Method and device for free-form surface measurement based on reference calibration plate to correct pose

Abstract

The invention belongs to the field of free-form surface measurement and machine vision measurement, relates to a free-form surface measurement method and device for correcting a pose based on a reference calibration plate, solves the problems of rotary table rotation errors, mechanical arm spatial motion errors and point cloud registration references and the like existing in a large free-form surface measurement process, and can be used for improving the detection precision of the surface topography of free-form surfaces. According to the free-form surface measurement method and the device forcorrecting the pose based on the reference calibration plate provided by the invention, a free-form surface is mounted on the surface of a reference calibration plate, while the surface height of thefree-form surface is collected by a free-form surface measurement sensor, an image of the reference calibration plate is collected through a camera, and a feature point of the image of the referencecalibration plate is extracted, so that a transformation matrix of the reference calibration plate relative to the reference calibration plate camera is calculated, and then the pose change of the measured free-form surface relative to the free-form surface measurement sensor is obtained. The problems of the rotary table rotation errors and the mechanical arm spatial motion errors and the like inthe free-form surface measurement process are solved, a reference is provided for the free-form surface multi-pose measurement, the motion errors in the measurement process are separated, and the high-precision detection of the free-form surface is realized. Meanwhile, a reference of the measured free-form surface height data fusion and data splicing is provided, so that the fitting precision of the free-form surface is improved.

Description

technical field [0001] The invention belongs to the fields of free-form surface measurement and machine vision measurement, and relates to a free-form surface measurement method and device for correcting poses based on a reference calibration plate, which solves the rotation error of a rotary table and the space motion error of a mechanical arm in the measurement process of a large-scale free-form surface and point cloud stitching benchmarks. [0002] technical background [0003] Free-form surface is the most complex and frequently encountered surface in engineering. In aviation, shipbuilding, automobile, home appliance, machinery manufacturing and other departments, the shape of many parts, such as the surface of aircraft wing or automobile shape, and the surface of mold workpieces, are free surface. The shape of free-form surfaces can be roughly divided into two types or composed of these two types: one type is composed only of elementary analytic surfaces such as planes,...

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Problems solved by technology

[0008] The invention belongs to the field of free-form surface measurement, and relates to a free-form surface measurement method and device for correcting poses based on a reference calibration plate, which solves problems such as the rotation error of a rotary table and the space motion error of a mechanical arm in the free-form surface measurement process

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