Assembly deviation prediction method and device based on ship propulsion system

Abstract

The invention relates to an assembly deviation prediction method and device based on a ship propulsion system. The method comprises the steps that part manufacturing data, actual working conditions and load distribution information of a ship propeller are acquired; constructing an assembly deviation transfer model based on the part manufacturing data; performing simulation through a Monte Carlo method based on the deviation transfer model, and constructing a rigid deviation prediction model; performing flexible assembly deviation analysis on the rigidity deviation prediction model based on a finite element method to obtain flexible deviation data; constructing a rigid-flexible coupling deviation prediction model based on the flexible deviation data and the rigid deviation prediction model; according to the method, prediction is carried out through the rigid-flexible coupling deviation prediction model according to the actual working condition and the load distribution information, the overall assembly deviation of the ship propeller is obtained, accurate prediction of the assembly deviation is achieved by introducing the rigid-flexible coupling deviation prediction model coupling rigid body tolerance analysis and flexible deformation deviation, and then the assembly precision is effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ship manufacturing, in particular to an assembly deviation prediction method and device based on a ship propulsion system. BACKGROUND

[0002] In the field of ship equipment manufacturing, multi-source deviation factors from manufacturing deviation, assembly deviation and structural flexible deformation produce complex interactions, resulting in rigid-flexible coupling transmission characteristics of the final size deviation, which is difficult to establish a reliable prediction model, which has become the main technical bottleneck restricting the optimization of assembly quality. The quality of the deviation transmission model construction directly affects the effectiveness of subsequent precision prediction and process optimization.

[0003] The assembly process deviation of the propeller-shaft system-module has a prominent effect on the final assembly precision of the ship. The ship propeller and shaft system can produce torsion and transverse deformation due to uneven transmission torque during manufacturing and assembly, misalignment during installation, uneven material, inaccurate processing and imbalance of their own quality. The assembly module produces displacement during assembly, and the bending moment is generated due to the holding force and the dead weight, which constitutes the disturbance source in the deviation analysis. Under the influence of manufacturing, assembly deviation and environmental factors, the structure undergoes flexible deformation, making the operation deviate from the standard point, and a large deviation is generated at the end. There is also a coupling influence of non-geometric deviation in the process of part geometric parameter identification, which is an important factor restricting the further improvement of ship precision.

[0004] The existing method follows the rigid body deviation theory, only considers the static deformation analysis of a single flexible body and the simple superposition of a single deviation influence, and the model does not consider the rigid-flexible coupling deviation characteristics under the influence of multiple factors. At present, ship deviation prediction mainly adopts numerical analysis methods such as probability method and extreme value method to analyze the assembly tolerance of the assembly size chain of the assembly body under the assumption of rigid body. Due to the complex and changeable factors affecting the deviation, the source and action mechanism of the flexible deformation and other non-geometric deviation factors caused by the dead weight and load are relatively complex, and it is difficult to improve the accuracy of the deviation prediction model results. SUMMARY

[0005] The main purpose of the present application is to provide an assembly deviation prediction method and device based on a ship propulsion system, which aims to solve the technical problem of low assembly deviation prediction precision of the existing method.

[0006] To achieve the above-mentioned purpose, the present application provides an assembly deviation prediction method based on a ship propulsion system, which comprises: Obtaining the part manufacturing data, actual working condition and load distribution information of the ship propeller; Constructing an assembly deviation transmission model based on the part manufacturing data; simulate based on the bias transmission model by Monte Carlo method, and construct a rigid bias prediction model, which is used to predict the cumulative bias of the propeller composed of multiple rigid parts after assembly is completed; analyze the flexible assembly bias based on the finite element method to obtain flexible bias data; construct a rigid-flexible coupling bias prediction model based on the flexible bias data and the rigid bias prediction model; predict based on the actual working condition and load distribution information by the rigid-flexible coupling bias prediction model to obtain the overall assembly bias of the ship propeller.

[0007] In an embodiment, the method of constructing an assembly bias transmission model based on the part manufacturing data comprises: perform feature decomposition based on the part manufacturing data to obtain feature vectors of multiple parts; construct non-ideal surfaces based on the feature vectors of the parts, which are used to simulate the actual surface bias of the parts generated in the manufacturing process; construct part real geometry models based on the non-ideal surfaces and part ideal geometry models; obtain part assembly sequences and positioning references, and determine manufacturing bias and installation bias based on the part real geometry models, the part assembly sequences, and the positioning references; determine bias transmission relationships based on the manufacturing bias and the installation bias; construct an assembly bias transmission model based on the bias transmission relationships, which is used to simulate the transmission and accumulation of the bias of each part in the assembly process.

[0008] In an embodiment, the method of constructing a rigid bias prediction model based on the bias transmission model by Monte Carlo method comprises: set the number of simulations and the parameter range, and randomly generate manufacturing bias and installation bias of each part in each simulation based on the bias transmission model; simulate the assembly process by Monte Carlo method according to the manufacturing bias and the installation bias, and calculate the cumulative bias of the propeller in each simulation; statistically analyze the cumulative bias of the propeller in each simulation to obtain the rigid bias distribution of the propeller under different combinations of manufacturing bias and installation bias; randomly sample bias sources and perform bias analysis based on the rigid bias distribution by using a random number generator to obtain assembly bias samples; calculate assembly bias evaluation indexes based on the assembly bias samples, wherein the assembly bias evaluation indexes are determined according to the statistical characteristics of the assembly bias; define a deviation transmission chain, construct a rigid deviation prediction model based on the deviation transmission chain, the rigid deviation distribution and an assembly deviation evaluation index.

[0009] In an embodiment, the cumulative deviation of the thruster in each simulation is calculated by simulating the assembly process according to the manufacturing deviation and the installation deviation through the Monte Carlo method, including: According to the manufacturing deviation and the installation deviation, the displacement rotation of the deviation source in the assembly process is calculated; A sensitivity matrix is constructed, which is used to represent the influence degree / contribution coefficient of each deviation source on the cumulative deviation of the thruster; According to the displacement rotation and the sensitivity matrix, the cumulative deviation of each part or feature in the thruster is determined; According to the cumulative deviation of each part or feature in the thruster, the cumulative deviation of the thruster in each simulation is calculated.

[0010] In an embodiment, the flexible assembly deviation analysis is performed on the rigid deviation prediction model based on the finite element method to obtain flexible deviation data, including: The finite element simulation is performed on the rigid deviation prediction model to simulate the flexible deformation and stress distribution of the thruster in the working state by applying the part self-weight and external load, and the finite element simulation result is obtained; Based on the finite element simulation result, the deformation data of the measurement key points is determined; Based on the deformation data of the measurement key points, the part stiffness matrix is calculated; Based on the part stiffness matrix and the finite element simulation result, the deviation of each part under the flexible deformation is determined to obtain the flexible deviation data.

[0011] In an embodiment, the part stiffness matrix is calculated based on the deformation data of the measurement key points, including: Based on the deformation data of the measurement key points, the key feature points are determined, wherein the deviation source affecting the assembly quality exists at the key feature points; A unit force opposite to the deviation direction is applied on the finite element node corresponding to the key feature point to obtain a displacement response; A displacement response vector of each key feature point is constructed according to the displacement response and the unit force; A displacement response matrix is generated based on the displacement response vectors of the key feature points; A flexibility matrix of the part is determined based on the displacement response matrix; The part stiffness matrix is determined based on the flexibility matrix of the part.

[0012] In an embodiment, the rigid-flexible coupling deviation prediction model is constructed based on the flexible deviation data and the rigid deviation prediction model, including: convert the flexible deviation data into a displacement field form to obtain node displacement data; perform deviation analysis according to the node displacement data and the rigid deviation prediction model to obtain a rigid-flexible coupling deviation distribution; simulate the influence of different loads on the deviation under actual working conditions based on the rigid-flexible coupling deviation distribution to obtain a deviation mapping relationship in the rigid-flexible coupling deviation prediction model; construct the rigid-flexible coupling deviation prediction model based on the deviation mapping relationship.

[0013] In addition, to achieve the above-mentioned purpose, the application further provides a ship propulsion system-based assembly deviation prediction device, which comprises: an acquisition module, configured to acquire part manufacturing data, actual working conditions and load distribution information of a ship propeller; a construction module, configured to construct an assembly deviation transmission model based on the part manufacturing data; a simulation module, configured to simulate based on the deviation transmission model by a Monte Carlo method, and construct a rigid deviation prediction model, which is used to predict the cumulative deviation of the propeller composed of multiple rigid parts after assembly is completed; an analysis module, configured to perform flexible assembly deviation analysis on the rigid deviation prediction model based on a finite element method to obtain flexible deviation data; the construction module is further configured to construct a rigid-flexible coupling deviation prediction model based on the flexible deviation data and the rigid deviation prediction model; a prediction module, configured to predict by the rigid-flexible coupling deviation prediction model according to the actual working conditions and load distribution information to obtain the overall assembly deviation of the ship propeller.

