RU2308763C2 - Method for automatic construction of three-dimensional geometric model of product in geometric modeling system - Google Patents

Abstract

FIELD: information technology, possible use for designing complex technical products.

SUBSTANCE: method includes selecting data of computer mathematical model, for usage in construction of three-dimensional geometric model of product, series of automatic construction operations is set, data selected by user is read, aforementioned data is transformed to values of geometric parameters of product, from a previously created database, three-dimensional geometric primitive models are extracted, changes of their parameters are altered in accordance with computer mathematical model data, dynamic construction is performed for elements of product which are absent in database, resulting three-dimensional geometrical models of product elements are placed into three-dimensional geometrical models of product assembly and connections are applied, which hold the position of each element of the product in assembly.

EFFECT: reduction of time and computing resources.

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Description

The invention relates to the field of information technology and can be used in the design of complex technical products on a computer. The implementation of the invention can significantly reduce the time and computational resources spent in the design of such products.

A known method of constructing a three-dimensional geometric model (TGM) of a product used in a graphical browser system for displaying and controlling a computer model, also called a geometric modeling system (US patent No. 5815154 "Graphic browser system for displaying and controlling a computer model" of September 29, 1998) , which provides the user with the opportunity to build a product model on the computer screen and manage this model using keyboard commands, mouse / cursor combinations, and other environments input properties. Changes in the model are displayed on the screen image of the model at the moment when the user makes changes or in response to the actions of the user who sends a special command to update the screen image of the model. In this method, a separate representation of a computer model is used in the form of a graphic image of a three-dimensional model in one part of the screen and the pictograms of its constituent elements in another part of the screen, which are displayed in a certain order associated with the order of creation of model elements and the interconnections of the elements with each other. At the same time, the user can access all the characteristics of the model using both a graphical representation and pictograms of structural elements.

This method, with all its advantages, has significant drawbacks when it is used in the design process on a computer, when for each new version of the designed product a large number of models of structural elements are constructed, in many cases having a similar shape. In this case, the user needs to manually build computer models of product elements and the product itself each time, performing many typical operations in the construction process.

Therefore, the objective of the invention is to eliminate the above disadvantages, namely: automatic construction of TGM elements of products and the products themselves in the design process based on a given sequence of operations.

This task is achieved by the fact that in the method of automatically building the TGM of the product in a geometric modeling system that provides the user with the opportunity to build the product model on the monitor screen and control this model using keyboard commands, mouse / cursor combinations and other input tools, while changes to the model are displayed on the screen image of the model at the moment when the user makes changes or in response to the action of the user who sends a special command to update the screen of the image, according to the invention, the construction of the product model is carried out using tools for specifying, selecting and executing a sequence of operations for automatically building the TGM of the product according to the computer mathematical model (KMM), first select the KMM data that will be used to build the TGM, and set the sequence automatic construction operations using the KMM data selection tool, then the user selected KMM data is read using the automatic h data of KMM numerical data, then the selected data is converted to the geometric parameters of the TGM elements of the product using the means of automatic conversion of KMM numerical data, and then three-dimensional geometric models-primitives are extracted from the previously created database using the means of interaction with the specified database, change the values of their parameters in accordance with the CMM data using the means for changing the values of the parameters of three-dimensional geometric models of primitive divisions and perform dynamic construction of the TGM of those product elements whose three-dimensional geometric model primitives of which are absent from the database using the means of dynamically building the TGM of the structural element, place the obtained TGM of the product elements in the TGM of the product assembly and impose mates fixing the positions of the TGM of each product element in the assembly, using the automatic construction tool TGM products in the form of an assembly consisting of TGM product elements.

The essence of the proposed method is that for the automatic construction of the TGM of the product, the sequence of necessary operations is set once, and then automatically performed for each new version of the product. The predetermined sequence of operations is used for various versions of the product model having the same design, but different geometric parameters, while the proposed method completely eliminates the manual input of TGM data, which is a source of potential errors in the case when a TGM product with hundreds of parameters is built.

The attached drawing shows a diagram of the functioning and interaction of the tools included in the method for automatically building a TGM product in a geometric modeling system. The described tools are programs, therefore they are also called software modules. The following notation is used in the above diagram:

1 - computer mathematical model of the product (KMM);

2 - a means for the user to select those KMM data that will be used to build the TGM and specify the sequence of construction operations (SVDM);

3 - a means of automatic reading of numerical data of a computer mathematical model (SASHD);

4 - a means of automatically converting the numerical data of the CMM into the values of the geometric parameters of the TGM elements (SAPD);

5 - a tool for automatic construction of TGM in real time (SAPM);

6 - a means of interacting with a database (hereinafter DB) of three-dimensional geometric models of primitives (SRBD);

7 - database of three-dimensional geometric models of primitives (DB);

8 - means for changing the values of the parameters of three-dimensional geometric models of primitives (SIZP);

9 - a means of dynamically building a TGM structural element that is not in the database (SDPM);

10 - a means of automatically building a TGM product in the form of a separate assembly consisting of TGM product parts that are automatically mated (SAPMS);

11 - a system of geometric modeling (SGM).

KMM of a product refers to a program for calculating product parameters and modeling physical processes that occur in a product, which also calculates the geometric parameters of a product (for example, a program for calculating aerodynamic characteristics of a glider allows calculating various geometric parameters: position of bearing surfaces, dimensions of bearing surfaces, glider profile, program calculation of a solid fuel rocket engine allows you to calculate the geometry of the chamber, nozzle block, charge).

