High accuracy multi axes micro-vibration control based on adaptive harmonic cancellation

Six degrees of freedom (6-DOF) vibration excitation system is a high accuracy platform commonly used to simulate the micro-vibration environment. When the operating frequency is near resonance frequencies, the error between practical output and desired output could be large because of the harmonic signal included in the response signal. To eliminate harmonic disturbance, a multiple-input multiple-output (MIMO) vibration control method contains adaptive harmonic cancellation (AHC) algorithm is proposed. Firstly, the structural dynamic characteristics of the 6-DOF vibration excitation system are analyzed. Then, based on the traditional vibration MIMO control method, the AHC is adopted and added in control loop for vibration tests. Experiment shows that the harmonic distortion is greatly reduced and the control precision has been effectively improved by using proposed approaches.