Assembly accuracy prediction and optimization of aero-engine rotor under the separation condition of assembly and measurement

Abstract

The measurement and assembly of aeroengine rotor are separated from each other, the uncertainty of the test position leads to the test data cannot reflect the geometric characteristics of the rotor itself, which makes it difficult to accurately measure and predict the assembly accuracy. Combined with the fact that the 2 geometric characteristics of parts / components are not related to the measurement datum, an assembly accuracy test and prediction method is proposed to reduce the datum deviation and ensure the consistency of test data. Firstly, the small displacement torsor is used to describe the datum deviation, the inverse matrix transformation is applied to reduce the datum deviation, and the datum independent matrix is utilized to express the pose characteristics of the parts / components, which provides the data basis for the accurate prediction of assembly accuracy. Then, the pose transfer model based on the datum independent matrix is established, which is more comprehensive and clearer than the traditional accuracy prediction model. Furthermore, a direct optimization method is also established, which is more efficient than the traditional genetic algorithm. The assembly experiment of aeroengine rotor shows that the model and method proposed in this paper are beneficial to reduce the coaxiality of the front and rear fulcrum and they can better reflect the geometric characteristics of the rotor itself. The related research also has reference significance for other large-scale and high-precision mechanical product assembly.

A Method for Assembly Accuracy Detection and Intelligent Error Estimation Based on Computer Vision

“…Through the software, prediction and simulation of various assembly stages can be achieved, which can maximize the accuracy of each assembly stage [2]. Minghua Li, proposed an improved genetic algorithm, which can predict the assembly accuracy of aeroengine rotor, and effectively overcome the problem that the assembly benchmark and Geodetic datum are difficult to keep consistent during the assembly process [3]. Wei Wu established a calibration error accumulation model for the multi sensitive axis assembly process based on the characteristics of hole axis assembly, and derived the relationship between machining error and angular deviation [4].…”

A Decoupling Algorithm-Based Technology for Predicting and Regulating the Unbalance of Aircraft Rotor Assembly Considering Manufacturing Errors

“…The offset of each centroid relative to the rotation axis can be obtained using Equation (14). The total unbalance quantity of the assembly can then be computed using Equation (17). By adjusting the assembly phase using the original prediction model, you can optimize the unbalance quantity for the seven-stage rotor under these manufacturing errors.…”

“…This approach enables the incorporation of geometric errors in the virtual modeling of mechanical assemblies. Li et al [17] proposed a datum error elimination method that takes into account the independence of geometric characteristics from the measurement datum. This method enhances the accuracy of the rotor characteristic matrix and assembly model.…”

Prediction of Array Antenna Assembly Accuracy Based on Auto-Encoder and Boosting-OSKELM

“…In order to study the effect of assembly error on the antenna gain, Guo et al [6] proposed an accurate gain prediction model using an improved XGBoost algorithm and the transfer learning method, based on the simulation data and experience. Combined with the fact that the geometric characteristics of parts/components of the aero-engine rotor are not related to the measurement datum, Liu et al [7] proposed a datum error elimination method that makes the rotor characteristic matrix and assembly model more accurate, thereby improving the prediction effect of assembly accuracy. Mu et al [8] studied the construction method of composite processing components considering the manufacturing error and deformation factors of parts and proposed a new prediction method for aero-engine high-pressure rotor systems.…”