Method for quickly positioning feature information based on three-dimensional projection

Abstract

The invention discloses a method for quickly positioning feature information based on three-dimensional projection. The method is implemented by using a visual sensor provided with a camera and a projector, and the visual sensor is fixed at the tail end of a robot or fixed on a station where a to-be-measured object is located. The method comprises the following steps: 1) determining three-dimensional coordinates of a feature mark point in a coordinate system of the to-be-measured object based on standard data; 2) transforming the coordinates of the feature mark point in a projector coordinatesystem through a transformation relationship of the coordinate system of the to-be-measured object-robot coordinate system-sensor coordinate system-projector coordinate system, or through the transformation relationship between a sensor coordinate system of a sensor with a fixed location and the coordinate system of the to-be-measured object; and 3) mapping three-dimensional coordinates onto a projection plane according to the imaging projection principle, obtaining two-dimensional coordinates, generating a projection picture, and projecting the projection picture on the surface of the to-be-measured object to assist manual point attachment. According to the method, no process card is used, the artificial influence can be effectively eliminated, less time is consumed, and the accuracy is high.

Description

technical field [0001] The invention relates to the field of precision measurement, in particular to a fast positioning method for feature information based on three-dimensional projection. Background technique [0002] With the rapid development of high-end advanced manufacturing technology, higher requirements are put forward for the precision measurement technology of geometric quantities, among which the demand for high-density and fine 3D point cloud measurement is a typical problem. High-quality 3D point cloud is the basic data necessary for special and complex geometric tolerance analysis, such as DLM parameter measurement of automobile body characteristic line, aircraft skin rivet surface deviation measurement, ship bending plate surface deviation measurement, etc. The automatic blue-ray scanning system is an automatic precision measurement system that uses blue-ray 3D scanning technology to obtain fine 3D point clouds on free-form surfaces, combined with industrial ...

AI Technical Summary

Problems solved by technology

The current conventional global splicing point setting method is to manually place the splicing point on the corresponding position on the car body against the process card; it takes about 1 hour to manually paste a whole vehicle, and the efficiency is low; the deviation of the placement position depends on the difference in the manual identification position , generally on the order of a few centimeters, in the actual measurement process, the global splicing point will exceed the field of view of the sensor, resulting in the failure of splicing at the measurement position and the need for re-shooting; in addition, the pre-production process card is also a cumbersome work. , how to enable users to identify the position of the global splicing point, and minimize the number of craft cards, this is a job that requires long-term experience accumulation

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