Flexible Cantilever Active Vibration Control Based On The PPF Algorithm

With the development of space technology, large space structure has been widely used in the field of aerospace as the focus of the study of space technology. However, the modal frequency of the existing large space structure is relatively low in general and the damping is always small, so if there is a disturbance outside, the vibration will last a very long time. Large space structures are always distributed parameter systems, we call these the high-controlled systems, this kind of system has many vibration modes, when we design the controller based on a reduced order model in these high-controlled system will result in spillover and make the closed-loop system stability margin smaller.As the active vibration control algorithm can not meet the requirements of accuracy of spatial structure, we do some study on a flexible cantilever beam system based on PPF (Positive Position Feedback) algorithm in this paper. Although the direct velocity feedback algorithm which previously used is unconditionally stable, it is an ideal algorithm and has a lot of limits in practical application. The PPF algorithm is non-dynamic stability and is not sensitive to overflow, and this algorithm can be root-locus and have the relationship between inherent resonant frequency and negative real part of the characteristic equation root to achieve the most optimal design of the actuator parameters. We make use of these advantages of PPF algorithm, first of all, through the relationship between structural frequency and characteristic equation root we select the optimal parameters, get the most suitable actuator frequency and gain for the system and then change the frequency and gain of different values, we prove that the most optimal parameters enable the amplitude of vibration attenuation and the decay time to a minimum, thereby they play a very good role in vibration suppression. This paper also do further studies, expand single-mode state to multi-mode, through experiments apply PPF algorithm to high-modal system could still have better vibration suppression effect, so as to show the superiority and practicality of PPF algorithm .