Operational Modal Analysis And Control Parameter Optimization For High-Frequency Reciprocating Lightweight Mechanism

High-frequency reciprocating light-weight structure is widely used in chip manufacturing and packaging.Such structures exhibit flexible characteristics due to multi-dimensional running inertial impact during high-frequency motion,and the relative motion between components causes the structure to become a time-varying system.The system generates complex responses under the influence of these uncertain factors,which directly affects the chip positioning accuracy of the terminal.At the same time,in order to reduce the operational inertia impact,topology optimization analysis and lightweight design are carried out.Conventional vibration sensors are not only difficult to install under high-frequency operation,but the additional quality also changes the characteristics of the structure,leading to inaccurate results.At present,there is no effective test method to obtain the accurate vibration response of a lightweight structure under high-frequency reciprocating operation,and thus it is impossible to suppress the vibration of such structure through the dynamic method.Due to the early research on chip sorting in foreign countries,a complete industrial chain has been formed and result in the monopoly of key equipment and technology.Most of the key equipment such as China's chip industry sorting relies on imports.Therefore,the research and development of chips with independent intellectual property rights plays an important role in breaking the monopoly of technology and promoting the development of China's chip industry.In this paper,the LED chip high-speed sorting machine is selected as the representative of the high-frequency operation lightweight structure.The experimental research has been conducted in the following aspects: the identification of the sensitive components and the operational modal parameters of the sorting machine,the obtaining of the trajectory of the rotating shaft axis,and the suppression positioning vibration of the sorting arm end and chip-oriented sorting testing.The main work of this paper includes the following aspects:In this paper,the symbolic regression method based on genetic programming is proposed to identify the weak components of the mechanical structural system.A simulation experiment on a spring-damper system with five DOF and an operational experiment on the high-frequency sorting arm system are conducted to verify the effectiveness of the method,respectively.The result shows that this method can accurately identify the weak components of the system.The method quantifies the weak characteristics of the sorting arm system,and make the subsequent research more targeted.The existing modal identification method cannot accurately identify the dynamic characteristics of lightweight structures under high-frequency operation.This paper proposed a strain modal analysis method,which combines the operational modal analysis method and the strain modal identification method.The method of identifying the modal parameters of the high-frequency reciprocating lightweight structure under operation was analyzed,and the dynamic characteristics of such structures were analyzed.For the modal analysis method,the process of manually filtering the modal parameters is needed,and the experimental results have the problem of human error.In this paper,a new method,which combines the modal analysis method and the particle swarm optimization algorithm,was proposed to realize the automatic screening of the modal parameters of the structure under operation and can avoid the influence of human factors.The method was applied to the measured data in the running state of the sorting arm,and the natural frequency values of the first few modes were accurately identified.In this paper,the vibration characteristics of the sorting arm under high-frequency operation were studied.The unbalance of the rotating shaft of the sorting arm system was analyzed.The influence of the torsional vibration of the rotating shaft on the sorting arm was studied.The end vibration was suppressed by adjusting the running excitation mode of the sorting arm system.The multi-body dynamics analysis technology was applied to optimize the control function of the sorting arm rotating electric machine,and the inertial impact was introduced under the high-frequency operation of the sorting arm mechanism.The results of this paper show that the proposed method can effectively obtain the vibration response of the high-frequency reciprocating lightweight structure under operation,and the modal parameters in the running state were identified,and the dynamic characteristics under the operational state were analyzed,which is of great significance for suppressing the inertial vibration of the structure under high-frequency operation and improving the high-speed positioning accuracy in the field of chip sorting and packaging.