Method and device for predicting assembly deviations based on a ship propulsion system

Abstract

The application discloses a kind of based on ship propulsion system's assembly deviation prediction method and device, comprising: obtaining the manufacturing data of ship propeller parts, actual working condition and load distribution information;Based on the manufacturing data of parts, construct assembly deviation transmission model;Based on deviation transmission model, simulation is carried out by Monte Carlo method, construct rigid deviation prediction model;Based on finite element method, flexible assembly deviation analysis is carried out to rigid deviation prediction model, and flexible deviation data is obtained;Based on flexible deviation data and rigid deviation prediction model, construct rigid-flexible coupling deviation prediction model;Through rigid-flexible coupling deviation prediction model, according to actual working condition and load distribution information, the overall assembly deviation of ship propeller is obtained, by introducing the rigid-flexible coupling deviation prediction model that rigid body tolerance analysis is coupled with flexible deformation deviation, accurate prediction of assembly deviation is realized, and then assembly precision is effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ship manufacturing, and particularly relates 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, and it is difficult to establish a reliable prediction model, which has become a major technical bottleneck restricting assembly quality optimization. The quality of the deviation transmission model construction directly affects the effectiveness of subsequent accuracy prediction and process optimization.

[0003] The assembly process deviation of the propeller-shaft system-module has a prominent effect on the final assembly accuracy of the ship. The ship propeller and shaft system can produce torsional and lateral 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, the operation deviates 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 sources and action mechanisms 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, aiming at solving the technical problem of low assembly deviation prediction accuracy 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:

[0007] Obtaining the part manufacturing data, actual working condition and load distribution information of the ship propeller;

[0008] Constructing an assembly deviation transmission model based on the part manufacturing data;

[0009] simulate based on the bias transmission model by a Monte Carlo method to construct a rigid bias prediction model, the rigid bias prediction model being used to predict the cumulative bias of the propeller composed of multiple rigid parts after assembly is completed;

[0010] perform flexible assembly bias analysis on the rigid bias prediction model based on a finite element method to obtain flexible bias data;

[0011] construct a rigid-flexible coupling bias prediction model based on the flexible bias data and the rigid bias prediction model;

[0012] obtain the overall assembly bias of the ship propeller by the rigid-flexible coupling bias prediction model according to the actual working condition and load distribution information.

[0013] In an embodiment, the constructing an assembly bias transmission model based on the part manufacturing data comprises:

[0014] perform feature decomposition based on the part manufacturing data to obtain feature vectors of multiple parts;

[0015] construct non-ideal surfaces based on the feature vectors of the parts, the non-ideal surfaces being used to simulate actual surface bias of the parts generated in the manufacturing process;

[0016] construct real geometry models of the parts based on the non-ideal surfaces and ideal geometry models of the parts;

[0017] obtain part assembly sequences and positioning references, determine manufacturing bias and installation bias based on the real geometry models of the parts, the part assembly sequences and the positioning references;

[0018] determine bias transmission relationships based on the manufacturing bias and the installation bias;

[0019] construct an assembly bias transmission model based on the bias transmission relationships, the assembly bias transmission model being used to simulate transmission and accumulation of bias of each part in the assembly process.

[0020] In an embodiment, the simulating based on the bias transmission model by a Monte Carlo method to construct a rigid bias prediction model comprises:

[0021] set simulation times and parameter ranges, randomly generate manufacturing bias and installation bias of each part in each simulation based on the bias transmission model;

[0022] simulate the assembly process by a Monte Carlo method according to the manufacturing bias and the installation bias to calculate the cumulative bias of the propeller in each simulation;

[0023] statistically analyzing the accumulated deviation of the thruster in each simulation to obtain a rigid deviation distribution of the thruster under different combinations of manufacturing deviation and installation deviation;

[0024] randomly sampling and analyzing the deviation sources based on the rigid deviation distribution to obtain an assembly deviation sample;

[0025] calculating an assembly deviation evaluation index based on the assembly deviation sample, the assembly deviation evaluation index being determined according to statistical characteristics of the assembly deviation;

[0026] 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.

[0027] In an embodiment, the rigid deviation distribution is obtained by simulating the assembly process according to the manufacturing deviation and the installation deviation through a Monte Carlo method, and calculating the accumulated deviation of the thruster in each simulation, including:

[0028] calculating a displacement rotation of the deviation sources in the assembly process according to the manufacturing deviation and the installation deviation;

[0029] constructing a sensitivity matrix, the sensitivity matrix being used to represent the influence degree / contribution coefficient of each deviation source on the accumulated deviation of the thruster;

[0030] determining the accumulated deviation of each part or feature in the thruster according to the displacement rotation and the sensitivity matrix;

[0031] calculating the accumulated deviation of the thruster in each simulation according to the accumulated deviation of each part or feature in the thruster.

[0032] In an embodiment, the flexible assembly deviation of the rigid deviation prediction model is analyzed based on a finite element method to obtain flexible deviation data, including:

[0033] performing finite element simulation on the rigid deviation prediction model, simulating the flexible deformation and stress distribution of the thruster in a working state by applying part self-weight and external load to obtain finite element simulation results;

[0034] determining measurement key point deformation data based on the finite element simulation results;

[0035] calculating a part stiffness matrix based on the measurement key point deformation data;

[0036] determining the deviation of each part under flexible deformation based on the part stiffness matrix and the finite element simulation results to obtain the flexible deviation data.

[0037] In an embodiment, the part stiffness matrix is calculated based on the measurement key point deformation data, including:

[0038] determining a key feature point based on the measured key point deformation data, wherein a deviation source affecting assembly quality exists at the key feature point;

[0039] applying a unit force in a direction opposite to the deviation direction on a finite element node corresponding to the key feature point to obtain a displacement response;

[0040] constructing a displacement response vector of each key feature point according to the displacement response and the unit force;

[0041] generating a displacement response matrix based on the displacement response vectors of the key feature points;

[0042] determining a flexibility matrix of the part based on the displacement response matrix;

[0043] determining a stiffness matrix of the part based on the flexibility matrix of the part.

