Impact of step size on acceleration harmonic suppression of electro-hydraulic servo shaking table

Because of the nonlinear characteristics of electro-hydraulic servo shaking table, its acceleration output corresponding to a sinusoidal input contains higher harmonics which cause harmonic distortion. Using LMS adaptive filtering algorithm, an adaptive harmonic suppression algorithm is developed. The reference signals are filtered by an adaptive filter to obtain the harmonic suppression signal adding to the system input and auppressing the harmonic in the acceleration response. The test results show that the step size of the adaptive filter affects the convergence rate of harmonic suppression greatly. The influence of LMS adaptive filtering algorithm itself is analyzed.