference amplification region is optimized and regulated to obtain a differentiated interface pressure regulation strategy; The pressure states of the interface regions of the different materials are updated according to the differentiated interface pressure regulation strategy, and high-risk electrochemical connection paths are cut off through pressure redistribution to obtain an electrochemical equilibrium state of the interface.

8. The control method for synchronous riveting of multiple rivets according to claim 1, characterized in that: The method of optimizing and adjusting the global residual stress of each rivet cooperative riveting group according to the stress wave cooperative control state and the interface electrochemical equilibrium state to obtain the system equilibrium control state includes: Based on the stress wave coordinated control state and the interface electrochemical equilibrium state, the comprehensive stress state and electrochemical stability index of each rivet position are calculated using a multi-physics field information fusion algorithm to generate a residual stress distribution map and an electrochemical stability distribution map of the entire workpiece, thereby obtaining comprehensive system status evaluation data; Based on the comprehensive evaluation data of the system status, the residual stress exceeding the standard area and the electrochemical unstable area are identified, the influence weight and transfer coefficient of each area on the adjacent rivet collaborative press riveting group are calculated, the mutual influence relationship matrix between the rivet collaborative press riveting groups is constructed, and the results of the inter-group coupling influence analysis are obtained; A hierarchical optimization strategy is formulated based on the results of the inter-group coupling influence analysis, priority adjustment is performed on the rivet collaborative press riveting group with high influence weight, and collaborative compensation adjustment is performed on the rivet collaborative press riveting group with low influence weight, so as to obtain a hierarchical residual stress adjustment scheme; Based on the hierarchical residual stress adjustment scheme, each rivet cooperative press riveting group is differentially fine-tuned, and the residual stress is converged to the target distribution state through the stress redistribution algorithm, while maintaining the stability of the electrochemical equilibrium state of the interface, thereby obtaining the global optimized adjustment parameters; The control state of each rivet collaborative riveting group is updated according to the global optimization adjustment parameters, and the system stability and balance are verified through a multivariable convergence criterion to obtain the system balance control state.

9. A control device for synchronous riveting of multiple rivets, characterized in that: The control device for synchronous riveting of multiple rivets includes: A rivet grouping control module is used to calculate the interaction strength between rivets based on rivet position parameters and material parameters, and functionally group multiple rivets to obtain a rivet collaborative pressure riveting group; A timing cascade control module is used to calculate the stress wave propagation delay time according to the spatial distribution of the rivet cooperative pressure riveting group, generate timing cascade control instructions, and obtain multiple groups of cooperative control sequences; A stress wave collaborative control module is used to perform cascade riveting based on the multiple sets of collaborative control sequences, monitor the stress wave superposition effect in real time and predict the stress concentration location, dynamically modulate the riveting parameters in the predicted stress concentration area, and obtain a stress wave collaborative control state; an electrochemical equilibrium control module for monitoring changes in the electrochemical potential difference at the interface of dissimilar materials based on the stress wave coordinated control state, predicting the risk of electrochemical instability and adaptively adjusting the interface pressure in high-risk areas to obtain an electrochemical equilibrium state of the interface; The global optimization control module is used to optimize and adjust the global residual stress of each rivet cooperative riveting group according to the stress wave cooperative control state and the interface electrochemical equilibrium state to obtain the system equilibrium control state.

10. A control device for synchronous riveting of multiple rivets, characterized in that: The control device for multi-rivet synchronous riveting includes: a memory and at least one processor, wherein the memory stores instructions; The at least one processor calls the instructions in the memory to enable the multi-rivet synchronous riveting control device to perform the steps of the multi-rivet synchronous riveting control method according to any one of claims 1 to 8.

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