Study On Simulation Of Vibration Isolation Performance Of Six Degrees Of Freedom Active And Passive Composite Vibration Isolation Platform

The vibration interference existing in the working environment is the key factor affecting the processing and measurement accuracy of the equipment.With the improvement of the processing and measurement accuracy requirements of the equipment,strict requirements are imposed on the vibration isolation and the positioning accuracy of the platform to ensure that the precision equipment can work normally.The positive and negative stiffness mechanism used in the traditional vibration isolation device can only provide the stiffness characteristic in one direction,and achieve the vibration isolation effect of single degree of freedom.To achieve multi-degree of freedom vibration isolation,each degree of freedom must be set accordingly.The positive and negative stiffness parallel device will increase the complexity of the device,and there are still some shortcomings in the case of more freedom requirements.Firstly,the design schemes of single-degree-of-freedom passive vibration isolation,active vibration isolation and active-passive combined vibration isolation are discussed in detail.The theoretical modeling and characteristic analysis of three vibration isolation schemes are carried out.The overall structural parameters of the six-degree-of-freedom active-passive composite vibration isolation platform are briefly analyzed.Then the structural design of the six-degree-of-freedom active-passive composite vibration isolation platform is emphasized,including the overall structural design of the vibration isolation platform,the actuator unit,the legs and the membrane.Leaf spring,hinge and eddy current position sensor structure design.The active and passive integrated vibration isolation control method was deeply analyzed.Secondly,the dynamic model of the vibration isolation platform is established,and the method for determining the parameters of the simulation model is analyzed.Based on the Adams software,the corresponding simulation analysis model of the six-degree-of-freedom active-passive composite vibration isolation platform is established,and the six-degree-of-freedom active-passive composite vibration isolation is applied.The modal analysis of the platform shows that the first and second orders of the six-degree-of-freedom active-passive composite vibration isolation platform have both in-plane vibration and torsional vibration,and the third order is torsional vibration around the z-axis.The fourth order is The vibration along the z-axis is mainly the torsion along the horizontal inner axis.It can be seen from the vibration mode distribution that the coupling characteristics of the unloaded active-passive composite vibration isolation platform are small.The response of several vibration isolation platforms is analyzed,and the transmission rate curves of several vibration isolation platforms are drawn using the dot method according to the numerical solution of the response.The results show that the active-passive composite vibration isolation platform designed in this paper has the characteristics of very low system natural frequency and high vibration isolation bandwidth,which can realize precise positioning and vibration isolation of six degrees of freedom.It adopts the connection mode of active and passive vibration isolation series to further It reduces the natural frequency of the system and expands the vibration isolation bandwidth,which can achieve excellent vibration isolation in the required vibration isolation frequency band.Finally,the experimental principle of the vibration isolation platform is briefly analyzed.Based on the rapid control prototype technology,the real-time control system of the six-degree-of-freedom active-passive composite vibration isolation platform is built,and the vibration isolation of the platform in the vertical direction and the two horizontal directions is completed.Testing of characteristics.The test results show that the six-degree-of-freedom active-passive composite vibration isolation platform has obvious vibration isolation effect in the three translation directions,the amplification of the resonance region is suppressed,and the high-frequency region also has a certain vibration isolation effect.