[0014] In addition, to achieve the above-mentioned purpose, the application further provides a ship propeller, which is applied to the ship propulsion system-based assembly deviation prediction method as described above.

[0015] In addition, to achieve the above-mentioned purpose, the application further provides a storage medium, which is a computer-readable storage medium, and a computer program is stored on the storage medium, and the computer program is executed by a processor to implement the steps of the ship propulsion system-based assembly deviation prediction method as described above.

[0016] In addition, to achieve the above-mentioned purpose, the application further provides a computer program product, which comprises a computer program, and the computer program is executed by a processor to implement the steps of the ship propulsion system-based assembly deviation prediction method as described above.

[0017] One or more technical solutions provided in the application acquire manufacturing data, actual working conditions and load distribution information of parts of a ship propeller; an assembly deviation transmission model is constructed based on the manufacturing data; a rigid deviation prediction model is constructed by simulating the model through a Monte Carlo method, and the rigid deviation prediction model is used to predict accumulated deviations of the propeller composed of multiple rigid parts after assembly is completed; flexible assembly deviation analysis is performed on the rigid deviation prediction model based on a finite element method to obtain flexible deviation data; a rigid-flexible coupling deviation prediction model is constructed based on the flexible deviation data and the rigid deviation prediction model; and overall assembly deviations of the ship propeller are obtained through the rigid-flexible coupling deviation prediction model according to the actual working conditions and load distribution information. The rigid-flexible coupling deviation prediction model coupling rigid tolerance analysis and flexible deformation deviation is introduced, accurate prediction of assembly deviations is realized, and assembly precision is effectively improved. BRIEF DESCRIPTION OF DRAWINGS

[0018] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the application and serve to explain the principles of the application together with the specification.

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, brief introductions to the drawings needed in the embodiments or prior art descriptions will be given below. Obviously, for those skilled in the art, other drawings can also be obtained based on these drawings without creative labor.

[0020] Figure 1 A flowchart provided by the first embodiment of the ship propeller assembly deviation prediction method based on a ship propeller system is provided. Figure 2 A schematic diagram of a ship propeller-shaft system-modular assembly is provided for the first embodiment of the ship propeller assembly deviation prediction method based on a ship propeller system. Figure 3 A schematic diagram of components in a ship propeller-shaft system-modular assembly is provided for the first embodiment of the ship propeller assembly deviation prediction method based on a ship propeller system. Figure 4 A schematic diagram of flexible deformation deviations of key points of parts in a ship propeller-shaft system-modular assembly under the action of clamping force, connecting force and self-gravity during assembly is provided for the first embodiment of the ship propeller assembly deviation prediction method based on a ship propeller system. Figure 5 A diagram of the relationship between axial displacement offset and maximum stress is provided for the first embodiment of the ship propeller assembly deviation prediction method based on a ship propeller system. Figure 6The axis angle offset and maximum stress relationship diagram provided by the embodiment of the ship propulsion system assembly deviation prediction method of the application; Figure 7 The flowchart provided by the second embodiment of the ship propulsion system assembly deviation prediction method of the application; Figure 8 The flowchart provided by the third embodiment of the ship propulsion system assembly deviation prediction method of the application; Figure 9 The overall flowchart of the rigid-flexible coupling deviation prediction model construction provided by the first embodiment of the ship propulsion system assembly deviation prediction method of the application; Figure 10 The detailed flowchart of the assembly deviation prediction provided by the first embodiment of the ship propulsion system assembly deviation prediction method of the application.

[0021] Explanation of reference numerals: The propeller 1, the shafting compensation device 2, the stern shaft sealing device 3, the thrust bearing 4, the intermediate shaft 5 gear reduction box 6, the hull module 7, the power device 8, the propeller sealing device 9, the stern shaft 10 and the hatch valve 11.

[0022] The purpose implementation, functional characteristics and advantages of the application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0023] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the application, and are not used to limit the application.

[0024] In order to better understand the technical solutions of the application, the specific embodiments will be described in detail below with reference to the drawings and the specific embodiments.

[0025] The main solution of the embodiment of the application is: obtaining the part manufacturing data, actual working condition and load distribution information of the ship propeller; constructing an assembly deviation transmission model based on the part manufacturing data; simulating by Monte Carlo method based on the deviation transmission model, constructing a rigid deviation prediction model, the rigid deviation prediction model is used to predict the cumulative deviation of the propeller composed of multiple rigid parts after assembly; based on the finite element method, the flexible assembly deviation analysis is carried out on the rigid deviation prediction model, and the flexible deviation data is obtained; based on the flexible deviation data and the rigid deviation prediction model, a rigid-flexible coupling deviation prediction model is constructed; the overall assembly deviation of the ship propeller is obtained by predicting the actual working condition and load distribution information through the rigid-flexible coupling deviation prediction model.

[0026] The existing method follows the rigid body deviation theory, only considers the static deformation analysis of a single flexible body and the simple superposition of a single deviation influence, and the model does not consider the deviation characteristics of rigid-flexible coupling under the influence of multiple factors. At present, ship deviation prediction mainly uses numerical analysis methods such as probability method and extreme value method to analyze the tolerance of the assembly size chain of the assembly body under the assumption of rigid body. Due to the complex and changeable factors affecting the deviation, the sources and action mechanisms of non-geometric deviation factors such as flexible deformation caused by self-weight and load are relatively complex, and it is difficult to improve the accuracy of the deviation prediction model results.

[0027] The present application provides a solution, which realizes accurate prediction of assembly deviation by introducing a rigid-flexible coupling deviation prediction model coupling rigid body tolerance analysis and flexible deformation deviation, thereby effectively improving the assembly precision.

[0028] It should be noted that the execution subject of the present embodiment can be a computing service device with data processing, network communication and program running functions, such as a tablet computer, a personal computer, a mobile phone, etc., or an electronic device capable of realizing the above functions, a ship propeller, etc. In the following, the present embodiment and each of the following embodiments will be described taking the ship propeller as an example.

[0029] Based on this, the present embodiment provides an assembly deviation prediction method based on a ship propulsion system, which refers to Figure 1 , Figure 1 The present embodiment provides an assembly deviation prediction method based on a ship propulsion system.

[0030] In the present embodiment, the assembly deviation prediction method based on the ship propulsion system comprises steps S10-S60: Step S10: Obtain the manufacturing data of the parts of the ship propeller, the actual working condition and the load distribution information.

[0031] It should be noted that the ship propeller is an important component of the ship, which is used to generate thrust to drive the ship forward. The propeller generally converts the mechanical energy of rotation into the kinetic energy of water flow through the blades, thereby pushing the ship. In the present embodiment, the assembly of the ship propeller is carried out in a modular manner, i.e. an entire assembly module of the propeller and the shafting connected thereto, wherein the shafting refers to a transmission system connecting the engine (or main engine) of the ship and the propeller, mainly including main shaft, bearing, coupling and other components, which transmits the power of the engine to the propeller to realize the propelling effect. The present embodiment takes the modular assembly of the cabin valve power system-intermediate shaft-stern shaft-propeller and pressure-resistant shell as an example, considers the manufacturing and assembly deviation and the flexible deformation influence caused by the self-weight, assembly stress and load of the parts, and then carries out assembly prediction, which can effectively improve the actual precision of assembly deviation prediction.

[0032] It can be understood that the part manufacturing data includes but is not limited to detailed information such as size, shape, material, manufacturing process, etc. of each part. The actual working condition refers to the environmental condition and working state of the ship propeller in the actual operation process, such as water temperature, water flow speed, direction, ship sailing speed, etc. The load distribution information refers to the load condition of each part of the ship propeller during operation.

[0033] Step S20: constructing an assembly deviation transmission model based on the part manufacturing data.

[0034] It should be noted that the assembly deviation transmission model is a mathematical model for describing the deviation transmission law of the parts of the ship propeller in the assembly process. The model can consider the influence of factors such as the geometric relationship between parts, material properties, assembly process, etc. on the assembly deviation, so as to realize accurate prediction of the assembly deviation. When constructing the assembly deviation transmission model, the manufacturing accuracy of the parts, the assembly sequence, the assembly constraint conditions, etc. need to be fully considered to ensure the accuracy and reliability of the model.

