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• Feature extraction method can extract required data from the raw scanning data. • Derive the optimal position of leapfrog balls and improve calibration accuracy. • Use SVM to determine the parameters of edge-determination method. • Complex components can be measured and analyzed. • The proposed method can significantly reduce time consumption. In the manufacturing industry of aviation equipment (e.g., ballistic missile, rocket, unmanned aerial vehicle (UAV), and airplane), the traditional assembly quality inspection methods mainly rely on manual operation of single- or multi-stations laser trackers, but they are powerless to measure and evaluate complex components on the aviation equipment. This paper introduces a method for automatically detecting and evaluating assembly accuracy: first, the global accurate calibration is performed automatically by deriving the optimized positioning of leapfrog balls; after selecting the aviation equipment type to determine the measurement tasks, each side of the aviation equipment is equipped with a robot and an accompanying FARO scanning arms that can move together on the U-shaped guide rail to the measurement station where the measurement task is to be performed; at each measurement station, the robot drives the movement of the FARO scanning arm through a linkage mechanism to perform scanning; after the whole measurement processes are completed, data from multiple measurement stations is integrated into the same coordinate system for calculation and assembly quality analysis. The algorithm module consists of path planning function for scanning various parts, feature extraction function for various geometric elements, and assembly quality evaluation function. Compared with laser tracker method, the proposed method can effectively and accurately measure and analyze basic measurement tasks: the maximum differences of length, concentricity, and perpendicularity are all less than 0.3%; while the time consumption can be significantly reduced to less than 5% of that of the laser tracker method. Moreover, the proposed method can also achieve the automatic measurement and analysis of complex positioning components that cannot be achieved by laser trackers, e.g., center of positioning hole, position deviation of the bump, and azimuth angle between the positioning surfaces. [ABSTRACT FROM AUTHOR]

• We present a Six-Point positioning algorithms which can automatically update tool coordinate system. • We choose two kinds of measurement paths for testing the wall thickness values of the blades. • Our method can automatically determine suitable adjustment parameters for distorted wave shapes. • Our method demonstrates excellent precision, accuracy, and stable. It can greatly improve the measurement efficiency. Compared with inner solid structures, the inner hollow structures of turbine blades show excellent mechanical properties and better physical properties, e.g., excellent heat dissipation and diversion effects, and light weight. Its complex inner structures cannot be detected accurately by traditional testing methods. Among all non-destructive testing (NDT) methods, ultrasonic testing method has certain advantages in measurement accuracy and efficiency for measuring wall thickness values. The accuracy of measurement results is provided by four criteria: precision, accuracy, stability, and efficiency. However, ultrasonic testing method still faces new challenges that are barely explored, e.g., inner structures have unique characteristics of complex geometrical features, the measurement process need to meet high-precision positioning and quickly detecting requirements. In this paper, in order to improve the detection accuracy and efficiency, an industrial robot is used to substitute the existing detection methods: once a new blade is clamped by terminal mechanism, a new calibration method adopted the six-point positioning scheme was provided to solve the problem of rapid and accurate updating tool coordinate system. The support vector machine (SVM) system was used to output regression results of the adjustment parameters based on the geometric features of distorted wave shapes. Two kinds of measurement paths were used to measure the wall thickness values for accurate measurement. The experimental results show the superiority and effectiveness of our method in terms of measuring stability, accuracy and testing efficiency. [ABSTRACT FROM AUTHOR]