Research And Application On The Control Technology For The Seismic Simulation Shaking Table System Of Tri-axial And Six Degrees Of Freedom

With the new seismic problems exposed by the big earthquakes in recent years,new requirements were put forward for the seismic simulation shaking table test,and the research on control technology of seismic simulation shaking table had become a hot issue.The studies not only have a very high application value,but also have a very important test technical support on anti-seismic theory,such as the contol technology of table,virtual seismic simulation shaking table,nonlinear advanced control algorithm,control system algorithm of multiple shakeing table ect.As the research object of the seismic simulation shaking table system of tri-axial and six degrees of freedom in Xi’an University of architecture and technology,the studies were carried out in the basic control theory and benchmark performance of the shaking table,virtual seismic simulation shaking table and so on.The main and research contents are as follows:(1)On the basis of the existing control theory,the compositions of the electro-hydraulic servo control system of the shaking table were introduced,and in-depth theoretical studies on the working principles of actuator,energy storage and three stage servo valve was carried out.The motion control theory of shaking tale was analysed including the principles of closed-loop control system and Three-Variable Control(TVC),and the basic contol of system was achieved.The control principles of table were studied including motion forms and degree of freedom control,and the stability and good working condition of shaking table system were ensured.The basic principles of adaptive control were analysed including Amplitude/Phase Control(APC),Adaptive Harmonic Control(AHC),Adaptive Inverse Control(AIC),On-line Iteration(OLI),and the precision control of system was achieved.In addition,through the theoretical research on compensation techniques,such as the geometric cross coupling compensation,overturning torque compensation,eccentric load compensation,force balance compensation,differential pressure stability compensation and other special control compensation technology,the principles of compensation function were analysed and the reproducibility accuracy of system was achieved.(2)Testing methods of benchmark performance to the shaking table were put forward,and the test index system of the static and dynamic properties was set up.Based on the static performance of shaking table,the displacement accuracy,rotation angle and acceleration signal-to-noise ratio were tested,and the test data was analysed to meet the design requirements.On the basis of the dynamic properties,the maximum displacements,speeds and accelerations were tested in X,Y,Z direction under the three case of no-load,20 t,30t.Finally,the maximum function curve and optimal performance of shaking table were gained.The aacceleration unevenness and the overturning moment(80t?m)of the shaking table sysyterm were teset.The data shows high accuracy of system feedback and excellent performance to meet the design requirements.(3)A comprehensive introduction to the dynamic foundation,table and its support system,vibration system,hydraulic source system and digital control system was given,which provides reference for the future construction of the shaking table.A model to the virtual seismic simulation shaking table system of tri-axial and six degrees of freedom was constructed in Matlab-Simulink.Amplitude frequency response and motion attitude were gained.The results showed that the virtual seismic simulation shaking table system had the same states with the real shaking table,and can accurately simulate the system nonlinear dynamic properties including the oil column resonance and so on.The virtual seismic simulation shaking table system had been the function of off-line parameter adjustment.(4)A shaking table test for the model of 5-storeyed reinforced concrete frame structure was comducted.The study on Parameters including TVC and AIC was carried out,and can meet the requirements of test.Dynamic properties and responses were gained,and the dynamic response law was analysed.The result showed that the frame structure had good anti-seismic performance.(5)A shaking table test for the GIS electric equipment was comducted.The artificial ground motion was designed and synthesized and the study on Parameters including TVC and AIC was carried out,which can meet the requirements of control accuracy.According to the test,the dynamic properties and responses including acceleration,displacement,strain were gained,which provide a theortiacal basis for the tests of anti-sesmic performance of GIS electric equipments.