[0035] In a feasible implementation, step S20 can include: performing feature decomposition based on the part manufacturing data to obtain feature vectors of multiple parts; constructing non-ideal surfaces based on the feature vectors of the parts, the non-ideal surfaces being used to simulate actual surface deviations of the parts generated in the manufacturing process; constructing a real geometry model of the parts based on the non-ideal surfaces and the ideal geometry model of the parts; obtaining a part assembly sequence and a positioning reference, determining manufacturing deviations and installation deviations based on the real geometry model of the parts, the part assembly sequence, and the positioning reference; determining a deviation transmission relationship based on the manufacturing deviations and the installation deviations; constructing an assembly deviation transmission model based on the deviation transmission relationship, the assembly deviation transmission model being used to simulate the transmission and accumulation of the deviations of the parts in the assembly process.

[0036] It should be noted that feature decomposition refers to decomposing the features such as geometry and size of the parts, so as to more accurately describe and analyze the deviation of the parts in the manufacturing and assembly process. Through feature decomposition, feature vectors of the parts can be obtained, which reflect the size and shape changes of the parts in different directions.

[0037] It can be understood that based on the feature vectors of the parts, non-ideal surfaces can be constructed. The non-ideal surface refers to the surface of the part that has a certain deviation from the ideal geometry due to various factors (such as machining error, material deformation, etc.) in the actual manufacturing process. By simulating these actual surface deviations, the actual situation of the parts in the manufacturing process can be more truly reflected.

[0038] Further, by combining the ideal geometric model of the part and the non-ideal surface, a real geometric model of the part can be constructed. This real geometric model contains not only the ideal shape and size information of the part, but also the actual shape and size variation information caused by manufacturing deviations.

[0039] After obtaining the real geometric model of the part, the assembly sequence and positioning reference of the part also need to be considered. The assembly sequence refers to the process of assembling parts in a certain order during assembly, while the positioning reference is a reference for determining the relative position and direction of parts during assembly. By considering these factors, the transmission and accumulation of manufacturing deviations and installation deviations during assembly can be determined.

[0040] Based on the above information, the deviation transmission relationship can be determined. The deviation transmission relationship refers to the rule of deviation transmission from one part to another during assembly. This rule can be described and analyzed by a mathematical model.

[0041] Finally, based on the deviation transmission relationship, an assembly deviation transmission model is constructed. The assembly deviation transmission model can simulate the transmission and accumulation of deviations of each part during assembly, thereby achieving accurate prediction of assembly deviations.

[0042] Step S30: Based on the deviation transmission model, a Monte Carlo method is used for simulation to construct a rigid deviation prediction model, which is used to predict the cumulative deviation of the thruster composed of multiple rigid parts after assembly is completed.

[0043] It should be noted that the Monte Carlo method is a numerical calculation method based on probability statistics, which simulates a large number of random events to approximately solve complex problems. In this embodiment, the Monte Carlo method is used to simulate the assembly deviation transmission model, which can simulate the deviation transmission and accumulation of multiple rigid parts during assembly.

[0044] Specifically, a large number of random samples are generated, which are substituted into the assembly deviation transmission model to calculate the assembly deviation corresponding to each sample, and then statistical analysis is performed on these deviations to obtain a rigid deviation prediction model. This model can predict the cumulative deviation of the thruster composed of multiple rigid parts after assembly is completed.

[0045] Step S40: Based on the finite element method, flexible assembly deviation analysis is performed on the rigid deviation prediction model to obtain flexible deviation data.

[0046] It should be noted that the finite element method is a numerical analysis method that solves complex physical problems by discretizing them into a series of simple unit problems. In this embodiment, the finite element method is used to analyze the flexible assembly deviation of the rigid deviation prediction model, which can simulate the flexible deformation of the propeller during assembly due to the weight of the parts, assembly stress and load, etc.

[0047] Specifically, the rigid deviation prediction model is imported into the finite element analysis software, the corresponding boundary conditions and loads are set, and then the simulation calculation is performed. Through simulation calculation, the stress distribution and deformation of the propeller during assembly can be obtained, and the simulation results can be analyzed and processed to extract the flexible deviation data. The flexible deviation data reflects the flexible deformation of the propeller during assembly due to factors such as the weight of the parts, assembly stress and load, and is an important basis for subsequent construction of the rigid-flexible coupling deviation prediction model.

[0048] Step S50: constructing a rigid-flexible coupling deviation prediction model based on the flexible deviation data and the rigid deviation prediction model.

[0049] It should be noted that based on the flexible deviation data and the rigid deviation prediction model, a rigid-flexible coupling deviation prediction model can be constructed, which not only considers the deviation transmission and accumulation between rigid parts, but also considers the assembly deviation caused by flexible deformation, so as to more accurately predict the overall assembly deviation of the ship propeller.

[0050] It can be understood that when constructing the rigid-flexible coupling deviation prediction model, the flexible deviation data and the rigid deviation prediction model need to be fused, which involves integrating the flexible deformation obtained by finite element analysis with the rigid deviation prediction results obtained based on the Monte Carlo method to form a prediction model that comprehensively considers rigid deviation and flexible deformation. Through advanced mathematical models and algorithms, the two sources of deviation are coupled and analyzed, so as to more accurately reflect the complex deviation transmission and accumulation mechanism in the actual assembly process.

[0051] It is worth noting that by comprehensively and effectively representing and analyzing the rigid-flexible coupling influencing factors, the flexible deformation deviation obtained by finite element simulation is introduced into the deviation analysis process, the rigid body tolerance analysis and flexible deformation deviation coupling are realized, and the rigid-flexible coupling deviation prediction model can more comprehensively reflect the actual deformation in the assembly process. The ship propeller-shaft system-module assembly deviation predicted by the rigid-flexible coupling deviation prediction model improves the prediction accuracy and provides a quantitative basis for assembly scheme optimization.

[0052] In a specific implementation, a model bias transfer relationship and a typical rigid component and flexible component division are defined, in which the shafting, the intermediate shaft, the stern shaft, and the hull module are flexible bias analysis objects, and bias distribution parameters are set, and then the flexible assembly bias of the shafting, the intermediate shaft, the stern shaft, and the hull module and the like is analyzed by using the finite element analysis software. By simulating the deformation and displacement of these components in the assembly process, flexible bias data is obtained. The flexible bias data includes assembly bias caused by component deformation, which is crucial for accurately predicting the overall assembly accuracy. In the flexible assembly bias analysis, special attention is paid to the deformation of key components such as the shafting, the intermediate shaft, and the stern shaft. These components are easily deformed during assembly due to various forces such as gravity, pretension, assembly force, etc., thereby affecting the assembly accuracy. By finite element analysis, the deformation of these components under stress can be calculated, and then the flexible bias data is obtained. At the same time, considering the complexity of large components such as the hull module, appropriate simplification and assumptions are adopted to reduce the analysis difficulty. For example, the hull module can be simplified as a shell element or a body element with equivalent stiffness and mass, so as to improve the calculation efficiency while ensuring the analysis accuracy. On the basis of obtaining the flexible bias data and the rigid bias prediction model, a rigid-flexible coupling bias prediction model is further constructed. This model takes into account the assembly bias of rigid parts and flexible components, and can more accurately predict the overall assembly accuracy of the ship propeller. Through the rigid-flexible coupling bias prediction model, the overall assembly bias value of the ship propeller can be predicted according to the actual working condition and load distribution information. These prediction results are of great significance for guiding the assembly process, optimizing the assembly process, and improving the assembly accuracy.

[0053] As shown in Figure 2 , Figure 2 is a schematic diagram of ship propeller-shafting-modular assembly, the propeller is assembled with other modules of the ship through the shafting, wherein the shafting is a transmission shafting, the modules include module one and module two, and the module one is composed of a reduction device, a power device, and an import and export pipe system connected with an integrated installation platform.

[0054] As shown in Figure 3 , Figure 3 is a schematic diagram of the structure of each component in the ship propeller-shafting-module assembly, which includes a propeller 1, a shafting compensation device 2, a stern shaft sealing device 3, a thrust bearing 4, an intermediate shaft 5 gear reduction box 6, a hull module 7, a power device 8, a propeller sealing device 9, a stern shaft 10, and a hatch valve 11.

[0055] As shown in Figure 4 , Figure 4The schematic diagram of the flexible deformation deviation of the key points of the parts in the assembly of the ship propeller-shaft module under the action of clamping force, connecting force and self gravity in the assembly process, which includes an ideal assembly model and a rigid-flexible coupling model, wherein the ideal assembly model is based on the rigid body model for assembly deviation prediction, without considering the flexible deformation deviation caused by the self weight, assembly stress and load of the parts, and only considering the positioning displacement of the parts themselves and assembly steps The assembly displacement caused by the positioning coordination deviation The rigid-flexible coupling model comprehensively considers the rigid deviation and flexible deformation deviation, and can more accurately reflect the complex deviation in the actual assembly process. In the rigid-flexible coupling model, the key parts such as the propeller, shaft system, intermediate shaft and the like will produce bending and other flexible deformation deviations under the action of clamping force, connecting force and self gravity in the assembly process, and the assembly deviation displacement and the flexible deviation displacement caused by the gravity and load factors obtained by finite element calculation .

