A Skinning Process Model Correction Method Based on Workpiece Point Cloud Model

Abstract

The invention proposes a skinning process model correction method based on a workpiece point cloud model. After processing the point cloud of the workpiece and referring to the design model for equal length cutting, align it with the design model. Create a reference line and a reference plane group, intersect the reference plane group with the point cloud model of the workpiece and the design model to obtain a cross-section line group, and then discretize the cross-section line group to obtain two corresponding discrete point groups, establish a calculation formula for discrete curvature, and calculate The discrete curvature of each discrete point is calculated by the compensation formula to obtain the discrete curvature value of the compensated point. The position of the discrete point on the design model section line and the discrete curvature value of the discrete point on the process model section line are used to obtain the position of the discrete point after compensation, and the compensated section line is obtained by fitting. Finally, a surface based on the compensated section line set is generated, and a corrected process model is obtained. The invention can carry out secondary correction on the inaccurate skin technology model, and quickly and accurately modify the technology model of the skin parts.

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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