Research Of Environmental Vibration Measurement And Evaluation Methods Of Precision Equipment

As the processing and measuring accuracy of precision equipment increases, environmentfoundation vibration whose amplitude is comparatively small has become an important factorthat influences precision machining and measuring accuracy. This thesis mainly studiesenvironmental vibration measurement and evaluation methods of precision equipment. Thestudy is conducted from three aspects including vibration testing and processing ofenvironment foundation, performance testing of vibration isolator and vibration requirementsand evaluation of isolating platform, based on the fact that most precision equipment isinstalled with isolating device.This thesis summarizes the existing environmental vibration evaluation methods based onvibration limits, and analyzes advantages of VC criteria. Methods of choosing sensors andregulations to be followed when installing sensors are discussed. A variety of vibration signalprocessing technique is provided for different testing purposes.The principle of a typical air float type vibration isolator is analyzed and its equivalentdynamical model is established. An experimental scheme is designed for testing the isolatingperformance of the vibration isolation system, and the methods of increasing signal to noiseratio in transmissibility measurement are discussed.The independent component analysis method is used to remove power interference invibration signal. Numerical integral and polynomial fitting are adopted to solve the problemof trend term which arises in converting acceleration signal to velocity signal.For precision equipment installed with isolation system, the isolation platform becomesits actual foundation. An evaluation method of vibration isolation foundation based on VCcriteria is proposed and an application example is given to prove its effectiveness.