# Digital Simulation and Analysis of Assembly-Deviation Prediction Based on Measurement Data
## 4 Discussion  
The assembly-deviation-simulation model, based on three high points constituting a plane, considers the highest point of the point cloud constitution as the mounting surface, which is a closer approximation to the actual state of the axial length superposition than the least squares fitting model. As such, the prediction for the collision is more consistent with the actual state. However, this method employs fewer points, which results in a steeper slope of the fitted surface than that of the least squares fitted surface. Consequently, there may be a greater slope in the radial direction of the assembly model, leading to significant deviations in the predicted radial runout values. When comparing the results with previous studies, it is important to note that the old studies provided practical examples and methods for analyzing and optimizing assembly utilizing deviation-analysis software [15; 16; 17]. Based on these examples and methods, a simulation model was successfully developed to predict assembly deviations using \begin{table}
\begin{tabular}{c c c c} \hline  & **A** & **B** & **C** \\ \hline Actual assembly & 1.2 mm & 0.183 mm & 100.0\% \\ Assembly Based on Least & 1.2 mm & 0.194 mm & 67.3\% \\ Squares Fitting Surface & & & \\ Assembly Based on Three High & & & \\ Points Forming a Plane & 1.2 mm & 0.202 mm & 99.5\% \\ \hline \end{tabular}  
[FOOTNOTE:]Footnote : footnotetext: A—Radial total clearance between the turbine blade tip and the outermost clearance of the turbine guide. B—Radial runout of rotor blade tip. C—Collision probability of 0.47 mm pushed back.[ENDFOOTNOTE]  
\end{table} 
Table 2: Comparison of simulation results of different assembly methods. Figure 10: Extraction of representative three points on the mounting surface of motor housing. design tolerances and measured data, focusing on a micro gas turbine as the research object. However, the previous studies only focused on the analysis and optimization of assembly deviations in design models, without further integrating the measured data of the components with the design models. In this study, highly accurate measurements of the geometric shape, form and three-dimensional contour of key components were performed to determine the critical feature parameters that affect assembly results. An assembly-deviation-prediction and -analysis model was established based on the actual measurement data, and a comparison was made between the results of the assembly-deviation analysis and the assembly results to identify the best digital assembly-deviation-prediction model based on actual measurements. This research analyzes and predicts the assembly of actual components through a digital assembly based on measured data, providing a basis and guidance for the actual assembly process. Although there are important discoveries revealed by these studies, there are also limitations. Further research can be conducted in the future on the following:  
1. One avenue for further research involves exploring the digital assembly of thin-walled and easily deformable parts. While this study analyzed the micro gas turbine parts as rigid components, it is acknowledged that certain components within the turbine are thin-walled and deformable. As such, the established digital assembly model has inherent limitations. Expanding research efforts to encompass the assembly of these thin-walled and deformable parts could yield a more accurate simulation and analysis model of assembly deviation. Furthermore, such research has the potential to offer valuable insights for the assembly of advanced power plants, including aviation and combustion engines. 2. Additional investigation into the mathematical model of assembly is required. Several scholars have proposed novel mathematical models for digital assembly and deviation analysis. Further research on mathematical models can facilitate the integration of theory and practice, leading to the establishment of a digital assembly-deviation-analysis model that more accurately reflects the real-world scenario. 3.