Spatial intersecting curve weld joint structure modeling method based on line structured light vision

Abstract

The invention discloses a spatial intersecting curve weld joint structure modeling method based on line structured light vision. The method comprises the steps of through structured light stripe imageprocessing of a measured weld joint, extracting a stripe single-pixel center line, and constructing a slope change curve of the stripe center line; and based on slope analysis, extracting intersecting curve weld joint point set image features, and building a weld joint curve and two-side curved surface change feature model under a robot base coordinate system through pose transformation and Bspline curve fitting of a robot welding system. An offline weld joint control point pose sequence is formed through time average interpolation, a welding gun coordinate system is constructed according towelding process requirements, and welding gun poses corresponding to the control point sequence are determined. According to the method, the limitation that in the prior art, only the positions of weld joint feature points are represented, and structural feature expression of the curved surfaces around the weld joint is lacked is overcome, so that the constructed curve weld joint structure model has overall characterization reflecting the welding position and posture at the same time, and a basis is provided for follow-up welding track planning and control.

Description

technical field [0001] The invention belongs to the technical field of welding seam detection and welding automation, and in particular relates to a modeling method of space intersecting curve welding seam structure based on line structured light vision. Background technique [0002] In the field of welding engineering practice, there are many intersecting structures of pipe fittings of different shapes, forming complex space intersecting curve welds. The welding processing tasks of such space curves have been widely used in automobiles, ships, petroleum, steel structures, various pressure Among the manufacturing industries such as containers. Due to the variety of spatial curve weld shapes and structures, manual welding is not only labor-intensive and inefficient, but also requires high operational skills for workers, and the welding quality is not easy to guarantee. In recent years, researchers have carried out a lot of useful work on the application of industrial robots ...

AI Technical Summary

Problems solved by technology

[0006] To sum up, the model constructed by the spatial geometry method mainly used at present is not universal, and the influence of uncertain factors such as workpiece processing and assembly errors is ignored.

The modeling based on visual feature detection is mainly limited to the detection of weld feature points, and lacks the detection of the structural features of the workpiece around the weld. A modeling method that comprehensively describes the structural characteristics of curved welds needs to be proposed

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