Research On Non-contact High-precision Inner Diameter Measurement Technology

In modern manufacturing and processing industries,pipelines are widely used in aerospace,national economy,weapons and equipment and many other fields.The barrel is usually the core part of the whole set of equipment,and its inner diameter and other parameters have an important impact on whether the whole set of equipment can achieve the expected performance index.At present,there are some problems in the inner diameter detection equipment of barrel in China,such as low precision,cumbersome operation and low efficiency.Therefore,it is of great significance to study the inner diameter measurement technology of barrel.Based on the comparison of various existing barrel measurement methods,an automatic intelligent measurement system using dual laser displacement sensors to collect the inner diameter parameters of barrel is designed,so as to realize the long-distance and nondestructive collection of the inner diameter parameters of pipe.At the same time,according to the structure of the measuring equipment,a measuring algorithm for calculating the inner diameter of the barrel is designed.The measuring system designed in this paper has simple structure and convenient calibration of the measuring head.Wi Fi wireless communication technology is used in the measurement system to realize the control and data transmission of the measurement system,avoid the winding and dragging of the transmission line in the pipeline due to the long pipeline,and improve the flexibility of the measurement system in practical engineering application.The inner diameter measurement algorithm designed according to the structure of the measuring equipment reduces the error amount when the measuring equipment collects data in the detection,and further improves the measurement accuracy.The research contents of this paper are as follows:1.the existing barrel inner diameter measurement system and its matching measurement algorithm are analyzed in detail,and their remarkable characteristics,advantages and disadvantages are summarized.The single sensor and dual sensor measurement of barrel inner diameter are simulated respectively.According to the simulation results,a measurement system based on dual laser displacement sensors is designed.In addition,a measurement algorithm matching the system structure is designed.After the mathematical model is established b y using the geometric relationship,the collected measurement data are used to calculate the inner diameter of the barrel,draw the standard circle of the barrel and the actual contour of the inner wall of the barrel,and compare the two images to determine whether the barrel meets the design standard.2.Based on STM32,power supply,serial port,serial port to Wi Fi,this paper designs the structure of circuit hardware,which is used to control the operation of measurement system and wireless transmission of measurement data.The human-computer interaction interface is designed by QT software,which realizes the control of the whole system and the transmission,storage and processing of data.3.According to the starting point of the sensor structure,the calibration method of the sensor is designed.The main factors affecting the measured value in the measurement system are analyzed.4.Use the completed measurement system to carry out relevant experiments of barrel inner diameter measurement to verify whether the inner diameter value measured by the measurement system meets the accuracy requirements of the design and whether the inner contour curve of barrel can be displayed normally.