There exists a class of components in aerospace equipment products whose external surfaces are freetolerance dimensions but whose local or internal parts have accurate assembly requirements. The lack of suitable external surfaces to be used as accurate positioning datums has led to challenges in automated assembly and manufacturing of these parts. As a result, these parts have long been assembled using inefficient manual assembly methods. To solve this problem, this paper takes the automatic interference pressing requirement of a pin in a rudder body as an example to carry out the research on the automatic assembly positioning method. Based on the analysis of the traditional one-side two-pin positioning error and the finite element analysis of the influence of positioning eccentricity on the press fitting quality, a new automatic assembly technology is proposed, which takes the assembled feature itself as the benchmark for accurate positioning. The test results show that this method can realize the precise positioning of the pin quickly. The research work provides technical support for the successful completion of a high quality and efficient automatic assembly line for the pin of a certain rudder parts.

With the gradual development of the manufacturing industry towards intelligence and flexibility, the collaborative work of robots and machine tools can make the entire production process more efficient and flexible. However, traditional control systems and cloud computing services are unable to meet the demands of their data interaction. This paper proposes an open edge platform service architecture for robot – machine tool manufacturing units. The proposed solution is based on real-time Linux, with ROS and LinuxCNC open-source platforms as the core, and employs EtherCAT master station communication for the robot–machine tool collaborative control system. Fast DDS is deployed in the controller and server to achieve network access for different data, and container technology is utilized to build an edge microservice environment, enabling efficient data interaction and transmission. Finally, an experimental platform was set up, and system performance tests were conducted. The experiments verified the feasibility of the proposed solution.

Due to the characteristics of nacelle acoustic liners, such as variable curvature, numerous holes, and tiny hole diameter and spacing, traditional drilling techniques are difficult to meet the needs of acoustic liner drilling. To improve the drilling efficiency and quality of the nacelle acoustic liner of a large aircraft’s aero-engine, a robotic drilling system with multi-spindle capabilities was developed. A multi-spindle drilling end-effector capable of machining acoustic array holes is designed to address the needs of drilling nacelle acoustic liner components. The end-effector can drill multiple small holes with a single positioning. Considering the complex curved shape of the acoustic liner and the robot’s reachability, a rotatable fixture table was designed to adjust the machining pose of the acoustic liner. An evaluation index for robot machining state was constructed by integrating multiple factors such as singularity, joint limits, and robot stiffness. A zoning scheme of the nacelle acoustic liner for machining was studied based on the layout characteristics regarding the robot and workpiece of the multi-spindle drilling system. The processing parameters for holes of composite acoustic liner are determined by drilling process tests. The results show that the drilling efficiency of multi-spindle drilling system is 4.37 times that of single-spindle systems. The zoning for machining ensures optimal processing conditions for each drilling point. Using a spindle speed of 30000 r/min and a feed rate of 700 mm/min, defects often occurring in drilling, such as burrs and splits, are effectively avoided, reducing the delamination factor to 1.267, which can meet the manufacturing
requirements of aero-engine nacelle acoustic liners and also has significance as a reference for high-density array hole processing in other fields.

To meet the growing demand for composite components in the aerospace manufacturing industry, an integrated robotic automated fiber placement system and associated CAM software have been designed for the problem of automated molding of composite materials. The integrated design of the laying head and the yarn frame effectively reduces the total volume of the machine and shortens the yarn transfer path. The core component of the laying head has been designed with shearing, re-feeding, clamping, heating and pressure mechanisms, enabling it to realize the mentioned functions. An autonomous and controllable automated fiber placement CAM software is developed based on C++ language, Qt framework, OpenCASCADE and OpenGL. The functions of display interaction, trajectory planning, layup analysis and motion simulation are integrated together, which greatly improves the usableness and operational efficiency of the software. Finally, it is verified by curved surface automated fiber placement experiments. The results show that the designed robotic automated fiber placement system and the CAM software can ensure the accuracy, stability and reliability in the laying process.

Guided by the requirements for highly efficient and high-quality processing of large-scale complex components in fields such as aerospace, marine navigation, and rail transit, this paper explores the key technologies of the multi-mobile robot collaborative parallel manufacturing system for large components, which is based on the group robot clustered parallel manufacturing system. Centering on the processing technology requirements of typical large-scale components, and based on the design and development of various and multi-form mobile robots, including mobile measuring robots, mobile machining robots, and mobile assembly robots, this paper puts forward a collaborative parallel manufacturing scheme based on multi-mobile robots, a robot body design scheme for robotic machining of large components, a multi-modal collaborative robot sensing and measurement scheme, as well as control schemes for the multirobot  collaborative machining robot body controller and the group machining robot system. It elaborates on the control strategies and schemes for multi-group robots in mobile machining. Regarding key technologies such as the collaborative parallel machining methods for groups of machining robots, large component measurement, and group robot collaborative control, this paper not only explores ways to improve and optimize the performance of domestic industrial robots from the aspects of robot body research & development and controllers but also attempts to broaden the working ideas for subsequent large component processing in aerospace and other fields.

