Length comparison difference value measurement method without accurate positioning

Abstract

The invention discloses a length comparison difference value measurement method without accurate positioning. The length comparison difference value measurement method without accurate positioning comprises steps of determining a standard workpiece, wherein the length of the workpiece is L0, also known as Lab, making a measurement reference plane perpendicular to a measured reference plane, making a laser sensor measure to an a point, obtaining reference data a point (Lma,Xa), rotating the standard workpiece for 180 degrees, making the laser sensor measure to b point (Lmb,Xb), using the above method to establish a relation between the standard workpiece, the length of which is L0, and the a point (Lma,Xa) and b point (Lmb,Xb), using the measurement method to measure data of two points a1, b1 that a workpiece having an unknown length chooses, obtaining data of the a1 point (Lma1,Xa1) and the b1 point (Lmb1,Xb1) through measurement, calculating a length of the workpiece through a following formula: a practical workpiece length La1b1=(Xa1-Xa)+(Lma1-Lma)+(Xb1-Xb)+(Lmb1-Lmb)+Lab. The length comparison difference value measurement method without accurate positioning uses a comparison difference value to calculate, reduces measurement conditions, improves measurement accuracy and improves a measurement speed.

Description

technical field [0001] The invention belongs to the field of non-contact measurement, and in particular relates to a method for measuring length comparison difference based on a laser sensor without precise positioning. Background technique [0002] At present, there are many methods for non-contact measurement of the geometric dimensions of workpieces, such as light curtain measurement method, multi-point measurement method, visual measurement method and so on. [0003] Light curtain measurement method: emit a beam of light from one end of the workpiece to be measured, illuminate the workpiece, and receive light from the other end of the workpiece to measure the size of the workpiece. This method is fast and accurate, and the workpiece does not need to be accurately positioned, as long as the workpiece is within the measurement range. Limited by the width of the measuring light source, the size of the parts detected by this method is limited; limited by the measurement met...

AI Technical Summary

Problems solved by technology

The process of measuring the shape and position tolerance of complex parts by this method is cumbersome and requires specialized personnel to measure, which has low efficiency and high price

[0005] Visual measurement method: A measurement system composed of digital camera, lens, light source, processing software, etc. is used to complete the size measurement of the measured workpiece. The measurement accuracy of this method is affected by changes in lens specifications, resolution, focal length, depth of field, light source, mechanism, etc. , the installation and debugging are more troublesome, the measurement accuracy of the size of the larger workpiece is not high, and the price of the measuring equipment is relatively high

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