Abstract: Abstract： Hexapod multi-degree-of-freedom micro excitation system is mainly used to simulate onorbit micro vibration environment of the spacecraft payload. However, the existing control method can’t track the low frequency given sinusoidal acceleration, in view of the system which was strongly coupled and seriously nonlinear in the lowfrequency band, and the large phase lag of the controlled object. Aiming at this problem, an improved offline iteration control method combining lead compensation with the multiple frequency notch filter was proposed. The offline iteration performs compensation control, and the lead compensation further compensates the system phase, and the notch filter removes the nonlinear interference. The test results show that when tracking lowfrequency sinusoidal acceleration, compared with the classical offline iteration control method, the improved method has fast convergence and high control precision, compared with the existing adaptive sinusoidal vibration control method, and widens the lower limit of the acceleration control band from 14.5 Hz to 8 Hz, accorded with the requirement of accuracy. The effectiveness of the proposed method can be validated by the experimental results.

Key words: Keywords： micro vibration, nonlinear, phase, low frequency acceleration, offline iteration