[0044] In an embodiment, the constructing a rigid-flexible coupling deviation prediction model based on the flexible deviation data and the rigid deviation prediction model comprises:

[0045] converting the flexible deviation data into a displacement field form to obtain node displacement data;

[0046] performing deviation analysis according to the node displacement data and the rigid deviation prediction model to obtain a rigid-flexible coupling deviation distribution;

[0047] 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;

[0048] constructing a rigid-flexible coupling deviation prediction model based on the deviation mapping relationship.

[0049] In addition, to achieve the above object, the application further provides an assembly deviation prediction device based on a ship propulsion system, which comprises:

[0050] an acquisition module configured to acquire part manufacturing data, actual working conditions and load distribution information of a ship propeller;

[0051] a construction module configured to construct an assembly deviation transfer model based on the part manufacturing data;

[0052] a simulation module configured to simulate by a Monte Carlo method based on the deviation transfer model to construct a rigid deviation prediction model, wherein the rigid deviation prediction model is used to predict the cumulative deviation of the propeller composed of multiple rigid parts after assembly is completed;

[0053] 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;

[0054] 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.

[0055] a prediction module, configured to perform prediction according to the actual working condition and the load distribution information through the rigid-flexible coupling deviation prediction model to obtain the overall assembly deviation of the ship propeller.

[0056] In addition, to achieve the above object, the present application further provides a ship propeller, which is applied to the assembly deviation prediction method based on a ship propelling system as described above.

[0057] In addition, to achieve the above object, the present 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 assembly deviation prediction method based on a ship propelling system as described above.

[0058] In addition, to achieve the above object, the present 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 assembly deviation prediction method based on a ship propelling system as described above.

[0059] The one or more technical solutions provided by the present application obtain the part manufacturing data, the actual working condition and the load distribution information of the ship propeller; construct an assembly deviation transmission model based on the part manufacturing data; perform simulation through a Monte Carlo method based on the deviation transmission model to construct a rigid deviation prediction model, which is used to predict the cumulative deviation of the propeller composed of multiple rigid parts after assembly; perform flexible assembly deviation analysis on the rigid deviation prediction model based on a finite element method to obtain flexible deviation data; construct a rigid-flexible coupling deviation prediction model based on the flexible deviation data and the rigid deviation prediction model; and perform prediction according to the actual working condition and the load distribution information through the rigid-flexible coupling deviation prediction model to obtain the overall assembly deviation of the ship propeller. By introducing the rigid-flexible coupling deviation prediction model coupling rigid tolerance analysis and flexible deformation deviation, the present application realizes accurate prediction of assembly deviation, and effectively improves assembly precision. BRIEF DESCRIPTION OF DRAWINGS

[0060] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments consistent with the present application and serve to explain the principles of the present application together with the specification.

[0061] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, for those skilled in the art, other drawings can also be obtained based on these drawings without any creative effort.

[0062] Figure 1 A flowchart provided by the embodiment one of the method for predicting assembly deviation based on the ship propulsion system of the present application;

[0063] Figure 2 A schematic diagram of ship propeller-shafting-modular assembly provided by the embodiment one of the method for predicting assembly deviation based on the ship propulsion system of the present application;

[0064] Figure 3 A schematic diagram of the structure of each component in the ship propeller-shafting-modular assembly provided by the embodiment one of the method for predicting assembly deviation based on the ship propulsion system of the present application;

[0065] Figure 4 A schematic diagram of the flexible deformation deviation of the key points of the parts in the ship propeller-shafting-modular assembly under the action of clamping force, connecting force and self-gravity in the assembly process provided by the embodiment one of the method for predicting assembly deviation based on the ship propulsion system of the present application;

[0066] Figure 5 A diagram of the relationship between the axial displacement offset and the maximum stress provided by the embodiment one of the method for predicting assembly deviation based on the ship propulsion system of the present application;

[0067] Figure 6 A diagram of the relationship between the axial angle offset and the maximum stress provided by the embodiment one of the method for predicting assembly deviation based on the ship propulsion system of the present application;

[0068] Figure 7 A flowchart provided by the embodiment two of the method for predicting assembly deviation based on the ship propulsion system of the present application;

[0069] Figure 8 A flowchart provided by the embodiment three of the method for predicting assembly deviation based on the ship propulsion system of the present application;

[0070] Figure 9 A whole flowchart of the construction of the rigid-flexible coupling deviation prediction model provided by the embodiment one of the method for predicting assembly deviation based on the ship propulsion system of the present application;

[0071] Figure 10 A detailed flowchart of the assembly deviation prediction provided by the embodiment one of the method for predicting assembly deviation based on the ship propulsion system of the present application.

[0072] BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Propeller 1, shafting compensation device 2, stern shaft sealing device 3, thrust bearing 4, intermediate shaft 5 gear reduction box 6, hull module 7, power device 8, propeller sealing device 9, stern shaft 10 and hatch valve 11.

[0074] The object, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0075] It should be understood that the specific embodiments described herein are merely intended to explain the technical solutions of the present application, and are not intended to limit the present application.

[0076] In order to better understand the technical solutions of the present application, the specific embodiments will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0077] The main solution of the embodiment of the present 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 of the rigid deviation prediction model is carried out, 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; through the rigid-flexible coupling deviation prediction model, the actual working condition and load distribution information are predicted, and the overall assembly deviation of the ship propeller is obtained.

[0078] 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, the ship deviation prediction mainly adopts numerical analysis methods such as probability method and extreme value method to analyze the tolerance of the assembly dimension 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.

[0079] The present application provides a solution, which realizes accurate prediction of assembly deviation by introducing a rigid-flexible coupling deviation prediction model coupling rigid tolerance analysis and flexible deformation deviation, thereby effectively improving the assembly precision.

[0080] It should be noted that the execution subject of the 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, a ship propeller, etc. capable of realizing the above functions. The ship propeller is taken as an example to describe the embodiment and the following embodiments.

