Novel Decoupling Control of Muti-Axis Shaking Table based on the Modified Adaptive Notch Filter

摘要

The multi-axis shaking table (MAST) is widely used in the vibration tests for high-rise buildings,bridges,large structures and so on.Due to the overturning moment and off-center load of the MAST,the dynamics cross-coupling disturbance occurs when the motion on one translational degree of freedom (DOF) couples into another rotary DOF or vice versa.The cross-coupling will reduce the tracking accuracy of the command waveform.A novel decoupling control for the sinusoidal command waveform and sweep sine command waveform is proposed based on the modified adaptive notch filter.The approach,inspired by the active noise control technology,takes the coupling motion as the noise for the coupled DOF,and cancels the cross-coupling disturbance by adding harmonics of the same frequency to the coupling motion,along with just the right phase and amplitude.A model of the plant is introduced to give the method critical phase information needed to adapt canceller coefficients.The experimental results indicate that the decoupling control can effectively reduce the dynamics coupling between the translational and rotary DOFs of the MAST.