Laser ablation technology, with its high energy density, excellent focusing capability, and non-contact nature, has become an ideal choice for processing superhard materials. To develop a CNC laser machine tool for processing superhard cutting tool materials, a kinematic model of the machine tool was established using the D –H method, determining the range of motion for each axis and defining the workspace based on the machining coordinate system. Subsequently, post processors were developed using various methods such as MATLAB, Python and UG to convert the machining instructions into executable instructions for the machine tool control system. Finally, a virtual machine tool was created in VERICUT for motion simulation to validate the accuracy and effectiveness of the kinematic model. The simulation results confirmed that there were no collisions or programming errors during the machine tool motion, indicating the accuracy and reliability of the constructed kinematic model. The study also revealed that incorporating a dual rotary table increased the workspace of the machine tool by 1.9 times when the laser focal length was set at 130 mm, thus meeting the requirements for more complex machining tasks.

Aero-engine design and simulation technologies thrive in metasynthesis and integration. Meanwhile, with the improvement of system engineering methodology, the digital revolution in aero-engine field is in the ascendant. The concept, current situation, demand and key technical issues of aero-engine digitization are reviewed in the hope of providing reference and support for chinese aero-engine digital transformation. Facing the complex essence of aero-engine, the concept and connotation of model-based system engineering, digital twin and digital thread are analyzed, and the definition of digital engine is further developed. The use cases and development status of digital engine at home and abroad are summarized and the work needing to be done including model and algorithm library, general platform, data connectivity and processing, coupled and integrated simulation technologies, data analysis and decision making is discussed, according to the technical trends and challenges. Aiming at the key technical problems of digital transformation, the relevant research content and direction of the disciplinary simulation integration method, the communication method of system model and discipline model, and the digital twin modeling method are discussed. The idea and specific research content of digital engine can provide the foundation for subsequent planning and construction of aero-engine digital twin systems.

Aiming at the difficult configuration and planning scheduling of the machining production line of spacecraft structural parts, as well as the high overall occupancy rate, low utilization rate and limited capacity improvement  of the production line, a digital twin based on the reconstruction of the production line of spacecraft structure products and adaptive scheduling method is proposed. Based on the operation mechanism of “visual monitoring based on digital twin + rapid reconstruction of production line + adaptive scheduling of real-time perception”, the three key implementation technologies of the above method, namely 3D visual monitoring based on digital twin, rapid reconstruction of production line driven by task and workshop operation status data and adaptive scheduling based on reconstructed production line and real-time perception data, are elaborated. Design and develop a virtual dynamic reconstruction system for intelligent workshops based on digital twins to verify the effectiveness of the method.

Based on the concept and principle of digital twin, as well as the current promising manufacturing technologies: Automatic fiber placement based liquid composite molding, by sorting and analyzing the key links of the AFP–LCM, this article elaborates on several key issues that urgently need to be solved in the establishment of digital twinning for the manufacturing of composite material components in civil aircraft. It also proposes a systematic architecture for the manufacturing technology of composite material structures in civil aircraft based on digital twinning. This paper discusses the problems faced by the implementation of this technology from both technical and policy perspectives, and it provides strategies for the practice in-depth of digital twinning technology in the field of composite material manufacturing in civil aircraft.

Fiber winding composites are widely used in high-tech fields such as aerospace due to their excellent specific strength and good designability. However, current domestic research on fiber winding molding technology is mostly focused on winding theory and CAD/CAM software, and the development of online virtual simulation technology for fiber winding is still in its early stages. This study proposed a new calculation method to display the fiber trajectory in the fiber winding process in real-time by establishing a virtual mapping of the physical machine tool through OpenGL. The link between the virtual machine tool and the physical machine tool was established via the Modbus TCP protocol to enable real-time monitoring of key parameters in the fiber winding process. In addition, bi-directional data exchange between the virtual machine tool and the physical machine tool, as well as control of some operation commands, was achieved through the NC-API interface provided by the Huazhong 9 CNC system. The winding experiments show that the fiber winding virtual simulation system developed based on digital twin technology can complete the real-time motion simulation of the fiber winding process, the monitoring of key parameters of the winding process and the direct control of the winding process. This study has completed the functional requirements of remote monitoring and remote control of the fiber winding process.

The residual stress of parts is one of the critical factors affecting the machining quality during the cutting process. Visualizing the evolution process of residual stress field in virtual environment can effectively monitor its evolution law, which helps to improve the machining quality of parts. In order to achieve real-time mapping of stress field in virtual environment, a real-time mapping method for stress field in clamping was developed based on digital twin technology. Firstly, the overall architecture of the digital twin in the cutting process was elucidated. Secondly, a mapping scheme for the residual stress field during the machining process in a virtual environment was proposed. Specifically, based on the finite element simulation method, an approximate model for the simulation of residual stress during clamping was established using RBF neural networks; The data-driven method was used to achieve the mapping of approximate model simulation results in a virtual environment. Finally, taking the distribution of residual stress field during workpiece clamping as an example for verification, the maximum deviation between the real-time simulation results of the approximate model and the finite element simulation results is 7.7%, which verifies the feasibility and effectiveness of the real-time mapping method for stress field. In general, this method provided the technical support for digital twin in the cutting process.