[0081] Based on this, the embodiment of the present application provides an assembly deviation prediction method based on a ship propulsion system, which is described with reference to Figure 1 , Figure 1 The flowchart of the first embodiment of the assembly deviation prediction method based on the ship propulsion system of the present application is shown in the figure.

[0082] In the embodiment, the assembly deviation prediction method based on the ship propulsion system comprises steps S10-S60:

[0083] Step S10: Obtain the part manufacturing data, actual working condition and load distribution information of the ship propeller.

[0084] 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 deviations and the flexible deformation caused by the self-weight of the parts, assembly stress and load, etc., and then carries out assembly prediction, which can effectively improve the actual precision of assembly deviation prediction.

[0085] 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 running 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.

[0086] Step S20: Construct an assembly deviation transfer model based on the part manufacturing data.

[0087] It should be noted that the assembly deviation transmission model is a mathematical model used to describe the deviation transmission law of ship propeller parts during assembly process. The model can consider the influence of factors such as geometric relationship between parts, material properties, assembly process, etc. on assembly deviation, so as to realize accurate prediction of assembly deviation. When constructing the assembly deviation transmission model, the manufacturing accuracy of parts, assembly sequence, assembly constraint conditions, etc. should be fully considered to ensure the accuracy and reliability of the model.

[0088] 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 during the manufacturing process; constructing a real geometry model of the parts based on the non-ideal surfaces and an 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; and 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 part deviations during the assembly process.

[0089] It should be noted that feature decomposition refers to decomposing the features such as geometry and size of parts in order to more accurately describe and analyze the deviation of parts during the manufacturing and assembly process. Through feature decomposition, feature vectors of parts can be obtained, which reflect the size and shape changes of parts in different directions.

[0090] It can be understood that based on the feature vectors of the parts, non-ideal surfaces can be constructed. Non-ideal surfaces refer to surfaces of parts that have certain deviations from ideal geometry due to various factors (such as machining errors, material deformation, etc.) during actual manufacturing process. By simulating these actual surface deviations, the actual situation of parts during the manufacturing process can be more realistically reflected.

[0091] Further, in combination with the ideal geometry model of the parts and the non-ideal surfaces, a real geometry model of the parts can be constructed. This real geometry model contains not only the ideal shape and size information of the parts, but also the actual shape and size change information due to manufacturing deviations.

[0092] After obtaining the real geometry 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] It should be noted that the finite element method is a numerical analysis method that discretizes complex physical problems into a series of simple unit problems for solution. In this embodiment, the finite element method is used to perform flexible assembly deviation analysis on the rigid deviation prediction model, which can simulate the flexible deformation of the thruster during assembly due to the weight of the parts, assembly stress and load, etc.

[0100] Specifically, the rigid deviation prediction model is introduced into the finite element analysis software, the corresponding boundary conditions and loads are set, and then simulation calculation is performed. Through simulation calculation, the simulation results such as stress distribution and deformation of the propeller in the assembly process can be obtained, and then the simulation results are analyzed and processed, and the flexible deviation data are extracted. The flexible deviation data reflect the flexible deformation of the propeller in the assembly process due to factors such as part weight, assembly stress and load, and are an important basis for subsequent construction of a rigid-flexible coupling deviation prediction model.

[0101] Step S50: constructing a rigid-flexible coupling deviation prediction model based on the flexible deviation data and the rigid deviation prediction model.

[0102] 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.

[0103] 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.

[0104] It is worth noting that by comprehensively and effectively representing and analyzing the rigid-flexible coupling influencing factors, introducing the flexible deformation deviation obtained by finite element simulation into the deviation analysis process, realizing the coupling of rigid body tolerance analysis and flexible deformation deviation, and obtaining the rigid-flexible coupling deviation prediction model, the actual deformation in the assembly process can be more comprehensively reflected, the ship propeller-shaft system-module assembly deviation predicted by the rigid-flexible coupling deviation prediction model is improved in prediction accuracy, and quantitative basis is provided for assembly scheme optimization.

[0105] In the specific implementation, the model deviation transmission relationship and typical rigid and flexible components are defined. The shafting, intermediate shaft, stern shaft, and hull module are the objects of flexible deviation analysis, and deviation distribution parameters are set. Then, finite element analysis software is used to perform flexible assembly deviation analysis on these flexible components. By simulating the deformation and displacement of these components during assembly, flexible deviation data is obtained. This data includes assembly deviations caused by component deformation, which is crucial for accurately predicting overall assembly accuracy. The flexible assembly deviation analysis pays special attention to the deformation of key components such as the shafting, intermediate shaft, and stern shaft. These components are subjected to various forces during assembly, such as gravity, preload, and assembly forces, making them prone to deformation and affecting assembly accuracy. Finite element analysis can calculate the deformation of these components under stress, thus obtaining flexible deviation data. Simultaneously, considering the complexity of large components such as the hull module, appropriate simplifications and assumptions are used to reduce the analysis difficulty. For example, the hull module can be simplified into shell elements or body elements with equivalent stiffness and mass, thereby improving computational efficiency while ensuring analytical accuracy. Based on the obtained flexible deviation data and rigid deviation prediction model, a rigid-flexible coupling deviation prediction model is further constructed. This model comprehensively considers the assembly deviations of rigid and flexible components, enabling more accurate prediction of the overall assembly accuracy of the ship's propeller. Through the rigid-flexible coupling deviation prediction model, predictions can be made based on actual operating conditions and load distribution information to obtain the overall assembly deviation value of the ship's propeller. These prediction results are of great significance for guiding the assembly process, optimizing assembly techniques, and improving assembly accuracy.

[0106] like Figure 2 As shown, Figure 2 This is a schematic diagram of a ship's propulsion system-shafting modular assembly. The propulsion system is assembled with other modules of the ship through the shafting system. The shafting system is a transmission shafting system. The modules include Module 1 and Module 2. Module 1 consists of a reduction gear, a power unit, and inlet / outlet piping systems connected to the integrated installation platform.

