Development Of Linear Array Image Acquisition And Size Measurement System

With the continuous development of computer technology and optical technology,the automatic detection of modern enterprise product has obtained rapid development.The detection requirements for the size in the field of industry are becoming higher andhigher both on measuring accuracy and measuring speed. The traditional detectionmethods are difficult to meet the requirements of modern factory, and as a newmeasurement method, computer technology has been developing fast due to its highprecision and speed. The precision measurement based on computer has got widely usedin the world because of its quickness, non-contact and high precision.This article introduces several measurement methods of linear array sensor andanalyzes the application range of these methods. The measuring principle of this systemis analyzed in detail. The structure of the sensor and pixel unit are analyzed on the basisof the linear array image sensor, and according to the structure features and thecharacteristic of image information by acquisition module, a sub-pixel high precisionmethod based on linear interpolation of light intensity is proposed. First, the pixel islocated accurately. Combined with the characteristic of the sensor pixel, the systemcalibration is realized and the geometry size is measured. Then the calibration andmeasurement method of the system are studied. The measurement accuracy and theinfluence caused by non stability of light source and temperature drift of the sensor arealso analyzed. In theory this method can realize size measurement with unbiasedlocation and high precision. In theory this method can realize unbiased location and thesize of the high precision measurement.The measurement platform is set up based on the measurement principle, whichincludes the selection of light source, the design of data acquisition module and thechoice of support platform. Acquisition card is the key component in this system toachieve high precision measurement, which is mainly used to complete the datacollection and transmission. Its performance determines whether the collected imagesignal accurately reflects the size of the measured object. This paper in detail introducesthe design process of the acquisition card, including amplifier circuit, filter circuit,analog-to-digital conversion, USB transfer module design, etc. And the linear arrayimage acquisition module is developed.In this paper, the measurement software system is designed, including the software design of sensor driver and USB driver. A real-time measurement system for size isreceived with LABVIEW. This system mainly includes linear array image acquisition,USB image signal transmission, system calibration and measurement module, etc. It canget high accuracy measurement of size. Finally, comparing with the data measured bythe micrometer, and the experimental results show this system has the precision, speedand stability.The theoretical analysis and experiments prove that the light intensity interpolationalgorithm proposed in this paper and the high precision size measurement system hashigh detection precision. At the same time it is real-time and has good stability. Theresearch result has theoretical significance in this paper and practical value for theapplication of industrial on-line detection in vision measurement system.