A three-dimensional geometric primitive model is a model of a basic structural element that does not include any other elements.

By a means of selection by a user of the data of a computer mathematical model that will be used to build a TGM (SVDM), we mean a software module (program) that allows the user to interactively select the necessary CMM data and set the required sequence of construction operations.

By means of automatic reading of numerical data of a computer mathematical model (SASH) is meant a program module (program) that performs automatic reading of CMM data taking into account the specified location of these data (hard drive of a local computer, local computer network, etc.).

By means of automatically converting the numerical data of a computer mathematical model into the values of the geometric parameters of the TGM elements (SAPD), we mean a program module (program) that converts the numerical data of the CMM into the values of the geometric parameters of the TGM design.

Under the tool for automatic construction of TGM in real time (SAPM) is meant a software module (program) that implements a given sequence of operations of automatic construction, controlling the operation of the VTS, SIZP and SDPM.

A database of three-dimensional geometric primitive models means a previously created database in which three-dimensional geometric primitive models are stored.

Under the means of interaction with the database of three-dimensional geometric models of primitives (SBBD) is meant a software module (program) that converts requests for copying three-dimensional geometric models of primitives to the database format.

Under the means for changing the values of the parameters of three-dimensional geometric models of primitives in accordance with the data of a computer mathematical model (SIZP) is meant a program module (program) that changes the values of the geometric parameters of three-dimensional geometric models of primitives copied from the database.

By means of dynamically building a TGM of a structural element that is not in the database (SDPM), we mean a software module that dynamically constructs a TGM of product elements that are not in the database using the specified sequence of construction operations and the means of the SGM.

By means of automatically building a TGM product in the form of a separate assembly, consisting of TGM product elements that are automatically mated (SAPMS), we mean a software module (program) that automatically builds a TGM product as a separate assembly by adding TGM elements to it product, and the imposition of conjugations (restrictions) on them, fixing their position in the TGM of the product.

The indicated KMM, item 1, is a computer program for mathematical modeling of the designed product, previously developed and functioning independently of the means of automatically building TGM products in the geometric modeling system and the geometric modeling system itself. The automatic construction of the TGM is carried out as follows: first, the user, using SVDM, item 2, selects what data of the computer mathematical model will be used to build the TGM of the product. Then, using the SASHD, item 3, the data of the computer mathematical model selected by the user is automatically read. Using a predefined sequence of construction operations, SAPD, item 4, automatically converts the selected numerical data of the computer mathematical model into the values of the geometric parameters of the elements of the three-dimensional geometric model of the product. If the sequence of operations for automatically constructing a three-dimensional geometric model of the product is not known, then the user must determine it using SVDM, pos.2.

Further, in accordance with the previously selected sequence of construction operations, the TGM of the product is automatically built using SAPM, item 5. At the same time, some of the elements included in the TGM assembly of the product are copied from the database of three-dimensional geometric primitive models through the interaction between the BDS, pos.6, and the database, pos.7, while the values of their geometric parameters are changed in accordance with the values of the CMM data using SIZP, pos.8, and the other part of the TGM of the product elements that are not in the database, is built dynamically using SDPM, pos.9. Then, using SAPMS, item 10, the obtained TGM of the product elements are then placed in the TGM of the product assembly and mates are automatically superimposed on them, fixing the positions of the model of the product element in the assembly. If the sequence of operations required to build the TGM of the product is not defined, then the user needs to determine this sequence once, after which it will be automatically used in the future. All program modules included in the implementation of the method of automatically building a TGM product in a geometric modeling system either work in the SGM, item 11, or interact closely with it, which is shown in the diagram by a dotted block that covers all the described program modules.

A method for automatically building a TGM product in a geometric modeling system is programmatically implemented and used in the design of complex technical products using the example of aircraft components: airframe, engine, gyrocoordinator. The practical application of this method allows to reduce the execution time of a preliminary design of these products, which confirms its effectiveness.

Claims (1)

A method for automatically constructing a three-dimensional geometric model (TGM) of a product in a geometric modeling system, including the user building a product model on the monitor screen and controlling this model using keyboard commands, mouse / cursor combinations, while changes to the model are displayed on the model’s screen image at that moment when the user makes changes or in response to the action of the user sending the command to update the screen image, characterized in that the construction of the model products are carried out using tools for specifying, selecting, and executing a sequence of operations for automatically building a TGM of a product according to computer mathematical model (KMM) data, first, select those KMM data that will be used to build a TGM, and specify a sequence of operations of automatic building using a selection tool KMM data, then the KMM data selected by the user is read using the KMM numerical data automatic reading tool, then the conversion inserting the selected data into the values of the geometric parameters of the TGM elements of the product using the means of automatic conversion of numerical data of the CMM, after which three-dimensional geometric models of primitives are extracted from the previously created database using the means of interaction with the specified database, their parameter values are changed in accordance with the data KMM using means for changing the values of the parameters of three-dimensional geometric models of primitives and perform using means dynam To construct TGMs of the structural element, dynamically construct TGMs of those product elements whose three-dimensional geometric primitive models are missing from the database, put the obtained TGMs of the product elements into the TGMs of the product assembly and impose mates fixing the positions of the TGMs of each product element in the assembly using automatic construction tools TGM products in the form of an assembly consisting of TGM elements of the product.