Device for measuring normal vector at arbitrary point on free-form surface and measuring method thereof

Abstract

The invention provides a device for measuring a normal vector at an arbitrary point on a free-form surface and a measuring method thereof. The device comprises a body fixing assembly and four deflected angle measuring mechanisms. The four deflected angle measuring mechanisms form a cross-shaped structure which is installed on the body fixing assembly. Each deflected angle measuring mechanism comprises angle sensors, contact rods and spherical contacts. The measuring shafts of opposite angle sensors are parallel and the measuring shafts of adjacent angle sensors are vertical. The central line of two opposite spherical contacts is vertical to that of another two opposite spherical contacts. The two central lines are intersected with the central axis of external machining arms. The measuringmethod comprises the steps of: during measurement, marking curves on the free-form surface twice respectively through four spherical contacts to form an orthogonal plane; correcting the angle of the central axis of external machining arms; and further obtaining the normal vector of the point to measure. With adoption of the method provided by the invention, less measuring data points are employedwithout the complex process of surface fitting and the precision of the device meets the actual requirements when curved surface with greater curvature is measured so that the invention is convenientto use.

Description

technical field [0001] The invention relates to the technical field of measurement and detection, in particular to a device for measuring a normal vector at an arbitrary point on a free-form surface and a measurement method thereof. Background technique [0002] In the field of mechanical processing, flexible hole making is an important part of flexible drilling and riveting of thin-walled structures. The verticality of the hole position of the riveting point directly affects the riveting quality of the panel. The complex application field puts forward high requirements on the normal alignment of flexible hole making. Since the skin mostly adopts a riveted structure, the hole quality defect caused by the out-of-tolerance normal precision of the drilling will directly affect the aerodynamic shape of the skin and even the safety performance of the component structure. The aircraft skin is generally very thin and has complex curvature. The normal direction of the hole changes ...

AI Technical Summary

Problems solved by technology

This method is complex to calculate and has a large workload. It often needs to obtain the coordinates of dozens of data points on the surface to obtain high calculation accuracy.

Due to the limitations of measurement technology, work efficiency and the mechanical structure of automatic drilling and riveting equipment, in the actual automatic drilling and riveting process, it is impossible to measure the coordinates of a large number of data points on the surface of the skin panel, which makes this method lose the premise of application and cannot be effective Solve the real-time problem of solving the normal vector of drilling and riveting points in the process of automatic drilling and riveting

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