Skin process model correction method based on workpart point cloud model

Abstract

The invention provides a skin process model correction method based on a workpart point cloud model. And performing point cloud processing on the workpart, performing equal-length cutting by referringto the design model, and aligning with the design model. Creating a reference line and a reference plane group, the reference plane group is intersected with the point cloud model and the design model of the workpart to obtain a section line group, then the section line group is discretized to obtain discrete point groups corresponding in pairs, a discrete curvature calculation formula is established, the discrete curvature of each discrete point is calculated, and the discrete curvature value of the compensated point is calculated through a compensation formula. And the positions of the compensated discrete points are obtained by utilizing the positions of the discrete points of the section line of the design model and the discrete curvature values of the discrete points of the section line of the process model, and the compensated section line is obtained through fitting. Finally, a curved surface based on the compensated section line set is generated, and a corrected process modelis obtained. According to the method, secondary correction can be carried out on the inaccurate skin process model, and the process model of the skin part can be quickly and accurately modified.

Description

technical field [0001] The invention relates to a skinning process model correction method based on a workpiece point cloud model, which is applied to the process model correction of complex variable curvature skin parts, and uses the corrected process model as the basis for the design and manufacture of skin molds, belonging to aircraft manufacturing technology field. Background technique [0002] Skin parts are a type of typical aircraft parts, which are the thin plate parts that constitute the aerodynamic shape of the aircraft and the foreskin of the internal structural frame, generally made of aluminum alloy or composite materials. Generally, according to its geometric shape, it can be divided into single curvature skin and double curvature skin. The complexity lies in the fact that the curvature of the surface is mostly variable curvature, and the curvature changes irregularly. If any section crosses the surface of the part to intersect the shape surface, each intersect...

AI Technical Summary

Problems solved by technology

Traditionally, the forming die is designed according to the outer surface of the skin part. Due to the large springback of the skin part, this mold design method makes it difficult to meet the precision requirements after the part is formed.

Among the springback compensation process model modeling methods currently applied, the distance compensation method and the equal arc length arc fitting method are the most common. Among them, the distance compensation method is the simplest, but it cannot guarantee that the size of the part after compensation still meets the design requirements, and etc. The compensation method of arc length and arc fitting has a large deviation in the process of fitting the arc, and often requires multiple correction iterations to obtain accurate results

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