Positioning target, visual measurement system and method for acquiring flatness

Abstract

The invention provides a positioning target, a visual measurement system and a method for acquiring flatness based on the positioning target and the visual measurement system. The positioning target comprises an active light-emitting lamp source, at least three high-precision spheres are arranged at the bottom of the lamp source and are not located on the same straight line, and a control mainboard is installed on the lamp source and used for sending a measurement instruction according to set time. The visual measurement system adopts the positioning target. The method for acquiringthe flatness comprises the following steps of fixing the visual measurement system, placing the positioning target at a to-be-measured part, and detecting the central coordinate of the positioning target throughthe visual measurement system,moving the positioning target to collect m points at the to-be-measured part and fitting to obtain a reference plane S',and continuously moving the positioning target toacquire the coordinate Pi of the ith point, and calculating the vertical distance from the coordinate Pi of the ith point to the virtual plane S'to serve as the plane deviation degree of the currentmeasurement point. The method has the advantages of high repeatability, high precision, high efficiency, interference resistance, light and small size, convenience in carrying and operation and the like.

Description

technical field [0001] The invention belongs to the technical field of visual measurement, and in particular relates to a positioning target, a visual measurement system and a method for obtaining flatness based on the positioning target and the visual measurement system. Background technique [0002] The marking point of visual measurement is a key technology in the field of machine vision. The marking point is installed on the measurement or tracking object, and the position and attitude of the object can be obtained quickly and accurately through image processing technology. Marking points are usually divided into passive marking points that rely on reflective light and active marking points that emit light. However, the accuracy of these two types of marking points cannot reach the micron level. It is necessary to expand the positioning accuracy to the micron level to achieve ultra-precise positioning. It has always been a technical problem faced by this area. [0003] ...

AI Technical Summary

Problems solved by technology

Marking points are usually divided into passive marking points that rely on reflective light and active marking points that emit light. However, the accuracy of these two types of marking points cannot reach the micron level. It is necessary to expand the positioning accuracy to the micron level to achieve ultra-precise positioning. It has always been a technical problem in this field

[0003] According to the GB / T11337-2004 standard, the existing flatness measurement mainly includes direct measurement methods (gap method, indicator method, optical axis method, interference method, liquid level method) and indirect measurement methods (level method, self-calibration meter method) , pedometer method and table bridge method), the main disadvantages of these measurement methods include: (1) the measured plane area is limited, generally not more than 1m*1m; (2) lack of plane coordinates, usually only plane can be measured Deviation, the coordinates of the measured points on the plane need to be manually calculated or spliced; (3) The measurement efficiency is low, requiring a lot of preparation and adjustment work, the measurement process needs manual adjustment, and the efficiency is low; (4) It is not easy to digitize, and most of them cannot All measurement data are automatically recorded, and 3D splicing is required to form a 3D flatness report

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