In the novel manufacturing mode of in-situ processing for large components by multi-mobile robots, reasonable arrangement of processing sequences and stations for each robot based on processing feature distribution and robot processing accessibility is crucial to ensure smooth processing implementation. This paper focuses on the surface processing requirements of multiple brackets on large aerospace cabin bodies. After explaining the principles of the multimobile robot parallel processing system, the paper emphasizes the problems of processing area partitioning and robot station planning. Firstly, the multi-robot parallel processing flow is outlined, methods for axial and radial partitioning of the cabin are proposed, and the cabin workspace rasterization is performed. Then, by utilizing the inverse solution of the robot, the feasible robot station set is extracted to accomplish the station planning for multiple mobile robots. Finally, a multi-robot system containing four types of robots is chosen, and simulation verification is conducted on an example cabin. Compared with the traditional method, the multi-robot parallel processing method proposed in this paper increases the production efficiency of large cabin brackets processing by 82%, and the effect is remarkable.

To achieve the automated grinding and polishing of the blade tip fillet in an aero-engine blade, a study on the micro-arc fillet grinding and polishing process based on elastic grinding tools was conducted, and a highly controllable method for machining the micro-arc fillet of the blade tip was proposed. An elastic grinding and polishing wheel with polyester fiber as the base material was employed. By leveraging the characteristic of elastic deformation of the grinding and polishing wheel during the machining process, the abrasive coated on the surface of the base material was used to grind and polish the blade tip apex angle into a micro-radius fillet. Based on the elastic contact theory and the Preston removal theory, the theoretical contact model and material removal model of the grinding and polishing wheel and the blade tip apex angle under the machining state were established. The Abaqus software was utilized to perform a simulation analysis of the stress in the contact region of the model and to simulate the removal distribution function. Theory proves that through the adaptive enveloping contact deformation between the elastic grinding and polishing wheel and the blade tip apex angle, a “micro-surface contact cutting” was formed between the machining region and the grinding and polishing wheel, enabling the machining of a micro-radius arc fillet. The fillet grinding and polishing experiment of the blade tip apex angle was carried out to verify the feasibility and controllability of achieving the micro-arc fillet machining. The results showed that the adaptive enveloping deformation of the elastic grinding and polishing wheel led to an arc-shaped stress distribution in the contact region of the blade tip, and the abrasive coated on the base material could effectively grind and polish to achieve the fillet machining. This machining method effectively realized the automated machining of the micro-arc fillet of the blade tip, with good consistency in dimensional accuracy and surface quality. The roughness Ra was stable between 0.20 μm and 0.28 μm, and the variation in the fillet radius was stable within a range of 16 μm.

Thin-walled aero-engine casings have complex flow channel structure. In order to complete the milling machining and obtain higher machining accuracy, both ends need to be positioned and clamped respectively. The clamping technology of the casings was studied based on the clamping requirements. The finite element method was used to perform harmonic response analysis, and the clamping mode and pressing position were selected according to the deformation of the casings. A special fixture was designed according to the simulation results, and the compound clamping method of center hole positioning, bottom edge and upper-lower auxiliary clamping was adopted to effectively limit the six degrees of freedom of the casings. The calculation results show that the positioning error of the machine tool-fixture-casings meets the accuracy requirements, and the actual machining results show that the casings flow channel after repeated clamping and processing meets the machining accuracy and surface roughness requirements.

In-Sn/rGO composites with different In doping contents were prepared by sol–gel method combined with high temperature heat treatment using nano-SnO₂ as precursor. The effects of In content on the micro-structure, phase composition, defect degree, dielectric constant, electrical conductivity and dielectric properties of the composites were investigated. The results show that the introduction of In has no significant effect on the micro-structure and the phase composition, only slightly reducing the degree of defects in the composite material. With the increase of In content， the dielectric constant and electrical conductivity of the composite increase first and then decrease. The dielectric properties of In-Sn/rGO composite are best when the In doping mass fraction is 1.0%, the reflection loss value is –51.16 dB, the corresponding absorption frequency is 8.72 GHz, and the effective absorption bandwidth is 3.60 GHz.

A normalized model is proposed for the characterization of pre-stress state in shot peen forming process, in which the pre-stress of plates undergoing bending shot-peening deformation state is characterized by a pre-stress parameter. Quantitative relations are established between the curvature of shot peened plates and shot peening parameters with the inclusion of the influence of pre-stress state. Pre-stressing shot peen forming experiments were designed and carried out to verify the validity of the normalized model. Results show that quantitative formulations can be established on a normalized pre-stress parameter interval [0,1] for the description of the bending deformation behavior of pre-stress shot peened plates. When certain shot peening parameters are given, the curvature of the shot peened plate in the pre-bending direction is linearly related to the pre-stress parameter, proportional to shot peening pressure, quasi-inversely proportional to peening speed, and inversely proportional to the 3/2 power of the plates of thickness, while all the proportionality coefficients are determined by the pre-stress parameter.

With the iterative progress of science and technology, the traditional manufacturing industry is gradually shifting to centering on industrial robots as the core to carry out intelligent manufacturing. Due to the characteristics of large thin-walled, diverse structures, and varying sizes of rocket storage tank parts, most of the current production methods are manual processing, which is relatively inefficient. In order to solve the above difficulties, taking the pre-welding treatment method of rocket fuel storage tank parts as the research object, a robot automatic grinding technology scheme from scanning, planning to execution is designed. The pose relationship between the point cloud in the machining area and the robot base coordinate system was obtained by means of hand – eye calibration and coordinate transformation. A point cloud splicing method was proposed to extract the edge surrounding box, and corner detection was carried out using the window algorithm based on the edge curvature. Finally, the robot automatic grinding experiment of pre-welding processing of parts was completed according to the machining trajectory planning results, ensuring the grinding quality and efficiency. It has obtained a good application effect.