[0056] In a feasible implementation, the step S50 can include: converting the flexible deviation data into a displacement field form to obtain node displacement data; performing deviation analysis according to the node displacement data and the rigid deviation prediction model to obtain a rigid-flexible coupling deviation distribution; simulating the influence of different loads on the deviation under actual working conditions based on the rigid-flexible coupling deviation distribution to obtain a deviation mapping relationship in the rigid-flexible coupling deviation prediction model; and constructing a rigid-flexible coupling deviation prediction model based on the deviation mapping relationship.

[0057] It should be noted that the flexible deviation data is converted into a displacement field form, i.e. the flexible deformation obtained by finite element simulation is derived in the form of a displacement field, so that the displacement of each node can be intuitively represented, i.e. the node displacement data can be obtained, which reflects the displacement change of the propeller in the assembly process due to the flexible deformation. The node displacement data is converted into a matrix file and imported into the 3DCS software, and deviation analysis is performed in combination with the rigid deviation prediction model data.

[0058] It can be understood that in the finite element simulation, a.inp input file containing nodes, elements and material properties is generated by using a pre-processing module, and then the grid file is loaded in the FEA_StiffGen module of 3DCS. The modeling points in the 3DCS assembly model are associated with the nearest nodes in the FEA grid, and these nodes are added to a node set containing node coordinate information, and then the stiffness matrix is solved, and finally three main files are output: node coordinate file, element and material grid information file and stiffness matrix file.

[0059] It is worth noting that the rigid-flexible coupling deviation distribution is obtained by analyzing the influence of load on deviation, and the influence of different loads on the stern end face on the deviation under actual working conditions is simulated to obtain the mathematical relationship between the rigid-flexible coupling deviation prediction model and the deflection. Taking the maximum axial stress on the shafting as the main indicator, the relationship between the axial displacement offset and the maximum stress and the relationship between the axis angle offset and the maximum stress are obtained. Based on these relationships, the deviation mapping relationship in the rigid-flexible coupling deviation prediction model can be obtained.

[0060] As shown in Table 1, Table 1 is the relationship between axial displacement offset and maximum stress, which includes the offset / mm and the corresponding maximum stress / MPa, e.g., the deflection Including 0, 3, 5, 7, 8, etc., the corresponding maximum stress / MPa are 93.08, 94.19, 96.57, 103.9, 108.8 respectively.

[0061] Table 1

[0062] As shown in Table 2, Table 2 is the relationship between axis angle offset and maximum stress, which includes the offset / ° and the corresponding maximum stress / MPa, e.g., the deflection / ° includes 0, 0.5, 0.6, 0.8, etc., and the corresponding maximum stresses / MPa are 93.08, 98.45, 98.88, and 104.5 respectively.

[0063] Table 2

[0064] like Figure 5 As shown, Figure 5 The relationship between axial displacement and maximum stress is shown in the figure, including the offset / ° and the corresponding maximum stress / MPa, e.g., the deflection / ° includes 0, 0.5, 0.6, 0.8, etc., and the corresponding maximum stress / MPa are 93.08, 98.45, 98.88, 104.5, etc. There is a nearly linear relationship between the maximum stress growth and the shafting offset.

[0065] like Figure 6 As shown, Figure 6 The relationship between the axis angle offset and the maximum stress is shown in the figure, including the offset / ° and the corresponding maximum stress / MPa, e.g., the deflection / ° including 0, 0.5, 0.6, 0.8, etc. The corresponding maximum stress / MPa is 93.08, 98.45, 98.88, 104.5, respectively. There is also a nearly linear relationship between the maximum stress growth and the angle offset of the axis.

[0066] It is worth noting that the flexible deviation is integrated into the rigid model to establish a rigid-flexible coupling system deviation prediction model. The output node, element, material grid information file, stiffness matrix file and mass matrix file are imported into the flexible initialization assembly module, the stiffness matrix, grid and parts are linked, and the deformation caused by the model calculation is updated, the corresponding parts are loaded, the comprehensive deviation result of the radial offset deviation analysis of the stern shaft end surface after assembly is obtained through joint analysis, and the calculation formula is:

[0067] is the total deviation vector at a certain measurement point or key feature, is the rigid deviation component, is the flexible deformation deviation component, is the cumulative value of the rigid deviation prediction model, is the force vector acting on the assembly, including load value and gravity, is the system flexibility matrix, which is determined by the displacement response value obtained by applying a unit load to the flexible part finite element analysis (FEA).

[0068] Step S60: predicting by the rigid-flexible coupling deviation prediction model according to the actual working condition and load distribution information to obtain the overall assembly deviation of the ship propeller.

[0069] It should be noted that the assembly deviation is predicted based on different actual working conditions and load distribution, which more effectively couples the geometric deviation and flexible deformation deviation of assembly. It can be understood that through the rigid-flexible coupling deviation prediction model, various deviation sources of the ship propeller during the assembly process can be considered comprehensively, including the deviation transmission and accumulation between rigid parts, and the assembly deviation caused by flexible deformation. The rigid-flexible coupling deviation prediction model cooperatively uses finite element simulation and Monte Carlo method analysis, takes the working condition and load distribution as the model input, predicts the assembly deviation through the rigid-flexible coupling deviation prediction model, thereby improves the assembly precision, effectively couples the geometric deviation and flexible deformation deviation of assembly, and realizes the accurate prediction and optimization of the assembly deviation of the ship propeller-shaft system-module.

[0070] In a specific implementation, the deviation transmission chain from the hatch valve-power device-intermediate shaft-stern shaft-propeller is calculated, and the stern end surface axial offset deviation of the stern shaft is taken as an example for illustration. The axial offset from the stern end surface of the stern shaft to the end of the power shaft is taken as a closed loop Z,​ For the corner deviation, each component ring is: (1) The axial machining deviation of the stern shaft propeller mounting surface is z1, and the offset of the stern shaft end caused by the flexible deviation is , the component ring ; 3600 is the length of the stern shaft.

[0071] (2) The axial length dimension manufacturing deviation of the stern shaft is z3, and the offset of the intermediate shaft end caused by the flexible deviation is , the component ring ; 1000 is the length of the intermediate shaft.

[0072] (3) The deviation of the base point mark of the pontoon is z5, and the offset of the power shaft end of the gear reducer module caused by the flexible deviation is , the component ring ; 1000 is the length of the power shaft of the gear reducer module.

[0073] (4) The axial installation deviation of the thrust bearing on the stern pontoon is z7, and the offset of the ship valve caused by the flexible deviation is z8=4800( ), the component ring ; 4800 is the length of the ship valve part.

[0074] (5) The axial manufacturing deviation of the thrust bearing is z9, and the offset of the thrust bearing end caused by the flexible deviation is z10=530( ), the component ring Z5=z9+z10; 530 is the length of the thrust bearing.

[0075] (6) The intermediate shaft manufacturing deviation offset is z11, and the offset of the clutch end of the reduction box module caused by the flexible deviation is z12=950( ), the component ring Z6=z11+z12; 950 is the length of the clutch of the reduction box module.

[0076] Since the direction of the offset is unknown, the above component rings can be considered as an increase ring, and therefore, the closed loop Z deviation size chain formula is: .

[0077] In each Monte Carlo iteration, the flexible deformation of the part is superimposed on the predicted deviation of the rigid deviation prediction model, and the statistical distribution of each measurement item is finally obtained by the Monte Carlo analysis formula.

[0078] The above steps are repeated ( more than 10000) times using the Monte Carlo method, and the mean deviation of the part feature point deviation is:

[0079] The standard deviation is:

[0080] Process capability index is:

[0081] wherein, is the mean deviation of all part feature point deviations, M is the total number of Monte Carlo simulations, is the deviation result calculated by the i-th simulation, is the standard deviation of all part feature point deviations, is the process capability index, which measures the index of whether the deviation distribution meets the design index, is the upper cut-off of the size deviation, is the lower cut-off of the size deviation.

