多自由度数字射线成像检测系统设计

Design of multi-degree-of-freedom digital radiographic testing system

针对目前运载火箭箱底、筒段、圆环零件的焊缝采用传统胶片照相进行检测,存在自动化程度低、过程繁琐、数字化程度低、且底片无法进行长期保存,无法满足当前多型号火箭并举下的快节奏研制需求.运用X射线与成像板相结合的无损检测方法,采用双七轴机器人和同步升降转台作为运动执行机构,采用ADS多线程通信与Ethercat总线方式实现倍福控制器、成像检测软件、射线机、机器人和同步升降转台的实时通信,研发了一种基于机器人的多自由度数字射线成像检测系统,通过运动执行机构的路径规划与无损检测焊缝成像实现产品环缝、纵缝、变曲率焊缝的检测自动化,与传统胶片照相相比,检测效率提升5倍,检测精度提高42%,满足了目前对多型号火箭贮箱的检测工作.

At present,the traditional film photography is used to detect the welding seam of the bottom,barrel and ring parts of the launch vehicle,which has the disadvantages of low automation,complicated process and low digitization,and the negative film can't be preserved for a long time,so it can't meet the fast-paced development requirements of the current multi-type rockets.A robot-based multi-degree-of-freedom digital radiographic inspection system was developed by using the nondestructive inspection method combining X-ray and imaging board,using double seven-axis robot and synchronous lifting turntable as motion actuators,and using ADS multi-thread communication and Ethercat bus to realize the real-time communication among the controller,imaging inspection software,X-ray machine,robot and synchronous lifting turntable.Through the path planning of the motion actuator and the nondestructive inspection of weld seam imaging,the inspection automation of circumferential seam,longitudinal seam and variable curvature weld seam of products is realized.Compared with the traditional film photography,the inspection efficiency is increased by 5 times and the inspection accuracy is increased by 42%,which meets the current inspection work of multi-model rocket tanks.Highlights:(1)A multi-degree-of-freedom digital X-ray imaging inspection system with dual robots is developed based on the weld inspection of multi-model rocket tanks.(2)The automatic inspection technology for the welding seam of rocket tank is designed.