A Study On Asymmetric Semi-active Vibration Control Technology Based On Negative Capacitance

With the continuous development of aerospace industry,the large-scale,low stiffness and flexibility of spacecraft is an important development trend.However,the spacecraft with flexible structure is more likely to produce low-frequency vibration which is difficult to suppress due to a small disturbance.Therefore,the vibration control of flexible structure is particularly important.Among various control methods,the semi-active control method has become the main vibration control method in the field of aerospace because of its good control performance and no need to model the structure accurately.As a kind of semi-active control technology of nonlinear synchronous switch damping(SSD),the SSD based on negative capacitance(SSDNC)technology has received extensive attention and research because its control performance is not affected by the inductance quality factor compared with the SSD based on inductance(SSDI)technology.Based on piezoelectric fiber composite,a negative capacitance asymmetric semi-active control circuit is designed,which is suitable for the range of its asymmetric working voltage.Under this control circuit,the asymmetric control voltage is generated,the driving ability of the driver is fully utilized,and the control performance is improved.The main contents and innovations of this paper are as follows:(1)An asymmetric SSDNC method is proposed.The relationship between the switching voltage and the bypass capacitance,which directly affects the control performance,is analyzed by theoretical formula.This method gives full play to the characteristics of negative capacitance,improves the positive control voltage and the control efficiency without changing the negative control voltage.(2)The theoretical results of asymmetric control circuit and switching voltage are verified by MATLAB/Simulink simulation,and the influence of bypass capacitance on system parameters is studied.With the increase of the bypass capacitance,the voltage asymmetric proportion coefficient and control performance of the system are improved,but the excessive bypass capacitance will cause the stability problem of the system.(3)Using the semi-active control system,the vibration suppression tests of cantilever beam and wing structure are carried out under different component parameters.The results show that the method can obtain stable asymmetric control voltage,and verify that the introduction of bypass capacitance can also increase the control effect of piezoelectric elements on the system.