[0082] The final rigid-flexible coupling deviation prediction model considers the relative model main shaft line deviation analysis results of the shafting stern end face free end under actual working conditions, as shown in Table 3, Table 3 is a rigid-flexible coupling deviation prediction model deviation analysis result table of the stern shaft end face, which includes deviation name and corresponding rigid-flexible coupling simulation results, for example, the rigid-flexible coupling simulation result of the stern shaft stern end face shaft line radial offset amount is: the upper cut-off is +3mm, the lower cut-off is -3mm, the out-of-tolerance rate is 74.09%, 6 4.64mm; the rigid-flexible coupling simulation result of the stern shaft stern end face shaft line axial offset amount is: the upper cut-off is +2mm, the lower cut-off is -2mm, the out-of-tolerance rate is 74.70%, 6 4.58mm; the rigid-flexible coupling simulation result of the stern shaft bearing stern end face and the propeller sealing device axial gap is: the upper cut-off is +2mm, the lower cut-off is -2mm, the out-of-tolerance rate is 74.34%, 6 4.56mm.

[0083] Table 3

[0084] ​The embodiment provides an assembly deviation prediction method based on a ship propulsion system, obtains manufacturing data of parts of a ship propeller, actual working conditions and load distribution information; constructs an assembly deviation transmission model based on the manufacturing data of the parts; simulates through a Monte Carlo method based on the deviation transmission model, constructs a rigid deviation prediction model, and the rigid deviation prediction model is used for predicting accumulated deviation of the propeller composed of multiple rigid parts after assembly is completed; performs flexible assembly deviation analysis on the rigid deviation prediction model based on a finite element method to obtain flexible deviation data; constructs a rigid-flexible coupling deviation prediction model based on the flexible deviation data and the rigid deviation prediction model; and predicts through the rigid-flexible coupling deviation prediction model according to the actual working conditions and the load distribution information to obtain overall assembly deviation of the ship propeller. The rigid-flexible coupling deviation prediction model coupling rigid body tolerance analysis and flexible deformation deviation is introduced, accurate prediction of the assembly deviation is realized, and then the assembly precision is effectively improved.

[0085] Based on the first embodiment of the application, in the second embodiment of the application, the same or similar contents as the above embodiment one can refer to the above introduction, and the subsequent will not be described in detail. On this basis, please refer to Figure 7 , step S30 further includes steps S301-S306: Step S301: setting the simulation times and parameter range, generating the manufacturing deviation and installation deviation of each part randomly in each simulation based on the deviation transmission model.

[0086] It should be noted that the simulation times refer to the total number of Monte Carlo simulations, and the parameter range refers to the value range of the manufacturing deviation and the installation deviation of each part. By setting the simulation times and the parameter range, the comprehensiveness and accuracy of the Monte Carlo simulation can be ensured. In each simulation, the manufacturing deviation and the installation deviation of each part are randomly generated according to the deviation transmission model to simulate the uncertainty in the actual assembly process.

[0087] It can be understood that in the process of establishing the propeller-shafting-module assembly rigidity deviation prediction model by using the Monte Carlo method, first, a ship modular assembly geometric model is established, including manufacturing deviations of various parts and installation deviations of the parts. The part assembly sequence and positioning reference are set, and the transmission chain of the cumulative manufacturing deviation and the positioning installation deviation is determined as from the stern tube-thrust bearing-intermediate shaft-stern shaft-propeller. The part manufacturing deviation and the cumulative installation deviation are transmitted to the propeller. The relative positions of the stern bearing, the shafting compensation device, the stern shaft sealing device, the emergency sealing device, and the shafting compensation device and the stern shaft are determined through the hole shaft cooperation relationship. The radial offset deviation ring of the stern end surface of the stern shaft is composed of the installation deviation of the centerline of the hull, the deviation of the base point mark of the tank raft, the offset of the thrust bearing and the tank raft, the tilt of the thrust bearing and the tank raft, the offset of the intermediate shaft and the thrust bearing, the tilt of the intermediate shaft and the thrust bearing, the offset of the tank raft reference and the installation reference of the tank, the tilt of the tank raft reference and the hull module installation reference, the offset of the stern shaft and the intermediate shaft, and the tilt of the stern shaft and the intermediate shaft. The axial offset deviation ring of the stern end surface of the stern shaft is composed of the axial machining deviation of the structural installation surface, the axial length size manufacturing deviation, the base point mark deviation of the tank raft, the axial installation deviation of the thrust bearing on the stern tank raft, the axial manufacturing deviation of the thrust bearing, the axial manufacturing deviation of the intermediate shaft, the axial deviation of the tank raft reference and the hull reference, and the axial length size manufacturing deviation of the stern shaft. The axial gap between the stern end surface of the stern bearing and the sealing device of the propeller is composed of the base point mark deviation of the tank raft, the axial installation deviation of the thrust bearing and the tank raft, the manufacturing deviation of the thrust bearing and the tank raft, the manufacturing deviation of the intermediate shaft, the axial installation deviation of the intermediate shaft and the thrust bearing, the angle offset of the tank raft reference and the shafting centerline, the angle tilt of the tank raft reference and the shafting centerline, the axial installation deviation of the stern end and the intermediate shaft, and the installation deviation of the stern end of the stern bearing and the intermediate shaft.

[0088] Step S302: According to the manufacturing deviation and the installation deviation, the cumulative deviation of the propeller in each simulation is calculated by simulating the assembly process by the Monte Carlo method.

[0089] It should be noted that in the Monte Carlo simulation assembly process, each simulation represents a possible assembly situation. Through a large number of simulations, the distribution of the cumulative deviation of the propeller can be counted, and the stability and reliability of the assembly quality can be analyzed. Specifically, in each simulation, according to the randomly generated manufacturing deviation and installation deviation, the assembly process of each part is simulated step by step, and the cumulative deviation after each assembly is calculated. In this way, at the end of each simulation, a cumulative deviation value of the propeller after assembly can be obtained. Through statistical analysis of a large number of simulation results, the distribution characteristics of the cumulative deviation, such as the mean, the standard deviation, and the like, and key quality indicators such as the out-of-tolerance rate can be obtained.

[0090] In an implementable embodiment, step S302 can comprise: calculating displacement wrenches of the deviation sources in the assembly process according to the manufacturing deviations and the installation deviations; constructing a sensitivity matrix for characterizing the influence degree / contribution coefficient of each deviation source on the cumulative deviation of the propeller; determining the cumulative deviation of each part or feature in the propeller according to the displacement wrenches and the sensitivity matrix; and calculating the cumulative deviation of the propeller in each simulation according to the cumulative deviation of each part or feature in the propeller.

[0091] It should be noted that the deviation sources refer to features of zero points, which will generate manufacturing deviations and installation deviations in the assembly process, and further affect the assembly accuracy of the entire propeller, such as positioning features, e.g., positioning holes, positioning surfaces, etc. By calculating the displacement wrenches of these deviation sources in the assembly process, the contribution of the deviation sources to the cumulative deviation of the propeller can be quantified. The construction of the sensitivity matrix is based on finite element analysis or theoretical derivation, and is used to reflect the response degree of the cumulative deviation of the propeller when each deviation source changes. In determining the cumulative deviation, the displacement wrenches and the sensitivity matrix are comprehensively considered.

[0092] It can be understood that when the rigid deviation prediction model of the propeller-shafting-module assembly is established using the Monte Carlo method, the deviation ranges of the geometric features of the parts in the assembly module composed of, for example, the power module-intermediate shaft-stern shaft-propeller and pressure hull are expressed in the deviation modeling process. According to the structural features of the parts and the assembly process, the manufacturing and assembly deviations of the ship module are imported, and the rigid deviation prediction model of the propeller-shafting-module assembly containing the manufacturing deviations and the assembly deviations of the parts is constructed to predict the cumulative deviation of the assembly body composed of multiple rigid parts after the final assembly is completed. The calculation formula of the cumulative deviation is:

[0093] wherein, is the vector of the final assembly deviation, which is the deviation of one or more key dimensions, e.g., the variation of a certain gap, is the total number of parts or features participating in the accumulation of the assembly deviation, is the displacement wrench of the i-th deviation source (e.g., the positioning feature of the part , and is the sensitivity matrix, which refers to the influence degree or contribution coefficient of the i-th deviation source on the final assembly deviation .

[0094] Step S303: statistically analyzing the cumulative deviation of the propeller in each simulation to obtain the rigid deviation distribution of the propeller under different combinations of manufacturing deviations and installation deviations.