[0107] like Figure 3 As shown, Figure 3 This is a schematic diagram of the structure of each component in the ship propulsion-shafting-module assembly. The ship propulsion-shafting-module assembly includes the propulsion unit 1, shafting compensation device 2, stern shaft sealing device 3, thrust bearing 4, intermediate shaft 5, gear reducer 6, hull module 7, power unit 8, propulsion sealing device 9, stern shaft 10, and hatch valve 11.

[0108] like Figure 4 As shown, 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 .

[0109] 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.

[0110] 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 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.

[0111] 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.

[0112] It is worth mentioning that the analysis of the influence of the load on the deviation obtains the rigid-flexible coupling deviation distribution, the simulation of the influence of the different loads on the stern face under the actual working conditions obtains the mathematical relationship between the rigid-flexible coupling deviation prediction model and the deflection, the maximum stress on the shafting is taken as the main index, the relationship between the axial displacement deflection and the maximum stress and the relationship between the axial angle deflection and the maximum stress are obtained, and the deviation mapping relationship in the rigid-flexible coupling deviation prediction model can be obtained according to the relationship.

[0113] As shown in Table 1, Table 1 is an axial displacement deflection and maximum stress relationship table, which includes the deflection / mm and the corresponding maximum stress / MPa, for example, the deflection including 0, 3, 5, 7, 8, etc., and the corresponding maximum stress / MPa is 93.08, 94.19, 96.57, 103.9, 108.8, respectively.

[0114] Table 1

[0115]

[0116] As shown in Table 2, Table 2 is an axial angle deflection and maximum stress relationship table, which includes the deflection / ° and the corresponding maximum stress / MPa, for example, the deflection / ° includes 0, 0.5, 0.6, 0.8, etc., and the corresponding maximum stress / MPa is 93.08, 98.45, 98.88, 104.5, respectively.

[0117] Table 2

[0118]

[0119] As Figure 5 shown, Figure 5 is an axial displacement deflection and maximum stress relationship diagram, which includes the deflection / ° and the corresponding maximum stress / MPa, for example, the deflection / ° includes 0, 0.5, 0.6, 0.8, etc., and the corresponding maximum stress / MPa is 93.08, 98.45, 98.88, 104.5, etc., and there is a nearly linear relationship between the maximum stress growth and the shafting deflection.

[0120] As Figure 6 shown, Figure 6 is an axial angle deflection and maximum stress relationship diagram, which includes the deflection / ° and the corresponding maximum stress / MPa, for example, 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.

[0121] 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 face after assembly is obtained through joint analysis, and the calculation formula is:

[0122]

[0123] wherein, 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).

[0124] Step S60: predicting through 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.

[0125] 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.

[0126] 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 can analyze the working condition and load distribution as model input through the cooperative use of finite element simulation and Monte Carlo method, predict the assembly deviation through the rigid-flexible coupling deviation prediction model, thereby improve the assembly precision, effectively couple the geometric deviation and flexible deformation deviation of assembly, and realize the accurate prediction and optimization of the ship propeller-shaft system-module assembly deviation.

[0127] In a specific implementation, the deviation is calculated from the cabin valve-power device-intermediate shaft-stern shaft-propeller deviation transmission chain, and the stern shaft end surface axial deviation is taken as an example for illustration. The closed loop Z is formed by the axial deviation of the stern shaft end surface to the end of the power shaft. For the turning angle deviation, each component ring is:

[0128] (1) The axial machining deviation z1 of the stern shaft propeller mounting surface structure, and the deviation of the end of the stern shaft caused by the flexibility deviation is , and the component ring is formed; 3600 is the length of the stern shaft.

[0129] (2) The axial length dimension manufacturing deviation z3 of the stern shaft, and the deviation of the end of the intermediate shaft caused by the flexibility deviation is , and the component ring is formed; 1000 is the length of the intermediate shaft.

[0130] (3) The cabin raft base point identification deviation z5, and the deviation of the end of the power shaft of the gear reducer module caused by the flexibility deviation is , and the component ring is formed; 1000 is the length of the power shaft of the gear reducer module.

[0131] (4) The axial installation deviation z7 of the thrust bearing on the stern cabin raft, and the deviation z8=4800 caused by the flexibility of the ship valve is , and the component ring is formed; 4800 is the length of the ship valve part.

[0132] (5) The axial manufacturing deviation z9 of the thrust bearing, and the deviation z10=530 caused by the flexibility of the end of the thrust bearing is , and the component ring Z5=z9+z10 is formed; 530 is the length of the thrust bearing.

[0133] (6) The intermediate shaft axial manufacturing deviation z11, and the deviation z12=950 caused by the flexibility of the end of the clutch of the reduction box module is , and the component ring Z6=z11+z12 is formed; 950 is the length of the clutch of the reduction box module.

[0134] Since the direction of the deviation is unknown, the above component rings can be considered as augmented rings, and therefore, the closed loop Z deviation size chain formula is: .

[0135] In each Monte Carlo iteration, the flexibility 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 from the Monte Carlo analysis formula.

[0136] The above steps are repeated using the Monte Carlo method ( ​The mean deviation of the part feature point deviation is:

[0137]

[0138] The standard deviation is:

[0139]

[0140] The process capability index is:

[0141]

[0142] 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.

[0143] 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. The table includes deviation names 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 is: the upper cut-off is +3mm, the lower cut-off is -3mm, the out-of-tolerance rate is 74.09%, and the out-of-tolerance rate is 74.09%. The rigid-flexible coupling simulation result of the stern shaft stern end face shaft line axial offset is: the upper cut-off is +2mm, the lower cut-off is -2mm, the out-of-tolerance rate is 74.70%, and the out-of-tolerance rate is 74.70%. The rigid-flexible coupling simulation result of the stern 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%, and the out-of-tolerance rate is 74.34%. The rigid-flexible coupling simulation result of the stern 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%, and the out-of-tolerance rate is 74.34%.

