Research And Design Of Vibration Isolation Platform Based On Accurate Modal Superposition Method

At present,most of the theories for solving the dynamic response of mechanical systems are based on undamped and proportional damping systems,and have large truncation errors and problems that are difficult to control.Therefore,based on the complex modal accurate modal superposition method,research and development of a solution system for calculating the dynamic response of non-proportional damping systems is of great significance for engineering practical applications.Based on the principle of complex modal superposition method,a precise vibration isolation platform based on modal superposition method is designed,and its simulation analysis and experimental verification are carried out.Firstly,it mainly summarizes the current method of harmonic response analysis,introduces the accurate modal superposition method when the current calculation method is insufficient,and summarizes the theory and basic calculation flow of the method.The proportional damping system calculates the process and significance of the dynamic response.Secondly,the vibration isolation principle based on the precise modal superposition method is deeply analyzed,and the vibration isolation platform design based on the precise modal superposition method is completed.The design of the active feedback control loop of the vibration isolation platform is analyzed,and the transmission rate under active control is analyzed.The results show that after the active vibration isolation control of this paper,the damping is further improved and the resonant peak of the system is also actively controlled by the ceiling damping.Compensation,from the system's transfer rate curve,to see this article makes.Thirdly,the vibration isolation performance of the whole vibration isolation platform based on the precise modal superposition method is studied through simulation.Two displacement interference signals below and above the natural frequency of the vertical direction are respectively set.When the proportional control parameter K of the PID controller is set to a specific value,the attenuation of the vibration signal lower than the natural frequency of the system can be achieved,and the attenuation rate is stimulated.The vibration frequency is 80% when it is 5HZ;and it can achieve a greater degree of attenuation of high frequency signals than without PID control.Then,two angular displacement interference signals lower than and higher than the natural frequency around the Z-axis rotation direction are respectively set.When the PID controller proportional control parameter K is set to a specific value,the attenuation of the vibration signal lower than the natural frequency of the system can be achieved.The attenuation rate is 65% at an excitation frequency of 5 Hz;and greater attenuation of high frequency signals can be achieved compared to without PID control.Finally,the platform drawings are processed,the prototype is obtained,the experimental platform is built,and the vibration isolation platform is tested for response.The results show that the input DC offset is 4A,the sinusoidal amplitude is 1A,the frequency is O.O5 Hz and 0.1Hz current signals respectively,and the displacement response amplitude of the load disc along the vertical axis z-axis is 0.22 mm,and the simulation model In contrast,the simulation error is 12%;the angular response amplitude of the load disk along the horizontal axis x-axis is 0.31°.Compared with the simulation model,the simulation error is 11%.Through simulation analysis and experiment,it can be proved that the vibration suppression capability of the platform has been further improved,and the entire vibration isolation platform is effective.