[0095] ​​It should be noted that the Monte Carlo method is used to establish the propeller-shaft-module assembly rigidity deviation prediction model, and the mean value and standard deviation characteristics of the assembly deviation of the key measurement points are calculated to realize the assembly deviation analysis and obtain the rigidity deviation distribution. The rigidity deviation distribution parameters are shown in Table 4, which is a rigidity deviation distribution parameter table. The table includes the deviation source and the corresponding distribution characteristics. For example, the deviation source The corresponding distribution characteristics are , wherein represents a deviation source of a certain manufacturing deviation, such as the length manufacturing deviation of a certain part, , which is subject to a normal distribution with a mean value of 0 and a standard deviation of 0.25. The deviation source also includes , The statistical prediction characteristics of , , ,

[0096] Table 4

[0097] Step S304: Based on the rigidity deviation distribution, a random number generator is used to randomly sample the deviation sources and perform deviation analysis to obtain assembly deviation samples.

[0098] It should be noted that based on the rigidity deviation distribution, a random number generator is used to randomly sample each deviation source to simulate various deviation combinations that may occur during actual assembly. By analyzing these sampling data, a series of assembly deviation samples can be obtained, which reflect the assembly quality of the propeller under different combinations of manufacturing deviations and installation deviations. Through statistical analysis of these samples, the distribution law of the assembly deviation can be further understood.

[0099] In a specific implementation, a random number generator is used to randomly sample the deviation sources according to the rigidity deviation distribution parameters, and a deviation analysis is performed once for each sampling to obtain assembly deviation samples.

[0100] Step S305: Calculate the assembly deviation evaluation index based on the assembly deviation samples, and the assembly deviation evaluation index is determined according to the statistical characteristics of the assembly deviation.

[0101] It should be noted that the Monte Carlo method is used to establish the propeller-shaft-module assembly rigidity deviation prediction model, and the mean value and standard deviation characteristics of the assembly deviation of the key measurement points are calculated to realize the assembly deviation analysis and obtain the rigidity deviation distribution. The rigidity deviation distribution parameters are shown in Table 4, which is a rigidity deviation distribution parameter table. The table includes the deviation source and the corresponding distribution characteristics. For example, the deviation source ​

[0102] The standard deviation is:

[0103] The process capability index is:

[0104] in, is the mean of the deviation of the feature points of the part, that is, the arithmetic mean of all simulation results, is the standard deviation of the part feature point deviation, that is, the standard deviation of all simulation results, is the process capability index, is the total number of Monte Carlo simulations, For the The final deviation result calculated by the simulation is is the upper cutoff of size deviation, is the lower cutoff of size deviation.

[0105] Step S306: defining a deviation transmission chain, and constructing a rigid deviation prediction model based on the deviation transmission chain, the rigid deviation distribution, and the assembly deviation evaluation index.

[0106] It should be noted that under the modular assembly process of ships, the deviation transmission chain of the ship propeller through the shafting to the power system module and the final assembly is defined, and a rigid analysis assembly deviation model for the deviation transmission and accumulation between the ship propeller, shafting and module in the assembly process is established.

[0107] It can be understood that the deviation transmission chain refers to the deviation path that starts from the initial deviation source, passes through a series of assembly relationships and interactions between parts, and is finally transmitted to the target part or feature. In the assembly process of the ship propeller, the deviation transmission chain describes the process of how the manufacturing deviation and installation deviation of each component gradually accumulate through the assembly sequence and positioning reference and ultimately affect the overall assembly accuracy of the propeller. By clearly defining the deviation transmission chain, we can more clearly understand the transmission and accumulation mechanism of deviations in the assembly process, thereby providing a basis for constructing a rigid deviation prediction model. When constructing a rigid deviation prediction model, the deviation transmission chain, rigid deviation distribution, and assembly deviation evaluation indicators are comprehensively considered to achieve accurate prediction of propeller assembly deviations.

[0108] It is worth mentioning that the ship modular assembly power shafting rear shaft end face deviation analysis results in the rigid deviation prediction model are shown in Table 5, Table 5 is a rigid deviation model deviation analysis result table, which includes deviation name and corresponding rigid simulation results, for example, the rigid simulation result of the stern shaft stern end face axis radial offset is that the upper cut-off is +2mm, the lower cut-off is -2mm, and the out-of-tolerance rate is 5.30%, 6 6.18mm; the rigid simulation result of the stern shaft stern end face axis axial offset is that the upper cut-off is +2mm, the lower cut-off is -2mm, and the out-of-tolerance rate is 5.00%, 6 6.13mm; the rigid simulation result of the stern bearing stern end face and the propeller sealing device axial gap is that the upper cut-off is +2mm, the lower cut-off is -2mm, and the out-of-tolerance rate is 5.12%, 6 6.15mm.

[0109] Table 5

[0110] In this embodiment, the simulation times and parameter ranges are set, the manufacturing deviation and the installation deviation of each part are randomly generated in each simulation based on the deviation transmission model, the assembly process is simulated by the Monte Carlo method according to the manufacturing deviation and the installation deviation, the cumulative deviation of the propeller in each simulation is calculated, the cumulative deviation of the propeller in each simulation is statistically analyzed to obtain the rigid deviation distribution of the propeller under different combinations of manufacturing deviation and installation deviation, the deviation source is randomly sampled based on the rigid deviation distribution using a random number generator, and the deviation analysis is performed to obtain the assembly deviation sample, the assembly deviation evaluation index is calculated based on the assembly deviation sample, the assembly deviation evaluation index is determined according to the statistical characteristics of the assembly deviation, and the rigid deviation prediction model is constructed based on the deviation transmission chain, the rigid deviation distribution and the assembly deviation evaluation index. The simulation and analysis of the assembly deviation are introduced by the Monte Carlo method, the manufacturing deviation and the installation deviation of each part and their interaction in the assembly process are fully considered in the simulation process, the actual assembly situation can be more truly reflected, and the rigid deviation prediction model can be accurately constructed. Further, the prediction ability of the ship propeller assembly precision is effectively improved.

[0111] Based on the first embodiment of the present application, in the third embodiment of the present application, the same or similar contents as the above embodiment one can refer to the above introduction, and the subsequent will not be described in detail. On this basis, please refer to Figure 8 , step S40 further includes steps S401-S404: Step S401: Finite element simulation is performed on the rigidity deviation prediction model, and flexible deformation and stress distribution of the propeller in a working state are simulated by applying part self-weight and external load to obtain a finite element simulation result.

[0112] It should be noted that the flexible deformation deviation in the finite element method (FEA) includes the unbalanced mass distribution of rotating parts such as the propeller, shafting and the like due to manufacturing or wear, and uneven loads such as assembly loads and constraints, including the self-weight of the bearing part, the clamping force applied by the jig as a concentrated force or distributed force during the assembly process, the pre-tightening force of the bolt connection, and the connection force during module docking, etc. The flexible key node deformation deviation of the part key points under the action of the clamping force, the connection force and the self-weight during the assembly process is quantified and parameterized, and is integrated into the rigidity deviation prediction model obtained by preliminary analysis.

[0113] In a specific implementation, the model is subjected to finite element simulation in a finite element software, and the self-weight and external load of the part are applied to simulate the flexible deformation and stress distribution of the propeller, shafting and installation module in a working state. For example, the material can be set as AH32 steel, the elastic modulus is about 210 GPa, the Poisson's ratio is 0.3, the boundary conditions are set as that the propeller shaft end is fixedly supported through the ship body module, and the bearing is rotationally constrained, and the load conditions include the self-weight 2.5 kN·m of the shafting and the module and the engineering load simulation propelling force 500 kN acting in the axial direction, and the transverse load 200 kN acting on the propeller blade, and the present embodiment is not specifically limited thereto.

[0114] Step S402: Determine the measurement key point deformation data based on the finite element simulation result.

[0115] It should be noted that the measurement key point deformation data is obtained by using the finite element technology to correct the rigidity deviation prediction model, and extracting the deformation field and node displacement on the assembled part after the finite element analysis.

[0116] In a specific implementation, if the maximum deflection displacement of the free end of the shafting stern end surface relative to the model centerline in the simulation result is about 3.52 mm, and the torsion angle is about 0.12°, the measurement key point deformation data is obtained at the node.

[0117] It is worth mentioning that the finite element method is used to identify, quantify and characterize the factors affecting the prediction of flexible deviation, so as to modify the rigid deviation prediction model, use the screw model to characterize the influencing factors, and use the finite element key node analysis to quantify them. The implementation steps of the finite element key node method are as follows: The basic theory of rigid-flexible coupling is that there is elastic deformation deviation under the action of deadweight and external load. The relative displacement and rotation between key nodes are used as node coordinates to describe the deformation of the structure. The finite element analysis deformation is integrated into the assembly deviation, and the discrete node displacement of the key mating surface of each component is determined. Based on the characterization requirements and sampling frequency, the two mating planes of the contact surface need to be discretized as a mesh. The deformation of the nodes in the mesh can be obtained from the finite element analysis results, where the sampling point refers to the center point and the point where the deviation surface is defined in the finite element analysis flexible model. The finite element analysis result matrix is ​​expressed as follows:

[0118] in, is the number of mating surfaces ( ), The number of sample points on the surface for each defined flexibility deviation, For the The matrix of flexible deformations of the surfaces, and Respectively On the surface The X, Y, and Z coordinate values ​​of each sampling point.