[0144] Table 3

[0145]

[0146] ​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.

[0147] 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:

[0148] 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.

[0149] 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.

[0150] 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 installation reference of the hull, 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 ring 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.

[0151] 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.

[0152] 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 then 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.

[0153] 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.

[0154] 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.

[0155] It can be understood that when the Monte Carlo method is used to establish the rigid deviation prediction model of the propeller-shafting-module assembly, 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:

[0156]

[0157] wherein, is the vector of the final assembly deviation, which is the deviation of one or more key dimensions, e.g., the change amount 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 th deviation source (e.g., the positioning feature of the part , is the sensitivity matrix, which refers to the influence degree or contribution coefficient of the th deviation source on the final assembly deviation .

[0158] 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.

[0159] It should be noted that the Monte Carlo method is used to establish a propeller-shaft-module assembly rigidity deviation prediction model, and the mean value and standard deviation characteristics of the key measurement point assembly deviation are counted to realize 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 deviation sources and 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 means that the deviation source is subject to a normal distribution with a mean of 0 and a standard deviation of 0.25. The deviation source also includes , The statistical prediction characteristics of , , ,

[0160] Table 4

[0161]

[0162] 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.

[0163] 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 in the actual assembly process. 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.

[0164] 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.

[0165] 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.

[0166] ​It should be noted that the Monte Carlo method is used to establish a propeller-shaft system-module assembly rigidity deviation prediction model, statistical calculation of the mean and standard deviation characteristics of the key measurement point assembly deviation is used to realize assembly deviation analysis, and then the mean and standard deviation of the key measurement point assembly deviation are used to calculate the assembly deviation evaluation index. In the embodiment, the assembly deviation evaluation index is the process capability index, which is used to measure the index of whether the deviation distribution meets the design index. The mean of the part feature point deviation is:

[0167]

[0168] The standard deviation is:

[0169]

[0170] The process capability index is:

[0171]

[0172] Wherein, is the mean of the part feature point deviation, 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, is the final deviation result calculated by the i-th simulation, is the upper cut-off of the size deviation, is the lower cut-off of the size deviation.

[0173] Step S306: defining a deviation transmission chain, and constructing a rigidity deviation prediction model based on the deviation transmission chain, the rigidity deviation distribution, and the assembly deviation evaluation index.

[0174] It should be noted that the deviation transmission chain of the ship propeller from the shaft to the power system module and the total assembly under the modular assembly process of the ship is defined, and a rigidity analysis assembly deviation model of the deviation transmission and accumulation of the assembly between the ship propeller, the shaft system and the module in the assembly process is established.

[0175] ​It can be understood that the deviation transmission chain refers to the deviation path from the initial deviation source to the target part or feature through a series of assembly relationships and interactions between parts. In the assembly process of the ship propeller, the deviation transmission chain describes how the manufacturing deviation and installation deviation of each component part are accumulated and finally affect the overall assembly accuracy of the propeller through the assembly sequence and positioning reference. By clearly defining the deviation transmission chain, the transmission and accumulation mechanism of the deviation in the assembly process can be more clearly understood, thereby providing a basis for constructing the rigid deviation prediction model. In constructing the rigid deviation prediction model, the deviation transmission chain, the rigid deviation distribution, and the assembly deviation evaluation index are considered comprehensively, so that the assembly deviation of the propeller can be accurately predicted.

[0176] It is worth noting that the analysis results of the rigid deviation prediction model of the ship modular assembly power shafting stern shaft end face are shown in Table 5, Table 5 is a table of rigid deviation model deviation analysis results of the stern shaft end face, which includes the deviation name and the corresponding rigid simulation results, for example, the rigid simulation result of the stern shaft end face axis radial offset is that the upper cutoff is +2mm, the lower cutoff is -2mm, and the out-of-tolerance rate is 5.30%, 6 6.18mm; the rigid simulation result of the stern shaft end face axis axial offset is that the upper cutoff is +2mm, the lower cutoff is -2mm, and the out-of-tolerance rate is 5.00%, 6 6.13mm; the rigid simulation result of the stern shaft end face and the propeller sealing device axial gap is that the upper cutoff is +2mm, the lower cutoff is -2mm, and the out-of-tolerance rate is 5.12%, 6 6.15mm.

[0177] Table 5

[0178]

[0179] In the embodiment, the number of simulations and the parameter range 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 rigidity deviation distribution of the propeller under different combinations of manufacturing deviation and installation deviation, the deviation source is randomly sampled based on the rigidity deviation distribution by using a random number generator and the deviation analysis is performed to obtain an 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 rigidity deviation prediction model is constructed based on the deviation transmission chain, the rigidity deviation distribution and the assembly deviation evaluation index. The simulation and analysis of the assembly deviation are performed by introducing the Monte Carlo method, the manufacturing deviation and the installation deviation of each part and the interaction thereof in the assembly process are fully considered in the simulation process, the actual assembly situation can be more truly reflected, and the rigidity deviation prediction model can be accurately constructed. Further, the prediction ability of the assembly precision of the ship propeller is effectively improved.

[0180] 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 be referred to the above description, and the subsequent will not be described in detail. On this basis, please refer to Figure 8 , step S40 further includes steps S401-S404:

[0181] Step S401: performing finite element simulation on the rigidity deviation prediction model, simulating the flexible deformation and stress distribution of the propeller in the working state by applying the self-weight of the part and the external load to obtain the finite element simulation result.

[0182] It should be noted that the flexible deformation deviation in the finite element method (FEA) includes the unbalanced mass distribution of the rotating parts such as the propeller and the shaft system due to manufacturing or wear, and the non-uniform load such as the assembly load and the constraint, including the self-weight of the bearing part, the clamping force applied by the clamp as a concentrated force or distributed force in the assembly process, the pre-tightening force of the bolt connection and the connection force when the modules are docked. The flexible key node deformation deviation of the key points of the part in the assembly process under the action of the clamping force, the connection force and the self-weight is quantified and parameterized, and is integrated into the rigidity deviation prediction model obtained by preliminary analysis.

