Research On The Coaxiality Detection System Of Hole System For Large Structural Components

For the coaxiality measurement of large structural components,after analysis,it was found that the components have technical indicators such as large hole spacing,small aperture,and high accuracy requirements.By analyzing the relevant coaxiality detection systems at home and abroad when measuring large structural components,it was found that the existing measurement systems have limitations such as slow measurement speed and low accuracy.Therefore,this paper proposes a non-contact measurement method based on laser displacement sensors,We have developed a coaxiality detection system for large structural components.The paper mainly focuses on four aspects of work:(1)A method for evaluating the coaxiality of large structural components has been determined.There are four existing evaluation methods for coaxiality.By analyzing the applicability and impact of the four evaluation methods on the measurement of coaxiality of large structural components,it is believed that the common axis method can meet the measurement needs of large structural components and meet the definition of national standards.The key to implementing this method is the method of obtaining the reference axis and the actual measured axis by fitting the measurement points.This article uses the least squares method to fit the axis.(2)The effectiveness of the coaxiality measurement method proposed in this paper was verified through numerical simulation.Generate a simulation dataset through UG modeling,determine the cross-sectional positions of two holes according to algorithm requirements,and obtain the coordinate values of five sampling points with equal angles of each cross-section.After the fitting of the algorithm in this article and the comparison of measurements using UG tools,it can be seen that the calculation results remain consistent.Similarly,adding measurement noise to the dataset can also effectively detect coaxiality,indicating that the algorithm has good robustness.(3)Developed a coaxiality detection system for large structural component hole systems.According to the measurement principle,the mechanism design part includes a rotating motion mechanism and a translational motion mechanism,so that the laser displacement sensor installed on the measurement axis can collect the coordinate points on the selected cross-section of the left and right holes.In order to achieve the measurement process,the software and hardware design of the system was completed,including data collection through Lab VIEW,programming of the microcontroller to achieve communication between the upper and lower computers,and data processing of the coaxiality algorithm using MATLAB software.According to the design accuracy requirements,precision analysis and selection of laser displacement sensors,servo motors,stepper motors,and linear guides are conducted.Through comprehensive error calculation,it can be determined that the theoretical design error of the entire coaxiality measurement system is 0.11 mm,which meets the detection requirement of 1mm coaxiality for large structural components.(4)The effectiveness of the coaxiality algorithm and coaxiality detection device studied in this article has been verified through experiments.After calibration,the measurement system was used to measure the cylindricity of a single hole,and the detection result was 1.554 mm,which is slightly worse than the result of 1.507 mm measured by a three coordinate system.This reflects to some extent that the measurement system has good measurement accuracy.Then,experiments and numerical simulations were conducted to measure the coaxiality of two holes,and the results showed that the measurement system can effectively detect coaxiality and complete one coaxiality detection within 3 minutes.