A Calculation Method of Trimming Points Based on Binocular Vision

Abstract

The invention discloses a method for calculating edge tangent points based on binocular vision, which includes the following steps: binocular vision measurement to obtain three-dimensional edge tangent coordinates; plane fitting to obtain plane I, and projecting the three-dimensional edge tangent coordinates onto the fitting plane I , get N j ;Project the theoretical coordinates and theoretical normal direction of the tangent point onto the plane I, and establish a straight line L: Calculate N j The distance to the straight line L, we get N j ′; Cross product to get vector n″, establish a straight line L′; along the theoretical projection normal direction n′ direction, calculate N j The distance D to L′, according to the D value, the three-dimensional projection point N is calculated according to the preset step size. j Divide into N groups; select the group with the largest D value and the number of points in the group greater than m as the group of the edge tangent point; average the coordinates of all three-dimensional projection points in the group of the edge tangent point to obtain the measurement coordinates of the edge tangent point; The measurement coordinate accuracy of this method can reach tens of microns and the measurement time is at the millisecond level, which can meet the detection requirements of precision processing manufacturing industries such as the automotive industry.

Description

Technical field [0001] The present invention relates to the field of feature detection, and more particularly to a cutting point calculation method based on bicomputer visual. Background technique [0002] With the development of automation technology, the improvement of social productivity is increasingly strict, and the basic principles of product quality are increasing, and the basic principles of manufacturing quality can be concatenated into two categories: 1. Avoid errors - this method utilizes high precision Processing equipment, advanced control structure and high reliability sensor detection mechanism fundamentally improving the quality of the machined parts, but this method is complex, costly, currently has no complete real-time scheme; 2. Error compensation Method - This method is to use modern test technology, the new statistological tolerance method combined with existing engineering control and statistical control methods, study product size distribution characteris...

AI Technical Summary

Problems solved by technology

[0002] With the development of automation technology and the improvement of social productivity, the manufacturing industry has become more and more strict about product quality control. The basic principles of improving manufacturing quality can be summarized into two categories: 1. The method of avoiding errors-this method uses Processing equipment, advanced control structure and high-reliability sensor detection mechanism can fundamentally improve the quality of processed parts, but this method is complicated to operate and expensive, and there is no complete real-time solution at present; 2. Error compensation Method - This method is to use modern testing technology, new statistical tolerance method combined with existing engineering control and statistical control methods to study product size distribution characteristics, analyze the processing status of mold fixtures, and then control and adjust them. This method has attracted more and more attention, and the key technology to implement this method is measurement, which can obtain effective data of the measured object, thus providing the basis for subsequent control methods

[0003] Among the many measured features, trimming point is an important category to be tested. Taking the car body in white as an example, whether the position of trimming point is accurate or not is directly related to the straightness of the edge of the workpiece. The basis for meeting the requirements; the traditional inspection sample rack is a widely used inspection tool in the 1970s. This method is low in cost, but the inspection speed is slow and the accuracy is low (about 0.1mm), which cannot meet the inspection accuracy required by precision instrument manufacturing; Another detection method is to use a three-coordinate measuring machine (CMM) for trimming point detection. Although this method has high precision, the measurement speed is very slow. For space boundary points, only a limited number of points can be measured, and it is impossible to fully describe the space boundary. Geometric dimension features, and the measurement process requires manual intervention, and the measurement results need to be compensated for probe damage and probe radius

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