[0183] In a specific implementation, the model is subjected to finite element simulation in finite element software, the component self-weight and external load are applied, the flexible deformation and stress distribution generated by the propeller and shafting and installation module in the working state are simulated, 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 applied: the propeller shaft end is fixedly supported through the hull module, rotation constraint is performed at the bearing, the load conditions include the self-weight 2.5 kN·m of the shafting and module and the engineering load simulation propelling force 500 kN acting in the axial direction, the transverse load 200 kN acting on the propeller blade, and the embodiment is not specifically limited in this regard.

[0184] Step S402: determining the measurement key point deformation data based on the finite element simulation result.

[0185] It should be noted that the rigid deviation prediction model is corrected using the finite element technology, after the finite element analysis, the deformation field and node displacement on the assembled part are extracted, and the measurement key point deformation data can be obtained.

[0186] In a specific implementation, if the maximum deflection displacement of the shafting stern end face free end relative to the model center line 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.

[0187] It should be noted that the flexible deviation prediction influencing factors are identified, quantified and characterized using the finite element method, so as to correct the rigid deviation prediction model, the influencing factors are characterized using the spinor model, and the quantification is performed using the finite element key node analysis. 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 self-weight and external load, the relative displacement and rotation between key nodes are used as node coordinates to describe the deformation of the structure, the deformation of the finite element analysis is integrated into the assembly deviation, the discrete node displacement of each component key mating surface is determined, based on the characterization requirements and sampling frequency, two mating planes of the contact surface need to be discretized as grids, the deformation of the nodes in the grid can be obtained from the finite element analysis result, wherein the sampling points refer to the center points and boundary points defined in the flexible model of the finite element analysis deviation surface, and the finite element analysis result matrix is represented as follows:

[0188]

[0189] wherein, is the number of mating surfaces ( ), is the number of sampling points on each surface defining the flexible deviation, is the matrix composed of the flexible deformation of the th surface, and The first On the surface the first The X, Y, and Z coordinate values ​​of each sampling point.

[0190] By integrating key flexible deviations into a rigid model, a deviation prediction model for a rigid-flexible coupled system is established. The establishment of this model considers manufacturing deviations and assembly deformation factors, constructing a model for the transmission and accumulation of assembly deviations in a rigid-flexible coupled system. During the propeller-shaft-module assembly process, multibody dynamics and the finite element method are used. The motion of the flexible body is decomposed into the motion of the reference coordinate system describing the rigid body motion and the displacement of the nodes relative to the reference coordinate system describing 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 simplify the large-range rigid motion and small-amplitude elastic deformation of the flexible body under applied loads and self-weight. Based on the displacement of each node in the simplified model... and corner This involves establishing the equations of motion for rigid body systems and the modal dynamics equations for the elastic deformation of flexible bodies. Specifically, it uses a screw model composed of relative radial and angular deviations to describe the algebraic equations describing the displacement relationship between components. The predicted deviation values ​​are then converted into a system of differential algebraic equations to construct a deviation prediction model for a rigid-flexible coupled system. For example, this involves analyzing the center of the mating surface between shaft end A and shaft end B at the coupling, expressed using screw parameters. Planar deviation:

[0191]

[0192] in, The 6x1 column vector representing the deviation, i.e., the displacement spinor. These represent the minute translations of the rigid body about the X, Y, and Z axes of the reference coordinate system, respectively. These represent the minute rotations (in radians) of the rigid body about the X, Y, and Z axes of the reference coordinate system, respectively.

[0193] The relative radial deviation of points AB is:

[0194]

[0195] in, The relative radial deviation between A and B, The displacements of point A in the Y and Z directions are... The displacements of point B in the Y and Z directions are given.

[0196] Using finite element key element characterization, the deviation of the deflection angle (small angle approximating relative nodal angle) of the two component axes in the YZ plane is:

[0197]

[0198]

[0199] wherein, 、 is the rotation angle of the node in the plane of the axis, the rotation angle of the node around the X axis, and the rotation angle of the node around the X axis, is the rotation angle component of the node.

[0200] Step S403: calculating the part stiffness matrix based on the measurement key point deformation data.

[0201] It should be noted that the part stiffness matrix is a matrix used to describe the ability of the part to resist deformation when subjected to external force. In finite element analysis, by calculating the deformation of the part under a certain load, the stiffness matrix of the part can be deduced. 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.

[0202] In a specific implementation, based on the measurement key point deformation data, combined with the mechanical principles in finite element analysis, the 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 of the part under unit load, so that the rigidity and deformation characteristics of the part can be comprehensively evaluated.

[0203] In one possible implementation, step S403 can include: determining key feature points based on the measurement key point deformation data, wherein there are deviation sources affecting assembly quality at the key feature points; applying a unit force opposite to the deviation direction on the finite element nodes corresponding to the key feature points 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 the flexibility matrix of the part based on the displacement response matrix; and determining the part stiffness matrix based on the flexibility matrix of the part.

[0204] It should be noted that there are deviation sources affecting assembly quality at each key feature point. If there are N key feature points, there are N deviation sources. A unit force is applied to the finite element nodes of the Nth key feature point in the finite element model, and the displacement response of the Nth key feature point is calculated and expressed in vector form as:

[0205] ​​​​

[0206] Then when in the first Apply force to key feature points hour, The displacement response vectors of the key feature points are:

[0207]

[0208] Apply force at each key feature point ,but The matrix composed of the displacement response vectors of the key feature points is:

[0209]

[0210] in, The flexibility matrix represents the part's stiffness matrix. The relationship between the part's stiffness matrix and flexibility matrix is ​​as follows:

[0211]

[0212] Step S404: Based on the stiffness matrix of the parts and the finite element simulation results, determine the deviation of each part under flexible deformation and obtain the flexible deviation data.