Aircraft bearing component is the key bearing component of large passenger aircraft and fighter aircraft, which is prone to dimensional deformation during the forming process. However, the current caliper, plug gauge testing method has some problems, such as low efficiency and poor consistency of results. To this end, this paper intends to solve above problems by three-dimensional measurement technology. This paper proposes a crude registration method based on standard spherical characteristics and a fine registration method based on the shaft hole key characteristics. Meanwhile, studies the size/shade error systematic automatic calculation method of the aircraft support member, and conducts digital detection experiment of a model aircraft holder member based on autonomous software modules. The results show that the proposed method has significantly improved the detection efficiency and stability compared with the manual detection method.

In order to accurately and efficiently forecast the cutting force of complex surface multi-axis machining, a cutting force model based on Gaussian process regression (GPR) algorithm is developed in this paper. Feature parameters of tool–workpiece engagement, such as tool-axis inclination angles and cutting width, which serve as input characteristic parameters of GPR model for cutting force prediction in complex surface machining, are extracted based on cutter location file (CLS). The training set of the GPR model are obtained using the mechanical force model where the tool–workpiece engagement is calculated by Boolean operations. Cutting force simulation software for complex surface machining is developed and the efficiency of the proposed GPR model is verified by comparing with the traditional force prediction model which adopts the Boolean operations to calculate the tool–workpiece engagement. The error of cutting force prediction is less than 10% and the evaluation coefficient of prediction results is maintained above 0.98. An impeller runner machining experiment was designed to verify the accuracy of the GPR model proposed in this paper for predicting cutting force in machining complex curved surface. In force prediction based on the same CLS file for an impeller passage processing, the method using Boolean operation takes 161 s, while the time elapsed of the proposed model is only 1.63 s. The results indicate that the proposed model is efficient and accurate for cutting force prediction in complex surface machining.

Sapphire wafers are affected by many factors during the lapping machining, In order to improve the surface quality of the sapphire lapping machining, by consideration of the volume distribution and flow uniformity of the lapping liquid, the surface texture of the lapping plate is designed. The finite element method is used to simulate the flow field of the designed lapping plate. At the same time, the stress distribution on the surface of lapping plate was simulated by finite element method. In order to verify the processing performance of the lapping plate, the designed lapping plate is compared with the ordinary lapping plate in the lapping experiment. The results show that the design of Archimedes spiral groove plus radial groove with groove width of 2 mm and groove depth of 1 mm is adopted, the surface roughness of the sapphire wafer reaches 0.210 μm, the surface of the wafer has no damage such as crushing and pits, the effect is significantly better than the ordinary lapping plate, therefore the lapping plate designed in this paper has better machining performance.

The construction process of workshop digital twin models is complex, with diverse functional modules and data types. Currently, there is a lack of systematic and structured modeling and analysis methods guided by toplevel design. Traditional modeling methods with a single design structure are prone to content duplication or omission when constructing workshop digital twin models, making it difficult to achieve the systematic modeling requirements of workshop digital twin models. Based on the complexity of the workshop digital twin model and the diversity of IDEF method class expressions, a structured modeling and analysis method of the workshop digital twin model from four dimensions of functional modeling, information modeling, process modeling and ontology modeling is proposed. IDEF0 is used to describe the function of the digital twin model on the shop floor through functional decomposition and classification of the relationship between functions; IDEF1x is used to describe important information during the operation of the shop floor digital twin and define the interrelationships between data entities; IDEF3 is used to accurately describe the process changes and state transfers in the workshop with the data flow process during the operation of the workshop digital twin as the core; On the basis of information modeling and process modeling, IDEF5 is used to obtain concepts, terms and relationships in the field of workshop digital twins, and to collect facts and acquire knowledge through ontology modeling of the operation process of workshop digital twins. This method effectively avoids the problem that a single expression may only describe a certain feature in a complex system and ignore other important information, laying a foundation for improving the semantic consistency, reusability, structure, and automation of the workshop digital twin modeling process.

Aiming at the errors caused by hysteresis nonlinear effect in the operation of piezoelectric ceramic actuators, a hysteresis compensation control method is proposed. Firstly, for the hysteresis nonlinearity, the corresponding hysteresis model is built based on the PI model, and the inverse model is used to adjust the input voltage of the piezoelectric actuator. Secondly, aiming at the shortcomings of PI model, PID closed-loop control is combined to further compensate the hysteresis error. Finally, the piezoelectric hysteresis compensation control system is built based on LabVIEW FPGA module, and the elliptic vibration trajectory control experiment is studied. The experimental results show that the maximum relative error of the displacement of the piezoelectric actuator under the composite control is less than 3%.

GH4169 superalloy is widely used in aero-engine hot components, and improving the fatigue resistance of GH4169 superalloy aero-engine blades is of great significance for the long-term stable service of aero-engines. Abrasive belt grinding is a finishing process of aero-engine blades, and the grinding parameters are closely related to the surface state and fatigue resistance after grinding. To reveal the effect of abrasive belt grinding process parameters on the fatigue resistance of the ground surface, this study carried out abrasive belt grinding on GH4169 superalloy fatigue samples with different process parameters and explored the influence of process parameters on surface integrity and fatigue life law. The results show that the line speed, feed speed, and downforce have significant effects on the surface roughness and residual stress of the GH4169 superalloy workpiece after grinding. When v=11 m/s, f =1000 mm/min, F=3 N, the fatigue resistance is the best. When the linear velocity is greater than 15 m/s and the downward pressure is greater than 6 N, the surface of GH4169 superalloy decreases, the depth of scratches increases, and the burning phenomenon is serious.