Plant Design And Precision Control Of Large Propeller Blade's Laser Measurement

The accurate measurement of the propeller is the basis and premise for the subsequent processing. The heavy weight and big volume of the marine propeller makes it difficult to fix, the traditional contact measurement method is time-consuming and the precision is easy affected by man-made factors. In order to achieve the automation and intellectualization of detection for propeller blade, this subject is based on the Jiang Su province's support program “The intelligent detection and quality evaluation equipment for the large propeller blade”. We developed laser measurement system for the large propeller blade, which integrates the non-contact laser probe and the software modules on the double cross arm measurement machine, this measurement system can realize the accurate detection of the propeller and the quality evaluation of the finished products. The main content of this paper includes the following several aspects:First, this paper introduces the various detection methods for large propeller, and on the basis of analyzing the advantages and disadvantages of the traditional manual measurement methods and the contact probe measurement methods, it suggests the non-contact laser detection method, designs a set of special equipment, improves the measuring process and solves the problem of blade turn in the process of measuring.Secondly, this paper analyzes the measurement conditions and goes into the issue of laser measurement's accuracy. Setting up an experiment platform for the laser measurement, it analyzes the factors that affect the precision of measurement, such as roughness, surface slope and laser beam's direction. According to the spatial light intensity distribution, an error compensation model was put forward for the surface slope. This paper also proposes a calibration method to calibrate the laser beam's direction.Thirdly, the paper introduces the date collection and storage, analyzes the methods of date preprocess, such as how to distinguish and eliminate the defect date, how to simplify the date and how to split the topological structure.Then, it introduces the realization of the laser measuring system of large propeller in detail, the effectiveness of the compensation method, the calibration method of laser beam's direction and the date preprocessing method has been verified.Finally, it makes a conclusion on the main research, and speculates on the following study.