Precise measurement is the basis for the precise assembly of aeroengine rotors. However, due to the limitations of data application in the measurement process and the insufficient digitization of auxiliary assembly, the guided assembly after precise measurement heavily relies on manual analysis and operation. Moreover, due to the difficulty of fully utilizing measurement data of aeroengine rotors to guide assembly in existing assembly methods, it is hard to unify measurement and assembly processes, which limits the efficiency of aeroengine rotors assembly. According to the real-time response and high-fidelity interaction capability of the digital twin (DT) system, a coaxiality prediction model of aeroengine multistage rotors assembly and a cloud-based measurement data rapid interaction are established. Based on the large coaxiality measuring instrument, a DT system with measurement and real-time guidance for assembly is designed. Augmented reality device is used as the “sixth dimension” of the DT system to realize the digital measurement and assembly of aeroengine rotors. The experiment uses a certain type of engine three-stage rotors for measurement and assembly. The experimental results show that the large-scale coaxiality measuring instrument DT system can carry out accurate measurement and real-time assembly guidance for the engine, and achieve breakthroughs in engine assembly quality in multiple metrics, which significantly broadens the application dimension of precision measuring instruments.

Accurate measurement of geometric errors and mass properties is essential to aero-engine manufacturing. The measurement results can provide a reference for assembly. To address the problem of poor parallelism and unbalance prediction accuracy of hyperbolic paraboloid rotors, this paper designs a classifier. It achieves precise differentiation of the rotor surface by combining the Principal Component Analysis (PCA) and Support Vector Machine (SVM). The results show that the surface classifier accuracy is 99%. Then this paper combines the Genetic Algorithm (GA) and Back Propagation Neural Network (BPNN) to predict the parallelism and unbalance of the hyperbolic parabolic rotors. Compared with the traditional prediction model, the GA-BP neural network is more accurate in predicting the parallelism and unbalance of the multi-stage assembled rotors. The trend of the predicted results is more consistent with the experimental data. The prediction error of parallelism is reduced by 7.5 μm, and the maximum deviation of unbalance is reduced by 250.6 g·mm through the GA-BP neural network. The surface classifier and intelligent algorithm designed in this paper can provide a reference for rotor manufacturing and assembly.

To suppress the vibration of rotary parts, this paper established an unbalanced vibration response control model of rotary parts based on rotating axis coordinate system. This model considered the stacking transformation of geometric parameter errors and mass parameter errors of single stage rotor. First of all, the centroid transfer model based on the actual rotation axis was established, and the unbalanced excitation force vector of each stage of the rotor was studied. Secondly, the unbalanced excitation force vector of each stage of the rotor is substituted into the model of assembly vibration control based on the double constraints optimization strategy. Finally, the simulation analysis and the vibration experiment of three-stage rotor stacking assembly is carried out. The results show that the vibration of the engine rotor can be effectively suppressed by adjusting the assembly phase of the rotors, and the vibration amplitude of the combined rotor assembled by the double constraint optimization assembly strategy is 22.5% less than the vibration amplitude assembled by the direct assembly strategy. Besides, the coaxiality and the unbalance are reduced by 44.1% and 78.4%, which fully shows the advantages of the double constraint optimization assembly strategy.

The ultra-precise measurement of aero-engine rotor geometry error is the basis of its assembly, and adjusting the rotor coaxially with the measurement rotation axis is the key to ensure the measurement accuracy. As a typical adjustment device for rotor alignment, the traditional method of applying a four-degree-of-freedom centering and tilting table for adjustment does not take into account the coupling effect caused by the position of each adjustment motor not being perfectly perpendicular to each other, this paper gives the calibration method of the angle between each adjustment motor and the starting position of the angle grating, analyzes the principle of eccentricity and tilt adjustment and deduces the coupling solution method. Subsequently, the size of the coupling between the two adjustments is analyzed and an efficient adjustment method is given for its mechanical structure characteristics. The experimental results show that the platform can effectively decouple and quickly converge to the setting values of 0.3 µm and 0.5′′ for different initial eccentric distance and tilt angle. With the same adjustment accuracy, the number of adjustments is reduced by more than 50% and more than 37.5%, respectively, compared with the non-decoupled method.

A dynamic analysis model of the unbalanced vibration response of a single-rotor system is established to study the corresponding mechanism of the unbalanced excitation force and vibration response caused by the deviation of the rotor mass centroid in this paper, and finally to achieve the combined rotor vibration suppression. First, the installation of multi-stage rotors during vibration was studied, and the rotor mass centroid transfer model in the rotating coordinate system was established to obtain the unbalanced excitation force vectors of the rotors at all levels based on the traditional stacking assembly method and axiality measurement. Second, the rotor unbalance excitation force vectors were substituted at all levels to establish the finite element analysis model of the single-rotor system. Finally, a simulation analysis was carried out for the stacking assembly of the three-stage rotor, and the rotor test piece was used for the vibration experiment. The results show that the optimal assembly phase of the multi-stage rotor obtained by the dynamic analysis model of the unbalanced vibration response of the single-rotor system can effectively suppress the vibration of the combined rotor.