[0213] It should be noted that in the 3DCS model, the flexible deviation is applied to the corresponding nodes or feature points, and the deformation value of the measured point is used to compensate for the rigid deviation, thus obtaining the coordinate displacement of the relevant point after deformation and the stiffness matrix. The flexible deviations generated by the force applied to each key feature point when each corresponding point in the characterization column produces a unit displacement are combined with the original geometric tolerances and applied to the assembly process.

[0214] In practical implementation, the deviation transmission process during assembly is modeled as a whole. The formula for integrating rigid-flexible coupling deviations in modular ship assembly is as follows:

[0215]

[0216] in, For measurement points The total deviation displacement matrix, For assembly steps The cumulative displacement, For assembly steps Assembly displacement caused by positioning and coordination deviations. To determine the positioning displacement of the part itself. This is the displacement due to assembly deviation. The goal is to obtain the flexible deviation displacement caused by gravity and load factors through finite element calculation.

[0217] like Figure 9As shown, Figure 9 The overall flowchart for constructing the rigid-flexible coupling deviation prediction model, the overall process of constructing the rigid-flexible coupling deviation prediction model includes: ship propeller-shaft system-modular assembly deviation transmission model construction; using the Monte Carlo method to predict the rigid assembly model deviation of the submarine propeller-shaft system-modular assembly; based on the finite element method (FEA) to perform flexible assembly deviation influence analysis calculation; rigid-flexible coupling deviation prediction model establishment for ship propeller-shaft system-modular assembly.

[0218] In this embodiment, the rigid deviation prediction model is simulated by finite element simulation, the flexible deformation and stress distribution of the propeller in the working state are simulated by applying the part self-weight and external load, and the finite element simulation result is obtained; the measurement key point deformation data is determined based on the finite element simulation result; the part stiffness matrix is calculated based on the measurement key point deformation data; the deviation of each part under flexible deformation is determined based on the part stiffness matrix and the finite element simulation result, and the flexible deviation data is obtained. Through finite element simulation analysis and combination of the rigid deviation prediction model, the accurate prediction of the flexible deformation deviation in the assembly process of the ship propeller is realized, not only the manufacturing deviation is considered, but also the deformation factor in the assembly process is integrated, thereby improving the prediction accuracy of the assembly precision.

[0219] For example, in order to help understand the implementation process of the assembly deviation prediction method based on the ship propulsion system obtained after the above embodiment one, please refer to Figure 10 , Figure 10 A detailed flowchart of assembly deviation prediction of the assembly deviation prediction method based on the ship propulsion system is provided, specifically: feature decomposition is performed on the part manufacturing data, a non-ideal surface is constructed, and a real geometric model of the part is generated by combining the non-ideal surface with the ideal geometric model of the part; a displacement rotation model is constructed according to the real geometric model of the part; the non-ideal surface deviation is obtained based on the displacement rotation model, and the assembly deviation is obtained based on the displacement rotation model combined with the modular assembly constraint information; the deviation transmission model is constructed according to the non-ideal surface deviation and the assembly deviation; the rigid deviation prediction model is established by simulating the deviation transmission model through the Monte Carlo method; the rigid-flexible coupling deviation model is corrected based on the rigid deviation prediction model and the rigid-flexible material parameter information, and then the model is optimized to obtain the rigid-flexible coupling deviation prediction model; the deviation prediction is performed through the rigid-flexible coupling deviation prediction model using the finite element method according to the assembly product, the assembly process and the assembly environment.

[0220] It should be noted that the above examples are only used to understand the present application and do not constitute a limitation on the assembly deviation prediction method based on the ship propulsion system of the present application, and more forms of simple transformation based on this technical concept are within the protection scope of the present application.

[0221] The application further provides an assembly deviation prediction device based on a ship propulsion system, which comprises:

[0222] An acquisition module is configured to acquire part manufacturing data, actual working conditions and load distribution information of a ship propeller.

[0223] A construction module is configured to construct an assembly deviation transmission model based on the part manufacturing data.

[0224] A simulation module is configured to simulate by a Monte Carlo method based on the deviation transmission model, and construct a rigid deviation prediction model, which is used to predict the cumulative deviation of a propeller composed of multiple rigid parts after assembly.

[0225] An analysis module is configured to perform flexible assembly deviation analysis on the rigid deviation prediction model based on a finite element method, and obtain flexible deviation data.

[0226] 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.

[0227] A prediction module is configured to predict by the rigid-flexible coupling deviation prediction model according to the actual working conditions and load distribution information, and obtain the overall assembly deviation of the ship propeller.

[0228] The assembly deviation prediction device based on the ship propulsion system provided by the application adopts the assembly deviation prediction method based on the ship propulsion system in the above embodiment, and can solve the technical problem of low assembly deviation prediction precision of the prior art. Compared with the prior art, the assembly deviation prediction device based on the ship propulsion system provided by the application has the same beneficial effects as the assembly deviation prediction method based on the ship propulsion system provided by the above embodiment, and other technical features in the assembly deviation prediction device based on the ship propulsion system are the same as the features disclosed in the above embodiment method, which will not be described here.

[0229] The application provides a ship propeller, which is applied to the assembly deviation prediction method based on the ship propulsion system as described above.

[0230] The application provides a computer-readable storage medium having computer-readable program instructions (i.e., a computer program) stored thereon, which are used to execute the assembly deviation prediction method based on the ship propulsion system in the above embodiment.

[0231] The application further provides a computer program product comprising a computer program, which, when executed by a processor, implements the steps of the assembly deviation prediction method based on the ship propulsion system as described above.

[0232] The computer program product provided in the application can solve the technical problem of low prediction accuracy of assembly deviation in the prior art. Compared with the prior art, the computer program product provided in the application has the same beneficial effects as the assembly deviation prediction method based on the ship propulsion system provided in the above-mentioned embodiments, and will not be described here.

[0233] The above-mentioned is only part of the embodiments of the application, and does not limit the patent scope of the application. Any equivalent structural transformation, direct / indirect application in other related technical fields based on the technical concept of the application and the content of the specification and drawings are included in the patent protection scope of the application.

