A Weighting Radius Prediction Iteration Optimization Algorithm Used in Photogrammetry for Rotary Body Structure of Port Hoisting Machinery

Abstract

As a non-contact measurement technology with high data acquisition efficiency, photogrammetry is an ideal choice for collecting the data needed in the safety evaluation of port hoisting machinery. However, the radius fitting result accuracy cannot meet the requirements of safety assessment due to the limitation of the port crane itself and the working environment characteristics, when the existing photogrammetry method is used to measure the rotary body structure represented by the portal crane slewing mechanism. In order to solve this problem, an iterative optimization algorithm for weighted radius prediction for the photogrammetry of the slewing mechanism of port hoisting machinery is proposed in this paper. First, the algorithm uses the generalized multi-line rendezvous model to transform the radius fitting problem into the multi-line intersection point prediction problem, which lays a theoretical basis for the subsequent algorithm implementation. Second, by introducing a weighting algorithm based on the camera optical distortion model, the algorithm optimizes the accuracy of radius fitting results. In addition, through the quantitative evaluation method of fitting accuracy based on weighted algorithm, the algorithm also establishes a set of iterative rules to balance the accuracy of measurement results and the execution efficiency of the algorithm. Finally, this paper designs theoretical verification tests and simulation engineering tests based on the characteristics of the algorithm and the engineering practice of port hoisting machinery photogrammetry. The experimental results demonstrate that the algorithm described in this paper can significantly improve the accuracy of radius fitting results when the data quantity is small and the data quality is poor compared with the traditional algorithm.

Prediction and Optimization Algorithm for Intersection Point of Spatial Multi-Lines Based on Photogrammetry

“…The application of close-range photogrammetry in port machinery and other large construction machinery is also increasing. Lu Enshun from Wuhan University of Technology [37] developed a photogrammetry-based radius measurement algorithm for the structural characteristics of port machinery, he used the approximate distortion model of the camera to determine the weight of each midperpendicular, and compared the equal-weight fitting algorithm with the weighted fitting algorithm. Wang Qi [38] developed a focal length calibration algorithm based on photogrammetry for port cranes.…”

“…In order to comprehensively consider the distortion of image points [52,53], the error of point selection, and the different shooting conditions of each image, the algorithm introduces information entropy [54,55]. Then the spatial lines involved in the calculation of fitting points are weighted [37] to further improve the fitting accuracy.…”