Research On Technologies Of Pin's Detection For Avionics Electronic Connector Based On Machine Vision

Avionics electronic connector is widely used in instumentation and aerospace system,it is responsible for signal transmission and power transmission in the entire system,so the reliability and safety of avionics electronic connector is essential to the entire system.At present,the pin's detection mainly depends on artificial visual detection,this method has low accuracy,low efficiency and the test result does not have repeatability and traceability.So this paper proposed a method of pin's detection based on machine vision,designed the entire system which can achieve high accuracy and fast detection for pin.This paper studied the technology of avionics electronic connector pin's detection.According to the measurement's requirement and technical indicator,determined the measurement scheme,finished the design and selection of system's functional modules based on machine vision and made the software on computer.The pin's recognition algorithm is studied.Firstly,the image has to be segmented according to the size chatacter of avionics electronic connector,preserve the image's region of interest;then studied the image filtering algorithm according to image quality;finally studied the pin's recognition algorithm,determined to use the template matching method based on gray feature to recognize the pin,choose the CCOEFF to calculate the similarity between the template image and the original image,got the pin's coarse postion.The pin's location algorithm is studied.Fistly calibrated the system's pixel equivalent,determined to use the dividing scale calibration method based on the least squares mehod,finished the calibration experiment;then discussing the algorithm of getting the pin's pixel coordinate,made experiments on gray centroid localization algorithm and weighted centroid localization method respectively.Finally,discussed the pin coordinate transformation algorithm,and made relevant experiments.The satandard uncertainty symthesis of the system is discussed.Analyed the error sources of the system and calculated the standard uncertainty of the system by stastistical mathod and non-stastistical method,finally syanthesized the system's overall standard uncertainty.And the accuracy of the system is measured by measuring the pin of known distance.The avionics electronic connector's pin detection system can meet the demand of the pin's detection of circular connector's pin.This system's accuracy is better than 0.06 mm,it can meet the measurement requirement of industrial site..