Assembly Control Technology Of Array Ceramic Thermal Protection Structure For Digital Twins

The array of ceramic-based thermal protection structures is the primary protection structure for reusable carriers and the quality of its assembly has a critical impact on the performance and safety of the carrier.The ceramic-based thermal protection structure is characterised by the array arrangement on the carrier and the gluing to the body,which is affected by the accumulation of errors due to the number of components and the shape of the body surface,making it difficult to fully satisfy the assembly requirements by traditional assembly and positioning methods.Therefore,this thesis proposes a digital twinoriented assembly control technology for ceramic-based thermal protection structures,from the construction of a digital twin model in virtual space,the optimisation of the assembly position to the actual assembly control in physical space.The main research elements of the thesis are as follows:(1)(1)Propose a general scheme for digital twin-oriented assembly control.The digital twin technology assembly application is analysed and the digital twin assembly control application architecture is proposed;the digital twin assembly control system method for arrayed thermal protection structure components is designed for the assembly characteristics of arrayed thermal protection structure,the main methods of virtual space,physical space and the interaction between the two are studied and elaborated,and the specific assembly control process is proposed.(2)Constructed a virtual space assembly control model based on measured data of arrayed thermal protection structure components.Investigated the mapping relationship between the virtual and physical representations of the arrayed thermal protection structure,and built a digital twin using the measured point cloud data.Based on the distribution characteristics of the point cloud data,developed a model for solving assembly process parameters and optimized assembly poses.The FBI algorithm was employed to optimize the assembly poses of the components.The accuracy of the process parameter solving model was validated using a gap step difference standard gauge,with the results showing an error within ±0.03 mm when compared to measurements from external measuring tools.Furthermore,an experimental setup was designed to verify the correctness of the assembly optimization model.(3)Designed a physical space assembly control scheme for the arrayed thermal protection structure.Established an assembly control system and explained the positioning principles of each system,as well as the coordinate system approach.Described the assembly control process,control parameters,and their solution methods.To facilitate assembly control,designed assembly feature points and local coordinate systems that represent the actual poses of the components,enabling precise positioning.Conducted research on iterative methods for control parameters in the virtual and physical spaces,enabling feedback iteration of data during the assembly process.Additionally,designed experiments to validate the feasibility of the proposed scheme.(4)Designed various modules for digital twin-based assembly control and a largescale simulated model of the arrayed thermal protection structure.From the perspective of system integration testing,conducted assembly experiments using the proposed theories and methods in this thesis.Compared the results with traditional assembly methods to validate their correctness and efficiency.