Reading recognition and measurement method of pointer instrument based on machine vision system

Abstract

The invention relates to a reading recognition measurement method for a pointer-type instrument based on a machine vision system, and belongs to the technical field of instrument measurement. The method comprises the steps: building a visual imaging system model for a plurality of pointer-type instruments; employing a CCD camera plane calibration method to calibrate the internal parameters and distortion parameters of a camera and the external parameters of a pointer-type instrument dial plate; rotating an pointer-type instrument image to a position where the pointer-type instrument image is parallel to the pointer-type instrument dial plate through the external parameters of the pointer-type instrument dial plate; translating each pointer-type instrument image to a position nearby an optical center, and extracting the scale and the position of a pointer and the center of each pointer-type instrument image through the image processing technology; and obtaining the reading of the pointer-type instrument through an angle method. The method is advantageous in that the method employs the visual measurement technology, eliminates the perspective projection distortion through image rotation, improves the measurement precision, and is suitable for the measurement of the reading of a plurality of instruments at the same time through one camera. The method achieves the high-precision intelligent detection, improves the reading efficiency of the instruments, and improves the calibration efficiency of the camera.

Description

technical field [0001] The invention relates to the technical field of meter measurement, in particular to a method for recognizing and measuring pointer meter readings based on a machine vision system. Background technique [0002] Generally, instruments can be divided into two categories: pointer instruments and digital instruments. Among them, the measured value displayed by the digital instrument is digital, so it has the characteristics of simple, intuitive and accurate reading; The dial has simple internal structure, convenient maintenance, low manufacturing cost, no need for operating power supply, strong anti-interference ability, and has the characteristics of irreplaceable digital instruments, such as household water meters, car speed indicators, pointer ohmmeters, etc. Therefore, from the perspective of the demand for pointer meters in scientific experiments and industrial production, pointer meters have a huge market demand. [0003] At present, most of the poin...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a method for recognizing and measuring pointer instrument readings based on a machine vision system, which solves the above-mentioned problems existing in existing image recognition and detection methods

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