[0119] Integrate the key point flexibility deviation into the rigid model and establish a rigid-flexible coupling system deviation prediction model. The establishment of the rigid-flexible coupling deviation prediction model is to build a rigid-flexible coupling assembly deviation transmission and deviation accumulation model taking into account the manufacturing deviation and assembly deformation factors. In the propeller-shaft-module assembly process, using multi-body system dynamics and finite element methods, the motion of the flexible body is decomposed into the motion of the reference coordinate system that describes the motion of the rigid body and the displacement of the node relative to the reference coordinate system that describes the elastic deformation. The entire propeller-shaft-module system is described as a unified system composed of a rigid body and a reduced-order flexible body connected by various kinematic pairs and force elements. Then, the key node coordinate method is used to describe the large-scale rigid motion and small elastic deformation of the flexible body when load and self-weight are applied. According to the displacement of each node on the simplified model and corners , the motion equation of the rigid body system and the modal dynamics equation of the elastic deformation of the flexible body are established, that is, the algebraic equation of the displacement relationship between components is described by using the relative radial deviation and the relative rotation angle deviation, the deviation value of the prediction model is converted into the following differential algebraic equation set, the deviation prediction model of the rigid-flexible coupling system is constructed, for example, the center of the joint surface at the shaft end A and the shaft end B is connected at the coupling, and the rotation angle parameter is used to represent The plane deviation is:

[0120] wherein, represents a 6x1-dimensional column vector of the deviation, that is, the displacement rotation, respectively represent the small translation amounts of the rigid body around the reference coordinate system X, Y, and Z axes, respectively represent the small rotation amounts (in radians) of the rigid body around the reference coordinate system X, Y, and Z axes.

[0121] wherein the relative radial deviation of the AB point is:

[0122] wherein, is the relative radial deviation of A and B, is the Y and Z direction displacement of the A point, is the Y and Z direction displacement of the B point.

[0123] The deflection angle (small angle approximation relative node angle) of the two component axes in the Y-Z plane is represented by using the finite element key unit, and the deviation is:

[0124]

[0125] wherein, , is the rotation angle deviation of the point and around the X axis, is the rotation angle component of the node.

[0126] Step S403: calculating the part stiffness matrix based on the measured key point deformation data.

[0127] It should be noted that the part stiffness matrix is a matrix used to describe the ability of the part to resist deformation under the action of external force. In finite element analysis, the deformation of the part under a certain load can be calculated to deduce the stiffness matrix of the part. The matrix reflects the relative rigidity and deformation coordination between parts, and is one of the important indicators for evaluating the structural performance of the part.

[0128] ​In a specific implementation, based on the measured key point deformation data, combined with the mechanical principle in finite element analysis, a stiffness equation of the part can be constructed. By solving the equation, the stiffness matrix of the part can be obtained. The elements in the matrix represent the deformation of each part under unit load, so that the rigidity and deformation characteristics of the part can be comprehensively evaluated.

[0129] In a feasible implementation, step S403 can include: determining key feature points based on the measured key point deformation data, wherein the key feature points are where the deviation sources affecting the assembly quality exist; applying a unit force opposite to the deviation direction on the finite element nodes corresponding to the key feature points to obtain displacement responses; constructing a displacement response vector of each key feature point according to the displacement responses and the unit force; generating a displacement response matrix based on the displacement response vectors of the key feature points; determining a compliance matrix of the part based on the displacement response matrix; and determining a stiffness matrix of the part based on the compliance matrix of the part.

[0130] It should be noted that there are deviation sources affecting the assembly quality at each key feature point. If needed key feature points exist deviation sources, a unit force method is used to apply a unit force opposite to the deviation direction on the finite element nodes of the key feature points in the finite element model, and the displacement responses of the key feature points are calculated and expressed in vector form as:

[0131] When a force is applied to the key feature point, the displacement response vector of the key feature point is:

[0132] By applying forces to each key feature point respectively, the matrix composed of the displacement response vectors of the key feature points is:

[0133] wherein represents the compliance matrix of the part, and the relationship between the stiffness matrix of the part and the compliance matrix is:

[0134] Step S404: determining deviations of each part under flexible deformation based on the stiffness matrix of the part and the finite element simulation result, to obtain flexible deviation data.

[0135] It should be noted that in the 3DCS model, the flexible deviation is applied to the corresponding nodes or feature points, and the rigid deviation is compensated with the deformation value of the measured point to obtain the coordinate displacement of the relevant points after deformation, and the stiffness matrix The flexibility deviation generated by the force applied to each key feature point when each column of corresponding points produces a unit displacement is characterized, and these deviations are combined with the original geometric tolerance in the assembly process.

[0136] In the specific implementation, the deviation transfer process in the assembly process is modeled as a whole, and the rigid-flexible coupling deviation integration formula in ship modular assembly is:

[0137] in, For measuring points The total deviation displacement matrix, Assembly step The cumulative displacement of Assembly step Assembly displacement caused by positioning coordination deviation, Positioning displacement for the part itself, is the assembly deviation displacement, The flexible deviation displacement caused by gravity and load factors is obtained through finite element calculation.

[0138] like Figure 9 As shown, Figure 9 The overall flow chart for constructing a rigid-flexible coupling deviation prediction model includes: constructing a ship propeller-shafting-modular assembly deviation transfer model; using the Monte Carlo method to predict the rigid assembly model deviation of the submarine propeller-shafting-modular assembly; performing flexible assembly deviation impact analysis and calculation based on the finite element method (FEA); and establishing a rigid-flexible coupling deviation prediction model for ship propeller-shafting-modular assembly.

[0139] In this embodiment, finite element simulation is performed on the rigidity deviation prediction model. By applying the self-weight of the part and external loads, the flexible deformation and stress distribution generated by the propeller in the working state are simulated to obtain finite element simulation results; based on the finite element simulation results, the deformation data of the key measurement points are determined; based on the deformation data of the key measurement points, the part stiffness matrix is ​​calculated; based on the part stiffness matrix and the finite element simulation results, the deviation of each part under flexible deformation is determined to obtain flexible deviation data. This application achieves accurate prediction of the flexible deformation deviation during the assembly process of the ship propeller through finite element simulation analysis combined with the rigidity deviation prediction model. It not only takes into account manufacturing deviations, but also incorporates deformation factors during the assembly process, thereby improving the accuracy of the prediction of assembly precision.

[0140] Exemplarily, in order to facilitate understanding of the implementation process of the ship propulsion system assembly deviation prediction method obtained after the above-mentioned embodiment one, please refer to Figure 10 , Figure 10 A detailed flowchart of assembly deviation prediction of the ship propulsion system assembly deviation prediction method is provided, specifically: feature decomposition is performed on part manufacturing data, a non-ideal surface is constructed, and a part real geometry model is generated by combining the non-ideal surface with a part ideal geometry model; a displacement rotation model is constructed according to the part real geometry model; a non-ideal surface deviation is obtained based on the displacement rotation model, and an assembly deviation is obtained based on the displacement rotation model combined with modular assembly constraint information; a deviation transmission model is constructed according to the non-ideal surface deviation and the assembly deviation; a rigid deviation prediction model is established by simulating the deviation transmission model by the Monte Carlo method; a rigid-flexible coupling deviation model is corrected based on the rigid deviation prediction model and rigid-flexible material parameter information, and then model optimization is performed to obtain a rigid-flexible coupling deviation prediction model; and the finite element method is used to perform deviation prediction according to the assembled product, the assembly process, and the assembly environment by the rigid-flexible coupling deviation prediction model.

[0141] It should be noted that the above examples are only used for understanding the present application and do not constitute a limitation on the ship propulsion system assembly deviation prediction method of the present application. More forms of simple transformation based on this technical concept are within the protection scope of the present application.

[0142] The present application also provides a ship propulsion system assembly deviation prediction device, which comprises: An acquisition module is configured to acquire part manufacturing data, actual working conditions, and load distribution information of a ship propeller.

[0143] A construction module is configured to construct an assembly deviation transmission model based on the part manufacturing data.

[0144] A simulation module is configured to simulate based on the deviation transmission model by the Monte Carlo method, construct a rigid deviation prediction model, and use the rigid deviation prediction model to predict the cumulative deviation of a propeller composed of multiple rigid parts after assembly is completed.

