Study On Multifrequency Method Of Active Vibration Control For Helicopter

As an innovative and high technology, the technology of active control of structural response(ACSR) has caught world wide’s attention. And the adaptive control algorithm is one of the most important technologies. For ACSR, the traditional active control algorithm of parallel multi-frequency narrowband is verified to be simple and effective. But its’ stability and inductive frequencies are annoying problems. To solve these problems, an improved control algorithm is brought forward in this dissertation, and simulations and experiments have been conducted to verify the validity of the algorithm. The main work of this dissertation includes:1) Analysis of the stability and inductive frequencies of the traditional multifrequency adaptive Fx-LMS algorithm is conducted. Based on the analysis results,the improved adaptive control algorithm of parallel multi-frequency in time domain is brought forward. Considering the practical requirement of helicopter vibration attenuation, the algorithm was designed for the composition of kW and 2kW vibration frequencies.2) Active control simulations of single-input/single-output and four-input/two-output based on the proposed control algorithm are conducted based on a simple FEM helicopter model. Different conditions are tested, included simple harmonic disturbance, complicated disturbance, and time-changed main channel and passive channel, and the effects of some important control parameters are studied as well.3) Based on the SEED-DEC33 DSP, the improved adaptive control algorithm is fulfilled under CCS environment using C language. Choosing a kind of piezoelectric stack actuator as force output device, which can control multifrequency vibration, the whole experiment system is built finally.4) Experimental studies are conducted on a free-free beam, including single-input/single-output and four-input/two-output.The satisfied vibration reduction results verified the effectiveness of the improved multifrequency adaptive control algorithm brought forward in this dissertation.