Reaserch On Automatic Plugging Technology Of Aircraft Thermal Protection

The screw hole at the joint of aircraft cabin shall be coated with glue on the inner wall and bottom of the round hole before the product is sealed,and then sealed with a plug to ensure its thermal sealing.In this paper,aiming at the problems of low sealing efficiency,serious waste of glue and poor consistency of glue coating existing in manual operation mode,the automatic sealing technology of round holes on the outer surface of aircraft was studied.Based on the analysis of the existing problems in the manual sealing process of the circular hole,a scheme of automatic glue sealing of the circular hole was proposed: the AGV walking system realized cross-region operation,took the manipulator with lifting function as the actuator,and the vision system provided the coordinate information of the circular hole to guide the manipulator to complete the glue sealing of the circular hole,and verified the working space of the system through simulation calculation.Analyze the coating accuracy of the system,design the visual system,and determine the technical parameters of the camera.Improved Canny operator edge detection algorithm for circular hole identification and positioning: filter invalid point cloud and reduce noise through image preprocessing;The Qstu method was used to segment the image,and the image closing operation was used to make up the edge defect and get the round hole edge.Then the position and pose information of the circular hole was output by the fitting calculation method to guide the operation of the manipulator,and the repeatability accuracy of the circular hole fitting calculation method was verified.By analyzing the properties of the adhesive and the way of coating,the technological parameters that hinder the stable coating of the system are obtained: the inner diameter of the needle of the rubber hose,the pressure of the automatic coating machine and the time of the automatic coating machine.The relationship curves between different process parameters and the amount of glue produced were obtained by using the amount of glue produced as the characteristic quantity,and the range of parameter selection was determined.Orthogonal test was designed based on orthogonal table,and the optimal process parameters were obtained by using the sealing effect of round hole as the criterion.Based on the round-hole automatic plugging scheme,the hardware and software of the round-hole automatic plugging system were designed,the three-dimensional model of the system was drawn,and the whole machine was prepared.Using Python programming language and third-party visual algorithm library Open CV,the image processing program was compiled on VS Code platform,and the human-computer interaction interface was written with C++ language based on QT platform.The experimental results show that the automatic plugging system can accurately identify and locate the circular hole,and the sealing effect of the circular hole meets the thermal sealing requirements of aircraft.Through the above research work,the automatic gluing and plugging operation of the round hole on the outer surface of the aircraft can be realized.At the same time,the research also provides certain ideas,methods and solutions for the automatic operation of other parts of the aircraft.