[0145] An analysis module is configured to perform flexible assembly deviation analysis on the rigid deviation prediction model based on the finite element method, and obtain flexible deviation data.

[0146] The construction module is further configured to construct a rigid-flexible coupling deviation prediction model based on the flexible deviation data and the rigid deviation prediction model.

[0147] A prediction module is configured to perform prediction according to the actual working conditions and the load distribution information by the rigid-flexible coupling deviation prediction model, and obtain the overall assembly deviation of the ship propeller.

[0148] The ship propulsion system assembly deviation prediction device provided by the present application adopts the ship propulsion system assembly deviation prediction method in the above embodiment, and can solve the technical problem of low assembly deviation prediction accuracy of the prior art. Compared with the prior art, the ship propulsion system assembly deviation prediction device provided by the present application has the same beneficial effects as the ship propulsion system assembly deviation prediction method provided by the above embodiment, and other technical features of the ship propulsion system assembly deviation prediction device are the same as the features disclosed in the above embodiment method, which will not be repeated here.

[0149] The present application provides a ship propeller, which is applied to the ship propulsion system assembly deviation prediction method as described above.

[0150] The present application provides a computer-readable storage medium having computer-readable program instructions (i.e., computer programs) stored thereon, which are used to execute the ship propulsion system assembly deviation prediction method in the above embodiment.

[0151] The present application also provides a computer program product comprising a computer program, which, when executed by a processor, implements the steps of the ship propulsion system assembly deviation prediction method as described above.

[0152] The computer program product provided by the present application can solve the technical problem of low assembly deviation prediction accuracy of the prior art. Compared with the prior art, the computer program product provided by the present application has the same beneficial effects as the ship propulsion system assembly deviation prediction method provided by the above embodiment, which will not be repeated here.

[0153] The above only describes some embodiments of the present application, and does not limit the patent scope of the present application. Any equivalent structural transformation made by using 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 method for predicting assembly deviation based on a ship propulsion system, characterized in that: The method comprises: Obtaining manufacturing data, actual operating conditions, and load distribution information for ship propulsion components; Building an assembly deviation transfer model based on the component manufacturing data; Based on the deviation transfer model, a Monte Carlo simulation is performed to construct a rigidity deviation prediction model, wherein the rigidity deviation prediction model is used to predict the cumulative deviation of a propeller composed of multiple rigid parts after assembly; Performing flexible assembly deviation analysis on the rigid deviation prediction model based on the finite element method to obtain flexible deviation data; Constructing a rigid-flexible coupling deviation prediction model based on the flexible deviation data and the rigid deviation prediction model; The rigid-flexible coupling deviation prediction model is used to perform prediction based on the actual working conditions and load distribution information to obtain the overall assembly deviation of the ship propulsion system.

2. The method according to claim 1, wherein The step of constructing an assembly deviation transfer model based on the component manufacturing data includes: Performing feature decomposition based on the component manufacturing data to obtain feature vectors of multiple parts; constructing a non-ideal surface based on the feature vectors of each of the parts, wherein the non-ideal surface is used to simulate actual surface deviations of the parts produced during the manufacturing process; Constructing a real geometric model of the part based on the non-ideal surface and the ideal geometric model of the part; Obtaining a parts assembly sequence and a positioning reference, and determining a manufacturing deviation and an installation deviation based on the parts' true geometric model, the parts assembly sequence, and the positioning reference; determining a deviation transfer relationship based on the manufacturing deviation and the installation deviation; An assembly deviation transfer model is constructed based on the deviation transfer relationship, and the assembly deviation transfer model is used to simulate the transfer and accumulation of deviations of various parts during the assembly process.

3. The method according to claim 1, wherein The method of performing simulation based on the deviation transfer model by the Monte Carlo method to construct a rigid deviation prediction model includes: Setting the number of simulations and parameter ranges, and randomly generating manufacturing deviations and installation deviations of each part in each simulation based on the deviation transfer model; Simulating the assembly process using the Monte Carlo method based on the manufacturing deviation and the installation deviation, and calculating the cumulative deviation of the thruster in each simulation; Performing statistical analysis on the cumulative deviation of the propeller in each simulation to obtain the rigidity deviation distribution of the propeller under different combinations of manufacturing deviation and installation deviation; Based on the rigid deviation distribution, a random number generator is used to randomly sample the deviation source and perform deviation analysis to obtain the assembly deviation sample; Calculating an assembly deviation evaluation index based on the assembly deviation sample, wherein the assembly deviation evaluation index is determined according to statistical characteristics of the assembly deviation; A deviation transmission chain is defined, and a rigidity deviation prediction model is constructed based on the deviation transmission chain, the rigidity deviation distribution, and the assembly deviation evaluation index.

4. The method according to claim 3, wherein The method of simulating the assembly process by using the Monte Carlo method according to the manufacturing deviation and the installation deviation, and calculating the cumulative deviation of the propeller in each simulation, comprises: Calculating the displacement torque of the deviation source during the assembly process based on the manufacturing deviation and the installation deviation; Constructing a sensitivity matrix, wherein the sensitivity matrix is ​​used to characterize the influence degree / contribution coefficient of each deviation source on the cumulative deviation of the thruster; determining cumulative deviations of various parts or features in the thruster based on the displacement spin and the sensitivity matrix; The cumulative deviation of the propeller in each simulation is calculated based on the cumulative deviation of each part or feature in the propeller.

5. The method according to claim 1, wherein The flexible assembly deviation analysis is performed on the rigid deviation prediction model based on the finite element method to obtain flexible deviation data, including: Performing finite element simulation on the rigidity deviation prediction model, simulating the flexible deformation and stress distribution of the propeller in a working state by applying the deadweight of the part and external loads, and obtaining finite element simulation results; Determining deformation data of key measurement points based on the finite element simulation results; Calculating a part stiffness matrix based on the deformation data of the measured key points; Based on the part stiffness matrix and finite element simulation results, the deviation of each part under flexible deformation is determined to obtain flexible deviation data.

6. The method according to claim 5, wherein The calculating of the part stiffness matrix based on the measured key point deformation data includes: Determining key feature points based on the measured deformation data of the key points, wherein a deviation source that affects assembly quality exists at the key feature points; Applying a unit force opposite to the deviation direction to the finite element node corresponding to the key feature point to obtain a displacement response; constructing a displacement response vector of each key feature point according to the displacement response and the unit force; generating a displacement response matrix based on the displacement response vectors of the key feature points; determining a compliance matrix of the part based on the displacement response matrix; A part stiffness matrix is ​​determined based on the flexibility matrix of the part.

7. The method according to claim 1, wherein The step of constructing a rigid-flexible coupling deviation prediction model based on the flexible deviation data and the rigid deviation prediction model includes: Converting the flexible deviation data into a displacement field form to obtain node displacement data; Performing deviation analysis based on the node displacement data and the rigid deviation prediction model to obtain a rigid-flexible coupling deviation distribution; Based on the rigid-flexible coupling deviation distribution, the influence of different loads on the deviation under actual working conditions is simulated to obtain the deviation mapping relationship in the rigid-flexible coupling deviation prediction model; A rigid-flexible coupling deviation prediction model is constructed based on the deviation mapping relationship.

8. An assembly deviation prediction device based on a ship propulsion system, characterized in that: The assembly deviation prediction device based on the ship propulsion system includes: An acquisition module is used to obtain the manufacturing data of ship propulsion components, actual working conditions and load distribution information; A construction module, configured to construct an assembly deviation transfer model based on the component manufacturing data; A simulation module, configured to perform simulation using a Monte Carlo method based on the deviation transfer model to construct a rigidity deviation prediction model, wherein the rigidity deviation prediction model is configured to predict the cumulative deviation of a propeller composed of a plurality of rigid parts after assembly; An analysis module, configured to perform flexible assembly deviation analysis on the rigid deviation prediction model based on a finite element method to obtain flexible deviation data; The construction module is further configured to construct a rigid-flexible coupling deviation prediction model based on the flexible deviation data and the rigid deviation prediction model; The prediction module is used to predict the overall assembly deviation of the ship propulsion system according to the actual working conditions and load distribution information through the rigid-flexible coupling deviation prediction model.

9. A ship propulsion device, characterized in that: The ship propulsion system is applied to the assembly deviation prediction method based on the ship propulsion system according to any one of claims 1 to 7.

10. A storage medium, characterized in that: The storage medium stores an assembly deviation prediction program based on a ship propulsion system, and when the assembly deviation prediction program based on a ship propulsion system is executed by a processor, the assembly deviation prediction method based on a ship propulsion system according to any one of claims 1 to 7 is implemented.

Images