Assembly Error Analysis And Health Monitoring Method Research Of Harmonic Drive Mechanism

As a key component of the on-board mechanical movable antenna,the accuracy and health of the harmonic drive mechanism directly affects the life and accuracy of the rotating parts of the satellite;once the harmonic drive mechanism fails,the mechanical movable antenna loses its rotating function,which has a serious impact on the satellite application.In order to meet the accuracy requirements of the harmonic drive mechanism and ensure its healthy and stable operation,this paper analyzes the error composition and error frequency characteristics affecting the harmonic drive mechanism;analyzes the harmonic drive flexibility characteristics and tribological characteristics,constructs a nonlinear dynamics simulation model of the harmonic drive system,obtains the output dynamic response of the harmonic drive system,and provides a nonlinear simulation model for the accuracy analysis;in order to solve the problems in practical engineering,the typical moving parts screening cannot quantitatively identify minor damage and the shaft system alignment accuracy cannot be quantitatively measured,an optimal variational modal decomposition method based on the whale algorithm is proposed to identify the early defects of rolling bearing rolling body faults,and based on this method,the spectrum analysis and error feature extraction of misalignment errors generated in the assembly process of the harmonic drive mechanism are carried out.First,the factors affecting the accuracy of the harmonic drive mechanism are analyzed,focusing on each error of the harmonic drive.At the same time,the error frequency characteristics of each error of the harmonic drive mechanism are analyzed,which provides a theoretical basis for the subsequent development of a health detection method based on the frequency domain characteristics of the harmonic drive mechanism errors.Secondly,the dynamics analysis,simulation and modeling of the system were carried out on the basis of the flexible characteristics and tribological characteristics of the harmonic reducer.The regression models of the motor friction and the harmonic drive system considering the flexibility of the flexible wheel and the mechanism friction are constructed separately by using the statistical analysis method,and Simulink simulation software is applied to simulate them,and the least squares method is used to determine each parameter term of the system design.By analyzing the torque output characteristics and angular output characteristics of the system obtained by testing the constructed system dynamics simulation model,the non-linear characteristics of the system are determined.Finally,the study focuses on the misalignment error of the rotating unit during the assembly process and the identification of the early failure of the bearing during the screening process.A health monitoring method based on the whale algorithm for optimal variational modal decomposition is proposed,and the method is applied to the early defect identification of rolling bearing rolling element faults and harmonic reducer misalignment error frequency extraction and measurement.Using this method for early defect identification of bearings,it can clearly distinguish whether the bearings are defective or not and identify the location of the damage.The method is used to extract and measure the frequency of misalignment errors generated during the assembly process and compared with the conventional method,showing the superiority of the method in anti-modal mixing and providing a dynamic measurement method for determining the misalignment errors of the mechanism.