Study On 3D Indoor Positioning Based On Fingerprinting And Sensors Of Smartphone

Connectors are basic electronic components that play an on-off role in circuit connection.Connector detection in modern industry is developing towards miniaturization,lightweight and precision.The production of connectors is a typical pipeline production,with a output rate of 2000 pieces per minute.At the same time,connectors enterprises have strict control over product quality.The coplanarity of connector pins is an important index to evaluate the quality of connectors.Traditional detection methods have low detection efficiency and accuracy,while most of the automatic detection equipment based on machine vision is expensive,and can not be popularized in small and medium-sized enterprises.In this paper,a three-dimensional scanning system for coplanarity detection of connectors is designed by using line lasers and COMS cameras.It has the characteristics of low cost,simple structure,non-contact and high accuracy.The following research contents are mainly completed:(1)Through the analysis of the dimension and detection requirements of the connector,a suitable line laser scanning platform is built to acquire the 3-D point cloud data of the connector by choosing the layout of direct laser triangulation.(2)Calibration of camera internal and external parameters and parameters of linear structured light system under halcon.Based on the principle of laser triangulation,a program is designed to reconstruct the three-dimensional surface contour of docking plug-in.The threedimensional contour coordinates of the docking plug-in are transformed into point cloud data in PCD format.(3)RanSAC(Sampling Consistency)segmentation,filtering,Euclidean Clustering,centroid calculation and so on are processed to locate the top coordinates of the pins accurately.(4)Fitting the top coordinates of the pins of the connector,and evaluating the coplanarity of the pins of the connector by comparing the maximum distance between the pin coordinates and the fitting plane and the set distance threshold.Experiments show that the detection method designed in this paper can be used to detect the coplanarity of pins of various types of connectors.The detection accuracy of a small pin-seat connector is 99.6%,and the repeatability accuracy can reach 0.022 mm.