Claims

1. A method for predicting assembly deviations based on ship propulsion systems, characterized in that, The method includes: Acquire manufacturing data, actual operating conditions, and load distribution information for ship propulsion components; An assembly deviation propagation model is constructed based on the manufacturing data of the aforementioned components. Based on the aforementioned deviation transmission model, a rigid deviation prediction model is constructed by performing simulations using the Monte Carlo method. This rigid deviation prediction model is used to predict the cumulative deviation of a thruster composed of multiple rigid parts after assembly. The rigid deviation prediction model is analyzed for flexible assembly deviation using the 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. The overall assembly deviation of the ship propeller is obtained by predicting the deviation based on the actual working conditions and load distribution information using the rigid-flexible coupling deviation prediction model.

2. The method as described in claim 1, characterized in that, The assembly deviation propagation model constructed based on the component manufacturing data includes: Based on the manufacturing data of the components, feature decomposition is performed to obtain feature vectors of multiple components; A non-ideal surface is constructed based on the feature vectors of each part, and the non-ideal surface is used to simulate the actual surface deviations generated by the parts during the manufacturing process; Construct a real geometric model of the part based on the non-ideal surface and the ideal geometric model of the part; Obtain the assembly sequence and positioning datum of the parts, and determine the manufacturing deviation and installation deviation based on the actual geometric model of the parts, the assembly sequence of the parts, and the positioning datum; The deviation propagation relationship is determined based on the manufacturing and installation deviations. An assembly deviation transmission model is constructed based on the aforementioned deviation transmission relationship. This model is used to simulate the transmission and accumulation of deviations of various parts during the assembly process.

3. The method as described in claim 1, characterized in that, The method of constructing a rigid deviation prediction model based on the deviation propagation model using the Monte Carlo method includes: Set the number of simulations and parameter range, and based on the deviation propagation model, randomly generate the manufacturing deviation and installation deviation of each part in each simulation; Based on the manufacturing and installation deviations, the assembly process is simulated using the Monte Carlo method to calculate the cumulative deviation of the thruster in each simulation. Statistical analysis was performed on the cumulative deviation of the thruster in each simulation to obtain the rigidity deviation distribution of the thruster under different combinations of manufacturing and installation deviations. Based on the rigid deviation distribution, a random number generator is used to randomly sample the deviation sources and perform deviation analysis to obtain assembly deviation samples. The assembly deviation evaluation index is calculated based on the assembly deviation sample, and the assembly deviation evaluation index is determined according to the statistical characteristics of the assembly deviation. Define a deviation transmission chain, and construct a rigid deviation prediction model based on the deviation transmission chain, the rigid deviation distribution, and the assembly deviation evaluation index.

4. The method as described in claim 3, characterized in that, The assembly process is simulated using the Monte Carlo method based on the manufacturing and installation deviations, and the cumulative deviation of the thruster in each simulation is calculated, including: Based on the manufacturing and installation deviations, calculate the displacement rotation of the deviation source during the assembly process; Construct a sensitivity matrix, which is used to characterize the degree of influence / contribution coefficient of each deviation source on the cumulative deviation of the thruster; The cumulative deviation of each component or feature in the thruster is determined based on the displacement spin and the sensitivity matrix; The cumulative deviation of the thruster in each simulation is calculated based on the cumulative deviation of each part or feature in the thruster.

5. The method as described in claim 1, characterized in that, The flexible assembly deviation analysis based on the finite element method on the rigid deviation prediction model yields flexible deviation data, including: Finite element simulation was performed on the rigid deviation prediction model. By applying the self-weight of the part and external loads, the flexible deformation and stress distribution of the propeller under working conditions were simulated, and the finite element simulation results were obtained. Determine the deformation data of key measurement points based on the finite element simulation results; Calculate the stiffness matrix of the part based on the deformation data of the key measurement points; Based on the stiffness matrix of the parts and the finite element simulation results, the deviation of each part under flexible deformation is determined, and the flexible deviation data is obtained.

6. The method as described in claim 5, characterized in that, The calculation of the part stiffness matrix based on the deformation data of the measured key points includes: Key feature points are determined based on the deformation data of the measured key points, wherein there are deviation sources affecting assembly quality at the key feature points; A unit force opposite to the direction of deviation is applied to the finite element node corresponding to the key feature point to obtain the displacement response; Construct a displacement response vector for each key feature point based on the displacement response and the unit force; A displacement response matrix is ​​generated based on the displacement response vectors of each of the key feature points. The compliance matrix of the part is determined based on the displacement response matrix; The stiffness matrix of the part is determined based on the flexibility matrix of the part.

7. The method as described in claim 1, characterized in that, The construction of the rigid-flexible coupling deviation prediction model based on the flexible deviation data and the rigid deviation prediction model includes: The flexible deviation data is converted into a displacement field form to obtain the nodal displacement data; Based on the node displacement data and the rigid deviation prediction model, deviation analysis is performed to obtain the rigid-flexible coupling deviation distribution. Based on the rigid-flexible coupling deviation distribution simulation, the influence of different loads on the deviation under actual working conditions is obtained, and the deviation mapping relationship in the rigid-flexible coupling deviation prediction model is obtained. A rigid-flexible coupling deviation prediction model is constructed based on the aforementioned 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: The acquisition module is used to acquire manufacturing data, actual operating conditions, and load distribution information of ship propulsion components; The construction module is used to build an assembly deviation transmission model based on the manufacturing data of the components; The simulation module is used to perform simulations based on the deviation transmission model using the Monte Carlo method, and to construct a rigid deviation prediction model. The rigid deviation prediction model is used to predict the cumulative deviation of a thruster composed of multiple rigid parts after assembly. The analysis module is used to perform flexible assembly deviation analysis on the rigid deviation prediction model based on the finite element method to obtain flexible deviation data. The construction module is also used 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 propeller based on the actual working conditions and load distribution information using 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 as described in 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, which, when executed by a processor, implements the assembly deviation prediction method based on a ship propulsion system as described in any one of claims 1 to 7.

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